JP4994426B2 - Organic electroluminescence element and display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent device improved in luminous efficiency. <P>SOLUTION: The electroluminescent device 1 has a light-emitting layer 14 between a pair of electrodes: a positive electrode 12 and a negative electrode 17. An electron-injection layer 16 and an electron transport-suppressing layer 15 are provided between the negative electrode 17 and the light-emitting layer 14, thereby adjusting the quantity of electrons supplied to the light-emitting layer 14. The electron mobility of the electron injection-suppressing layer 15 is smaller than that of the electron injection layer 16; and the electron mobility of the electron injection layer 16 is larger than that of tris(8-quinolinolato)aluminum complex. The electron injection layer 16 comprises a compound of HAr-L<SP>3</SP>-Ar<SP>7</SP>-Ar<SP>8</SP>. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an organic electroluminescence element and a display device using the same.

  An organic electroluminescence element (hereinafter abbreviated as “EL”) is highly visible due to self-emission and is a completely solid element, and therefore has features such as excellent impact resistance. The use as a light emitting element in various display devices has attracted attention.

  In an organic EL element, a light emitting layer is sandwiched between a pair of electrodes composed of an anode and a cathode, and when an electric field is applied between both electrodes, electrons are injected from the cathode side into the light emitting layer, and the light emitting layer is formed from the anode side. When holes are injected into the light emitting layer, electrons and holes are recombined in the light emitting layer to emit light.

Techniques for increasing the efficiency of organic EL elements include a technique for doping a light emitting layer, improvement of a cathode material, and the like, and improvement of current efficiency is achieved.
On the other hand, in order to reduce power consumption, a voltage reduction technique has been developed, and it has been confirmed that an organic EL element is significantly reduced in voltage by using an organic material having high electron or hole mobility.
However, realizing both high current efficiency and low voltage at the same time is not always easily achieved. Furthermore, it is very difficult to achieve a long life at the same time.
In particular, it is very difficult for an organic EL element that develops blue color, and it is not always sufficient even though various improvements have been made so far.

The use of a hole blocking layer has been proposed as a technique for reducing the voltage with high efficiency (see, for example, Patent Document 1). The hole blocking layer is a layer provided to prevent holes injected into the light emitting layer from diffusing in the cathode direction. However, when the light emitting layer has a wide gap, such as blue light emission, the ionization potential is increased, and therefore the ionization potential of the hole blocking layer to be combined therewith must be further increased. As a result, it is difficult to select a material and the lifetime is often short, so that it has not been put into practical use.
Further, in order to adjust the ratio of blocking holes, it is necessary to select different hole blocking materials. When the light emitting layers are different, it is necessary to select a hole blocking material according to the materials.

  Incidentally, it has been reported that an electron injection layer has a very high electron mobility, and it has been confirmed that the organic EL element can be remarkably reduced in voltage by using these layers (for example, Patent Document 2, Patent Document). 3). However, in this case, since the amount of electrons injected into the light emitting layer is excessive as compared with the amount of holes, the ratio of electrons passing through the light emitting layer is often increased. Therefore, since the current is a combination of the flow of holes and electrons, a large amount of current flows, but the amount of light emission does not increase so much. That is, there is a problem that sufficient luminous efficiency cannot be obtained and the lifetime is short.

Japanese Patent Laid-Open No. 2-195683 Japanese Patent Laid-Open No. 9-087616 JP-A-9-194487

In view of this problem, an object of the present invention is to provide an organic EL element with improved luminous efficiency.
In particular, an object is to provide an organic EL device having a low voltage and high luminous efficiency.

  In order to solve the above problems, the present inventors have intensively researched and found that current cannot be efficiently converted into light unless the amount of holes and electrons injected into the light emitting layer is balanced. . That is, when electrons are excessive with respect to holes, it has been found that it is very effective to suppress the excess electrons and balance the holes and electrons. Thus, unless the holes and electrons are balanced, even if a very excellent material is used for the light emitting layer, the performance cannot be sufficiently exhibited.

  However, fine adjustment is required to balance the holes and electrons. Electrical conductivity in organic materials is different from metals and semiconductors, so it does not follow Ohm's law, and has a characteristic that current flows suddenly from a threshold voltage, and the current is proportional to the power of the voltage. In general, a current flowing through an insulator such as an organic material is called a space charge limited current. This characteristic is not usually the same for holes and electrons, so it is very difficult to balance holes and electrons.

In order to maintain such a delicate balance, in order to adjust the balance by using various materials for holes and electrons, and adjusting the balance, it is necessary to consider a huge combination of materials. Therefore, it takes a lot of time.
On the other hand, the adjustment by changing the material is performed by changing the molecular structure of the material. However, it is generally difficult to change the material slightly to obtain an arbitrary mobility.

  Therefore, the present inventors have found that the balance between the amount of holes and electrons injected into the light emitting layer can be easily adjusted by forming a hole or electron injection suppressing layer between the electrode and the light emitting layer. It was.

That is, according to the present invention, an organic EL device having a light emitting layer between an anode and a cathode, which are a pair of electrodes, and the amount of electrons or holes supplied to the light emitting layer between the electrode and the light emitting layer. Provided is an organic EL element characterized in that a suppression layer for adjusting the thickness is provided.
In this element, since the balance between the amount of holes and electrons injected into the light emitting layer can be adjusted by the suppression layer, the performance of the light emitting material can be maximized. Therefore, in order to control the balance between holes and electrons, it is not necessary to change the materials such as the hole injection layer and the electron injection layer, and the balance can be controlled relatively easily. Very good.

Specifically, when the amount of electrons injected into the light emitting layer is excessive with respect to the holes, the electron injection layer is interposed between the cathode and the light emitting layer, and the electron injection is smaller than the electron injection layer. By providing the suppression layer, the amount of electrons injected into the light emitting layer is suppressed and the balance with the holes is adjusted.
For example, a material in which electrons are excessive in the electron injection layer alone and a material in which holes are excessive in the electron injection suppression layer alone are selected, and an electron injection suppression layer is inserted between the light emitting layer and the film thickness is reduced to 0. As the thickness gradually increases, the amount of holes and electrons is balanced at a certain thickness, and the current efficiency reaches the maximum value.
Thus, in the present invention, it is possible to adjust the electron injection amount steplessly only by changing the film thickness of the electron injection suppression layer.

  Similarly, when the amount of holes is excessive, a light-emitting layer is provided by providing a hole-injection layer and a hole-injection suppression layer having a hole mobility smaller than that of the hole-injection layer between the anode and the light-emitting layer The amount of holes injected into the surface is suppressed to balance with electrons.

The present invention is a very effective technique for blue light emission. Blue light emitting materials have high energy and a relatively large energy gap. Therefore, when the hole transport layer and the light emitting layer are combined and recombination in the light emitting layer is concentrated at the interface, the difference between the affinity level of the light emitting layer and the hole transport layer tends to be small, It can be said that it is easy to enter the hole transport layer from the light emitting layer. Therefore, it is necessary to finely adjust the injection balance of holes and electrons as compared with the light emitting layer emitting other colors.
In addition, the light emitting layer is often doped, and the carrier balance can be changed by the dopant. However, in the case of a light emitting layer that emits blue light, the dopant does not act strongly as a trap, so it is very difficult to improve the balance with only the blue dopant when there is an excess of electrons.
On the other hand, the present invention adjusts the balance according to the film thickness of the electron injection suppressing layer, and has an excellent advantage that it can be applied regardless of the material used for the light emitting layer.

Such insertion of the suppression layer is very effective because the balance between holes and electrons can be improved by a relatively simple method, and because of its simplicity, it is powerful and very excellent as a practical technique.
The present applicant has previously as mobility is extremely high electron injection layer of the electrophotographic proposes a novel nitrogen-containing cyclic compounds (Japanese Patent Application No. 2003-0041 39 No.).
By combining such a material having a high electron mobility and the electron injection suppressing layer of the present invention, an organic EL element having a low voltage and a high luminous efficiency can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the organic EL element which improved the luminous efficiency can be provided.

It is sectional drawing of the organic EL element of one Embodiment of this invention. It is an energy diagram of the organic EL element of one Embodiment of this invention.

Hereinafter, the present invention will be described in detail.
First, the organic EL element of this invention is demonstrated using drawing.
FIG. 1 is a cross-sectional view of an organic EL device according to an embodiment of the present invention, and FIG. 2 is an energy diagram of the EL device.
This embodiment is an example in which an electron injection suppression layer is provided because there are more electrons supplied from the electron injection layer than holes supplied from the hole injection layer.

  As a combination of such materials, there is a combination in which the electron injection layer is ET1, the hole injection layer is α-NPD, and the electron injection suppression layer is Alq. These chemical formulas are shown below.

  The organic EL element 1 has a structure in which an anode 12, a hole injection layer 13, a light emitting layer 14, an electron injection suppression layer 15, an electron injection layer 16, and a cathode 17 are laminated on a substrate 11 in this order.

  The substrate 11 is a substrate that supports the organic EL element. The anode 12 plays a role of injecting holes into the hole injection layer 13 or the light emitting layer 14. The hole injection layer 13 is a layer that assists hole injection into the light emitting layer 14 and transports it to the light emitting region. The light emitting layer 14 mainly provides a field for recombination of electrons and holes, and connects this to light emission. The electron injection suppression layer 15 is a layer for adjusting injection of electrons into the light emitting layer 14 and balancing with holes. The electron injection layer 16 is a layer that assists injection of electrons into the light emitting layer 14. The cathode 17 serves to inject electrons into the electron injection layer 16 or the light emitting layer 14.

In the present embodiment, the function of injecting electrons into the light emitting layer 14 needs to be lower than that of the electron injection layer 16 in order to exhibit the function of the electron injection suppression layer 15.
As such a thing, the thing whose electron mobility is lower than the electron injection layer 16, or a thing with a large affinity level is mentioned, for example.

