JP2000286056A - Electroluminescent element material and electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an EL element material containing a compound having superior hole transporting ability and suitable for manufacture of a high- luminance coat-type organic EL element, and to obtain the organic EL element excellent in luminance though it is a coat type. SOLUTION: This EL element is made of an EL element material containing a carbazole derivative represented by the formula. In the formula, R1 is H, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, while R2-R9 are H, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, alkylthio groups, amino groups, alkylamino groups, dialkylamino groups, aryl groups, aryloxy groups, arylthio groups, arylamino groups, diarylamino groups, alkylarylamino groups or heterocyclic groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electroluminescent device material containing a specific carbazole derivative or a polymer thereof, and an electroluminescent device using the material.

[0002]

2. Description of the Related Art At present, research and development on various display elements are active. Among them, an organic electroluminescence element (EL element), which can obtain high-luminance light emission at a low voltage, has attracted attention as a promising display element. Have been. For example, an EL element that forms an organic thin film by vapor deposition of an organic compound is known (Applied Physics).
Letters, 51, p. 913-, (1987)). The organic EL device described in the document has a laminated structure of an electron transporting material and a hole transporting material, and its light emitting characteristics are greatly improved as compared with the conventional single-layer type device. As a hole transporting material used in the stacked device, a triarylamine derivative represented by TPD (N, N'-diphenyl-N, N'-ditolyl-benzidine) is generally used. Further, as a heterocyclic hole transport material, PVK (polyvinyl carbazole) is known, and its application examples have been reported in various systems to date. The inventors have also mentioned the above TPD and PV
We have been studying organic EL devices using K,
When the triarylamine derivative is used for a coating type device,
Even when the polymer was induced or the other polymer was dispersed as a binder, an element having a higher luminance than that of PVK could not be obtained. Also in the case of the coating type device using the PVK, a device having a satisfactory brightness was not obtained as compared with the performance of the TPD in the vapor deposition type device.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an EL device material containing a compound having a good hole transporting ability and suitable for producing an organic EL device having high luminance.

[0004]

According to the present invention, the following organic EL device material and organic EL device are provided, and the above object of the present invention is achieved.

(1) An electroluminescent device material containing a carbazole derivative represented by the following general formula (1).

[0006]

Embedded image

In the formula, R ₁ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group. R _{2 to} R ₉ are the same or different and each represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an amino group, an alkylamino group, a dialkylamino group, an aryl group, an aryloxy group, or an arylthio group. , An arylamino group, a diarylamino group, an alkylarylamino group, or a heterocyclic group, any one of which is a substituent other than a hydrogen atom. R ₂
Among R ₉ to R ₉ , two adjacent substituents may combine with each other to form a ring structure. (2) Among R _{2 to} R _{9 in} the general formula (1), a ring structure formed by bonding two adjacent substituents to each other forms an aromatic hydrocarbon ring or a thiophene ring, a furan ring, a pyrrole ring, The electroluminescent device material according to the above (1), which is a heteroaromatic ring having a ring skeleton selected from selenophene rings. (3) An electroluminescent device material containing a polymer formed by polymerization of the carbazole derivative represented by the general formula (1), wherein R _{1 in the} general formula (1) is a polymerizable group. (4) The electroluminescent device material according to (3), wherein R _{1 in the} general formula (1) is a vinyl group, and the polymer formed by polymerization is a poly-N-vinyl carbazole derivative. (5) A polymer formed by bonding between the molecules of the carbazole derivative represented by the general formula (1) via two or more groups selected from R _{1 to} R ₉ of the general formula (1). Electroluminescent device material to be contained. (6) (a) the carbazole derivative according to the above (1) or (2), or the polymer of the carbazole derivative according to any of the above (3) to (5), and (b) a polymer other than the polymer An electroluminescent device material containing at least one polymer. (7) An electroluminescent device material wherein the polymer (b) is a conjugated polymer. (8) At least one of the organic layers located between the anode and the cathode
An electroluminescent device, wherein the layer contains the electroluminescent device material according to claim 1. (9) The electroluminescent device according to the above (8), wherein the organic layer in which the electroluminescent device material is present is formed by coating.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The compound contained in the electroluminescent device material of the present invention is a carbazole derivative represented by the general formula (1). First, the carbazole derivative represented by the general formula (1) will be described. R ₁ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group. The alkyl group preferably has 1 to 30 carbon atoms, more preferably has 1 to 15 carbon atoms, and still more preferably has 1 to 8 carbon atoms. Specific examples include methyl, t-butyl, cyclohexyl and the like. The alkenyl group preferably has 2 to 30 carbon atoms, and more preferably has 2 to 2 carbon atoms.
15, more preferably 2 to 8 carbon atoms. Specifically, for example, vinyl, 1-propenyl, 1-butene-2-
Yl, cyclohexen-1-yl and the like.

