JP2013219278A - Organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element capable of preventing a reduction in luminous efficiency while suppressing a leakage current in a hole injection layer.SOLUTION: An organic electroluminescent element 10 of the present invention is provided with a light-emitting part 14 between a pair of electrodes. The light-emitting part 14 has a light-emitting layer 14b, a hole injection layer 14a causing holes to move from one electrode to the light-emitting layer 14b, and an electron transport layer 14c causing electrons to move from the other electrode toward the light-emitting layer 14b. The hole injection layer 14a includes a semiconductive polymer film formed from a semiconductive polymer coating, and the semiconductive polymer coating contains a complex of a novolac resin having a bisphenol S unit and a phenol sulfonic acid unit with a polymer of thiophene or its derivative.

Description

  The present invention relates to an organic electroluminescence element.

In recent years, in the field of thin displays, in addition to plasma displays and liquid crystal displays, organic electroluminescent displays including organic electroluminescent elements have been commercialized. Also in the lighting field, in addition to LED lighting using inorganic semiconductors, development of thin flat lighting using organic electroluminescence elements is also underway.
An organic electroluminescence element is a spontaneous emission type light emitting element using a principle that a fluorescent substance emits light by energy generated when holes injected from an anode and electrons injected from a cathode are recombined.
The simplest structure of an organic electroluminescence element is a three-layer structure of a transparent electrode that serves as an anode, a light emitting layer that emits light spontaneously, and a metal electrode that serves as a cathode, but in order to increase luminous efficiency and emit light at a lower voltage, An auxiliary layer is often provided. For example, a hole injection layer may be provided between the anode and the light emitting layer, and an electron injection layer may be provided between the light emitting layer and the cathode.

One reason for providing an auxiliary layer such as a hole injection layer or an electron injection layer is to lower the energy barrier in the injection of holes and electrons injected from each electrode.
That is, an organic light-emitting member typified by tris (8-quinolinolato) aluminum (hereinafter referred to as “Alq3”) has an energy level of its highest occupied orbit (HOMO) of 6 eV and a lowest empty orbit (LUMO). Many have energy levels in the vicinity of 3 eV. On the other hand, the work function of the transparent electrode and indium tin oxide (ITO) used for the anode is 4.5 to 5 eV, and the work function of the aluminum electrode used for the cathode is 4 to 4.5 eV. Therefore, an energy barrier of 1 eV exists in each of the anode and the cathode, and when an organic electroluminescence element is configured with an anode / light emitting layer / cathode structure, the light emission potential becomes high and the light emission efficiency becomes low.
Therefore, by providing an auxiliary layer that reduces the inclination of each energy barrier, the light emission efficiency of the organic electroluminescence element is improved. Usually, a hole injection layer made of a material having a HOMO level energy of about 5 to 6 eV is provided between the anode and the light emitting layer, and LUMO is formed between the light emitting layer and the cathode in the case of organic materials and in the case of inorganic materials. An electron injection layer made of a material having a work function of about 3 to 4 eV is provided.
Thus, the energy level of the auxiliary layer is important for the light emission efficiency of the organic electroluminescence element.

In addition, the hole injection layer is required to have a sufficiently large specific resistance value. When the specific resistance value of the hole injection layer is low, the leakage current flowing outside the predetermined light emitting circuit increases, and weak light emission is likely to occur at a place other than the predetermined light emitting portion. Since this weak light emission is often seen in the vicinity of the light emitting part, the outline of the light emitting part tends to be blurred, which becomes a big problem in display applications where the contrast between adjacent light emitting parts is a problem. Further, since the leakage current is converted as thermal energy, it causes a reduction in the lifetime of the element. It is said that a specific resistance value of 10 ⁴ Ωcm or more is necessary to sufficiently suppress the leakage current.

PEDOT / PSS in which poly (3,4-ethylenedioxythiophene) is doped with polystyrene sulfonic acid is a p-type organic semiconductor that plays a role in electrical conduction, and has a HOMO level energy of about 5.2 eV. Thus, it is positioned between ITO as the anode and Alq3 as the light emitting layer. Therefore, utilization as a hole injection layer is examined (patent document 1).
Further, since PEDOT / PSS is provided as a dispersion, a layer can be formed by coating. Therefore, when forming a hole injection layer using PEDOT / PSS, it is possible to form a film only by a wet process without requiring a vapor deposition process. I can respond.

In PEDOT / PSS, if the mass ratio of PSS to PEDOT is increased, the resistance can be increased. Therefore, in the PEDOT / PSS for the hole injection layer, the blending amount of PSS is increased in order to increase the specific resistance value and reduce the leakage current. Specifically, the mass ratio of PEDOT / PSS Is about 1: 6 to 1:20.
However, there is a limit to increasing the resistance by increasing the PSS, and when the PSS exceeds a certain ratio, the resistance hardly increases even if the PSS is increased. The specific resistance value at that time was about 10 ³ Ωcm, and it was difficult to sufficiently prevent the leakage current at this level.
Therefore, PEDOT / PSS may contain a non-conductive binder resin such as an acrylic resin or an epoxy resin to increase the resistance by inhibiting the conductive path (Patent Document 2).

  However, since the HOMO energy level of a non-conductive organic compound such as a binder resin is usually 6 eV or more, the HOMO energy level of a mixture obtained by mixing the non-conductive organic compound and PEDOT / PSS is PEDOT / It shifts to the side where the absolute value is larger than the HOMO energy level unique to PSS, that is, the side away from the work function of ITO. This shift increases the hole injection barrier with the anode ITO, so that the organic electroluminescent device using a mixture of a non-conductive organic compound and PEDOT / PSS for the hole injection layer has a significant decrease in luminous efficiency. In some cases, no light was emitted.

Japanese Patent No. 4191801 Japanese Patent No. 2916098

  An object of this invention is to provide the organic electroluminescent element which can prevent the fall of luminous efficiency, suppressing the leakage current in a positive hole injection layer.

