JP2001217075A - Method of manufacturing organic electroluminescence device and organic electroluminescence device - Google Patents

Abstract

[PROBLEMS] To easily obtain an organic EL element having a layer containing a conductive polymer and having a small leak current between adjacent pixels even when a pixel pitch is small. A layer containing an undoped conductive polymer is formed over a substrate having an electrode formed in a desired pattern, and a layer containing a conductive polymer is formed over the substrate. Thereafter, the conductive polymer is dedoped to form a laminate. Further, the laminate is immersed in an electrolytic solution containing ions, which has been adjusted to an acidity at which doping of ions for doping the conductive polymer does not substantially occur, and using the electrode formed in a desired pattern. By passing a current through the electrolytic solution, the conductive polymer is electrochemically doped with the ions. The light-emitting layer contains one or more kinds of predetermined repeating units, the total of those repeating units is 50 mol% or more and 100 mol% or less of all the repeating units, and the number average molecular weight in terms of polystyrene is 10 ³ to 10 ⁸ . An organic EL element containing a certain polymer fluorescent substance is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an organic electroluminescence device (hereinafter, sometimes referred to as an organic EL device) and an organic EL device obtained by the method.

[0002]

[Prior art]

[0003] In recent years, an organic EL device having a two-layer structure in which an organic fluorescent dye is used as a light emitting layer and an organic charge transport compound used for an electrophotographic photoreceptor or the like has been disclosed (Japanese Patent Application Laid-Open (JP-A) no. JP-A-59-194393). Organic EL devices are characterized by being able to easily emit light of many colors in addition to low voltage driving and high luminance, compared to inorganic electroluminescent devices.
Many improvements have been reported for organic charge transport compounds [Japanese Journal of Applied Physics (Jpn. J. Appl. Phys.) No. 2].
7, L269 (1988)], [Journal of Applied Physics (J. Appl. Phys.)
s. ) 65, 3610 (1989)].

[0004] In the organic EL device, by providing a layer made of a conductive polymer between the electrode and the light emitting layer,
The improvement of the light emission characteristics of the device is disclosed in
No. 5192. As a method of providing a layer made of a conductive polymer on an organic EL element, a method of applying a doped conductive polymer to a electrode from a solvent (WO9)
7/32452) and a method of forming a doped conductive polymer on an electrode by electrolytic polymerization (JP-A-9-97679). These methods have a problem that when the pixel pitch is small, the leak current between adjacent pixels is large.

[0005] In order to solve the above-mentioned problem, a doped conductive polymer is formed on the entire surface, then is partially exposed using a photoresist, and then is doped only in a necessary portion by a method such as undoping. There is disclosed a method for reducing a leak current between adjacent pixels by providing a conductive polymer layer (Japanese Patent Application Laid-Open No. H11-195491).
However, this method has a problem that, in addition to the requirement of the accuracy of the alignment between the electrode and the resist pattern, the process is complicated, such as an increase in the number of steps because a photoresist is used.

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic EL device having a layer containing a conductive polymer and having a small leak current between adjacent pixels even when the pixel pitch is small. An object of the present invention is to provide a manufacturing method for obtaining the same and an organic EL device obtained by the manufacturing method, which contains a specific polymer fluorescent substance and does not increase the leak current between adjacent pixels.

[0006]

Means for Solving the Problems The present inventors have made intensive studies in view of such circumstances, and as a result, (A) covering the electrodes on a substrate having electrodes formed in a desired pattern,
(A) forming a layer containing a undoped conductive polymer, or (b) forming a layer containing a conductive polymer and then undoping the conductive polymer to form a laminate. And (B) immersing the laminate in a specific electrolytic solution, and applying an electric current to the electrolytic solution using the electrode formed in the desired pattern, thereby electrochemically forming the conductive polymer on the conductive polymer. It has been found that the above problem can be solved by a manufacturing method including a step of doping the ions, and the present invention has been accomplished.

[0007] That is, the present invention relates to [1] an organic material having at least a layer containing a conductive polymer and a light emitting layer containing an organic light emitting material between a pair of anodes and cathodes, at least one of which is transparent or translucent. The present invention relates to a method for manufacturing an organic electroluminescent device, which includes the following steps (A) and (B). (A) over a substrate having an electrode formed in a desired pattern, covering the electrode, (a) forming a layer containing a undoped conductive polymer, or (b) forming a conductive polymer. Forming a layer containing, and dedoping the conductive polymer to form a laminate, (B) substantially no doping of the laminate with ions for doping the conductive polymer occurs. The electrode is immersed in an electrolyte solution containing the ions adjusted to the acidity, and the electrolyte is electrochemically applied to the conductive polymer by applying an electric current to the electrolyte solution using the electrode formed in the desired pattern. A step of doping ions; The present invention also provides
[2] The light emitting layer prepared by the production method of the above [1], wherein the light emitting layer contains at least one kind of a repeating unit represented by the following formula (1) as an organic light emitting material, and the total of those repeating units is all the repeating units. And the number average molecular weight in terms of polystyrene is 10 ³ to 100 mol%.
The present invention relates to an organic electroluminescence device including a polymer fluorescent substance of 10 ⁸ .

Embedded image -Ar _1- (CR ₁ = CR ₂ ) _n- (1) [where Ar ₁ is an arylene having 6 to 60 carbon atoms contained in the main chain portion. It is a divalent heterocyclic compound group having from 4 to 60 carbon atoms contained in the group or the main chain, and may be unsubstituted or have one or more substituents. R ₁ and R ₂ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms, a heterocyclic compound group having 4 to 60 carbon atoms, and a cyano group. Represents a group. The aryl group and the heterocyclic compound group may further have a substituent. n is 0 or 1. Further, the present invention relates to [3] a planar light source using the organic electroluminescence device of [2]. Next, the present invention relates to [4] a segment display device using the organic electroluminescence element of [2]. Next, the present invention relates to [5] a dot matrix display device using the organic electroluminescence device of [2]. Further, the present invention relates to [6] a liquid crystal display device using the organic electroluminescence element of [2] as a backlight. [Detailed description of the invention]

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for manufacturing an organic EL device of the present invention and an organic EL device of the present invention will be described in detail.

[0009] The method of manufacturing an organic EL device of the present invention is characterized by including the following steps (A) and (B). (A) over a substrate having an electrode formed in a desired pattern, covering the electrode, (a) forming a layer containing an undoped conductive polymer, or (b)
A step of forming a layer containing a conductive polymer and then undoping the conductive polymer to form a laminate; and (B) doping the laminate with ions that dope the conductive polymer. It is immersed in an electrolytic solution containing the ions, which is adjusted to an acidity that does not occur naturally, and is supplied with electricity through the electrolytic solution using the electrode formed in the desired pattern, so that the conductive polymer is electrically charged. A step of chemically doping the ions.

