JP5783179B2 - Transition metal compound-containing nanoparticles and method for producing the same, transition metal compound-containing nanoparticle dispersed ink and method for producing the same, device having a hole injection transport layer, and method for producing the same - Google Patents

Description

  The present invention relates to a transition metal compound-containing nanoparticle and a production method thereof, a transition metal compound-containing nanoparticle-dispersed ink and a production method thereof, and an organic device such as an organic electroluminescence element and a hole injection transport layer including a quantum dot light-emitting element And a method for manufacturing the same.

  Devices using organic substances are expected to expand to a wide range of basic elements and applications such as organic electroluminescence elements (hereinafter referred to as organic EL elements), organic transistors, organic solar cells, organic semiconductors and the like. Other devices having a hole injecting and transporting layer include quantum dot light emitting elements and oxide compound solar cells.

The element structure of the organic EL element is composed of cathode / organic layer / anode. This organic layer has a two-layer structure composed of a light emitting layer / a hole injection layer in the early organic EL element, but now, in order to obtain a high luminous efficiency and a long driving life, an electron injection layer / electron Various multilayer structures such as a five-layer structure composed of a transport layer / light emitting layer / hole transport layer / hole injection layer have been proposed.
These layers other than the light emitting layer such as the electron injection layer, the electron transport layer, the hole transport layer, and the hole injection layer have the effect of facilitating the injection and transport of charges to the light emitting layer, or block the electron current and the positive current by blocking. It is said that there are effects such as maintaining the balance of the hole current and suppressing diffusion of light energy excitons.

For the purpose of improving charge transport ability and charge injection ability, attempts have been made to increase the electrical conductivity by mixing an oxidizing compound with a hole transport material.
In Patent Documents 1 to 4, a metal oxide that is a compound semiconductor is used as an oxidizing compound, that is, an electron-accepting compound. For the purpose of obtaining a hole injection layer having good injection characteristics and charge transfer characteristics, for example, a thin film is formed by vapor deposition using a metal oxide such as vanadium pentoxide or molybdenum trioxide, or molybdenum oxide and A mixed film is formed by co-evaporation with an amine-based low molecular weight compound.
In Patent Document 5, as an attempt to form a coating film of vanadium pentoxide, a solution in which oxovanadium (V) tri-i-propoxide oxide is dissolved as an oxidizing compound, that is, an electron accepting compound, is used. There is a production method in which a charge transfer complex is formed as a vanadium oxide by hydrolysis in water vapor after formation of a mixed coating film with a transporting polymer.
In Patent Document 6, as an attempt to form a coating film of molybdenum trioxide, fine particles produced by physically pulverizing molybdenum trioxide are dispersed in a solution to prepare a slurry, which is then applied to inject holes. It describes that a long-life organic EL element is formed by forming a layer.

On the other hand, an organic transistor is a thin film transistor that uses an organic semiconductor material composed of a π-conjugated organic polymer or a small organic molecule in a channel region. A general organic transistor includes a substrate, a gate electrode, a gate insulating layer, source / drain electrodes, and an organic semiconductor layer. In an organic transistor, by changing the voltage (gate voltage) applied to the gate electrode, the amount of charge at the interface between the gate insulating film and the organic semiconductor film is controlled, and the current value between the source electrode and the drain electrode is changed. Perform switching.
Introducing a charge transfer complex into an organic semiconductor as an attempt to improve the on-current value of the organic transistor and stabilize the device characteristics by reducing the charge injection barrier between the organic semiconductor layer and the source or drain electrode This is known to increase the carrier density in the organic semiconductor layer near the electrode (for example, Patent Document 7).

Thus, in devices, attempts have been made to reduce the charge injection barrier by applying an oxidizing material to the hole injection transport material. However, even if an oxidizing material as disclosed in Patent Documents 1 to 7 is used as the hole injecting and transporting material, it is difficult to realize a long-life element, or the life needs to be further improved. Although the molybdenum oxide, an inorganic compound, has relatively high characteristics, there is a problem that it is insoluble in a solvent and the solution coating method cannot be used. Patent Document 6 describes that a charge injection layer was prepared by screen printing using a slurry in which molybdenum oxide fine particles having an average particle diameter of 20 nm were dispersed in a solvent. However, as in Patent Document 6, MoO ₃ powder is used. For example, it is very difficult to produce fine particles having a uniform particle size on a scale of 10 nm or less in response to a request for forming a hole injection layer of about 10 nm. In addition, molybdenum oxide fine particles produced by pulverization are more difficult to stably disperse in a solution without agglomeration. If the solution of the fine particles is unstable, only a film with large irregularities and poor smoothness can be formed during the production of the coating film, which causes a short circuit of the device.
The film formability and the thin film stability are greatly related to the lifetime characteristics of the device. In general, the lifetime of an organic EL element is the luminance half-life when continuously driven by a constant current drive or the like, and an element having a longer luminance half-time has a longer driving lifetime.

  In response to such a problem, the present inventors include at least a transition metal compound containing a transition metal oxide and a transition metal and a protective agent, or at least including a transition metal compound containing a transition metal oxide and a protective agent. A device capable of achieving a long life while forming a hole injecting and transporting layer by a solution coating method by using transition metal-containing nanoparticles containing a metal for a hole injecting and transporting layer was found (Patent Document 8). .

  On the other hand, metal-containing nanoparticles having a particle size of 100 nm or less have been used in various fields such as abrasives, various functional fillers, conductive paste additives, catalysts, and the like, taking advantage of the characteristics. Among these, metal oxide-containing nanoparticles are used for phosphors, catalysts, abrasives, transparent conductive films, and the like.

JP 2006-155978 A JP 2007-287586 A Japanese Patent No. 3748110 JP-A-9-63771 SID 07 DIGEST p. 1840-1843 (2007) JP 2008-041894 A JP 2002-204012 A JP 2009-290204 A

  The solution coating method that applies to the substrate using a solvent does not require a large-scale vapor deposition device compared to the vacuum vapor deposition method, can be expected to simplify the manufacturing process steps, has high material utilization efficiency, and is inexpensive. Since there is a merit that it is possible to increase the area of the base material, it is desired to form as many functional layers as possible by a solution coating method. In a device, it is often desired to form an organic layer by a solution coating method using a hydrophobic solvent after a hole injection / transport layer is formed by a solution coating method. However, when the upper organic layer is applied, the lower hole injecting and transporting layer may be redissolved. Depending on the degree of re-dissolution, the film thickness of the hole injecting and transporting layer becomes non-uniform, and there is a possibility that in-plane characteristic variations on the surface of the hole injecting and transporting layer and device short-circuiting may occur. Therefore, there is a demand for a material that can form a stable hole injecting and transporting layer with a good film forming property by a solution coating method even when an organic layer is formed adjacently by a solution coating method, and can improve the lifetime characteristics of the device. It has been.

  In addition, since applications are expected in various fields, novel metal compound-containing nanoparticles that can be stably dispersed in a solvent are demanded.

This invention is made | formed in view of the said problem, The 1st objective is to provide the novel metal compound containing nanoparticle which can be disperse | distributed stably in a solvent.
A second object of the present invention is a transition metal which is a material capable of forming a stable hole injection / transport layer by a solution coating method even when an organic layer is formed adjacently by a solution coating method using a hydrophobic solvent. It is to provide compound-containing nanoparticles.
The third object of the present invention is to provide a method for producing the above transition metal compound-containing nanoparticles.
A fourth object of the present invention is to provide a transition metal compound-containing nanoparticle-dispersed ink in which novel transition metal compound-containing nanoparticles are stably dispersed in a solvent.
A fifth object of the present invention is to provide a method for producing the transition metal compound-containing nanoparticle dispersed ink.
A sixth object of the present invention is to provide a device capable of forming a hole injection transport layer by a solution coating method and capable of achieving a long lifetime while being easy in the manufacturing process.
A seventh object of the present invention is to provide a method for manufacturing the above device.

The transition metal compound-containing nanoparticle according to the present invention includes at least one transition metal compound selected from the group consisting of transition metal carbide oxide, transition metal nitride oxide, and transition metal sulfide oxide, a linking group, and hydrophilicity. protective agent having an organic group is linked by the linking group containing a group or dispersible in a hydrophilic solvent, the hydrophilic group, a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group state, and are one or more selected from the group consisting of sulfo group, sulfonate and ammonium groups,
Unlike the hydrophilic group, the linking group is one or more selected from the group consisting of functional groups represented by the following general formulas (1a) to (1o),
The organic group is selected from the group consisting of a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 or more carbon atoms, an aromatic hydrocarbon group, a heterocyclic group, and combinations thereof. and wherein the der Rukoto 1 or more.

  The transition metal compound-containing nanoparticles according to the present invention (hereinafter sometimes simply referred to as “nanoparticles”) are different from the case of using an inorganic compound such as molybdenum oxide, and the like. Since the protective agent having a group is linked by a linking group, the hydrophilic solvent has dispersibility and high dispersion stability. In addition, it must be stably dispersible in a solvent while containing a specific transition metal compound such as one or more selected from the group consisting of transition metal carbide oxide, transition metal nitride oxide and transition metal sulfide oxide. Therefore, application as a new nanoparticle is expected in various fields.

  In the nanoparticle according to the present invention, the specific transition metal compound is a specific transition metal compound-containing nanoparticle protected by a protective agent having an organic group containing a hydrophilic group. Although the transport layer can be formed and the manufacturing process is easy, the charge transfer complex can be formed, the hole injection property can be improved, and the organic layer can be formed adjacently by a solution coating method using a hydrophobic solvent. Since it becomes a highly stable film, it is particularly suitable as a material for forming a hole injecting and transporting layer.

  Since the nanoparticles according to the present invention can be formed into a thin film by a solution coating method using a hydrophilic solvent, the merit in the manufacturing process is great. From the hole injecting and transporting layer to the light emitting layer can be sequentially formed on the substrate having a liquid repellent bank only by the coating process. Therefore, after the hole injection layer is deposited by high-definition mask deposition or the like as in the case of an inorganic compound molybdenum oxide, a hole transport layer or a light emitting layer is formed by a solution coating method, and a second electrode is further formed. Compared to a process such as vapor deposition, there is an advantage that a device can be manufactured at a low cost.

In addition, it is considered that the nanoparticles according to the present invention have a high reactivity of the specific transition metal compound contained in the nanoparticles and are likely to form a charge transfer complex. Therefore, the nanoparticle according to the present invention is suitable for use as a hole injection transport layer, and the device including the hole injection transport layer containing the nanoparticle according to the present invention has low voltage driving, high power efficiency, long It is possible to realize a long-life device.
Furthermore, by selecting the kind of the nanoparticle protective agent, it is easy to make it multifunctional, for example, to impart functionality such as charge transportability or adhesion to the device.

  In addition, the nanoparticle according to the present invention has high reactivity of the specific transition metal compound contained in the nanoparticle, has a high specific surface area derived from a minute size, and has many reactive active sites per unit weight. Therefore, it is also suitable for a catalyst application in which nanoparticles are appropriately supported on a support surface.

  In the transition metal compound-containing nanoparticles of the present invention, the transition metal of the transition metal compound is one or more metals selected from the group consisting of molybdenum, tungsten, vanadium and rhenium, so that the drive voltage of the device It is preferable from the viewpoint of lowering and improving the device life.

In the transition metal compound-containing nanoparticle of the present invention, the hydrophilic group is selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group. because it is 1 or more that is preferable from the viewpoint of dispersion stability of the hydrophilic solvent.

In the transition metal compound-containing nanoparticles of the present invention, the linking group is different from the hydrophilic group, and is one or more selected from the group consisting of functional groups represented by the following general formulas (1a) to (1o). since there are those preferred in view of stability of the membrane.

（式中、Ｚ_１、Ｚ_２及びＺ_３は、各々独立にハロゲン原子又はアルコキシ基を表し、Ｒは水素原子又はメチル基を表わす。）

(In the formula, Z ₁ , Z ₂ and Z ₃ each independently represent a halogen atom or an alkoxy group, and R represents a hydrogen atom or a methyl group.)

In the transition metal compound-containing nanoparticles of the present invention, the protective agent is represented by the following general formula [I], and has functions of a hydrophilic group and a linking group, and aggregation of the nanoparticles. It is preferable from the viewpoint that a sufficient distance can be secured to prevent the above.
Formula [I]
XYZ
(In the general formula [I], X is a hydrophilic group, Y is a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms and / or an aromatic having 6 to 40 carbon atoms. Represents a group hydrocarbon group, and Z represents a linking group.)

  In the transition metal compound-containing nanoparticles of the present invention, the hydrophilic solvent preferably has a water solubility (20 ° C.) of 50 g / L or more. In this case, it is possible to ensure incompatibility between the transition metal compound-containing nanoparticles and the hydrophobic solvent used for forming the adjacent layer and the adjacent layer material, and the amount of re-dissolution in the adjacent layer during the application process is reduced. Can be made.

The first method for producing a transition metal compound-containing nanoparticle according to the present invention includes (A) a step of carbonizing a transition metal and / or transition metal complex to form a transition metal carbide,
(B) a step of protecting the transition metal carbide obtained in the step (A) with a protective agent having an organic group containing a linking group; and
(C) a step of oxidizing the transition metal carbide having an organic group obtained in the step (B) to obtain a transition metal carbide oxide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent a protective agent having an organic group containing a sex group, seen including a step of exchanging the protective agent having an organic group containing a hydrophilic group,
The hydrophilic group is at least one selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group;
Unlike the hydrophilic group, the linking group is at least one selected from the group consisting of functional groups represented by the general formulas (1a) to (1o),
The organic group is selected from the group consisting of a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 or more carbon atoms, an aromatic hydrocarbon group, a heterocyclic group, and combinations thereof. It is one or more types .

The method for producing the second transition metal compound-containing nanoparticle according to the present invention includes (a) a step of protecting the transition metal and / or the transition metal complex with a protective agent having an organic group containing a linking group,
(B) carbonizing the transition metal or transition metal complex having an organic group obtained in step (a) to form a transition metal carbide having an organic group; and
(C) a step of oxidizing the transition metal carbide having an organic group obtained in the step (b) to form a transition metal carbide oxide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent a protective agent having an organic group containing a sex group, seen including a step of exchanging the protective agent having an organic group containing a hydrophilic group,
The hydrophilic group is at least one selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group;
Unlike the hydrophilic group, the linking group is at least one selected from the group consisting of functional groups represented by the general formulas (1a) to (1o),
The organic group is selected from the group consisting of a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 or more carbon atoms, an aromatic hydrocarbon group, a heterocyclic group, and combinations thereof. It is one or more types .

The third method for producing a transition metal compound-containing nanoparticle according to the present invention comprises (α) carbonizing a transition metal and / or transition metal complex to form a transition metal carbide,
(Β) a step of oxidizing the transition metal carbide obtained in the step (α) to form a transition metal carbide oxide, and
(Γ) including the step of protecting the transition metal carbide obtained in the step (β) with a protective agent having an organic group containing a linking group to form a transition metal carbide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent a protective agent having an organic group containing a sex group, seen including a step of exchanging the protective agent having an organic group containing a hydrophilic group,
The hydrophilic group is at least one selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group;
Unlike the hydrophilic group, the linking group is at least one selected from the group consisting of functional groups represented by the general formulas (1a) to (1o),
The organic group is selected from the group consisting of a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 or more carbon atoms, an aromatic hydrocarbon group, a heterocyclic group, and combinations thereof. It is one or more types .

  According to the method for producing nanoparticles according to the present invention, nanoparticles having dispersibility in a solvent and capable of being formed into a thin film or supported on a carrier surface by a solution coating method can be obtained.

  In the manufacturing method of the 1st thru | or 3rd transition metal compound containing nanoparticle which concerns on this invention, since the process protected by the said protective agent can be performed in a solvent, the protection process can be performed stably. preferable.

  In the manufacturing method of the 1st thru | or 3rd transition metal compound containing nanoparticle which concerns on this invention, performing the process made into the said transition metal carbide at 150-400 degreeC makes a particle size uniform and an unreacted transition metal. It is preferable from the point which suppresses the production | generation of a complex.

  In the method for producing the first to third transition metal compound-containing nanoparticles according to the present invention, it is possible to maintain the dispersion stability in the reaction solution by performing the transition metal carbide step in an argon gas atmosphere. This is preferable.

  The first transition metal compound-containing nanoparticle-dispersed ink according to the present invention includes the transition metal compound-containing nanoparticle and a hydrophilic solvent.

  The second transition metal compound-containing nanoparticle-dispersed ink according to the present invention includes one or more compounds (U) selected from the group consisting of transition metal nitrides and transition metal sulfides, a linking group, and a hydrophilic group. In order to prepare the transition metal compound-containing nanoparticles of the present invention and / or to form a film containing the transition metal compound-containing nanoparticles of the present invention, which contains a protective agent having an organic group and a hydrophilic solvent It is used. The nanoparticle-dispersed ink is suitably used for forming a film containing the transition metal compound-containing nanoparticles by a solution coating method.