Electron mobility is the ratio of the applied electric field to the velocity of electrons. If the electric field is strong, the velocity of electrons increases and the current increases.
In the organic EL element in which the total film thickness of the electron injection suppression layer 15 and the electron injection layer 16 is constant, when a constant voltage is applied while changing the film thickness ratio of the electron injection suppression layer 15 and the electron injection layer 16, By inserting a material with low mobility as the electron injection suppression layer 15, the electric field generated in the electron injection layer 16 can be made smaller than when the electron injection suppression layer 15 is not provided. Further, the thicker the electron injection suppression layer 15 is, the smaller the electric field generated in the electron injection layer 16 is.
Therefore, the electric field of the electron injection layer 16 can be controlled by the film thickness of the electron injection suppression layer 15, whereby the current caused by electrons, that is, the amount of electrons injected into the light emitting layer 14 can be adjusted.

Further, by adjusting the affinity levels of the light emitting layer 14, the electron injection suppressing layer 15, and the electron injection layer 16, the balance of holes and electrons injected into the light emitting layer 14 can be controlled.
The affinity level means the level of the electron conduction level of each layer in the energy diagram shown in FIG. 2 and corresponds to the LUMO (lowest unoccupied molecular orbital) energy level of the constituent molecules.
When the affinity level Af2 of the electron injection suppression layer 15 is greater than the affinity level Af1 of the light emitting layer 14, and the affinity level Af2 of the electron injection suppression layer 15 is greater than or equal to the affinity level Af3 of the electron injection layer 16 That is, when the relationship of Af1 <Af2 and Af3 ≦ Af2 is satisfied, an injection barrier corresponding to the difference in affinity level exists in the injection of electrons from the electron injection suppression layer 15 to the light emitting layer 14.
Thus, the electron injection into the light emitting layer 14 can be controlled by forming the injection barrier.

  Note that the amount of electrons injected into the light emitting layer 14 can be adjusted by either electron mobility or affinity level, or may be adjusted by using both.

In addition to the above, the configuration of the organic EL element of the present invention is, for example,
i) Anode / light emitting layer / electron injection suppression layer / electron injection layer / cathode
ii) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection suppression layer
/ Electron injection layer / Cathode
iii) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection suppression layer
/ Electron transport layer / electron injection layer / cathode
iv) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer
/ Electron injection suppression layer / electron injection layer / cathode
v) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer
/ Electron injection suppression layer / electron injection layer / adhesion improving layer / cathode
vi) Anode / organic semiconductor layer / light emitting layer / electron injection suppression layer / electron injection layer / cathode
vii) Anode / organic semiconductor layer / hole injection layer / light emitting layer / electron injection suppression layer
/ Electron injection layer / Cathode
viii) Anode / organic semiconductor layer / hole injection layer / hole transport layer / light emitting layer
/ Electron injection suppression layer / electron injection layer / cathode
ix) Anode / organic semiconductor layer / hole injection layer / hole transport layer / light emitting layer
/ Electron injection suppression layer / electron transport layer / electron injection layer / cathode
x) Anode / insulating layer / light emitting layer / electron injection suppression layer / electron injection layer / cathode
xi) Anode / inorganic semiconductor layer / insulating layer / light emitting layer / electron injection suppression layer
/ Electron injection layer / cathode and the like. Hereinafter, each layer which comprises the organic EL element of this invention is demonstrated.
In addition, unless the effect of this invention is impaired, another organic layer or an inorganic layer can be interposed between said each layer.
Further, when the amount of holes injected into the light emitting layer is larger than that of electrons, a hole injection suppressing layer is formed between the anode and the light emitting layer instead of the electron injection suppressing layer in the above configuration.

(1) Translucent substrate The organic EL element of this invention is produced on a translucent board | substrate. Here, the translucent substrate is a substrate that supports the organic EL element, and is preferably a smooth substrate having a transmittance of 50% or more in visible light of 400 to 700 nm.
Specifically, a glass plate, a polymer plate, etc. are mentioned. Examples of the glass plate include soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.

(2) Anode The anode of the organic thin film EL element plays a role of injecting holes into the hole transport layer or the light emitting layer, and it is effective to have a work function of 4.5 eV or more. Specific examples of the anode material used in the present invention include indium tin oxide alloy (ITO), zinc oxide tin alloy (IZO), tin oxide (NESA), gold, silver, platinum, copper, and the like.
The anode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.
Thus, when light emission from the light emitting layer is taken out from the anode, it is preferable that the transmittance of the anode for light emission is greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. Although the film thickness of the anode depends on the material, it is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

(3) Hole injection and transport layer The hole injection and transport layer is a layer that assists hole injection into the light emitting layer and transports it to the light emitting region, and has a high hole mobility and usually has an ionization energy of 5.5 eV. The following is small. As such a hole injection and transport layer, a material that transports holes to the light emitting layer with a lower electric field strength is preferable, and further, when a hole mobility is, for example, an electric field of 10 ⁴ to 10 ⁶ V / cm, It is preferable if it is at least 10 ⁻⁴ cm ² / V · sec.
The material for forming the hole injecting and transporting layer is not particularly limited as long as it has the above-mentioned preferred properties, and conventionally used as a charge transporting material for holes in an optical transmission material, or an EL element. Any of known materials used for the hole injection layer can be selected and used.

  Specific examples include, for example, triazole derivatives (see U.S. Pat. No. 3,112,197), oxadiazole derivatives (see U.S. Pat. No. 3,189,447), imidazole derivatives (Japanese Patent Publication No. 37-16096). Polyarylalkane derivatives (US Pat. Nos. 3,615,402, 3,820,989, 3,542,544, and JP-B-45-555). JP, 51-10983, JP-A-51-93224, 55-17105, 56-4148, 55-108667, 55-156953, 56-36656 No. 3,180,729, US Pat. No. 4,278,746, pyrazoline derivatives and pyrazolone derivatives (see US Pat. Nos. 3,180,729 and 4,278,746). JP, 55-88064, 55-88065, 49-105537, 55-51086, 56-80051, 56-88141, 57-45545. Gazette, 54-112737, 55-74546, etc.), phenylenediamine derivatives (US Pat. No. 3,615,404, JP-B 51-10105, 46-3712, 47-25336, JP-A 54-53435, 54-110536, 54-1119925, etc.), arylamine derivatives (US Pat. No. 3,567,450), 3,180,703, 3,240,597, 3,658,520, 4,232,1 No. 3, No. 4,175,961, No. 4,012,376, JP-B No. 49-35702, No. 39-27577, JP-A No. 55-144250 56-119132, 56-22437, West German Patent 1,110,518, etc.), amino-substituted chalcone derivatives (see US Pat. No. 3,526,501, etc.), Oxazole derivatives (disclosed in US Pat. No. 3,257,203, etc.), styryl anthracene derivatives (see JP 56-46234 A, etc.), fluorenone derivatives (see JP 54-110837 A, etc.) ), Hydrazone derivatives (US Pat. No. 3,717,462, JP-A-54-59143, 55-52063, 55-52064). No. 55-46760, No. 55-85495, No. 57-11350, No. 57-148799, JP-A-2-311591, etc.), Stilbene derivatives (JP-A 61-61). No. 210363, No. 61-228451, No. 61-14642, No. 61-72255, No. 62-47646, No. 62-36674, No. 62-10652, No. 62- 30255, 60-94455, 60-94462, 60-174749, 60-175052, etc.), silazane derivatives (US Pat. No. 4,950,950) , Polysilanes (JP-A-2-204996), aniline copolymers (JP-A-2-282263), JP-A-1 Conductive polymer oligomers disclosed in 211399 JP can (particularly thiophene oligomer).

  Although the above-mentioned materials can be used as the material for the hole injection layer, porphyrin compounds (disclosed in JP-A-63-295965), aromatic tertiary amine compounds and styrylamine compounds (US) Patent No. 4,127,412, JP-A-53-27033, 54-58445, 54-149634, 54-64299, 55-79450, 55 No. 144450, No. 56-119132, No. 61-295558, No. 61-98353, No. 63-295695, etc.), in particular, an aromatic tertiary amine compound is preferably used.

In addition, for example, 4,4′-bis (N- (1-naphthyl) -N-phenylamino having two condensed aromatic rings described in US Pat. No. 5,061,569 in the molecule. ) Biphenyl (hereinafter abbreviated as NPD), and 4,4 ′, 4 ″ -tris (N—) in which three triphenylamine units described in JP-A-4-308688 are linked in a starburst type. (3-methylphenyl) -N-phenylamino) triphenylamine (hereinafter abbreviated as MTDATA) and the like.
In addition to the above-described aromatic dimethylidin compounds shown as the material for the light emitting layer, inorganic compounds such as p-type Si and p-type SiC can also be used as the material for the hole injection layer.

The hole injection and transport layer can be formed by thinning the above-described compound by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. The thickness of the hole injection or transport layer is not particularly limited, but is usually 5 nm to 5 μm. As long as this hole injection and transport layer contains the compound of the present invention in the hole transport zone, it may be composed of one or more of the above materials, or the hole injection, A layer in which a hole injection / transport layer made of a compound different from the transport layer is laminated may be used.
The organic semiconductor layer is a layer that assists hole injection or electron injection into the light emitting layer, and preferably has a conductivity of 10 ⁻¹⁰ S / cm or more. As a material for such an organic semiconductor layer, a conductive oligomer such as a thiophene-containing oligomer, an arylamine oligomer disclosed in JP-A-8-193191, a conductive dendrimer such as an arylamine dendrimer, or the like is used. Can do.

(4) Hole injection suppression layer The material used for the hole injection suppression layer is a material that suppresses holes, but must not be a material that does not allow holes to flow. Such a material is conventionally used for a hole injection layer and has a lower hole mobility or ionization potential than the hole injection layer used in the organic EL device of the present invention. A small material can be used.
Specifically, JP-A-5-234678, JP-A-5-320634, JP-A-6-220437, JP-B-2686418, JP-B-2924809, JP-A-7-138562, JP-A-7-138562, The diamine compounds described in Kaihei 11-54280, JP-A-7-157454, JP-A-10-316658, European Publication 0650955A1, JP-A 2002-249765, JP-A-3- The amine derivatives described in, for example, No. 111485 and JP-A-6-329881 are preferred.