In the step (A), the desired pattern is an electrode pattern for determining the shape of a pixel that emits light when the organic EL element is driven. In the case of (1), it means a plurality of stripe-shaped electrode patterns, and in the case of a segment element, it means a segment electrode pattern having a specific shape. As a method of forming an electrode in a desired pattern, an electrode once formed on the entire surface of the substrate, a method of patterning using a photoresist or the like, a method of forming an electrode by sputtering or vapor deposition through a mask of a desired pattern, A method of covering the surface of the electrode with a desired pattern by using an insulating thin film is exemplified. As a method for forming the laminate, the above method (a) or (b) can be used. That is, the method (a) is a method of forming a layer containing the undoped conductive polymer on the substrate, covering the electrode, and forming a laminate.
The method (b) is a method in which a layer containing a conductive polymer is formed on the substrate so as to cover the electrode, and then the conductive polymer is dedoped to form a laminate. In the above method (a) or (b), the method of forming a layer containing a (de-doped) conductive polymer on the surface having the electrode, over the substrate, over the electrode, Although not limited, a method of dissolving or dispersing a conductive polymer in a solvent and then forming it on a surface having the electrode by coating; forming a layer containing the conductive polymer on the surface having the electrode; A method in which a monomer or oligomer of a conductive polymer is vapor-deposited or coated on the surface having the electrodes and then polymerized.

[0011] Dedoping refers to removing the dopant contained in the conductive polymer to make it into a state with less dopant, usually substantially undoped. Examples of the undoping method include, when the dopant is an anion, a method of immersion in an alkali solution, a method of contacting with a solid alkali, and the like.When the dopant is a cation, a method of immersion in an acid solution, Examples of the method include contact with an acidic solid. In addition, undoping can be performed by a method of washing with a large amount of a solvent containing no ion, a method of electrochemically removing a dopant, and the like. A method for forming a layer by coating can be appropriately selected in consideration of the solubility and film formability of the conductive polymer. The layer containing the conductive polymer may be formed on and around the electrode, and need not be limited to the electrode.

As the conductive polymer used in the present invention, any polymer may be used as long as its conductivity is increased by electrochemical doping.
Those which increase by 000 times or more are more preferable. For example, Bulletin of Chemical Society of Japan (Bull. Chem. Soc. Jpn.), 72
Vol. 4, 621 (1999) and references thereto, Plastics, Vol. 7, 35 pages (1
994) and its references, Polymer Processing, 45,
8, No. 2 (338) (1996) and references thereto, Fine Chemicals, Vol. 25, No. 8, page 52 (199)
6 years) and those having the above properties among the polymer compounds described in the references. Specifically, polyaniline and its derivatives, polythiophene and its derivatives, polypyrrole and its derivatives, polyarylenevinylene and its derivatives, polyquinoline and its derivatives, polyquinoxaline and its derivatives,
Examples thereof include polymers containing an aromatic amine structure. Here, the polymer containing an aromatic amine structure is a polymer having a low molecular weight aromatic amine in a main chain or a side chain, for example, having a triphenylamine or carbazole derivative in a side chain, and Examples thereof include polymers having a chain of polyolefin, polyester, polysiloxane, polysilane, and the like, and polymers in which a derivative of triphenylamine or carbazole is linked by an ether, ester, carbonyl, silicon atom, siloxane, or the like. If the undoping of the conductive polymer is insufficient, the electric conductivity is not low, and the leak current between pixels may increase. The solution or dispersion to be applied may contain components other than the conductive polymer. The components other than the conductive polymer and the amounts thereof may be selected within a range that does not impair the film quality or electrical characteristics. Examples of other components include a stabilizer, a dispersant, a surfactant, a surface treatment agent, and an antioxidant.

[0013] In the step (B), the laminate prepared in the step (A) is adjusted to an acidity such that doping of ions for doping the conductive polymer does not substantially occur. The conductive polymer is electrochemically doped with the ions by immersing it in the electrolyte solution containing the ions and applying current to the electrolyte solution using the electrodes formed on the substrate.

The kind of ions to be doped into the conductive polymer is an anion when the layer is a hole injection layer, and a cation when the layer is an electron injection layer. Examples of anions include polystyrenesulfonate, alkylbenzenesulfonate, camphorsulfonate, and the like.Examples of cations include lithium, sodium,
Examples thereof include a potassium ion and a tetrabutylammonium ion. When at least one of the ions doped into the conductive polymer is a polymer ion having a number average molecular weight of 10 ³ to 10 ^{7 in} terms of polystyrene, it is undoped even after washing after doping. It is preferable because it is difficult. In addition, when at least one of the ions doped into the conductive polymer is an ionic dye, the emission color of the organic EL device can be changed. As the ionic dye, a dye that absorbs light from the light emitting layer may be used,
A fluorescent dye may be used to convert light from the light emitting layer into light of another wavelength. Specifically, as the ionic dye, a dye that contains a sulfonic acid group or a carboxylic acid group in the molecule and exhibits anionicity can be used, and the chemical structure is monoazo or polyazo, triphenylmethane, anthraquinone, An indigoid type is exemplified. These may be sodium, potassium or ammonium salts. In addition, a dye that contains a basic group such as a substituted amino group in the molecule and exhibits cationicity can also be used.The chemical structure is diarylmethane, triarylmethane, xanthene, thiazine, azine, An azo type, an azomethine type, a quinone type and the like are exemplified. Further, coumarin-based, styryl-based, squarylium-based and spiropyran-based dyes having the above-mentioned ionic functional group can be used.

[0015] The electrolytic solution containing the ions adjusted to an acidity at which doping of the ions to be doped into the conductive polymer does not substantially occur is an electrolytic solution prepared to be almost neutral, Specifically, the conductive polymer contains ions that can be doped into the conductive polymer as an electrolyte. However, the counter ions to the ions are contained in substantially equal amounts at the same time, so that doping of the ions substantially occurs. There is no electrolyte. When the solvent of the electrolyte is water, the acidity is represented by pH, and the pH is, for example, 5 to 9, preferably 6 to 8
It is. The pH may simply be a color corresponding to 6 to 8 on pH test paper. In order to perform doping, a part or the whole of the substrate is immersed in an electrolytic solution adjusted to have an acidity that does not substantially cause doping, and current is applied. The electrolytic solution contains ions that can be doped into the conductive polymer, and contains a conductive polymer by being energized using an electrode having a desired pattern formed on a substrate. The portion of the layer above the electrode is electrochemically doped with the ions. At this time, when there are a plurality of electrodes, it is possible to electrochemically dope only a portion on the electrode by supplying a current to only a specific electrode.

