JP2016113538A - Metal oxide-containing layer forming composition, electronic device, and method for producing electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition which can easily form a metal oxide-containing layer having high electrical properties and moderate film hardness, an electronic device comprising the metal oxide-containing layer, and a method for easily producing the electronic device.SOLUTION: A metal oxide-containing layer forming composition comprises unsaturated carboxylic acid metal salt represented by formula (I), and polyvinyl acetal resin (R-Rindependently represent H or any substituent; M is a m-valent metal atom; m is an integer of 2-5; m CRR=CR-COOmay be the same or different).SELECTED DRAWING: Figure 3

Description

  The present invention relates to a metal oxide-containing layer forming composition, an electronic device, and a method for producing an electronic device.

  In recent years, electronic devices using organic semiconductors, especially organic transistor elements (OFETs), organic electroluminescent elements (OLEDs), and organic thin film solar cells (OPVs) have been actively developed. Since a device using an organic semiconductor can maintain flexibility by using a flexible base material as a base material, it has a feature that it can be installed in various situations.

  The OPV usually has a configuration in which an active layer is sandwiched between a pair of electrodes, but a buffer layer may be provided between the electrode and the active layer for the purpose of improving charge transport efficiency. is there. The buffer layer can be generally classified into an electron extraction layer and a hole extraction layer. Among these, OPV using a metal oxide such as zinc oxide (ZnO) as a material for the electron extraction layer has been reported.

  For example, Patent Document 1 describes an OPV using a zinc oxide-containing (ZnO) layer as an electron extraction layer. In addition, by using zinc diacrylate to form the zinc oxide-containing layer, a method capable of uniformly forming a zinc oxide-containing layer that is harder than the zinc oxide-containing layer formed from a dispersion of zinc oxide nanoparticles Is described.

  Patent Document 2 describes that a titanium oxide-containing layer containing polyvinyl butyral is formed from a dispersion containing polyvinyl butyral and titanium oxide nanoparticles.

International Publication No. 2013/180230 Pamphlet JP-A-11-204152

  In order to produce an electronic device using an organic semiconductor with high productivity, production by a roll-to-roll method using a flexible substrate is preferable. For this purpose, it is preferable that a metal oxide-containing layer having high electrical characteristics and appropriate film hardness can be produced from a highly stable ink by a simple method. However, according to the study by the present inventors, when a metal oxide-containing layer is formed according to the methods described in Patent Documents 1 and 2, a metal oxide-containing layer that achieves both high electrical characteristics and appropriate film hardness is obtained. This proved to be difficult and requires further investigation. Further, it has been found that the ink obtained by the method described in Patent Document 2 has insufficient stability and the film hardness obtained tends to be insufficient. This is because, due to the particle size (10 nm or more) of the metal oxide nanoparticles used in the dispersion, the film hardness of the metal oxide-containing layer that can be formed is still soft even when a binder resin is added. It turned out to be.

  The present invention has been made in view of the above problems, and a composition capable of easily forming a metal oxide-containing layer having high electrical characteristics and appropriate film hardness, and an electronic device provided with the metal oxide-containing layer It is another object of the present invention to provide a method for easily manufacturing the electronic device.

  As a result of intensive studies, the present inventors have solved the above problems and achieved the present invention by using a composition containing a specific unsaturated carboxylic acid metal salt and a polyvinyl acetal resin.

That is, the gist of the present invention is as follows.
[1] A metal oxide-containing layer forming composition comprising an unsaturated carboxylic acid metal salt represented by the formula (I) and a polyvinyl acetal resin.

(In the formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom or an arbitrary substituent, M is an m-valent metal atom, and m is an integer of 2 or more and 5 or less. M m CR ¹ R ² ═CR ³ —COO ⁻ may be the same or different from each other.)
[2] The metal oxide-containing layer forming composition according to [1], wherein the unsaturated carboxylic acid metal salt has 3 to 12 carbon atoms.
[3] In the formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom or an alkyl group which may have a substituent, according to [1] or [2] A composition for forming a metal oxide-containing layer.
[4] In the formula (I), M is any metal selected from a transition metal element in the fourth period of the periodic table, a Group 12 element in the periodic table, a Group 13 element in the periodic table, and a Group 14 element in the periodic table The composition for forming a metal oxide-containing layer according to any one of [1] to [3], which is an atom.
[5] The composition for forming a metal oxide-containing layer according to any one of [1] to [4], wherein M is a zinc atom in the formula (I).
[6] A method for manufacturing an electronic device including a metal oxide-containing layer, wherein the metal oxide-containing layer manufacturing process includes forming a metal oxide-containing layer according to any one of [1] to [5] The manufacturing method of the electronic device characterized by including the process of apply | coating the composition for coating, and the process of heat-processing after the said application | coating.
[7] The method for manufacturing an electronic device according to [6], wherein the electronic device is a photoelectric conversion element.
[8] An electronic device having a metal oxide-containing layer containing a metal oxide and a polyvinyl acetal resin, wherein the content of the polyvinyl acetal resin in the metal oxide-containing layer is 1% by mass or more and 60% by mass. % Or less electronic device.

  According to the present invention, an electronic device including a metal oxide-containing layer having high electrical characteristics and appropriate film hardness can be easily produced.

It is sectional drawing which represents typically the structure of the field effect transistor element as one Embodiment of this invention. It is sectional drawing which represents typically the structure of the electroluminescent element as one Embodiment of this invention. It is sectional drawing which represents typically the structure of the photoelectric conversion element as one Embodiment of this invention. It is sectional drawing which represents typically the structure of the solar cell as one Embodiment of this invention. It is sectional drawing which represents typically the structure of the solar cell module as one Embodiment of this invention. It is the visible and ultraviolet spectroscopy (UV-Vis) spectrum of the zinc oxide containing layer measured in Example 4.

Embodiments of the present invention will be described below. However, the description of the constituent elements to be described is an example (representative example) of the embodiments of the present invention, and the present invention is specified to these contents as long as the gist thereof is not exceeded. Not.
Note that in the structures of the present invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated. Hereinafter, the metal oxide-containing layer forming composition according to the present invention will be described.

<1. Metal oxide-containing layer forming composition>
The composition for forming a metal oxide-containing layer according to the present invention contains an unsaturated carboxylic acid metal salt represented by the following formula (I) and a polyvinyl acetal resin. In addition, the composition for metal oxide content layer formation concerning this invention can be produced by mixing this unsaturated carboxylic acid metal salt and polyvinyl acetal resin.

<1.1. Unsaturated carboxylic acid metal salt>
The unsaturated carboxylic acid metal salt contained in the metal oxide-containing layer forming composition according to the present invention is an unsaturated carboxylic acid metal salt represented by the formula (1).

  The unsaturated carboxylic acid metal salt represented by the formula (I) is a metal salt of an α, β-unsaturated carboxylic acid, and m is an integer of 2 or more and 5 or less. Specifically, it is a dicarboxylic acid metal salt (m = 2), a tricarboxylic acid metal salt (m = 3), a tetracarboxylic acid metal salt (m = 4), or a pentacarboxylic acid metal salt (m = 5).

  In the present invention, an unsaturated carboxylic acid metal is used to form a metal oxide-containing layer with few impurities from a metal oxide-containing layer forming composition containing an unsaturated carboxylic acid metal salt represented by the formula (I). A larger proportion of metal atoms in the salt is preferred. Therefore, it is preferable that m is 3 or less. On the other hand, in order to prevent the bond between the carboxylic acid and the metal atom from becoming weak, it is preferable to convert the unsaturated carboxylic acid metal salt to the metal oxide at a temperature that is not too high. From this viewpoint, m is preferably 2 or more. As described above, as the unsaturated carboxylic acid metal salt, a dicarboxylic acid metal salt or a tricarboxylic acid metal salt is preferable, and a dicarboxylic acid metal salt is particularly preferable because conversion at an appropriate temperature is possible.

  In the formula (I), M is a divalent to pentavalent metal atom. Specifically, as the divalent metal atom, titanium (II) atom, vanadium (II) atom, chromium (II) atom, manganese (II) atom, iron (II) atom, cobalt (II) atom, nickel (II) atoms, divalent transition metal atoms such as copper (II) atoms; divalent typical metal atoms such as zinc (II) atoms, tin (II) atoms, and lead (II) atoms. Trivalent metal atoms include trivalent transition metals such as scandium (III) atoms, titanium (III) atoms, chromium (III) atoms, manganese (III) atoms, iron (III) atoms, and cobalt (III) atoms. Atoms: Trivalent typical metal atoms such as aluminum (III) atoms, gallium (III) atoms, indium (III) atoms and the like. Examples of the tetravalent metal atom include a titanium (IV) atom, a tin (IV) atom, and a lead (IV) atom. Examples of pentavalent metal atoms include vanadium (V) atoms.

  In addition, in this specification, a typical metal atom refers to the atom of a metal element of 1st group, 2nd group, and 12th group-18th group of a periodic table. The transition metal atom refers to an atom of a metal element belonging to Group 3 to Group 11 of the periodic table. In the present specification, the periodic table refers to a recommended version of IUPAC 2005 (Recommendations of IUPAC 2005).

  Preferable examples of M include atoms that can easily form carboxylic acid metal salts. Specifically, the metal atom chosen from the transition metal element of the 4th period of a periodic table, the periodic table group 12 element, the periodic table group 13 element, and the periodic table group 14 element is mentioned. The metal atom selected from the transition metal elements in the fourth period of the periodic table is preferably a scandium atom, a titanium atom, a vanadium atom, a chromium atom, a manganese atom, an iron atom, a cobalt atom, a nickel atom, or a copper atom. The metal atom selected from Group 12 elements of the periodic table is preferably a zinc atom. The metal atom selected from Group 13 elements of the periodic table is preferably an indium atom, a gallium atom, or an aluminum atom. Preferred examples of the metal atom selected from Group 14 elements of the periodic table include a tin atom and a lead atom. M is preferably a titanium atom, a vanadium atom, an iron atom, a nickel atom, a copper atom, a zinc atom, an indium atom, a gallium atom, an aluminum atom or a tin atom in that the corresponding metal oxide has a high carrier mobility. . Among these, a titanium atom, a nickel atom, a copper atom, a zinc atom, an indium atom or a tin atom is more preferable, and a zinc atom is particularly preferable. The zinc atom has a high solubility of unsaturated zinc carboxylate, a high uniformity of the film obtained by coating and forming a metal oxide-containing layer-forming composition containing unsaturated zinc carboxylate, and The zinc oxide-containing layer is particularly preferable because it has good physical properties and high carrier mobility. In the present specification, the carrier mobility refers to either electron mobility or hole mobility as described later.

R ¹ , R ² and R ^{3 in} formula (I) are not particularly limited as long as the metal oxide-containing layer according to the present invention functions, and R ¹ , R ² and R ³ are each independently It is a hydrogen atom or an arbitrary substituent. Preferred examples of the substituent include a halogen atom, a hydroxyl group, a cyano group, an amino group, a silyl group, a boryl group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aromatic hydrocarbon group, and an aromatic heterocyclic group. It is done. The amino group, silyl group, boryl group, alkyl group, alkenyl group, alkynyl group, alkoxy group, aromatic hydrocarbon group and aromatic heterocyclic group may further have a substituent.

  As the halogen atom, a fluorine atom is preferable.

  Examples of the amino group include aromatic substituted amino groups such as a diphenylamino group, a ditolylamino group, and a carbazolyl group.

  As the silyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include a trimethylsilyl group and a triphenylsilyl group.

  Examples of the boryl group include aromatic substituted boryl groups such as a dimesitylboryl group.

  As an alkyl group, a C1-C20 thing is preferable, for example, a methyl group, an ethyl group, i-propyl group, t-butyl group, or a cyclohexyl group is mentioned.

  As the alkenyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include a vinyl group, a styryl group, and a diphenylvinyl group.

  As the alkynyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include a methylethynyl group, a phenylethynyl group, and a trimethylsilylethynyl group.

  As the alkoxy group, those having 2 to 20 carbon atoms are preferable. For example, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, ethylhexyloxy group, benzyloxy And straight-chain or branched alkoxy groups such as t-butoxy group.

  As the aromatic hydrocarbon group, those having 6 to 20 carbon atoms are preferable. The aromatic hydrocarbon group may be any of a monocyclic aromatic hydrocarbon group, a condensed polycyclic aromatic hydrocarbon group, and a ring-linked aromatic hydrocarbon group. Examples of the monocyclic aromatic hydrocarbon group include a phenyl group. Examples of the condensed polycyclic aromatic hydrocarbon group include a phenanthryl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyrenyl group, and a perylenyl group. Examples of the ring-linked aromatic hydrocarbon group include a biphenyl group and a terphenyl group. Among these, a phenyl group or a naphthyl group is preferable.

  As the aromatic heterocyclic group, those having 2 to 20 carbon atoms are preferable, for example, pyridyl group, thienyl group, furyl group, oxazolyl group, thiazolyl group, oxadiazolyl group, benzothienyl group, dibenzofuryl group, dibenzothienyl group. , Pyrazinyl group, pyrimidinyl group, pyrazolyl group, imidazolyl group, and phenylcarbazolyl group. Among these, a pyridyl group, a thienyl group, a benzothienyl group, a dibenzofuryl group, a dibenzothienyl group, or a phenanthryl group is preferable.