(5) Light emitting layer The light emitting layer has the following functions.
1. Injection function: a function capable of injecting holes from the anode or the hole injection layer when an electric field is applied and a function of injecting electrons from the cathode or the electron injection layer. 2. Transport function; function of moving injected charges (electrons and holes) by the force of an electric field Light emitting function; a function to provide a field for recombination of electrons and holes and connect it to light emission. However, there may be a difference between the ease of hole injection and the ease of electron injection. Although the transport ability represented by the mobility of electrons may be large or small, it is preferable to transfer one of the charges.

  As the host material used for the light-emitting layer, a known material can be used as a long-life light-emitting material, but a material represented by the following formula [1] is preferably used as the host material of the light-emitting material. However, it is not necessarily limited to the following materials.

（式中、Ａｒ^１は核炭素数６〜５０の芳香族環であり、Ｘ^１は置換基である。ｌは１〜５の整数、ｍは０〜６の整数である。尚、ｌ≧２のとき、Ａｒ^１はそれぞれ同じでも異なっていてもよく、ｍ≧２のとき、Ｘ^１はそれぞれ同じでも異なっていても良い。ｌは１〜２、ｍは０〜４が好ましい。）

(In the formula, Ar ¹ is an aromatic ring having 6 to 50 nuclear carbon atoms, X ¹ is a substituent, l is an integer of 1 to 5, and m is an integer of 0 to 6. Here, l ≧ Ar ² may be the same or different when 2, and when m ≧ 2, X ¹ may be the same or different. L is preferably 1 to 2, and m is preferably 0 to 4.)

Specific examples of the aromatic ring of Ar ¹ include phenyl ring, naphthyl ring, anthracene ring, biphenylene ring, azulene ring, acenaphthylene ring, fluorene ring, phenanthrene ring, fluoranthene ring, acephenanthrylene ring, triphenylene ring, pyrene ring, Examples include a chrysene ring, a naphthacene ring, a picene ring, a perylene ring, a pentaphen ring, a pentacene ring, a tetraphenylene ring, a hexaphen ring, a hexacene ring, a rubicene ring, a coronene ring, and a trinaphthylene ring.
Preferred examples include phenyl ring, naphthyl ring, anthracene ring, acenaphthylene ring, fluorene ring, phenanthrene ring, fluoranthene ring, triphenylene ring, pyrene ring, chrysene ring, perylene ring, trinaphthylene ring and the like.
More preferable examples include a phenyl ring, a naphthyl ring, an anthracene ring, a fluorene ring, a phenanthrene ring, a fluoranthene ring, a pyrene ring, a chrysene ring, and a perylene ring.

Specific examples of X ¹ include a substituted or unsubstituted aromatic group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nuclear atoms, a substituted or unsubstituted carbon number of 1 to 1 50 alkyl groups, substituted or unsubstituted alkoxy groups having 1 to 50 carbon atoms, substituted or unsubstituted aralkyl groups having 1 to 50 carbon atoms, substituted or unsubstituted aryloxy groups having 5 to 50 nuclear atoms, substituted Or an unsubstituted arylthio group having 5 to 50 nuclear atoms, a substituted or unsubstituted carboxyl group having 1 to 50 carbon atoms, a substituted or unsubstituted styryl group, a halogen group, a cyano group, a nitro group, a hydroxyl group, etc. .

  Examples of the substituted or unsubstituted aromatic group having 6 to 50 nuclear carbon atoms include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1 -Phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4 -Pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl Group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, -T-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4'-methylbiphenyl Yl group, 4 "-t-butyl-p-terphenyl-4-yl group, 2-fluorenyl group, 9,9-dimethyl-2-fluorenyl group, 3-fluoranthenyl group and the like.

  Preferably, phenyl group, 1-naphthyl group, 2-naphthyl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, o-tolyl group, m-tolyl group, p-tolyl group, pt-butylphenyl group, 2-fluorenyl group, 9,9 -A dimethyl- 2-fluorenyl group, 3-fluoranthenyl group, etc. are mentioned.

  Examples of the substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nucleus atoms include 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, and 3-pyridinyl group. 4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 2-isoindolyl group 3-isoindolyl group, 4-isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuran group Nyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolyl group, 5- Quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8- Isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 1-phenanthridinyl group 2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group Ensridinyl group, 8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group Group, 1,7-phenanthrolin-2-yl group, 1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5 -Yl group, 1,7-phenanthrolin-6-yl group, 1,7-phenanthrolin-8-yl group, 1,7-phenanthrolin-9-yl group, 1,7-phenanthroline -10-yl group, 1,8-phenanthrolin-2-yl group, 1,8-phenanthrolin-3-yl group, 1,8-phenanthrolin-4-yl group, 1,8-phen group Nansulolin-5-yl group, 1,8-phen Nansulolin-6-yl group, 1,8-phenanthrolin-7-yl group, 1,8-phenanthrolin-9-yl group, 1,8-phenanthrolin-10-yl group, 1,9- Phenanthrolin-2-yl group, 1,9-phenanthrolin-3-yl group, 1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group, 1, 9-phenanthroline-6-yl group, 1,9-phenanthrolin-7-yl group, 1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group, 1,10-phenanthrolin-2-yl group, 1,10-phenanthrolin-3-yl group, 1,10-phenanthrolin-4-yl group, 1,10-phenanthrolin-5-yl Group, 2,9-phenanthrolin-1-yl group, 2,9-phenanthro -3-yl group, 2,9-phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group, 2,9- Phenanthrolin-7-yl group, 2,9-phenanthrolin-8-yl group, 2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group, 2, 8-phenanthroline-3-yl group, 2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl group, 2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl group, 2,7-phenanthrolin-1-yl Group, 2,7-phenanthrolin-3-yl group, 2,7-phenanthrolin-4-yl group 2,7-phenanthrolin-5-yl group, 2,7-phenanthrolin-6-yl group, 2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl Group, 2,7-phenanthrolin-10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 10 -Phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group, 3-phenoxazinyl group, 4-phenoxazinyl group, 10-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-furazanyl group, 2-thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl group, 3- (2-phenylpropyl) pyrrol-1-yl group, 2-methyl -1-Indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolyl group, 2-t-butyl 1-indolyl group, 4-t-butyl 1- Indolyl group, 2-t-butyl 3-indolyl group, 4-t-butyl 3-indolyl group and the like can be mentioned.

  Examples of the substituted or unsubstituted alkyl group having 1 to 50 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n- Pentyl group, n-hexyl group, n-heptyl group, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl group, 1,2-dihydroxyethyl group, 1, 3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group, 2-chloroethyl group, 2-chloroisobutyl group, 1, 2-dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, 1,2,3-trichloropropyl group Bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group, 1,2, 3-tribromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group, 2,3-diiodo-t- Butyl group, 1,2,3-triiodopropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1,2-diaminoethyl group, 1,3-diaminoisopropyl Group, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group, cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl group, nitromethyl group, 1- Nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t-butyl group, 1,2,3-trinitropropyl Group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 4-methylcyclohexyl group, 1-adamantyl group, 2-adamantyl group, 1-norbornyl group, 2-norbornyl group and the like.

  A substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms is a group represented by -OY, and examples of Y include methyl, ethyl, propyl, isopropyl, n-butyl, and s-butyl. Group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl Group, 1,2-dihydroxyethyl group, 1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group, 2 -Chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, , 2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1,3-dibromoisopropyl group, 2,3-dibromo- t-butyl group, 1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group 2,3-diiodo-t-butyl group, 1,2,3-triiodopropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1,2-diamino Ethyl group, 1,3-diaminoisopropyl group, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group, cyanomethyl group, 1- Anoethyl group, 2-cyanoethyl group, 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl Group, nitromethyl group, 1-nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t-butyl group, 1, Examples include 2,3-trinitropropyl group.

Examples of the substituted or unsubstituted aralkyl group having 1 to 50 carbon atoms include benzyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenylisopropyl group, 2-phenylisopropyl group, and phenyl-t-butyl. Group, α-naphthylmethyl group, 1-α-naphthylethyl group, 2-α-naphthylethyl group, 1-α-naphthylisopropyl group, 2-α-naphthylisopropyl group, β-naphthylmethyl group, 1-β- Naphthylethyl group, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group, 2-β-naphthylisopropyl group, 1-pyrrolylmethyl group, 2- (1-pyrrolyl) ethyl group, p-methylbenzyl group, m -Methylbenzyl group, o-methylbenzyl group, p-chlorobenzyl group, m-chlorobenzyl group, o-chlorobenzyl group, p-bromoben Group, m-bromobenzyl group, o-bromobenzyl group, p-iodobenzyl group, m-iodobenzyl group, o-iodobenzyl group, p-hydroxybenzyl group, m-hydroxybenzyl group, o-hydroxybenzyl group ,
p-aminobenzyl group, m-aminobenzyl group, o-aminobenzyl group, p-nitrobenzyl group, m-nitrobenzyl group, o-nitrobenzyl group, p-cyanobenzyl group, m-cyanobenzyl group, o- A cyanobenzyl group, 1-hydroxy-2-phenylisopropyl group, 1-chloro-2-phenylisopropyl group and the like can be mentioned.