The alkynyl group preferably has 2 to 30 carbon atoms, more preferably has 2 to 15 carbon atoms, and still more preferably has 2 to 8 carbon atoms. Specifically, for example, ethynyl, 1-propynyl and the like can be mentioned. The aryl group preferably has 6 to 30 carbon atoms, more preferably has 6 to 15 carbon atoms, and still more preferably has 6 to 1 carbon atoms.
2. Specific examples include phenyl, tolyl, xylyl, naphthyl, biphenylyl, pyrenyl and the like. The heterocyclic group preferably has 1 to 30 carbon atoms, more preferably has 2 to 15 carbon atoms, and still more preferably has 2 to 8 carbon atoms. Further, those having a 5- or 6-membered ring are preferable, and may be condensed with another ring. Examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples of the hetero ring include, for example, pyridyl, piperidyl, oxazolyl, oxadiazolyl, tetrahydrofuryl, thienyl and the like.

Among them, a hydrogen atom, an aryl group and a heterocyclic group are particularly preferred.

The above groups may further have a substituent. A polymer in which the substituent is a polymerizable group and the compound represented by the general formula (1) is one of the monomers can be a component of the EL device material. In particular, when R ₁ is an alkenyl group, a poly N-vinyl carbazole derivative obtained by polymerizing the carbazole derivative of the general formula (1) is suitable as a component of an EL device material. Further, a copolymer obtained by copolymerizing with another monomer at the time of polymerization can also be a component of the EL element material. Furthermore, 2 selected from R _{1 to} R ₉
A polymer formed by bonding between molecules via one or more groups is also suitable as a component of an EL device material.

R _{2 to} R ₉ are the same or different and each represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an alkylthio group, an amino group, an alkylamino group, an aryloxy group, an arylthio group, Represents an arylamino group, a diarylamino group, an alkylarylamino group, or a heterocyclic group. However, R _{2 to} R ₉
Is a group other than a hydrogen atom.

The alkyl group preferably has 1 to 30 carbon atoms, more preferably has 1 to 15 carbon atoms, and still more preferably has 1 to 8 carbon atoms. Specific examples include methyl, t-butyl, cyclohexyl and the like. The alkenyl group preferably has 2 to 30 carbon atoms, more preferably has 2 to 15 carbon atoms, and still more preferably has 2 to 8 carbon atoms. Specifically, for example, vinyl, 1-
Probenyl, 1-buten-2-yl, cyclohexen-
1-yl and the like. The alkynyl group preferably has 2 to 30 carbon atoms, more preferably 2 carbon atoms.
-15, more preferably 2-8 carbon atoms. Specifically, for example, ethynyl, 1-propynyl and the like can be mentioned. The aryl group preferably has 6 to 30 carbon atoms, more preferably has 6 to 15 carbon atoms, and still more preferably has 6 to 12 carbon atoms. Specific examples include phenyl, tolyl, xylyl, naphthyl, pipenyl, pyrenyl and the like.

The alkoxy group preferably has 2 to 30 carbon atoms, more preferably has 2 to 15 carbon atoms, and still more preferably has 2 to 8 carbon atoms. Specific examples include a methoxy group, an ethoxy group, a butoxy group, an octyloxy group, and a 2-ethylhexyloxy group. The alkylthio group preferably has 2 to 30 carbon atoms, more preferably has 2 to 15 carbon atoms, and still more preferably has 2 to 8 carbon atoms. Specific examples include a methylthio group, an ethylthio group, a butylthio group, an octylthio group, and the like. The amino group and the alkylamino group preferably have 2 to 30 carbon atoms, more preferably have 2 to 15 carbon atoms, and still more preferably have 2 to 8 carbon atoms.
It is. Specific examples include a methylamino group, an ethylamino group, a butylamino group, a phenoxypropylamino group, a dimethylamino group, a diethylamino group, a dibutylamino group, a piperidino group, and a morpholino group.