[0016] In the electrochemical doping, the amount of doping can be controlled by the amount of electricity to be supplied, so that the electrical characteristics of the device can be finely controlled. Further, all of them can be simultaneously doped using an electrolytic solution containing two or more kinds of ions. For example, if a polystyrene sulfonate ion for increasing electric conductivity and an ionic dye for coloring are used at the same time, the electrical and optical characteristics of the device can be more finely controlled. In addition, 2
A thin film in which two or more kinds of dopants are respectively doped only on a specific electrode can be formed by using more than one kind of electrolytic solution and conducting a current to another electrode to dope each. For example, it is possible to selectively dope ionic dyes corresponding to red, green, and blue to the electrodes corresponding to the respective colors to achieve multicolor.

The production method of the present invention only needs to include the above-mentioned steps (A) and (B). Unless contrary to the object of the present invention, before or after each step, or within each step, Other operations and processes may be included.

Next, the organic EL device of the present invention will be described.
The organic EL device of the present invention is produced by the above-described manufacturing method of the present invention, and the light emitting layer contains at least one kind of a repeating unit represented by the following formula (1) as an organic light emitting material. It is characterized by including a polymeric fluorescent substance whose total is 50 mol% or more and 100 mol% or less of all the repeating units and whose polystyrene equivalent number average molecular weight is 10 ³ to 10 ⁸ .

Embedded image -Ar _1- (CR ₁ = CR ₂ ) _n- (1) [where Ar ₁ is an arylene having 6 to 60 carbon atoms contained in the main chain portion. It is a divalent heterocyclic compound group having from 4 to 60 carbon atoms contained in the group or the main chain, and may be unsubstituted or have one or more substituents. R ₁ and R ₂ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms, a heterocyclic compound group having 4 to 60 carbon atoms, and a cyano group. Represents a group. The aryl group and the heterocyclic compound group may further have a substituent. n is 0 or 1. ]

[0019] The structure of the organic EL device of the present invention includes a device having a layer containing a conductive polymer adjacent to the electrode between the electrode and the light emitting layer, and an anode between the anode and the light emitting layer. A layer containing a conductive polymer is provided adjacent to the element, an electron transport layer is provided between the cathode and the light emitting layer, a hole transport layer is provided between the anode and the light emitting layer, and the cathode and the light emitting layer are provided. An element in which a layer containing a conductive polymer is provided adjacent to the cathode, an electron transport layer is provided between the cathode and the light emitting layer, and a hole transport layer is provided between the anode and the light emitting layer. An element in which a layer containing a conductive polymer is provided adjacent to the anode between the anode and the hole transport layer, a hole transport layer is provided between the anode and the light emitting layer, and a cathode and a light emitting layer are provided. And an element in which a layer containing a conductive polymer is provided between the cathode and the electron transport layer adjacent to the cathode. For example, the following structures a) to h) are specifically exemplified. a) anode / layer containing conductive polymer / light emitting layer / cathode b) anode / light emitting layer / layer containing conductive polymer / cathode c) anode / layer containing conductive polymer / hole transport layer / light emission Layer / cathode d) anode / hole transport layer / light-emitting layer / layer containing conductive polymer / cathode e) anode / layer containing conductive polymer / light-emitting layer / electron transport layer / cathode f) anode / light-emitting layer / Electron transport layer / layer containing conductive polymer / cathode g) anode / layer containing conductive polymer / hole transport layer / light emitting layer / electron transport layer / cathode h) anode / hole transport layer / light emitting layer / Electron transporting layer / layer containing conductive polymer / cathode (where / indicates lamination) Here, the light emitting layer is a layer containing a light emitting material and having a function of emitting light, and a hole transporting layer. Is a layer containing a hole transport material and having a function of transporting holes, and the electron transport layer
A layer containing an electron transport material and having a function of transporting electrons. Note that the electron transport layer and the hole transport layer are collectively referred to as a charge transport layer. Further, among the charge transport layers provided adjacent to the electrodes, those having a function of improving the charge injection efficiency from the electrodes are particularly called charge injection layers (hole injection layers, electron injection layers). The light emitting layer, the hole transporting layer, and the electron transporting layer may be each independently used in two or more layers. In order to improve the adhesion to the electrode and the charge injection from the electrode, the charge injection is performed adjacent to the electrode. A layer may be provided, or a thin buffer layer may be inserted at the interface between the charge transport layer and the light-emitting layer to improve adhesion at the interface and prevent mixing. The order and number of layers to be laminated and the thickness of each layer are not particularly limited, and can be appropriately used in consideration of luminous efficiency and element life.
The layer containing a conductive polymer is a kind of charge injection layer adjacent to the electrode, and is provided adjacent to the electrode, and has an effect of lowering a driving voltage of the element by improving charge injection efficiency from the electrode. It has. Specifically, in the doped region on the electrode, the electric conductivity of the conductive polymer is usually 10 ⁻⁵ S / cm or more and 10 ⁴ S / cm or less, and 10 ⁻³ S / cm or more. preferably 10 ³ S / cm or less, 10 ^- and particularly preferably ¹ S / cm or more 10 ³ S / cm or less. The undoped regions other than the electrodes have a lower electrical conductivity than the doped regions on the electrodes, usually less than 10 ^-5 S / cm, and substantially reduce the leakage between the electrodes. Functions as an insulator to prevent. In the case of a conductive polymer, the electrical conductivity can be generally 10 ⁻⁵ S / cm or more and 10 ⁴ or less by doping an appropriate amount of ions. Although the electric conductivity of the undoped region is higher than that of the undoped region, in order to reduce both the driving voltage and the leakage current between the luminescent pixels, the electric conductivity of the doped region is lower than that of the undoped region. 10 than electrical conductivity
It is preferably at least 0 times, more preferably at least 1000 times.

[0020] The thickness of the layer containing the conductive polymer is, for example, 1 nm to 100 nm, and preferably 2 nm to 50 nm. Note that a charge injection layer may be provided in addition to the layer containing the conductive polymer, and examples of a material used in such a case include metal phthalocyanine (eg, copper phthalocyanine) and carbon. The organic light emitting material used for the light emitting layer of the organic EL device of the present invention is a polymer phosphor represented by the following formula (1).

Embedded image -Ar _1- (CR ₁ = CR ₂ ) _n- (1) [where Ar ₁ is an arylene having 6 to 60 carbon atoms contained in the main chain portion. It is a divalent heterocyclic compound group having from 4 to 60 carbon atoms contained in the group or the main chain, and may be unsubstituted or have one or more substituents. R ₁ and R ₂ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms, a heterocyclic compound group having 4 to 60 carbon atoms, and a cyano group. Represents a group. The aryl group and the heterocyclic compound group may further have a substituent. n is 0 or 1. Ar ₁ has 6 to 6 carbon atoms contained in the main chain portion.
An arylene group of 0 or less, or a heterocyclic compound group of 4 to 60 carbon atoms contained in the main chain portion.