  In addition, as a substituent that the amino group, silyl group, boryl group, alkyl group, alkenyl group, alkynyl group, alkoxy group, aromatic hydrocarbon group or aromatic heterocyclic group may have, there are no particular restrictions. For example, the group mentioned by the above-mentioned monovalent organic group is mentioned. In addition, when the monovalent organic group has a substituent, the preferable carbon number of the monovalent organic group described above is the carbon number including the substituent.

Among the above, R ¹ , R ^2, and R ³ are each independently a hydrogen atom, an alkyl group that may have a substituent, a carboxyl group, or an alkoxycarbonyl group that may have a substituent. Is preferred. Specific examples of these α, β-unsaturated carboxylic acids include acrylic acid (R ¹ = R ² = R ³ = H), methacrylic acid (R ¹ = R ² = H, R ³ = CH ₃ ). , Ethacrylic acid (R ¹ = R ² = H, R ³ = C ₂ H ₅ ), crotonic acid (R ¹ = CH ₃ , R ² = R ³ = H), isocrotonic acid (R ¹ = H, R ² = CH ₃ , R ³ = H), angelic acid (R ¹ = H, R ² = CH ₃ , R ³ = CH ₃ ), tiglic acid (R ¹ = CH ₃ , R ² = H, R ³ = CH ₃ ) 2-pentenoic acid (R ¹ = C ₂ H ₅ , R ² = R ³ = H), 2-hexenoic acid (R ¹ = C ₃ H ₇ , R ² = R ³ = H), 2-heptenoic acid ( R ¹ = C ₄ H ₉ , R ² = R ³ = H), 2-octenoic acid (R ¹ = C ₅ H ₁₁ , R ² = R ³ = H), 2-nonenoic acid (R ¹ = C ₆ H ₁₃ , R ² = R ³ = H), 2-decenoic acid (R ¹ = C ₇ H ₁₅ , R ² = R ³ = H), 2-undecenoic acid (R ¹ = C ₈ H ₁₇ , R ² = R ³ = H), 2-dodecenoic acid (R ¹ = C ₉ H ₁₉ , R ² = R ³ = H) ), Fumaric acid (R ¹ = COOH, R ² = R ³ = H), maleic acid (R ¹ = H, R ² = COOH, R ³ = H), itaconic acid (R ¹ = R ² = H, R ³ = CH ₂ COOH), citraconic acid (R 1 = CH ₃ , R ² = COOH, R ³ = H), mesaconic acid (R ¹ = COOH, R ² = CH ₃ , R ³ = H), monomethyl fumarate ( R ¹ = COOCH ₃ , R ² = R ³ = H), monoethyl fumarate (R ¹ = COOC ₂ H ₅ , R ² = H, R ³ = H), monobutyl fumarate (R ¹ = COOC ₄ H ₉ , R ² = R ³ = H), monooctyl fumarate (R ¹ = COOC ₈ H ₁₇ , R ² = R ³ = H), monomethyl maleate (R ¹ = H, R ² = COOCH ₃ , R ³ = H), monoethyl maleate (R ¹ = H, R ² = COOC ₂ H ₅ , R ³ = H), monobutyl maleate (R ¹ = H, R ² = COOC ₄ H ₉ , R ³ = H), monooctyl maleate (R ¹ = H, R ² = COOC ₈ H ₁₇ , R ³ = H), monomethyl itaconate (R ¹ = R ² = H, R ³ = CH ₂ COOCH ₃ ), itacon Monoethyl acid (R ¹ = R ² = H, R ³ = CH ² COOC ₂ H ₅ ), monobutyl itaconate (R ¹ = R ² = H, R ³ = CH ₂ COOC ₄ H ₉ ), citraconic acid monomethyl (R ¹ = CH ₃ , R ² = COOCH ₃ , R ³ = H), monoethyl citraconic acid (R ¹ = CH ₃ , R ² = COOC ₂ H ₅ , R ³ = H), monobutyl citraconic acid (R ¹ = CH ₃ , R ² = COOC ₄ H ₉ , R ³ = H), monooctyl citraconic acid (R ¹ = C H ₃ , R ² = COOC ₈ H ₁₇ , R ³ = H), monomethyl mesaconate (R ¹ = COOCH ₃ , R ² = CH ₃ , R ³ = H), monoethyl mesaconate (R ¹ = COOC ₂ H ₇ R ² = CH ₃ , R ₃ = H), monobutyl mesaconate (R ¹ = COOC ₄ H ₉ , R ² = CH ₃ , R ³ = H), or monooctyl mesaconic acid (R ¹ = COOC ₈ H ₁₇ R ² = CH ₃ , R ³ = H).

In particular, from the viewpoint that the formation of the metal oxide-containing layer can proceed smoothly, R ¹ , R ² and R ³ are each independently a hydrogen atom or an alkyl group which may have a substituent. preferable. Specifically, acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, isocrotonic acid, angelic acid, tiglic acid, 2-pentenoic acid, 2-hexenoic acid, 2-heptenoic acid, 2-octenoic acid, 2-nonenoic acid 2-decenoic acid, 2-undecenoic acid, or 2-dodecenoic acid.

Among them, R ³ is a hydrogen atom, and ^one of R ¹ and R ² is a hydrogen atom in that a compound that can damage the layer is less likely to be formed when the metal oxide-containing layer is formed. Or it is a linear alkyl group which does not have a substituent, and it is preferable that the other is a hydrogen atom. Specifically, acrylic acid, crotonic acid, isocrotonic acid, 2-pentenoic acid, 2-hexenoic acid, 2-heptenoic acid, 2-octenoic acid, 2-nonenoic acid, 2-decenoic acid, 2-undecenoic acid, or 2-dodecenoic acid is mentioned. Among these, acrylic acid in which R ¹ , R ² and R ³ are all hydrogen atoms is particularly preferable.

  Further, as described later, the α, β-unsaturated carboxylic acid according to the present invention has a boiling point in order to bias the reversible reaction between carboxylic acid metal chloride and hydrolysis accompanied by dehydration toward the latter hydrolysis side. An α, β-unsaturated carboxylic acid having a boiling point of less than 300 ° C. is preferred, an α, β-unsaturated carboxylic acid having a boiling point of 250 ° C. or less is more preferred, and an α, β-unsaturated carboxylic acid having a boiling point of 200 ° C. or less is more preferred. . The lower limit of the boiling point is not less than the boiling point (139 ° C.) of acrylic acid, which is the simplest and smallest α, β-unsaturated carboxylic acid having one carbon-carbon double bond (C═C) and one carboxyl group. is there.

  In addition, a metal oxide-containing layer can be formed using the metal oxide-containing layer forming composition according to the present invention, but an unreacted product of an unsaturated carboxylic acid metal salt is formed. The number of carbon atoms constituting the unsaturated carboxylic acid is 12 or less in order to facilitate the reaction from the unsaturated carboxylic acid metal salt to the metal oxide with less energy and not much remaining in the containing layer. More preferably, it is 6 or less, More preferably, it is 4 or less. On the other hand, the carbon number of the α, β-unsaturated carboxylic acid according to the present invention is 3 or more derived from acrylic acid. Specifically, acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, isocrotonic acid, angelic acid, tiglic acid, 2-pentenoic acid, 2-hexenoic acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid , Monomethyl fumarate, monoethyl fumarate, monomethyl maleate, monoethyl maleate, monomethyl itaconate, monomethyl citraconic acid, monoethyl citraconic acid, or monomethyl mesaconic acid. Of these, acrylic acid, which is the simplest and smallest α, β-unsaturated carboxylic acid having one carbon-carbon double bond (C═C) and one carboxyl group, is particularly preferred.

Note that, as described above, one molecule of unsaturated carboxylic acid metal salt is composed of m unsaturated carboxylic acids, but the m unsaturated carboxylic acids may be the same or different. May be. That is, m CR ¹ R ² ═CR ³ —COO ⁻ constituting the unsaturated carboxylic acid metal salt may be the same or different. Moreover, the composition for forming a metal oxide-containing layer according to the present invention may contain two or more unsaturated carboxylic acid metal salts. In this case, as long as the unsaturated carboxylic acid metal salt represented by the formula (I) is included, other unsaturated carboxylic acid metal salts may be included as long as the effects of the present invention are not impaired. .

  The content of the unsaturated carboxylic acid metal salt in the metal oxide-containing layer forming composition is not particularly limited, but is usually 0.1 mass relative to the total mass of the metal oxide-containing layer forming composition. % Or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, on the other hand, preferably 99.9% by mass or less, more preferably 50% by mass or less, and 20% by mass. It is particularly preferred that The content of the unsaturated carboxylic acid metal salt in the composition for forming a metal oxide-containing layer being within the above range means that the composition for forming a metal oxide-containing layer can be uniformly applied, and is uniform. This is preferable in that a metal oxide-containing layer can be obtained.

  In the metal oxide-containing layer forming composition, the unsaturated carboxylic acid metal salt may be present alone, or the metal oxide-containing layer forming composition contains a solvent as described below. In this case, the unsaturated carboxylic acid metal salt may form a complex with the solvent, or may form a multimer.

<1.1.1. Synthesis of unsaturated carboxylic acid metal salt>
The unsaturated carboxylic acid metal salt according to the present invention can be synthesized, for example, by a reaction between a metal compound and an unsaturated carboxylic acid, as described in publicly known literature (JP 2010-001395 A). . The metal compound used for the reaction is not particularly limited, and examples thereof include metal oxides, metal hydroxides, and metal acetates. Among them, it is preferable to synthesize an unsaturated carboxylic acid metal salt by using a dehydration reaction between an unsaturated carboxylic acid and a metal oxide or metal hydroxide in that the by-product is harmless water. It is more preferable to use a metal oxide as the compound. In view of ease of synthesis, it is also preferable to synthesize an unsaturated carboxylic acid metal salt by ion exchange between a carboxylic acid metal salt such as an acetic acid metal salt and an unsaturated carboxylic acid.

  There is no special restriction | limiting as a metal oxide, The oxide containing the desired metal of the metal oxide containing layer finally formed is mentioned. Examples thereof include scandium oxide, titanium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, indium oxide, gallium oxide, aluminum oxide, tin oxide, and lead oxide.

  The metal compound used for the reaction may be in a powder state or dispersed in a solvent. When the metal compound is in a powder state, the average primary particle size can be measured with a dynamic light scattering particle size measuring device, a transmission electron microscope (TEM), or the like. If it can be used, there is no particular limitation. Examples of powdered metal oxides include Nanozinc 60 (Honjo Chemical Co., Zinc Oxide), Nanozinc 100 (Honjo Chemical Co., Zinc Oxide), FINEX (registered trademark) -30 (Saga Chemical Industry Co., Ltd., Zinc oxide), ZINCOX SUPER F-2 (manufactured by Hakusui Tech Co., Ltd., zinc oxide) and the like. Examples of dispersed metal oxides include zinc oxide dispersions (catalog numbers 72085, 721107, etc.) manufactured by Aldrich.

  The metal compound used for the reaction may not be surface-treated, but may be surface-treated with a surface treatment agent. The surface treatment agent is not particularly limited as long as an unsaturated carboxylic acid metal salt is obtained, but a polysiloxane compound such as methylhydrogenpolysiloxane, polymethoxysilane, dimethylpolysiloxane, dimethicone PEG-7 succinate, and the like. Salts thereof; organosilicon compounds such as methyldimethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-carboxypropyltrimethyltrimethoxysilane, formic acid, acetic acid, lauric acid, Carboxylic acid compounds such as stearic acid and 6-hydroxyhexanoic acid; organic phosphorus compounds such as lauryl ether phosphoric acid and trioctylphosphine; dimethylamine, tributylamine, trimethylamine, cyclohexylamine, ethylene Amine compounds such as amines; polyimines, polyesters, polyamides, polyurethanes, binder resins such as poly urea. As a surface treating agent, only 1 type may be used or 2 or more types may be used together.

  When the metal compound used in the reaction is dispersed in the solvent, the solvent used is not particularly limited as long as the unsaturated carboxylic acid metal salt is obtained. For example, water; hexane, heptane, octane, isooctane, nonane, decane. Aliphatic hydrocarbons such as toluene, xylene, chlorobenzene, orthodichlorobenzene, etc .; methanol, ethanol, isopropanol, 2-methoxyethanol, 2-butoxyethanol, ethylene glycol, propylene glycol monomethyl ether (PGME) Alcohols such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone and N-methylpyrrolidone (NMP); esters such as ethyl acetate, butyl acetate and methyl lactate; chloroform, methylene chloride, dichloro Halogen hydrocarbons such as tan, trichloroethane, trichloroethylene; ethers such as propylene glycol monomethyl ether acetate (PGMEA), ethyl ether, tetrahydrofuran, dioxane; N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA Amides; and the like; and sulfoxides such as dimethyl sulfoxide (DMSO). Among them, water; alcohols such as methanol, ethanol, isopropanol, 2-methoxyethanol, 2-butoxyethanol, ethylene glycol, propylene glycol monomethyl ether (PGME); acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, N- Ketones such as methyl pyrrolidone (NMP); ethers such as propylene glycol monomethyl ether acetate (PGMEA), ethyl ether, tetrahydrofuran, dioxane, N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), etc. Amides; sulfoxides such as dimethyl sulfoxide (DMSO). More preferred are water; alcohols such as methanol, ethanol, isopropanol, 2-methoxyethanol, 2-butoxyethanol, ethylene glycol, propylene glycol monomethyl ether (PGME). As a solvent, only 1 type may be used and 2 or more types may be used together by arbitrary combinations and a ratio. Moreover, if the unsaturated carboxylic acid metal salt is obtained, there will be no restriction | limiting in particular in the boiling point of a solvent.