The aryloxy group may have 6 to 3 carbon atoms.
0 is preferable, and more preferably 6 to 15 carbon atoms,
More preferably, it has 6 to 8 carbon atoms. Specific examples include a phenoxy group and a tolyloxy group. The arylthio group preferably has 6 to 30 carbon atoms, more preferably has 6 to 15 carbon atoms, and still more preferably has 6 to 8 carbon atoms. Specific examples include a phenylthio group. The arylamino group preferably has 6 to 30 carbon atoms, more preferably has 6 to 15 carbon atoms, and still more preferably has 6 to 8 carbon atoms. Specific examples include an anilino group and a toluidino group. The diarylamino group preferably has 12 to 30 carbon atoms, more preferably has 12 to 20 carbon atoms, and still more preferably has 12 to 15 carbon atoms. Specifically, for example, a diphenylamino group and the like can be mentioned.

An alkylarylamino group (preferably having 7 to 30 carbon atoms, more preferably having 7 to 15 carbon atoms, still more preferably having 7 to 8 carbon atoms, for example, an N-methylanilino group, an N-ethylanilino group, etc. As the ring group, those having 2 to 30 carbon atoms are preferable, more preferably 2 to 15 carbon atoms, and still more preferably 4 to 8 carbon atoms.
It is. Specific examples include a pyrrole group and a furan group.

Among R _{2 to} R ₉ , two adjacent substituents may be bonded to each other to form a ring structure such as a cyclic hydrocarbon, an aromatic ring, a hetero ring, or a hetero aromatic ring. A particularly preferred ring structure is an aromatic hydrocarbon ring or a heteroaromatic ring having a ring skeleton selected from thiophene, furan, pyrrole, and selenophene.

R _{1 to} R ₉ can be further substituted with a substituent. Examples of the substituent include the following groups. Alkyl group: preferably 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methyl, ethyl, iso-propyl, ter
t-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl and the like. Alkenyl group: preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms, for example, vinyl, allyl, 2-butenyl, 3-pentenyl and the like. Alkynyl group: preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms, such as propargyl and 3-pentynyl.

Aryl group: preferably having 6 to 30 carbon atoms
More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, P-methylphenyl, and naphthyl. Alkoxy group: preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methoxy, ethoxy, butoxy, tert
-Butoxy, 2-ethylhexyloxy, dodecyloxy and the like. Amino group: preferably having 0 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms, for example, dimethylamino, methylcarbamoyl, ethylsulfonylamino, dimethylaminocarbonylamino, phthalimide And the like. Heterocyclic group: preferably containing an enzyme atom, sulfur atom, or nitrogen atom, preferably having 1 to 50 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 2 to 2 carbon atoms.
12, for example, imidazolyl, pyridyl, furyl,
Examples include piperidyl, morpholino, benzoxazolyl, and triazolyl.

Aryloxy group: preferably having 6 to 6 carbon atoms
20, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenoxy and naphthyloxy. Alkylthio group: preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms
And examples thereof include a methylthio group and the like. Arylthio group: preferably 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms
And, for example, phenylthio and the like. Others: a hydroxy group, a halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, among which a fluorine atom is particularly preferable), a thiol group and the like.

Among these substituents, preferred are an alkyl group, an aryl group and an alkoxy group.

The carbazole derivative represented by the general formula (1) can be synthesized by a known method. Most commonly,
Az of arylhydrazine and cyclohexanone derivative
After the a-Cope rearrangement reaction, synthesis by dehydroaromatization, synthesis by denitrogenation cyclization of biphenyl-2-azide, synthesis by reductive cyclization of 2-nitrobiphenyl with triethyl phosphite, and the like. be able to. The general synthesis scheme is shown below. Then, specific examples of the carbazole derivative represented by the general formula (1) and a polymer thereof will be illustrated. The invention is not limited by this embodiment.

