JPH09263754A - Organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organic electroluminescent element having the capability of low-voltage drive, high luminance and high luminous efficiency by sandwiching an organic layer containing a hole transport material containing a specified polysilane compound and a luminescent material between a pair of electrodes. SOLUTION: This element is obtained by sandwiching an organic layer containing a hole transport material containing a polysilane compound [e.g. poly(ethyl(4-(N,N-diphenylamino)phenyl)silane] having a main chain comprising structural units represented by formulas I and II (wherein R1 , R2 , R3 and R4 are each an alkyl, a cycloalkyl, an aryl or an aralkyl; Ar1 is an arylene; and Ar2 is an aryl), satisfying the relationships: 0.2<=Z<=1 (wherein Z and 1-Z are the ratios of the numbers of structural units of formulas I and II to the total number of the structural units, respectively), and having an average molecular weight of 5,000 of above and a hole drift mobility of 10<-3> to 10<-1> cm<2> /Vsec and a luminescent material between a pair of electrodes at least either of which is transparent or translucent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence element (hereinafter sometimes referred to as an organic EL element) used for a surface light source or a display.
Specifically, it relates to an organic EL element having a hole transport material containing a polysilane compound.

[0002]

2. Description of the Related Art Inorganic electroluminescent devices (hereinafter sometimes referred to as inorganic EL devices) using an inorganic phosphor as a light emitting material are used for display devices such as a planar light source as a backlight and a flat panel display. However, high voltage AC was required to emit light.

In recent years, Tang et al. Have an organic E dye having a two-layer structure in which an organic fluorescent dye is used as a light emitting layer and an organic hole transporting compound used in a photoconductor for electrophotography is laminated.
L element is manufactured and driven by low voltage, high efficiency and high brightness.
An L element has been realized (Japanese Patent Laid-Open No. 59-194393).

Compared with inorganic EL elements, organic EL elements are characterized by low voltage driving, high brightness, and the ability to easily obtain light emission of a large number of colors. Many attempts have been reported for fluorescent dyes [Japanese Journal of Applied Physics (Jpn. J. Appl. Phys.)].
27, L269 (1988)], [Journal of Applied Physics (J. Appl. Ph.
ys. ) 65, 3610 (1989)].

The organic EL element is composed of a structure in which an organic light emitting material is sandwiched by a pair of opposing electrodes, and electrons are injected from one electrode and holes are injected from the other electrode. Light emission occurs when the injected electrons and holes recombine in the light emitting material.

The hole transport layer has a function of facilitating the injection of holes from the anode, easily transports holes due to the large hole drift mobility, and blocks electrons due to the small electron drift mobility, so that the hole transport layer is used in the light emitting layer. Has the function of increasing the recombination probability of. Therefore, in order to obtain an organic EL device having a low driving voltage, high brightness, and high luminous efficiency, a hole transporting compound having a high hole drift mobility is desired.

Up to now, a low molecular weight organic photoconductor has been often used as a hole transporting compound used in the hole transporting layer, and its hole drift mobility is also 10 ⁻³ cm ² / Vsec.
It has been known to some extent and has obtained a fairly high brightness, but since the organic photoconductor is easily crystallized by heat generation, it has low durability and lacks stability, and it is manufactured by vacuum deposition to form a film. High costs are a problem.

As the material used for the hole transport layer, it is also possible to use a low molecular weight organic photoconductor dispersed in a resin such as polycarbonate. In this case, the cost is low because the film can be formed by coating, but the hole drift mobility becomes low and the brightness does not become high.

As a high molecular weight material having a hole transporting property, poly (N-vinylcarbazole) (hereinafter referred to as PVCz) is used.
May be abbreviated. ) Is known, and it has been shown that a device in which PVCz and a polymer binder containing a luminescent agent (coumarin 7) are laminated emits green light (JP-A-4-2096).

Furthermore, an element in which PVCz and tris (8-quinolinol) aluminum as a light emitting material are laminated is shown (Japanese Patent Laid-Open No. 19908/1993). PV
Cz is low cost because it can be formed by coating.
Although crystallization due to heat generation does not easily occur, the hole drift mobility is remarkably low at 10 ⁻⁶ cm ² / Vsec, so that the luminous efficiency and brightness are not sufficient and the driving voltage is high.

In recent years, attention has been paid to polysilane compounds having silicon as a main skeleton. The polysilane compound is not only soluble in an organic solvent and excellent in film-forming property, but also has a property as a semiconductor in which holes are conducted by delocalized electron transfer through a main chain silicon-silicon bond. Because of its possession, it has come to be expected as an organic electronic material [Physical Rev
iew B) 35 (1987) 2818].

In particular, phenylmethylpolysilane is known to have the highest hole drift mobility as a polymer-only material, reaching about 10 ⁻⁴ cm ² / Vsec at room temperature (about 25 ° C.). However, at present, no polysilane compound including phenylmethylpolysilane has a hole drift mobility of 10 ⁻³ cm ² / Vsec or more at room temperature.

The use of a conventionally known polysilane compound in the hole transport layer of an organic EL device is disclosed in Japanese Patent Laid-Open No. 2-2.
As disclosed in Japanese Patent Publication No. 04996, these polysilane compounds have a hole drift mobility lower than that of a vapor-deposited film of an organic photoconductor having a low molecular weight, and therefore the brightness is not always sufficient.

[0014]

The object of the present invention is to solve the above-mentioned problems of the conventional organic EL device, and to provide an organic EL device having characteristics of higher luminance and higher luminous efficiency at a lower driving voltage.
An L element is provided.

[0015]

In view of the above circumstances, the inventors of the present invention have made extensive studies in order to further improve the light emission characteristics of an organic EL device using a polysilane compound as a hole transport material. By using a polysilane compound having an improved hole drift mobility by introducing an arylaminoarylene group as a hole transport material, an organic EL device having characteristics of low driving voltage, high brightness, and high luminous efficiency can be obtained. The present invention has been completed and the present invention has been completed.

The present invention relates to the following organic electroluminescent device. [1] An organic material having at least one organic layer between a pair of electrodes, at least one of which is transparent or translucent, and the organic layer includes a hole transport material and a light emitting material in the same layer or different layers. In the electroluminescent element, the hole transport material has a main chain skeleton represented by the following general formula (1).

