JP2000104056A - Material for organic light-emitting element and organic light-emitting element made therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material having a high color purity, a high luminance, and a high efficiency of light emission by selecting a specified organosulfur compound. SOLUTION: A compound of formula I is selected. In the formula, R1 and R2 are each an aliphatic hydrocarbon group, an aryl, or a heterocyclic group, desirably, an aryl or an aromatic heterocyclic group; and m is 2 or 3, desirably 2. The compound of formula I may be any one of a low-molecular-weight compound, a high-molecular- weight compound composed of a polymer chain and residues bonded thereto and desirably having a weight-average molecular weight of 1,000-5,000,000, and a high- molecular-weight compound having a compound of formula I in the main chain and desirably having a weight-average molecular weight of 1,000-5,000,000. An example of a compound of formula I is a compound of formula II. An element excellent in stability upon repeated use and capable of being made by a coating method can be obtained by forming an organic light-emitting element prepared by forming a luminous layer or a plurality of organic compound thin film each of which contains a luminous layers between a pair of electrodes and in which at least one the layers is one containing a compound of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for a light emitting device (organic light emitting device) and a light emitting device which can emit light by converting electric energy into light. The present invention relates to a light emitting element that can be suitably used in fields such as a light source, a reading light source, a sign, a signboard, and interior.

[0002]

2. Description of the Related Art At present, research and development on various display elements are active. Among them, organic light-emitting elements have attracted attention as promising display elements because they can obtain high-luminance light emission at a low voltage. For example, a light emitting device that forms an organic thin film by vapor deposition of an organic compound is known (Applied
Physics Letters, 51, 913, 1987
Year). The organic light emitting device described in this document is Tris (8
-Hydroxyquinolinato) aluminum complex (Alq)
Is used as an electron transporting material, and is laminated with a hole transporting material (amine compound), whereby the light emitting characteristics are greatly improved as compared with the conventional single-layer type device.

[0003] As a means for further improving the luminous efficiency of the stacked type light emitting device, a method of doping a fluorescent dye is known. For example, the organic light-emitting device doped with a coumarin dye described in Journal of Applied Physics, Vol. 65, p. 3610, 1989 has greatly improved luminous efficiency as compared with a non-doped device. In this case, it is possible to extract light of a desired wavelength by changing the type of the fluorescent compound to be used. However, when Alq is used as the electron transporting material, when the driving voltage is increased to obtain high luminance, the doping is prevented. In addition to the emission of the fluorescent compound
Since green emission of q is observed, reduction of color purity is a problem in emitting blue or red light, and development of a host material that does not reduce color purity is desired.

Although the organic EL devices developed so far have been improved in light emission intensity and durability due to improvements in device structure and materials, etc., they are still insufficient when considering various applications. Does not have good performance. For example, A
Conventional metal complexes such as 1q are chemically unstable during electroluminescence, have poor adhesion to the cathode, and do not solve the problem of device deterioration. Further, Alq is a complex using oxine as a ligand, and its material safety is also concerned. Therefore, development of an electron transporting material for an organic light-emitting device having no safety problem has been demanded. In addition, even azole-based electron transporting materials represented by oxadiazoles and triazoles are liable to cause element degradation due to crystallization due to heat generation during driving, separation of the interface between the organic layer and the cathode, and the like. It is desired to develop a material for preventing crystallization and improving the adhesion at the layer interface.

On the other hand, organic light-emitting devices that achieve high-luminance light emission are devices in which organic substances are stacked by vacuum deposition. However, from the viewpoints of simplification of the manufacturing process, workability, and large area, etc. It is desirable to produce the element by a coating method.
However, a device manufactured by a conventional coating method is inferior to a device manufactured by a vapor deposition method in terms of luminous luminance and luminous efficiency, and high luminance and highly efficient luminescence have been major issues.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a material for an organic light-emitting device and an organic light-emitting device having good light-emitting characteristics and excellent stability when used repeatedly.

[0007]

This object has been achieved by the following means. (1) An organic light-emitting device material, which is a compound represented by the following general formula (I).