<1.2. Polyvinyl acetal resin>
The composition for forming a metal oxide-containing layer according to the present invention contains a polyvinyl acetal resin.

  In this invention, it is thought that the physical characteristic of the metal oxide content layer obtained improves by containing a polyvinyl acetal resin in a metal oxide composition. The reason for this is that, as described later in the present invention, a metal oxide-containing layer can be formed by generating a metal oxide from an unsaturated carboxylic acid metal salt represented by the above formula (I). It is considered that the mechanical strength of the obtained metal oxide-containing layer is improved because the acetal resin can be bonded to an adjacent layer at a stage where the particle size of the generated metal oxide is small. Moreover, since the metal oxides are bonded to each other by the polyvinyl acetal resin when the metal oxide having a small particle size is generated, the metal oxide constituting the metal oxide-containing layer has a uniform particle size. And are strongly bonded to each other. Therefore, it is considered that the mechanical strength such as bending rigidity and film hardness of the entire metal oxide-containing layer obtained is improved.

The polyvinyl acetal resin according to the present invention has a structural unit represented by the following formula (II).

In formula (II), R ^{4 to} R ⁹ each independently represent a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent. .

  The halogen atom is not particularly limited, but is preferably a highly stable fluorine atom.

  Examples of the alkyl group include a linear alkyl group, a branched alkyl group, and a cycloalkyl group. Among these, the alkyl group is not particularly limited, but is preferably a linear alkyl group having 1 to 3 carbon atoms. Specific examples include a methyl group, an ethyl group, and an n-propyl group.

  The aryl group preferably has 6 to 8 carbon atoms. Specifically, a phenyl group or a tosyl group is mentioned.

  The substituent that the alkyl group may have is not particularly limited, and examples thereof include an aryl group. Moreover, the substituent which the aryl group may have is not particularly limited, and examples thereof include an alkyl group.

Among these, in order to suppress the three-dimensional structure, R ^{4 to} R ⁹ are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ^{4 to} R ⁹ are each a hydrogen atom. Particularly preferred.

In formula (II), R ¹⁰ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. Examples of these groups include the same groups as the alkyl groups optionally having substituents mentioned in R ^{4 to} R ⁹ or the aryl groups optionally having substituents. Among these, in order to suppress the three-dimensional structure, R ¹⁰ is preferably an alkyl group having 1 to 3 carbon atoms.

  In addition, unless the effect of this invention is impaired, the polyvinyl acetal resin may have another structural unit, and there is no special restriction | limiting in another structural unit. For example, in addition to the vinyl acetal unit represented by the following formula (3A), the polyvinyl acetal resin includes a vinyl alcohol unit represented by the following formula (3B), a vinyl acetate unit represented by the following formula (3C), You may have.

Wherein (3A), R ⁴ ~R ¹⁰ is synonymous with R ⁴ to R ¹⁰ in the formula (II).

In formula (3B), R ^{b1 to} R ^b3 each independently represent a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent.

Examples of the alkyl group which may have a substituent and the aryl group which may have a substituent include the same groups as those described for R ^{4 to} R ¹⁰ in formula (II), and are preferable. The group is the same.

In formula (3C), R ^{c1 to} R ^c3 each independently represent a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent.

Examples of the alkyl group which may have a substituent and the aryl group which may have a substituent include the same groups as those described for R ^{4 to} R ¹⁰ in formula (II), and are preferable. The group is the same.

  In formulas (3A) to (3C), n, l and k represent the molar ratio of each unit in the polyvinyl acetal resin.

  The molar ratio (n) of the acetal unit represented by the formula (3A) with respect to all structural units is usually 10 mol% or more, preferably 30 mol% or more, and more preferably 50 mol% or more. On the other hand, the upper limit is usually 90 mol% or less, preferably 80 mol% or less, and more preferably 70 mol% or less. By being within the above range, formation of a metal oxide-containing layer having high electrical characteristics and appropriate film hardness can be expected.

  The molar ratio (l) of the vinyl alcohol unit represented by the formula (3B) with respect to all the structural units is usually 10 mol% or more, preferably 15 mol% or more, and more preferably 20 mol% or more. On the other hand, the upper limit is usually 50 mol% or less, preferably 45 mol% or less, and more preferably 40 mol% or less. By being within the above range, formation of a metal oxide-containing layer having high electrical characteristics and appropriate film hardness can be expected.

  The molar ratio (k) of the vinyl acetate unit represented by the formula (3C) with respect to all the structural units is usually 0.1 mol% or more, preferably 0.5 mol% or more, and more preferably 1 mol% or more. On the other hand, the upper limit is usually 30 mol% or less, preferably 25 mol% or less, and more preferably 20 mol% or less. By being within the above range, formation of a metal oxide-containing layer having high electrical characteristics and appropriate film hardness can be expected.

  The molecular weight of the polyvinyl acetal resin according to the present invention is arbitrary as long as the effects of the present invention are not significantly impaired, but is a value of polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC), usually 5000. It is above, Preferably it is 10,000 or more, More preferably, it is 20,000 or more. On the other hand, the upper limit is usually 1,000,000 or more, preferably 500,000 or less, more preferably 250,000 or less. By being within the above range, formation of a metal oxide-containing layer having high electrical characteristics and appropriate film hardness can be expected.

  Further, the number average molecular weight (Mn) of the polyvinyl acetal resin of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired, but is a value obtained by dividing Mw by Mn (Mw / Mn), usually 1.5 or more. , Preferably 2 or more, more preferably 2.5 or more. On the other hand, the upper limit is usually 5 or less, preferably 4.5 or less, more preferably 4 or less. By being within the above range, formation of a metal oxide-containing layer having high electrical characteristics and appropriate film hardness can be expected. Mn can also be measured by the same method as Mw.

  The polyvinyl acetal resin has a viscosity of 5% by mass of toluene / ethanol (1/1 by mass) as a solvent, usually 10 mPa · s or more, preferably 15 mPa · s or more, more preferably 20 mPa · s or more. It is. On the other hand, the upper limit is usually 300 mPa · s or less, preferably 250 mPa · s or less, more preferably 200 mPa · s. By being within the above range, a uniform metal oxide-containing layer can be easily formed. The viscosity can be measured using a RE85 viscometer (manufactured by Toki Sangyo Co., Ltd.).

  There are no particular restrictions on the method for producing the polyvinyl acetal resin, but usually an acetalization reaction between polyvinyl alcohol and an aldehyde is carried out in a solvent containing an acid catalyst, and a neutralizing agent for the acid catalyst is mixed in the reaction system. Then, the reaction is stopped, and then, if necessary, a polyvinyl acetal resin can be produced through steps such as washing with water and drying.

  Hereinafter, although an example of the manufacturing method of the polyvinyl acetal of this invention is demonstrated more concretely, the manufacturing method of the polyvinyl acetal of this invention is not limited to the following method.

  The aldehyde is not particularly limited, but an aldehyde having 1 to 10 carbon atoms is preferable. Specific examples include formaldehyde, acetaldehyde, propanal, butanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal, decanal, acrolein, benzaldehyde, cinnamaldehyde, perillaldehyde, and vanillin. Moreover, these aldehyde compounds may have a substituent, for example, the monovalent organic group mentioned by the above-mentioned (alpha), (beta) -unsaturated carboxylic acid metal salt is mentioned. In addition, when it has a substituent, let the preferable carbon number mentioned above be a carbon number including a substituent. Of these, acetaldehyde, propanal, butanal, butanal, and pentanal are preferable, and acetaldehyde, propanal, and n-butanal are more preferable. The reason why acetaldehyde, propanal, or n-butanal is more preferable is that the corresponding metal oxide-containing layer containing a polyvinyl acetal resin can have high electrical characteristics and appropriate film hardness. Moreover, an aldehyde may be used independently, or 2 or more types may be used in arbitrary ratios and combinations.

  The acid catalyst for the acetalization reaction is not particularly limited as long as the effect of the present invention is not significantly impaired. For example, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, benzenesulfonic acid, toluenesulfonic acid, strong acidic ion exchange Examples include organic acids such as resins. Of these, inorganic acids are preferable, and hydrochloric acid is more preferable. Moreover, an acid catalyst may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

  The solvent for the acetalization reaction is not particularly limited as long as the effects of the present invention are not significantly impaired, and examples thereof include organic solvents such as alcohols, esters, ketones, and aromatics, and water. Moreover, a solvent may be used individually by 1 type and may use 2 or more types by arbitrary ratios and combinations.

  As a specific acetalization reaction method, for example, a solvent method in which polyvinyl alcohol is dispersed in an organic solvent to be acetalized to obtain a polyvinyl acetal resin as a solution, and an aqueous polyvinyl alcohol is acetalized to slurry the polyvinyl acetal resin. An aqueous medium method obtained in the form of a solution, and a uniform method of obtaining a polyvinyl acetal resin in a solution state while mixing the organic solvent during the reaction for acetalizing the aqueous polyvinyl alcohol and maintaining the liquid state. Among these, the water medium method is preferably used from the viewpoint of environmental burden due to the use of the organic solvent. That is, the polyvinyl acetal resin according to the present invention is preferably obtained by performing an acetalization reaction of polyvinyl alcohol in an aqueous solvent.

  The neutralizing agent for the acid catalyst is not particularly limited as long as the effects of the present invention are not significantly impaired. For example, inorganic bases such as sodium hydroxide and potassium hydroxide, amine compounds, ethylene oxide, propylene oxide, butylene oxide, Examples include epoxides such as styrene oxide, among which epoxides having no residual salts are preferable. Moreover, a neutralizing agent may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

  The amount of the neutralizing agent is not limited as long as the effects of the present invention are not significantly impaired, but usually an amount that can neutralize the acid catalyst and stop the reaction is used.

  Specific examples of the polyvinyl acetal resin include S-LEC B series (Sekisui Chemical Co., Ltd., polyvinyl butyral), S-LEC K series (Sekisui Chemical Co., Ltd., polyvinyl acetoacetal), Mobital series (Kuraray Co., polyvinyl butyral), A pioloform (made by Kuraray Co., Ltd., polyvinyl butyral) can be mentioned.

  The ratio of the polyvinyl acetal resin to the total mass of the unsaturated carboxylic acid metal salt represented by the above formula (I) and the polyvinyl acetal resin in the metal oxide-containing layer forming composition is not particularly limited. In order to appropriately control the wettability with the layer to be formed and improve the coating property, it is preferably 0.4% by mass or more, more preferably 1.0% by mass or more, and 2.0% by mass. On the other hand, it is particularly preferably 40% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less.

  The wettability can be evaluated by the contact angle in addition to the actual application to the substrate. It can be measured with a normal contact angle meter (for example, DM-501 manufactured by Kyowa Interface Science Co., Ltd.). The contact angle of the metal oxide-containing layer forming composition according to the present invention is usually 45 ° or less, preferably 30 ° or less, and more preferably 15 ° or less with respect to the base material on which the silver foil is laminated. Further, spreading over the entire surface of the base material means that the contact angle is not detected, and therefore it is particularly preferably not detected. By being 45 degrees or less, the composition for forming a metal oxide-containing layer according to the present invention can be applied on any substrate.

  In addition, a polyvinyl acetal resin may be used independently and may use 2 or more types by arbitrary ratios and combinations.

<1.3. Other compounds>
The composition for forming a metal oxide-containing layer according to the present invention may contain another compound other than the above as long as the effects of the present invention are not impaired. For example, the metal oxide-containing layer forming composition according to the present invention may contain a solvent.

  Although it does not specifically limit as a solvent, For example, Water; Aliphatic hydrocarbons, such as hexane, heptane, octane, isooctane, nonane, decane; Aromatic hydrocarbons, such as toluene, xylene, chlorobenzene, orthodichlorobenzene; Methanol , Ethanol, isopropanol, 2-methoxyethanol, 2-butoxyethanol, ethylene glycol, propylene glycol monomethyl ether (PGME) and other alcohols; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, ketones such as N-methylpyrrolidone (NMP) Esters such as ethyl acetate, butyl acetate and methyl lactate; Halogen hydrocarbons such as chloroform, methylene chloride, dichloroethane, trichloroethane and trichloroethylene; Propylene glycol Ethers such as monomethyl ether acetate (PGMEA), ethyl ether, tetrahydrofuran and dioxane; Amides such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMA); Sulfoxides such as dimethyl sulfoxide (DMSO) Kind. Of these, water; aromatic hydrocarbons such as toluene, xylene, chlorobenzene and orthodichlorobenzene; methanol, ethanol, isopropanol, 2-methoxyethanol, 2-butoxyethanol, ethylene glycol, propylene glycol monomethyl ether (PGME) Alcohols such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone and N-methylpyrrolidone (NMP); ethers such as propylene glycol monomethyl ether acetate (PGMEA), ethyl ether, tetrahydrofuran and dioxane, N, N -Amides such as dimethylformamide (DMF) and N, N-dimethylacetamide (DMA); and sulfoxides such as dimethylsulfoxide (DMSO).More preferred are water; alcohols such as methanol, ethanol, isopropanol, 2-methoxyethanol, 2-butoxyethanol, ethylene glycol, propylene glycol monomethyl ether (PGME).