The organic electroluminescent element of the present invention is provided with a light emitting portion between a pair of electrodes, the light emitting portion comprising a light emitting layer, a hole injection layer for moving holes from one electrode toward the light emitting layer, and the other. In the organic electroluminescence device having an electron transfer layer that moves electrons from the electrode toward the light emitting layer, the hole injection layer includes a polymer semiconductor film formed of a polymer semiconductor paint, and the polymer semiconductor The paint contains a composite of a novolak resin having a bisphenol S unit represented by the following general formula (1) and a phenolsulfonic acid unit represented by the following general formula (2) and a polymer of thiophene or a derivative thereof. It is characterized by doing.
(In the formula, X is any one of H, Li, Na, K, NH _(4-Y) R _Y , and Y is an integer from 0 to 4. R is from 1 to C carbon atoms. When Y is 2 or more, which is any alkyl group of 8, they may be the same or different.The hydrogen constituting the aromatic ring of the bisphenol S unit and the phenolsulfonic acid unit is a methyl group or a methoxy group. And may be substituted with a group, and 1 ≦ m <10000 and 1 ≦ n <10000.)

  The organic electroluminescence device of the present invention can prevent a decrease in light emission efficiency while suppressing leakage current in the hole injection layer.

It is a top view which shows one Embodiment of the organic electroluminescent element of this invention. It is I-I 'sectional drawing of FIG.

An embodiment of the organic electroluminescence element (hereinafter referred to as “OEL element”) of the present invention will be described.
FIG. 1 is a plan view of the OEL element of this embodiment, and FIG. 2 is a cross-sectional view taken along the line II ′ in FIG. The OEL element 10 of this embodiment includes a base material 11, an anode 12 and a cathode 13 provided in a strip shape on one surface of the base material 11, and a light emitting unit 14 provided therebetween. The anode 12 and the cathode 13 are arranged so as to be orthogonal at the center in plan view.
In the OEL element 10, when a potential is applied between the anode 12 and the cathode 13, light emission can be visually recognized through the base material 11 at an orthogonal portion between the anode 12 and the cathode 13.

<Light emitting part>
The light emitting unit 14 is a laminate of at least a hole injection layer 14a, a light emitting layer 14b, and an electron injection layer 14c. The hole injection layer 14a is disposed on the anode 12 side, and the electron injection layer 14c is disposed on the cathode 13 side.

(Hole injection layer)
The hole injection layer 14a is a layer that moves holes from the anode 12 toward the light emitting layer 14b. The hole injection layer 14a in the present embodiment is made of a polymer semiconductor film formed from a polymer semiconductor paint.
The polymer semiconductor paint contains (bisphenol S-phenolsulfonic acid) novolak resin and a polymer of thiophene or a derivative thereof (hereinafter, “polymer of thiophene or a derivative thereof” is referred to as “polythiophene”). To do. Since the (bisphenol S-phenolsulfonic acid) novolac resin is coordinated to polythiophene, polythiophene and (bisphenol S-phenolsulfonic acid) form a complex.

[(Bisphenol S-phenolsulfonic acid) novolak resin]
The (bisphenol S-phenolsulfonic acid) novolak resin used in the present invention is a novolak resin having a bisphenol S unit represented by the general formula (1) and a phenolsulfonic acid unit represented by the general formula (2). It is.
In the general formula (1), X is any one of H, Li, Na, K, NH _(4-Y) R _Y (where Y is an integer from 0 to 4). R in NH _(4-Y) R _Y is an alkyl group having 1 to 8 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, octyl group). In the case of an alkyl group having 3 or more carbon atoms, it may be linear or branched. Moreover, when Y is 2 or more, R may be the same or different.
Hydrogen constituting the aromatic ring of the bisphenol S unit and the phenolsulfonic acid unit may be substituted with a methyl group or a methoxy group.
In the general formula (1), 1 ≦ m <10,000, and preferably 10 ≦ m ≦ 1,000. In the general formula (2), 1 ≦ n <10,000, and preferably 10 ≦ n ≦ 1,000. If m and n are each less than the said upper limit, the viscosity of a polymer semiconductor coating material can be suppressed and application | coating becomes easy.

  (Bisphenol S-phenolsulfonic acid) The molar ratio (m / n) of bisphenol S units to phenolsulfonic acid units in the novolak resin is preferably 50/50 to 5/95, more preferably 40/60 to 15/85. If the molar ratio of the bisphenol S unit to the phenol sulfonic acid unit is 50/50 or less, the acid solubility in water is improved, the degree of polymerization of polythiophene can be easily increased, and the conductivity can be further increased. Moreover, if molar ratio (m / n) is 5/95 or more, transparency can be made higher.

The mass average molecular weight of the (bisphenol S-phenolsulfonic acid) novolak resin is preferably 5,000 to 500,000, more preferably 10,000 to 100,000. The mass average molecular weight can be measured by gel permeation chromatography.
When the mass average molecular weight of the (bisphenol S-phenolsulfonic acid) novolak resin is equal to or higher than the lower limit, the conductivity and transparency can be further increased. On the other hand, if the mass average molecular weight of the (bisphenol S-phenolsulfonic acid) novolak resin is equal to or less than the upper limit, the viscosity of the polymer semiconductor coating can be suppressed, and the coating becomes easy.

  The content of (bisphenol S-phenolsulfonic acid) novolak resin is preferably in the range of 0.1 to 10 mol, more preferably in the range of 1 to 7 mol, relative to 1 mol of polythiophene. When the content of (bisphenol S-phenolsulfonic acid) novolak resin is less than 0.1 mol, the doping effect on polythiophene tends to be weakened, and the conductivity may be insufficient. In addition, the dispersibility and solubility in the solvent are reduced, making it difficult to obtain a uniform dispersion. On the other hand, when the content of (bisphenol S-phenolsulfonic acid) novolak resin is more than 10 mol, the content of polythiophene is decreased, and it is difficult to obtain sufficient conductivity.

[Other anions]
In addition to the (bisphenol S-phenolsulfonic acid) novolak resin, an anion capable of doping polythiophene may be used in combination. In this case, an organic acid is preferable from the viewpoint of adjusting the dedoping characteristics from polythiophene and the solvent solubility of the composite, compatibility with other components, dispersibility, heat resistance, and environmental resistance. Examples of organic acids include organic carboxylic acids, phenols, and organic sulfonic acids.
As the organic carboxylic acid, aliphatic, aromatic, cycloaliphatic and the like containing one or more carboxy groups can be used. For example, formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid, maleic acid, fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, nitroacetic acid, And triphenylacetic acid. Examples of phenols include phenols such as cresol, phenol, and xylenol.