  The method for producing a transition metal compound-containing nanoparticle dispersed ink according to the present invention includes a transition metal complex containing any atom of carbon, nitrogen or sulfur, a protective agent having an organic group containing a linking group and a hydrophilic group, and a boiling point. Has a step of heating a solution containing a hydrophilic solvent at 160 to 260 ° C. at 150 to 250 ° C., and is used for preparing the transition metal compound-containing nanoparticles of the present invention.

A device according to the present invention is a device having two or more electrodes opposed to each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes,
The hole injection transport layer contains at least the transition metal compound-containing nanoparticles according to the present invention.

  The device of the present invention is suitable for an embodiment containing a charge transporting layer containing a charge transporting compound that can be dissolved and / or dispersed in a hydrophobic solvent adjacent to the hole injection transporting layer.

  In the device of the present invention, two or more kinds of the transition metal compound-containing nanoparticles may be contained in the hole injecting and transporting layer. In this case, by using nanoparticles with different work functions (HOMO) and allowing holes to move stepwise via the two types of nanoparticles, the energy barrier between adjacent layers can be further lowered, or positive There is a merit that the hole injection / transport property more than the function of a single particle can be obtained by separately preparing and mixing nanoparticles specialized for hole injection property and particles specialized for hole transport property.

  The device of the present invention is suitably used as an organic EL element containing an organic layer including at least a light emitting layer.

  The device of the present invention is an organic transistor having a gate electrode, an insulating layer, a source electrode and a drain electrode, and an organic semiconductor layer on a substrate, wherein the transition metal compound is formed on at least a part of the surface of the source electrode and the drain electrode. It is also suitably used as an organic transistor having contained nanoparticles.

A first device manufacturing method according to the present invention is a method for manufacturing a device having two or more electrodes opposed to each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes.
Forming a hole injecting and transporting layer on any of the layers on the electrode using the first transition metal compound-containing nanoparticle-dispersed ink.

A method for producing a second device according to the present invention is a method for producing a device having two or more electrodes facing each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes,
Using the second transition metal compound-containing nanoparticle-dispersed ink, forming a hole injecting and transporting layer on any layer on the electrode; and
A step of oxidizing the compound (U).

  According to the first and second device manufacturing methods according to the present invention, it is possible to provide a device capable of forming a hole injecting and transporting layer by a solution coating method and facilitating the manufacturing process, while achieving a long life. Is possible.

  In the second device manufacturing method according to the present invention, the step of oxidizing the compound (U) may be performed after the step of forming the hole injection transport layer.

  In the second device manufacturing method according to the present invention, after the step of preparing the transition metal compound-containing nanoparticle-dispersed ink and before the step of forming the hole injection transport layer, the compound (U ) May be performed.

  In the second device manufacturing method according to the present invention, in the step of oxidizing the compound (U), it is preferable to use any one of a heating means, a light irradiation means and a means for causing active oxygen to act.

  The first and second device fabrication methods according to the present invention include a charge transporting compound that can be dissolved and / or dispersed in a hydrophobic solvent adjacent to the hole injection transport layer and a hydrophobic solvent. It is suitable for an embodiment including a step of forming a charge transport layer by applying a neutral solution.

  The first and second device manufacturing methods according to the present invention include an aspect in which the device is an organic EL element containing an organic layer including at least a light emitting layer, a gate electrode, an insulating layer, a source electrode, and a drain on a substrate. It is an organic transistor having an electrode and an organic semiconductor layer, and is suitable for an embodiment having the transition metal compound-containing nanoparticles on at least a part of the surfaces of the source electrode and the drain electrode.

The present invention can provide a novel transition metal compound-containing nanoparticle that can be stably dispersed in a hydrophilic solvent, and a novel transition metal compound-containing nanoparticle-dispersed ink using the nanoparticle.
The transition metal compound-containing nanoparticles of the present invention are dispersible in a solvent, and can be formed into a thin film or supported on a carrier surface by a solution coating method. According to the transition metal compound-containing nanoparticles according to the present invention, it is possible to form a hole injecting and transporting layer of a device that can achieve a long life while the manufacturing process is easy.
The method for producing transition metal compound-containing nanoparticles of the present invention can easily produce such transition metal compound-containing nanoparticles.
The device of the present invention can achieve a long life while the manufacturing process is easy.
According to the device manufacturing method of the present invention, it is possible to provide a device that can achieve a long life while the manufacturing process is easy.

It is the schematic diagram which showed an example of the use of the transition metal compound containing nanoparticle which concerns on this invention. It is the schematic diagram which showed the order of the process of the manufacturing method of the 1st thru | or 3rd transition metal compound containing nanoparticle which concerns on this invention. 1 is a conceptual cross-sectional view showing a basic layer configuration of a device according to the present invention. It is a cross-sectional schematic diagram which shows an example of the laminated constitution of the organic EL element which is one Embodiment of the device which concerns on this invention. It is a cross-sectional schematic diagram which shows another example of the layer structure of the organic EL element which is one Embodiment of the device which concerns on this invention. It is a cross-sectional schematic diagram which shows another example of the layer structure of the organic EL element which is one Embodiment of the device which concerns on this invention. It is a cross-sectional schematic diagram which shows an example of the layer structure of the organic transistor which is another embodiment of the device which concerns on this invention. It is a cross-sectional schematic diagram which shows another example of the layer structure of the organic transistor which is another embodiment of the device which concerns on this invention. It is a figure which shows the evaluation result of the current density about the organic diode obtained by Example 1, 2 and the comparative example 1. FIG.

  Hereinafter, the transition metal compound-containing nanoparticles and the production method thereof, the transition metal compound-containing nanoparticle-dispersed ink, the device, and the production method thereof according to the present invention will be described.

[Transition metal compound-containing nanoparticles]
The transition metal compound-containing nanoparticles according to the present invention include a hydrophilic group in one or more transition metal compounds selected from the group consisting of transition metal carbide oxide, transition metal nitride oxide, and transition metal sulfide oxide. A protective agent having an organic group is linked by a linking group and is dispersible in a hydrophilic solvent.

  The transition metal compound-containing nanoparticle according to the present invention is different from particles formed by simply pulverizing a transition metal compound, and a protective agent having an organic group containing a hydrophilic group is linked by a linking group on the nanoparticle surface. Yes. Since the protective agent includes a hydrophilic group and a linking group, when the protective agent is linked to the specific transition metal compound by the linking group, the hydrophilic group contained in the protective agent is attached to the surface of the specific transition metal compound. Since it is disposed on the covered organic group, the nanoparticle surface becomes hydrophilic, has dispersibility in the hydrophilic solvent, and has high dispersion stability. Here, whether or not the nanoparticles can be dispersed in the hydrophilic solvent is determined, for example, by adding 1 mg of the nanoparticles to 1 mL of the hydrophilic solvent having a solubility in water (20 ° C.) of 50 g / L or more, at room temperature (20 ° C. ) For 1 hour and then left at 20 ° C. for 1 hour, and if the dry weight of the precipitate is less than 0.1 mg, it can be dispersed and the dry weight of the precipitate is 0.1 mg or more. If it becomes, it will be judged that dispersion | distribution is impossible.

  A hydrophilic solvent is a solvent that is compatible with water at a certain ratio. As the hydrophilic solvent, water or solubility in water (20 ° C.) is 50 g / L or more and can be used without any particular limitation. The hydrophilic solvent is preferably a solvent that can be mixed with water at an arbitrary ratio. Examples of the hydrophilic solvent to be dispersed include water, glycerin, 1-propanol, 2-propanol, 1-butanol, ethylene glycol, propylene glycol, methyl diglycol, isopropyl glycol, butyl glycol, isobutyl glycol, methyl propylene diglycol, Propylene propylene glycol, butyl propylene glycol, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, ethylene glycol monoethyl ether, ethylene group Glycol monomethyl ether, cyclohexanone, mention may be made of diacetone alcohol.

  Further, the transition metal compound-containing nanoparticle according to the present invention includes a specific transition metal compound of at least one selected from the group consisting of transition metal carbide oxide, transition metal nitride oxide, and transition metal sulfide oxide. However, since it can be stably dispersed in a hydrophilic solvent, application as a novel nanoparticle is expected in various fields. Here, the nanoparticle means a particle having a diameter of the order of nm (nanometer), that is, less than 1 μm.

  The nanoparticles according to the present invention may have a single structure or a composite structure, and may have a core / shell structure, an alloy, an island structure, or the like. The transition metal compound contained in the nanoparticles is at least one selected from the group consisting of transition metal carbide oxide, transition metal nitride oxide, and transition metal sulfide oxide. In addition to these, borides, selenides, halides, complexes, and the like may be included.

By including transition metal carbide oxide, transition metal nitride oxide or transition metal sulfide oxide in the nanoparticles, the value of ionization potential is optimized or changes due to oxidation from unstable oxidation number +0 metal By suppressing in advance, it is possible to reduce the drive voltage and improve the element life in the device.
Among these, it is preferable that transition metal compounds that are oxides having different oxidation numbers coexist in the nanoparticles. By including transition metal compounds with different oxidation numbers in combination, hole transport and hole injection properties are appropriately controlled by the balance of oxidation numbers, which can reduce drive voltage and improve device lifetime. It becomes possible. Note that transition metal atoms and compounds of various valences such as oxides and borides may be mixed in the nanoparticles depending on the processing conditions.
In the transition metal carbide oxide, transition metal nitride oxide, and transition metal sulfide oxide, at least a part of the transition metal carbide, transition metal nitride, and transition metal sulfide only needs to be oxidized. Preferably, in each of transition metal carbide, transition metal nitride, and transition metal sulfide, the surface layer of about 1 nm is preferably oxidized.

  Further, when the nanoparticle contains a specific metal compound such as transition metal carbide oxide, transition metal nitride oxide, or transition metal sulfide oxide, it can be used for various applications as described later.

  As the transition metal of the transition metal compound contained in the nanoparticles of the present invention, the group 3-11 metal element may be appropriately selected from the transition metal elements according to the intended use. Specifically, for example, as a hole injecting and transporting layer application in a device, molybdenum, tungsten, vanadium, rhenium and the like can be cited from the charge injecting and transporting property of the metal compound. Examples of the catalyst application include molybdenum, vanadium, titanium, iron, cobalt, nickel, tungsten, palladium, platinum, and gold. Examples of wiring applications include gold, silver, copper, indium, and molybdenum. Moreover, silver, gold | metal | money etc. are mentioned as a sensor use using surface enhanced Raman scattering (SERS) etc. Examples of magnetic recording medium applications include iron, cobalt, nickel, palladium, platinum, and the like. Examples of ferroelectric applications include titanium and zirconium.

Among them, the transition metal of the transition metal compound is one or more metals selected from the group consisting of molybdenum, tungsten, vanadium, and rhenium, and because of its high reactivity, it is easy to form a charge transfer complex. This is preferable from the viewpoint of reducing the driving voltage and improving the device life in the device.
In addition, it is known in the oxide film formation method using a vacuum evaporation method that each element of tungsten, vanadium, and rhenium is oxidized similarly to molybdenum, and a hole injection transport characteristic is acquired. For example, for tungsten, “ADVANCED MATERIALS” 2008, 20 p. 3839-3843 and vanadium are described in “J. PHYS. D: APPL. PHYS.” 41 (2008) 062003 (4pp), and rhenium is described in “APPLIED PHYSICS LETTERS” 91 0111113 (2007).

  The transition metal carbide oxide, transition metal nitride oxide and transition metal sulfide oxide contained in the nanoparticles of the present invention are preferably contained in a total of 90 mol% or more in the transition metal compound. Further, among these three kinds of transition metal compounds, it is preferable that a single transition metal compound is contained in an amount of 90 mol% or more from the viewpoint of lowering the driving voltage and improving the element life in the device. More preferably, it is contained in an amount of at least mol%.

(Protective agent)
In the present invention, the protective agent protecting the nanoparticles has a linking group and an organic group containing a hydrophilic group.
A protective agent is linked to a nanoparticle by a linking group, and the nanoparticle surface is protected by covering the nanoparticle surface with an organic group containing a hydrophilic group. Increases dispersion stability.
The protective agent may be a low molecular compound or a high molecular compound.

  The linking group is not particularly limited as long as it has an effect of linking with a transition metal and / or a transition metal compound. The connection includes adsorption and coordination, but is preferably a chemical bond such as an ionic bond or a covalent bond. The number of linking groups in the protective agent may be any number as long as it is one or more in the molecule. However, when it is desired to obtain more uniform nanoparticles, it is preferable that different substituents are employed for the linking group and the hydrophilic group described later, and there is one linking group in one molecule of the protective agent.

  The linking group contained in the protective agent is selected from the functional groups represented by the following general formulas (1a) to (1o) from the viewpoint of the action of linking to the transition metal and / or transition metal compound on the nanoparticles. One or more are preferable.

（式中、Ｚ_１、Ｚ_２及びＺ_３は、各々独立にハロゲン原子又はアルコキシ基を表し、Ｒは水素原子又はメチル基を表わす。）

(In the formula, Z ₁ , Z ₂ and Z ₃ each independently represent a halogen atom or an alkoxy group, and R represents a hydrogen atom or a methyl group.)

  On the other hand, as the hydrophilic group contained in the protective agent, a substituent having an action of making the nanoparticle surface hydrophilic while covering the nanoparticle surface with an organic group is used. Examples of the hydrophilic group include a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group. Among them, the hydrophilic group has at least one selected from the group consisting of a hydroxyl group, a carbonyl group, an amino group, a thiol group, a sulfo group, a sulfonate, and an ammonium group, and has the ability to link with a transition metal compound. It is preferable from a comparatively weak point, Furthermore, it is preferable that it is 1 or more types selected from the group which consists of a hydroxyl group, a carbonyl group, a thiol group, a sulfo group, and a sulfonate.

  In the protective agent, the linking group and the hydrophilic group may be the same type of substituent, but at least a substituent that functions as a linking group and a substituent that functions as a hydrophilic group in one molecule. Is included one by one. However, when the linking group and the hydrophilic group are the same, the protective agent has a plurality of linking groups, and there is a concern that the nanoparticles may be bonded and aggregated via the linking group. From the standpoint of maintenance, in the protective agent, the linking group and the hydrophilic group are preferably different from each other. In particular, it is more preferable that the protective agent includes one or more hydrophilic groups that are not easily bonded to the nanoparticles and one linking group that is easily bonded to the nanoparticles.

The organic group contained in the protective agent may be a group containing carbon and has a carbon number of 1 or more, preferably 1 to 30, more preferably 2 to 25, and still more preferably 4 to 25. Chain, branched or cyclic saturated or unsaturated aliphatic hydrocarbon groups and / or aromatic hydrocarbon groups and / or heterocycles having 6 to 40, more preferably 12 to 34, more preferably 12 to 26 carbon atoms. A cyclic group etc. are mentioned. The carbon number here does not include the carbon number of the substituent of the aliphatic hydrocarbon group, aromatic hydrocarbon group, and heterocyclic group.
Among them, as organic groups, those that do not have a bulky structure such as a cyclic structure in the part directly bonded to the linking group can be protected densely without defects when the protective agent protects the surface via the linking group. From the point that it is preferable that the number of carbon atoms in the linear structure is 2 or more, the distance between the transition metal compounds of the nanoparticle core can be sufficiently maintained, and aggregation of the nanoparticles can be prevented. preferable.
On the other hand, when the protective agent contains an aromatic hydrocarbon and / or a heterocyclic ring as an organic group, it has a charge transporting property or a charge transporting property having an adjacent aromatic hydrocarbon and / or a heterocyclic ring. The dispersion stability of the film can be improved by improving the adhesion with the compound.

  Examples of linear or branched saturated or unsaturated aliphatic hydrocarbon groups include methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, sec-butylene group, tert-butylene group, various pentylene groups, Examples include various hexylene groups, various pentylene groups, various hexylene groups, various heptylene groups, various octylene groups, various nonylene groups, and various decylene groups.

  Specific examples of the aromatic hydrocarbon and / or heterocyclic ring include benzene, triphenylamine, fluorene, biphenyl, pyrene, anthracene, carbazole, phenylpyridine, trithiophene, phenyloxadiazole, phenyltriazole, and benzimidazole. , Phenyltriazine, benzodiathiazine, phenylquinoxaline, phenylene vinylene and phenylsilole, and combinations of these structures.