[0008]

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(Wherein, R ¹ and R ² each represent an aliphatic hydrocarbon group, an aryl group, or a heterocyclic group, and m represents 2 or 3.) (2) a light emitting layer or a light emitting layer between a pair of electrodes; An organic light-emitting device having a plurality of organic compound thin films including a light-emitting layer, wherein at least one layer is a layer containing the organic light-emitting device material of (1). (3) In an organic light emitting device having a light emitting layer or a plurality of organic compound thin films including the light emitting layer formed between a pair of electrodes, at least one layer is a layer in which the organic light emitting device material of (1) is dispersed in a polymer. Organic light-emitting device characterized by the following. (4) In an organic light emitting device having a light emitting layer or a plurality of organic compound thin films including the light emitting layer formed between a pair of electrodes, at least one layer is a layer containing the organic light emitting device material of (1), and at least one electrode Contains silver and / or gold.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION First, the compound represented by formula (I) of the present invention will be described in detail. The aliphatic hydrocarbon group represented by R ¹ or R ² may be linear, branched or cyclic, and is preferably an alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms). And particularly preferably have 1 to 12 carbon atoms, for example, methyl, ethyl, i
so-propyl, tert-butyl, n-octyl, n
-Decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl and the like. ), An alkenyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 20 carbon atoms, particularly preferably having 2 to 12 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, and 3-pentenyl. ), An alkynyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 20 carbon atoms, particularly preferably having 2 to 12 carbon atoms, and examples thereof include propargyl and 3-pentynyl). Is an alkyl group or an alkenyl group, more preferably an alkyl group.

The aryl group represented by R ¹ and R ² is a monocyclic or condensed aryl group, preferably having 6 to 3 carbon atoms.
0, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyl, 4-methylphenyl, 4-methoxyphenyl, 3-trifluoromethylphenyl, pentafluorophenyl, 1-naphthyl, 2
-Naphthyl and the like. The heterocyclic group represented by R ¹ or R ² is a monocyclic or condensed heterocyclic group (preferably a heterocyclic group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 2 to 10 carbon atoms). Ring group), and is preferably an aromatic heterocyclic group containing at least one of a nitrogen atom, an oxygen atom, a sulfur atom and a selenium atom. Specific examples of the heterocyclic group represented by R ¹ and R ² include, for example, pyrrolidine,
Piperidine, pyrrole, furan, thiophene, imidazoline, imidazole, benzimidazole, naphthimidazole, thiazolidine, thiazole, benzothiazole, naphthothiazole, isothiazole, oxazoline, oxazole, benzoxazole, naphthoxazole, isoxazole, selenazole, benzoselenazole, Naphthoselenazole, pyridine, quinoline,
Isoquinoline, indole, indolenine, pyrazole, pyrazine, pyrimidine, pyridazine, triazine,
Indazole, purine, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, phenanthridine, pteridine, phenanthroline, tetrazaindene, oxadiazole, thiadiazole, triazole, tetrazole and the like, preferably pyrrole, furan, thiophene, Imidazole, benzimidazole, naphthoimidazole, thiazole, benzthiazole, naphthothiazole, isothiazole, oxazole, benzoxazole, naphthoxazole, isoxazole, selenazole, benzselenazole, naphthoselenazole, pyridine, quinoline, isoquinoline, indole, indolenine , Pyrazole, pyrazine, pyrimidine, pyridazine, triazine, indazole, purine, Razine, naphthyridine, quinoxaline, quinazoline, tetrazaindene, oxadiazole, thiadiazole, triazole, tetrazole, more preferably thiophene, imidazole, benzimidazole, naphthimidazole, thiazole, benzthiazole, naphthothiazole, isothiazole, oxazole, Benzoxazole, naphthoxazole, isoxazole, selenazole, benzselenazole, naphthoselenazole, pyrazine, pyrimidine, pyridazine, triazine, oxadiazole, thiadiazole, triazole, tetrazole, and more preferably oxadiazole, thiadiazole, triazole, Tetrazole, particularly preferably oxadiazole, thiadiazole and triazole. .