[0017]

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[In the formula, R ₁ and R ₂ each independently represent an optionally substituted alkyl group, cycloalkyl group, aryl group or aralkyl group. Ar ₁ represents an optionally substituted arylene group, and Ar ₂ represents an optionally substituted aryl group. ] The repeating structural unit represented by the following general formula (2)

[0019]

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[In the formula, R ₃ and R ₄ each independently represent an optionally substituted alkyl group, cycloalkyl group, aryl group or aralkyl group. ] The ratio of the number of repeating structural units (1) and (2) to the total number of repeating structural units (1) and (2) is z and 1 respectively.
-Z, 0.2 ≦ z ≦ 1, the weight average molecular weight is 5000 or more, and the hole drift mobility is 1.
An organic electroluminescence device, which is a hole-transporting material containing a polysilane compound of 0 ⁻³ to 10 ⁻¹ cm ² / Vsec.

[2] In the general formula (1), R ₂ is an optionally substituted phenyl group, Ar ₁ is an optionally substituted phenylene group, and Ar ₂ is an optionally substituted phenyl group. The organic electroluminescence device of [1], which uses a polysilane compound.

[3] At least one organic layer is provided between a pair of electrodes, at least one of which is transparent or semi-transparent, and the organic layer is in the same layer or in another layer, and the hole transport material and the light emitting material. In an organic electroluminescence device containing a compound, which has fluorescence in a solid state as a light emitting material, contains one or more kinds of repeating units represented by the following formula (3), and the total of these repeating units is 50 mol% of all repeating units. Above, the number average molecular weight in terms of polystyrene is 1
The organic electroluminescence device according to [1] or [2], which contains at least one polymeric fluorescent substance of 0 ³ to 10 ⁷ .

[0023]

[Chemical 6]

[Here, Ar ₃ represents an arylene group or a heterocyclic compound group having 4 to 20 carbon atoms involved in a conjugated bond. R ₅ and R ₆ are independently hydrogen, an alkyl group having 1 to 20 carbon atoms, and 6 to 6 carbon atoms.
A group selected from the group consisting of an aryl group having 20 carbon atoms, a heterocyclic compound group having 4 to 20 carbon atoms and a cyano group is shown. ]

[4] A hole transporting layer containing at least one polysilane compound according to [1] or [2] and a light emitting layer are laminated, [1], [2] or [2]. [3] The organic electroluminescence device as described above.

[5] A hole transport layer containing one or more kinds of polysilane compounds described in [1] or [2], a light emitting layer and an electron transport layer are laminated [1] and [1]. 2], [3] or [4], the organic electroluminescence device.

[6] One or more organic layers containing a hole transport material containing one or more kinds of polysilane compounds described in [1] or [2] and a light emitting material are included [ 1], [2] or [3]] the organic electroluminescent element.

[7] One or more organic layers containing a hole transport material, a light emitting material and an electron transport material containing one or more polysilane compounds described in [1] or [2]. The organic electroluminescence device according to the above [1], [2] or [3]. Hereinafter, the organic EL device of the present invention will be described in detail.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The organic EL device of the present invention has at least a hole transport material and a light emitting material between electrodes composed of a pair of an anode and a cathode, at least one of which is transparent or semitransparent, The transport material is characterized by containing a polysilane compound having a specific structure.

The optionally substituted arylene group Ar ₁ of the arylaminoarylene group as a side chain in the polysilane compound used as the hole transport material of the organic EL device of the present invention has 6 to 24 carbon atoms. Are preferred, and examples thereof include an optionally substituted phenylene group, a naphthylene group, an anthrylene group and the like, and an optionally substituted phenylene group is preferable. Further, an optionally substituted aryl group Ar ₂
As the aryl group, an aryl group having 6 to 24 carbon atoms is preferable, and examples thereof include an optionally substituted phenyl group, a naphthyl group and an anthryl group, and an optionally substituted phenyl group is preferable.

As R ₂ in the arylaminoarylene group as a side chain, a linear or branched alkyl group having 1 to 10 carbon atoms which may be substituted, or an optionally substituted 10 Cycloalkyl groups having up to and including 6 carbon atoms, optionally substituted aryl groups having 6 to 24 carbon atoms or optionally substituted 7
Aralkyl groups having ~ 26 carbon atoms are preferred,
An aryl group having 6 to 24 carbon atoms which may be substituted is more preferable, and a phenyl group which may be substituted is particularly preferable.

Here, as the alkyl group, for example, methyl group, ethyl group, n-propyl group, isopropyl group,
An n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a dodecyl group and the like, a cycloalkyl group, for example, a cyclohexyl group and the like, and an aryl group, for example, phenyl. Examples of the aralkyl group include a group, a naphthyl group and an anthryl group, and examples of the aralkyl group include a benzyl group, a phenethyl group and a p-methylbenzyl group.

Here, an optionally substituted arylene group Ar ₁ , an optionally substituted aryl group Ar ₂ and an optionally substituted R _2, which is an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. The substituent is preferably a linear or branched alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 6 or less carbon atoms, and a methyl group, an ethyl group, an n-propyl group. , Isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group,
And cyclohexyl group.

Characteristic of the polysilane compound of the present invention,
Specific examples of the arylaminoarylene group, which is the side chain of the repeating structural unit represented by the general formula (1), are shown below, but the invention is not limited to these groups. In the formula, R _{1 to} R ₇
Each independently represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclohexyl group or the like. Also, n is an integer from 0 to 2, o is an integer from 0 to 3, p is an integer from 0 to 4, and q is
Represents an integer from 0 to 5.

[0035]

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The side chains R ₁ , R ₃ and R ₄ other than the arylaminoarylene group in the polysilane compound used as the hole transport material of the organic EL device of the present invention may be independently substituted 1 A linear or branched alkyl group having 10 to 10 carbon atoms, an optionally substituted cycloalkyl group having 10 or less carbon atoms, or an optionally substituted 6 to 24 carbon atoms Having an aryl group, optionally substituted 7 to 26
Aralkyl groups having 4 carbon atoms are preferred.

Specific examples of the alkyl group include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group and octyl group. Groups, dodecyl groups, etc., as cycloalkyl groups, for example, cyclohexyl groups, etc., as aryl groups, for example, phenyl groups, naphthyl groups, anthryl groups, etc., and as aralkyl groups, for example, benzyl groups, phenethyl groups. , P-methylbenzyl group and the like.