  When nanoparticles are used in the device, the protective agent preferably has a charge transporting group. In this case, the compatibility with the charge transporting compound and the improvement of the charge transporting property can contribute to a longer driving life. A charge transporting group is a group whose chemical structural group has the property of having electron or hole drift mobility, and as another definition, it is known that charge transporting performance such as Time-Of-Flight method can be detected. This method can be defined as a group that can obtain a detection current resulting from charge transport. When the charge transporting group cannot exist by itself, the compound in which a hydrogen atom is added to the charge transporting group may be a charge transporting compound. Examples of the charge transporting group include a residue from which a hydrogen atom has been removed in a hole transporting compound (arylamine derivative, carbazole derivative, thiophene derivative, fluorene derivative, distyrylbenzene derivative, etc.) as described later. It is done.

It is preferable that the protective agent is represented by the following general formula [I] from the viewpoint of having a function of each of a hydrophilic group and a linking group and securing a sufficient distance to prevent aggregation of nanoparticles. .
Formula [I]
XYZ
(In the general formula [I], X is a hydrophilic group, Y is a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms and / or an aromatic having 6 to 40 carbon atoms. Represents a group hydrocarbon group, and Z represents a linking group.)

Specific examples when the protective agent is a low molecular weight compound are not limited to these, but include thioglycolic acid, thioglycol, malonic acid, maleic acid, succinic acid, glutaric acid, glycolic acid, glycine, 4-hydroxythiophenol, 4-mercaptophenylacetic acid, biphenyl-4,4′-dicarboxylic acid, benzidine, 4- (4-aminophenyl) benzonitrile, 4,4′-diformyltriphenylamine, tris (4- Formylphenyl) amine, N, N, N ′, N′-tetrakis (4-aminophenyl) benzidine and the like.
In addition, when the protective agent is a low molecular compound having a molecular weight of 1000 or less, since the protective agent covering the nanoparticle surface is thin, the transition metal-containing compound surface approaches the adjacent layer compound and interacts with it. The transition metal-containing compound is preferable because it can be expected to contribute to the improvement of hole injection properties. Although it does not specifically limit as a minimum of the molecular weight of a protective agent, It can be set as a standard that it is 50 or more.

  When the protective agent is a polymer compound, a polymer compound containing two or more functional groups functioning as a linking group and a hydrophilic group per molecule can be appropriately selected and used. As the polymer compound, a polymer having a repeating unit is preferably used, and the weight average molecular weight is, for example, greater than 1000 and about 50000 or less. The weight average molecular weight here refers to a polystyrene equivalent value by GPC (gel permeation chromatography). Specific examples of the polymer compound used as the protective agent include, but are not limited to, polyvinylpyrrolidone, polyglycolide, poly (2-acrylamido-2-methyl-1-propanesulfonic acid), poly ( Acrylamide-acrylic acid) copolymer and the like.

The protective agent preferably has a solubility (20 ° C.) in the hydrophilic solvent of 10 g / L or more, more preferably 50 g / L or more, from the viewpoint that the nanoparticles can be dispersed in the hydrophilic solvent. .
In addition, it is preferable to select and use a compound having an octanol-water partition coefficient logP of −10 to 2 as the protective agent. When a protective agent having an octanol-water partition coefficient log P in the above range is used, the protective agent has appropriate hydrophilicity, and the nanoparticles can be dispersed in a hydrophilic solvent. Especially, when the adhesiveness with an adjacent organic layer is important, the compound whose octanol-water partition coefficient logP is -5-2 is preferable.
Here, the octanol-water partition coefficient logP is a parameter representing the balance between hydrophobicity / hydrophilicity. logP is the partition coefficient of a substance in two solvent systems to n-octanol and water, with the logarithm logP = log (Co / Cw) in common for the concentration Co in n-octanol and the concentration Cw in water of a compound. Defined. In recent years, a method for obtaining logP by calculation has been proposed, and as a useful method, software “Marvin Calculation Plugin” of ChemAxon can be mentioned. In the present invention, logP is a value calculated using this software “Marvin Calculation Plugin”.

  In the nanoparticles of the present invention, the content ratio of the transition metal compound and the protective agent is appropriately selected depending on the application, and is not particularly limited, but the protective agent is 10 to 40 parts by mass with respect to 100 parts by mass of the transition metal compound. Preferably there is.

The average particle diameter of the nanoparticles of the present invention is not particularly limited, and can be, for example, 0.5 nm to 999 nm, and may be appropriately selected depending on the application. The average particle size is preferably 0.5 nm to 50 nm, and more preferably 0.5 nm to 20 nm. In the case of forming a thin film having a thickness of 20 nm or less, the thickness is further preferably 15 nm or less, particularly preferably in the range of 1 nm to 10 nm. This is because it is difficult to produce a product having a particle size that is too small. On the other hand, if the particle size is too large, the surface area per unit mass (specific surface area) may be small and the desired effect may not be obtained, and the surface roughness of the thin film may be large and shorts may occur frequently. Because.
Here, the average particle diameter is the number average particle diameter measured by the dynamic light scattering method. In the state dispersed in the hole injecting and transporting layer, the average particle diameter is measured with a transmission electron microscope (TEM). Obtained by selecting an area where it is confirmed that 20 or more nanoparticles exist from the image obtained by using the image, measuring the particle diameter of all the nanoparticles in this area, and determining the average value. Value.

(Use of transition metal compound-containing nanoparticles)
The nanoparticle according to the present invention has a very high dispersion stability in a hydrophilic solvent, and is a specific one or more selected from the group consisting of transition metal carbide oxide, transition metal nitride oxide and transition metal sulfide oxide. It is a novel nanoparticle containing a transition metal compound.
Therefore, it can be suitably used in the form of an ink dispersed uniformly in a hydrophilic solvent with high dispersion stability.

  Furthermore, since the dispersion stability is very high in the solvent, a thin film of nm order having high temporal stability and high uniformity can be formed. Since the thin film is hydrophilic, even if an organic layer is formed adjacent to the thin film by a solution coating method using a hydrophobic solvent, the thin film is a stable film without being redissolved. Conversely, on the organic layer formed by the solution coating method using a hydrophobic solvent, a layer containing the nanoparticles of the present invention is formed adjacent to the organic layer by a solution coating method using a hydrophilic solvent. However, the organic layer can form a highly stable thin film without being redissolved. That is, it can be set as the thin film laminated body by which a hydrophobic organic thin film and the hydrophilic coating film containing the nanoparticle which concerns on this invention are laminated | stacked adjacently.

  In addition, on the organic layer formed by the solution coating method using a hydrophobic solvent, when the highly hydrophobic nanoparticles are dispersed and coated in the hydrophobic solvent, the surface layer portion of the organic layer is By re-dissolving, the nanoparticle is embedded in the surface layer portion of the organic layer. However, when nanoparticles dispersible in the hydrophilic solvent of the present application are used, the nanoparticles according to the present invention expose the surface of the nanoparticles on the carrier 5 such as a hydrophobic organic layer as shown in FIG. It can be set as the aspect supported in the made state. The carrier for supporting the nanoparticles can be used without being limited to the hydrophobic organic layer, and the nanoparticles according to the present invention are preferably used for applications in which the surface of the nanoparticles is supported as a function by being supported on the surface of the carrier. Can do.

  From the above, the nanoparticles according to the present invention can be used for various applications. For example, additives such as friction modifiers, antiwear agents, and antioxidants used in device materials, particularly hole injecting and transporting materials, catalysts, lubricating oils in devices, and the like.

The nanoparticle according to the present invention is suitable as a device material in one embodiment.
In the nanoparticle according to the present invention, the specific transition metal compound is a specific transition metal compound-containing nanoparticle protected by a protective agent having an organic group containing a hydrophilic group. Although the transport layer can be formed and the manufacturing process is easy, the charge transfer complex can be formed, the hole injection property can be improved, and the organic layer can be formed adjacently by a solution coating method using a hydrophobic solvent. Since it becomes a highly stable film, it is particularly suitable as a material for forming a hole injecting and transporting layer. Since the dispersion stability is very high in a hydrophilic solvent, a highly uniform nm order thin film can be formed. Since the thin film has high temporal stability and uniformity, it is difficult to short-circuit even when used in a device.

  Since the nanoparticles according to the present invention can be formed into a thin film by a solution coating method using a hydrophilic solvent, the merit in the manufacturing process is great. For example, in an organic EL element, a hole injection / transport layer to a light emitting layer can be sequentially formed on a substrate having a liquid repellent bank only by a coating process. Therefore, after the hole injection layer is deposited by high-definition mask deposition or the like as in the case of an inorganic compound molybdenum oxide, a hole transport layer or a light emitting layer is formed by a solution coating method, and a second electrode is further formed. Compared to a process such as vapor deposition, there is an advantage that a device can be manufactured at a low cost.

In addition, it is considered that the nanoparticles according to the present invention have a high reactivity of the specific transition metal compound contained in the nanoparticles and are likely to form a charge transfer complex. Therefore, the device provided with the hole injecting and transporting layer containing nanoparticles according to the present invention can realize a low voltage drive, high power efficiency, and long life device.
Furthermore, by selecting the kind of the nanoparticle protective agent, it is easy to make it multifunctional, for example, to impart functionality such as charge transportability or adhesion to the device.
The device mode will be described in detail later.

The nanoparticles according to the present invention can also be used as a catalyst. When used as a catalyst responsible for the electrode reaction of a fuel cell, the transition metal compound in the nanoparticles is preferably a transition metal carbide, particularly molybdenum carbide.
When the nanoparticles according to the present invention are used as a catalyst, the carrier for supporting the nanoparticles may be appropriately selected depending on the reaction carried by the catalyst. For example, carbon nanotubes, carbon nanohorns, carbon nanofilaments, graphene, graphite, etc. Examples thereof include carbon materials having electrical conductivity.

(Method for producing transition metal compound-containing nanoparticles)
The first method for producing a transition metal compound-containing nanoparticle according to the present invention includes (A) a step of carbonizing a transition metal and / or transition metal complex to form a transition metal carbide,
(B) a step of protecting the transition metal carbide obtained in the step (A) with a protective agent having an organic group containing a linking group; and
(C) a step of oxidizing the transition metal carbide having an organic group obtained in the step (B) to obtain a transition metal carbide oxide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent A step of replacing a protective agent having an organic group containing a functional group with a protective agent having an organic group containing a hydrophilic group.

The method for producing the second transition metal compound-containing nanoparticle according to the present invention includes (a) a step of protecting the transition metal and / or the transition metal complex with a protective agent having an organic group containing a linking group,
(B) carbonizing the transition metal or transition metal complex having an organic group obtained in step (a) to form a transition metal carbide having an organic group; and
(C) a step of oxidizing the transition metal carbide having an organic group obtained in the step (b) to form a transition metal carbide oxide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent A step of replacing a protective agent having an organic group containing a functional group with a protective agent having an organic group containing a hydrophilic group.

The third method for producing a transition metal compound-containing nanoparticle according to the present invention comprises (α) carbonizing a transition metal and / or transition metal complex to form a transition metal carbide,
(Β) a step of oxidizing the transition metal carbide obtained in the step (α) to form a transition metal carbide oxide, and
(Γ) including the step of protecting the transition metal carbide obtained in the step (β) with a protective agent having an organic group containing a linking group to form a transition metal carbide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent A step of replacing a protective agent having an organic group containing a functional group with a protective agent having an organic group containing a hydrophilic group.

FIG. 2 is a schematic view showing the order of the steps of the method for producing the first to third transition metal compound-containing nanoparticles according to the present invention.
(I) of FIG. 2 shows an example of the method for producing the first transition metal compound-containing nanoparticle according to the present invention. The transition metal and / or the transition metal complex 10 is carbonized to form a transition metal carbide 20, Next, the surface of the transition metal carbide is protected by linking a linking group of the protective agent 30 having an organic group containing a linking group, and then the transition metal carbide is oxidized to form a transition metal carbide oxide 40 as a transition metal. Compound-containing nanoparticles 1 are obtained. Here, the protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or when the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group. Furthermore, the transition metal compound-containing nanoparticles 1 can be obtained by replacing the protective agent having an organic group containing a hydrophobic group with a protective agent having an organic group containing a hydrophilic group (not shown). obtain. When the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, the protective agent having an organic group containing the hydrophobic group is replaced with a protective agent having an organic group containing a hydrophilic group. The process to be performed may be performed before or after the (C) oxidation process. However, since there is a concern that the surface state of the nanoparticles is changed by the oxidation process and the dispersibility is lowered, (C) at the same time as the oxidation process or (C ) It is preferred after the oxidation step.

  (Ii) of FIG. 2 shows an example of a method for producing the second transition metal compound-containing nanoparticle according to the present invention, and an organic group containing a linking group on the surface of the transition metal and / or transition metal complex 10. Then, the transition metal and / or transition metal complex 10 is carbonized to form a protected transition metal carbide 20 (having an organic group including a hydrophilic group). Then, the transition metal carbide is oxidized to obtain transition metal compound-containing nanoparticles 1 as the transition metal carbide oxide 40. Here, the protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or when the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group. Furthermore, the transition metal compound-containing nanoparticles 1 can be obtained by replacing the protective agent having an organic group containing a hydrophobic group with a protective agent having an organic group containing a hydrophilic group (not shown). obtain. When the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, the protective agent having an organic group containing the hydrophobic group is replaced with a protective agent having an organic group containing a hydrophilic group. The step to be performed may be before or after the (b) carbonization step and / or the (c) oxidation step, but the (b) carbonization step and / or (c) the oxidation step changes the surface state of the nanoparticles and the dispersibility is increased. Since there is a concern about the decrease, (c) the same as the oxidation step or (c) after the oxidation step is preferable.

  (Iii) of FIG. 2 shows an example of a method for producing the third transition metal compound-containing nanoparticle according to the present invention. The transition metal and / or the transition metal complex 10 is carbonized to form a transition metal carbide 20. Next, the transition metal carbide is oxidized to form a transition metal carbide oxide 40. Subsequently, it protects by connecting the connection group of the protective agent 30 which has the organic group containing a connection group on the surface of the transition metal carbide oxide 40, and the transition metal compound containing nanoparticle 1 is obtained. Here, the protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or when the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group. Furthermore, the transition metal compound-containing nanoparticles 1 can be obtained by replacing the protective agent having an organic group containing a hydrophobic group with a protective agent having an organic group containing a hydrophilic group (not shown). obtain.

In the step (A) of the first method for producing a transition metal compound-containing nanoparticle according to the present invention, as the transition metal, any of the above-mentioned nanoparticles can be used, and the description thereof is omitted here.
When carbonizing a transition metal, a transition metal carbide can be obtained by adding a ligand containing a carbon atom such as hexacarbonyl or acetylacetonate and heating.

  The transition metal complex may be a transition metal complex containing a carbon atom in the ligand, and is preferably a transition metal complex that is decomposed in a solvent at as low a temperature as possible. For example, molybdenum hexacarbonyl, tungsten hexacarbonyl, iron pentacarbonyl, cobalt carbonyl, cyclopentadienyl cobalt dicarbonyl and transition metal carbonyl complexes such as pentacarbonyl chlororhenium, vanadium acetylacetonate, titanium diisopropoxide bis (acetyl Acetonato), iron acetylacetonate, nickel acetylacetonate, palladium acetylacetonate, platinum acetylacetonate, silver acetylacetonate, copper acetylacetonate, indium acetylacetonate, acetylacetonate complexes of transition metals, tetrakis ( Dimethylamido) titanium, tetrakis (diethylamido) titanium, tetrakis (ethylmethylamido) titanium, bis (diethylamido) bis Dimethylamido) titanium, bis (cyclopentadienyl) vanadium, ferrocene, bis (cyclopentadienyl) cobalt, bis (cyclopentadienyl) nickel, platinum octaethylporphyrin, trimethyl (methylcyclopentadienyl) platinum, trichloro (Pyridine) gold, silver phthalocyanine, etc. are mentioned.

As a method of carbonizing the transition metal and / or transition metal complex, a method such as heating can be used. For example, when heating, the transition metal and / or transition metal complex is carbonized by heating at 150 to 400 ° C. can do. From the point of making the particle size uniform and reducing the particle size, it is preferable to heat at 200 to 350 ° C., more preferably 250 to 350 ° C.
The heating in the carbonization step is preferably performed in a solvent from the viewpoint that the entire nanoparticle can be uniformly carbonized. Moreover, it is preferable to perform the process made into a transition metal carbide in argon gas atmosphere from the point which maintains the dispersion stability in a reaction solution.

  In the step (B), as the protective agent, those mentioned in the above nanoparticles can be used, and therefore the description thereof is omitted here.

  The protecting step of connecting the linking group of the protective agent having an organic group containing a linking group to the surface of the transition metal carbide or the like in the step (B) is preferably performed in a solvent. Specifically, it is preferably performed by heating and stirring in a solvent in which the protective agent is dispersed. At this time, as a solvent, a solvent having a boiling point of heating temperature + 10 ° C. or higher is selected and used. It is preferable to perform in the presence of a solvent having a boiling point of 200 ° C. or higher from the viewpoint that protection with a protective agent can be performed uniformly and stably in a high temperature environment.