An aliphatic hydrocarbon group represented by R ¹ or R ² ;
The aryl group and the heterocyclic group may have a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 2 carbon atoms).
0, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, Cyclopentyl, cyclohexyl and the like can be mentioned. ), An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, particularly preferably having 2 to 8 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, and 3-pentenyl. ), Alkynyl group (preferably having 2 to 2 carbon atoms)
20, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, such as propargyl and 3-pentynyl. ), An aryl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 20 carbon atoms, particularly preferably having 6 to 12 carbon atoms, for example, phenyl, p-
Methylphenyl, naphthyl and the like can be mentioned. ), An amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, and examples thereof include amino, methylamino, dimethylamino, diethylamino, and dibenzylamino. ), An alkoxy group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 12 carbon atoms, particularly preferably having 1 to 8 carbon atoms, and examples thereof include methoxy, ethoxy, and butoxy), and aryloxy. Group (preferably having 6 to 2 carbon atoms)
It has 0, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples include phenyloxy and 2-naphthyloxy. ), An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, acetyl,
Benzoyl, formyl, pivaloyl and the like can be mentioned. ), An alkoxycarbonyl group (preferably having 2 carbon atoms)
-20, more preferably 2-16 carbon atoms, particularly preferably 2-12 carbon atoms, for example, methoxycarbonyl,
Ethoxycarbonyl and the like. ), An aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, and particularly preferably having 7 to 1 carbon atoms.
0, for example, phenyloxycarbonyl and the like. ), An acyloxy group (preferably having 2 to 2 carbon atoms)
It has 0, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 10 carbon atoms, and examples thereof include acetoxy and benzoyloxy. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably having 2 to 10 carbon atoms, for example, acetylamino, benzoylamino and the like), and an alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms,
More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino. ), An aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably having 7 carbon atoms)
To 16, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino. ), A sulfonylamino group (preferably having 1 to 2 carbon atoms)
0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, methanesulfonylamino,
Benzenesulfonylamino and the like. ), A sulfamoyl group (preferably having 0 to 20, more preferably 0 to 16, and particularly preferably 0 to 12 carbon atoms, for example, sulfamoyl, methylsulfamoyl,
Dimethylsulfamoyl, phenylsulfamoyl and the like can be mentioned. ), A sulfamoylamino group (preferably having 0 to 20, more preferably 1 to 16, and particularly preferably 1 to 12 carbon atoms, for example, sulfamoylamino, 3-methylsulfamoylamino, etc. Carbamoyl group (preferably having 1 to carbon atoms).
20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl and the like. ), An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms, such as methylthio and ethylthio, etc.), and an arylthio group (preferably carbon Number 6 to 20, more preferably carbon number 6
To 16, particularly preferably 6 to 12 carbon atoms, such as phenylthio. ), A sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 1 carbon atoms)
6, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl. ), A sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 1 carbon atoms)
6, particularly preferably 1 to 12 carbon atoms, for example, methanesulfinyl, benzenesulfinyl and the like. ), Ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 1 carbon atoms)
12, for example, ureide, methylureide, phenylureide and the like. ), A phosphoric amide group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 1 carbon atoms)
6, particularly preferably 1 to 12 carbon atoms, for example, diethylphosphoramide, phenylphosphoramide and the like. ), Hydroxy, mercapto, halogen (eg, fluorine, chlorine, bromine, iodine), cyano, sulfo, carboxyl, nitro, hydroxamic acid, sulfino, hydrazino,
Imino group, heterocyclic group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, Quinolyl, furyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.). These substituents may be further substituted. When there are two or more substituents, they may be the same or different. If possible, they may be linked to form a ring.

The substituent is preferably an alkyl group, an alkenyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, a cyano group, a halogen atom, or a heterocyclic group, and more preferably an alkyl group, an alkenyl group, an aralkyl group. Group, an aryl group, a halogen atom and an aromatic heterocyclic group, more preferably an alkyl group, an alkenyl group, an aryl group and an aromatic azole group.