Ar ₁ may be selected so as not to impair the fluorescent properties of the polymeric fluorescent substance, and specific examples include the divalent groups exemplified in Chemical Formulas 5 to 18 below.

[0022]

[Formula 5]

[Formula 6]

Embedded image

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Here, R independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, and 1 to 6 carbon atoms.
0 alkylsilyl group, C1-C40 alkylamino group, C6-C60 aryl group, C6-C60 aryloxy group, C6-C60 arylalkyl group, C7-C60 Arylalkoxy group having 8 carbon atoms
A group selected from the group consisting of an arylalkenyl group having from 60 to 60, an arylalkynyl group having from 8 to 60 carbon atoms, an arylamino group having from 6 to 60 carbon atoms, a heterocyclic compound group having from 4 to 60 carbon atoms, and a cyano group. In the above example, 1
Although a plurality of Rs are contained in one structural formula, they may be the same or different, and each is independently selected. When Ar ₁ has a plurality of substituents, they may be the same or different. In order to enhance the solubility in a solvent, the compound preferably has at least one substituent that is not a hydrogen atom, and preferably has low symmetry in the shape of the repeating unit including the substituent.

In the case where R is a substituent other than a hydrogen atom or a cyano group, examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group. , Heptyl group, octyl group, nonyl group, decyl group, lauryl group and the like,
Pentyl, hexyl, octyl and decyl groups are preferred.

The alkoxy group having 1 to 20 carbon atoms includes a methoxy group, an ethoxy group, a propyloxy group, a butoxy group,
Examples include a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, and a lauryloxy group, and a pentyloxy group, a hexyloxy group, an octyloxy group, and a decyloxy group are preferable.

Examples of the alkylthio group having 1 to 20 carbon atoms include methylthio, ethylthio, propylthio, butylthio, pentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio, laurylthio and the like. And a pentylthio group, a hexylthio group, an octylthio group and a decylthio group.

The alkylsilyl group having 1 to 60 carbon atoms includes
Methylsilyl group, ethylsilyl group, propylsilyl group,
Butylsilyl, pentylsilyl, hexylsilyl, heptylsilyl, octylsilyl, nonylsilyl, decylsilyl, laurylsilyl, trimethylsilyl, ethyldimethylsilyl, propyldimethylsilyl, butyldimethylsilyl, pentyldimethylsilyl Group, hexyldimethylsilyl group, heptyldimethylsilyl group, octyldimethylsilyl group, nonyldimethylsilyl group, decyldimethylsilyl group, lauryldimethylsilyl group, etc., and pentylsilyl group, hexylsilyl group, octylsilyl group, decylsilyl group. And a pentyldimethylsilyl group, a hexyldimethylsilyl group, an octyldimethylsilyl group and a decyldimethylsilyl group.

As the alkylamino group having 1 to 40 carbon atoms,
Methylamino group, dimethylamino group, ethylamino group,
Propylamino group, butylamino group, pentylamino group, hexylamino group, heptylamino group, octylamino group, nonylamino group, decylamino group, laurylamino group, etc., pentylamino group, hexylamino group, octylamino group, A decylamino group is preferred.

The aryl group having 6 to 60 carbon atoms includes a phenyl group and a C ₁ -C ₁₂ alkoxyphenyl group (C ₁ -C ₁₂ is
It shows that it has 1 to 12 carbon atoms. The same applies to the following. ), C ₁ -C ₁₂ alkylphenyl group, 1-naphthyl group, 2-naphthyl group and the like, C ₁ -C ₁₂ alkoxyphenyl group, is C ₁ -C ₁₂ alkylphenyl group are preferable.

The aryloxy group having 6 to 60 carbon atoms includes
Phenoxy group, C ₁ -C ₁₂ alkoxyphenoxy group, C ₁
-C ₁₂ alkylphenoxy group, 1-naphthyloxy group,
Examples thereof include a 2-naphthyloxy group, and a C ₁ -C ₁₂ alkoxyphenoxy group and a C ₁ -C ₁₂ alkylphenoxy group are preferred.

The arylalkyl group having 6 to 60 carbon atoms includes a phenyl-C ₁ -C ₁₂ alkyl group, a C ₁ -C ₁₂ alkoxyphenyl-C ₁ -C ₁₂ alkyl group, and a C ₁ -C ₁₂ alkylphenyl-C ₁ -C ₁₂ alkyl group, 1-naphthyl -C ₁
-C ₁₂ alkyl group, 2-naphthyl -C ₁ -C ₁₂ alkyl groups and the like, C ₁ -C ₁₂ alkoxyphenyl -C ₁
-C ₁₂ alkyl group, C ₁ -C ₁₂ alkylphenyl-C _1-
C ₁₂ alkyl groups are preferred.

As the arylalkoxy group having 6 to 60 carbon atoms, phenyl-C ₁ -C ₁₂ alkoxy group, C ₁ -C ₁₂ alkoxyphenyl-C ₁ -C ₁₂ alkoxy group, C ₁ -C ₁₂ alkylphenyl-C ₁ -C ₁₂ alkoxy groups, 1-naphthyl -C ₁ -C ₁₂ alkoxy groups, 2-naphthyl -C ₁ -C ₁₂
An alkoxy group and the like, C ₁ -C ₁₂ alkoxyphenyl -C ₁ -C ₁₂ alkoxy group, C ₁ -C ₁₂ alkylphenyl -C ₁ -C _{1 2} alkoxy group.

The arylamino group having 6 to 60 carbon atoms includes
Phenylamino group, diphenylamino group, C ₁ -C ₁₂ alkoxyphenyl amino group, di (C ₁ -C ₁₂ alkoxyphenyl) amino group, di (C ₁ -C ₁₂ alkylphenyl) amino groups, 1-naphthylamino group, naphthylamino group and the like, C ₁ -C ₁₂ alkylphenyl group, di (C ₁ -C ₁₂ alkylphenyl) amino group are preferable.

Examples of the heterocyclic compound group having 4 to 60 carbon atoms include a thienyl group, a C ₁ -C ₁₂ alkylthienyl group, a pyrrolyl group, a furyl group, a pyridyl group, and a C ₁ -C ₁₂ alkylpyridyl group. a thienyl group, C ₁ -C ₁₂ alkyl thienyl group, a pyridyl group, a C ₁ -C ₁₂ alkyl pyridyl group are preferable.