  As the organic sulfonic acid, an aliphatic, aromatic, cycloaliphatic or the like containing one or more sulfonic acid groups can be used. Examples of those containing one sulfonic acid group include methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 1-butanesulfonic acid, 1-hexanesulfonic acid, 1-heptanesulfonic acid, and 1-octanesulfonic acid. 1-nonanesulfonic acid, 1-decanesulfonic acid, 1-dodecanesulfonic acid, 1-tetradecanesulfonic acid, 1-pentadecanesulfonic acid, 2-bromoethanesulfonic acid, 3-chloro-2-hydroxypropanesulfonic acid, trifluoro L-methanesulfonic acid, colistin methanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, aminomethanesulfonic acid, 1-amino-2-naphthol-4-sulfonic acid, 2-amino-5-naphthol 7-sulfonic acid, 3-aminopropanesulfonic acid, N-cyclohexyl- -Aminopropanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, octyl Benzenesulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, dipropylbenzene Sulfonic acid, butylbenzenesulfonic acid, 4-aminobenzenesulfonic acid, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, 4-amino-2-chloroto Ene-5-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-amino-5-methoxy-2-methylbenzenesulfonic acid, 2-amino-5-methylbenzene-1-sulfonic acid, 4-amino-2-methylbenzene-1-sulfonic acid, 5-amino-2-methylbenzene-1-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-acetamido-3-chlorobenzenesulfone Acid, 4-chloro-3-nitrobenzenesulfonic acid, p-chlorobenzenesulfonic acid, naphthalenesulfonic acid, methylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid, butylnaphthalenesulfonic acid, pentylnaphthalenesulfonic acid, dimethylnaphthalenesulfonic acid, 4-amino -1-Naphthalenesulfonic acid, 8-chloronaphthalene- Examples thereof include sulfonic acid compounds containing a sulfonic acid group such as 1-sulfonic acid, naphthalenesulfonic acid formalin polycondensate, and melamine sulfonic acid formalin polycondensate.

  Examples of those containing two or more sulfonic acid groups include ethanedisulfonic acid, butanedisulfonic acid, pentanedisulfonic acid, decanedisulfonic acid, m-benzenedisulfonic acid, o-benzenedisulfonic acid, p-benzenedisulfonic acid, and toluenedisulfone. Acid, xylene disulfonic acid, chlorobenzene disulfonic acid, fluorobenzene disulfonic acid, aniline-2,4-disulfonic acid, aniline-2,5-disulfonic acid, dimethylbenzene disulfonic acid, diethylbenzene disulfonic acid, dibutylbenzene sulfonic acid, naphthalene disulfonic acid , Methyl naphthalene disulfonic acid, ethyl naphthalene disulfonic acid, dodecyl naphthalene disulfonic acid, pentadecyl naphthalene disulfonic acid, butyl naphthalene disulfonic acid, 2-amino-1,4-benzene Zendisulfonic acid, 1-amino-3,8-naphthalenedisulfonic acid, 3-amino-1,5-naphthalenedisulfonic acid, 8-amino-1-naphthol-3,6-disulfonic acid, 4-amino-5 -Naphthol-2,7-disulfonic acid, anthracene disulfonic acid, butylanthracene disulfonic acid, 4-acetamido-4'-isothio-cyanatostilbene-2,2'-disulfonic acid, 4-acetamido-4'-isothi Ocyanatostilbene-2,2'-disulfonic acid, 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid, 1-acetoxypyrene-3,6,8-trisulfonic acid, 7-amino -1,3,6-naphthalene trisulfonic acid, 8-aminonaphthalene-1,3,6-trisulfonic acid, 3-amino-1,5,7- Full talent re-sulfonic acid, and the like.

The anion other than this (bisphenol S-phenolsulfonic acid) novolak resin is oxidized with the precursor monomer, (bisphenol S-phenolsulfonic acid) novolak resin, before polymerization of the precursor monomer of polythiophene in the production method described later. You may add to the solution containing an agent and / or an oxidation polymerization catalyst. Moreover, you may add to the dispersion liquid containing a composite_body | complex after superposition | polymerization.
The mass ratio of the precursor monomer to the (bisphenol S-phenolsulfonic acid) novolak resin is preferably precursor monomer: (bisphenol S-phenolsulfonic acid) novolak resin = 1: 20 to 5: 1, preferably 10: 1 to 1. : 1 is more preferable

[Polythiophene]
Specific examples of monomers constituting polythiophene include thiophene, 3-methylthiophene, 3-ethylthiophene, 3-propylthiophene, 3-butylthiophene, 3-hexylthiophene, 3-heptylthiophene, 3-octylthiophene, 3-decylthiophene, 3-dodecylthiophene, 3-octadecylthiophene, 3-bromothiophene, 3-chlorothiophene, 3-iodothiophene, 3-cyanothiophene, 3-phenylthiophene, 3,4-dimethylthiophene, 3,4 -Dibutylthiophene, 3-hydroxythiophene, 3-methoxythiophene, 3-ethoxythiophene, 3-butoxythiophene, 3-hexyloxythiophene, 3-heptyloxythiophene, 3-octyloxythiophene, 3-decyloxy Thiophene, 3-dodecyloxythiophene, 3-octadecyloxythiophene, 3,4-dihydroxythiophene, 3,4-dimethoxythiophene, 3,4-diethoxythiophene, 3,4-dipropoxythiophene, 3,4-dibutoxy Thiophene, 3,4-dihexyloxythiophene, 3,4-diheptyloxythiophene, 3,4-dioctyloxythiophene, 3,4-didecyloxythiophene, 3,4-didodecyloxythiophene, 3,4-ethylene Dioxythiophene, 3,4-propylenedioxythiophene, 3,4-butenedioxythiophene, 3-methyl-4-methoxythiophene, 3-methyl-4-ethoxythiophene, 3-carboxythiophene, 3-methyl-4 -Carboxythiophene, 3-methyl- - carboxyethyl thiophene, and 3-methyl-4-carboxybutyl thiophene. Among these, 3,4-ethylenedioxythiophene is preferable from the viewpoint of conductivity, transparency, and heat resistance.