R ¹ and R ² are preferably an aryl group,
An aromatic heterocyclic group, more preferably an aryl group,
It is an aromatic azole group, more preferably an aromatic azole group, particularly preferably oxadiazole, thiadiazole and triazole, and most preferably oxadiazole. m represents 2 or 3, and is preferably 2. Among the compounds represented by the general formula (I), a compound represented by the general formula (Ia) is more preferable.

[0015]

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In the formula, R ^a1 and R ^a2 each represent an aromatic heterocyclic group. The aromatic heterocyclic group has the same meaning as the aromatic heterocyclic group represented by R ¹ and R ² in formula (I), and the preferred range is also the same.

The compound represented by formula (I) of the present invention may be a low molecular weight compound or a high molecular weight compound having a residue connected to the polymer main chain (preferably a weight average molecular weight of 1,000 to 5,000,000, Particularly preferably 5000
~ 2,000,000, more preferably 10,000 ~ 10
00000) or a high molecular weight compound having the compound of the present invention in its main chain (preferably a weight average molecular weight of 1,000 to 5).
000000, particularly preferably 5000-200000
0, more preferably 10,000 to 1,000,000). In the case of a high molecular weight compound, it may be a homopolymer or a copolymer with another monomer.

The following are specific examples of the compound of the present invention, but the present invention is not limited thereto.

[0019]

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[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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The compound represented by the general formula (I) of the present invention can be prepared, for example, by using the following method:
4-III, Chapter 8, 8.4 or ORANIC FUNCTIONAL GR
OUP PREPARATIONS (Sandler, Karo, ACADEMIC PRESS Ne
w York and London) It can be synthesized by various methods as described in I-Chapt.

The light-emitting device of the present invention is a device in which a light-emitting layer or a plurality of organic compound thin films including the light-emitting layer are formed between a pair of anode and cathode electrodes. , An electron injection layer, an electron transport layer, a protective layer, and the like, and each of these layers may have another function. Various materials can be used for forming each layer.

The anode supplies holes to the hole injecting layer, the hole transporting layer, the light emitting layer, and the like. A metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof is used. It is possible to use a material having a work function of 4 eV or more. Specific examples include conductive metal oxides such as tin oxide, zinc oxide, indium oxide, and indium tin oxide (ITO), or metals such as gold, silver, chromium, and nickel, and furthermore, these metals and conductive metal oxides. Mixtures or laminates, inorganic conductive substances such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO, and the like. Oxides,
In particular, ITO is preferable in terms of productivity, high conductivity, transparency, and the like. The thickness of the anode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, and still more preferably 100 nm to 500 nm.

As the anode, a layer formed on a soda lime glass, an alkali-free glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass in order to reduce ions eluted from the glass. Further, when soda lime glass is used, it is preferable to use a glass coated with a barrier coat such as silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength. When glass is used, the thickness is usually 0.2 mm or more, preferably 0.7 mm or more. Various methods are used for producing the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating evaporation method, a chemical reaction method (such as a sol-gel method), and a coating of a dispersion of indium tin oxide are used. The film is formed by the method described above. The anode can be cleaned or otherwise treated to lower the device's drive voltage,
It is also possible to increase the luminous efficiency. For example, in the case of ITO, UV-ozone treatment or the like is effective.