  A substituted or unsubstituted aryloxy group having 5 to 50 nuclear atoms is represented as -OY ', and examples of Y' include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, and a 2-anthryl group. Group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl Group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, -Tolyl group, p-tolyl group, pt-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl- 1-anthryl group, 4′-methylbiphenylyl group, 4 ″ -t-butyl-p-terphenyl-4-yl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3- Pyridinyl group, 4-pyridinyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 3-isoindolyl group, 4- Isoindolyl group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group Nyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8 -Quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6 -Quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 1-phenanthridinyl Group, 2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phenanthridinyl group, 9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, 1,7-phenanthroline-2 -Yl group, 1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5-yl group, 1,7-phenanthroline -6-yl group, 1,7-phenanthrolin-8-yl group, 1,7-phenanthrolin-9-yl group, 1,7-phenanthrolin-10-yl group, 1,8-phen group Nansulolin-2-yl group, 1,8- Phenanthrolin-3-yl group, 1,8-phenanthrolin-4-yl group, 1,8-phenanthrolin-5-yl group, 1,8-phenanthrolin-6-yl group, 1,8- Phenanthrolin-7-yl group, 1,8-phenanthroline-9-yl group, 1,8-phenanthrolin-10-yl group, 1,9-phenanthrolin-2-yl group, 1, 9-phenanthrolin-3-yl group, 1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group, 1,9-phenanthrolin-6-yl group, 1,9-phenanthrolin-7-yl group, 1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group, 1,10-phenanthrolin-2-yl Group, 1,10-phenanthrolin-3-yl group, 1,10-phenanth Rin-4-yl group, 1,10-phenanthrolin-5-yl group, 2,9-phenanthrolin-1-yl group, 2,9-phenanthrolin-3-yl group, 2,9- Phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group, 2,9-phenanthrolin-7-yl group, 2, 9-phenanthroline-8-yl group, 2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group, 2,8-phenanthrolin-3-yl group, 2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl Group, 2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl Group, 2,7-phenanthrolin-1-yl group, 2,7-phenanthrolin-3-yl group, 2,7-phenanthrolin-4-yl group, 2,7-phenanthrolin-5 -Yl group, 2,7-phenanthroline-6-yl group, 2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl group, 2,7-phenanthroline -10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group, 3-phenoxazinyl group, 4-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-flazanyl group 2-thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl Group, 3- (2-phenylpropyl) pyrrol-1-yl group, 2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3- Indolyl group, 2-t-butyl 1-indolyl group, 4-t-butyl 1-indolyl group, 2-t-butyl 3-indolyl group, 4-t-butyl 3-indolyl group and the like can be mentioned.

  A substituted or unsubstituted arylthio group having 5 to 50 nuclear atoms is represented by —SY ″, and examples of Y ″ include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, and a 2-anthryl group. 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p -Terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m Tolyl group, p-tolyl group, pt-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1 -Anthryl group, 4'-methylbiphenylyl group, 4 "-t-butyl-p-terphenyl-4-yl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl Group, 4-pyridinyl group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group Group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuranyl group, 5-isobenzofuranyl group Group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8- Quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6- Quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 1-phenanthridinyl group 2-phenanthridinyl group, 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phenanthridinyl group, 9 -Phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, 1,7-phenanthroline-2- Yl group, 1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5-yl group, 1,7-phenanthrolin- 6-yl group, 1,7-phenanthroline-8-yl group, 1,7-phenanthrolin-9-yl group, 1,7-phenanthrolin-10-yl group, 1,8-phenance Lorin-2-yl group, 1,8-Fu Nansulolin-3-yl group, 1,8-phenanthrolin-4-yl group, 1,8-phenanthrolin-5-yl group, 1,8-phenanthrolin-6-yl group, 1,8- Phenanthrolin-7-yl group, 1,8-phenanthroline-9-yl group, 1,8-phenanthrolin-10-yl group, 1,9-phenanthrolin-2-yl group, 1, 9-phenanthrolin-3-yl group, 1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group, 1,9-phenanthrolin-6-yl group, 1,9-phenanthrolin-7-yl group, 1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group, 1,10-phenanthrolin-2-yl Group, 1,10-phenanthrolin-3-yl group, 1,10-phenanthro N-4-yl group, 1,10-phenanthrolin-5-yl group, 2,9-phenanthrolin-1-yl group, 2,9-phenanthrolin-3-yl group, 2,9- Phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group, 2,9-phenanthrolin-7-yl group, 2, 9-phenanthroline-8-yl group, 2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group, 2,8-phenanthrolin-3-yl group, 2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl Group, 2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl group 2,7-phenanthrolin-1-yl group, 2,7-phenanthrolin-3-yl group, 2,7-phenanthrolin-4-yl group, 2,7-phenanthrolin-5- Yl group, 2,7-phenanthrolin-6-yl group, 2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl group, 2,7-phenanthrolin- 10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 1-phenoxazinyl group, 2-phenoxazinyl group, 3 -Phenoxazinyl group, 4-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-flazanyl group, -Thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3 -Methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl group 3- (2-phenylpropyl) pyrrol-1-yl group, 2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolyl group Group, 2-t-butyl 1-indolyl group, 4-t-butyl 1-indolyl group, 2-t-butyl 3-indolyl group, 4-t-butyl 3-indolyl group and the like.

  A substituted or unsubstituted carboxyl group having 1 to 50 carbon atoms is represented as —COOZ, and examples of Z include methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, and isobutyl groups. , T-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl group, 1, 2-dihydroxyethyl group, 1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group, 2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, 1, , 3-trichloropropyl group, bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1,3-dibromoisopropyl group, 2,3-dibromo-t- Butyl group, 1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group, 2 , 3-Diiodo-t-butyl group, 1,2,3-triiodopropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1,2-diaminoethyl group 1,3-diaminoisopropyl group, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group, cyanomethyl group, 1-sia Ethyl group, 2-cyanoethyl group, 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl Group, nitromethyl group, 1-nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t-butyl group, 1, Examples include 2,3-trinitropropyl group.

Examples of the substituted or unsubstituted styryl group include 2-phenyl-1-vinyl group, 2,2-diphenyl-1-vinyl group, 1,2,2-triphenyl-1-vinyl group, and the like.
Examples of the halogen group include fluorine, chlorine, bromine and iodine.

（式中、Ａｒ^２〜Ａｒ^４は、置換又は無置換の核炭素数６〜５０の芳香族基、置換又は無置換のスチリル基である。ｎは１〜４の整数であり、ｎ≧２の場合、Ａｒ^３、Ａｒ^４はそれぞれ同じでも異なっていても良い。） A dopant may be added to the light emitting layer. As the dopant used, known materials can be used as long-lived light-emitting materials, but it is desirable to use the material represented by the formula [2] as the dopant material of the light-emitting material. However, it is not necessarily limited to the following materials.

(In the formula, Ar ^{2 to} Ar ⁴ are a substituted or unsubstituted aromatic group having 6 to 50 nuclear carbon atoms and a substituted or unsubstituted styryl group. N is an integer of 1 to 4, and n ≧ 2 In this case, Ar ³ and Ar ⁴ may be the same or different.)

  Examples of the substituted or unsubstituted aromatic group having 6 to 50 nuclear carbon atoms include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1- Phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4- Pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group M-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, p t-butylphenyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenylyl Group, 4 "-t-butyl-p-terphenyl-4-yl group, 2-fluorenyl group, 9,9-dimethyl-2-fluorenyl group, 3-fluoranthenyl group and the like.

  Preferably, phenyl group, 1-naphthyl group, 2-naphthyl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, o-tolyl group, m-tolyl group, p-tolyl group, pt-butylphenyl group, 2-fluorenyl group, 9,9 -A dimethyl- 2-fluorenyl group, 3-fluoranthenyl group, etc. are mentioned.

  Examples of the substituted or unsubstituted styryl group include 2-phenyl-1-vinyl group, 2,2-diphenyl-1-vinyl group, 1,2,2-triphenyl-1-vinyl group, and the like.

As a method for forming the light emitting layer, for example, a known method such as an evaporation method, a spin coating method, or an LB method can be applied. The light emitting layer is particularly preferably a molecular deposited film.
Here, the molecular deposition film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidification from a material compound in a solution state or a liquid phase state. Can be classified from a thin film (accumulated film) formed by the LB method according to a difference in an agglomerated structure and a higher-order structure and a functional difference resulting therefrom.
Further, as disclosed in JP-A-57-51781, a binder such as a resin and a material compound are dissolved in a solvent to form a solution, and then this is thinned by a spin coating method or the like. In addition, a light emitting layer can be formed.

(6) Electron injection suppression layer Although the material used for an electron injection suppression layer is a material which suppresses an electron, it should not be a material which does not flow an electron. As such a material, a material that has been conventionally used for an electron injection layer and has a lower electron mobility or a higher affinity level than the electron injection layer used in the organic EL device of the present invention. Can be used.
As such, for example, a metal complex of 8-hydroxyquinoline or a derivative thereof is suitable. Specific examples include metal chelate oxinoid compounds containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline). For example, (8-quinolinolato) aluminum complex (Alq) can be used.

Further, the electron injection suppressing layer is preferably a heterocyclic derivative, for example, a heterocyclic compound in which a 6-membered ring and a 5-membered ring are condensed, such as an imidazole derivative or an imidazopyridine derivative. Furthermore, a nitrogen-containing ring compound, a silicon-containing ring compound, a boron compound, and the like that can be used as an electron injection layer to be described later can also be suitably used.
However, the electron mobility of the electron injection suppression layer is smaller than the electron mobility of the electron injection layer, or the affinity level Af2 of the electron injection suppression layer is larger than the affinity level Af1 of the light emitting layer, and the electron injection suppression. It is important that the affinity level Af2 of the layer is greater than or equal to the affinity level Af3 of the electron injection layer, that is, satisfy the relationship of Af1 <Af2 and Af3 ≦ Af2.

(7) Electron transport layer As a semiconductor constituting the electron transport layer, at least one element of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb and Zn One kind or a combination of two or more kinds of oxides, nitrides or oxynitrides containing Moreover, it is preferable that the inorganic compound which comprises an electron carrying layer is a microcrystal or an amorphous insulating thin film. If the electron transport layer is composed of these insulating thin films, a more uniform thin film is formed, and pixel defects such as dark spots can be reduced. Examples of such inorganic compounds include the alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides, and alkaline earth metal halides described above.

(8) Electron Injection Layer The electron injection layer is a layer that assists the injection of electrons into the light emitting layer and has a high electron mobility.
In order to improve adhesion to the cathode, an adhesion improving layer may be provided separately from the electron injection layer.