In the step (C), examples of the oxidation method include a heating means, a light irradiation means, a means for causing active oxygen to act, and the like may be used in combination as appropriate.
Examples of the heating means include a hot plate and an oven. As heating temperature, 50-250 degreeC is preferable.
An example of the light irradiation means is an ultraviolet irradiation device.
Examples of the means for causing active oxygen to act include a method in which active oxygen is generated by using ultraviolet rays, and a method in which active oxygen is generated by irradiating ultraviolet rays onto a photocatalyst such as titanium oxide.
In the said means, since a difference arises in interaction between nanoparticles and the interaction with a hole transportable compound of a nanoparticle by heating temperature, light irradiation amount, and amount of active oxygen, it is preferable to adjust suitably.
Moreover, when oxidizing, in order to oxidize a transition metal carbide efficiently, it is preferable to carry out in oxygen presence.

  When the protective agent in the protection step is a protective agent having an organic group containing a linking group and a hydrophobic group, the protective agent having an organic group containing the hydrophobic group has an organic group containing a hydrophilic group The step of exchanging with a protective agent is performed in a solvent in which nanoparticles protected with a protective agent having an organic group containing a hydrophobic group can be dispersed and in which the protective agent having an organic group containing a hydrophilic group can be dissolved. be able to. For example, the protective agent can be exchanged by stirring in a solvent such as chloroform for about 4 to 72 hours at a temperature of about room temperature (20 ° C.) to about 60 ° C. In addition, when the function of connecting the linking group of the hydrophilic protective agent to the linking group of the hydrophobic protective agent is stronger, the time required for replacement can be further shortened. Moreover, about the temperature heated at the process of replacement | exchange, it can raise in temperature by using a high boiling-point solvent, and it can shorten further the time which replacement | exchange of a protective agent changes by raising in temperature, but when it raises in temperature, it will be a nanoparticle. Since the nanoparticles are aggregated due to an increase in the amount of the protective agent desorbed from the surface, it is preferable that the temperature at which the protective agent is replaced be as low as possible in a temperature range where the protective agent can be replaced.

  Also in the second and third nanoparticle production methods, the carbonization method, the oxidation method, and the protection method using the protective agent can use the respective methods of the first nanoparticle production method.

Furthermore, in the method for producing nanoparticles of the present invention, two or more of the above steps may be performed simultaneously.
For example, in the first method for producing nanoparticles, the step (A) of carbonizing the transition metal and / or transition metal complex and the step (B) of protecting with a protective agent may be performed simultaneously.

  Moreover, although the manufacturing method of the said nanoparticle is a manufacturing method of the nanoparticle in case a transition metal compound is included as a transition metal compound, a transition metal nitride oxide or a transition metal sulfide oxide is included as a transition metal compound. In some cases, the carbonization raw material added to the transition metal may be a nitriding raw material or a sulfur raw material, or the transition metal complex may be replaced with a material containing a nitrogen atom or a sulfur atom in the same manner as described above.

  Examples of the sulfiding raw material added when sulfiding the transition metal include sulfur, dodecanethiol, benzenethiol and bistrimethylsilylsulfur.

  Examples of the transition metal complex containing a nitrogen atom include tungsten pentacarbonyl-N-pentyrisonitrile and triamine molybdenum tricarbonyl.

[Transition metal compound-containing nanoparticle dispersed ink]
The first transition metal compound-containing nanoparticle-dispersed ink according to the present invention includes the transition metal compound-containing nanoparticle and a hydrophilic solvent.

  The second transition metal compound-containing nanoparticle-dispersed ink according to the present invention includes at least one compound (U) selected from the group consisting of transition metal carbide, transition metal nitride, and transition metal sulfide, a linking group, and a hydrophilic group. It contains a protective agent having an organic group containing a functional group and a hydrophilic solvent. The ink is used to prepare the transition metal compound-containing nanoparticles of the present invention and / or to form a film containing the transition metal compound-containing nanoparticles of the present invention.

  According to the first and second transition metal compound-containing nanoparticle-dispersed inks according to the present invention, a device that can be used for the above-mentioned applications while having a simple manufacturing process, for example, can achieve a long life. Is possible.

  The transition metal compound-containing nanoparticles contained in the first transition metal compound-containing nanoparticle-dispersed ink and the protective agent contained in the second transition metal compound-containing nanoparticle-dispersed ink are the same as those mentioned for the nanoparticles. Therefore, explanation here is omitted.

(Compound (U))
One or more compounds (U) selected from the group consisting of transition metal carbide, transition metal nitride, and transition metal sulfide contained in the second transition metal compound-containing nanoparticle-dispersed ink are described in the above nanoparticles. It is a precursor of transition metal carbide oxide, transition metal nitride oxide and transition metal sulfide oxide, and the corresponding oxide is obtained by oxidizing them. In each of the compounds (U), at least a part of the transition metal and / or transition metal complex may be carbonized, nitrided, or sulfided.
As a method for obtaining the transition metal carbide, a conventionally known method can be used. For example, the transition metal carbonization method described in the first method for producing nanoparticles can be used.
Further, when obtaining the transition metal nitride and the transition metal sulfide, for example, as described in the first method for producing nanoparticles, the carbonization raw material to be added to the transition metal is a nitriding raw material or a sulfide raw material, Alternatively, the transition metal complex may be replaced with the one containing a nitrogen atom or sulfur atom, and the above transition metal carbonization method may be performed.

(Hydrophilic solvent)
As the hydrophilic solvent contained in the first and second transition metal compound-containing nanoparticle dispersed ink, the first transition metal compound-containing nanoparticle dispersed ink includes the transition metal compound-containing nanoparticle and the second transition metal. The compound-containing nanoparticle-dispersed ink is not particularly limited as long as the compound (U) and other components such as a protective agent and a hole transporting compound to be described later are dissolved or dispersed as required.
As such a hydrophilic solvent, a hydrophilic solvent as described in the description of the nanoparticles can be appropriately used.

A suitable application of the transition metal compound-containing nanoparticle-dispersed ink is a hole injection / transport layer ink for forming a hole injection / transport layer used in a device described later.
When the transition metal compound-containing nanoparticle-dispersed ink is used as an ink for a hole injection / transport layer, in addition to the above essential components, the positive voltage described later is used from the viewpoint of further reducing the drive voltage of the hole injection / transport layer and further improving the device life. A compound that can be dissolved in a hydrophilic solvent may be appropriately selected and contained from the pore transporting compounds.

In the transition metal compound-containing nanoparticle-dispersed ink of the present invention, when the hole transporting compound is used, the content of the hole transporting compound is 10 with respect to 100 parts by mass of the transition metal-containing nanoparticle. It is preferable that it is -10000 mass parts from the point which improves hole injection transport property, and the stability of a film | membrane is high and a long lifetime is achieved.
In the hole injecting and transporting layer, when the content of the hole transporting compound is too small, it is difficult to obtain a synergistic effect obtained by mixing the hole transporting compound. On the other hand, when there is too much content of the said hole transportable compound, the effect using a transition metal containing nanoparticle will become difficult to be acquired.

The transition metal compound-containing nanoparticle-dispersed ink of the present invention may contain additives such as a binder resin, a curable resin, and a coating property improving agent as long as the effects of the present invention are not impaired.
Examples of the binder resin include polycarbonate, polystyrene, polyarylate, and polyester. Moreover, you may contain the binder resin hardened | cured with a heat | fever or light. As a material that is cured by heat or light, a material in which a curable functional group is introduced into the molecule in the hole transporting compound, a curable resin, or the like can be used. Specifically, examples of the curable functional group include acrylic functional groups such as acryloyl group and methacryloyl group, vinylene group, epoxy group, and isocyanate group.
The curable resin may be a thermosetting resin or a photocurable resin, and examples thereof include an epoxy resin, a phenol resin, a melamine resin, a polyester resin, a polyurethane resin, a silicon resin, and a silane coupling agent. be able to.

(Method for producing transition metal compound-containing nanoparticle-dispersed ink)
Transition metal compound-containing nanoparticle-dispersed ink is usually in a hydrophilic solvent, in the first transition metal compound-containing nanoparticle-dispersed ink, in nanoparticles, in the second transition metal compound-containing nanoparticle-dispersed ink, in transition metal carbide In addition to essential components such as one or more compounds (U) selected from the group consisting of transition metal nitrides and transition metal sulfides, protective agents having organic groups including linking groups and hydrophilic groups, hole transport It is prepared by mixing and dispersing an optional component such as a chemical compound according to a general preparation method. A paint shaker or a bead mill can be used for mixing and dispersing.

  As the second method for producing the first transition metal compound-containing nanoparticle-dispersed ink according to the present invention, the transition metal compound-containing nanoparticles can be obtained in one pot without filtering out or purifying the transition metal compound-containing nanoparticles. A method for producing a dispersed ink. A second production method of such a transition metal compound-containing nanoparticle-dispersed ink includes a transition metal complex containing any atom of carbon, nitrogen or sulfur, a protective agent having an organic group containing a linking group and a hydrophilic group, And a solution containing a hydrophilic solvent having a boiling point of 160 to 260 ° C. is heated at 150 to 250 ° C.

As the transition metal complex containing any atom of carbon, nitrogen or sulfur, a transition metal complex containing any atom of carbon, nitrogen or sulfur may be used as the ligand. The thing similar to what was demonstrated in the manufacturing method of particle | grains can be used.
Moreover, since the protective agent which has an organic group containing a coupling group and a hydrophilic group is the same as that of the above-mentioned nanoparticle, description here is abbreviate | omitted.

  A hydrophilic solvent having a boiling point of 160 to 260 ° C. can be used as it is as an ink solvent because it is relatively easy to apply and dry. Examples of the hydrophilic solvent having a boiling point of 160 to 260 ° C. include ethylene glycol, propylene glycol, methyl diglycol, butyl glycol, isobutyl glycol, methyl propylene diglycol, butyl propylene glycol, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether, and diethylene glycol. Examples include dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, ethylene glycol monobutyl ether, and diacetone alcohol.

  A step of carbonizing a solution containing a transition metal complex, a protective agent having an organic group containing a linking group and a hydrophilic group, and a hydrophilic solvent having a boiling point of 160 to 260 ° C. at 150 to 250 ° C .; And a step of protecting with a protective agent. The step of carbonizing and the step of protecting with a protective agent are preferably performed in an argon gas atmosphere from the viewpoint of maintaining dispersion stability in the reaction solution. The heating temperature is preferably within the above temperature range and at a temperature lower by at least 10 ° C. than the boiling point of the hydrophilic solvent. It is preferable to perform the carbonizing step under an argon gas atmosphere and the step of protecting with a protective agent, and then change to an air atmosphere and perform the oxidizing step.

(device)
A device according to the present invention is a device having two or more electrodes opposed to each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes,
The hole injecting and transporting layer contains at least the transition metal compound-containing nanoparticles according to the present invention.

  In the device of the present invention, the hole injecting and transporting layer contains the nanoparticles according to the present invention, so that the hole injecting characteristics are improved by the characteristics of the contained transition metal compound, and the stability and uniformity over time are improved. Since the film has a high property, the lifetime of the element can be extended.

As described above, the nanoparticles used in the device of the present invention can improve the lifetime because of the reaction of transition metal compounds such as transition metal carbide oxide, transition metal nitride oxide and transition metal sulfide oxide contained in the nanoparticles. This is presumed to be due to the fact that a charge transfer complex is easily formed between the nanoparticles and the hole transporting compound when the nanoparticles are contained or the hole transporting compound is contained.
The formation of a charge transfer complex means that, for example, by ¹ H NMR measurement, when nanoparticles are mixed into a solution of a charge transporting compound, an aromatic ring observed in the vicinity of 6 to 10 ppm of the charge transporting compound. This is suggested by the observation of a phenomenon in which the shape and chemical shift value of the proton signal derived from is changed compared to before mixing the nanoparticles.

In addition, since the nanoparticles according to the present invention have very high dispersion stability in a solvent, a nanometer-order thin film having high temporal stability and high uniformity can be formed. Since the thin film is hydrophilic, even if an organic layer is formed adjacently on the thin film by a solution coating method using a hydrophobic solvent, the thin film is a highly stable film without being redissolved. . Conversely, on the organic layer formed by the solution coating method using a hydrophobic solvent, adjacently formed by the solution coating method using the hydrophilic solvent in which the nanoparticles of the present invention are dispersed. However, the organic layer can form a highly stable thin film without being redissolved. Therefore, there is no risk of in-plane characteristic variations or device short-circuiting on the surface of the hole-injecting and transporting layer, and charge transfer is performed uniformly and sufficiently, and hole injection containing nanoparticles according to the present invention is performed. It is speculated that the device of the present invention provided with a transport layer can realize a device with low voltage driving, high power efficiency, and particularly improved lifetime.
In the device of the present invention, by selecting the type of the nanoparticle protective agent, it is easy to make it multifunctional, for example, by imparting functionality such as charge transportability or adhesion.

Thus, unlike the case of using a transition metal oxide of an inorganic compound, the device of the present invention has a very high dispersion stability in a solvent. Can be formed, the manufacturing process is easy.
In the device of the present invention, the hole injecting and transporting layer can be formed by a solution coating method. Therefore, the hole injecting and transporting layer to the light emitting layer can be sequentially formed only on the substrate having a liquid repellent bank only by the coating process. Therefore, after depositing the hole injection layer by high-definition mask vapor deposition or the like as in the case of the transition metal oxide of an inorganic compound, the hole transport layer and the light emitting layer are formed by a solution coating method, and the second electrode is further formed. Compared to a process such as vapor deposition, there is an advantage that a device can be manufactured at a low cost.

Hereinafter, the layer structure of the device according to the present invention will be described.
The device according to the present invention is a device having two or more electrodes facing each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes.
The device according to the present invention includes an organic EL device, an organic transistor, a dye-sensitized solar cell, an organic thin film solar cell, an organic device including an organic semiconductor, a quantum dot light emitting device having a hole injection transport layer, and an oxide. System compound solar cells and the like are also included.
FIG. 3 is a schematic cross-sectional view showing the basic layer structure of the organic device according to the present invention. The basic layer structure of the device of the present invention includes two electrodes (61 and 62) facing each other on the substrate 50, and at least a hole injecting and transporting layer 70 disposed between the two electrodes (61 and 62). It has an organic layer 80.
The substrate 50 is a support for forming each layer constituting the device, and is not necessarily provided on the surface of the electrode 61, and may be provided on the outermost surface of the device.

The hole injecting and transporting layer 70 is a layer that contains at least the above-described nanoparticles and is responsible for injecting and / or transporting holes from the electrode 61 to the organic layer 80.
The organic layer 80 is a layer that exhibits various functions depending on the type of device by being hole-injected and transported, and may be composed of a single layer or a multilayer. When the organic layer is composed of multiple layers, in addition to the hole injecting and transporting layer, the organic layer is further a layer that is the center of the function of the device (hereinafter referred to as a functional layer) or an auxiliary layer for the functional layer. Layers (hereinafter referred to as auxiliary layers). For example, in the case of an organic EL element, a hole transport layer further stacked on the surface of the hole injection transport layer corresponds to the auxiliary layer, and a light emitting layer stacked on the surface of the hole transport layer corresponds to the functional layer. .
The electrode 62 is provided in a place where the organic layer 80 including the hole injecting and transporting layer 70 exists between the opposing electrode 61. Moreover, you may have the 3rd electrode which is not shown in figure as needed. By applying an electric field between these electrodes, the function of the device can be expressed.

FIG. 4 is a schematic cross-sectional view showing an example of a layer configuration of an organic EL element which is an embodiment of the device according to the present invention. In the organic EL device of the present invention, a hole injection / transport layer 70 is laminated on the surface of the electrode 61, and a hole transport layer 90 a as an auxiliary layer and a light emitting layer 100 as a functional layer are laminated on the surface of the hole injection / transport layer 70. Has the form. Thus, when the hole injection / transport layer characteristic of the present invention is used at the position of the hole injection layer, in addition to improving the conductivity, the hole injection / transport layer forms a charge transfer complex to form a solution. Since it becomes insoluble in the solvent used in the coating method, it is possible to apply the solution coating method also when laminating the upper hole transport layer. Furthermore, improvement in adhesion to the electrode can be expected.
FIG. 5 is a schematic cross-sectional view showing another example of the layer configuration of the organic EL element which is an embodiment of the device according to the present invention. In the organic EL device of the present invention, a hole injection layer 90b is formed as an auxiliary layer on the surface of the electrode 61, a hole injection transport layer 70 is stacked on the surface of the hole injection layer 90b, and a light emitting layer 100 is stacked as a functional layer. Have different forms. As described above, when the hole injection / transport layer characteristic of the present invention is used at the position of the hole transport layer, in addition to the improvement in conductivity, the hole injection / transport layer forms a charge transfer complex to form a solution. Since it becomes insoluble in the solvent used in the coating method, the solution coating method can be applied also when the upper light-emitting layer is laminated.
FIG. 6 is a schematic cross-sectional view showing another example of the layer configuration of the organic EL element which is an embodiment of the device according to the present invention. The organic EL device of the present invention has a configuration in which a hole injection transport layer 70 and a light emitting layer 100 as a functional layer are sequentially stacked on the surface of an electrode 61. Thus, when the hole injection / transport layer characteristic of the present invention is used as a single layer, there is a process advantage that the number of steps is reduced.
4 to 6, each of the hole injection transport layer 70, the hole transport layer 90a, and the hole injection layer 90b may be composed of a plurality of layers instead of a single layer. .