  The reason why alcohols are preferable is that α, β-unsaturated carboxylic acid metal salt and polyvinyl acetal resin have high solubility in alcohols, and can stably maintain a solution state without being decomposed in alcohols. Is mentioned.

In addition, only 1 type may be used for a solvent and 2 or more types of arbitrary solvents may be used. In addition, the boiling point of the solvent is not particularly limited because the solvent may remain in the resulting metal oxide-containing layer as long as the electrical characteristics are not significantly impaired.

  Moreover, as another compound other than the solvent, for example, it is possible to suppress the formation of dents in the obtained metal oxide-containing layer due to the attachment of fine bubbles or foreign matters, or to prevent the occurrence of uneven coating in the drying process. For the purpose, a surfactant may be included.

The surfactant is not particularly limited, and known surfactants (cationic surfactants, anionic surfactants, nonionic surfactants) can be used. Of these, a silicon-based surfactant, a fluorine-based surfactant, or an acetylene glycol-based surfactant is preferable. Specific examples of the surfactant include Triton X100 (manufactured by Dow Chemical Co.) as a nonionic surfactant, Zonyl FS300 (manufactured by DuPont) as a fluorosurfactant, BYK-310 as a silicon surfactant, BYK-320, BYK-345 (manufactured by Big Chemie), and acetylene glycol surfactants include Surfinol 104, Surfynol 465 (manufactured by Air Products), Olphin EXP4036, or Olphine EXP4200 (manufactured by Nissin Chemical Industry Co., Ltd.) Is mentioned.

  The polyvinyl acetal resin according to the present invention has the effect of suppressing the occurrence of dents in the resulting metal oxide-containing layer and preventing the occurrence of coating unevenness in the drying process. The composition need not contain.

  The composition for forming a metal oxide-containing layer is preferably stable for 2 weeks or more, and more preferably stable for 1 month or more. The composition for forming a metal oxide-containing layer according to the present invention will be described later. As can be seen from the results of the examples, the stability is extremely high. Therefore, the composition for forming a metal oxide-containing layer according to the present invention enables large-scale synthesis and long-term storage of the ink, and can reduce the manufacturing cost. Note that the stability of the ink can be evaluated by the formation of a precipitate, a change in viscosity, and the like.

  The formation of the precipitate can be judged visually or with a dynamic light scattering particle size measuring device. In addition, the viscosity of the metal oxide-containing layer forming composition according to the present invention is measured using a rotational viscometer method ("Physical Chemistry Experiment" (Ginya Adachi, Yasutaka Ishii, Hen Yoshida, edited by Kagaku Dojin (1993) In particular, it can be measured using a RE85 viscometer (manufactured by Toki Sangyo Co., Ltd.).

<2. Method for forming metal oxide-containing layer>
The metal oxide-containing layer is obtained by applying the metal oxide-containing layer forming composition according to the present invention to a desired support for forming the metal oxide-containing layer (application step of the metal oxide-containing layer forming composition). ), And then heat treatment (heat treatment step) (hereinafter may be referred to as a method for forming a metal oxide-containing layer according to the present invention). The method for forming a metal oxide-containing layer according to the present invention can form a metal oxide-containing layer having high uniformity at a low temperature as compared with a sol-gel method or a dispersion method.

<2.1. Application Step of Metal Oxide Containing Layer Forming Composition>
Any method can be used as a coating method of the metal oxide-containing layer forming composition. Examples thereof include spin coating, gravure coating, kiss coating, roll brushing, spray coating, air knife coating, wire barber coating, pipe doctor method, impregnation / coating method, and curtain coating method. Moreover, only 1 type of method may be used as an application | coating method, and it can also be used in combination of 2 or more types.

<2.2. Heat treatment process>
In the present invention, after the application of the metal oxide-containing layer forming composition, heat treatment is performed to form a metal oxide-containing layer by performing a metal oxide formation reaction using an unsaturated carboxylic acid metal salt as a raw material. be able to.

  Although the detailed mechanism by which the metal oxide-containing layer forming composition can be heat-treated to produce the metal oxide is not known, as shown in the formula (III), the unsaturated carboxylic acid metal The salt is hydrolyzed to a metal hydroxide by reacting with the moisture in the outside air, and finally converted into a metal oxide, and as shown in (IV), the unsaturated carboxylic acid metal salt is formed. It is considered that a metal oxide is obtained by a route or the like in which a pure metal is generated by thermal decomposition of a saturated carboxylic acid and is finally combined with oxygen in the outside air to change to a metal oxide.

  As described above, the production reaction can be performed by applying an external stimulus such as water or heat. In addition, in the production | generation reaction which concerns on this invention, since it seems that the hydrolysis of unsaturated carboxylic acid metal salt is a main reaction, it is thought that a production | generation reaction is accelerated | stimulated by performing heat processing.

  The temperature of the heat treatment is preferably less than 300 ° C., more preferably 250 ° C. or less, and particularly preferably 200 ° C. or less. It is preferable that the temperature is lower than 300 ° C. because it is a temperature that can be used in a manufacturing process using a flexible base material such as a roll-to-roll method.

  On the other hand, the lower limit is not particularly limited, but is usually 80 ° C. or higher, preferably 100 ° C. or higher. The reason why the temperature is preferably 100 ° C. or higher is that the temperature at which water changes to water vapor having a high degree of freedom is 100 ° C. or higher. Although the detailed mechanism of the metal oxide formation reaction is unknown, water vapor serves as a reactant in the hydrolysis reaction when the unsaturated carboxylic acid metal salt changes to a metal oxide, and in the thermal decomposition reaction described below. At least one of the functions as a reaction catalyst can be performed. For this reason, it is thought that the change from unsaturated carboxylic acid metal salt to metal oxide is promoted by the presence of water vapor, and the heat treatment time can be shortened.

  It is possible to use a flexible base material that uses a resin base material such as polyethylene terephthalate, a composite material that imparts insulation to a metal foil such as copper, etc. to perform heat treatment at a lower temperature. It is advantageous. In particular, in flexible electronic devices, the construction of a process capable of producing a high-density and high-performance metal oxide thin film at a low temperature is cited as an issue to be solved immediately (Applied Physics, 2012, 81, 728.). . In this regard, according to the method for producing a metal oxide-containing layer according to the present invention, a high-performance metal oxide-containing layer can be produced at a low temperature.

  The heating time is not particularly limited as long as the production reaction proceeds, but is usually 30 seconds or longer, preferably 1 minute or longer, more preferably 2 minutes or longer, and further preferably 3 minutes or longer. On the other hand, it is usually 180 minutes or less, preferably 60 minutes or less, more preferably 30 minutes or less, and even more preferably 15 minutes or less. It is preferable that the heating time be in the above range in that the production reaction can proceed sufficiently and the production reaction can proceed smoothly even in a practical production process such as a roll-to-roll method.

  If the heating temperature is lower than 300 ° C. and the temperature is high, the production reaction from the unsaturated carboxylic acid metal salt to the metal oxide tends to proceed. In addition, a metal oxide-containing layer having high peel strength and excellent characteristics can be produced. On the other hand, even if the heating temperature is low, by increasing the heating time, it is possible to produce a metal oxide-containing layer having high hardness and high peel strength and excellent characteristics. Therefore, what is necessary is just to select a heating time and heating temperature suitably by the base material etc. to be used.

  In the heat treatment step, it is not necessary for all of the unsaturated carboxylic acid metal salt contained in the metal oxide-containing layer forming composition to be converted into a metal oxide. Specifically, among the unsaturated carboxylic acid metal salt contained in the metal oxide-containing layer forming composition, usually 60% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more. What is necessary is just to change to a metal oxide.

  In addition, the ratio of what changed into the metal oxide among unsaturated carboxylic acid metal salts can be quantified by infrared spectroscopy (IR) from the formed metal oxide content layer. Further, the ratio of the metal oxide in the product can be quantified by a spectrophotometer or X-ray photoelectron spectroscopy (XPS or ESCA).

  Moreover, although the detailed mechanism of the metal oxide formation reaction is not known, the environment of the outside air such as oxygen concentration and moisture concentration (humidity) may also affect the metal oxide-containing layer.

  Specifically, the oxygen concentration in the atmosphere during the heat treatment is usually 50% by volume or less, preferably 30% by volume or less, more preferably 25% by volume or less. When the oxygen concentration is within this range, a uniform metal oxide-containing layer having better characteristics can be obtained. When the oxygen concentration is 50% by volume or less, by-product of unstable substances such as peroxides due to excessive oxygen can be prevented.

  On the other hand, the moisture concentration in the atmosphere at the time of heat treatment has a great influence on the formation of metal oxides from unsaturated carboxylic acid metal salts. This is because water is important as a reactive substance in the hydrolysis reaction. The specific moisture concentration is usually over 1%, preferably 5% or more, more preferably 10% or more, and further preferably 30% or more as the humidity at 25 ° C. On the other hand, usually 90% or less, Preferably it is 85% or less, More preferably, it is 80% or less. When the moisture concentration is within this range, a uniform metal oxide-containing layer having better characteristics can be obtained. For example, when the humidity exceeds 1%, the production of the metal oxide from the unsaturated carboxylic acid metal salt can be stably performed at a low temperature.

  In addition, the inclusion of the polyvinyl acetal resin in the composition for forming a metal oxide-containing layer according to the present invention can prevent moisture from adhering to a substrate having a humidity range of 30% to 90%. The metal oxide-containing layer forming composition containing a saturated carboxylic acid metal salt can be uniformly applied. This is because the hydrophilicity due to the hydroxyl group contained in the polyvinyl acetal resin works effectively and wettability is improved. In this specification, the humidity at 25 ° C. refers to the relative humidity when the atmosphere is adjusted to 25 ° C.

<3. Metal oxide-containing layer>
The metal oxide-containing layer obtained by the method for forming a metal oxide-containing layer according to the present invention (hereinafter sometimes referred to as a metal oxide-containing layer according to the present invention) constitutes an electronic device as will be described later. It can be used as a layer, for example, a buffer layer of a photoelectric conversion element.

  The metal oxide-containing layer according to the present invention includes a scandium oxide-containing layer, a titanium oxide-containing layer, a vanadium oxide-containing layer, a chromium oxide-containing layer, a manganese oxide-containing layer, an iron oxide-containing layer, a cobalt oxide-containing layer, and a nickel oxide-containing layer. Examples include a layer, a copper oxide-containing layer, a zinc oxide-containing layer, an indium oxide-containing layer, a gallium oxide-containing layer, an aluminum oxide-containing layer, a tin oxide-containing layer, or a lead oxide-containing layer. Among these, a titanium oxide-containing layer, a nickel oxide-containing layer, a copper oxide-containing layer, a zinc oxide-containing layer, an indium oxide-containing layer, or a tin oxide-containing layer is more preferable, and is generated from the unsaturated carboxylic acid metal salt according to the present invention. A zinc oxide-containing layer is particularly preferred because of its ease of use.

  The metal oxide containing layer according to the present invention contains a polyvinyl acetal resin. The polyvinyl acetal resin is not particularly limited, and <1-2. Polyvinyl acetal resin>.

  The content of the metal oxide in the metal oxide-containing layer is usually 10% by mass or more, preferably 20% by mass or more, more preferably 40% by mass or more, and still more preferably based on the total mass of the metal oxide-containing layer. It is preferably 60% by mass or more, particularly preferably 80% by mass or more, and on the other hand 99% by mass or less. By being in this range, a uniform metal oxide-containing layer having better characteristics can be obtained.

  The content of the polyvinyl acetal resin in the metal oxide-containing layer is not particularly limited. However, in order to achieve both electrical characteristics and appropriate film hardness, 1 mass with respect to the total mass of the metal oxide-containing layer. % Or more, more preferably 2.5% by mass or more, particularly preferably 5% by mass or more, and on the other hand, preferably 60% by mass or less, and 40% by mass or less. More preferably, it is particularly preferably 20% by mass or less.

  The presence of the polyvinyl acetal resin in the metal oxide-containing layer improves the electrical characteristics of the electronic device. The reason for this is that if a polyvinyl acetal resin is present in the metal oxide-containing layer, it is considered that the conductive path of individual charges is hindered by the insulation of the polyvinyl acetal resin. This is presumably because the crystallinity of the oxide-containing layer is improved and the adhesion between the metal oxides is improved, resulting in an increase in the charge conduction path. In general, in photoelectric conversion elements and the like, photodoping can improve charge density and electrical characteristics, but the metal oxide-containing layer according to the present invention has a high charge density. Therefore, improvement of the photodoping effect can be expected.