The substituent of the optionally substituted alkyl group, cycloalkyl group, aryl group and aralkyl group is a linear or branched alkyl group having 1 to 6 carbon atoms or 6 or less. Examples of the cycloalkyl group having a carbon atom include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group and a cyclohexyl group. Can be mentioned.

The ratio of the number of repeating structural units (1) and (2) to the total number of repeating structural units (1) and (2) of the polysilane compound used as the hole transporting material of the organic EL device of the present invention. Z and 1 respectively
Assuming −z, z is 0.2 ≦ z ≦ 1, preferably 0.
The range is 5 ≦ z ≦ 1, and more preferably z = 1.

The weight average molecular weight of the polysilane compound used as the hole transport material of the organic EL device of the present invention is 5
000 or more, preferably 10,000 or more, more preferably 100,000 or more. Weight average molecular weight is 500
When it is less than 0, the moldability, which is a characteristic of the polymer, is significantly reduced.

The hole drift mobility of the polysilane compound used as the hole transport material of the organic EL device of the present invention is 10 ^-3 to 10 ^-1 cm ² / Vsec. When the hole drift mobility is less than 10 ⁻³ , the high level emission characteristics targeted by the present invention cannot be achieved.

The polysilane compound used in the hole transport layer of the organic EL device of the present invention is prepared by a method known as the Kipping method, for example, Journal of Organometallic Chemistry.
Ganometallic Chemistry) No. C2
Volume 7 (1980) p. 198, or Journal of
Polymer Science, Polymer Chemistry Edition (Journal of Polymer S
science: Polymer Chemistry
Edition 22 (1984), page 159.

That is, in a high-purity inert atmosphere from which oxygen and water have been removed, for example, in a high-purity argon gas atmosphere, the dihalosilane monomer represented by the following general formula (4) or the following general formula ( It is obtained by bringing a mixture of the dihalosilane monomers represented by 4) and (5) into contact with an alkali metal in an inert solvent to cause polycondensation reaction.

[0044]

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[In the formula, X represents a halogen atom, and R ₁ ,
R ₂ , Ar ₁ and Ar ₂ have the same meanings as described above. ]

[0046]

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[In the formula, X represents a halogen atom, and R ₃ and R ₄ have the same meanings as described above. ]

Here, examples of the halogen element of the dihalosilane monomer include bromine and iodine atoms in addition to the most common chlorine. Further, as the alkali metal, lithium, sodium, potassium and alloys containing them are used, and these alkali metals are used in the reaction in a molten state or in a state of being dispersed in fine particles.

Further, the inert solvent may be any solvent which can dissolve the dihalosilane monomer and is inert to the sodium metal and the dihalosilane monomer, and examples thereof include aromatic solvents such as toluene, xylene and benzene. Hydrocarbons, aliphatic hydrocarbons such as dodecane, heptane, hexane and cyclohexane, and ether solvents such as diethyl ether, tetrahydrofuran and diethylene glycol dimethyl ether tetrahydropyran can be used.

The condensation reaction can be carried out at a temperature between room temperature and the boiling point of the solvent, preferably 60 ° C. to 100 ° C., or the lower temperature of the boiling point of the solvent, and the reaction time is not particularly limited and is, for example, 15 The range from minutes to 24 hours is preferred.

Dihalosilane monomers having various substituents which can be subjected to the Kipping method can be synthesized based on a known synthesis method. That is, it can be obtained by a Grignard reagent of an organic compound such as alkyltrichlorosilane or tetrachlorosilane produced industrially by a so-called direct method, a metathesis reaction using a lithium salt, or a hydrosilylation reaction of hydrosilane with an olefin or an acetylene compound.

Regarding the structure of the organic EL device of the present invention,
Between the electrodes consisting of a pair of anode and cathode, at least one of which is transparent or semi-transparent, if the hole-transporting material and the light-emitting material used in the polysilane compound described above are included, there is no particular limitation, and the structure is Known ones can be adopted, and various modifications can be made without departing from the gist of the present invention.

The laminated structure is, for example, (1) electrode (anode) / hole transport layer / light emitting layer / electrode (cathode) (2) electrode (anode) / hole transport layer / light emitting layer / electron transport layer / Electrode (cathode) (3) Electrode (anode) / (mixed layer of hole transport material and light emitting material) / electrode (cathode) (4) Electrode (anode) / (hole transport material, light emitting material and electron transport material) Examples include mixed layers) / electrodes (cathodes). (1) is called a two-layer structure, and (2) is called a three-layer structure. The organic EL element of the present invention is basically based on these laminated structures, but as described above, it may have a structure in which (1) to (4) other than these are combined, or a plurality of respective layers. The shape, size, material, manufacturing method and the like of the organic EL element of the present invention having these laminated structures are appropriately selected according to the application of the organic EL element, etc., and there is no particular limitation.

The light emitting material used in the organic EL device of the present invention is not particularly limited, and various materials can be applied. A low molecular weight fluorescent substance and a polymeric fluorescent substance are preferable, and a polymeric fluorescent substance is more preferable.

For example, the low molecular weight organic compound is not particularly limited, but naphthalene and its derivative, anthracene and its derivative, perylene and its derivative, polymethine type, xanthene type, coumarin type, cyanine type and the like dyes, 8 -A metal complex of hydroxyquinoline and its derivative, aromatic amine, tetraphenylcyclopentadiene and its derivative, tetraphenylbutadiene and its derivative, etc. can be used. Specifically, for example, JP-A-57-51781 and JP-A-59-51781.
Known materials such as those described in Japanese Patent No. 194393 can be used.

The polymer organic compound which can be used as the light emitting material is not particularly limited, but polyphenylene vinylene, polyarylene, polyalkylthiophene, polyalkylfluorene and the like can be mentioned. The polymeric fluorescent substance used as the light emitting material of the organic EL device of the present invention will be described below.