Among the examples of R, in the substituents containing an alkyl chain, they may be straight-chain, branched or cyclic, or a combination thereof. A 2-ethylhexyl group,
3,7-dimethyloctyl group, cyclohexyl group, 4-
Examples thereof include a C ₁ -C ₁₂ alkylcyclohexyl group. To increase the solubility of the polymeric fluorescent substance in the solvent,
It is preferred that at least _one of the substituents of Ar ₁ contains a cyclic or branched alkyl chain. Further, the tips of two alkyl chains may be linked to form a ring. Further, some carbon atoms of the alkyl chain may be replaced by a group containing a hetero atom, and examples of the hetero atom include an oxygen atom, a sulfur atom, and a nitrogen atom. Further, among the examples of R, when an aryl group or a heterocyclic compound group is included in a part thereof, they may further have one or more substituents.

In the above formula (1), n is 0 or 1. R ₁ and R ₂ in the above formula (1) each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a 6 to 6 carbon atoms.
And a group selected from the group consisting of an aryl group having 0, a heterocyclic compound group having 4 to 60 carbon atoms, and a cyano group.

In the case where R ₁ and R ₂ are substituents other than a hydrogen atom or a cyano group, examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group,
Examples thereof include a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group and a lauryl group, and a methyl group, an ethyl group, a pentyl group, a hexyl group, a heptyl group and an octyl group are preferred.

Examples of the aryl group having 6 to 60 carbon atoms include a phenyl group, a C ₁ -C ₁₂ alkoxyphenyl group, a C ₁ -C ₁₂ alkylphenyl group, a 1-naphthyl group and a 2-naphthyl group. The groups C ₁ -C ₁₂ alkylphenyl are preferred.

Examples of the heterocyclic compound group having 4 to 60 carbon atoms include a thienyl group, a C ₁ -C ₁₂ alkylthienyl group, a pyrrolyl group, a furyl group, a pyridyl group, and a C ₁ -C ₁₂ alkylpyridyl group. a thienyl group, C ₁ -C ₁₂ alkyl thienyl group, a pyridyl group, a C ₁ -C ₁₂ alkyl pyridyl group are preferable.

Further, the terminal group of the polymeric fluorescent substance is protected with a stable group, since if the polymerization active group remains as it is, the light emitting characteristics and life of the element may be reduced. Is also good. Those having a conjugate bond continuous with the conjugate structure of the main chain are preferable, and examples thereof include a structure in which the conjugate structure is bonded to an aryl group or a heterocyclic compound group via a vinylene group. Specifically, substituents described in Chemical Formula 10 of JP-A-9-45478 are exemplified.

As a method for synthesizing the polymeric fluorescent substance, when a main chain has a vinylene group, for example, Japanese Patent Application Laid-Open No. H5-220235
No. 5 publication. That is, Witti of a dialdehyde compound and a diphosphonium salt compound
g reaction, polymerization of divinyl compound and dihalogen compound or Heck reaction of vinyl halide compound alone, Horner-Wadsworth-Emm of dialdehyde compound and diphosphite compound
polymerization by the ons method, polycondensation of a compound having two methyl halide groups by a dehydrohalogenation method, polycondensation of a compound having two sulfonium bases by a decomposition method of a sulfonium salt, Knoevenagel reaction of a dialdehyde compound and a diacetonitrile compound , Polymerization of dialdehyde compounds by McMurry reaction, aromatic Schiff salt and Siegrist of compounds having methyl group
Methods such as polymerization by reaction are exemplified.

When the main chain has no vinylene group,
For example, a method of polymerizing the corresponding monomer by a Suzuki coupling reaction, a method of polymerization by a Grignard reaction, a method of polymerization by a Ni (0) catalyst, F
Examples thereof include a method of polymerizing with an oxidizing agent such as eCl _3, a method of electrochemical oxidative polymerization, and a method of decomposing an intermediate polymer having an appropriate leaving group.

The polymeric fluorescent substance may contain a repeating unit other than the repeating unit represented by the formula (1) as long as the fluorescent property and the charge transporting property are not impaired. Further, the repeating unit represented by the formula (1) and other repeating units are represented by the following formula:
They may be linked by non-conjugated units, or their non-conjugated portions may be contained in the repeating unit. Examples of the bonding structure include a compound represented by the following chemical formula (19), a combination of a compound represented by the following chemical formula (19) and a vinylene group, and a compound represented by the following chemical formula (19):
And combinations of two or more of the above. Here, R is a group selected from the same substituents as described above, and Ar represents a hydrocarbon group having 6 to 60 carbon atoms.

Embedded image Further, the polymeric fluorescent substance may be a random, block or graft copolymer, or a polymer having an intermediate structure between them, for example, a random copolymer having a block property. . From the viewpoint of obtaining a polymer fluorescent substance having a high fluorescence quantum yield, a random copolymer having block properties or a block or graft copolymer is preferable to a completely random copolymer. The case where the main chain is branched and there are three or more terminal portions, and dendrimers are also included.

Further, since light emission from a thin film is utilized, a polymer fluorescent substance having fluorescence in a solid state is preferably used. Examples of good solvents for the polymeric fluorescent substance include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene, mesitylene, tetralin, decalin, and n-butylbenzene.
Although it depends on the structure and molecular weight of the polymeric fluorescent substance, it can be usually dissolved in these solvents in an amount of 0.1% by weight or more.

The polymeric fluorescent substance has a molecular weight of 10 ³ to 10 ⁸ in terms of polystyrene, and the degree of polymerization thereof varies depending on the repeating structure and its ratio. In general, the total number of the repeating structures is preferably from 20 to 1000 from the viewpoint of film-forming properties.
0, more preferably 30 to 10,000, particularly preferably 50 to 5,000.

When these polymer fluorescent materials are used as a light emitting material of an organic EL device, the purity affects the light emitting characteristics. Therefore, the monomer before polymerization is purified by a method such as distillation, sublimation purification, or recrystallization. It is preferable that after the synthesis, a purification treatment such as reprecipitation purification or fractionation by chromatography is performed.

When a film is formed from a solution by using these organic solvent-soluble polymeric fluorescent materials when preparing an organic EL device, it is only necessary to remove the solvent by drying after coating this solution, The same method can be applied to a case where a transport material and a light-emitting material are mixed, which is very advantageous in production. As a method of forming a film from a solution, spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, screen printing, A coating method such as a flexographic printing method, an offset printing method, and an inkjet printing method can be used.

The optimum value of the thickness of the light emitting layer is different depending on the material used, and may be selected so that the driving voltage and the luminous efficiency have appropriate values. For example, the thickness is 1 nm to 1 μm, preferably 2 nm to 500 nm. And more preferably 5 nm to 200 nm.