(thickness)
The thickness of the hole injection layer 14a is preferably 1 nm to 1 μm, and more preferably 10 to 500 nm.

(Polymer semiconductor paint)
The polymer semiconductor paint that forms the polymer semiconductor film is a dispersion liquid in which the composite is dispersed in at least one of water and an organic solvent.
In the polymer semiconductor paint, the total content of the composite is preferably 0.05 to 99.5% by mass when the total solid content is 100% by mass, and preferably 0.5 to 99.5% by mass. It is more preferable that When the total content of the composite is less than the lower limit, appropriate conductivity may not be obtained, and when the upper limit is exceeded, a uniform coating film may not be obtained.

[Organic solvent]
Examples of the organic solvent include polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylene phosphortriamide, methanol, ethanol, Alcohols such as propanol, butanol, ethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, isoprene glycol, butanediol, 1,5-pentanediol Polyhydric aliphatic alcohols such as 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, carbonate compounds such as ethylene carbonate and propylene carbonate, cyclic ether compounds such as dioxane and tetrahydrofuran, dialkyl Chain ethers such as ether, ethylene glycol monoalkyl ether, ethylene glycol dialkyl ether, propylene glycol monoalkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, ethyl acetate, propyl acetate, butyl acetate, etc. Ester solvents, diethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisopropyl ketone, methyl ethyl ketone, acetone and other ketone solvents, benzene, toluene, xylene, ethylbenzene, propylbenzene, Aromatic solvents such as isopropylbenzene, 3-methyl-2-oxazolidinone Heterocyclic compounds, acetonitrile, glutaronitrile, methoxyacetonitrile, propionitrile, and the like nitrile compounds such as benzonitrile. These organic solvents may be used alone or in combination of two or more.

When both water and an organic solvent are used, the mass ratio of the organic solvent to water is preferably 50% by mass or less.
The content of the organic solvent has an influence on the coating property and leakage current. The higher the organic solvent content, the better the coating property. Has the function of improving conductivity. For this reason, the resistance value of the hole injection layer 14a may be lowered to increase the amount of leakage current.

[Amine compound]
The polymer semiconductor paint can be made a more stably dispersed liquid by blending an amine compound. In addition, by adding an appropriate amount of an amine compound, it is possible to adjust the hydrogen ion index of the dispersion and prevent corrosion of the substrate and other layers.
The amine compound is not particularly limited as long as it is coordinated or bonded to a sulfo group or a phenolic hydroxyl group of (bisphenol S-phenolsulfonic acid) novolak resin. Some amine compounds (particularly amine compounds having a large molecular weight) shift the HOMO energy level of the hole injection layer 14a in an unfavorable direction by the action of its own HOMO energy level. Therefore, the amine compound is preferably a primary amine, a secondary amine, a tertiary amine, or a heterocyclic amine. Here, the coordination or bond refers to a bond form in which the distance between molecules of the sulfo group or phenolic hydroxyl group and the amine compound is shortened by donating / accepting electrons to each other.

Examples of the primary amine include monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, monohexylamine, monoheptylamine, monooctylamine, monodecylamine, monoundecylamine, monododecylamine, Monostearylamine, cyclohexylamine and the like can be mentioned.
Examples of secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, didecylamine, diundecylamine, didodecylamine, and dicyclohexylamine.
Examples of tertiary amines include trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, tridecylamine, triundecylamine, tridodecylamine, triphenyl. Examples include amine, tribenzylamine, dimethylhexylamine, dimethyldecylamine, dimethylhexadecylamine, dimethylbenzylamine, triethanolamine, dimethylaminoethanol, diethylaminoethanol and the like.
Examples of the heterocyclic amine include imidazole, N-methyl-imidazole, N-ethyl-imidazole, N-propyl-imidazole, N-butyl-imidazole, N-pentyl-imidazole, N-hexyl-imidazole, and N-heptyl. -Imidazole, N-octyl-imidazole, 1,2,4-trimethylimidazole, 1,2-dimethylimidazole, 2-methylimidazole, benzimidazole, pyridine, pyrimidine, pyrazine, quinazoline and the like. These may be used alone or in combination of two or more.

[Binder resin]
As described above, when a binder resin that is a non-conductive polymer is blended, the HOMO energy level of the hole injection layer 14a is shifted. However, when a binder resin is blended, water resistance, solvent resistance, and hardness can be improved. Therefore, you may contain binder resin in the range which can maintain practical luminous efficiency.
The binder resin may be a thermosetting resin or a thermoplastic resin as long as it is compatible or mixed and dispersible with the composite. For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyimides such as polyimide and polyamideimide; polyamides such as polyamide 6, polyamide 6,6, polyamide 12, and polyamide 11; polyvinylidene fluoride, polyvinyl fluoride, poly Fluorine resin such as tetrafluoroethylene, ethylenetetrafluoroethylene copolymer, polychlorotrifluoroethylene; vinyl resin such as polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyvinyl acetate, polyvinyl chloride; epoxy resin; oxetane resin; xylene resin; Polyamide silicone; Polyurethane; Polyurea; Melamine resin; Phenol resin; Polyether; Acrylic resin and these Copolymers.
Further, the binder resin can be used by adding a curing agent such as a cross-linking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity adjusting agent, and the like as necessary.

  Among the binder resins, one or more of polyurethane, polyester, acrylic resin, polyamide, polyimide, epoxy resin, and polyimide silicone are preferable because they can be easily mixed. An acrylic resin is suitable for applications such as an optical functional member because it has high hardness and excellent transparency.

(Manufacturing method of polymer semiconductor paint)
The polymer semiconductor coating is obtained by polymerizing a precursor monomer of polythiophene in the presence of (bisphenol S-phenolsulfonic acid) novolak resin.
Specifically, a precursor monomer of polythiophene is added to an aqueous solution of (bisphenol S-phenolsulfonic acid) novolak resin or a mixed solution of water and organic solvent, an oxidizing agent and an oxidation catalyst are added if necessary, and oxidative polymerization is performed. By doing so, a polymer semiconductor paint can be obtained. Since this method is a method in which ordinary oxidative polymerization is applied, a polymer semiconductor paint can be easily mass-produced.
(Bisphenol S-phenolsulfonic acid) When novolak resin is dissolved in the form of an alkali metal salt, ammonium salt or amine salt, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, perchloric acid, etc. in the polymer semiconductor coating It is preferable to add an inorganic acid or an organic acid to make it acidic.