The cathode supplies electrons to the electron injection layer, the electron transport layer, the light-emitting layer, and the like. The negative electrode, such as the electron injection layer, the electron transport layer, and the light-emitting layer, has good adhesion and ionization potential. It is selected in consideration of stability and the like. As the material of the cathode, a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used, and specific examples thereof include an alkali metal (eg, Li, Na, K, etc.) or a fluoride thereof, and an alkaline earth metal. Metals such as Mg, Ca
Etc.) or its fluorides, gold, silver, lead, aluminum,
Sodium-potassium alloy or a mixed metal thereof, lithium-aluminum alloy or a mixed metal thereof, magnesium-silver alloy or a mixed metal thereof, indium, rare earth metals such as ytterbium, and the like, preferably having a work function of 4 eV or less. The material is more preferably aluminum, a lithium-aluminum alloy or a mixed metal thereof, a magnesium-silver alloy, a magnesium-gold alloy or a mixed metal thereof. Further, from the viewpoint of preventing separation of the interface between the organic layer interface and the cathode, a magnesium-silver alloy and a magnesium-gold alloy are more preferable.
Magnesium-silver alloys are particularly preferred. This effect of preventing interfacial peeling is remarkably exhibited when the compound of the present invention is contained in the organic layer, particularly in the layer closest to the cathode, and a magnesium-silver alloy or a magnesium-gold alloy is used for the cathode. In addition, by applying an overcurrent before use, the present compound is changed to a mercapto compound, and the effect of preventing interfacial peeling is further improved due to the effect presumed to form a mercapto-metal bond at the cathode interface. The thickness of the cathode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, and still more preferably 100 nm to 1 μm. A method such as an electron beam method, a sputtering method, a resistance heating evaporation method, or a coating method is used for manufacturing the cathode, and a metal can be evaporated alone or two or more components can be simultaneously evaporated. Further, an alloy electrode can be formed by depositing a plurality of metals at the same time, or an alloy prepared in advance may be deposited. The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

The material of the light emitting layer is capable of injecting holes from an anode or a hole injection layer or a hole transport layer when applying an electric field, and also injecting electrons from a cathode or an electron injection layer or an electron transport layer. Any material can be used as long as it can form a layer having a function, a function of transferring injected charges, and a function of providing a field of recombination of holes and electrons to emit light. Preferably, the light-emitting layer contains the compound of the present invention, but other light-emitting materials of the compound of the present invention can also be used. For example, benzoxazole derivatives,
Benzimidazole derivatives, benzothiazole derivatives,
Styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, perylene derivatives, perinone derivatives, oxadiazole derivatives, aldazine derivatives, pyrazine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, Quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, cyclopentadiene derivatives, styrylamine derivatives, aromatic dimethylidin compounds, various metal complexes represented by metal complexes of 8-quinolinol derivatives and rare earth complexes, polythiophene, polyphenylene, polyphenylene And polymer compounds such as vinylene. Although the thickness of the light emitting layer is not particularly limited, it is usually 1n.
m to 5 μm, more preferably 5 to 5 μm.
nm to 1 μm, more preferably 10 nm to 500
nm. The method for forming the light-emitting layer is not particularly limited, but a method such as resistance heating evaporation, electron beam, sputtering, molecular lamination, coating (spin coating, casting, dip coating, etc.), and LB method And preferably a resistance heating evaporation and coating method.

The material of the hole injection layer and the hole transport layer has a function of injecting holes from the anode, a function of transporting holes, or a function of blocking electrons injected from the cathode. Anything should do. Specific examples thereof include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, and styryl anthracene derivatives , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds,
Examples thereof include poly (N-vinylcarbazole) derivatives, aniline-based copolymers, thiophene oligomers, and conductive polymer oligomers such as polythiophene. The thicknesses of the hole injection layer and the hole transport layer are not particularly limited, but are usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 5 μm.
00 nm. The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. Examples of the method for forming the hole injection layer and the hole transport layer include a vacuum deposition method, an LB method, and a method in which the hole injection / transport agent is dissolved or dispersed in a solvent and coated (spin coating method, casting method, dip coating method). Etc.) are used. In the case of the coating method, it can be dissolved or dispersed together with the resin component. Examples of the resin component include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, and poly (N -Vinyl carbazole), hydrocarbon resins, ketone resins, phenoxy resins, polyamides, ethyl cellulose, vinyl acetate, ABS resins, polyurethanes, melamine resins, unsaturated polyester resins, alkyd resins, epoxy resins, silicone resins, and the like.