4 to 6, the electrode 61 functions as an anode and the electrode 62 functions as a cathode. In the organic EL element, when an electric field is applied between the anode and the cathode, holes are injected from the anode into the light emitting layer 100 through the hole injection transport layer 70 and the hole transport layer 90a, and electrons are injected into the cathode. By being injected into the light emitting layer, the holes and electrons injected inside the light emitting layer 100 are recombined to emit light outside the device.
In order to emit light to the outside of the element, all the layers existing on at least one surface of the light emitting layer need to be transparent to light having at least a part of wavelengths in the visible wavelength range. Although not shown, an electron transport layer and / or an electron injection layer may be provided between the light emitting layer and the electrode 62 (cathode) as necessary.

FIG. 7 is a schematic cross-sectional view showing an example of a layer configuration of an organic transistor which is another embodiment of the device according to the present invention. The organic transistor is disposed on the substrate 50 between the electrode 63 (gate electrode), the opposing electrode 61 (source electrode) and electrode 62 (drain electrode), and the electrode 63, electrode 61, and electrode 62. An organic semiconductor layer 110 as an organic layer, an insulating layer 120 interposed between the electrode 63 and the electrode 61, and between the electrode 63 and the electrode 61, and a hole injection transport layer on the surface of the electrode 61 and the electrode 62 70 is formed.
The organic transistor has a function of controlling a current between the source electrode and the drain electrode by controlling charge accumulation in the gate electrode.

  FIG. 8 is a schematic cross-sectional view showing an example of another layer configuration of an organic transistor which is an embodiment of the device according to the present invention. The organic transistor is disposed on the substrate 50 between the electrode 63 (gate electrode), the opposing electrode 61 (source electrode) and electrode 62 (drain electrode), and the electrode 63, electrode 61, and electrode 62. The hole injecting and transporting layer 70 of the present invention is formed as the organic layer to form the organic semiconductor layer 110, and the insulating layer 120 is interposed between the electrode 63 and the electrode 61 and between the electrode 63 and the electrode 62. In this example, the hole injection transport layer 70 is the organic semiconductor layer 110.

  In the device of the present invention, the hole injecting and transporting layer contains the nanoparticles according to the present invention and can be dispersed in a hydrophilic solvent, and the formed hole injecting and transporting layer becomes hydrophilic. Even if the organic layer is formed adjacently by a solution coating method using a hydrophobic solvent, the thin film becomes a stable film without being redissolved. Therefore, the device of the present invention is suitable for an embodiment containing a charge transport layer containing a charge transport compound which can be dissolved and / or dispersed in a hydrophobic solvent adjacent to the hole injection transport layer.

The layer structure of the device of the present invention is not limited to the above-described examples, and has substantially the same structure as the technical idea described in the claims of the present invention, and has the same functions and effects. Anything that exhibits is included in the technical scope of the present invention.
Hereinafter, each layer of the device according to the present invention will be described in detail.

(Hole injection transport layer)
The device of the present invention includes at least a hole injection transport layer. When the device of the present invention is an organic device and the organic layer is a multilayer, the organic layer further assists the layer serving as the center of the function of the device and the functional layer in addition to the hole injecting and transporting layer. Although the auxiliary layer which plays a role is included, those functional layers and auxiliary layers will be described in detail in specific examples of the device described later.

  The hole injecting and transporting layer in the device of the present invention contains at least the nanoparticles according to the present invention, and is preferably formed using the transition metal compound-containing nanoparticle-dispersed ink. The hole injecting and transporting layer in the device of the present invention includes not only a continuous layer that completely covers the lower surface, but also a discontinuous layer formed in dotted islands, nets, or the like.

  The hole injecting and transporting layer in the device of the present invention may be composed only of nanoparticles, but may further contain other components. Among them, it is preferable to contain a hole transporting compound from the viewpoint of further reducing the driving voltage and improving the device life.

  In the case of containing a hole transporting compound, the hole injecting and transporting layer in the device of the present invention may be composed of one mixed layer containing nanoparticles and a hole transporting compound, or the mixture It may consist of a plurality of layers including layers. The hole injecting and transporting layer may be composed of a plurality of layers in which a layer containing nanoparticles and a layer containing a hole transporting compound are laminated at least. The hole injecting and transporting layer may be a layer in which a layer containing nanoparticles and a layer containing at least nanoparticles and a hole transporting compound are laminated.

  The hole injection transport layer of the present invention may contain two or more kinds of transition metal compound-containing nanoparticles. For example, two or more kinds of transition metal compound-containing nanoparticles having different transition metals and / or transition metal compounds may be contained. In this case, by using nanoparticles with different work functions (HOMO) and allowing holes to move stepwise via two types of nanoparticles, the energy barrier between adjacent layers can be further reduced, The inclusion of nanoparticles specialized for hole injecting properties and nanoparticles specialized for hole transporting properties has the advantage that hole injecting and transporting properties exceeding the function of single particles can be obtained. Moreover, you may contain the 2 or more types of transition metal compound containing nanoparticle from which each contained protective agent differs. In this case, the hole injection / transport layer can be multi-functionalized by selecting a plurality of types of protective agents, for example, with nanoparticles protected with a highly liquid repellent protective agent and a protective agent with a high hole transporting property. By including protected nanoparticles, there is an advantage that a hole injection transport layer having two functions of high liquid repellency and high hole transportability can be formed. Furthermore, the transition metal and / or transition metal compound contained, and two or more kinds of transition metal compound-containing nanoparticles with different protective agents may be contained.

The hole transporting compound can be appropriately used as long as it has a hole transporting property. Here, the hole transportability means that an overcurrent due to hole transport is observed by a known photocurrent method.
As the hole transporting compound, in addition to a low molecular compound, a high molecular compound is also preferably used. The hole transporting polymer compound refers to a polymer compound having a hole transporting property and having a weight average molecular weight of 2000 or more according to polystyrene conversion value of gel permeation chromatography (GPC).

The hole transporting compound is not particularly limited, and examples thereof include arylamine derivatives, anthracene derivatives, carbazole derivatives, thiophene derivatives, fluorene derivatives, distyrylbenzene derivatives, and spiro compounds.
Examples of arylamine derivatives include N, N′-bis- (3-methylphenyl) -N, N′-bis- (phenyl) -benzidine (TPD), bis (N- (1-naphthyl-N-phenyl). ) Benzidine) (α-NPD), 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (MTDATA) and 4,4 ′, 4 ″ -tris (N- (2-naphthyl)) -N-phenylamino) triphenylamine (2-TNATA) and the like.
Examples of the carbazole derivative include 4,4-N, N′-dicarbazole-biphenyl (CBP).
Examples of the fluorene derivative include N, N′-bis (3-methylphenyl) -N, N′-bis (phenyl) -9,9-dimethylfluorene (DMFL-TPD).
Examples of the distyrylbenzene derivative include 4- (di-p-tolylamino) -4 ′-[(di-p-tolylamino) styryl] stilbene (DPAVB) and the like.
Examples of the spiro compound include 2,7-bis (N-naphthalen-1-yl-N-phenylamino) -9,9-spirobifluorene (Spiro-NPB) and 2,2 ′, 7,7′-. And tetrakis (N, N-diphenylamino) -9,9′-spirobifluorene (Spiro-TAD).

Examples of the hole transporting polymer compound include a polymer containing an arylamine derivative, anthracene derivative, carbazole derivative, thiophene derivative, fluorene derivative, distyrylbenzene derivative or spiro compound in a repeating unit. .
Specific examples of the polymer containing an arylamine derivative as a repeating unit include, as a non-conjugated polymer, copoly [3,3′-hydroxy-tetraphenylbenzidine / diethylene glycol] carbonate (PC-TPD-DEG), the following structure Poly [N, N′-bis (4-butylphenyl) -N, N′-bis (phenyl) -benzidine] can be given as a conjugated polymer such as PTPDES and Et-PTPDK represented by

Specific examples of the polymer containing anthracene derivatives in the repeating unit include poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (9,10-anthracene)]. it can.
Specific examples of the polymer containing carbazoles in the repeating unit include polyvinyl carbazole (PVK).
Specific examples of the polymer containing thiophene derivatives in the repeating unit include poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (bithiophene)].

As a specific example of a polymer containing a fluorene derivative as a repeating unit, poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (4,4′-) represented by the following formula (1): (N- (4-sec-butylphenyl)) diphenylamine)] (TFB), poly [(9,9-dioctylfluorenyl-2,7-diyl) -alt-co- represented by the following formula (2) (N, N′-bis {4-butylphenyl} -benzidine N, N ′-{1,4-diphenylene})], poly [(9,9-dioctylfluorenyl-) represented by the following formula (3) 2,7-diyl)] (PFO) and the like.
Specific examples of the polymer containing a spiro compound as a repeating unit include poly [(9,9-dioctylfluorenyl-2,7-diyl) -alt-co- (9,9′-spiro-bifluorene-2, 7-diyl)] and the like.
These hole transporting polymer compounds may be used alone or in combination of two or more.

The average film thickness of the hole injecting and transporting layer can be appropriately determined depending on the purpose and the adjacent layer, but is usually 0.1 to 1000 nm, preferably 1 to 500 nm.
In addition, the film thickness in the case of having a discontinuous layer such as an island shape is defined as a film thickness obtained by averaging the whole, for example, by measuring the entire film including the discontinuous layer with an ellipsometer A value can be obtained.
The work function of the hole injecting and transporting layer is preferably 5.0 to 6.0 eV, and more preferably 5.0 to 5.8 eV from the viewpoint of hole injecting efficiency.

The hole injection transport layer of the present invention can be formed by a solution coating method. The hole injecting and transporting layer of the present invention is formed by a solution coating method, and the manufacturing process is easy and the yield is high because a short circuit hardly occurs, and a long life is achieved by forming a charge transfer complex. To preferred. In this case, the hole injecting and transporting layer of the present invention is formed by a solution coating method using a solution (transition metal compound-containing nanoparticle dispersed ink) dispersed in a solvent in which at least nanoparticles are well dispersed. In addition, when forming a hole injecting and transporting layer containing a hole transporting compound, a solution in which nanoparticles and a hole transporting compound are mixed in a hydrophilic solvent in which both are well dissolved or dispersed is used. Alternatively, it may be formed by a solution coating method. In this case, when mixed in a hydrophilic solvent in which both the nanoparticles and the hole transporting compound are well dissolved or dispersed, the nanoparticles and the hole transporting compound interact in the solution to form a charge transfer complex. Therefore, it is possible to form a hole injecting and transporting layer having excellent hole transporting properties and stability over time of the film.
The hole injecting and transporting layer may be a layer obtained by laminating a layer containing a hole transporting compound on a layer containing nanoparticles by a solution coating method. The hole injecting and transporting layer may be a layer in which a layer containing at least nanoparticles and a hole transporting compound is laminated on a layer containing nanoparticles by a solution coating method.
The solution coating method will be described in the item of the device manufacturing method below.

(substrate)
The substrate serves as a support for the device of the present invention. For example, the substrate may be a flexible material or a hard material. Specific examples of materials that can be used include glass, quartz, polyethylene, polypropylene, polyethylene terephthalate, polymethacrylate, polymethyl methacrylate, polymethyl acrylate, polyester, and polycarbonate.
Among these, when using a synthetic resin substrate, it is desirable to have a gas barrier property. Although the thickness of a board | substrate is not specifically limited, Usually, it is about 0.5-2.0 mm.

(electrode)
The device of the present invention has two or more opposing electrodes on a substrate.
In the device of the present invention, the electrode is preferably formed of a metal or a metal oxide, and a known material can be appropriately employed. Usually, it can be formed of metals such as aluminum, gold, silver, nickel, palladium and platinum and metal oxides such as oxides of indium and / or tin.

Usually, the electrode is often formed on the substrate by a method such as a sputtering method or a vacuum deposition method, but can also be formed by a wet method such as a coating method or a dipping method. The thickness of the electrode varies depending on the transparency required for each electrode. When transparency is required, the light transmittance in the visible wavelength region of the electrode is usually 60% or more, preferably 80% or more. In this case, the thickness is usually 10 to 1000 nm, Preferably, it is about 20 to 500 nm.
In the present invention, a metal layer may be further provided on the electrode in order to improve the adhesion stability with the charge injection material. The metal layer refers to a layer containing a metal, and is formed from a metal or metal oxide used for the above-described normal electrode.

(Other)
The device of the present invention may have a conventionally known electron injection layer and / or electron transport layer between the electron injection electrode and the organic layer, if necessary.

(Organic EL device)
As one embodiment of the device of the present invention, an organic EL element containing an organic layer including at least the hole injection transport layer and the light emitting layer of the present invention can be mentioned.
Hereinafter, each layer which comprises an organic EL element is demonstrated in order using FIGS.

(substrate)
The substrate 50 serves as a support for the organic EL element, and may be a flexible material or a hard material, for example. Specifically, for example, those described in the description of the substrate of the device can be used.
When light emitted from the light emitting layer 100 is extracted through the substrate 50 side, at least the substrate 50 needs to be made of a transparent material.

(Anode, cathode)
The electrode 61 and the electrode 62 differ depending on the direction in which light emitted from the light emitting layer 100 is extracted, and the electrode 61 and the electrode 62 are transparent. It is necessary to form the electrode 62 from a transparent material when it is necessary to form the electrode 62 from the electrode 62 side.
The electrode 61 provided on the light emitting layer side of the substrate 50 acts as an anode for injecting holes into the light emitting layer, and the electrode 62 provided on the light emitting layer side of the substrate 50 injects electrons into the light emitting layer 100. Acting as a cathode.
In the present invention, the anode and the cathode are preferably formed of the metals or metal oxides listed in the description of the electrode of the device.

(Hole injection transport layer, hole transport layer and hole injection layer)
The hole injection transport layer 70, the hole transport layer 90a, and the hole injection layer 90b are appropriately formed between the light emitting layer 100 and the electrode 61 (anode) as shown in FIGS. As shown in FIG. 4, the hole transport layer 90a may be laminated on the hole injection transport layer 70 according to the present invention, and the light emitting layer 100 may be laminated thereon, or as shown in FIG. The hole injecting and transporting layer 70 according to the present invention may be laminated on the injection layer 90b, and the light emitting layer 100 may be laminated thereon. As shown in FIG. The hole injection transport layer 70 may be stacked, and the light emitting layer 100 may be stacked thereon.

As shown in FIG. 4, when the hole transport layer 90a is laminated on the hole injection transport layer 70 according to the present invention, the hole transport material used for the hole transport layer 90a is not particularly limited. It is preferable to use the hole transporting compound described in the hole injecting and transporting layer according to the present invention. Among them, the same compound as the hole transporting compound used in the adjacent hole injecting and transporting layer 70 according to the present invention improves the adhesion stability of the interface between the hole injecting and transporting layer and the hole transporting layer. Therefore, it is preferable because it contributes to a longer driving life.
The hole transport layer 90a can be formed using a hole transport material in the same manner as the light emitting layer described later. The thickness of the hole transport layer 90a is usually 0.1 to 1 μm, preferably 1 to 500 nm.

As shown in FIG. 5, when the hole injection transport layer 70 according to the present invention is laminated on the hole injection layer 90b, the hole injection material used for the hole injection layer 90b is not particularly limited, and is conventionally known. These compounds can be used. Examples thereof include phenylamine, starburst amine, phthalocyanine, vanadium oxide, molybdenum oxide, ruthenium oxide, oxides such as aluminum oxide, amorphous carbon, polyaniline, and polythiophene derivatives.
The hole injection layer 90b can be formed using a hole injection material in the same manner as the light emitting layer 100 described later. The thickness of the hole injection layer 90b is usually 1 nm to 1 μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

  Further, in consideration of hole injection characteristics, a hole injection material and a hole transport material in which the work function (HOMO) value of each layer increases stepwise from the electrode 61 side toward the light emitting layer 100 that is an organic layer. It is preferable that the hole injection energy barrier at each interface be made as small as possible to complement the large hole injection energy barrier between the electrode 61 and the light emitting layer 100.