  Moreover, it is thought that the color of an electronic device can be improved by the presence of the polyvinyl acetal resin in the metal oxide-containing layer according to the present invention. Specifically, the metal oxide-containing layer according to the present invention has high film uniformity and high crystallinity because the particle size of the metal oxide is uniform due to the presence of the polyvinyl acetal resin. Therefore, it is considered that scattering of light transmitted through the metal oxide-containing layer can be suppressed, and as a result, an electronic device having high design with improved color can be provided. Therefore, the metal oxide-containing layer according to the present invention is preferably applied to a see-through type electronic device that requires high design properties, and particularly preferably used for a photoelectric conversion element described later. By using for a photoelectric conversion element, it can be set as the photoelectric conversion element which made high conversion efficiency and high designability compatible, without interfering with indoor lighting. Specifically, the metal oxide-containing layer according to the present invention is considered to be particularly effective in a photoelectric conversion element having a visible light transmittance of 15% or more and 90% or less. Among these, the visible light transmittance of the photoelectric conversion element is preferably 20% or more, more preferably 25% or more, particularly preferably 30% or more, and on the other hand, 80% or less. Preferably, it is 70% or less, more preferably 60% or less. The visible light transmittance can be measured with a spectrophotometer U-4100 (manufactured by Hitachi High-Tech).

  The metal oxide-containing layer may be doped with impurities. Examples of the impurity include a doping material described later or a compound derived from the unsaturated carboxylic acid metal salt according to the present invention.

  In addition, the metal oxide-containing layer according to the present invention may contain a compound other than the above. Examples thereof include compounds derived from surfactants, decomposed products of unsaturated carboxylic acids constituting unsaturated carboxylic acid metal salts represented by formula (I), and polymers thereof.

  Moreover, it is preferable that the metal oxide containing layer which concerns on this invention does not have a specific crystal orientation extremely. In the case of a thin film, it is usually not a single crystal but a polycrystal. Taking zinc oxide as an example, zinc oxide tends to have a wurtzite type crystal structure, and a polycrystal having a strong c-axis orientation is likely to be formed by a dry film-forming method such as sputtering or an electrolysis method. However, a polycrystal having a strong c-axis orientation has a high electron mobility, but has a problem that durability against an external environment such as heat and humidity is weak. In that respect, if it is a polycrystal having no specific crystal orientation, durability against the environment of the outside air may be improved.

  In particular, in the genus oxide-containing layer according to the present invention, when a metal oxide is produced from an unsaturated carboxylic acid metal salt, the presence of the polyvinyl acetal resin does not have a specific crystal orientation. Since the formation of polycrystals can be expected, good durability can be expected.

  In particular, when the metal oxide-containing layer is a zinc oxide-containing layer, the half width of the 2θ peak on the (002) plane is 1 ° or more in the X-ray diffraction (XRD) method (out of plane measurement) of the zinc oxide-containing layer. It is preferably 1.1 ° or more, more preferably 1.2 ° or more, while it is preferably 5 ° or less, more preferably 4 ° or less. It is particularly preferable that the angle is 5 ° or less. Within this range, high electron mobility and durability against the environment of the outside air can be compatible.

  In addition, when an electronic device is manufactured industrially, for example, when a roll-to-roll process is used, since the film formation surface may be damaged particularly during winding, the layer has an appropriate hardness. It is preferable to have. If the layer is physically damaged, the desired properties may not be achieved. The hardness of the metal oxide-containing layer according to the present invention can be examined by a pencil scratch hardness test (for example, JIS K5600-5-4 (1999)).

  Examples of the pencil scratch hardness tester include a continuous load type scratch strength tester Heidon Type 18 manufactured by Shinto Kagaku Co., Ltd. The lower limit of the measured pencil hardness is preferably 2H or more, more preferably 3H or more. On the other hand, the upper limit is preferably 8H or less, more preferably 6H or less. It is preferable that it is in the above-mentioned range since hardness suitable for an industrial production method using a roll-to-roll process or the like and desirable characteristics can be achieved at the same time.

  Hereinafter, the electronic device according to the present invention will be described in detail.

<4. Electronic device>
The metal oxide-containing layer according to the present invention can be applied as a semiconductor layer of an electronic device. Note that in this specification, an electronic device is a device that has two or more electrodes and controls the current flowing between the electrodes and the voltage generated by electricity, light, magnetism, a chemical substance, or the like, or an applied voltage. It is a device that generates light, an electric field, and a magnetic field by electric current and current. For example, there are an element that controls current and voltage by applying voltage and current, an element that controls voltage and current by applying a magnetic field, and an element that controls voltage and current by applying a chemical substance. This control includes rectification, switching, amplification, or oscillation.

  Examples of electronic devices include resistors, rectifiers (diodes), switching elements (transistors, thyristors), amplifier elements (transistors), memory elements, chemical sensors, etc., or devices in which these elements are combined or integrated. It is done. In addition, a photodiode or a phototransistor that generates a photocurrent, an electroluminescent element that emits light by applying an electric field, and an optical element such as a photoelectric conversion element or a solar cell that generates an electromotive force by light can also be used.

  More specific examples of electronic devices are described in S.A. M.M. Examples include those described in Sze, Physics of Semiconductor Devices, 2nd Edition (Wiley Interscience 1981).

  Especially, as an electronic device, a field effect transistor, an electroluminescent element, a photoelectric conversion element, and a solar cell are suitable as an example which produces a higher electrical characteristic. These are electronic devices that exhibit performance by arranging pn junctions in the light traveling direction, and the characteristics of the metal oxide-containing layer according to the present invention work preferentially.

  Hereinafter, a field effect transistor element (FET), an electroluminescence element (LED), a photoelectric conversion element, and a solar cell will be described in detail as suitable examples of the electronic device according to the present invention.

<5. Field Effect Transistor (FET)>
A field effect transistor (FET) element according to the present invention includes a semiconductor layer, an insulator layer, a source electrode, a gate electrode, and a gate electrode. The FET element according to the present invention is characterized by having the metal oxide-containing layer according to the present invention.

  Hereinafter, the FET element according to the present invention will be described in detail. FIG. 1 is a diagram schematically showing an example of the structure of an FET element according to the present invention. As shown in FIG. 1A, the FET element has a semiconductor layer 51, an insulator layer 52, a source electrode 53, a drain electrode 54, and a gate electrode 55 on a base material 56. Note that the structure of the FET element is not limited to that shown in FIG. 1, and for example, the structure shown in FIGS. 1B to 1D may be used.

<5.1. Electrode>
In the FET element according to the present invention, each of the source electrode 53, the drain electrode 54, and the gate electrode 55 includes, for example, platinum, gold, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, sodium, etc. Metal: Conductive oxide such as indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), indium tin oxide (ITO); conductive polymer such as polyaniline, polypyrrole, polythiophene, polyacetylene; hydrochloric acid, sulfuric acid, Bronsted acids such as sulfonic acid, hexafluorophosphate ions (PF ₆ ⁻ ), Lewis acids such as arsenic pentafluoride (AsF ₅ ), iron chloride (FeCl ₃ ), halogen atoms such as iodine, sodium, potassium, etc. Addition of a dopant such as a metal atom to the conductive polymer as described above; carbon black , A conductive material of the composite materials of the conductive metal particles or the like are dispersed is used.

  The formation method of the source electrode 53, the drain electrode 54, and the gate electrode 55 is not particularly limited, and according to material characteristics, wet coating methods such as spin coating, blade coating, and spin coating, vapor deposition, and sputtering. Further, it may be formed by a known method such as a printing method such as screen printing or inkjet.

<5.2. Insulator layer>
Examples of the material used for the insulator layer 52 of the FET element according to the present invention include polymethyl methacrylate, polystyrene, polyvinyl phenol, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, epoxy resin, and phenol. Polymers such as resins and copolymers thereof; oxides such as silicon dioxide, aluminum oxide and titanium oxide; nitrides such as silicon nitride; ferroelectric oxides such as strontium titanate and barium titanate; and oxidation thereof And polymers in which particles such as oxides, nitrides, and ferroelectric oxides are dispersed.

  In general, the larger the capacitance of the insulating layer 52, the more advantageous is that the gate voltage can be driven at a lower voltage. This can be realized by using an insulating material having a large dielectric constant or by reducing the thickness of the insulator layer.

  The method for forming the insulator layer 52 is not particularly limited. For example, a wet coating method such as a spin coating method, a blade coating method, or a spin coating method, a vapor deposition method, a sputtering method, a printing method such as screen printing or inkjet, an aluminum It can be formed by a known method in accordance with material characteristics such as a method of forming an oxide film on a metal so as to form alumite.

<5.3. Base material>
The FET element according to the present invention is usually produced on a base material 56. The material of the base material 56 is not particularly limited as long as the effects of the present invention are not significantly impaired. Preferable examples of the material of the substrate 56 include inorganic materials such as quartz, glass, sapphire, and titania; flexible substrates. In the present invention, the flexible substrate is a substrate having a radius of curvature of usually 0.1 mm or more and 10,000 mm or less. In the case of producing a flexible electronic device, the radius of curvature is preferably 0.3 mm or more, more preferably 1 mm or more, in order to achieve both flexibility and characteristics as a support. It is preferably 3000 mm or less, and more preferably 1000 mm or less. The radius of curvature can be obtained with a confocal microscope (for example, a shape measurement laser microscope VK-X200 manufactured by Keyence Co., Ltd.) obtained by bending a base material that has been bent to a point where no damage such as distortion or cracking appears. Specific examples of the flexible substrate include, but are not limited to, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluororesin film, vinyl chloride. Or polyolefins such as polyethylene; organic materials such as cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene or epoxy resin; paper materials such as paper or synthetic paper; silver, copper, stainless steel, titanium Alternatively, a composite material such as a metal foil such as aluminum whose surface is coated or laminated in order to impart insulating properties can be used. In particular, the method for producing a metal oxide-containing layer according to the present invention is particularly effective when using a flexible substrate as described above.

  Furthermore, the characteristics of the FET can be improved by processing the substrate 56. This is because by adjusting the hydrophilicity / hydrophobicity of the base material 56, the film quality of the semiconductor layer 51 to be formed is improved, in particular, by improving the characteristics of the interface portion between the base material 53 and the semiconductor layer 51. Estimated. Such substrate treatment includes hydrophobization treatment using hexamethyldisilazane, cyclohexene, octadecyltrichlorosilane, etc., acid treatment using acids such as hydrochloric acid, sulfuric acid, and acetic acid, sodium hydroxide, potassium hydroxide, Alkaline treatment using calcium hydroxide and ammonia, ozone treatment, fluorination treatment, plasma treatment using oxygen, argon, etc., Langmuir Blodget film formation treatment, other insulator or semiconductor thin film formation treatment Can be mentioned.

<5.4. Semiconductor layer>
The semiconductor layer 51 of the FET element according to the present invention is obtained by forming a semiconductor film on a substrate directly or via another layer, and the metal oxide-containing layer according to the present invention is preferably used.

  The semiconductor layer 51 may have a stacked structure of a metal oxide-containing layer according to the present invention and a layer containing a different material or a different component from the metal oxide-containing layer.

  The film thickness of the semiconductor layer 51 is not particularly limited. For example, in the case of a lateral field effect transistor element, the element characteristics do not depend on the film thickness of the semiconductor layer 51 as long as the film thickness is equal to or greater than a predetermined film thickness. However, since the leakage current often increases when the film thickness becomes too thick, the film thickness of the semiconductor layer 51 is usually 0.5 nm or more, preferably 10 nm or more, and is usually 1 μm or less from the viewpoint of cost. Preferably, it is 200 nm or less.

<6. Electroluminescent device (LED)>
An electroluminescent element is a self-luminous element that utilizes the principle that a fluorescent substance emits light by recombination energy between holes injected from an anode and electrons injected from a cathode when an electric field is applied.

  Hereinafter, an electroluminescent element according to the present invention will be described with reference to the drawings. FIG. 2 is a cross-sectional view schematically showing one embodiment of the electroluminescent element according to the present invention. As shown in FIG. 2, the electroluminescent device 39 includes an anode 32, a hole injection layer 33, a hole transport layer 34, a light emitting layer 35, an electron transport layer 36, and an electron injection on a base material 31. A layer 37 and a cathode 38 are included. Note that the hole injection layer 33, the hole transport layer 34, the electron transport layer 38, and the electron injection layer 39 are not necessarily provided, and may be arbitrarily selected and provided.

<6.1. Substrate (31)>
The base material 31 serves as a support for the electroluminescent element 39, and the material thereof is not particularly limited as long as the effects of the present invention are not significantly impaired. Preferable examples of the material of the base material 31 include inorganic materials such as quartz, glass, sapphire, and titania; and flexible base materials. Specific examples of the flexible substrate include, but are not limited to, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluororesin film, vinyl chloride. Polyolefins such as polyethylene; organic materials (resin base materials) such as cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene, epoxy resin; paper materials such as paper or synthetic paper; silver, Examples of the composite material include a metal foil such as copper, stainless steel, titanium, and aluminum whose surface is coated or laminated in order to impart insulation.