(式中、Ａ^１〜Ａ^３は、窒素原子又は炭素原子であり、Ｒは、置換基を有していてもよい炭素数６〜６０のアリール基、置換基を有していてもよい炭素数３〜６０のヘテロアリール基、炭素数１〜２０のアルキル基、炭素数１〜２０のハロアルキル基、炭素数１〜２０のアルコキシ基であり、ｐは０から５の整数であり、ｐが２以上の整数であるとき、複数のＲは互いに同一又は異なっていてもよい。また、隣接する複数のＲ基同士で互いに結合して、置換又は未置換の炭素環式脂肪族環、あるいは、置換又は未置換の炭素環式芳香族環を形成していてもよい。Ａｒ^５は、置換基を有していてもよい炭素数６〜６０のアリール基、置換基を有していてもよい炭素数３〜６０のヘテロアリール基であり、Ａｒ^６は、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のハロアルキル基、炭素数１〜２０のアルコキシ基、置換基を有していてもよい炭素数６〜６０のアリール基、置換基を有していてもよい炭素数３〜６０のヘテロアリール基であり、（ただし、Ａｒ^５、Ａｒ^６のいずれか一方は置換基を有していてもよい炭素数１０〜６０の縮合環基、置換基を有していてもよい炭素数３〜６０のヘテロ縮合環基である）。Ｌ^１、Ｌ^２は、それぞれ単結合、置換基を有していてもよい炭素数６〜６０の縮合環、置換基を有していてもよい炭素数３〜６０のヘテロ縮合環又は置換基を有していてもよいフルオレニレン基である。) As materials for the electron injection layer, the following nitrogen-containing ring compounds, silicon-containing ring compounds, boron compounds, and the like can be preferably used.
The nitrogen-containing ring compounds are preferably those represented by the following formulas [3] to [17].

(In the formula, A ^{1 to} A ³ are a nitrogen atom or a carbon atom, and R is an aryl group having 6 to 60 carbon atoms which may have a substituent, or an optionally substituted carbon. A heteroaryl group having 3 to 60 carbon atoms, an alkyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, and an alkoxy group having 1 to 20 carbon atoms, p is an integer of 0 to 5, and p is When it is an integer of 2 or more, the plurality of R may be the same or different from each other, and bonded to each other by a plurality of adjacent R groups to form a substituted or unsubstituted carbocyclic aliphatic ring, or A substituted or unsubstituted carbocyclic aromatic ring may be formed, and Ar ⁵ may have an optionally substituted aryl group having 6 to 60 carbon atoms or a substituent. heteroaryl group having 3 to 60 carbon atoms, Ar ⁶ is a hydrogen atom, having 1 to 20 carbon atoms An alkyl group, a haloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 60 carbon atoms which may have a substituent, and a carbon number which may have a substituent. A heteroaryl group having 3 to 60, wherein either Ar ⁵ or Ar ⁶ may have a substituent, a condensed ring group having 10 to 60 carbon atoms, or a substituent. L ¹ and L ² each have a single bond or an optionally substituted condensed ring having 6 to 60 carbon atoms or a substituent. A C3-C60 hetero condensed ring or a fluorenylene group which may have a substituent.

  The compound of the above formula [3] can be synthesized by the method described in Japanese Patent Application No. 2003-005184.

(式中、ＨＡｒは、置換基を有していても良い炭素数３〜４０の含窒素複素環であり、Ｌ^３は、単結合、置換基を有していてもよい炭素数６〜６０のアリーレン基、置換基を有していてもよい炭素数３〜６０のヘテロアリーレン基又は置換基を有していてもよいフルオレニレン基であり、Ａｒ^７は、置換基を有していてもよい炭素数６〜６０の２価の芳香族炭化水素基であり、Ａｒ^８は、置換基を有していてもよい炭素数６〜６０のアリール基又は、置換基を有していてもよい炭素数３〜６０のヘテロアリール基である。)

(In the formula, HAr is a nitrogen-containing heterocyclic ring having 3 to 40 carbon atoms which may have a substituent, and L ³ has 6 to 60 carbon atoms which may have a single bond or a substituent. An arylene group, a C3-C60 heteroarylene group which may have a substituent, or a fluorenylene group which may have a substituent, and Ar ⁷ may have a substituent. It is a C6-C60 bivalent aromatic hydrocarbon group, Ar < ⁸ > is the C6-C60 aryl group which may have a substituent, or the carbon which may have a substituent. (It is a heteroaryl group of several 3 to 60.)

The compound of formula [4] can be synthesized by a method described in Japanese Patent Application No. 2003-0041 39 No..

(式中、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ水素原子又は置換基を表す。Ｚ^１は、５又は６員環を形成するに必要な原子群を表す。)

(Wherein R ¹ , R ² and R ³ each represent a hydrogen atom or a substituent. Z ¹ represents an atomic group necessary for forming a 5- or 6-membered ring.)

（式中、Ｘ^１〜Ｘ^７はそれぞれ独立に、水素原子、ハロゲン原子、直鎖、分岐又は環状のアルキル基、直鎖、分岐又は環状のアルコキシ基、置換又は未置換のアラルキル基、置換又は未置換のアリール基、置換又は未置換のアラルキルオキシ基、置換又は未置換のアリールオキシ基、あるいは、置換または未置換のアルケニル基を表し、さらに、Ｘ^１とＸ^２、Ｘ^２とＸ^３、Ｘ^４とＸ^５、Ｘ^５とＸ^６、及びＸ^６とＸ^７から選ばれる隣接する基は互いに結合して、置換している炭素原子と共に、置換又は未置換の炭素環式脂肪族環、あるいは置換又は未置換の炭素環式芳香族環を形成していてもよい。）

(Wherein, X ^{1 to} X ⁷ are each independently a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkoxy group, a substituted or unsubstituted aralkyl group, a substituted or Represents an unsubstituted aryl group, a substituted or unsubstituted aralkyloxy group, a substituted or unsubstituted aryloxy group, or a substituted or unsubstituted alkenyl group; and X ¹ and X ² , X ² and X ³ , Adjacent groups selected from X ⁴ and X ⁵ , X ⁵ and X ⁶ , and X ⁶ and X ⁷ are bonded to each other, together with a substituted carbon atom, a substituted or unsubstituted carbocyclic aliphatic ring, Alternatively, a substituted or unsubstituted carbocyclic aromatic ring may be formed.)

（式中、Ｒ^４〜Ｒ^７は各々独立して水素原子、ハロゲン原子、又は下記式［１４］で示される基を表わす。）

(In the formula, R ^{4 to} R ⁷ each independently represents a hydrogen atom, a halogen atom, or a group represented by the following formula [14].)

（式中、Ｒ^８及びＲ^９は、各々独立して水素原子、アルキル基、アリール基、又は、Ｒ^８及びＲ^９が一緒になってシクロアルキル基若しくは複素環基を完成させる原子若しくは基を表す。）

(In the formula, R ⁸ and R ⁹ each independently represent a hydrogen atom, an alkyl group, an aryl group, or an atom or group that R ⁸ and R ⁹ together form a cycloalkyl group or a heterocyclic group. To express.)

（式中、Ｒ^１０は水素原子、ヒドロキシル基、アミノ基、置換基を有していてもよい低級アルキル基、置換基を有していてもよいアルキルアミノ基、置換基を有していてもよいアルコキシ基、置換基を有していてもよい芳香族炭化水素を、ｑは１から５までの整数を表し、（Ｒ^１０）ｑは同一或いは異なる前記Ｒ^１０がｑで表される数だけ結合していることを示し、また、Ｒ^１１〜Ｒ^１６は、同一或いは異なっていて、水素原子、ハロゲン原子、シアノ基、置換基を有していてもよい低級アルキル基、置換基を有していてもよいアルキルアミノ基、置換基を有していてもよいアルコキシ基、置換基を有していてもよい芳香族炭化水素を示す。）

(In the formula, R ¹⁰ may have a hydrogen atom, a hydroxyl group, an amino group, a lower alkyl group which may have a substituent, an alkylamino group which may have a substituent, or a substituent. A good alkoxy group, an aromatic hydrocarbon which may have a substituent, q represents an integer of 1 to 5, and (R ¹⁰ ) q is the same or different as many as R ¹⁰ is represented by q R ^{11 to} R ¹⁶ are the same or different and have a hydrogen atom, a halogen atom, a cyano group, a lower alkyl group which may have a substituent, or a substituent. An alkylamino group which may have a substituent, an alkoxy group which may have a substituent, and an aromatic hydrocarbon which may have a substituent.

（式中、Ｒ^１７〜Ｒ^２２は、それぞれ同一又は異なって、水素原子、ハロゲン原子、アルキル基、アルコキシ基、または置換基を有してもよいアリール基を示す。）

(In formula, R < ¹⁷ > -R < ²² > is the same or different, respectively, and shows the aryl group which may have a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a substituent.)

（式中Ｒ^２３〜Ｒ^２６は、それぞれ同一又は異なって、水素原子、ハロゲン原子、アルキル基、アルコキシ基、又は置換基を有してもよいアリール基を示す。）

(In formula, R < ²³ > -R < ²⁶ > is the same or different, respectively, and shows the aryl group which may have a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a substituent.)