Specifically, for example, when ITO (work function immediately after UV ozone cleaning is 5.0 eV) is used for the electrode 61 and Alq3 (HOMO 5.7 eV) is used for the light emitting layer 100, the material constituting the hole injection transport layer 70 TFB (work function 5.4 eV) and nanoparticles having a work function of 5.0 to less than 5.4 eV are selected and stacked in this order, and the work function value of each layer from the electrode 61 side toward the light emitting layer 100 is It is preferable to arrange the layers so as to increase in order. In addition, the value of the said work function or HOMO was quoted from the measured value of the photoelectron spectroscopy which used photoelectron spectrometer AC-1 (made by Riken Keiki Co., Ltd.).
In the case of such a layer structure, a large energy barrier of hole injection between the electrode 61 (work function 5.0 eV immediately after UV ozone cleaning) and the light emitting layer 100 (for example, HOMO 5.7 eV), the HOMO value is stepped. As a result, a hole injection / transport layer having excellent hole injection efficiency and excellent hole injection efficiency can be obtained.

(Light emitting layer)
As shown in FIGS. 4 to 6, the light emitting layer 100 is formed of a light emitting material between the substrate 50 on which the electrode 61 is formed and the electrode 62.
The material used for the light emitting layer of the present invention is not particularly limited as long as it is a material usually used as a light emitting material, and either a fluorescent material or a phosphorescent material can be used. Specifically, materials such as a dye-based light emitting material and a metal complex-based light emitting material can be given, and either a low molecular compound or a high molecular compound can be used.

Examples of the dye-based luminescent material include arylamine derivatives, anthracene derivatives, (phenylanthracene derivatives), oxadiazole derivatives, oxazole derivatives, oligothiophene derivatives, carbazole derivatives, cyclopentadiene derivatives, silole derivatives, distyrylbenzene derivatives, Distyrylpyrazine derivatives, distyrylarylene derivatives, silole derivatives, stilbene derivatives, spiro compounds, thiophene ring compounds, tetraphenylbutadiene derivatives, triazole derivatives, triphenylamine derivatives, trifumanylamine derivatives, pyrazoloquinoline derivatives, hydrazone derivatives, pyras Examples include zoline dimer, pyridine ring compound, fluorene derivative, phenanthroline, perinone derivative, perylene derivative and the like. These dimers, trimers, oligomers, and compounds of two or more derivatives can also be used.
These materials may be used alone or in combination of two or more.

Examples of the metal complex-based light emitting material include an aluminum quinolinol complex, a benzoquinolinol beryllium complex, a benzoxazole zinc complex, a benzothiazole zinc complex, an azomethylzinc complex, a porphyrin zinc complex, a europium complex, and the central metal such as Al, Zn, Be. Or a metal complex having a rare earth metal such as Tb, Eu, or Dy and having a oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure, or the like as a ligand.
These materials may be used alone or in combination of two or more.

As the high molecular weight light emitting material, a material obtained by introducing the above low molecular weight material into the molecule as a straight chain, a side chain or a functional group, a polymer, a dendrimer, or the like can be used.
Examples thereof include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyvinyl carbazole, polyfluorenone derivatives, polyfluorene derivatives, polyquinoxaline derivatives, and copolymers thereof.

A doping material may be added to the light emitting layer for the purpose of improving the light emission efficiency or changing the light emission wavelength. In the case of a polymer material, these may be included as a light emitting group in the molecular structure. Examples of such doping materials include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacudrine derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazoline derivatives, decacyclene, phenoxazone, quinoxaline derivatives, carbazole derivatives, and fluorene derivatives. Can be mentioned. Moreover, the compound which introduce | transduced the spiro group into these can also be used.
These materials may be used alone or in combination of two or more.

  In the present invention, as the material of the light emitting layer, any of a low molecular compound or a high molecular compound that emits fluorescence or a low molecular compound or a high molecular compound that emits phosphorescence can be used. In the present invention, when the base layer on which the light emitting layer is provided is the hole injection transport layer of the present invention, the hole injection transport layer forms a charge transfer complex and is a hydrophobic solvent such as xylene used in the solution coating method. As a material for the light emitting layer, it is possible to use a polymer material that is easily dissolved in a hydrophobic solvent such as xylene and forms a layer by a solution coating method. In this case, a high molecular compound containing a fluorescent compound or a low molecular compound that emits fluorescence, or a high molecular compound containing a phosphor compound or a low molecular compound that emits phosphor can be preferably used.

The light emitting layer can be formed using a light emitting material by a solution coating method, a vapor deposition method, or a transfer method. As the solution coating method, the same method as described in the item of the device manufacturing method described later can be used. For example, in the case of the vacuum deposition method, the vapor deposition method is performed by putting the material of the light emitting layer in a crucible installed in a vacuum vessel, and evacuating the vacuum vessel to about 10 ⁻⁴ Pa with an appropriate vacuum pump. The crucible is heated to evaporate the material of the light emitting layer, and the light emitting layer 100 is formed on the laminate of the substrate 50, the electrode 61, the hole injection transport layer 70, and the hole transport layer 90a placed facing the crucible. Let it form. In the transfer method, for example, a light emitting layer previously formed on a film by a solution coating method or a vapor deposition method is bonded to a hole injecting and transporting layer 70 provided on an electrode, and the light emitting layer 100 is heated to form the hole injecting and transporting layer 70. It is formed by transferring it upward. Alternatively, the hole injecting and transporting layer side of the laminate in which the film, the light emitting layer 100, and the hole injecting and transporting layer 70 are laminated in this order may be transferred onto the electrode.
The film thickness of the light emitting layer is usually about 1 to 500 nm, preferably about 20 to 1000 nm. In the present invention, since it is preferable to form the hole injection transport layer by a solution coating method, there is an advantage that the process cost can be reduced when the light emitting layer is also formed by a solution coating method.

(Organic transistor)
Another embodiment of the device according to the present invention is an organic transistor. Hereinafter, each layer which comprises an organic transistor is demonstrated using FIG.7 and FIG.8.
Since the hole injecting and transporting layer 70 is formed on the surfaces of the electrode 61 (source electrode) and the electrode 62 (drain electrode), the organic transistor of the present invention as shown in FIG. And the hole injection / transport layer of the present invention has high film stability, which contributes to a longer driving life.
In the organic transistor of the present invention, the hole injection transport layer 70 of the present invention may function as the organic semiconductor layer 110 as shown in FIG.
Further, in the organic transistor of the present invention, as shown in FIG. 7, a hole injecting and transporting layer 70 is formed on the surfaces of the electrode 61 (source electrode) and the electrode 62 (drain electrode), and the organic semiconductor layer 110 is formed on the electrode surface. You may form the hole injection transport layer 70 of this invention in which material differs from the formed hole injection transport layer.

When an organic transistor as shown in FIG. 7 is formed, a donor (p-type) low-molecular or high-molecular organic semiconductor material can be used as a material for forming the organic semiconductor layer.
Examples of the organic semiconductor materials include porphyrin derivatives, arylamine derivatives, polyacene derivatives, perylene derivatives, rubrene derivatives, coronene derivatives, perylenetetracarboxylic acid diimide derivatives, perylenetetracarboxylic acid dianhydride derivatives, polythiophene derivatives, polyparaphenylene derivatives, Polyparaphenylene vinylene derivatives, polypyrrole derivatives, polyaniline derivatives, polyfluorene derivatives, polythiophene vinylene derivatives, polythiophene-heterocyclic aromatic copolymers and derivatives thereof, α-6-thiophene, α-4-thiophene, oligoacene derivatives of naphthalene, Oligothiophene derivatives of α-5-thiophene, pyromellitic dianhydride derivatives and pyromellitic acid diimide derivatives can be used.
Examples of porphyrin derivatives include metal phthalocyanines such as phthalocyanine and copper phthalocyanine.
As the arylamine derivative, for example, m-TDATA can be used.
Examples of polyacene derivatives include naphthalene, anthracene, naphthacene, and pentacene.
In addition, a layer having a higher conductivity by mixing such porphyrin derivatives and triphenylamine derivatives with inorganic acids such as Lewis acid, tetracyanoquinodimethane (F ₄ -TCNQ), vanadium and molybdenum. It can also be used.

  Even in the case of forming an organic transistor including the hole injecting and transporting layer of the present invention as shown in FIG. 7, the compound constituting the organic semiconductor layer 110 may be the hole injecting and transporting layer of the present invention. The use of a hole-transporting compound, particularly a hole-transporting polymer compound, improves the adhesion stability of the interface between the hole-injecting / transporting layer 70 and the organic semiconductor layer 110 of the present invention, and extends the driving life. It is preferable from the point of contribution.

The carrier mobility of the organic semiconductor layer is preferably 10 ⁻⁶ cm / Vs or more, and particularly preferably 10 ⁻³ cm / Vs or more for an organic transistor from the viewpoint of transistor characteristics.
The organic semiconductor layer can be formed by a solution coating method or a dry process, similarly to the light emitting layer of the organic EL element.

The substrate, gate electrode, source electrode, drain electrode, and insulating layer are not particularly limited, and can be formed using the following materials, for example.
The substrate 50 serves as a support for the device of the present invention, and may be, for example, a flexible material or a hard material. Specifically, the same substrate as that of the organic EL element can be used.
The gate electrode, the source electrode, and the drain electrode are not particularly limited as long as they are conductive materials. From the point of forming the hole injection transport layer 70 using the transition metal compound-containing nanoparticles according to the present invention, a metal is used. Or it is preferable that it is a metal oxide. Specifically, the same metal or metal oxide as the electrode in the organic EL element described above can be used, but platinum, gold, silver, copper, aluminum, indium, ITO, and carbon are particularly preferable.

  Various insulating materials can be used for the insulating layer that insulates the gate electrode, and an inorganic oxide or an organic compound can be used. In particular, an inorganic oxide having a high relative dielectric constant is preferable. Inorganic oxides include silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium zirconate titanate, lead zirconate titanate, lead lanthanum titanate, strontium titanate, Examples thereof include barium titanate, barium magnesium fluoride, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth tantalate niobate, and trioxide yttrium. Among them, silicon oxide, aluminum oxide, tantalum oxide and titanium oxide are preferable. Inorganic nitrides such as silicon nitride and aluminum nitride can also be suitably used.

  Examples of the organic compound include polyimide, polyamide, polyester, polyacrylate, photo-curing polymer of photo radical polymerization, photo cation polymerization, copolymer containing acrylonitrile component, polyvinyl phenol, polyvinyl alcohol, novolac resin, and cyanoethyl pullulan. , Phosphazene compounds including polymer bodies and elastomer bodies, and the like can be used.

  In addition, for other organic devices such as dye-sensitized solar cells, organic thin film solar cells, organic semiconductors, quantum dot light emitting elements having a hole injection / transport layer, oxide-based compound solar cells, etc., a hole injection / transport layer is also used. As long as the hole injecting and transporting layer according to the present invention is used, other configurations are not particularly limited, and may be the same as known configurations as appropriate.

(Device manufacturing method)
A first device manufacturing method according to the present invention is a method for manufacturing a device having two or more electrodes opposed to each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes.
Forming a hole injecting and transporting layer on any of the layers on the electrode using the first transition metal compound-containing nanoparticle-dispersed ink.

A method for producing a second device according to the present invention is a method for producing a device having two or more electrodes facing each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes,
Using the second transition metal compound-containing nanoparticle-dispersed ink, forming a hole injecting and transporting layer on any layer on the electrode; and
A step of oxidizing the compound (U).

  In the device manufacturing method according to the present invention, the hole-injecting and transporting layer containing nanoparticles is formed by the solution coating method using the first or second transition metal compound-containing nanoparticle-dispersed ink as described above. Is done. By using the solution coating method, a vapor deposition apparatus is not required when forming the hole injection transport layer, and coating can be performed without using mask vapor deposition, etc., and productivity is high. A device with high adhesion stability between the interface of the injection transport layer and the interface of the hole injection transport layer and the organic layer can be formed.

  Here, the solution coating method is a method in which the first or second transition metal compound-containing nanoparticle-dispersed ink is coated on an underlying electrode or layer and dried to form a hole injecting and transporting layer.

Examples of the solution coating method include dipping methods, spray coating methods, spin coating methods, blade coating methods, dip coating methods, casting methods, roll coating methods, bar coating methods, die coating methods, and liquid dropping methods such as inkjet methods. It is done.
When it is necessary to obtain a thin hole and / or a smooth hole injecting and transporting layer, a spin coating method is preferably used. In addition, when it is necessary to obtain a pattern of a hole injection / transport layer, a liquid dropping method such as an ink jet method, which can deposit a hole injection / transport layer selectively on a substrate, is preferably used. Moreover, when it is necessary to form a hole injection transport layer with a large area, the dipping method and the dip coating method are preferably used.

  In the second device manufacturing method according to the present invention, one or more compounds selected from the group consisting of transition metal carbide, transition metal nitride, and transition metal sulfide contained in the transition metal compound-containing nanoparticle-dispersed ink By including the step of oxidizing (U), it is possible to form a layer containing a transition metal oxide having no solvent solubility using a solution coating method without using a vapor deposition method. Further, the compound (U) in the hole injecting and transporting layer is made into a corresponding transition metal carbide, transition metal nitride or transition metal sulfide, so that the adjacent organic layer and the hole injecting and transporting layer are applied in solution to each other. It is possible to form a stable film while forming by the method, and to change the hole injection / transport property as appropriate. In addition, it is possible to improve the film strength by including the step of oxidizing.

  In the second device manufacturing method according to the present invention, the step of oxidizing the compound (U) may be performed before the step of forming the hole injection transport layer, or the hole injection transport layer is formed. You may perform after a process. In the step of oxidizing compound (U), examples of the oxidation method include heating means, light irradiation means, and means for causing active oxygen to act in the presence of oxygen, and these may be used in combination as appropriate. The method described in the above-described nanoparticle production method may be the same.

  That is, as one aspect of the second device manufacturing method according to the present invention, the second transition metal compound-containing nanoparticle-dispersed ink is used to form a transition metal carbide or transition metal on any layer on the electrode. A step of forming a hole injecting and transporting layer comprising at least one compound (U) selected from the group consisting of nitrides and transition metal sulfides and a protective agent; and the compound in the hole injecting and transporting layer ( Examples of the production method include a step of oxidizing U) to transition metal carbide oxide, transition metal nitride oxide, or transition metal sulfide oxide, respectively. In this way, a hole injecting and transporting layer containing nanoparticles can be formed.

  As another aspect of the second device manufacturing method according to the present invention, before the step of forming the hole injection transport layer, the transition metal carbide contained in the second transition metal compound-containing nanoparticle dispersed ink, transition A step of oxidizing one or more compounds (U) selected from the group consisting of metal nitrides and transition metal sulfides, and using the compounds (U) as nanoparticles; Using the oxidized transition metal compound-containing nanoparticle-dispersed ink, a hole injection / transport layer containing nanoparticles is formed. After forming the layer, an oxidation step may be further performed.

  Conventionally known processes can be appropriately used for other processes in the device manufacturing method.

  Hereinafter, the present invention will be described more specifically with reference to examples. These descriptions do not limit the present invention. Moreover, the thickness of the layer or film | membrane is represented by the average film thickness.

(Production Example 1)
In the following procedure, a molybdenum oxide-containing nanoparticle ink protected with polyvinylpyrrolidone was synthesized.
In a 50 ml three-necked flask, 0.8 g of molybdenum hexacarbonyl (manufactured by Kanto Chemical Co., Inc.), 0.1 g of polyvinylpyrrolidone (average molecular weight: 10,000, manufactured by SIGMA-ALDRICH), 12.8 g of ethylene glycol (Kanto Chemical) Weighed). The mixture was placed in an argon gas atmosphere and heated to 180 ° C. with stirring, and the temperature was maintained for 2 hours. Thereafter, the mixed liquid was cooled to room temperature (24 ° C.), changed from an argon gas atmosphere to an air atmosphere, and molybdenum carbide oxide-containing nanoparticles protected with polyvinylpyrrolidone were dispersed in a solvent. A product-containing nanoparticle ink was obtained.