In the method for manufacturing an organic EL device of the present invention,
A light emitting material other than the above-described polymeric fluorescent substance may be used for the light emitting layer, or a mixture thereof may be used. Further, in the organic EL device of the present invention, a light emitting material other than the above-described polymeric fluorescent substance may be mixed and used in the light emitting layer. As the light emitting material, known materials can be used. Examples of low molecular weight compounds include naphthalene derivatives, anthracene or derivatives thereof, perylene or derivatives thereof, polymethine-based, xanthene-based, coumarin-based, cyanine-based dyes, metal complexes of 8-hydroxyquinoline or derivatives thereof, and aromatic amines. , Tetraphenylcyclopentadiene or a derivative thereof, or tetraphenylbutadiene or a derivative thereof can be used. Specifically, for example, JP-A-57-51781 and JP-A-59-1
Known ones such as those described in Japanese Patent No. 94393 can be used.

When the organic EL device of the present invention has a hole transport layer, the hole transport material to be used includes polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, and a polysiloxane derivative having an aromatic amine in a side chain. , Pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, polyaniline or its derivatives, polythiophene or its derivatives, polypyrrole or its derivatives, poly (p-
Examples thereof include phenylene vinylene) or a derivative thereof, and poly (2,5-thienylene vinylene) or a derivative thereof.

Specifically, as the hole transport material, JP-A-6
3-70257, 63-175860,
Examples thereof include those described in JP-A-2-135359, JP-A-2-135361, JP-A-2-209988, JP-A-3-37992, and JP-A-3-152184.

Among these, as a hole transporting material used for the hole transporting layer, polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or Polymeric hole transport materials such as derivatives thereof, polythiophenes or derivatives thereof, polypyrrole or derivatives thereof, poly (p-phenylenevinylene) or derivatives thereof, and poly (2,5-thienylenevinylene) or derivatives thereof are preferable. Preferred are polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, and a polysiloxane derivative having an aromatic amine in a side chain or a main chain.
In the case of a low-molecular-weight hole transport material, it is preferable to use the material by dispersing it in a polymer binder.

[0053] Polyvinylcarbazole or a derivative thereof is obtained, for example, from a vinyl monomer by cation polymerization or radical polymerization.

Polysilanes and derivatives thereof are described in Chemical Review (Chem. Rev.) Vol.
Compounds described in page 59 (1989), British Patent GB2300196, and the like are exemplified. Although the synthesis methods described above can be used as the synthesis method, the Kipping method is particularly preferably used.

As the polysiloxane or its derivative, those having the structure of the above low-molecular-weight hole transporting material in the side chain or main chain are preferably used since the siloxane skeleton structure has almost no hole transporting property. Particularly, those having a hole transporting aromatic amine in the side chain or main chain are exemplified.

The method of forming the hole transport layer is not limited, but a method of forming a film from a mixed solution with a polymer binder is exemplified for the low molecular weight hole transport material. In the case of a polymer hole transport material, a method of forming a film from a solution is exemplified.

The solvent used for film formation from a solution is not particularly limited as long as it can dissolve the hole transport material. As the solvent, chloroform, methylene chloride, chlorine solvents such as dichloroethane, ether solvents such as tetrahydrofuran, toluene, aromatic hydrocarbon solvents such as xylene,
Examples thereof include ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate, butyl acetate and ethyl cellosolve acetate.

As a method of forming a film from a solution, spin coating from a solution, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, etc. A coating method such as a printing method, a screen printing method, a flexographic printing method, an offset printing method, and an inkjet printing method can be used.

As the polymer binder to be mixed, those which do not extremely inhibit charge transport are preferable, and those which do not strongly absorb visible light are suitably used. Examples of the polymer binder include polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, and polysiloxane.

The optimum value of the film thickness of the hole transport layer depends on the material used, and may be selected so that the driving voltage and the luminous efficiency have appropriate values. If the thickness is too large, the driving voltage of the element becomes high, which is not preferable. Therefore, the thickness of the hole transport layer is, for example, 1 nm to 1 μm,
It is preferably from 2 nm to 500 nm, and more preferably from 5 nm to 200 nm.

When the organic EL device of the present invention has an electron transporting layer, known electron transporting materials can be used, and oxadiazole derivatives, anthraquinodimethane or its derivatives, benzoquinone or its derivatives, Naphthoquinone or a derivative thereof, anthraquinone or a derivative thereof, tetracyanoanthraquinodimethane or a derivative thereof, a fluorenone derivative, diphenyldicyanoethylene or a derivative thereof, a diphenoquinone derivative, or a metal complex of 8-hydroxyquinoline or a derivative thereof, polyquinoline or a derivative thereof,
Examples thereof include polyquinoxaline or a derivative thereof, polyfluorene or a derivative thereof, and the like.

[0062] Specifically, JP-A-63-70257,
JP-A-63-175860, JP-A-2-135359
Gazette, JP-A-2-135361, JP-A-2-20998
No. 8, No. 3-37992, No. 3-15218
No. 4 is exemplified.

[0063] Of these, oxadiazole derivatives, benzoquinone or derivatives thereof, anthraquinone or derivatives thereof, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinolines or derivatives thereof, polyquinoxalines or derivatives thereof, polyfluorenes or derivatives thereof Is preferred, and 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,3 is preferable.
4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum, and polyquinoline are more preferred.

The method for forming the electron transporting layer is not particularly limited. For a low molecular weight electron transporting material, a vacuum evaporation method from a powder,
Or a method by film formation from a solution or molten state,
In the case of the polymer electron transport material, a method of forming a film from a solution or a molten state is exemplified. When forming a film from a solution or a molten state, a polymer binder may be used in combination.

The solvent used for film formation from a solution is not particularly limited as long as it can dissolve the electron transport material and / or the polymer binder. As the solvent, chloroform, methylene chloride, chlorine solvents such as dichloroethane, ether solvents such as tetrahydrofuran, aromatic hydrocarbon solvents such as toluene and xylene, acetone, ketone solvents such as methyl ethyl ketone, ethyl acetate, butyl acetate,
Ester solvents such as ethylcellosolve acetate are exemplified.

As a method of forming a film from a solution or a molten state,
Spin coating method, casting method, microgravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, flexographic printing method,
A coating method such as an offset printing method and an inkjet printing method can be used.

As the polymer binder to be mixed, those which do not extremely inhibit charge transport are preferable, and those which do not strongly absorb visible light are suitably used. Poly (N-vinylcarbazole) as the polymer binder,
Polyaniline or a derivative thereof, polythiophene or a derivative thereof, poly (p-phenylenevinylene) or a derivative thereof, poly (2,5-thienylenevinylene)
Or a derivative thereof, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, or polysiloxane.