The polymeric fluorescent substance is a polymer containing the repeating unit represented by the general formula (3) in an amount of 50 mol% or more of all repeating units. Depending on the structure of the repeating unit, the repeating unit represented by the general formula (3) is 70% of all repeating units.
% Or more is more preferable. The polymeric fluorescent substance is
As the repeating unit other than the repeating unit represented by the general formula (3), a divalent aromatic compound group or a derivative thereof, 2
It may contain a valent heterocyclic compound group or a derivative thereof, and a group obtained by combining them. Also,
The repeating unit represented by the general formula (3) or another repeating unit may be linked with a non-conjugated unit having an ether group, an ester group, an amide group, an imide group, or the like, and the repeating unit may be a non-conjugated unit thereof. A conjugated portion may be included.

In the polymeric fluorescent substance of the present invention, Ar ₃ in the general formula (3) is an arylene group or a heterocyclic compound group having 4 to 20 carbon atoms involved in a conjugated bond, Examples thereof include a divalent aromatic compound group or a derivative group thereof shown in 10, a divalent heterocyclic compound group or a derivative group thereof, and a group obtained by combining them.

[0059]

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[R _{8 to} R ₉₉ are each independently hydrogen,
It is a group selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group, and an alkylthio group; an aryl group having 6 to 18 carbon atoms and an aryloxy group; and a heterocyclic compound group having 4 to 14 carbon atoms. ]

Among these, phenylene group, substituted phenylene group, biphenylene group, substituted biphenylene group, naphthalenediyl group, substituted naphthalenediyl group, anthracene-9,10-diyl group, substituted anthracene-9,10
-Diyl, pyridine-2,5-diyl, substituted pyridine-2,5-diyl, thienylene or substituted thienylene are preferred. More preferably, a phenylene group,
Biphenylene group, naphthalenediyl group, pyridine-2,
A 5-diyl group and a thienylene group.

R in the general formula (3)_Five, R₆Is hydrogen or hydrogen
The case of a substituent other than an ano group is carbon.
The alkyl group of the numbers 1 to 20 includes a methyl group and an ethyl group.
Group, n-propyl group, isopropyl group, n-butyl group,
sec-butyl group, tert-butyl group, pentyl group,
Hexyl group, heptyl group, octyl group, decyl group, laur
Examples include ryl group, methyl group, ethyl group, pentyl
A group, a hexyl group, a heptyl group and an octyl group are preferred.
As the aryl group, a phenyl group, 4-C₁~ C ₁₂Al
Coxyphenyl group (C₁~ C₁₂Has 1 to 12 carbon atoms
Indicates that The following description also applies to this. ), 4-C
₁~ C₁₂Alkylphenyl group, 1-naphthyl group, 2-na
Examples include futyl groups.

From the viewpoint of solubility in a solvent, Ar _{3 in the} general formula (3) represents one or more alkyl groups having 4 to 20 carbon atoms, alkoxy groups or alkylthio groups, aryl groups having 6 to 18 carbon atoms or aryloxy groups. Group or carbon number 4 to
It preferably has a group selected from 14 heterocyclic compound groups.

Examples of these substituents are as follows. Examples of the alkyl group having 4 to 20 carbon atoms include n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group and lauryl group, and pentyl group. , Hexyl group, heptyl group and octyl group are preferred.

Examples of the alkoxy group having 4 to 20 carbon atoms include butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, lauryloxy group, pentyloxy group, Hexyloxy group, heptyloxy group and octyloxy group are preferred.

As the alkylthio group, a butylthio group,
Examples thereof include a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, a decyloxy group and a laurylthio group, and a pentylthio group, a hexylthio group, a heptylthio group and an octylthio group are preferable.

Examples of the aryl group include phenyl group and 4-C
₁~ C₁₂Alkoxyphenyl group (C ₁~ C₁₂Has carbon number
Indicates that the number is any one of 1 to 12. ), 4-C
₁~ C₁₂Alkylphenyl group, 1-naphthyl group, 2-na
Examples include futyl groups.

Examples of the aryloxy group include a phenoxy group. Examples of the heterocyclic compound group include 2-thienyl group, 2-pyrrolyl group, 2-furyl group, 2-, 3- or 4-pyridyl group.

The number of these substituents varies depending on the molecular weight of the polymeric fluorescent substance and the constitution of the repeating unit, but from the viewpoint of obtaining a highly soluble polymeric fluorescent substance, one of these substituents is present per 600 molecular weight. The above is more preferable.

The polymeric fluorescent substance used in the organic EL device of the present invention may be a random, block or graft copolymer, or a polymer having an intermediate structure between them, such as a block type polymer. It may be a random copolymer. From the viewpoint of obtaining a polymeric fluorescent substance having a high quantum yield of fluorescence, a random copolymer having block properties or a block or graft copolymer is preferable to a complete random copolymer. Further, since the organic EL element of the present invention utilizes light emission from a thin film, the polymeric fluorescent substance used is one having fluorescence in a solid state.

As a good solvent for the polymeric fluorescent substance,
Examples include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene and the like.
Although it depends on the structure and molecular weight of the polymeric fluorescent substance, it can be usually dissolved in these solvents in an amount of 0.1% by weight or more.

The polymeric fluorescent substance using the organic EL device of the present invention preferably has a molecular weight of 10 ³ to 10 ⁷ in terms of polystyrene, and the degree of polymerization thereof varies depending on the repeating structure and the ratio thereof. From the viewpoint of film-forming property, generally, the total number of repeating structures is preferably 4 to 10000, more preferably 5 to 3000, and particularly preferably 10 to 200.
0.

In the organic EL device of the present invention, it is used in an electron transporting layer when an electron transporting layer is further provided between a layer containing a light emitting material and a cathode, or is mixed with a hole transporting material and a light emitting material. The electron transporting material has a function of transmitting the electrons injected from the cathode to the light emitting material.
There is no particular limitation on such an electron-transporting material, and any one of conventionally known compounds can be selected and used.

Preferred examples of the electron transporting material include:
Examples thereof include nitro-substituted fluorenone derivatives, anthraquinodimethane derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic acid anhydrides, and carbodiimides.

Further, a fluorenylidene methane derivative,
Anthraquinodimethane derivative and anthrone derivative,
An oxadiazole derivative etc. can be mentioned. Although disclosed as a material for forming a light emitting layer,
-A metal complex of hydroxyquinoline and its derivative and the like can also be used as the electron transport material.