［式中、Ｘ^８及びＹ^１は、それぞれ独立に炭素数１から６までの飽和若しくは不飽和の炭化水素基、アルコキシ基、アルケニルオキシ基、アルキニルオキシ基、ヒドロキシ基、置換若しくは無置換のアリール基、置換若しくは無置換のヘテロ環又はＸ^１とＹ^１が結合して飽和又は不飽和の環を形成した構造であり、Ｒ^２７〜Ｒ^３０は、それぞれ独立に水素、ハロゲン、置換もしくは無置換の炭素数１から６までのアルキル基、アルコキシ基、アリールオキシ基、パーフルオロアルキル基、パーフルオロアルコキシ基、アミノ基、アルキルカルボニル基、アリールカルボニル基、アルコキシカルボニル基、アリールオキシカルボニル基、アゾ基、アルキルカルボニルオキシ基、アリールカルボニルオキシ基、アルコキシカルボニルオキシ基、アリールオキシカルボニルオキシ基、スルフィニル基、スルフォニル基、スルファニル基、シリル基、カルバモイル基、アリール基、ヘテロ環基、アルケニル基、アルキニル基、ニトロ基、ホルミル基、ニトロソ基、ホルミルオキシ基、イソシアノ基、シアネート基、イソシアネート基、チオシアネート基、イソチオシアネート基もしくはシアノ基又は隣接した場合には置換若しくは無置換の環が縮合した構造である。（但し、Ｒ^２７及びＲ^３０がフェニル基の場合、Ｘ^８及びＹ^１は、アルキル基及びフェニル基ではなく、Ｒ^２７及びＲ^３０がチエニル基の場合、Ｘ^８及びＹ^１は、一価炭化水素基を、Ｒ^２８及びＲ^２９は、アルキル基、アリール基、アルケニル基又はＲ^２８とＲ^２９が結合して環を形成する脂肪族基を同時に満たさない構造であり、Ｒ^２７及びＲ^３０がシリル基の場合、Ｒ^２８、Ｒ^２９、Ｘ^８及びＹ^１は、それぞれ独立に、炭素数１から６の一価炭化水素基又は水素原子でなく、Ｒ^１及びＲ^２でベンゼン環が縮合した構造の場合、Ｘ^８及びＹ^１は、アルキル基及びフェニル基ではない）。］ The silicon-containing ring compound is preferably represented by the following formula [18].

[Wherein, X ⁸ and Y ¹ are each independently a saturated or unsaturated hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group, an alkenyloxy group, an alkynyloxy group, a hydroxy group, a substituted or unsubstituted aryl group. A group, a substituted or unsubstituted heterocycle, or a structure in which X ¹ and Y ¹ are combined to form a saturated or unsaturated ring, and R ^{27 to} R ³⁰ are each independently hydrogen, halogen, substituted or unsubstituted Alkyl group having 1 to 6 carbon atoms, alkoxy group, aryloxy group, perfluoroalkyl group, perfluoroalkoxy group, amino group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, azo group , Alkylcarbonyloxy group, arylcarbonyloxy group, alkoxycarbonyloxy group , Aryloxycarbonyloxy group, sulfinyl group, sulfonyl group, sulfanyl group, silyl group, carbamoyl group, aryl group, heterocyclic group, alkenyl group, alkynyl group, nitro group, formyl group, nitroso group, formyloxy group, isocyano group , A cyanate group, an isocyanate group, a thiocyanate group, an isothiocyanate group or a cyano group, or when adjacent, a substituted or unsubstituted ring is condensed. (However, when R ²⁷ and R ³⁰ are phenyl groups, X ⁸ and Y ¹ are not alkyl groups and phenyl groups, and when R ²⁷ and R ³⁰ are thienyl groups, X ⁸ and Y ¹ are monovalent carbonizations. A hydrogen group, R ²⁸ and R ²⁹ are structures that do not satisfy an alkyl group, an aryl group, an alkenyl group, or an aliphatic group in which R ²⁸ and R ²⁹ are combined to form a ring, and R ²⁷ and R ³⁰ are In the case of a silyl group, R ²⁸ , R ²⁹ , X ⁸ and Y ¹ are each independently a monovalent hydrocarbon group or hydrogen atom having 1 to 6 carbon atoms, but a benzene ring is condensed with R ¹ and R ² . In the case of structure, X ⁸ and Y ¹ are not alkyl groups and phenyl groups). ]

（式中、Ｒ^３１〜Ｒ^３８及びＺ^３は、それぞれ独立に、水素原子、飽和もしくは不飽和の炭化水素基、芳香族基、ヘテロ環基、置換アミノ基、置換ボリル基、アルコキシ基又はアリールオキシ基を示し、Ｘ^９、Ｙ^２及びＺ^２は、それぞれ独立に、飽和もしくは不飽和の炭化水素基、芳香族基、ヘテロ環基、置換アミノ基、アルコキシ基又はアリールオキシ基を示し、Ｚ^２とＺ^３の置換基は相互に結合して縮合環を形成してもよく、ｒは１〜３の整数を示し、ｒが２以上の場合、Ｚ^２は異なってもよい。但し、ｒが１、Ｘ^９、Ｙ^２及びＲ^３２がメチル基であって、Ｒ^３８が水素原子又は置換ボリル基の場合、及びｒが３でＺ^２がメチル基の場合を含まない。） The boron compound is preferably represented by the following formula [19].

Wherein R ^{31 to} R ³⁸ and Z ³ are each independently a hydrogen atom, a saturated or unsaturated hydrocarbon group, an aromatic group, a heterocyclic group, a substituted amino group, a substituted boryl group, an alkoxy group or an aryl X ⁹ , Y ² and Z ² each independently represents a saturated or unsaturated hydrocarbon group, aromatic group, heterocyclic group, substituted amino group, alkoxy group or aryloxy group; The substituents of ² and Z ³ may be bonded to each other to form a condensed ring, and r represents an integer of 1 to 3, and when r is 2 or more, Z ² may be different, provided that r 1, X ⁹ , Y ² and R ³² are methyl groups, and R ³⁸ is a hydrogen atom or a substituted boryl group, and r is 3 and Z ² is a methyl group.

（式中、Ｑ^１、Ｑ^２は、下記式［２１］の構造を有する配位子であり、８−ヒドロキシキノリン、２−メチル−８−ヒドロキシキノリン等のキノリン残基があるが、これらに限られるものではない。Ｌ^４はハロゲン原子、置換若しくは未置換のアルキル基、置換若しくは未置換のシクロアルキル基、置換若しくは未置換のアリール基、置換若しくは未置換の複素環基、又は−Ｏ−Ｇａ−Ｑ^３（Ｑ^４）（但し、Ｑ^３、Ｑ^４はＱ^１、Ｑ^２と同じ意味）で示される配位子を表す。） Other compounds that can be used as the electron injection layer include those represented by the following formula [20].

(In the formula, Q ¹ and Q ² are ligands having the structure of the following formula [21], and there are quinoline residues such as 8-hydroxyquinoline and 2-methyl-8-hydroxyquinoline. L ⁴ is a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, or —O—. Ga-Q ³ (Q ⁴ ) (where Q ³ and Q ⁴ represent the same meanings as Q ¹ and Q ² ).)

（式中、環Ａ^４及びＡ^５は、互いに結合した置換もしくは未置換のアリール環もしくは複素環構造である。）
環Ａ^４及びＡ^５の、置換基の具体的な例を挙げると、塩素、臭素、ヨウ素、フッ素のハロゲン原子、メチル基、エチル基、プロピル基、ブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ステアリル基、トリクロロメチル基等の置換もしくは未置換のアルキル基、フェニル基、ナフチル基、３−メチルフェニル基、３−メトキシフェニル基、３−フルオロフェニル基、３−トリクロロメチルフェニル基、３−トリフルオロメチルフェニル基、３−ニトロフェニル基等の置換もしくは未置換のアリール基、メトキシ基、ｎ−ブトキシ基、ｔｅｒｔ−ブトキシ基、トリクロロメトキシ基、トリフルオロエトキシ基、ペンタフルオロプロポキシ基、２，２，３，３−テトラフルオロプロポキシ基、１，１，１，３，３，３−ヘキサフルオロ−２−プロポキシ基、６−（パーフルオロエチル）ヘキシルオキシ基等の置換もしくは未置換のアルコキシ基、フェノキシ基、ｐ−ニトロフェノキシ基、ｐ−ｔｅｒｔ−ブチルフェノキシ基、３−フルオロフェノキシ基、ペンタフルオロフェニル基、３−トリフルオロメチルフェノキシ基等の置換もしくは未置換のアリールオキシ基、メチルチオ基、エチルチオ基、ｔｅｒｔ−ブチルチオ基、ヘキシルチオ基、オクチルチオ基、トリフルオロメチルチオ基等の置換もしくは未置換のアルキルチオ基、フェニルチオ基、ｐ−ニトロフェニルチオ基、ｐｔｅｒｔ−ブチルフェニルチオ基、３−フルオロフェニルチオ基、ペンタフルオロフェニルチオ基、３−トリフルオロメチルフェニルチオ基等の置換もしくは未置換のアリールチオ基、シアノ基、ニトロ基、アミノ基、メチルアミノ基、ジエチルアミノ基、エチルアミノ基、ジエチルアミノ基、ジプロピルアミノ基、ジブチルアミノ基、ジフェニルアミノ基等のモノ又はジ置換アミノ基、ビス（アセトキシメチル）アミノ基、ビス（アセトキシエチル）アミノ基、ビスアセトキシプロピル）アミノ基、ビス（アセトキシブチル）アミノ基等のアシルアミノ基、水酸基、シロキシ基、アシル基、メチルカルバモイル基、ジメチルカルバモイル基、エチルカルバモイル基、ジエチルカルバモイル基、プロイピルカルバモイル基、ブチルカルバモイル基、フェニルカルバモイル基等のカルバモイル基、カルボン酸基、スルフォン酸基、イミド基、シクロペンタン基、シクロヘキシル基等のシクロアルキル基、フェニル基、ナフチル基、ビフェニル基、アントラニル基、フェナントリル基、フルオレニル基、ピレニル基等のアリール基、ピリジニル基、ピラジニル基、ピリミジニル基、ピリダジニル基、トリアジニル基、インドリニル基、キノリニル基、アクリジニル基、ピロリジニル基、ジオキサニル基、ピペリジニル基、モルフォリジニル基、ピペラジニル基、トリアチニル基、カルバゾリル基、フラニル基、チオフェニル基、オキサゾリル基、オキサジアゾリル基、ベンゾオキサゾリル基、チアゾリル基、チアジアゾリル基、ベンゾチアゾリル基、トリアゾリル基、イミダゾリル基、ベンゾイミダゾリル基、プラニル基等の複素環基等がある。
また、以上の置換基同士が結合してさらなる６員アリール環もしくは複素環を形成しても良い。