Examples of oxidizing agents and oxidation catalysts include peroxodisulfates such as ammonium peroxodisulfate, sodium peroxodisulfate, and potassium peroxodisulfate; transition metal compounds such as ferric chloride, ferric sulfate, and cupric chloride. Metal oxides such as silver oxide and cesium oxide, peroxides such as hydrogen peroxide and ozone, organic peroxides such as benzoyl peroxide, oxygen, and the like can be used.
As a reaction solvent used when oxidative polymerization is performed, water or a mixed solvent of water and an organic solvent can be used. The organic solvent used here is a solvent that is miscible with water and can dissolve or disperse the (bisphenol S-phenolsulfonic acid) novolak resin or polythiophene, and examples thereof include those exemplified above. .

The obtained polymer semiconductor paint is preferably used after being finely divided by a homogenizer or a ball mill.
It is preferable to use a mixing and dispersing machine capable of applying a high shearing force for the fine graining. Examples of the mixing and dispersing machine include a homogenizer, a high-pressure homogenizer, and a bead mill. Among them, a high-pressure homogenizer is preferable.
Specific examples of the high-pressure homogenizer include a nanomizer manufactured by Yoshida Kikai Kogyo, a microfluidizer manufactured by Microfluidics, and an optimizer manufactured by Sugino Machine.
Examples of the dispersion process using the high-pressure homogenizer include a process in which the polymer semiconductor paint before the dispersion process is collided at high pressure and a process in which the polymer semiconductor paint is passed through an orifice or slit at a high pressure.
In addition, before or after the atomization, impurities may be removed by a technique such as filtration, ultrafiltration, or dialysis, and purification may be performed using a cation exchange resin, an anion exchange resin, a chelate resin, or the like.

When a dispersion treatment is performed by a mixing and dispersing machine, in principle, the temperature of the conductive polymer solution obtained by the treatment becomes high. Therefore, the temperature of the polymer semiconductor paint before the dispersion treatment is preferably -20 to 60 ° C, more preferably -10 to 40 ° C, and particularly preferably -5 to 30 ° C. Freezing can be prevented if the temperature of the polymer semiconductor coating is −20 or higher, and alteration of the polythiophene or (bisphenol S-phenolsulfonic acid) novolak resin can be prevented if the temperature is 60 ° C. or lower.
Moreover, you may cool the polymer semiconductor coating material after a dispersion process through the heat exchanger with a refrigerant | coolant temperature of -30-20 degreeC, for example.

  The finer particles are dispersed so that the average particle diameter of the polymer semiconductor coating is preferably 2000 nm or less, more preferably 500 nm or less, and particularly preferably 200 nm or less. If dispersion treatment is performed so that the average cumulant particle diameter of the composite is 2000 nm or less, the stability of the resulting polymer semiconductor coating is increased, and gelation and precipitation of the composite can be further prevented. Here, the cumulant average particle diameter is obtained from measurement of particle diameter distribution by a dynamic light scattering method. The cumulant average particle size is adjusted by mixing conditions (for example, pressure) in the dispersion step. Specifically, the higher the pressure, the smaller the average particle size.

  Moreover, since the (bisphenol S-phenolsulfonic acid) novolak resin has both hydrophilicity and lipophilicity, it is stably present not only in an aqueous solution but also in an organic solvent. Therefore, a complex of (bisphenol S-phenolsulfonic acid) novolak resin and polythiophene is also stably present in the organic solvent. Moreover, since the said composite does not need electrolytic oxidation polymerization, it can be manufactured simply.

(Method for forming hole injection layer)
The hole injection layer 14a can be formed by applying a polymer semiconductor paint to the base material 11 on which the anode 12 is patterned, and drying by heating.
Examples of coating methods include spin coaters, gravure coaters, roll coaters, curtain flow coaters, bar coaters, reverse coaters, kiss coaters, phantom coaters, rod coaters, air doctor coaters, knife coaters, blade coaters, cast coaters, screen coaters, etc. Application methods using the above coating machine, spraying methods such as spray coating such as air spray and airless spray, and dipping methods such as dip.
In heat drying, a dryer such as a hot air dryer or an infrared dryer can be used. Before heat drying, if necessary, air drying may be performed without heating. Moreover, it is also possible to heat-dry through the base material 11 by leaving it on the hot plate heated beforehand.
Although heating temperature is based also on melting | fusing point of the base material 11 to be used, it is preferable to set it as 100 to 300 degreeC. If it is 100 degreeC or more, the water | moisture content in a coating material can be removed rapidly, and if it is 300 degrees C or less, deterioration by a heat | fever can be prevented.

(Light emitting layer)
The light emitting layer 14b is a layer containing a light emitting material. Here, examples of the light emitting material include a dye light emitting material, a metal complex light emitting material, and a polymer light emitting material.
Examples of the dye-based luminescent material include cyclopentamine derivatives, tetraphenifbutadiene derivatives, triphenylamine derivatives, distyrylarylene derivatives, silole derivatives, thiophene ring compounds, pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives. , Triphenylamine derivatives, oxadiazole dimers, porazoline dimers, and the like.
Examples of the metal complex light emitting material include an aluminum quinolyl complex, a benzoquinolyl complex, a beryllium complex, a benzoxazole zinc complex, a benzothiazole zinc complex, an azomethylzinc complex, a porphyrin zinc complex, a europium complex, or a central metal, Examples thereof include metal complexes having a rare earth metal such as Al, Zn, Be, etc. or Tb, Eu, Dy, etc., and having an oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure, etc. as a ligand.
Examples of the polymeric light-emitting material include polyparaphenylene vinylene derivatives, polythiophene derivatives (those not doped with acid), polyparaphenylene derivatives, and polyvinylcarbazole derivatives. Moreover, what polymerized said pigment-type luminescent material and metal complex luminescent material etc. are mentioned.