[0023]

Embedded image

[0024]

Embedded image

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image

[0028]

Embedded image

[0029]

Embedded image

[0030]

Embedded image

The carbazole derivative represented by the general formula (1) and a polymer thereof can be used alone or in combination with another polymer. As examples of the polymer, various polymers such as a hydrocarbon polymer, polyester, polyamide, and acrylic resin can be used, and among them, a conjugated polymer is preferable. Examples of the conjugated polymer include a polypyrrole polymer, a polythiophene polymer, a polyphenylene polymer, a polyfluorene polymer, and a polyphenylenevinylene polymer. Above all, Cambridge
A polyphenylenevinylene-based polymer proposed by Dispayay Technology can be preferably used. Regarding this polyphenylene vinylene polymer, ORGANIC EL
ECTROLUMINESCENT MATERIALS AND DEV1CES (Gordon and
Breach Publishers, 1997) pp. 73-. Examples of the conjugated polymer that can be used in the present invention are listed below, but the present invention is not limited by these specific examples.

[0032]

Embedded image

[0033]

Embedded image

Further, the carbazole derivative represented by the general formula (1) can be used as a laminated structure with another polymer by a coating method. Furthermore, it can be used by a method such as mixing with a low molecular weight compound or laminating. In the case of forming a laminated structure, a method in which a low-molecular compound is mixed with a polymer binder and applied can be adopted. Further, the layers can be laminated by a method such as vacuum deposition or sputtering.

When the carbazole derivative represented by the general formula (1) is used as a polymer, the preferred range of the molecular weight is as follows:
It is 500 to 10,000,000, particularly preferably in the range of 1,000 to 1,000,000.

Next, an E having an organic layer containing a carbazole derivative represented by the general formula (1) or a polymer thereof is used.
The L element will be described. The method for forming the organic layer of the EL element is not particularly limited, but methods such as resistance heating evaporation, electron beam, sputtering, molecular lamination, and coating are used. Resistance heating evaporation and coating methods are particularly preferred.

The EL element of the present invention is an element in which an organic layer, specifically a light emitting layer or a plurality of organic compound thin films including the light emitting layer, is formed between a pair of electrodes of an anode and a cathode. It may have an injection layer, a hole transport layer, 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), and metals such as gold, silver, chromium, and nickel.
Further, mixtures or laminates of these metals and conductive metal oxides, 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, and a conductive metal oxide is preferable, and ITO is particularly preferable in terms of productivity, high conductivity, transparency, and the like. The thickness of the anode can be appropriately selected depending on the material.
It is preferably in the range of nm to 4 μm, more preferably 50 nm to 1 μm, and still more preferably 100 nm to 4 μm.
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 using glass,
In order to reduce ions eluted from the glass, it is preferable to use an alkali-free 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, but when glass is used, it is usually 0.2 mm or more, preferably 0.1 mm or more.
Use a thing of 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 vapor deposition method, a chemical reaction method (such as a sol-gel method), and a dispersion of indium tin oxide are applied. The film is formed by the method described above. The anode can be washed or otherwise treated to lower the driving voltage of the device or increase the luminous efficiency. For example, in the case of ITO, UV-ozone treatment, plasma treatment and the like are effective.

The cathode supplies electrons to the electron injecting layer, the electron transporting layer, the light emitting layer, etc., and provides the adhesiveness between the negative electrode and the adjacent layer, such as the electron injecting layer, the electron transporting layer, the light emitting layer, the ionization potential, and the like. It is selected in consideration of stability and the like. As a material for the cathode, a metal, an alloy, a metal halide, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples thereof include an alkali metal (for example, L
i, Na, K, etc.) and their fluorides, alkaline earth metals (eg, Mg, Ca, etc.) and their 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 It is a material having a work function of 4 eV or less, more preferably aluminum, lithium-
An aluminum alloy or a mixed metal thereof, a magnesium-silver alloy or a mixed metal thereof, or the like is used. The cathode is
Not only a single-layer structure of the compound and the mixture but also a stacked structure including the compound and the mixture can be employed.
The thickness of the cathode can be appropriately selected depending on the material.
It is preferably in the range of 0 nm to 4 μm, more preferably 50 nm to 1 μm, and still more preferably 100 nm.
１1 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 evaporated simultaneously. Furthermore, it is also possible to form an alloy electrode by simultaneously depositing a plurality of metals,
Alternatively, a previously adjusted alloy may be deposited. The sheet resistance of the anode and the cathode is preferably low, and several hundred Ω /
□ The following is preferred.