  Among these, the method for producing a metal oxide-containing layer according to the present invention is particularly effective when used for a flexible substrate. For example, when a metal oxide-containing layer is produced by a conventional method, it is extremely difficult to use a resin substrate having a low glass transition temperature because a high-temperature process is required. On the other hand, the present invention can be applied to a resin substrate having a low glass transition temperature because the metal oxide-containing layer can be produced by a low-temperature process. In addition, even when a composite material in which the above-described metal foil is provided with an insulating property is used as a base material, since the film thickness is very small, when a metal oxide-containing layer is manufactured by a high-temperature process as in the past, The material will be distorted. Therefore, the present invention is extremely effective even when a composite material in which an insulating property is imparted to a metal foil is used as a base material. Furthermore, since a flexible base material can be used for the present invention as described above, it becomes possible to manufacture an electroluminescent device by a roll-to-roll method, and productivity is improved.

  When using a resin base material, it is necessary to pay attention to gas barrier properties. That is, if the gas barrier property of the substrate is too low, the electroluminescent element may be deteriorated by the outside air passing through the substrate, which is not desirable. For this reason, when a resin base material is used, it is desirable to ensure gas barrier properties by a method such as providing a dense silicon oxide film on at least one plate surface.

  Examples of the glass include soda glass, blue plate glass, and non-alkali glass. Among these, alkali-free glass is preferable in that there are few eluted ions from the glass.

  There is no restriction | limiting in the shape of the base material 31, For example, things, such as plate shape, a film form, or a sheet form, can be used.

  Moreover, although there is no restriction | limiting in the film thickness of the base material 31, Usually, it is 5 micrometers or more, Preferably it is 20 micrometers or more, On the other hand, it is 20 mm or less normally, Preferably it is 10 mm or less. It is preferable that the thickness of the substrate is 5 μm or more because the possibility that the strength of the electroluminescent element is insufficient is reduced. It is preferable that the thickness of the substrate is 20 mm or less because the cost is suppressed and the mass does not become heavy.

  When the material of the base material 31 is glass, the film thickness is usually 0.01 mm or more, preferably 0.1 mm or more, and is usually 1 cm or less, preferably 0.5 cm or less. It is preferable that the film thickness of the glass substrate 31 is 0.01 mm or more because the mechanical strength increases and it is difficult to break. Moreover, it is preferable that the film thickness of the glass base material 31 is 0.5 cm or less because the mass does not increase.

<6.2. Anode (32)>
The anode 32 plays a role of hole injection into the hole injection layer 33. The material of the anode 32 is not particularly limited as long as the effects of the present invention are not significantly impaired. Suitable examples of the material of the anode 32 include metals such as aluminum, gold, silver, nickel, palladium, and platinum; metal oxides such as indium oxide and tin oxide; metal halides such as copper iodide; carbon black; Examples thereof include conductive polymers such as (3-methylthiophene), polypyrrole, and polyaniline; or the metal oxide-containing layer according to the present invention.

  Although there is no restriction | limiting in the method of forming the anode 32, Usually, it carries out by dry-type film-forming methods, such as sputtering method and a vacuum evaporation method. In addition, metal fine particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, and conductive polymer fine powder are dispersed in an appropriate binder resin solution and applied onto the substrate 31. Thus, the anode 32 can also be formed. Further, when a conductive polymer is used as the anode 32, a thin film is directly formed on the substrate 31 by electrolytic polymerization, or the anode 32 is formed by applying a conductive polymer on the substrate 31. You can also The anode 32 may have a laminated structure of different materials. Moreover, when using a metal oxide content layer, it can form according to the formation method of the metal oxide content layer which concerns on the above-mentioned this invention.

  The film thickness of the anode 32 varies depending on the required transparency. When transparency is required for the anode 32, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the film thickness of the anode 2 is usually 5 to 1000 nm, preferably 10%. About 500 nm. If it may be opaque, the anode 32 may be the same as the substrate 31. It is also possible to laminate different conductive materials on the anode 32 described above. The visible light transmittance can be measured with a spectrophotometer (for example, U-4100 manufactured by Hitachi High-Tech).

<6.3. Hole Injection Layer (33)>
A hole injection layer 33 is provided on the anode 32. The conditions required for the material of the hole injection layer 33 include a high hole injection efficiency from the anode, an efficient transport of the injected holes, and a hole injection barrier with the hole transport layer. Is a small material. For this purpose, a small difference between the ionization potential of the hole injection material and the work function of the anode is required. It is also necessary that the film is highly transparent to visible light. Furthermore, the material of the hole injection layer 33 has good contact with the anode 32 and can form a uniform thin film, and is thermally stable, that is, the melting point and the glass transition temperature (Tg) are high. The glass transition temperature is required to be 200 ° C. or higher and 75 ° C. or higher.

  Examples of the material for the hole injection layer 33 in consideration of such requirements include porphyrin derivatives, phthalocyanine compounds (Japanese Patent Laid-Open No. 63-295695), starburst aromatic triamines (Japanese Patent Laid-Open No. 4-308688). Organic compounds such as, sputtered carbon films (Japanese Patent Laid-Open No. 8-31573), metal oxides such as vanadium oxide, ruthenium oxide, molybdenum oxide (the 43rd Joint Conference on Applied Physics, 27a-SY-9, 1996), or a metal oxide-containing layer according to the present invention. These compounds may be used alone or in combination as necessary.

  Typical examples of the material of the hole injection layer 33 include a porphyrin compound and a phthalocyanine compound, but these compounds may have a central metal or may be metal-free. Specific examples of the phthalocyanine compound include 29H, 31H-phthalocyanine, copper (II) phthalocyanine, zinc (II) phthalocyanine, titanium phthalocyanine oxide, copper (II) -4,4 ′, 4 ″, 4 ′ ″-tetraaza -29H, 31H-phthalocyanine.

  In addition, a preferable example of the hole injection layer 33 includes a system in which an electron accepting compound is mixed with a hole transporting polymer. Examples of such hole transporting polymers include polythiophene (Japanese Patent Laid-Open No. 10-92584), polyaniline, and aromatic amine-containing polyether (Japanese Patent Laid-Open No. 2000-36390).

  The electron accepting compound is preferably at least one compound selected from the following compound group.

  As a method for forming a thin film of the hole injection layer 33, in the case of a compound having a sublimation property, in the case of a compound soluble in a solvent, a wet process such as a known spin coating method or an ink jet method is used. In the case of a film method or an inorganic material, a sputtering method, an electron beam evaporation method, or a plasma CVD method can be further used. In addition, when the hole injection layer 33 is a metal oxide content layer, it can form according to the formation method of the metal oxide content layer concerning the present invention.

  Although there is no restriction | limiting in the film thickness of the positive hole injection layer 33, Usually, 3 to 300 nm, Preferably, it is 10 to 100 nm. If the film thickness is within the above range, the conditions required for the hole injection layer 33 can be satisfied.

<6.4. Hole Transport Layer (34)>
A hole transport layer 34 is provided on the hole injection layer 33. Conditions required for the material of the hole transport layer 34 include a material that has a high hole injection efficiency from the hole injection layer 33 and can efficiently transport the injected holes to the light emitting layer 35. That is. For this purpose, the difference between the ionization potential of the material used for the hole injection layer 33 and the ionization potential of the material used for the hole transport layer 34 is small, the transparency to visible light is high, and the hole mobility is high. It is required to be large and have excellent stability against oxidation, and it is difficult for impurities to become traps to be generated during manufacture and use. In addition to the above general requirements, when the application for in-vehicle display is considered, the element is further required to have heat resistance. Accordingly, a material having a glass transition temperature (Tg) of 75 ° C. or higher is desirable.

  Examples of the material of the hole transport layer 34 include two or more tertiary amines represented by 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl. A starburst structure such as an aromatic diamine having at least one fused aromatic ring substituted with a nitrogen atom (Japanese Patent Laid-Open No. 5-234681), 4,4 ′, 4 ″ -tris (1-naphthylphenylamino) triphenylamine (J. Lumin. 1997, 72-74, 985.), an aromatic amine compound comprising a tetramer of triphenylamine (Chem. Commun. 1996, 2175.), 2, 2 ′, Spiro compounds such as 7,7′-tetrakis- (diphenylamino) -9,9′-spirobifluorene (Synth. Metals 1997, 91, 209.) or the metal oxide-containing layer according to the present invention It is below. These compounds may be used alone, if necessary, each may be mixed.

  The hole transport layer 34 is formed by laminating the aromatic amine compound or the like on the hole injection layer 33 by a wet film formation method or a vacuum deposition method.

  In the case of a wet film-forming method, one or more of the above-mentioned aromatic amine compounds and, if necessary, additives such as a binder resin and a coating property improving agent that do not trap holes are added and dissolved to dissolve the ink. Is applied onto the hole injection layer 33 by a spin coating method or the like, and dried to form the hole transport layer 34.

  Examples of the binder resin include polycarbonate, polyarylate, and polyester. When the amount of the binder resin added is large, the hole mobility is lowered. Therefore, it is desirable that the amount of the binder resin is small, and the amount is preferably 50% by mass or less based on the total amount of the ink.

  In the case of the vacuum evaporation method, the aromatic amine compound is put in a crucible installed in a vacuum vessel, and the inside of the vacuum vessel is evacuated to about 10 −4 Pa with an appropriate vacuum pump, and then the crucible is heated to evaporate. Then, the hole transport layer 34 is formed on the hole injection layer 33 on the substrate placed facing the crucible.

  In addition, when using a metal oxide content layer as the positive hole transport layer 34, it can form according to the formation method of the metal oxide content layer concerning this invention.

  Although there is no restriction | limiting in the film thickness of the positive hole transport layer 34, Usually, 3 to 300 nm, Preferably it is 10 to 100 nm. If the film thickness is within the above range, the conditions required for the hole transport layer 34 can be satisfied. In order to form such a thin film uniformly, a vacuum deposition method is preferable.

<6.5. Light emitting layer (35)>
A light emitting layer 35 is provided on the hole transport layer 34. The light emitting layer is formed of a compound capable of efficiently transporting electrons from the cathode in the direction of the hole transport layer 34 between electrodes to which an electric field is applied.

  Materials satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 63-295695), bisstyrylarylene derivatives (Japanese Patent Laid-Open No. 4-308688), anthracene derivatives (special And compounds described in Kaihei 8-12600, JP-A-11-31588, and the like.

  The method for forming the light emitting layer 35 is not particularly limited, but can be formed by a known vacuum deposition method.

For the purpose of improving the luminous efficiency of the electroluminescent device and changing the emission color, for example, doping a fluorescent dye for laser such as coumarin with an aluminum complex of 8-hydroxyquinoline as a host material has been performed (J. Appl. Phys. 1989, 65, 3610.). The advantage of this method is
1) Luminous efficiency is improved by highly efficient fluorescent dyes.
2) The emission wavelength is variable by selecting the fluorescent dye.
3) Fluorescent dyes that cause concentration quenching can also be used.
4) Fluorescent dyes with poor film properties can also be used.
Etc.

  In order to improve the driving life of the electroluminescent element, it is effective to dope a fluorescent dye using the light emitting layer material as a host material. For example, when a metal complex such as an aluminum complex of 8-hydroxyquinoline is used as a host material and a naphthacene derivative represented by rubrene is doped in an amount of 0.1 to 10% by mass with respect to the host material, Drive stability can be greatly improved.

  In addition to the fluorescent dye, the luminous efficiency of the device is also greatly improved by doping a phosphorescent metal complex in an amount of 1 to 30% by mass with respect to the light emitting layer host material. In this case, as the phosphorescent metal complex, one having iridium, platinum or the like as a central metal and having phenylpyridine, phenylisoquinoline or the like as a ligand can be used.

  Mixing a hole transport material in the light emitting layer 35 is also effective for the purpose of improving the driving stability of the device. As a mixing ratio, 5-50 mass% is a preferable range.

  Although there is no restriction | limiting in the film thickness of the light emitting layer 35, it is 3-300 nm normally, Preferably it is 10-100 nm. If the film thickness is within the above range, the conditions required for the light emitting layer 35 can be satisfied.

<6.6. Electron Transport Layer (36)>
In order to further improve the light emission efficiency of the electroluminescent element 39, it is effective to stack the electron transport layer 36 on the light emitting layer 35. The material used for the electron transport layer 36 is required to easily inject electrons from the cathode 38 and to have a large electron transport capability.

  The material for such an electron transport layer 36 is not particularly limited, but includes an aluminum complex of 8-hydroxyquinoline, an oxadiazole derivative (Appl. Phys. Lett. 1989, 55, 1489.), No. 5-331459), starburst type benzimidazole compound (Japanese Patent Laid-Open No. 10-106749), silole compound (Appl. Phys. Lett. 2002, 80, 189.), or metal oxide-containing layer according to the present invention Is mentioned. These compounds may be used alone or in combination as necessary.