The material of the electron injecting layer and the electron transporting layer is not limited as long as it has a function of injecting electrons from the cathode, a function of transporting electrons, or a function of blocking holes injected from the anode. Good. Specific examples thereof include triazole derivatives, oxazole derivatives, oxadiazole derivatives,
Heterocyclic tetracarboxylic anhydrides such as fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthalene perylene, and phthalocyanine derivatives And various metal complexes typified by metal complexes of 8-quinolinol derivatives, metal phthalocyanines, and metal complexes having benzoxazole or benzothiazole as ligands. The thickness of the electron injection layer and the electron transport layer is not particularly limited, but is usually 1 nm to 5 μm.
m, more preferably 5 nm to 1
μm, and more preferably 10 nm to 500 nm. The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-mentioned materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. Examples of the method for forming the electron injection layer and the electron transport layer include a vacuum deposition method, an LB method, and a method in which the electron injection and transport agent is dissolved or dispersed in a solvent and coated (spin coating, casting, dip coating, and the like). Is used. In the case of the coating method, it can be dissolved or dispersed together with the resin component. As the resin component, for example, those exemplified in the case of the hole injection transport layer can be applied.

As the material of the protective layer, any material may be used as long as it has a function of preventing a substance which promotes element deterioration such as moisture and oxygen from entering the element. As a specific example,
In, Sn, Pb, Au, Cu, Ag, Al, Ti, N
metal such as i, MgO, SiO, SiO ₂ , Al ₂ O ₃ ,
GeO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O
_3, a metal oxide such as TiO _2, MgF _2, LiF, Al
F ₃ , metal fluoride such as CaF ₂ , polyethylene, polypropylene, polymethyl methacrylate, polyimide,
Polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, copolymerizing a monomer mixture containing tetrafluoroethylene and at least one comonomer Copolymer obtained, a fluorine-containing copolymer having a cyclic structure in the copolymer main chain, a water-absorbing substance having a water absorption of 1% or more,
A moisture-proof substance having a water absorption of 0.1% or less can be used. There is no particular limitation on the method for forming the protective layer. For example, a vacuum deposition method, a sputtering method, a reactive sputtering method,
BE (molecular beam epitaxy) method, cluster ion beam method, ion plating method, plasma polymerization method (high frequency excitation ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method Applicable.

[0035]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Example 1 IT was placed on a 25 mm × 25 mm × 0.7 mm glass substrate.
O was formed to a thickness of 150 nm to obtain a transparent support substrate. After etching and washing the transparent support substrate, 40 mg of poly (N-vinylcarbazole), 1,1,4,4
0.5 mg of tetraphenylbutadiene and 12 mg of the compound shown in Table 1 were dissolved in 3 ml of 1,2-dichloroethane, and spin-coated on a washed ITO substrate. The thickness of the generated organic thin film was about 110 nm. Mask patterned on organic thin film (light emitting area is 5mm × 5m
m), and magnesium: silver = 10: 1 is co-deposited at 50 nm in a vapor deposition apparatus.
m was deposited. Using a source measure unit 2400 manufactured by Toyo Technica, a DC constant voltage is applied to the light emitting element to emit light, and the brightness is measured by a luminance meter BM-8 manufactured by Topcon Corporation, and the emission wavelength is measured by a spectrum analyzer PM manufactured by Hamamatsu Photonics.
It measured using A-11. In addition, the fabricated device was
C. and relative humidity at 20% relative humidity for 10 hours (relative value of luminance over time (drive voltage 15 V) when the luminance immediately after device production is assumed to be 100) and darkness of the light emitting surface. The presence or absence of spot generation was evaluated. Table 1 shows the results.

[0036]

[Table 1]

[0037]

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As is clear from the results shown in Table 1, in the device using the compound of the present invention, low-voltage driving and high-luminance luminescence can be performed even in a coating method in which the luminous luminance is lower than that of the comparative compound. I understand. Comparative compound 1 (PB
In the device using D), the luminance decreases significantly after aging at high temperature,
While the occurrence of dark spots was remarkably observed, the device of the present invention showed a small decrease in luminance and showed good surface light emission. Further, in the device using the comparative compound 2 (Alq), emission of Alq was mainly observed, and blue purity was reduced.
It turns out that the device using the compound of the present invention does not function effectively as a host material for blue light emission, but has high blue purity and functions as a good host material for blue light emission.