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 a metal complex, but other light emitting materials 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 , Metal complexes and rare earth complexes of pyrrolidine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, cyclopentadiene derivatives, styrylamine derivatives, aromatic dimethylidin compounds, 8-quinolinol derivatives Polymer compounds such as polythiophene, polyphenylene, polyphenylenevinylene, etc. And the like. The thickness of the light emitting layer is not particularly limited, but is 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 500 nm. The method for forming the light-emitting layer is not particularly limited, but resistance heating evaporation, electron beam, sputtering, molecular lamination,
A coating method (such as a spin coating method, a casting method, or a dip coating method) and an LB method are used, and resistance heating evaporation and a coating method are preferable.

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. Should be fine. 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, styryl anthracene derivatives , Fluorenone derivative, hydrazone derivative, stilbene derivative, silazane derivative, aromatic tertiary amine compound, styrylamine compound, aromatic dimethylidin compound, porphyrin compound, polysilane compound,
Examples include poly- (N-vinylcarbazole) derivatives, aniline-based copolymers, thiophene oligomers, and conductive polymer oligomers such as polythiophene. In the present invention, a carbazole derivative represented by the general formula (1) or a polymer thereof is preferably used.

The thickness of the hole injection layer and the hole transport layer is not particularly limited, but is usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm.
More preferably, it is 10 nm to 500 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. As a method for forming the hole injection layer and the hole transport layer, a vacuum evaporation method or L
The B method and a method of coating by dissolving or dispersing the hole injecting and transporting agent in a solvent (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 resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose,
Examples include vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, and silicone resin.

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 metal complexes, triazole derivatives, oxazole derivatives, oxadiazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives,
Thiopyran dioxide derivative, carbodiimide derivative,
Metal complexes of heterocyclic tetracarboxylic anhydrides such as fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthalene perylene, phthalocyanine derivatives, 8-quinolinol derivatives, and metal complexes having metal phthalocyanine, benzoxazole or benzothiazole as ligands Various known metal complexes and the like can be cited as known compounds. The carbazole derivative of the general formula (1) and a polymer thereof can be used as the electron transporting material or the electron injecting material. The thickness of the electron injecting layer and the electron transporting layer is not particularly limited, but is 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 500 nm. The electron injecting layer and the electron transporting layer may have a single-layer structure composed of a combination of one or more of the above-mentioned carbazole derivatives or polymers thereof, or a combination of the above-mentioned carbazole derivatives or polymers and the above-mentioned known compounds. Alternatively, a multi-layer structure including a plurality of layers having the same composition or different compositions may be used.

The electron injecting layer and the electron transporting layer may be formed by vacuum evaporation, LB, or by dissolving or dispersing the above electron injecting and transporting agent in a solvent and coating (spin coating, casting, dip coating). Etc.) are used. In the case of the coating method, a polymer of the carbazole derivative can be used, or it can be dissolved or dispersed together with a resin component. As the resin component in this case, for example, the case of the hole injection transport layer is exemplified. Things can be applied.

As the material of the protective layer, any material can 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
i, etc., MgO, SiO, SiO ₂ , Al ₂ O ₃ ,
Metal oxides such as GeO, Fe ₂ O ₃ , Y ₂ O ₃ and TiO ₂ , metal fluorides such as MgF ₂ , LiF, AlF ₃ and CaF ₂ , polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetra Fluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, and a copolymer obtained by copolymerizing a monomer mixture containing tetrafluoroethylene and at least one comonomer. Polymer, a fluorinated 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, and the like are included.