  The thickness of the light emitting layer 14b is appropriately selected depending on the light emitting material to be used, but considering light emitting characteristics such as light emitting voltage and light emitting efficiency, it is preferably 1 nm to 1 μm, and more preferably 5 to 500 nm. 10 to 200 nm is more preferable.

  Examples of the method for forming the light emitting layer 14b include vapor deposition, inkjet, spin coating, casting, dipping, bar coating, blade coating, roll coating, gravure coating, flexographic printing, and spin coating. Is mentioned. Among these, the vapor deposition method, the spin coat method, and the ink jet method are preferable.

(Electron injection layer)
The electron injection layer 14 c is formed between the light emitting layer 14 b and the cathode 13 so as to be in contact with the cathode 13, moves electrons from the cathode 13 toward the light emitting layer 14 b, and performs electron injection in the light emitting layer 14 b and the cathode 13. It is a layer that works to alleviate energy barriers.
As a material for forming the electron injection layer 14c, 2,9-dimethyl-4,7-diphenyl-1,20-phenanthroline (BCP), 2- (4-biphenylyl) -5-4 (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), silole derivatives, lithium fluoride (LiF) and the like.
The thickness of the electron injection layer 14c is preferably 0.1 nm to 1 μm, and more preferably 0.2 to 500 nm.

<Base material>
The substrate 11 is made of a transparent sheet or plate.
Specific examples of the substrate 11 include a sheet mainly composed of glass such as soda lime glass and quartz glass, and a transparent thermoplastic resin such as polyvinyl chloride, acrylic resin, polystyrene, and amorphous polyethylene terephthalate.

<Anode>
The anode 12 is an electrode made of a transparent conductive layer. Examples of the transparent electrode layer include a conductive metal oxide layer and a metal layer. Examples of the conductive oxide include indium oxide, zinc oxide, tin oxide, and tin-doped indium oxide (ITO). Among these, ITO is preferable in terms of transparency and inherent work function value. Platinum, silver, copper and the like.
Examples of the method for forming the anode 12 include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method.
Although the anode 12 may be formed into a pattern, the pattern can be formed by a method in which an anode material is attached through a mask in which a pattern is previously formed, or a group in which an anode material layer is previously formed on the entire surface. A method is available in which a material is obtained, cut into a desired size, and then etched. The latter method can form a substrate with an anode pattern more easily and inexpensively.

The thickness of the anode 12 is preferably 10 nm to 10 μm, more preferably 20 nm to 5 μm, and still more preferably 50 to 2 μm. If the thickness of the anode 12 is not less than the lower limit, the conductivity of the anode 12 is improved, and if it is not more than the upper limit, the transparency of the anode 12 is improved.
In addition, the surface of the anode 12 is preferably excellent in flatness in order to improve uniformity when forming a thin film after the hole injection layer 14a. Specifically, the surface roughness of the hole injection layer 14a is preferably an average surface roughness Ra of 10 nm or less, and more preferably Ra of 1 nm or less.

<Cathode>
The cathode 13 is made of a metal layer having a work function having an absolute value smaller than the LUMO energy level of the light emitting layer 14b. Examples of the material satisfying this include indium, aluminum, magnesium, calcium, magnesium-indium alloy, magnesium-aluminum alloy, aluminum-lithium alloy, aluminum-scandium-lithium alloy, and magnesium-silver alloy.

The thickness of the cathode 13 is not a problem as long as electrons can be supplied to the electron injection layer 14c. However, since it also needs a function as a contact point with an external circuit, it is preferably 10 nm or more.
Further, the thickness of the cathode 13 is more preferably 10 nm to 10 μm, further preferably 20 nm to 1 μm, and particularly preferably 50 nm to 500 nm. When the thickness of the cathode 13 is equal to or greater than the lower limit, the conductivity of the cathode 13 is improved and the durability with the contact is also improved.

<Operation effect of OEL element>
In the OEL element 10 of the above embodiment, the hole injection layer 14a contains (bisphenol S-phenolsulfonic acid) novolak resin and polythiophene, and does not contain a binder resin of a nonconductive polymer. It exhibits a reasonably high electrical resistance value (specifically, a specific resistance value of about 10 ⁵ Ωcm) for the hole injection layer 14a. Therefore, the leakage current at the time of light emission of the OEL element 10 can be sufficiently suppressed. In addition, since it is not necessary to contain a non-conductive binder resin in order to suppress leakage current, there is no change in the HOMO energy level, and a reduction in light emission efficiency can be prevented.

<Other Embodiments of OEL Element>
In addition, this invention is not limited to the said embodiment.
In the present invention, each of the hole injection layer and the electron injection layer has a single-layer structure. In order to further smooth the energy barrier for hole injection and electron injection, a plurality of hole injection layers and electron injection layers are provided. Also good. For example, an OEL device having two hole injection layers and two electron injection layers may be used. In this case, the hole injection layer on the side in contact with the light emitting layer is the hole transport layer, and the electron injection on the side in contact with the light emitting layer is used. The layer may be referred to as an electron transport layer.
However, as the hole injection layer and the electron injection layer are multilayered and the slope of the energy barrier between each layer is reduced, the luminous efficiency increases. However, the multilayered layer becomes more difficult to manage the thickness and the manufacturing cost also increases. Since it rises, it is usually made into 1 to 2 layers.
Moreover, the hole injection layer should just be provided with the polymer semiconductor film formed from the polymer semiconductor coating material, and may be provided with layers other than a polymer semiconductor film.

Examples are shown below, but the present invention is not limited to the examples.
Production Example 1 Production of ITO Patterned Substrate A commercially available glass with ITO film for OEL (ITO surface roughness Ra less than 10 nm, thickness 0.5 mm) is cut into a size of 20 × 20 mm using a glass cutter. (Chip A). The center of the chip A was masked with a 3 mm wide mending tape, and then immersed in aqua regia (hydrochloric acid: nitric acid = 1: 3, volume ratio) for 10 minutes to remove the ITO film other than the mask part on the chip A. (Chip B). After thoroughly rinsing the chip B with ion-exchanged water, the chip B was further rinsed with running water, and after wiping off the moisture, it was carefully peeled off so that the adhesive of the mending tape did not remain, to obtain a substrate with an ITO pattern.