  Furthermore, it is possible to greatly improve the conductivity by mixing an alkali metal with the electron transport layer 36, which means that the electron transport material is reduced by the reaction with the alkali metal and an anion radical that becomes a charge carrier is reduced. This is because it can be generated efficiently (Japanese Patent Laid-Open No. 10-270171). As the alkali metal, lithium, sodium, potassium, cesium or the like is used, and the content of the alkali metal in the electron transport layer is preferably in the range of 1 to 50% by mass. As a method of mixing the alkali metal, co-evaporation of an electron transport material and an alkali metal is usually used.

  Although there is no restriction | limiting in the film thickness of the electron carrying layer 36, Usually, 3 to 300 nm, Preferably it is 10 to 100 nm. If the film thickness is within the above range, the conditions required for the electron transport layer 36 can be satisfied.

  Examples of the method for forming the electron transport layer 36 include a wet film formation method such as a coating method, or a dry film formation method such as a vacuum evaporation method. In addition, when using a metal oxide content layer for the electron carrying layer 36, it can form according to the formation method of the metal oxide content layer concerning this invention.

<6.7. Electron Injection Layer (37)>
It is also effective to provide an electron injection layer 37 on the electron transport layer 36 in order to facilitate electron injection from the cathode 38.

  As the material used for the electron injection layer 37, a compound having a high electron affinity is preferable. For example, an aluminum complex of 8-hydroxyquinoline, a fullerene derivative, or a metal oxide-containing layer according to the present invention can be used. These compounds may be used alone or in combination as necessary.

  Although there is no restriction | limiting in the film thickness of the electron injection layer 37, Usually, 3 to 300 nm, Preferably it is 10 to 100 nm. If the film thickness is within the above range, the conditions required for the electron injection layer 37 can be satisfied.

  Examples of the method for forming the electron injection layer 37 include a wet film formation method such as a coating method, or a dry film formation method such as a vacuum evaporation method. In addition, when using a metal oxide content layer as the electron injection layer 37, it can form according to the formation method of the metal oxide content layer concerning this invention.

<6.8. Cathode (38)>
The cathode 38 serves to inject electrons into the light emitting layer 35. The material of the cathode 38 is not particularly limited, and the material used for the anode 32 can be used. However, for efficient electron injection, it is preferable to use a metal having a low work function. For example, a suitable metal such as tin, magnesium, indium, calcium, aluminum, silver, or an alloy thereof is used. Examples of the alloy include low work function alloy electrodes such as a magnesium-silver alloy, a magnesium-indium alloy, and an aluminum-lithium alloy.

Furthermore, lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), lithium oxide (Li ₂ O), cesium carbonate (Cs ₂ CO ₃ ) are provided at the interface between the cathode 38 and the electron transport layer 36 or the electron injection layer 37. ), Inserting an ultrathin insulating film (film thickness of 0.1 to 5 nm) such as a lithium complex of 8-hydroxyquinoline is also an effective method for improving the efficiency of the device (Appl. Phys. Lett. 1997, 70, 152., IEEE Trans. Electron. Devices, 1997, 44, 1245., SID 04 Digest, 2004, 154., JP 11-233262 A).

  The film thickness of the cathode 38 is usually the same as that of the anode 32. For the purpose of protecting the cathode 38 made of a low work function metal, further laminating a metal layer having a high work function and stable to the atmosphere on the cathode increases the stability of the device. For this purpose, metals such as aluminum, silver, copper, nickel, chromium, gold and platinum are used.

  FIG. 2 shows an embodiment of the electroluminescent element of the present invention, and the present invention is not limited to the illustrated configuration. For example, a stacked structure opposite to that shown in FIG. 2 is adopted, that is, a cathode 38, an electron injection layer 37, an electron transport layer 36, a light emitting layer 35, a hole transport layer 34, a hole injection layer 33, an anode on the substrate 31. It is also possible to stack 32 in this order.

  The electroluminescent element of the present invention can be applied to any of a single element, an element having a structure arranged in an array, and an element having a structure in which an anode and a cathode are arranged in an XY matrix.

<7. Photoelectric conversion element>
The photoelectric conversion element according to the present invention includes, on a base material, at least a pair of electrodes, an active layer existing between the pair of electrodes, and a buffer layer between the active layer and one electrode of the pair of electrodes. And have. The photoelectric conversion element according to the present invention is characterized by having the metal oxide-containing layer according to the present invention.

  As shown in FIG. 3, an embodiment of the photoelectric conversion element according to the present invention includes a lower electrode 101, a lower buffer layer 102, an active layer 103, an upper buffer layer 104, and an upper electrode on a substrate 106. 105 has a layered structure formed sequentially. In the present invention, the lower electrode means an electrode laminated on the substrate 106 side, and the upper electrode means an electrode laminated above the lower electrode when the substrate 106 is used as the bottom. . In the present invention, the lower electrode 101 and the upper electrode 105 may be collectively referred to as a pair of electrodes. In addition, the lower buffer layer 102 and the upper buffer layer 104 are not essential components, and may be provided arbitrarily, and may include only one of the lower buffer layer 102 and the upper buffer layer 104. In addition, the photoelectric conversion element 107 may optionally have another layer other than the above. Hereinafter, each component of the photoelectric conversion element 107 will be described.

<7.1. Substrate (106)>
The photoelectric conversion element 107 has a base material 106 that usually serves as a support. But the photoelectric conversion element which concerns on this invention does not need to have the base material 106. FIG.

  The material of the substrate 106 is not particularly limited as long as the effects of the present invention are not significantly impaired. Preferable examples of the material of the substrate 106 include inorganic materials such as quartz, glass, sapphire, and titania, and flexible substrates. Specific examples of the flexible substrate include, but are not limited to, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluororesin film, vinyl chloride. Or polyolefin such as polyethylene; organic material (resin base material) such as cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene or epoxy resin; paper material such as paper or synthetic paper; silver, Examples of the composite material include a metal foil such as copper, stainless steel, titanium, or aluminum whose surface is coated or laminated in order to provide insulation.

  Among these, the method for forming a metal oxide-containing layer according to the present invention is particularly effective when used for a flexible substrate. For example, when a metal oxide-containing layer is formed by a conventional method, it is extremely difficult to use a resin base material having a low glass transition temperature because a high-temperature process is required. On the other hand, the present invention can be applied to a resin substrate having a low glass transition temperature because the metal oxide-containing layer can be produced by a low-temperature process. In addition, even when a composite material in which the above-described metal foil is provided with an insulating property is used as a base material, since the film thickness is very small, when a metal oxide-containing layer is manufactured by a high-temperature process as in the past, The material will be distorted. Therefore, the present invention is extremely effective even when a composite material in which an insulating property is imparted to a metal foil is used as a base material. Furthermore, since a flexible base material can be used for the present invention as described above, an electronic device can be manufactured by a roll-to-roll system, and productivity is improved.

  Examples of the glass include soda glass, blue plate glass, and non-alkali glass. Among these, alkali-free glass is preferable in that there are few eluted ions from the glass.

  There is no restriction | limiting in the shape of the base material 106, For example, things, such as plate shape, a film form, or a sheet form, can be used.

  Moreover, although there is no restriction | limiting in the film thickness of the base material 106, it is 5 micrometers or more normally, Preferably it is 20 micrometers or more, on the other hand, 20 mm or less normally, Preferably it is 10 mm or less. It is preferable that the thickness of the substrate is 5 μm or more because the possibility that the strength of the photoelectric conversion element is insufficient is reduced. It is preferable that the thickness of the substrate is 20 mm or less because the cost is suppressed and the mass does not become heavy. When the material of the substrate 108 is glass, the film thickness is usually 0.01 mm or more, preferably 0.1 mm or more, and is usually 1 cm or less, preferably 0.5 cm or less. It is preferable that the film thickness of the glass substrate 108 is 0.01 mm or more because the mechanical strength increases and it is difficult to break. Moreover, it is preferable that the film thickness of the glass substrate 106 is 0.5 cm or less because the mass does not increase.

<7.2. Pair of electrodes (lower electrode 101 and upper electrode 105)>
The pair of electrodes (101, 106) has a function of collecting holes and electrons generated by light absorption. Accordingly, the pair of electrodes includes an electrode suitable for collecting holes (hereinafter sometimes referred to as an anode) and an electrode suitable for collecting electrons (hereinafter sometimes referred to as a cathode). It is preferable to use it. Any one of the pair of electrodes may be translucent, and both may be translucent. Translucency means that sunlight passes through 40% or more. Further, the solar light transmittance of the transparent electrode is preferably 70% or more in order to allow light to reach the active layer through the transparent electrode. The light transmittance can be measured with a normal spectrophotometer.

  The anode is an electrode generally made of a conductive material having a work function higher than that of the cathode and having a function of smoothly extracting holes generated in the active layer.

  Examples of materials for the anode include conductive metal oxides such as nickel oxide, tin oxide, indium oxide, indium tin oxide (ITO), indium-zinc oxide (IZO), titanium oxide, indium oxide, and zinc oxide; Examples thereof include metals such as gold, platinum, silver, chromium and cobalt, or alloys thereof. These substances are preferable because they have a high work function, and further, a conductive polymer material represented by PEDOT: PSS in which a polythiophene derivative is doped with polystyrene sulfonic acid can be stacked. When laminating such a conductive polymer, the work function of this conductive polymer material is high, so even if it is not a material with a high work function as described above, it is suitable for cathodes such as Al and Mg. Metals can also be widely used. PEDOT: PSS in which a polythiophene derivative is doped with polystyrene sulfonic acid, or a conductive polymer material in which polypyrrole, polyaniline, or the like is doped with iodine or the like can also be used as an anode material.

  When the anode is a transparent electrode, it is preferable to use a light-transmitting conductive metal oxide such as ITO, zinc oxide or tin oxide, and ITO is particularly preferable.

  The film thickness of the anode is not particularly limited, but is usually 10 nm or more, preferably 20 nm or more, and more preferably 50 nm or more. On the other hand, it is usually 10 μm or less, preferably 1 μm or less, more preferably 500 nm or less. When the thickness of the anode is 10 nm or more, the sheet resistance is suppressed, and when the thickness of the anode is 10 μm or less, light can be efficiently converted into electricity without decreasing the light transmittance. When the anode is a transparent electrode, it is necessary to select a film thickness that can achieve both light transmittance and sheet resistance.

  The sheet resistance of the anode is not particularly limited, but is usually 1Ω / □ or more, on the other hand, 1000Ω / □ or less, preferably 500Ω / □ or less, more preferably 100Ω / □ or less.

  Examples of the anode forming method include a vacuum film forming method such as a vapor deposition method or a sputtering method, or a wet coating method in which an ink containing nanoparticles or a precursor is applied to form a film.

  The cathode is generally an electrode made of a conductive material having a low work function, and having a function of smoothly extracting electrons generated in the active layer 103. The cathode is adjacent to the electron extraction layer.

  Examples of cathode materials include platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, cesium, calcium, and magnesium, and alloys thereof; lithium fluoride And inorganic salts such as cesium fluoride and metal oxides such as nickel oxide, aluminum oxide, lithium oxide, and cesium oxide. These materials are preferable because they are materials having a low work function. Similarly to the anode, a material having a high work function can be used for the cathode by using an n-type semiconductor such as titania having conductivity as the electron extraction layer. From the viewpoint of electrode protection, the cathode material is preferably a metal such as platinum, gold, silver, copper, iron, tin, aluminum, calcium or indium, or an alloy using these metals such as indium tin oxide.

  The film thickness of the cathode is not particularly limited, but is usually 10 nm or more, preferably 20 nm or more, more preferably 50 nm or more. On the other hand, it is usually 10 μm or less, preferably 1 μm or less, more preferably 500 nm or less. When the film thickness of the cathode is 10 nm or more, the sheet resistance is suppressed, and when the film thickness of the cathode is 10 μm or less, light can be efficiently converted into electricity without decreasing the light transmittance. When the cathode is a transparent electrode, it is necessary to select a film thickness that achieves both light transmittance and sheet resistance.

  The sheet resistance of the cathode is not particularly limited, but is usually 1000Ω / □ or less, preferably 500Ω / □ or less, and more preferably 100Ω / □ or less. Although there is no restriction on the lower limit, it is usually 1Ω / □ or more.

  As a method for forming the cathode, there are a vacuum film formation method such as a vapor deposition method or a sputtering method, or a wet coating method in which an ink containing nanoparticles or a precursor is applied to form a film.

  Furthermore, the anode and the cathode may have a laminated structure of two or more layers. In addition, characteristics (electrical characteristics, wettability, etc.) may be improved by performing a surface treatment on the anode and the cathode.

  After laminating the anode and cathode, the photoelectric conversion element is usually heated in a temperature range of 50 ° C. or higher, preferably 80 ° C. or higher, and usually 300 ° C. or lower, preferably 280 ° C. or lower, more preferably 250 ° C. or lower. Is preferable (this step may be referred to as an annealing treatment step). By performing the annealing treatment step at a temperature of 50 ° C. or more, an effect of improving the adhesion between the layers of the photoelectric conversion element, for example, the adhesion between the electron extraction layer and the cathode and / or the electron extraction layer and the active layer described later is obtained. Therefore, it is preferable. By improving the adhesion between the layers, the thermal stability and durability of the thin-film solar cell element can be improved. It is preferable to set the temperature of the annealing treatment step to 300 ° C. or lower because the possibility that the organic compound in the active layer is thermally decomposed is reduced. In the annealing treatment step, stepwise heating may be performed within the above temperature range.