(Production Example 2)
In the following procedure, a molybdenum carbide-containing nanoparticle ink protected with thioglycolic acid was prepared.
In a 50 ml three-necked flask, 0.8 g of n-hexadecylamine (manufactured by Kanto Chemical Co., Inc.) and 12.8 g of n-octyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) are weighed and depressurized while stirring. In order to remove volatile components, it was left at room temperature (24 ° C.) for 3.5 hours. The vacuum atmosphere was changed to an atmospheric atmosphere, and 0.8 g of molybdenum hexacarbonyl (manufactured by Kanto Chemical Co., Inc.) was added. The mixture was placed in an argon gas atmosphere, heated to 280 ° C. with stirring, and the temperature was maintained for 1 hour. Then, after cooling this liquid mixture to room temperature (24 degreeC) and changing from argon gas atmosphere to air | atmosphere, ethanol 20g was added, and after separating a deposit from a reaction liquid by centrifugation next, it shows below. Purification by reprecipitation was performed according to the procedure. That is, the precipitate was mixed with 3 g of chloroform to obtain a dispersion, and 6 g of ethanol was added dropwise to the dispersion to obtain a purified precipitate. The reprecipitation liquid thus obtained is centrifuged, and the precipitate is separated from the reaction liquid, and then dried to obtain a purified product of molybdenum carbide nanoparticles protected with black n-hexadecylamine. Got.
Next, 0.1 g of the synthesized n-hexadecylamine-protected molybdenum carbide nanoparticles 0.1 g, 0.8 g of thioglycolic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 20 g of chloroform are weighed in a 50 ml eggplant flask, and the atmosphere The mixture was heated to 50 ° C. with stirring and maintained at that temperature for 2 days. Then, after cooling this liquid mixture to room temperature (24 degreeC), the deposit was isolate | separated from the reaction liquid by centrifugation, and the refinement | purification by reprecipitation was performed in the procedure shown below. That is, the precipitate was mixed with 5 g of 2-propanol to obtain a dispersion, and 12 g of hexane was dropped into this dispersion to obtain a purified precipitate. Next, the reprecipitation liquid was centrifuged, the precipitate was separated from the reaction liquid, and then dried to obtain molybdenum carbide nanoparticles protected with thioglycolic acid. The molybdenum carbide-containing nanoparticles thus obtained were dispersed at a concentration of 0.5% by weight with respect to 2-propanol to obtain a molybdenum carbide-containing nanoparticle ink.

(Test: Crystal structure measurement)
The crystal structure of the molybdenum carbide nanoparticles protected with n-hexadecylamine, which is the intermediate obtained in Production Example 2, was identified by powder X-ray diffraction. RINT-1500 manufactured by Rigaku Co., Ltd. was used as the measurement device, and the measurement sample was prepared by placing a black powder to be measured on glass. A CuKα ray was used as the X-ray source, and the tube voltage was 50 kV and the tube current was 250 mA. The measurement was performed by the 2θ / θ scanning method under the conditions where the scanning speed was 2 ° per minute and the step angle was 0.05 °.
The black powder of molybdenum carbide nanoparticles protected with n-hexadecylamine as an intermediate obtained in Production Example 2 has 2θ = 37.8, 43.7, 63.4, 75.7, A sharp peak at 79.9 ° was observed. Database JCPDS card No. From the value of 15-0457, it was confirmed that the produced black powder was mainly composed of Mo ₂ C.

(Test: valence measurement)
The valence of the molybdenum carbide nanoparticles protected with n-hexadecylamine, which is an intermediate obtained in Production Example 2, was measured by X-ray photoelectron spectroscopy (XPS). For the measurement, ESCA-3400 type manufactured by Kratos was used. As the X-ray source used for the measurement, MgKα ray was used. A monochromator was not used, and measurement was performed under the conditions of an acceleration voltage of 10 kV and a filament current of 20 mA.

  As a measurement sample, a black powder of molybdenum carbide nanoparticles protected with n-hexadecylamine, which is an intermediate obtained in Production Example 2, was dispersed in cyclohexanone at a concentration of 0.4% by mass in the atmosphere. An ink was prepared. The ink was applied with a spinner on a glass substrate with ITO in the atmosphere to form a thin film. The thin film was dried in air at 200 ° C. for 30 minutes. The thickness of the thin film after drying was 10 nm. The film thickness is measured by forming a layer made of the material to be measured as a single layer on a cleaned glass substrate with ITO, creating a step with a cutter knife, and then measuring the height of the step with a probe microscope. Measurement was performed in a tapping mode using Nanopics 1000 manufactured by I Nano Technology.

When the dried thin film was measured by the XPS method, a spectrum attributed to 3d 5/2 of MoO ₃ was observed at a peak position of 232.5 eV. Furthermore, not only MoO ₃ having an oxidation number of Mo of +6 but also a peak estimated to be Mo having an oxidation number of +5 was observed as a shoulder in the vicinity of 231.2 eV.
When this thin film was sputtered with argon gas to remove about 5 nm from the surface, a peak attributed to MoO ₂ with an oxidation number of Mo of +4 was observed, and a peak with an oxidation number of 0 was not observed. . Sputtering was repeated until the underlying ITO glass substrate was seen, but no peak with an oxidation number of Mo of 0 was observed. This XPS result shows that Mo having an oxidation number of +4 that was inside the black powder particles was exposed by sputtering. From this result, it was clarified that Mo having an oxidation number of +4 is present inside the nanoparticles protected with n-hexadecylamine which is the intermediate obtained in Production Example 2.
From the measurement result of crystal structure and the measurement result of XPS, the nanoparticles protected with n-hexadecylamine, which is an intermediate obtained in Production Example 2, are nanoparticles of molybdenum carbide, and the surface layer. The portion is a molybdenum carbide oxide having a valence of +6, and the inside is assumed to have a shell structure that is a molybdenum carbide oxide having a valence of +4 rather than the surface layer.

(Example 1: Production of organic diode)
On the glass substrate, an anode, a layer containing the transition metal compound-containing nanoparticles synthesized in Production Example 1 as a hole injecting and transporting layer, an organic semiconductor layer, and a cathode are formed in this order and laminated to form an organic diode element. Produced.
First, the glass substrate with ITO was subjected to ultrasonic cleaning in the order of water, acetone, and 2-propanol. Subsequently, ITO was patterned by an etching method.
After ITO patterning, UV ozone treatment is performed, and the transition metal compound-containing nanoparticles are formed on the cleaned anode by spin coating using the transition metal compound-containing nanoparticle-containing ink prepared in Production Example 1. A hole injecting and transporting layer was formed. After forming the thin film, it was dried at 200 ° C. for 30 minutes in the air using a hot plate in order to evaporate the solvent and oxidize the transition metal compound sufficiently.
Next, a poly (9,9-dioctylfluorene-bithiophene copolymer) (F8T2) thin film (thickness: 140 nm) which is a conjugated polymer material as an organic semiconductor layer is formed on the prepared hole injecting and transporting layer. Formed.
Next, Al (thickness: 50 nm) was formed as a cathode on the produced organic semiconductor layer. In vacuum (pressure: 5 × 10 ⁻⁴ Pa), a film was formed by resistance heating vapor deposition.

(Example 2: Preparation of organic diode)
Example 1 is the same as Example 1 except that the transition metal compound-containing nanoparticle-containing ink prepared in Production Example 2 was used instead of the transition metal compound-containing nanoparticle-containing ink prepared in Production Example 1. Thus, an organic diode of Example 2 was produced.

(Comparative Example 1: Production of organic diode)
In Example 1, the organic diode of Example 2 was produced in the same manner as Example 1 except that the hole injection transport layer containing the transition metal compound-containing nanoparticles was not formed.

(Evaluation: Hole injection characteristics)
With respect to the organic diodes obtained in Examples 1 and 2 and Comparative Example 1, the hole injection characteristics were evaluated based on the current density when a voltage of 10 V was applied. The evaluation results of the current density are shown in FIG.
The cathode side was negatively biased and the anode side was positively biased.

(Production Example 3)
The molybdenum carbide-containing nanoparticle ink protected with sodium 3-mercapto-1-propanesulfonate was prepared by the following procedure.
(1) Synthesis of molybdenum carbide oxide nanoparticles protected with tri-n-octylphosphine oxide In a 50 ml three-necked flask, 1.3 g of tri-n-octylphosphine oxide (manufactured by Tokyo Chemical Industry Co., Ltd.), n -12.8 g of octyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) was weighed, depressurized while stirring, and allowed to stand at room temperature (24 ° C) for 1.5 hours to remove low volatile components. The vacuum atmosphere was changed to an atmospheric atmosphere, and 0.8 g of molybdenum hexacarbonyl (manufactured by Kanto Chemical Co., Inc.) was added. The mixture was placed in an argon gas atmosphere, heated to 280 ° C. with stirring, and the temperature was maintained for 1 hour. Then, after cooling this liquid mixture to room temperature (24 degreeC) and changing from argon gas atmosphere to air | atmosphere, 20g of methanol was added, and after separating a deposit from a reaction liquid by centrifugation then, it shows below Purification by reprecipitation was performed according to the procedure. That is, the precipitate was mixed with 3 g of chloroform to obtain a dispersion, and 6 g of methanol was added dropwise to the dispersion to obtain a purified precipitate. The reprecipitation liquid thus obtained is centrifuged, and the precipitate is separated from the reaction liquid, and then dried, so that the molybdenum carbide nanoparticles protected with black tri-n-octylphosphine oxide are obtained. A purified product was obtained.

(2) Preparation of molybdenum carbide-containing nanoparticle ink protected with sodium 3-mercapto-1-propanesulfonate Next, a synthesized tri-n-octylphosphine oxide-protected molybdenum carbide in a 50 ml screw tube A solution was prepared by weighing 0.1 g of nanoparticles and 20 g of chloroform. A solution of 0.2 g of sodium 3-mercapto-1-propanesulfonate and 20 g of water was added dropwise to the solution while stirring. This state was maintained for 1 day. Then, it refine | purified in the procedure shown below. That is, 20 g of chloroform was added to the prepared solution and stirred, and the phase of chloroform that was phase-separated after standing was removed to remove tri-n-octylphosphine oxide in the adjusted solution. By repeating this step three times, an aqueous solution of sodium 3-mercapto-1-propanesulfonate purified was obtained. Next, water was removed from the aqueous solution with an evaporator and then dried to obtain molybdenum carbide-containing nanoparticles protected with sodium 3-mercapto-1-propanesulfonate. The molybdenum carbide-containing nanoparticles thus obtained were dispersed at a concentration of 0.5% by weight with respect to water to obtain a molybdenum carbide-containing nanoparticle ink.

(Production Example 4)
In the production of molybdenum carbide-containing nanoparticles in Production Example 3, the same procedure as in Production Example 3 was used, except that sodium 2-mercaptoethanesulfonate was used instead of sodium 3-mercapto-1-propanesulfonate. A molybdenum oxide-containing nanoparticle ink protected with sodium 2-mercaptoethanesulfonate was prepared.

(Production Example 5)
In the production of the molybdenum carbide-containing nanoparticles of Production Example 3, 2-aminoethanesulfonic acid was used instead of sodium 3-mercapto-1-propanesulfonate in the same manner as in Production Example 3, and 2 -A nanoparticle ink containing molybdenum carbide protected with aminoethanesulfonic acid was prepared.

(Production Example 6)
In the production of the molybdenum carbide-containing nanoparticles of Production Example 3, in the same manner as Production Example 3 except that 6-amino-1-hexanol was used instead of sodium 3-mercapto-1-propanesulfonate. , 6-amino-1-hexanol protected molybdenum carbide-containing nanoparticle ink was prepared.

(Production Example 7)
A molybdenum carbide-containing nanoparticle ink protected with 12-amino-1-dodecanol was prepared by the following procedure.
In a 50 ml three-necked flask, 0.1 g of 12-amino-1-dodecanol (manufactured by Tokyo Chemical Industry Co., Ltd.), 12.8 g of 2-methyl-2,4-pentanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) The solution was weighed, decompressed with stirring, and allowed to stand at room temperature (24 ° C.) for 1.5 hours to remove low-volatile components. The vacuum atmosphere was changed to an atmospheric atmosphere, and 0.8 g of molybdenum hexacarbonyl (manufactured by Kanto Chemical Co., Inc.) was added. The mixture was placed in an argon gas atmosphere and heated to 180 ° C. with stirring, and the temperature was maintained for 2 hours. Thereafter, the mixture was cooled to room temperature (24 ° C.), and the molybdenum carbide nanoparticles protected with black 12-amino-1-dodecanol were dissolved in 2-methyl-2,4-pentanediol. A dispersed molybdenum carbide-containing nanoparticle ink was obtained.

(Comparative Production Example 1)
In a 50 mL three-necked flask, 0.8 g of n-hexadecylamine (manufactured by Kanto Chemical Co., Ltd.) and 12.8 g of dioctyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) as a protective agent are weighed and stirred. The pressure was reduced, and the mixture was left at room temperature (24 ° C.) for 1 hour to remove low volatile components. The atmosphere was changed from under vacuum to atmospheric air, and 0.8 g of molybdenum hexacarbonyl (manufactured by Kanto Chemical Co., Inc.) was added. The mixture was placed in an argon gas atmosphere and heated to 280 ° C. with stirring, and the temperature was maintained for 1 hour. Then, after cooling this liquid mixture to room temperature (24 degreeC) and changing from argon gas atmosphere to air | atmosphere, 20g of ethanol was dripped. Subsequently, after separating the precipitate from the reaction solution by centrifugation, purification by reprecipitation was performed according to the procedure shown below.
That is, the precipitate was mixed with 3 g of chloroform to obtain a dispersion, and 6 g of ethanol was added dropwise to the dispersion to obtain a purified precipitate.
The reprecipitation liquid thus obtained was centrifuged, the precipitate was separated from the reaction liquid, and then dried to obtain a black powder of Comparative Production Example 1.

(Comparative Production Example 2) (Preparation of MoO ₃ slurry)
In a paint shaker, 0.3 g of MoO ₃ powder was mixed with 30 g of a toluene solvent and zirconia beads having a diameter of 3 mm, and dispersed in the solvent while physically pulverizing to obtain a toluene dispersion of MoO ₃ . Next, the dispersion was dispersed with zirconia beads having a diameter of 0.3 mm for 48 hours, and the supernatant dispersion was filtered with a 0.2 μm filter to prepare a MoO ₃ slurry.

(Evaluation of solvent dispersibility of nanoparticles)
The nanoparticles obtained in Production Examples 3 to 7 and Comparative Production Example 1 were evaluated for solvent dispersibility. For dispersion in the solvent, 1 mg of nanoparticles was added to 1 mL of the solvent, and ultrasonic waves (frequency: 37 kHz) were irradiated for 1 hour at room temperature (20 ° C.) using an ultrasonic irradiation device (manufactured by SHARP, UT-106). Thereafter, the mixture was allowed to stand at 20 ° C. for 1 hour, and when the dry weight of the precipitate was less than 0.1 mg, it was dispersible. When the dry weight of the precipitate was 0.1 mg or more, it was determined that the precipitate was not dispersible. The obtained results are shown in Table 1.

(Example 3)
A laminate of a transparent anode on a glass substrate, a layer containing molybdenum carbide-containing nanoparticles as a hole injecting and transporting layer and a layer containing a hole transporting compound, and a hole transporting layer, on the glass substrate Then, a light emitting layer, a hole blocking layer, an electron injection layer, and a cathode were formed and laminated in this order, and finally sealed to produce an organic EL device. The work was performed in a nitrogen-substituted glove box having a moisture concentration of 0.1 ppm or less and an oxygen concentration of 0.1 ppm or less except for the transparent anode and the hole injection transport layer.

First, an ITO thin film (thickness: 150 nm) was used as a transparent anode. A glass substrate with ITO (manufactured by Sanyo Vacuum Industry Co., Ltd.) was patterned in a stripe shape. The patterned ITO substrate was ultrasonically cleaned in the order of neutral detergent and ultrapure water, and then subjected to UV ozone treatment. The HOMO of ITO after UV ozone treatment was 5.0 eV.
Next, the molybdenum carbide oxide-containing nanoparticles obtained in Production Example 3 were dissolved in water at a concentration of 0.4% by mass to prepare a hole injection transport layer ink.
Subsequently, the hole injection / transport layer ink was applied on the cleaned anode by a spin coating method to form a hole injection / transport layer containing nanoparticles. After application of the hole injection transport layer ink, it was dried in the atmosphere at 200 ° C. for 30 minutes using a hot plate in order to evaporate the solvent. The thickness of the hole injection transport layer after drying was 10 nm.
Next, an Aldrich polyvinyl carbazole (PVK) thin film (thickness: 10 nm) was applied and formed as a hole transport layer on the prepared hole injection transport layer. The weight average molecular weight of PVK is 1.1 million. A solution in which PVK was dissolved in a solvent of dichloroethane at a concentration of 0.5% by mass was filtered through a 0.2 μm filter and applied by spin coating to form a film. After application of the PVK solution, it was dried at 150 ° C. for 30 minutes using a hot plate in order to evaporate the solvent.
Next, tris [2- (p-tolyl) pyridine)] iridium (III) (Ir (mppy) ₃ ) is contained as a luminescent dopant on the hole transport layer thus formed, A mixed thin film containing 4′-bis (2,2-carbazol-9-yl) biphenyl (CBP) as a host was formed by coating. A solution obtained by dissolving CBP in a solvent of toluene at a concentration of 1% by mass and Ir (mppy) ₃ at a concentration of 0.05% by mass was applied by spin coating to form a film. After application of the ink, it was dried at 100 ° C. for 30 minutes using a hot plate in order to evaporate the solvent.
Next, a bis (2-methyl-8-quinolato) (p-phenylphenolate) aluminum complex (BAlq) thin film was deposited on the light emitting layer as a hole blocking layer. The BAlq thin film was formed in vacuum (pressure: 1 × 10 ⁻⁴ Pa) so as to have a film thickness of 15 nm by a resistance heating method.
Next, a tris (8-quinolinolato) aluminum complex (Alq3) thin film was deposited on the hole blocking layer as an electron transporting layer. The Alq3 thin film was formed in vacuum (pressure: 1 × 10 ⁻⁴ Pa) so as to have a film thickness of 15 nm by a resistance heating method.
Next, on the produced electron transport layer, LiF (thickness: 0.5 nm) as an electron injection layer and Al (thickness: 100 nm) as a cathode were sequentially formed. In vacuum (pressure: 1 × 10 ⁻⁴ Pa), a film was formed by resistance heating vapor deposition.
Finally, after forming the cathode, sealing was carried out in the glove box using non-alkali glass and a UV curable epoxy adhesive to produce an organic EL device of Example 3.