(Wherein rings A ⁴ and A ⁵ are substituted or unsubstituted aryl rings or heterocyclic structures bonded to each other.)
Specific examples of the substituents of the rings A ⁴ and A ⁵ include chlorine, bromine, iodine, halogen atoms of fluorine, methyl group, ethyl group, propyl group, butyl group, sec-butyl group, tert-butyl. Group, pentyl group, hexyl group, heptyl group, octyl group, stearyl group, trichloromethyl group and other substituted or unsubstituted alkyl groups, phenyl group, naphthyl group, 3-methylphenyl group, 3-methoxyphenyl group, 3- Fluorophenyl group, 3-trichloromethylphenyl group, 3-trifluoromethylphenyl group, substituted or unsubstituted aryl group such as 3-nitrophenyl group, methoxy group, n-butoxy group, tert-butoxy group, trichloromethoxy group , Trifluoroethoxy group, pentafluoropropoxy group, 2,2,3,3-tetrafluoropropoxy group Group, 1,1,1,3,3,3-hexafluoro-2-propoxy group, substituted or unsubstituted alkoxy group such as 6- (perfluoroethyl) hexyloxy group, phenoxy group, p-nitrophenoxy group P-tert-butylphenoxy group, 3-fluorophenoxy group, pentafluorophenyl group, substituted or unsubstituted aryloxy group such as 3-trifluoromethylphenoxy group, methylthio group, ethylthio group, tert-butylthio group, hexylthio Group, octylthio group, substituted or unsubstituted alkylthio group such as trifluoromethylthio group, phenylthio group, p-nitrophenylthio group, tert-butylphenylthio group, 3-fluorophenylthio group, pentafluorophenylthio group, 3 -Arrangement of trifluoromethylphenylthio group, etc. Mono- or di-substituted amino such as substituted or unsubstituted arylthio group, cyano group, nitro group, amino group, methylamino group, diethylamino group, ethylamino group, diethylamino group, dipropylamino group, dibutylamino group, diphenylamino group Group, acylamino group such as bis (acetoxymethyl) amino group, bis (acetoxyethyl) amino group, bisacetoxypropyl) amino group, bis (acetoxybutyl) amino group, hydroxyl group, siloxy group, acyl group, methylcarbamoyl group, dimethyl group Carbamoyl group, ethylcarbamoyl group, diethylcarbamoyl group, propylcarbamoyl group, butylcarbamoyl group, carbamoyl group such as phenylcarbamoyl group, carboxylic acid group, sulfonic acid group, imide group, cyclopentane group, cyclohexyl group, etc. Ryl group, phenyl group, naphthyl group, biphenyl group, anthranyl group, phenanthryl group, fluorenyl group, aryl group such as pyrenyl group, pyridinyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, triazinyl group, indolinyl group, quinolinyl group, acridinyl Group, pyrrolidinyl group, dioxanyl group, piperidinyl group, morpholidinyl group, piperazinyl group, triatinyl group, carbazolyl group, furanyl group, thiophenyl group, oxazolyl group, oxadiazolyl group, benzoxazolyl group, thiazolyl group, thiadiazolyl group, benzothiazolyl Groups, triazolyl groups, imidazolyl groups, benzoimidazolyl groups, and heterocyclic groups such as pranyl groups.
Moreover, the above substituents may combine to form a further 6-membered aryl ring or heterocyclic ring.

In the present invention, an electron injection layer composed of an insulator or a semiconductor may be further provided between the cathode and the organic layer. As a result, current leakage can be effectively prevented and the electron injection property can be improved. As such an insulator, it is preferable to use at least one metal compound selected from the group consisting of alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides and alkaline earth metal halides. If the electron injection layer is composed of these alkali metal chalcogenides or the like, it is preferable in that the electron injection property can be further improved. Specifically, preferable alkali metal chalcogenides include, for example, Li ₂ O, LiO, Na ₂ S, Na ₂ Se, and NaO, and preferable alkaline earth metal chalcogenides include, for example, CaO, BaO, SrO, and BeO. , BaS, and CaSe. Further, preferable alkali metal halides include, for example, LiF, NaF, KF, LiCl, KCl, and NaCl. Examples of preferable alkaline earth metal halides include fluorides such as CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ and BeF ₂ , and halides other than fluorides.

Moreover, in this invention, it is preferable to contain a reducing dopant in the area | region which conveys an electron, or the interface area | region of a cathode and an organic layer.
Here, the reducing dopant is defined as a substance capable of reducing the electron transporting compound, and various substances can be used as long as they have a certain reducing ability. For example, alkali metal, alkaline earth metal, rare earth metal, alkali metal oxide, alkali metal halide, alkaline earth metal oxide, alkaline earth metal halide, rare earth metal oxide or rare earth metal At least one substance selected from the group consisting of halides, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals can be preferably used.

  Preferred reducing dopants have a work function of 2.9 eV or less, such as Na (work function: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16 eV), and Cs. (Work function: 1.95 eV) at least one alkali metal selected from the group consisting of Ca (work function: 2.9 eV), Sr (work function: 2.0-2.5 eV), and Ba (work And at least one alkaline earth metal selected from the group consisting of (function: 2.52 eV).

Among these, a more preferable reducing dopant is at least one alkali metal selected from the group consisting of K, Rb, and Cs, more preferably Rb or Cs, and most preferably Cs. . These alkali metals have a particularly high reducing ability, and the addition of a relatively small amount to the electron injection region can improve the light emission luminance and extend the life of the organic EL element.
Further, as a reducing dopant having a work function of 2.9 eV or less, a combination of two or more alkali metals is also preferable. Particularly, a combination containing Cs, such as Cs and Na, Cs and K, Cs and Rb, or Cs. And a combination of Na and K. By including Cs in combination, the reducing ability can be efficiently exhibited, and by adding to the electron injection region, the emission luminance and the life of the organic EL element can be improved.

(9) Cathode As the cathode, those having a work function (4 eV or less) metal, an alloy, an electrically conductive compound and a mixture thereof as an electrode material are used. Specific examples of such an electrode material include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / silver alloy, aluminum / aluminum oxide, aluminum / lithium alloy, indium, rare earth metal, and the like.
The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.

Here, when light emitted from the light emitting layer is taken out from the cathode, it is preferable that the transmittance with respect to the light emitted from the cathode is larger than 10%.
The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 nm to 1 μm, preferably 50 to 200 nm.

(10) Insulating layer Since organic EL applies an electric field to an ultra-thin film, pixel defects are likely to occur due to leakage or short circuit. In order to prevent this, it is preferable to insert an insulating thin film layer between the pair of electrodes.
Examples of the material used for the insulating layer include aluminum oxide, lithium fluoride, lithium oxide, cesium fluoride, cesium oxide, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, aluminum nitride, titanium oxide, and silicon oxide. Germanium oxide, silicon nitride, boron nitride, molybdenum oxide, ruthenium oxide, vanadium oxide, and the like.
A mixture or laminate of these may be used.

(11) Preparation Example of Organic EL Element By forming an anode, a light emitting layer, an electron injection suppressing layer, an electron injection layer, and a hole injection layer as required by the materials and methods exemplified above, and further forming a cathode. An organic EL element can be produced. Moreover, an organic EL element can also be produced from the cathode to the anode in the reverse order.
Hereinafter, an example of a method for producing the organic EL element (translucent substrate / anode / hole injection layer / light emitting layer / electron injection suppression layer / electron injection layer / cathode) having the configuration shown in FIG. 1 will be described.
First, an anode 12 is produced by forming a thin film made of an anode material on a suitable light-transmitting substrate 11 by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm. .

Next, a hole injection layer 13 is provided on the anode 12. The hole injection layer 13 can be formed by a method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, etc., but it is easy to obtain a homogeneous film and pinholes are not easily generated. It is preferable to form by vacuum evaporation.
When the hole injection layer 13 is formed by a vacuum deposition method, the deposition conditions vary depending on the compound used (material of the hole injection layer), the crystal structure and recombination structure of the target hole injection layer, etc. The deposition source temperature is 50 to 450 ° C., the degree of vacuum is 10 ⁻⁷ to 10 ⁻³ torr, the deposition rate is 0.01 to 50 nm / second, the substrate temperature is −50 to 300 ° C., and the film thickness is 5 nm to 5 μm. preferable.

  Next, the light emitting layer 14 is provided on the hole injection layer 13. The light-emitting layer 14 can also be formed by thinning the organic light-emitting material using a desired organic light-emitting material by a method such as vacuum deposition, sputtering, spin coating, or casting, but a homogeneous film can be obtained. It is preferable to form the film by a vacuum deposition method from the viewpoint that it is easy and pinholes are hardly generated. When the light emitting layer 14 is formed by the vacuum vapor deposition method, the vapor deposition condition varies depending on the compound to be used, but can generally be selected from the same condition range as that of the hole injection layer.

Next, the electron injection suppression layer 15 is provided on the light emitting layer. Although it can be thinned by a method such as vacuum deposition, sputtering, spin coating, or casting using a desired organic material, it is necessary to obtain a uniform film as with the hole injection layer 13 and the light emitting layer 14. It is preferable to form by a vacuum evaporation method. The vapor deposition conditions can be selected from the same condition ranges as those for the hole injection layer 13 and the light emitting layer 14.
Next, the electron injection layer 16 is provided on the electron injection suppression layer 15. Also in this case, it can be selected from the same condition range as described above.

Finally, the cathode 17 can be laminated to obtain an organic EL element.
The cathode 17 is made of metal, and vapor deposition or sputtering can be used. However, vacuum deposition is preferred to protect the underlying organic layer from damage during film formation.
The organic EL element is preferably manufactured from the anode to the cathode consistently by a single vacuum.

  In addition, the formation method of each layer of the organic EL element of this invention is not limited to said method, The formation method by a conventionally well-known vacuum evaporation method, a spin coating method, etc. can be used. In addition, the organic thin film layer is known by a coating method such as a vacuum deposition method, a molecular beam deposition method (MBE method), a solution dipping method in a solvent, a spin coating method, a casting method, a bar coating method, or a roll coating method. Can be formed by a method.