(Production Example 2)
Cleaning the substrate with ITO pattern The substrate with ITO pattern was subjected to ultrasonic cleaning for 10 minutes with a solid detergent (Wako Pure Chemical Industries Contaminon O: 3% aqueous solution) and then further with ion-exchanged water for 10 minutes. Sonic cleaning was performed to obtain a solid detergent cleaned substrate.
Subsequently, this solid detergent cleaned substrate was subjected to ultrasonic cleaning with a neutral liquid detergent (Merck Co., Ltd. Extra MA02 neutral: 2% aqueous solution) for 10 minutes, and then further subjected to ultrasonic cleaning with ion exchange water for 10 minutes. To obtain a liquid detergent cleaned substrate.
Subsequently, the liquid detergent cleaned substrate was subjected to ultrasonic cleaning for 10 minutes in acetone, and then subjected to ultrasonic cleaning for 10 minutes in IPA (isopropyl alcohol) to obtain a solvent cleaned substrate. .
And after drying the said solvent washing | cleaning base material fully, it wash | cleaned for 20 minutes with the ozone washing machine (Filgen UV253E), and the chip | tip after washing | cleaning was obtained.

Production Example 3 Preparation of Polymer Semiconductor Coating A 1.42 g (0.01 mol) of 3,4-ethylenedioxythiophene and 12.0 g of (bisphenol S-phenolsulfonic acid) novolak in 100 ml of ion-exchanged water Resin (X in the general formula (2) is Na. Solid content concentration 35.6% by mass, bisphenol S / sodium phenol sulfonate = 3/7 (mol / mol), mass average molecular weight: about 15,000, (Manufactured by Konishi Chemical Co., Ltd.) and a solution prepared by dissolving 4.26 g of concentrated sulfuric acid were mixed at 20 ° C. to obtain a monomer dispersion.
2.84 g (0.012 mol) of ammonium persulfate and 0.14 g (0.35 mmol) of ferric sulfate dissolved in 20 ml of ion-exchanged water while stirring the monomer dispersion thus obtained at 20 ° C. The oxidation catalyst solution was added and stirred for 16 hours to react.
The resulting reaction solution was dialyzed to remove unreacted monomers, oxidizing agent and oxidation catalyst, and after dispersion treatment at a pressure of 100 MPa using a high pressure homogenizer (Nanomizer manufactured by Yoshida Kikai Kogyo Co., Ltd.), ion exchange resin IR120BH (organo stock) 20 g (wet) manufactured by company) and 10 g (wet) IRA96BS (manufactured by Organo Corporation) were added and stirred for 3 hours, followed by filtration. This ion exchange resin treatment was performed three times in total, concentrated under reduced pressure on a rotary evaporator, and dispersed with about 1.5% by mass of blue (bisphenol S-phenolsulfonic acid) novolac resin doped poly (3,4-ethylenedioxythiophene) A polymer semiconductor paint A comprising a liquid was obtained.

(Production Example 4) Preparation of Polymer Semiconductor Coating B (Bisphenol S-phenolsulfonic acid) The same procedure as in Production Example 3 was carried out except that the amount of novolak resin was changed to 16.0 g. ) A polymer semiconductor coating B comprising a novolac resin-doped poly (3,4-ethylenedioxythiophene) dispersion was obtained.

(Production Example 5) Preparation of polystyrene sulfonic acid 206 g of sodium styrene sulfonate was dissolved in 1000 ml of ion-exchanged water and stirred at 80 ° C., and 1.14 g of ammonium persulfate oxidizing agent solution previously dissolved in 10 ml of water was added. The solution was added dropwise for 20 minutes, and the solution was stirred for 2 hours.
1000 ml and 10,000 ml of ion-exchanged water diluted with 10% by mass of sulfuric acid diluted to 10% by mass were added to the sodium styrenesulfonate-containing solution thus obtained, and about 10,000 ml of the polystyrenesulfonic acid-containing solution was removed using an ultrafiltration method. Then, 10,000 ml of ion-exchanged water was added to the remaining liquid, and about 10,000 ml of solution was removed using an ultrafiltration method. The above ultrafiltration operation was repeated three times.
Furthermore, about 10,000 ml of ion-exchanged water was added to the obtained filtrate, and about 10,000 ml of solution was removed using an ultrafiltration method. This ultrafiltration operation was repeated three times.
The ultrafiltration conditions were as follows.
Molecular weight cut off of ultrafiltration membrane: 30K
Cross flow type Supply liquid flow rate: 3000 ml / min Membrane partial pressure: 0.12 Pa
Water in the obtained solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid.

(Production Example 6) Preparation of Polymer Semiconductor Coating C 7.3 g of 3,4-ethylenedioxythiophene and 43.6 g of the polystyrene sulfonic acid obtained in Production Example 5 dissolved in 2000 ml of ion-exchanged water Were mixed at 20 ° C.
While maintaining the mixed solution thus obtained at 20 ° C. and stirring, 29.64 g of ammonium persulfate dissolved in 200 ml of ion exchange water and 8.0 g of ferric sulfate oxidation catalyst solution were slowly added, The reaction was stirred for 3 hours.
2000 ml of ion-exchanged water was added to the resulting reaction solution, and about 2000 ml of solution was removed using an ultrafiltration method. This operation was repeated three times.
Then, 200 ml of sulfuric acid diluted to 10% by mass and 2000 ml of ion-exchanged water are added to the treatment liquid that has been subjected to the filtration treatment, and about 2000 ml of the treatment liquid is removed using an ultrafiltration method. Ion exchange water was added and about 2000 ml of liquid was removed using ultrafiltration. This operation was repeated three times.
Furthermore, 2000 ml of ion-exchanged water was added to the obtained treatment liquid, and about 2000 ml of the treatment liquid was removed using an ultrafiltration method. This operation was repeated 5 times to obtain a polymer semiconductor paint C composed of about 1.2% by mass of a blue PEDOT / PSS aqueous dispersion.