Example 2 An ITO substrate was etched and washed in the same manner as in Example 1, and then copper phthalocyanine (5 nm) and TPD (N, N-bis (3-methylphenyl) -N, N-diphenylbenzidine) 40 were used.
nm, Coumarin 6 and the compounds described in Table 2 were co-deposited at a deposition rate of 0.04 ° / sec and 4 ° / sec, respectively, to a film thickness of 60 nm. Next, a cathode was deposited in the same manner as in Example 1. Table 2 shows the results of the same evaluation as in Example 1.

[0040]

[Table 2]

[0041]

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As is evident from the results in Table 2, the device using the compound of the present invention can emit light with higher luminance even in the vapor deposition method than the comparative compound, and also has good durability. I understand.

Example 3 After etching and washing the ITO substrate in the same manner as in Example 1, copper phthalocyanine 5 nm, TPD (N, N-bis (3-methylphenyl) -N, N-diphenylbenzidine) 40
nm, Alq 20 nm and the compound 40 nm described in Table 3.
Were vacuum-deposited in this order. Next, a cathode was deposited in the same manner as in Example 1. Table 3 shows the results of the same evaluation as in Example 1.
Shown in

[0044]

[Table 3]

As is clear from the results shown in Table 3, the device using the compound of the present invention did not emit light after aging at high temperature and had a problem in durability, whereas the device using the compound of the present invention did not.
The device emits light even after aging at high temperature, indicating that the durability of the device is good.

Example 4 40 mg of poly (N-vinylcarbazole), 12 mg of Exemplified Compound 7 of the present invention, 1,1,4,4-tetraphenylbutadiene were deposited on an ITO glass substrate etched and washed in the same manner as in Example 1. 10 mg, Compound A 0.5 mg and Nile Red 0.1 mg were treated with 1,2-dichloroethane 3
The solution dissolved in ml was spin-coated. Next, a cathode was deposited in the same manner as in Example 1. When a DC voltage was applied to this device using the ITO electrode as the anode and the Mg: Ag electrode as the cathode, and the light emission characteristics were examined, the CIE chromaticity diagram at 15 V (x,
y) = (0.35, 0.35) white light emission (luminance 219)
0 cd / m ² ), which proved to be effective for white light emission.

[0047]

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[0048]

According to the present invention, high color purity, high brightness,
High-efficiency light emission is possible, and good light-emitting characteristics can be obtained even with a coating method with low light emission luminance, making it possible to produce an element that is advantageous in terms of manufacturing cost and the like. In addition, it is possible to produce a device with good durability in comparison with a conventional compound.

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[Procedure amendment]

[Submission date] November 24, 1998 (1998.11.
24)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

[0043]

Embedded image

Claims (4)

[Claims] 1. An organic light-emitting device material, which is a compound represented by the following general formula (I). Embedded image (Wherein R ¹ and R ² are each an aliphatic hydrocarbon group,
Represents an aryl group or a heterocyclic group. m represents 2 or 3. ) 2. An organic light emitting device having a light emitting layer or a plurality of organic compound thin films including the light emitting layer formed between a pair of electrodes, wherein at least one layer is a layer containing the organic light emitting device material according to claim 1. Organic light-emitting device. 3. An organic light emitting device in which a light emitting layer or a plurality of organic compound thin films including a light emitting layer is formed between a pair of electrodes, at least one of which is a layer in which the organic light emitting device material according to claim 1 is dispersed in a polymer. An organic light-emitting device, comprising: 4. An organic light-emitting element having a light-emitting layer or a plurality of organic compound thin films including the light-emitting layer formed between a pair of electrodes, wherein at least one layer is a layer containing the organic light-emitting element material according to claim 1; One electrode is silver and / or
Alternatively, an organic light-emitting device comprising gold.