  The film thickness of each organic layer of the organic EL element is not particularly limited, but generally, if the film thickness is too thin, defects such as pinholes are likely to occur, and conversely, if it is too thick, a high applied voltage is required and the efficiency deteriorates. Usually, the range of several nm to 1 μm is preferable.

(12) Others When a direct current voltage is applied to the organic EL element, light emission can be observed by applying a voltage of 2 to 40 V with a positive polarity of the anode and a negative polarity of the cathode. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Furthermore, when an alternating voltage is applied, uniform light emission is observed only when the anode has a positive polarity and the cathode has a negative polarity. The waveform of the alternating current to be applied may be arbitrary.

Examples of the present invention will be described in detail below, but the present invention is not limited to these examples.
In addition, the property of the compound used in each Example and the produced element were evaluated by the following method.
(1) Affinity level: calculated from the difference between the ionization potential and the energy gap.
The ionization potential was measured using an atmospheric photoelectron spectrometer (manufactured by Riken Keiki Co., Ltd .: AC-1). Specifically, the measurement was performed by irradiating the material with light and measuring the amount of electrons generated by charge separation at that time.
The energy gap was measured from the absorption edge of the absorption spectrum in benzene. Specifically, the absorption spectrum was measured using a visible / ultraviolet spectrophotometer (Hitachi, U-3410) and calculated from the wavelength at which the spectrum started rising.
(2) Electron mobility / hole mobility: Measured using a TIME OF FLIGHT measuring apparatus (Optel, TOF-301).
(3) Luminance: Measured with a spectral radiance meter (CS-1000, manufactured by Minolta).
(4) x, y of chromaticity coordinates CIE1931: Measured with a spectral radiance meter described in (3).
(5) Luminous efficiency (L / J): L / J is the ratio of luminance to current density. The current and voltage were measured using a SOURCE MEASURE UNIT 236 (manufactured by KEITHLEY), and at the same time, the luminance was measured with a spectral radiance meter, the current density was calculated from the current value and the light emitting area, and L / J was calculated.
(6) Power conversion efficiency η: calculated by the following formula.
η = π × (L / J) / V
(In the formula, π is the pi, L / J is the luminous efficiency, and V is the voltage.)

The compounds used in the examples are shown below. In addition, among these compounds, Table 1 shows the electron mobility and affinity (Af) level of the compounds used in the electron injection layer, the electron injection suppression layer, or the light emitting layer.

Example 1
A 25 mm × 75 mm × 1.1 mm thick ITO (film thickness 130 nm) glass substrate with a transparent electrode (manufactured by Geomatic) was subjected to ultrasonic cleaning in isopropyl alcohol for 5 minutes, and then with distilled water having an electric resistance of 20 MΩm. Ultrasonic cleaning was performed for 5 minutes. Furthermore, ultrasonic cleaning was performed in isopropyl alcohol for 5 minutes, and then the ITO substrate was taken out and dried.
Immediately thereafter, UV ozone cleaning was performed for 30 minutes using a UV ozone apparatus manufactured by Samco International Laboratory.

The glass substrate with a transparent electrode line after washing was mounted on a substrate holder of a vacuum deposition apparatus, and the inside of the apparatus was evacuated to 1 × 10 ⁻⁵ Pa.
Subsequently, on the surface on which the transparent electrode line is formed, the transparent electrode is covered, the deposition rate is 0.1 nm / sec, and N, N′-bis (N, N A '-diphenyl-4-aminophenyl) -N, N-diphenyl-4,4'-diamino-1,1'-biphenyl film (hereinafter abbreviated as “TPD232 film”) was formed. This TPD232 film functions as a hole injection layer.

Subsequently, a 20 nm thick N, N, N ′, N′-tetra (4-biphenyl) -diaminobiphenylene layer or lower “TBDB layer” is formed on the TPD232 film at a deposition rate of 0.1 nm / sec. Was deposited. This film functions as a hole transport layer.
Further, a host H1 having a thickness of 40 nm was deposited at a deposition rate of 0.2 nm / sec to form a film.
At the same time, dopant D1 was deposited as a luminescent molecule at a deposition rate of 0.01 nm / sec. This film functions as a light emitting layer.

An Alq film having a thickness of 7 nm was formed as an electron injection suppressing layer on the light emitting layer at a deposition rate of 0.1 nm / sec.
Further, as an electron injection layer, ET1 was deposited at a deposition rate of 0.1 nm / sec to a thickness of 13 nm.
Lithium fluoride LiF was deposited at a deposition rate of 0.01 nm / sec and a film thickness of 1 nm, and metal Al was deposited thereon at a deposition rate of 0.8 nm / sec to form a metal cathode to emit organic EL. An element was formed.
The initial performance of this organic EL element was measured. As a result, at a current density of 1 mA / cm ² , the driving voltage was 4.0 V, 13 cd / A, and CIE _{x, y} = (0.16, 0.25). The results are shown in Table 2.

Reference example 1
A material similar to that of Example 1 was prepared, except that BCP was used as the material for the electron injection layer, and Cs was co-evaporated with an alkaline dispenser manufactured by SAES Getter and no lithium fluoride LiF layer was formed. Table 2 shows the evaluation results of the elements.

Comparative Example 1
In Example 1, it produced similarly except not forming the Alq film | membrane which is an electron injection suppression layer, but having made the film thickness of ET1 which is an electron injection layer into 20 nm. Table 2 shows the evaluation results of the elements.
Compared with the element of Example 1, this organic EL element does not have an electron injection suppression layer, so the drive voltage is reduced, but the number of electrons is excessive, so the L / J efficiency is remarkably low. For this reason, it has confirmed that Example 1 was more excellent in the power conversion efficiency which shows the comprehensive efficiency of an element.
Further, the luminance half life was several tenths of that of the device of Example 1.

Comparative Example 2
In Reference Example 1, a film was produced in the same manner except that the film thickness of BCP as the electron injection layer was changed to 20 nm without forming the Alq film as the electron injection suppression layer. Table 2 shows the evaluation results of the elements.
Compared with the element of Reference Example 1, this organic EL element does not have an electron injection suppression layer, so the drive voltage is reduced, but the L / J efficiency is remarkably low because of excessive electrons. For this reason, it has confirmed that the reference example 1 was superior in the power conversion efficiency which shows the comprehensive efficiency of an element.
Further, the luminance half-life was several tenths of that of the device of Reference Example 1.

Example 2
The organic EL element was fabricated in the same manner as in Example 1 except that ET2 was used instead of Alq as the electron injection suppressing layer, the film thickness was 10 nm, and the film thickness of ET1 as the electron injection layer was 10 nm. Produced.

Reference example 2
In Example 1, instead of the hole injection layer made of TPD232, a hole injection suppression layer made of TPD787 was formed, and a layer made of TBDB was similarly formed thereon to form a hole injection layer. Further, an organic EL element was produced in the same manner as in Example 1 except that the electron injection layer made of ET1 was not formed, the thickness of the Alq layer was 20 nm, and this was used as the electron injection layer. Table 2 shows the evaluation results of the elements.
The hole mobility of TPD232 is 10 ⁻⁴ cm ² / V · s, the hole mobility of TPD787 is 10 ⁻⁵ cm ² / V · s, and the hole mobility of TBDB is 10 ⁻³ cm. ² / V · s.

Comparative Example 3
In the organic EL element of Example 1, an organic EL element was produced in the same manner as in Example 1 except that the electron injection layer made of ET1 was not formed, the thickness of the Alq layer was 20 nm, and this was used as the electron injection layer. did. Table 2 shows the evaluation results of the elements.

  The organic EL element of the present invention can be used for display screens of various display devices such as consumer TVs, large display displays, and mobile phone display screens.

DESCRIPTION OF SYMBOLS 1 Organic EL element 11 Substrate 12 Anode 13 Hole injection layer 14 Light emitting layer 15 Electron injection suppression layer 16 Electron injection layer 17 Cathode

Claims (7)

An organic electroluminescent element having a light emitting layer between a pair of electrodes, an anode and a cathode,
An electron injection layer and an electron injection suppression layer are provided between the cathode and the light emitting layer, and the amount of electrons supplied to the light emitting layer is adjusted,
The electron mobility of the electron injection suppression layer is smaller than the electron mobility of the electron injection layer,
The electron mobility of the electron injection layer is greater than that of the tris (8-quinolinolato) aluminum complex,
An organic electroluminescence device, wherein the electron injection layer is made of a compound represented by the following formula.
^{HAr-L 3} -Ar 7 -Ar ⁸
(Wherein, HAr is substituted a nitrogen-containing heterocyclic ring of good has 3 to 40 carbon atoms, L ³ represents a single bond, a good number of carbon atoms from 6 may have a substituent An arylene group having 60, a heteroarylene group having 3 to 60 carbon atoms which may have a substituent, or a fluorenylene group optionally having a substituent, and Ar ⁷ may have a substituent. It is a good C6-C60 bivalent aromatic hydrocarbon group, Ar < ⁸ > may have a C6-C60 aryl group which may have a substituent, or a substituent. (This is a heteroaryl group having 3 to 60 carbon atoms.) L ³ Is an arylene group having 6 to 60 carbon atoms which may have a single bond or a substituent, and Ar ⁷ Is an anthracene ring optionally having a substituent, Ar ⁸ The organic electroluminescent element according to claim 1, wherein is an aryl group having 6 to 60 carbon atoms which may have a substituent. L ³ Is an arylene group having 6 to 60 carbon atoms which may have a substituent. The organic electroluminescence device according to claim 1 or 2. The affinity level (Af1) of the light emitting layer, the affinity level (Af2) of the electron injection suppressing layer, and the affinity level (Af3) of the electron injection layer satisfy the relationship of Af1 <Af2, Af3 ≦ Af2. The organic electroluminescent element according to claim 1 , wherein The organic electroluminescence device according to any one of claims 1 to 4 , wherein the electron injection suppression layer is made of a nitrogen-containing ring compound. The organic light-emitting device according to claim 1 , wherein the light-emitting layer emits blue light. The display apparatus which has a display screen comprised including the organic electroluminescent element as described in any one of Claims 1-6 .

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