The method for forming the protective layer is not particularly limited. For example, a vacuum deposition method, a sputtering method, a reactive sputtering method, an MBE (molecular beam epitaxy) method, a cluster ion beam method, an ion plating method, a plasma polymerization method ( High frequency excitation ion plating), plasma CVD, laser CVD, thermal CVD, gas source CVD, and coating are applicable.

[0048]

EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the scope of the present invention is not limited to the examples.

<Preparation and Evaluation of Organic EL Element> Comparative Example 1 A washed ITO substrate was set in a vapor deposition apparatus, and TPD
(N, N′-diphenyl-N, N′-ditolyl-benzidine) was deposited to a thickness of 40 nm and Alq (tris- (8-hydroxyquinolinato) aluminum) to a thickness of 60 nm. Mask patterned on organic thin film (light emitting area is 5mm ×
5 mm), and magnesium: silver = 10: 1 was 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 organic EL element to emit light, and the luminance is measured by a luminance meter BM- manufactured by Topcon Corporation.
8. The emission wavelength was measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. When a voltage of 12 V was applied, green light emission of ELmax: 520 nm was obtained, and the maximum luminance was 5,500 cd / m ² (8 V).

[0050]

Embedded image

Comparative Example 2 A cleaned ITO substrate was placed in a vapor deposition apparatus,
The material A was vapor-deposited at 40 nm and Alq was vapor-deposited at 60 nm. Organic thin film
Patterned mask on top (emission area 5mm x 5m
m) and set the magnesium in the vapor deposition device.
After silver: 10: 1 is co-deposited with 50 nm, silver is 50 nm
Was deposited. When a voltage of 12 V was applied, ELma
x: green light emission of 520 nm was obtained, and the highest luminance was 122
0 cd / m ^Two(12 V).

[0052]

Embedded image

Comparative Example 3 PVK (poly-N-vinylcarbazole) (40 mg), coumarin (60.5 mg), and PBD (12 mg) were dissolved in 1,2-dichloroethane (2 ml), and the solution was applied to a washed ITO substrate by using a spin coater. While adjusting
It was applied so that the film thickness became 100 nm. The coated substrate is placed in a vapor deposition device and patterned on an organic thin film (a mask having a light emitting area of 5 mm × 5 mm).
Is installed, and magnesium: silver = 10: 1 in the vapor deposition apparatus.
Was co-evaporated to 50 nm, and then 50 nm of silver was evaporated. 18
When a voltage of V was applied, green light emission of ELmax: 525 nm was obtained, and the maximum luminance was 1055 cd / m ² (1
8V).

[0054]

Embedded image

Comparative Example 4 The conjugated polymer HT-440 mg described in the present specification was dissolved in chloroform 2 ml, and this solution was washed on an ITO substrate using a spin coater to adjust the film thickness to 100 μm in the same manner as in Comparative Example 3. Was applied. After magnesium and silver were deposited on the substrate in the same manner as in Comparative Example 3, the device was evaluated. When a voltage of 10 V was applied, ELmax was 595 nm.
And the maximum brightness is 2200 cd / m
² (10 V).

Example 1 A device was prepared and evaluated in the same manner as in Comparative Example 1, except that the carbazole derivative CZ-4 of the general formula (1) was used instead of the compound A of Comparative Example 2. When a voltage of 10 V was applied, E
Lmax: green light emission of 520 nm was obtained, and the maximum luminance was 3950 cd / m ² (10 V).

Example 2 Instead of the compound A of Comparative Example 2, the compound of the general formula (1) was used.
Using a rubazole derivative CZ-13,
A child was prepared and evaluated. When a voltage of 9 V was applied, EL
max: green light emission of 520 nm was obtained, and the highest luminance was 4
950 cd / m ^Two(9V).

Example 3 A device was prepared and evaluated in the same manner as in Comparative Example 1, except that the carbazole derivative CZ-17 represented by the general formula (1) was used instead of the compound A in Comparative Example 2. When a voltage of 9 V was applied, E
Lmax: green light emission of 520 nm was obtained, and the maximum luminance was 5890 cd / m ² (8 V).