The optimum value of the film thickness of the electron transporting layer depends on the material used, and may be selected so that the driving voltage and the luminous efficiency have appropriate values. It is necessary, and if it is too thick, the driving voltage of the element becomes high, which is not preferable. Therefore, the thickness of the electron transport layer is, for example, 1 nm to 1 μm,
It is preferably from 2 nm to 500 nm, and more preferably from 5 nm to 200 nm.

The substrate on which the organic EL device of the present invention is formed may be an electrode formed thereon, a layer made of a conductive polymer formed by coating, and any material which does not change during electrolytic doping, such as glass or plastic , A polymer film, a silicon substrate and the like. In the case of an opaque substrate, the opposite electrode is preferably transparent or translucent.

[0070] In the present invention, the anode side is preferably transparent or translucent, and as the material of the anode, a conductive metal oxide film, a translucent metal thin film, or the like is used. Specifically, a film (NESA) formed using a conductive glass made of indium oxide, zinc oxide, tin oxide, or a complex thereof, such as indium tin oxide (ITO) or indium zinc oxide. Such)
And gold, platinum, silver, copper and the like are used, and ITO, indium / zinc / oxide, and tin oxide are preferable. Examples of the manufacturing method include a vacuum evaporation method, a sputtering method, an ion plating method, and a plating method. Further, as the anode, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used. The thickness of the anode can be appropriately selected in consideration of light transmittance and electric conductivity.
m to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.
Further, on the anode, in order to facilitate charge injection, a layer made of a phthalocyanine derivative, a conductive polymer, carbon, or the like, or an average film thickness of 2 nm or less made of a metal oxide, a metal fluoride, an organic insulating material, or the like. A layer may be provided.

As a material for the cathode used in the organic EL device of the present invention, a material having a small work function is preferable. For example, lithium, sodium, potassium, rubidium, cesium,
Metals such as beryllium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and alloys of two or more thereof, or one of them An alloy of at least one of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, and tin, graphite, a graphite intercalation compound, or the like is used. Examples of alloys include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy,
A lithium-aluminum alloy, a lithium-magnesium alloy, a lithium-indium alloy, a calcium-aluminum alloy and the like can be given. The cathode may have a laminated structure of two or more layers. The thickness of the cathode can be appropriately selected in consideration of electric conductivity and durability.
m to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

As a method for producing the cathode, a vacuum deposition method, a sputtering method, a lamination method for thermocompression bonding a metal thin film, and the like are used. Further, a layer made of a conductive polymer or a layer made of a metal oxide, a metal fluoride, an organic insulating material, or the like having an average thickness of 2 nm or less may be provided between the cathode and the organic material layer. A protective layer for protecting the organic EL element may be provided. In order to use the organic EL device stably for a long period of time, it is preferable to attach a protective layer and / or a protective cover to protect the device from the outside.

As the protective layer, polymer compounds, metal oxides, metal fluorides, metal borides and the like can be used. Further, as the protective cover, a glass plate, a plastic plate having a surface subjected to low water permeability treatment, or the like can be used. Used for If the space is maintained by using the spacer, it is easy to prevent the element from being damaged. If the space is filled with an inert gas such as nitrogen or argon, oxidation of the cathode can be prevented. Makes it easier to prevent the element from damaging the element. It is preferable to take any one or more of these measures.

To obtain planar light emission using the organic EL device of the present invention, a planar anode and a planar cathode may be arranged so as to overlap. Also, in order to obtain patterned light emission,
A method in which a mask having a patterned window provided on the surface of the planar light-emitting element, a method in which an organic material layer of a non-light-emitting portion is formed to be extremely thick and substantially non-light-emitting, or one of an anode and a cathode Or a method of forming both electrodes in a pattern. By forming a pattern by any of these methods and arranging several electrodes so that they can be turned ON / OFF independently, a segment type display element capable of displaying numbers, characters, simple symbols, and the like can be obtained. Further, in order to form a dot matrix element, both the anode and the cathode may be formed in a stripe shape and arranged orthogonally. A partial color display and a multi-color display can be achieved by a method of separately applying a plurality of types of polymer fluorescent substances having different emission colors or a method using a color filter or a fluorescence conversion filter. The dot matrix element can be driven passively or may be driven actively in combination with a TFT or the like. These display elements can be used as display devices for computers, televisions, mobile terminals, mobile phones, car navigation systems, viewfinders of video cameras, and the like. Further, the planar light emitting element is a thin self-luminous element and can be suitably used as a planar light source for a backlight of a liquid crystal display device or a planar illumination light source. If a flexible substrate is used, it can be used as a curved light source or a display device.

[0075]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it should not be construed that the present invention is limited thereto. Here, as for the number average molecular weight, the number average molecular weight in terms of polystyrene was determined by gel permeation chromatography (GPC) using chloroform as a solvent.

Example 1 <Synthesis of polymeric fluorescent substance 1> 2-Methoxy-5- (2-ethylhexyloxy) p-xylylene dichloride
A solution of 6.72 g of tert-butoxy potassium dissolved in 30 g of THF was added dropwise at room temperature to a solution of 32 g dissolved in 300 g of THF, followed by a reaction at room temperature for 7 hours. Next, this reaction solution was poured into methanol containing 3.5 ml of glacial acetic acid, and the resulting red precipitate was collected by filtration. Next, the precipitate is washed with ethanol,
Subsequently, the substrate was repeatedly washed with a mixed solvent of ethanol / ion-exchanged water, and finally, washed with ethanol. This was dried under reduced pressure to obtain 1.3 g of a polymer. Next, this polymer was dissolved in toluene. The polymer solution was poured into methanol and purified by reprecipitation. After collecting the precipitate, the precipitate was dried under reduced pressure to obtain polymeric fluorescent substance 1.

The polystyrene-equivalent number average molecular weight of the polymeric fluorescent substance 1 was 9.9 × 10 ⁴ . The polymeric fluorescent substance 5
With regard to the structure of, a spectrum corresponding to poly (2-methoxy-5- (2-ethylhexyloxy) -p-phenylenevinylene) was obtained by ¹ H-NMR.

<Synthesis of Polyaniline> 18.6 g of aniline was dissolved in 800 ml of a 1N aqueous sulfuric acid solution and cooled to 0 to 5 ° C. 400 ml of 45.6 g of ammonium persulfate
In water and added dropwise over 30 minutes. After stirring for about 1 hour to react, the precipitate was collected by filtration. The precipitate was immersed in a 1N LiOH aqueous solution and stirred for 1 hour to perform a de-doping treatment. Then, the pH of the filtrate was 7
After washing with water and then with methanol four times, drying was performed at 60 ° C. for 6 hours to obtain 12.7 g of polyaniline. This polyaniline was soluble in N-methylpyrrolidone.