Example 4
In the production of the organic EL device of Example 3, the hole injection / transport layer was carried out except that the hole injection / transport layer was formed using the nanoparticles of Production Example 4 instead of using the nanoparticles of Production Example 3. In the same manner as in Example 3, the organic EL device of Example 4 was produced.

(Example 5)
In the production of the organic EL device of Example 3, the hole injection / transport layer was carried out except that the hole injection / transport layer was formed using the nanoparticles of Production Example 5 instead of using the nanoparticles of Production Example 3. The organic EL device of Example 5 was produced in the same manner as Example 3.

(Example 6)
In the production of the organic EL device of Example 3, the hole injection / transport layer was carried out except that the hole injection / transport layer was formed using the nanoparticles of Production Example 6 instead of using the nanoparticles of Production Example 3. In the same manner as in Example 3, an organic EL device of Example 6 was produced.

(Example 7)
In the production of the organic EL device of Example 3, the hole injection / transport layer was carried out except that the hole injection / transport layer was formed using the nanoparticles of Production Example 7 instead of using the nanoparticles of Production Example 3. In the same manner as in Example 3, the organic EL device of Example 7 was produced.

(Comparative Example 2)
In the production of the organic EL device of Example 3, for the hole injection transport layer, instead of using the nanoparticles of Production Example 3, except that the hole injection transport layer was formed using the nanoparticles of Comparative Production Example 1, In the same manner as in Example 3, an organic EL element of Comparative Example 2 was produced.

(Comparative Example 3)
In the production of the organic EL device of Example 3, for the hole injection / transport layer, instead of using the nanoparticles of Production Example 3, the hole injection / transport layer was coated and formed using the slurry produced in Comparative Production Example 2. Produced the organic EL device of Comparative Example 3 in the same manner as in Example 3. The solid content of the slurry of Comparative Production Example 2 is unknown, but it was about 10 nm when the film thickness was measured after applying the film by spin coating and applying the slurry. After application of the solution, it was dried for 10 minutes at 100 ° C. using a hot plate to evaporate the solvent, but it became slightly cloudy. The fabricated device emitted green light derived from Ir (mppy) ₃ but had many shorts.

The organic EL elements produced in Examples 3 to 7 and Comparative Examples 2 to 3 were driven at 10 mA / cm ² , and the emission luminance and spectrum were measured with a spectroradiometer SR-2 manufactured by Topcon Corporation. The organic EL elements produced in the above examples and comparative examples all emitted green light derived from Ir (mppy) ₃ . The measurement results are shown in Table 2. The current efficiency was calculated from the drive current and the luminance.
The lifetime characteristics of the organic EL element were evaluated by observing the luminance gradually decreasing with time by constant current driving. Here, the time (hours) required for the retention rate to deteriorate to a luminance of 50% with respect to the initial luminance of 1,000 cd / m ² is defined as the lifetime (LT50).

(Summary of results)
When comparing the organic EL element of Example 3 and the organic EL element of Comparative Example 2, the life of the organic EL element of Example 3 is longer than that of Comparative Example 2, and the driving stability is excellent. I understand. By changing the protective agent to sodium 3-mercapto-1-propanesulfonate of Production Example 3 to make it water-dispersible, it becomes insoluble in dichloroethane, and when forming the hole transport layer, the nanoparticles are dissolved by re-dissolution. This is presumably because it was suppressed from flowing out to the hole transport layer, or a decrease in the coverage ratio of ITO due to remelting. It can be seen that it is better to use a hydrophilic protective agent to suppress re-dissolution.
When comparing the organic EL element of Example 3 and the organic EL element of Comparative Example 3, the life of the organic EL element of Example 3 is longer than that of Comparative Example 3, and the driving stability is excellent. I understand. From this result, the ionization potential of molybdenum carbide oxide is more appropriate than the film formed from MoO ₃ slurry, or the affinity / adhesion with organic matter is improved by carbon atoms entering more than a simple oxide. However, it is speculated that it may contribute to the extension of life.
Furthermore, in the organic EL device of Comparative Example 3 using MoO ₃ slurry, the dispersibility of the ink was poor, the hole injection / transport layer tended to aggregate, and the device tended to short-circuit. Also in this dispersibility, it turns out that the molybdenum carbide oxide of this invention is more excellent.
When the device of Example 3 in which the protective agent in the nanoparticles was changed and the devices of Example 4, Example 5, Example 6 and Example 7 were compared, comparable characteristics were obtained.

(Example 8)
An n-octyltrichlorosilane (OTS) treatment was performed on Si / SiO ₂ , and Au was produced as a source-drain electrode by a 30 nm vacuum deposition method. The channel length was 50 μm and the channel width was 1 mm. Subsequently, a hole injection transport layer containing molybdenum carbide oxide was formed using the molybdenum carbide oxide-containing nanoparticle ink prepared in Production Example 2 by an inkjet method. After forming the thin film, it was dried in the atmosphere at 200 ° C. for 30 minutes using a hot plate in order to evaporate the solvent. The molybdenum nanoparticles prepared in Production Example 2 using a hydrophilic solvent could be formed only on the source and drain electrodes without wetting and spreading in the OTS-treated channel portion. Next, a poly (9,9-dioctylfluorene-bithiophene copolymer) (F8T2) thin film (thickness: 50 nm), which is a conjugated polymer material as an organic semiconductor layer, is formed on the prepared hole injecting and transporting layer. The organic thin film transistor was formed.

(Comparative Example 4)
In Example 8, an organic thin film transistor of Comparative Example 4 was produced in the same manner as in Example 8 except that the hole injecting and transporting layer containing molybdenum carbide oxide nanoparticles was not formed.

  As a result of comparing the organic TFT characteristics of the organic thin film transistor (TFT) obtained in Example 8 and Comparative Example 4, a hole injection transport layer using the molybdenum carbide oxide-containing nanoparticles prepared in Production Example 2 was formed. In Example 8, it was confirmed that the On current was increased and the FET mobility was improved.

1 transition metal compound-containing nanoparticles 5 supported carrier 10 transition metal and / or transition metal complex 20 transition metal carbide 30 protective agent 40 transition metal carbide oxide 50 substrate 61, 62, 63 electrode 70 hole injection transport layer 80 organic layer 90a Hole transport layer 90b Hole injection layer 100 Light emitting layer 110 Organic semiconductor layer 120 Insulating layer

Claims (30)

Transition metal carbide oxide, a transition metal compound of one or more selected from the group consisting of transition metal nitride oxide and transition metal sulfide oxide, the protective agent is a coupling having an organic group containing a linking group and a hydrophilic group Connected by a group, dispersible in a hydrophilic solvent,
The hydrophilic group is at least one selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group;
Unlike the hydrophilic group, the linking group is one or more selected from the group consisting of functional groups represented by the following general formulas (1a) to (1o),
The organic group is selected from the group consisting of a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 or more carbon atoms, an aromatic hydrocarbon group, a heterocyclic group, and combinations thereof. characterized in der Rukoto least one transition metal compound-containing nanoparticle.

(In the formula, Z ₁ , Z ₂ and Z ₃ each independently represent a halogen atom or an alkoxy group, and R represents a hydrogen atom or a methyl group.)   The transition metal compound-containing nanoparticles according to claim 1, wherein the transition metal of the transition metal compound is at least one metal selected from the group consisting of molybdenum, tungsten, vanadium and rhenium. The transition metal compound-containing nanoparticle according to claim 1 or 2 , wherein the protective agent is represented by the following general formula [I].
Formula [I]
XYZ
(In the general formula [I], X is a hydrophilic group, Y is a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms and / or an aromatic having 6 to 40 carbon atoms. Represents a group hydrocarbon group, and Z represents a linking group.) The transition metal compound-containing nanoparticle according to any one of claims 1 to 3 , wherein the hydrophilic solvent has a solubility in water (20 ° C) of 50 g / L or more. The transition metal compound-containing nanoparticle according to any one of claims 1 to 4 , wherein the protective agent is a compound having an octanol-water partition coefficient logP of -5 to 2. The hydrophilic group is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfo group, and a sulfonate, and the linking group is an amino group or a thiol group. Item 6. The transition metal compound-containing nanoparticle according to any one of Items 1 to 5 . The transition metal compound-containing nanoparticle according to any one of claims 1 to 6 , which is used for a hole injecting and transporting layer. The transition metal compound-containing nanoparticle according to any one of claims 1 to 6 , which is used for a catalyst. (A) a step of carbonizing the transition metal and / or transition metal complex to form a transition metal carbide,
(B) a step of protecting the transition metal carbide obtained in the step (A) with a protective agent having an organic group containing a linking group; and
(C) a step of oxidizing the transition metal carbide having an organic group obtained in the step (B) to obtain a transition metal carbide oxide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent a protective agent having an organic group containing a sex group, seen including a step of exchanging the protective agent having an organic group containing a hydrophilic group,
The hydrophilic group is at least one selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group;
Unlike the hydrophilic group, the linking group is one or more selected from the group consisting of functional groups represented by the following general formulas (1a) to (1o),
The organic group is selected from the group consisting of a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 or more carbon atoms, an aromatic hydrocarbon group, a heterocyclic group, and combinations thereof. A method for producing a transition metal compound-containing nanoparticle, characterized by comprising at least one kind .

(In the formula, Z ₁ , Z ₂ and Z ₃ each independently represent a halogen atom or an alkoxy group, and R represents a hydrogen atom or a methyl group.) (A) a step of protecting the transition metal and / or the transition metal complex with a protective agent having an organic group containing a linking group;
(B) carbonizing the transition metal or transition metal complex having an organic group obtained in step (a) to form a transition metal carbide having an organic group; and
(C) a step of oxidizing the transition metal carbide having an organic group obtained in the step (b) to form a transition metal carbide oxide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent a protective agent having an organic group containing a sex group, seen including a step of exchanging the protective agent having an organic group containing a hydrophilic group,
The hydrophilic group is at least one selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group;
Unlike the hydrophilic group, the linking group is one or more selected from the group consisting of functional groups represented by the following general formulas (1a) to (1o),
The organic group is selected from the group consisting of a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 or more carbon atoms, an aromatic hydrocarbon group, a heterocyclic group, and combinations thereof. A method for producing a transition metal compound-containing nanoparticle, characterized by comprising at least one kind .

(In the formula, Z ₁ , Z ₂ and Z ₃ each independently represent a halogen atom or an alkoxy group, and R represents a hydrogen atom or a methyl group.) (Α) a step of carbonizing the transition metal and / or transition metal complex to form a transition metal carbide,
(Β) a step of oxidizing the transition metal carbide obtained in the step (α) to form a transition metal carbide oxide, and
(Γ) including the step of protecting the transition metal carbide obtained in the step (β) with a protective agent having an organic group containing a linking group to form a transition metal carbide having an organic group,
The protective agent is a protective agent having an organic group containing a linking group and a hydrophilic group, or the protective agent is a protective agent having an organic group containing a linking group and a hydrophobic group, and the hydrophobic agent a protective agent having an organic group containing a sex group, seen including a step of exchanging the protective agent having an organic group containing a hydrophilic group,
The hydrophilic group is at least one selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a thiol group, a silanol group, a sulfo group, a sulfonate, and an ammonium group;
Unlike the hydrophilic group, the linking group is one or more selected from the group consisting of functional groups represented by the following general formulas (1a) to (1o),
The organic group is selected from the group consisting of a linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 or more carbon atoms, an aromatic hydrocarbon group, a heterocyclic group, and combinations thereof. A method for producing a transition metal compound-containing nanoparticle, characterized by comprising at least one kind .

(In the formula, Z ₁ , Z ₂ and Z ₃ each independently represent a halogen atom or an alkoxy group, and R represents a hydrogen atom or a methyl group.) The method for producing a transition metal compound-containing nanoparticle according to any one of claims 9 to 11 , wherein the step of protecting with the protective agent is performed in a solvent. The method for producing transition metal compound-containing nanoparticles according to any one of claims 9 to 12 , wherein the step of forming the transition metal carbide is performed at 150 to 400 ° C. The method for producing transition metal compound-containing nanoparticles according to any one of claims 9 to 13 , wherein the step of forming the transition metal carbide is performed in an argon gas atmosphere. A transition metal compound-containing nanoparticle-dispersed ink comprising the transition metal compound-containing nanoparticle according to any one of claims 1 to 8 and a hydrophilic solvent.   One or more compounds (U) selected from the group consisting of transition metal carbides, transition metal nitrides and transition metal sulfides, a protective agent having an organic group containing a linking group and a hydrophilic group, and a hydrophilic solvent. A transition, characterized in that it is used for preparing the transition metal compound-containing nanoparticles according to claim 1 and / or for forming a film containing the transition metal compound-containing nanoparticles according to claim 1. Metal compound-containing nanoparticle-dispersed ink.   A solution containing a transition metal complex containing any atom of carbon, nitrogen or sulfur, a protective agent having an organic group containing a linking group and a hydrophilic group, and a hydrophilic solvent having a boiling point of 160 to 260 ° C. A method for producing a transition metal compound-containing nanoparticle-dispersed ink, comprising a step of heating at 250 ° C. and used for preparing the transition metal compound-containing nanoparticles according to claim 1. A device having two or more electrodes opposed to each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes,
The said hole injection transport layer contains the transition metal compound containing nanoparticle as described in any one of the said Claims 1 thru | or 6 at least, The device characterized by the above-mentioned. 19. The device according to claim 18 , further comprising a charge transport layer comprising a charge transport compound that can be dissolved and / or dispersed in a hydrophobic solvent adjacent to the hole injection transport layer. The device according to claim 18 or 19 , wherein the hole injection transport layer contains two or more kinds of the transition metal compound-containing nanoparticles. The device according to any one of claims 18 to 20 , wherein the device is an organic EL element including an organic layer including at least a light emitting layer. The device is an organic transistor having a gate electrode, an insulating layer, a source electrode and a drain electrode, and an organic semiconductor layer on a substrate, wherein the transition metal compound-containing nanoparticles are formed on at least a part of the surface of the source electrode and the drain electrode. characterized in that an organic transistor having a device according to any one of claims 18 to 20. 16. A method for producing a device comprising two or more electrodes facing each other on a substrate and a hole injection / transport layer disposed between the two electrodes, wherein the transition metal compound-containing nanoparticles according to claim 15 are used. Forming a hole injecting and transporting layer on any of the layers on the electrode by using a dispersed ink. 17. A method for producing a device comprising two or more electrodes facing each other on a substrate and a hole injecting and transporting layer disposed between the two electrodes, wherein the transition metal compound-containing nanoparticles according to claim 16 are used. Forming a hole injecting and transporting layer on any layer on the electrode using the dispersed ink; and
A step of oxidizing the compound (U). The method for manufacturing a device according to claim 24 , wherein a step of oxidizing the compound (U) is performed after the step of forming the hole injection transport layer. The device manufacturing method according to claim 24 , wherein a step of oxidizing the compound (U) is performed before the step of forming the hole injection transport layer. In the step of oxidizing the compound (U), the heating means, using means for applying a light irradiation means or active oxygen, characterized by oxidizing the compound (U), any one of claims 24 to 26 A method for manufacturing a device according to one item. A step of forming a charge transport layer by coating a hydrophobic solution containing a charge transport compound and a hydrophobic solvent which can be dissolved and / or dispersed in a hydrophobic solvent adjacent to the hole injection transport layer. The device manufacturing method according to any one of claims 23 to 27 , comprising: The device is characterized in that an organic EL device comprising an organic layer containing at least a light emitting layer, method of manufacturing a device according to any one of claims 23 to 28. The device is an organic transistor having a gate electrode, an insulating layer, a source electrode and a drain electrode, and an organic semiconductor layer on a substrate, wherein the transition metal compound-containing nanoparticles are formed on at least a part of the surface of the source electrode and the drain electrode. The device manufacturing method according to any one of claims 23 to 28 , comprising:

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