Next, a typical method for producing an organic EL element having a laminated structure, which is an example of the present invention, will be described. As a pair of transparent and semitransparent electrodes composed of an anode and a cathode, for example, a transparent or semitransparent electrode formed on a transparent substrate such as transparent glass or transparent plastic is used.

As the material of the anode, for example, a conductive metal oxide film, a semitransparent metal thin film or the like is used. Specifically, a film (NE) formed using conductive glass made of indium, tin, oxide (ITO), tin oxide, or the like.
SA, etc.), Au, Pt, Ag, Cu, etc. are used.
Examples of the manufacturing method include a vacuum vapor deposition method, a sputtering method, a plating method and the like.

A hole transport layer containing the polysilane compound is formed on this anode. As a forming method, 1 to 30% by weight of the polysilane compound in a solvent is dissolved in a solvent to prepare a coating solution, and the coating solution is used to spin coating, casting, dipping or bar coating. Examples of the method include coating by a roll coating method or the like. A well-known hole-transporting material may be used in combination in the hole-transporting layer as long as the characteristics of the polysilane compound of the present invention are not impaired. Further, the second hole transport layer may be used adjacent to the hole transport layer containing the polysilane compound.

Examples of the organic solvent used in the solution include aromatic solvents such as benzene, toluene and xylene,
Examples include ether solvents such as diethyl ether and tetrahydrofuran, and halogen solvents such as chloroform.

The thickness of the hole transport layer is preferably 1 nm to
It is 1 μm, more preferably 2 to 500 nm. The range of 5 to 100 nm is more preferable in order to increase the current density and luminous efficiency.

Next, a light emitting layer containing a low molecular weight organic dye, a polymeric fluorescent substance or the like as a light emitting material is formed. Examples of the method for forming the light emitting layer include a method of applying a melt, a solution or a mixed solution of these materials by a spin coating method, a casting method, a dipping method, a bar coating method, a roll coating method or the like. The solution or the mixed solution is preferably formed into a film by a coating method such as a spin coating method, a casting method, a dipping method, a bar coating method or a roll coating method.

The thickness of the light emitting layer is preferably 1 nm to 1 μm.
m, more preferably 2 to 500 nm. The range of 5 to 100 nm is more preferable in order to increase the current density and luminous efficiency.

When the hole transport layer and / or the light emitting layer is formed into a thin film by a coating method, the solvent is removed. Therefore, after forming the hole transport layer and / or after forming the light emitting layer,
It is desirable to heat and dry under reduced pressure or in an inert atmosphere at a temperature of 30 to 300 ° C, preferably 60 to 200 ° C.

When an electron transport layer is further laminated on the light emitting layer, it is preferable to form the electron transport layer on the light emitting layer after the light emitting layer is provided by the above-mentioned film forming method.

The method for forming the electron transport layer is not particularly limited, but it is a vacuum deposition method from a powder state, or a spin coating method after casting in a solution, a casting method, a dipping method, a bar coating method, a roll coating method. Or a coating method such as a spin coating method, a casting method, a dipping method, a bar coating method or a roll coating method after mixing and dispersing a polymer compound and an electron transport material in a solution state or a molten state Can be used.

The polymer compound to be mixed is not particularly limited, but those which do not extremely disturb electron transport are preferable, and those which do not have strong absorption of visible light are suitably used.

For example, poly (N-vinylcarbazole)
And its derivatives, polyaniline and its derivatives, polythiophene and its derivatives, poly (p-phenylene vinylene) and its derivatives, poly (2,5-thienylene vinylene) and its derivatives, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl Examples thereof include methacrylate, polystyrene, polyvinyl chloride, polysiloxane and the like. From the viewpoint of easy film formation, it is preferable to use a coating method when a polymer compound is used.

The film thickness of the electron transport layer needs to be at least such that pinholes are not generated, but if it is too thick, the resistance of the device increases and a high driving voltage is required, which is not preferable. Therefore, the thickness of the charge transport layer is preferably 1 nm to 1 μm, more preferably 2 to 500 nm,
More preferably, it is 5 to 100 nm.

Next, an electrode is provided on the light emitting layer or the electron transporting layer. This electrode becomes an electron injection cathode. The material is not particularly limited, but a material having a low work function is preferable.

For example, Al, In, Mg, Ca, Li,
Mg-Ag alloy, In-Ag alloy, Mg-In alloy, M
A g-Al alloy, a Mg-Li alloy, an Al-Li alloy, a graphite thin film or the like is used. As a method for manufacturing the cathode, a vacuum evaporation method, a sputtering method, or the like is used.

In the organic EL device of the present invention, an organic layer containing a hole-transporting material and a light-emitting material, or an organic layer containing a hole-transporting material, a light-emitting material and an electron-transporting material is the same as the above-mentioned hole-transporting layer. A method of forming on one electrode by any method and then forming another electrode is also exemplified.

Since the organic EL device of the present invention uses a polysilane compound having a high hole drift mobility as a hole transport material, it exhibits characteristics of higher brightness and higher luminous efficiency at a lower driving voltage, and is applied by a coating method. Since the hole transport layer and the light emitting layer can be formed by the method, they can be easily manufactured by a simple manufacturing process.

[0093]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following examples, the molecular weight of the polymer is determined by gel permeation chromatograph (Waters, Maxima-82).
0, Column Ultrastyragel Linea
r: mobile phase tetrahydrofuran) was used to measure the polystyrene-reduced number average molecular weight and weight average molecular weight. Structural analysis was performed using ¹ H, ¹³ C-NMR (Bruker model AC200P). The hole drift mobility was measured by a known method such as the standard time of flight method (Joseph Mort.
And D. Pai edition, Photoconductivit
y and Related Phenomena (N
ew York, 1976) 27-69).

Synthesis Example 1 Synthesis of ethyl (N, N-diphenylaminophenyl) dichlorosilane Unless otherwise specified below, the reaction is performed under a dry argon atmosphere based on the method known as the Schlenk method. To do. In a 100 ml two-necked flask which was dried at 200 ° C., assembled while still hot, cooled while being evacuated, and filled with dry argon, 4.7 g of (4-
N, N-diphenylamino) bromobenzene was loaded,
Melt dried under vacuum. To this was added 20 ml of dry tetrahydrofuran that had just been distilled over sodium using a gas tight syringe (4-N, N-diphenylamino).
After dissolving bromobenzene, n-butyllithium (Aldrich 1.6N hexane solution) was added at -78 ° C.
9.4 ml was added dropwise and reacted for 1 hour to produce (4-N, N-diphenylamino) phenyllithium.