<Preparation and Evaluation of Element> Hereinafter, description will be made with reference to FIG. 1 (process sectional view). An ITO film having a thickness of 150 nm was formed on the glass substrate 1 by a sputtering method, and the ITO was formed into a stripe of 2 mm width × 7 by etching.
An ITO electrode 2 formed in a pattern was formed (A).
On the glass substrate 1, covering the ITO electrode 2, the undoped polyaniline (conductive polymer)
A film was formed to a thickness of 50 nm by spin coating using a% N-methylpyrrolidone solution, and a layer 3 made of polyaniline (conductive polymer) was formed to obtain a laminate (a). The laminate is immersed in an aqueous solution (electrolyte solution) of 2% lithium polystyrene sulfonate having a pH of 6, and the current is applied for 20 seconds at a current density of about 5 mA using the ITO electrode 2 with a platinum wire as a counter electrode. The polyaniline 3 ′ on the ITO electrode was doped with polystyrene sulfonate ions (c). This was washed with water and vacuum dried at 60 ° C. for 6 hours. Next, using a 0.4 wt% chloroform solution of polymeric fluorescent substance 1, spin coating was performed to 100 nm.
The light-emitting layer 4 was formed by forming a film having a thickness of 5 nm. Further, this was dried under reduced pressure at 80 ° C. for 1 hour, and then, as a cathode 5, calcium was deposited to a thickness of 25 nm and then aluminum was deposited to a thickness of 40 nm to produce an organic EL device (d). The cathode is IT
It was formed in a band shape with a width of 2 mm in a direction orthogonal to the O electrode.
One pixel is 2m where one of the ITO electrodes and the cathode intersect
It is an area of mx 2 mm. The degree of vacuum at the time of vapor deposition was 1 to 8 × 10 ⁻⁶ Torr in all cases. 1 of the obtained element
By applying a voltage between the two ITO electrodes and the cathode, EL light emission from the polymer phosphor 1 was obtained. The range of light emission is 2 mm x 2 where the ITO electrode and the cathode overlap.
mm only. The light emission starting voltage was about 3 V, and the light emission efficiency was 0.64 cd / A at the maximum.

Comparative Example 1 After forming a polyaniline thin film, a device was prepared in the same manner as in Example 1 except that the entire surface was doped by immersion in an aqueous solution of polystyrene sulfonic acid at pH 1. By applying a voltage between one of the ITO electrodes and the cathode of the obtained device, EL light emission from the polymeric fluorescent substance 1 was obtained. However, light was emitted not only in the area where the ITO electrode and the cathode overlap but also in the surrounding area. Although the light-emission starting voltage was about 2.5 V, the light-emission efficiency could not be converted because non-uniform light-emission also occurred in portions other than on the ITO electrode.

[0081]

According to the manufacturing method of the present invention, an organic EL element having a layer containing a conductive polymer and having a small leak current between adjacent pixels even when the pixel pitch is small can be easily obtained. be able to. Furthermore, since the manufacturing method of the present invention uses electrochemical doping, the amount of doping can be controlled by the amount of electricity to be supplied, so that the electrical characteristics of the device can be finely controlled.
Further, the organic EL element of the present invention has the above-mentioned excellent characteristics, and is preferably used for a display device such as a curved or planar light source for backlight or illumination, and a segment type or dot matrix flat panel display. Can be used.

[Brief description of the drawings]

FIG. 1 is a process sectional view showing Example 1 of the present invention.

[Explanation of symbols]

1: glass substrate 2: ITO electrode 3: polyaniline (conductive polymer) 3 ′: doped polyaniline (doped conductive polymer) 4: polymeric fluorescent substance (organic light emitting substance) 5: metal electrode

Claims (9)

[Claims] 1. A method of manufacturing an organic electroluminescent device having at least one transparent or translucent pair of an anode and a cathode, comprising at least a layer containing a conductive polymer and a light emitting layer containing an organic light emitting material. The method for producing an organic electroluminescent device according to any one of the preceding claims, comprising the following steps (A) and (B): (A) over a substrate having an electrode formed in a desired pattern, covering the electrode, (a) forming a layer containing a undoped conductive polymer, or (b) forming a conductive polymer. Forming a layer containing, and dedoping the conductive polymer to form a laminate, (B) substantially no doping of the laminate with ions for doping the conductive polymer occurs. The electrode is immersed in an electrolyte solution containing the ions adjusted to the acidity, and the electrolyte is electrochemically applied to the conductive polymer by applying an electric current to the electrolyte solution using the electrode formed in the desired pattern. A step of doping ions; 2. The conductive polymer comprises polyaniline and its derivative, polythiophene and its derivative, polypyrrole and its derivative, polyarylenevinylene and its derivative, polyquinoline and its derivative, polyquinoxaline and its derivative, and aromatic amine structure. The method for producing an organic electroluminescence device according to claim 1, wherein the device is selected from the group consisting of a polymer containing the same. 3. The method according to claim 1, wherein at least one of the ions doped into the layer containing the conductive polymer is a polymer ion having a polystyrene equivalent number average molecular weight of 10 ³ to 10 ^7. A method for producing the organic electroluminescence device according to the above. 4. The organic electroluminescent device according to claim 1, wherein at least one kind of ions doped in the layer containing the conductive polymer is an ionic dye. Method. 5. A method according to claim 1, wherein the light-emitting layer comprises at least one kind of a repeating unit represented by the following formula (1) as an organic light-emitting material; An organic electroluminescent device comprising a polymeric fluorescent substance having a total of repeating units of 50 mol% or more and 100 mol% or less of all repeating units, and having a polystyrene equivalent number average molecular weight of 10 ³ to 10 ⁸ . Embedded image -Ar _1- (CR ₁ = CR ₂ ) _n- (1) [where Ar ₁ is an arylene having 6 to 60 carbon atoms contained in the main chain portion. It is a divalent heterocyclic compound group having from 4 to 60 carbon atoms contained in the group or the main chain, and may be unsubstituted or have one or more substituents. R ₁ and R ₂ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms, a heterocyclic compound group having 4 to 60 carbon atoms, and a cyano group. Represents a group. The aryl group and the heterocyclic compound group may further have a substituent. n is 0 or 1. ] 6. A planar light source using the organic electroluminescence device according to claim 5. 7. A segment display device using the organic electroluminescence element according to claim 5. 8. A dot matrix display device using the organic electroluminescence device according to claim 5. 9. A liquid crystal display device, wherein the organic electroluminescence element according to claim 5 is used as a backlight.