Example 4 A device was prepared and evaluated in the same manner as in Comparative Example 3, except that the polymer PCZ-1 of the carbazole derivative represented by the general formula (1) was used instead of the PVK of Comparative Example 3. When a voltage of 16 V was applied, green light emission of ELmax: 525 nm was obtained, and the maximum luminance was 3150 cd / m ² (16 V).

Example 5 A device was prepared and evaluated in the same manner as in Comparative Example 3, except that the polymer PCZ-7 of the carbazole derivative represented by the general formula (1) was used instead of the PVK of Comparative Example 3. When a voltage of 15 V was applied, green light emission of ELmax: 525 nm was obtained, and the maximum luminance was 4,200 cd / m ² (15 V).

Example 6 Instead of HT-4 of Comparative Example 4, a mixed solution in which the carbazole derivative polymer PCZ-1 of the above general formula (1) and the conjugated polymer HT-4 were dissolved in an equal weight was 100 nm.
Using the coated material, a device was prepared and evaluated in the same manner as in Comparative Example 3. When a voltage of 10 V was applied, ELmax: 5
95nm orange light emission with maximum brightness of 6720cd
/ M ² (10 V).

Example 7 Instead of the PVK of Comparative Example 3, a mixed solution in which the carbazole derivative polymer PCZ-17 of the general formula (1) and the conjugated polymer HT-4 were dissolved in an equal weight by 100 nm was used.
Using the coated material, a device was prepared and evaluated in the same manner as in Comparative Example 3. When a voltage of 9 V was applied, Elmax: 59
An orange emission of 5 nm was obtained, and its maximum luminance was 5300 cd /
m ² (9 V).

From the results shown in the above Examples and Comparative Examples, the EL device using the EL device material containing the carbazole derivative represented by the general formula (1) or a polymer thereof has high luminance. It is clear that the EL element has high luminance even when it is a coating type.

[0064]

The EL device material of the present invention contains a carbazole derivative represented by the general formula (1) having a good hole transporting ability or a polymer thereof, and is used to produce a high-luminance organic EL. An element can be manufactured.

Claims (9)

[Claims] 1. An electroluminescent device material containing a carbazole derivative represented by the following general formula (1). Embedded image In the formula: R ₁ is a hydrogen atom, an alkyl group, an alkenyl group,
Represents an alkynyl group, an aryl group, or a heterocyclic group.
R _{2 to} R ₉ are the same or different and each represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an amino group, an alkylamino group, a dialkylamino group, an aryl group, an aryloxy group, or an arylthio group. , An arylamino group, a diarylamino group, an alkylarylamino group, or a heterocyclic group, any one of which is a substituent other than a hydrogen atom. Among R _{2 to} R ₉ , two adjacent substituents may combine with each other to form a ring structure. 2. A ring structure formed by bonding two adjacent substituents among R _{2 to} R _{9 in} the general formula (1) to form an aromatic hydrocarbon ring, a thiophene ring, a furan ring, or a pyrrole ring. The electroluminescent device material according to claim 1, which is a heteroaromatic ring having a ring skeleton selected from a ring and a selenophene ring. 3. An electroluminescent device material comprising a polymer formed by polymerization of a carbazole derivative represented by the general formula (1), wherein R _{1 in the} general formula (1) is a polymerizable group. 4. The electroluminescent device material according to claim 3, wherein R _{1 in the} general formula (1) is a vinyl group, and the polymer formed by polymerization is a poly-N-vinyl carbazole derivative. 5. A polymer formed by bonding the carbazole derivative represented by the general formula (1) between molecules via two or more groups selected from R _{1 to} R _{9 in} the general formula (1). An electroluminescent device material containing coalescence. 6. A carbazole derivative according to claim 1 or 2, or a polymer of the carbazole derivative according to any one of claims 3 to 5, and (b) at least one polymer other than the polymer. Electroluminescent device material containing species. 7. An electroluminescent device material wherein the polymer (b) is a conjugated polymer. 8. An electroluminescent device comprising the electroluminescent device material according to claim 1 in at least one of the organic layers located between the anode and the cathode. 9. The electroluminescent device according to claim 8, wherein the organic layer in which the electroluminescent device material is present is formed by coating.