Similarly, a dried 100 ml two-necked flask was charged with 3.4 g of ethyltrichlorosilane (LS-120, manufactured by Shin-Etsu Chemical Co., Ltd.) distilled on calcium hydride immediately before and 15 ml of dry tetrahydrofuran, and cooled to -78 ° C. Then, the above-mentioned (4-N, N-diphenylamino) phenyllithium was dropped using a cannula. After dripping,
After performing the reaction overnight, excess ethyltrichlorosilane and the solvent were distilled off, and the residue was distilled using Kugelrohr to obtain 2.8 g of ethyl (N, N-diphenylaminophenyl) dichlorosilane. Yield was 45%.

Structural analysis data (NMR) ¹ H-NMR 0.97 to 1.06 ppm (3H) CH ₃ CH ₂ —Si 1.12 to 1.25 ppm (2H) CH ₃ CH ₂ —Si 6.90 to 7 .40ppm (12 _{present: 14H) (C 6 H 5} ) 2 N (C 6 H 4) -Si ( dioxane 3.57ppm _{^{reference) 13 C-NMR 6.4ppm CH 3}} CH 2 -Si 13.3ppm CH 3 CH ₂ -Si _121~151ppm (8 _{present) (C 6 H 5) 2} N (C 6 H 4) -Si ( deuterochloroform 77.1ppm reference)

Synthesis Example 2 Synthesis and Evaluation of Polysilane Compound A 50 ml three-necked flask dried at 200 ° C. was loaded with a rubber septum and an argon seal, and cooled while repeating evacuation and filling with dry argon. The flask was charged with 0.7 g of metallic sodium in a dry nitrogen atmosphere, and 16 ml of toluene which had been dried over sodium and distilled just before was added. This flask was set in an ultrasonic disperser (Branson Model 450) under a dry argon flow,
Ultrasonic waves were radiated while heating to 0 ° C. to 105 ° C. to disperse sodium in an average particle size of 50 μm. After the dispersion, the flask was left standing and 12 ml of excess toluene in the supernatant was removed with a syringe.

Similarly, a dried 50 ml three-necked flask was equipped with a magnetic stirrer, a thermocouple and a rubber septum, and 4.9 g of ethyl (N, N-diphenylaminophenyl) dichlorosilane synthesized in the same manner as in Synthesis Example 1. And 4 ml of dry toluene were added to form a solution. After the temperature of this flask was raised to 80 ° C., the sodium dispersion liquid was added dropwise using a Teflon cannula over about 10 minutes. The temperature inside the flask was temporarily raised to 120 ° C. by the dropping. After the start of dropping, the reaction was carried out for 4 hours.

After completion of the reaction, 20 ml of toluene and 3 ml of isopropyl alcohol were added to the flask under argon flow to deactivate excess metallic sodium, and further about 10 ml of distilled water was added to dissolve the purple precipitate. The precipitate was separated by centrifugation and washed twice with toluene to recover the soluble matter as a toluene solution. The toluene solution was washed with water and dried over anhydrous magnesium sulfate, and then the solvent was distilled off to obtain a glassy substance. This glassy substance was made into a tetrahydrofuran solution, reprecipitated with isopropyl alcohol and repeated purification to obtain 0.24 g of a polymer. As a result of measuring the molecular weight distribution of the polymer using GPC, it was confirmed that a high molecular weight polysilane compound was obtained. The results of NMR and elemental analysis corresponded to poly (ethyl (4- (N, N-diphenylamino) phenyl) silane).

Structural analysis data (NMR) ¹ H-NMR −0.6 to 0.6 ppm (5H) CH ₃ CH ₂ —Si 6.6 to 7.2 ppm (14H) (C ₆ H ₅ ) ₂ N (C ₆ H ₄ ) -Si

Elemental analysis (% by weight) Si C H N Measured value 8.2 80.0 6.4 4.7 Predicted value 9.3 80.0 6.4 4.6

Molecular weight Weight average molecular weight = 1.1 × 10 ⁶ Number average molecular weight = 7.3 × 10 ³

Evaluation of Hole Drift Mobility 0.1 g of the polysilane compound synthesized as described above was dissolved in 1.9 g of dehydrated toluene to obtain a 5 wt% toluene solution. This toluene solution was filtered through a 0.2 μm membrane filter to obtain a coating solution. Using this coating solution, a glass substrate on which a transparent conductive film (ITO) is deposited is spin-coated on a charge generation layer formed by vacuum-depositing metal selenium to a thickness of 0.2 μm. To a film thickness of 5.8 μm to form a polysilane hole transport layer. Further, a gold electrode was vapor-deposited on the polysilane hole transport layer by a vacuum vapor deposition method to obtain a sample for measuring hole drift mobility by the time of flight method.

A nitrogen laser-excited dye laser (manufactured by Laser Photonics, nitrogen laser-excited dye laser, model LN1000 / LN) was attached to this sample from the transparent electrode side.
102) using flash light (wavelength: 481 nm,
The flash drift time: 1 nsec) was applied, and the hole drift mobility was measured by the usual time of flight method. For photocurrent measurements, Hewlett-Packard Digitizing Oscilloscope, Model 54710A / 547.
13A was used. As a result, a hole drift mobility of 3 × 10 ⁻³ cm ² / Vsec was obtained at room temperature (25 ° C.) and an applied voltage of 290 V (electric field strength: 0.5 MV / cm).

Example 1 Preparation and Evaluation of Organic EL Device A 2 wt% toluene solution of the polysilane compound synthesized in Synthesis Example 2 was spun on a glass substrate having an ITO film with a thickness of 40 nm by a sputtering method. A film having a thickness of 80 nm was formed by a coating method to form a hole transport layer. Next, this was dried under reduced pressure at 120 ° C. for 1 hour, and then 50 nm of tris (8-quinolinol) aluminum (Alq ₃ ) was vapor-deposited as a light emitting layer on the hole transport layer. Finally, an aluminum-lithium alloy (Al: Li = 99: 1 weight ratio) 20 is formed on the light emitting layer as a cathode.
A 2-layer organic EL device of the present invention was produced by vapor deposition with a thickness of 0 nm. The degree of vacuum during vapor deposition is 8 × 10 ^-6 Tor
r or less.