(Production Example 7) Preparation of Polymer Semiconductor Coating D To 1000 ml of the PEDOT / PSS aqueous dispersion obtained in Production Example 6, 24 g of polystyrene sulfonic acid obtained in Production Example 5 and 200 ml of ion-exchanged water were added, and a high-pressure homogenizer ( Using a nanomizer manufactured by Yoshida Kikai Kogyo Co., Ltd., dispersion treatment was performed at a pressure of 100 MPa to obtain a polymer semiconductor paint D composed of a PEDOT / PSS aqueous dispersion with increased resistance.

Example 1
Polymer semiconductor coating A was applied onto the cleaned chip using a spin coater (Mikasa Corporation MS-A100). The coating conditions at that time were 3,000 rpm / 60 seconds. Subsequently, it was left to dry on a hot plate preheated to 150 ° C. for 15 minutes to form a hole injection layer, and a chip A was obtained.
Next, a light emitting layer made of tris (8-quinolinolato) aluminum (Alq3) is formed on the hole injection layer of chip A using a vapor deposition apparatus (Eiko EO-6S Co., Ltd.) to obtain chip A ′. It was. The degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa or less, and the thickness of the light emitting layer was 50 nm.
Next, an electron injection layer made of lithium fluoride (LiF) was formed on the light emitting layer surface of the chip A ′ using a vapor deposition apparatus similar to the above to obtain a chip A ″. 1.0 × 10 ⁻⁴ Pa or less, and the thickness of the electron injection layer was 0.5 nm.
Next, an evaporation mask prepared in advance with a width of 3 mm is arranged on the electron injection layer of the chip A ″ so as to be orthogonal to the ITO pattern of the chip A ″, and a cathode made of aluminum is formed using the same evaporation apparatus as described above. Formed. The degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa or less, and the film thickness of Al was 130 nm.
Thus, OEL element A was obtained.

(Example 2)
An OEL element B was obtained in the same manner as in Example 1 except that the polymer semiconductor paint B obtained in Production Example 4 was used instead of the polymer semiconductor paint A.

(Comparative Example 1)
An OEL element C was obtained in the same manner as in Example 1 except that the polymer semiconductor paint C obtained in Production Example 6 was used instead of the polymer semiconductor paint A.

(Comparative Example 2)
An OEL element D was obtained in the same manner as in Example 1 except that the polymer semiconductor paint D obtained in Production Example 7 was used instead of the polymer semiconductor paint A.

<Evaluation>
About the OEL element of each Example and each comparative example, the HOMO energy level of the positive hole injection layer, the leakage current, and the luminous efficiency were measured as follows. The measurement results are shown in Table 1.

[Measurement of HOMO energy level]
A polymer semiconductor paint was dropped onto a commercially available PTFE (polytetrafluoroethylene) plate, and then dried in an oven at 150 ° C. to obtain a thin film sample. About this thin film sample, the HOMO energy level was measured using the photoelectron spectrometer (Riken Keiki Co., Ltd. AC-3, light quantity: 10nW, measurement error: +/- 0.02eV).

[Measurement of leakage current and luminous efficiency]
Using a DC voltage / current source / monitor (ADC 6241A) and a luminance meter (LS-100, Konica Minolta Sensing Co., Ltd.), the current density at a voltage of 1.0 V was measured and used as a leakage current value.
Further, the current density and luminance at a voltage of 6.0 V were measured, and the luminous efficiency was calculated from these values. In order to prevent deterioration due to atmospheric oxygen and moisture, the measurement was performed in a chamber filled with dry nitrogen.

  Using a polymer semiconductor paint A or a polymer semiconductor paint B containing a novolak resin having a bisphenol S unit represented by the general formula (1) and a phenolsulfonic acid unit represented by the general formula (2) and polythiophene The leakage current value of the organic EL element A of Example 1 and the organic EL element B of Example 2 in which the hole injection layer was formed was sufficiently small. Moreover, the luminous efficiency also showed a high value.

In contrast to the above examples, the organic EL device C of Comparative Example 1 in which the hole injection layer is formed using PEDOT / PSS has the same HOMO energy level, but has a large leakage current value, and accordingly, luminous efficiency. Had fallen.
Further, the organic EL element D of Comparative Example 2 in which the hole injection layer was formed using PEDOT / PSS whose resistance was increased by increasing the amount of PSS had a leakage current value smaller than that of Comparative Example 1, but the HOMO energy Luminous efficiency was reduced due to the shift of the level and the increased hole injection barrier.

Since the polymer semiconductor coating film obtained by the present invention has a conductivity of about 10 ⁵ Ω · cm by itself, in addition to the hole injection layer of the OEL element, the conductive packaging material, the electron It can also be used for products that require antistatic properties such as component containers (carrier tape, cover tape, tray, magazine, bulk case, OA equipment cover, etc.). For example, semiconductor devices such as IC, LSI, VLSI, LCD (liquid crystal display), PDP (plasma display), silicon wafer, hard disk, liquid crystal substrate, magnetic device, etc. Examples thereof include an optical device, a magneto-optical device, and electronic components that form these. Furthermore, the polymer semiconductor coating film of the present invention can be used for home appliances and daily necessities that require antistatic properties.

DESCRIPTION OF SYMBOLS 10 OEL element 11 Base material 12 Anode 13 Cathode 14 Light emission part 14a Hole injection layer 14b Light emission layer 14c Electron injection layer

Claims (1)

A light emitting unit is provided between a pair of electrodes, and the light emitting unit includes a light emitting layer, a hole injection layer that moves holes from one electrode to the light emitting layer, and an electron from the other electrode to the light emitting layer. In an organic electroluminescence device having an electron transfer layer that moves
The hole injection layer includes a polymer semiconductor film formed of a polymer semiconductor paint, and the polymer semiconductor paint is represented by the bisphenol S unit represented by the following general formula (1) and the following general formula (2). An organic electroluminescence device comprising a composite of a novolak resin having a phenolsulfonic acid unit represented by a polymer of thiophene or a derivative thereof.

(In the formula, X is any one of H, Li, Na, K, NH _(4-Y) R _Y , and Y is an integer from 0 to 4. R is from 1 to C carbon atoms. When Y is 2 or more, which is any alkyl group of 8, they may be the same or different.The hydrogen constituting the aromatic ring of the bisphenol S unit and the phenolsulfonic acid unit is a methyl group or a methoxy group. And may be substituted with a group, and 1 ≦ m <10000 and 1 ≦ n <10000.)

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