When a voltage of 18 V was applied to this organic EL device, a current with a current density of 50 mA / cm ² flowed, and yellow-green EL light emission with a luminance of 1310 cd / m ² was observed.
The luminous efficiency at this time was 2.6 cd / A. Also,
The EL peak wavelength was 520 nm, which was almost the same as the fluorescence peak wavelength of the Alq ₃ thin film.

Example 2 Preparation and Evaluation of Organic EL Device In the same manner as in Example 1, a 2% by weight toluene solution of the polysilane compound synthesized in Synthesis Example 2 was spin-coated on a glass substrate provided with an ITO film. 80 by coating method
The film was formed with a thickness of nm. Next, this was dried under reduced pressure at 120 ° C. for 1 hour, and then tris (8-quinolinol) aluminum (Alq ₃ ) powder was deposited by 50 nm as a light emitting layer. Then, as an electron transport layer on the light emitting layer,
50 nm of 2,5-diphenyl-1,3,4-oxadiazole (PBD) powder was deposited. Finally, 200 nm of aluminum-lithium alloy (Al: Li = 99: 1 weight ratio) was vapor-deposited as a cathode on the electron transport layer to prepare an organic EL device having a three-layer structure of the present invention. The degree of vacuum at the time of vapor deposition was 8 × 10 ⁻⁶ Torr or less.

When a voltage of 18 V was applied to this organic EL device, a current having a current density of 39 mA / cm ² flowed, and yellowish green EL light emission with a brightness of 1750 cd / m ² was observed.
The luminous efficiency at this time was 4.4 cd / A. Also,
The EL peak wavelength was 520 nm, which was almost the same as the fluorescence peak wavelength of the Alq ₃ thin film.

Synthesis Example 3 In a 100 ml three-necked flask dried in the same manner as in Synthesis Example 2, 1.3 g of sodium was placed, and 19 ml of dry toluene was added.
Was added. 4. This flask was irradiated with ultrasonic waves under a dry argon flow to disperse sodium to an average particle size of 50 μm or less, heated to 62 ° C., and distilled immediately before methylphenyldichlorosilane (Shin-Etsu Chemical LS-1490). 0 g
Was dropped using a gas tight syringe for about 20 minutes. After the dropping, the temperature in the flask is temporarily 11 due to the heat of reaction.
The temperature rose to 0 ° C. and reflux of the solvent was observed. Upon completion of dropping, the temperature of the flask was raised to 85 ° C., and the reaction was further performed for 40 minutes. After the reaction was completed, the polymer was purified in the same manner as in Synthesis Example 2 to obtain 0.8 g of polymethylphenylsilane.

Structural analysis data (NMR) ¹ H-NMR -1.2 to 0.3 ppm (3H) CH ₃ -Si 6.0 to 7.4 ppm (5H) C ₆ H ₅ -Si

Elemental analysis (% by weight) SiCH 2 N 2 Measured value 22.0 69.0 6.9 <0.3 Expected value 23.0 70.0 6.7 0

Molecular weight Weight average molecular weight = 2.3 × 10 ⁵ Number average molecular weight = 6.2 × 10 ³

Evaluation of Hole Drift Mobility Using the polysilane compound synthesized in Synthesis Example 3 and in the same manner as in Synthesis Example 2, a sample for measuring hole drift mobility by a time-of-flight method with a film thickness of 4.0 μm. At room temperature (25 ° C) and applied voltage of 200V (electric field strength: 0.5M
V / cm) and the hole drift mobility is 2
× 10 ⁻⁴ cm ² / Vsec was obtained.

Comparative Example 1 Preparation and Evaluation of Organic EL Device The polysilane compound synthesized in Synthesis Example 3 was used in place of the polysilane compound synthesized in Synthesis Example 2, and the organic compound having a two-layer structure was prepared in the same manner as in Example 1. An EL device was produced. When a voltage of 20 V was applied to the obtained organic EL element, a current with a current density of 14 mA / cm ² was flowed, and a luminance of 340 cd /
A yellow-green EL emission of m ² was observed. The luminous efficiency at this time was 2.4 cd / A. The EL peak wavelength was 520 nm, which was almost the same as the fluorescence peak wavelength of the Alq ₃ thin film.

Comparative Example 2 Preparation and Evaluation of Organic EL Device The polysilane compound synthesized in Synthesis Example 3 was used in place of the polysilane compound synthesized in Synthesis Example 2, and the organic compound having the three-layer structure was prepared in the same manner as in Example 2. An EL device was produced. When a voltage of 20 V was applied to the obtained organic EL element, a current with a current density of 16 mA / cm ² flowed and the luminance of 620 cd /
A yellow-green EL emission of m ² was observed. The luminous efficiency at this time was 3.9 cd / A. The EL peak wavelength was 520 nm, which was almost the same as the fluorescence peak wavelength of the Alq ₃ thin film.

Synthesis Example 4 Synthesis of polymeric fluorescent substance 2,5-dioctyloxy-p-xylylenedibromide was reacted with triphenylphosphine in a N, N-dimethylformamide solvent to synthesize a phosphonium salt. 47.75 parts by weight of the obtained phosphonium salt and 6.7 parts by weight of terephthalaldehyde were dissolved in ethyl alcohol. An ethyl alcohol solution containing 5.8 parts by weight of lithium ethoxide was added dropwise to an ethyl alcohol solution of a phosphonium salt and dialdehyde, and polymerized at room temperature for 3 hours. After standing overnight at room temperature, the precipitate was filtered off, washed with ethyl alcohol, dissolved in chloroform, and ethanol was added to this to reprecipitate. This was dried under reduced pressure to obtain 8.0 parts by weight of a polymer. This is called polymeric fluorescent substance 1. The repeating units of polymeric fluorescent substance 1 calculated from the charged ratio of the monomers and the molar ratios thereof are shown below.

[0117]

Embedded image

The molar ratio of the two repeating units is 1: 1 and the two repeating units are linked alternately. The polystyrene-reduced number average molecular weight of the polymeric fluorescent substance 1 is
It was 1.0 × 10 ⁴ . The structure of the polymeric fluorescent substance 1 was confirmed by infrared absorption spectrum and NMR.

Example 3 On a glass substrate having an ITO film with a thickness of 40 nm attached by sputtering, 0.9% by weight of the polysilane compound obtained in Synthesis Example 1 and 2 of the polymer light-emitting body 1 obtained in Synthesis Example 4 were used. ．
A toluene solution containing 1% by weight was used to form a film with a thickness of 140 nm by spin coating. Then, tris (8-quinolinol) aluminum (Alq ₃ ) was deposited to a thickness of 40 nm as an electron transport layer. An aluminum-lithium alloy (lithium concentration: 1% by weight) was vapor-deposited thereon to a thickness of 130 nm as a cathode to produce an organic EL device. The degree of vacuum at the time of vapor deposition was 8 × 10 ⁻⁶ Torr or less.

When a voltage of 10 V was applied to this element,
A current with a current density of 230 mA / cm ² flows and the brightness is 262.
An EL emission of 6 cd / m ² was observed. The luminous efficiency at this time was 1.2 cd / A. The brightness was almost proportional to the current density. Also, the EL peak wavelength is 545 nm
As a result, the fluorescence peak wavelength of the thin film of the polymeric fluorescent substance 1 was almost the same, and EL emission from the polymeric fluorescent substance 1 was confirmed.

Example 4 Preparation and Evaluation of Organic EL Device Spin on a glass substrate having an ITO film with a thickness of 40 nm by sputtering, using a 1.5 wt% toluene solution of the polysilane compound synthesized in Synthesis Example 2. A hole transport layer having a thickness of 120 nm was formed by the coating method. Furthermore, 1.0 of the polymeric fluorescent substance 1 obtained in Synthesis Example 4 was used.
A light emitting layer having a thickness of 40 nm was formed by a spin coating method using a wt% toluene solution. Next, after drying this under reduced pressure at 120 ° C. for 1 hour, an electron transport layer was formed.
Tris (8-quinolinol) aluminum (Alq ₃₎
The powder was evaporated to 40 nm. Finally, an aluminum-lithium alloy (Al: Li
= 99: 1 weight ratio) was vapor-deposited at 110 nm to prepare an organic EL device having a three-layer structure. The degree of vacuum during vapor deposition is 8
It was not more than × 10 ⁶ Torr.

When a voltage of 8 V was applied to this element, a current with a current density of 54 mA / cm ² flowed, and the luminance 1320c
Yellow-green EL emission of d / m ² was observed. The luminous efficiency at this time was 2.4 cd / A. The brightness was almost proportional to the current density. The EL peak wavelength is 545n
At m, it was almost coincident with the fluorescence peak wavelength of the thin film of polymeric fluorescent substance 1, and EL emission from polymeric fluorescent substance 1 was confirmed.

[0123]

EFFECT OF THE INVENTION The organic EL of the present invention using a polysilane compound having a high hole drift mobility as a hole transport material.
Since the device is easy to manufacture and has a high current transport capability, it exhibits excellent characteristics of lower driving voltage, higher brightness and higher luminous efficiency, and is a device such as a planar light source as a backlight or a flat panel display. Can be preferably used as

Claims (7)

[Claims] 1. At least one organic layer is provided between a pair of electrodes, at least one of which is transparent or semitransparent,
In an organic electroluminescence device in which the organic layer contains a hole transport material and a light emitting material in the same layer or different layers, the hole transport material has a main chain skeleton represented by the following general formula (1): [In the formula, R ₁ and R ₂ each independently represent an optionally substituted alkyl group, cycloalkyl group, aryl group or aralkyl group. Ar ₁ represents an optionally substituted arylene group, and Ar ₂ represents an optionally substituted aryl group. ] The repeating structural unit represented by the following general formula (2) [In the formula, R ₃ and R ₄ each independently represent an optionally substituted alkyl group, cycloalkyl group, aryl group or aralkyl group. ] And the repeating structural units (1) and (2)
When the ratios of the number of repeating structural units (1) and (2) to the total number of units of are respectively z and 1-z, 0.2 ≦ z ≦ 1 and the weight average molecular weight is 5000.
And above, and the hole drift mobility is 10 ⁻³ to 10 ^−1.
An organic electroluminescent device comprising a hole transport material containing a polysilane compound having a cm ² / Vsec. 2. In the general formula (1), R ₂ is an optionally substituted phenyl group, Ar ₁ is an optionally substituted phenylene group, and Ar ₂ is an optionally substituted phenyl group. Item 2. The organic electroluminescence device according to item 1. 3. At least one organic layer is provided between a pair of electrodes, at least one of which is transparent or semitransparent,
In the organic electroluminescent device, in which the organic layer contains a hole transport material and a light emitting material in the same layer or another layer, one kind of repeating unit represented by the following formula (3) has fluorescence in the solid state as a light emitting material. And the total number of repeating units is 50 mol% or more of all repeating units, and the polystyrene-equivalent number average molecular weight is 1
^3. The organic electroluminescent device according to claim 1, which contains at least one kind of polymeric fluorescent substance of 0 ³ to 10 ⁷ . Embedded image [Here, Ar ₃ represents an arylene group or a heterocyclic compound group in which the number of carbon atoms involved in a conjugated bond is 4 or more and 20 or less. R ₅ and R ₆ are independently hydrogen,
A group selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heterocyclic compound group having 4 to 20 carbon atoms and a cyano group is shown. ] 4. The organic electroluminescence device according to claim 1, wherein the hole transport layer containing at least one polysilane compound according to claim 1 or 2 and a light emitting layer are laminated. element. 5. A hole transport layer, a light emitting layer, and an electron transport layer containing one or more kinds of polysilane compounds according to claim 1 or 2, which are laminated.
3. The organic electroluminescence device according to 3 or 4. 6. A hole transport material containing one or more polysilane compounds according to claim 1 or 2 and a light emitting material.
The organic electroluminescence device according to claim 1, wherein the organic electroluminescence device comprises at least two organic layers. 7. One or more organic layers containing a hole-transporting material, a light-emitting material and an electron-transporting material containing at least one polysilane compound according to claim 1 or 2. The organic electroluminescent element according to claim 1, 2 or 3.