  The heating time is usually 1 minute or longer, preferably 3 minutes or longer, and usually 3 hours or shorter, preferably 1 hour or shorter. The annealing treatment step is preferably terminated when the open-circuit voltage, the short-circuit current, and the fill factor, which are parameters of the solar cell performance, reach a constant value. Further, the annealing treatment step is preferably performed under normal pressure and in an inert gas atmosphere.

  As a heating method, the organic thin film solar cell element may be placed on a heat source such as a hot plate, or the organic thin film solar cell element may be placed in a heating atmosphere such as an oven. The heating may be performed batchwise or continuously.

<7.3. Lower buffer layer 102, upper buffer layer 104>
As described above, the photoelectric conversion element according to this embodiment includes the lower buffer layer 102 between the lower electrode 101 and the active layer 103, and the upper buffer layer 104 between the upper electrode 105 and the active layer 103. . The lower buffer layer 102 and the upper buffer layer 104 each have a function of improving the electron extraction efficiency from the active layer 103 to the cathode or the hole extraction efficiency from the active layer 103 to the anode. Note that a buffer layer having a function of improving the electron extraction efficiency from the active layer 103 to the cathode is referred to as an electron extraction layer, and a buffer layer having a function of improving the electron extraction efficiency from the active layer 103 to the cathode is referred to as a hole extraction layer. As described above, the lower buffer layer 102 and the upper buffer layer 104 are not essential components, and the organic thin film solar cell element 4 may not include the lower buffer layer 102 and the upper buffer layer 104. Moreover, you may have only any one layer.

  Either the lower buffer layer 102 or the upper buffer layer 104 may be an electron extraction layer or a hole extraction layer, but when the lower electrode 101 is a cathode and the upper electrode 105 is an anode, the lower buffer layer 102 is an electron extraction layer. The upper buffer layer 104 is a hole extraction layer. On the other hand, when the lower electrode 101 is an anode and the upper electrode 105 is a cathode, the lower buffer layer 102 is a hole extraction layer and the upper buffer layer 104 is an electron extraction layer.

<7.3.1. Electron extraction layer>
The electron extraction layer is not particularly limited and is not particularly limited as long as it is a material capable of improving the efficiency of extracting electrons from the active layer to the cathode. Specifically, an inorganic compound or an organic compound is mentioned. Examples of the inorganic compound material include alkali metal salts such as lithium, sodium, potassium, and cesium; and n-type semiconductor characteristic metal oxides such as zinc oxide, titanium oxide, aluminum oxide, and indium oxide. As the n-type semiconductor characteristic metal oxide, zinc oxide, titanium oxide or indium oxide is preferable, and zinc oxide or titanium oxide is particularly preferable. Specific examples of the organic compound material include bathocuproin (BCP), bathophenanthrene (Bphen), (8-hydroxyquinolinato) aluminum (Alq3), boron compound, oxadiazole compound, benzimidazole compound, and naphthalenetetracarboxylic acid. Examples include acid anhydrides (NTCDA), perylene tetracarboxylic acid anhydrides (PTCDA), and phosphine compounds having a double bond with a Group 16 element of the periodic table such as phosphine oxide compounds or phosphine sulfide compounds.

  In addition, when using a metal oxide as an electron extraction layer, the metal oxide content layer based on this invention can be used as an electron extraction layer. When the electron extraction layer is composed of a plurality of layers, at least one layer may be a metal oxide-containing layer according to the present invention.

  The metal oxide-containing layer according to the present invention is preferably used as an electron extraction layer in that it is reasonably hard and excellent in film uniformity and can improve the photoelectric conversion efficiency of the photoelectric conversion element according to the present invention. . The coating method using an ink containing an unsaturated carboxylic acid metal salt enables uniform film formation, and the resulting film is made of a metal oxide having high hardness and high characteristics as a main component, resulting in good charge. It is thought that (especially electron) transport function can be exhibited.

  There is no restriction | limiting in the formation method as a formation method of an electron taking-out layer. For example, when a material having sublimation property is used, it can be formed by a dry film forming method such as a vacuum evaporation method. For example, when a material soluble in a solvent is used, the film can be formed by a wet film formation method such as a spin coating method or an ink jet method. Especially, when forming the metal oxide content layer concerning the present invention as an electron taking-out layer, the wet film-forming method using the above-mentioned composition is used. An electron extraction layer can be formed by coating an ink containing an unsaturated carboxylic acid metal salt according to the present invention on a substrate, followed by heat treatment.

  As an ink application method, any method can be used. Examples thereof include spin coating, gravure coating, kiss coating, roll brushing, spray coating, air knife coating, wire barber coating, pipe doctor method, impregnation / coating method, and curtain coating method. Moreover, only 1 type of method may be used as a coating method, and it can also be used in combination of 2 or more types.

  The total film thickness of the electron extraction layer is not particularly limited, but is usually 0.5 nm or more, preferably 1 nm or more, more preferably 5 nm or more, and particularly preferably 10 nm or more. On the other hand, it is usually 1 μm or less, preferably 700 nm or less, more preferably 400 nm or less, and particularly preferably 200 nm or less. When the film thickness of the electron extraction layer is within the above range, uniform application is facilitated and the electron extraction function can be exhibited well.

<7.3.2. Hole extraction layer>
There is no particular limitation on the material of the hole extraction layer, and any material can be used as long as it can improve the efficiency of extracting holes from the active layer to the anode. Specifically, polythiophene, polypyrrole, polyacetylene, triphenylenediamine, polyaniline or the like is doped with at least one of sulfonic acid and iodine, polythiophene derivatives having a sulfonyl group as a substituent, and conductive properties such as arylamine. And organic oxides, Nafion, p-type semiconductor compounds described later, copper oxide, nickel oxide, manganese oxide, molybdenum oxide, or metal oxide such as vanadium oxide or tungsten oxide. The hole extraction layer may be a metal oxide-containing layer according to the present invention.

  Among them, a conductive polymer doped with sulfonic acid is preferable, and (3,4-ethylenedioxythiophene) poly (styrenesulfonic acid) (PEDOT: PSS) in which a polythiophene derivative is doped with polystyrene sulfonic acid is more preferable. It is. A thin film of metal such as gold, indium, silver or palladium can also be used. A thin film of metal or the like may be formed alone or in combination with the above organic material.

  The total film thickness of the hole extraction layer is not particularly limited, but is usually 0.5 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the film thickness of the hole extraction layer is 0.5 nm or more, it functions as a buffer material. When the film thickness of the hole extraction layer is 400 nm or less, holes are easily extracted, Conversion efficiency can be improved.

  There is no restriction | limiting in the formation method of a positive hole taking-out layer. For example, when a material having sublimation property is used, it can be formed by a dry film forming method such as a vacuum evaporation method. For example, when a material soluble in a solvent is used, the film can be formed by a wet film formation method such as a spin coating method or an ink jet method. When a semiconductor material is used for the hole extraction layer, the precursor may be converted into a semiconductor compound after forming the layer using the precursor, similarly to the low-molecular organic semiconductor compound of the organic active layer described later.

  Especially, when using PEDOT: PSS as a material of a hole taking-out layer, it is preferable to form a hole taking-out layer by the method of apply | coating a dispersion liquid. Examples of the dispersion of PEDOT: PSS include CLEVIOS (registered trademark) series manufactured by Heraeus and ORGACON (registered trademark) series manufactured by Agfa.

  When the hole extraction layer is formed by a coating method, a surfactant may be further contained in the coating solution. By using the surfactant, generation of at least one of dents due to adhesion of minute bubbles or foreign matters and uneven coating in the drying process is suppressed. Known surfactants (cationic surfactants, anionic surfactants, nonionic surfactants) can be used as the surfactant. Of these, silicon-based surfactants, acetylenic diol-based surfactants, and fluorine-based surfactants are preferable. In addition, as surfactant, only 1 type may be used and 2 or more types may be used together by arbitrary combinations and a ratio.

<7.4. Active layer (103)>
The active layer 103 refers to a layer in which photoelectric conversion is performed, and usually includes a p-type semiconductor compound and an n-type semiconductor compound. The p-type semiconductor compound is a compound that works as a p-type semiconductor material, and the n-type semiconductor compound is a compound that works as an n-type semiconductor material. When the photoelectric conversion element 107 receives light, the light is absorbed by the active layer 103, electricity is generated at the interface between the p-type semiconductor compound and the n-type semiconductor compound, and the generated electricity is extracted from the electrodes 101 and 105.

  As the material of the active layer 103, either an inorganic compound or an organic compound may be used, but a layer that can be formed by a simple coating process is preferable, and the metal oxide-containing layer according to the present invention may be used. Good.

  As the layer structure of the active layer 103, a thin film stack type in which a p-type semiconductor compound layer and an n-type semiconductor compound layer are stacked, a bulk heterojunction type having a layer in which a p-type semiconductor compound and an n-type semiconductor compound are mixed, p For example, a layer in which a p-type semiconductor compound layer, a layer (i layer) in which a p-type semiconductor compound and an n-type semiconductor compound are mixed, and an n-type semiconductor compound layer are stacked. Among these, a bulk heterojunction type having a layer in which a p-type semiconductor compound and an n-type semiconductor compound are mixed is preferable.

  The thickness of the active layer 103 is not particularly limited, but is usually 10 nm or more, preferably 50 nm or more, and is usually 1 μm or less, preferably 500 nm or less, more preferably 200 nm or less. It is preferable that the thickness of the active layer 103 is 10 nm or more because the uniformity of the film is maintained and a short circuit is less likely to occur. In addition, it is preferable that the thickness of the active layer 103 is 1 μm or less from the viewpoint that the internal resistance is small and that the diffusion of charges is good without the electrodes (cathode-anode) being separated too much.

  A method for forming the active layer 103 is not particularly limited, but a coating method is preferable. As the coating method, any method can be used, for example, spin coating method, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire barber coating method, Examples include the pipe doctor method, the impregnation / coating method, and the curtain coating method.

  For example, the p-type semiconductor compound layer and the n-type semiconductor compound layer can be produced by applying a coating liquid containing a p-type semiconductor compound or an n-type semiconductor compound. Moreover, the layer in which the p-type semiconductor compound and the n-type semiconductor compound are mixed can be prepared by applying a coating solution containing the p-type semiconductor compound and the n-type semiconductor compound. As will be described later, the semiconductor compound precursor may be converted into a semiconductor compound after the coating liquid containing the semiconductor compound precursor is applied.

In this specification, “semiconductor” is defined by the magnitude of carrier mobility in a solid state. As is well known, the carrier mobility is an index indicating how fast (or many) charges (electrons or holes) can be transferred. Specifically, the “semiconductor” in this specification has a carrier mobility at room temperature of usually 1.0 × 10 ⁻⁶ cm ² / V · s or more, preferably 1.0 × 10 ⁻⁵ cm ² / V · s or more. Preferably it is 5.0 × 10 ⁻⁵ cm ² / V · s or more, more preferably 1.0 × 10 ⁻⁴ cm ² / V · s or more. The carrier mobility can be measured, for example, by measuring the IV characteristics of the field effect transistor or the time-of-flight method. In addition, as a characteristic of the semiconductor layer according to the present invention, carrier mobility at room temperature is 1.0 × 10 ⁻⁶ cm ² / V · s or more, preferably 1.0 × 10 ⁻⁵ cm ² / V · s or more, more preferably It is desirable to be 5.0 × 10 ⁻⁵ cm ² / V · s or more, more preferably 1.0 × 10 ⁻⁴ cm ² / V · s or more.

<7.4.1. p-type semiconductor compound>
The p-type semiconductor compound included in the active layer 103 is not particularly limited, and examples thereof include a low-molecular organic semiconductor compound, a high-molecular organic semiconductor compound, an inorganic semiconductor compound, and an organic-inorganic composite semiconductor compound.

<7.4.1.1. Low molecular organic semiconductor compound>
The molecular weight of the low-molecular organic semiconductor compound is not particularly limited both at the upper limit and the lower limit, but is usually 5000 or less, preferably 2000 or less, and is usually 100 or more, preferably 200 or more.

Further, the low molecular organic semiconductor compound preferably has crystallinity. A p-type semiconductor compound having crystallinity has a strong intermolecular interaction, and holes generated at the interface between the p-type semiconductor compound and the n-type semiconductor compound in the active layer can be efficiently transported to the anode. In the present specification, crystallinity is a property of a compound that takes a three-dimensional periodic arrangement with uniform orientation due to intermolecular interaction or the like. Examples of the crystallinity measurement method include an X-ray diffraction method (XRD) or a mobility measurement method using a field effect transistor (FET). In particular, in the mobility measurement using a field effect transistor, the hole mobility is usually 1.0 × 10 ⁻⁶ cm ² / Vs or more, preferably 1.0 × 10 ⁻⁵ cm ² / Vs or more, 5.0 More preferably × 10 ⁻⁵ cm ² / Vs or more, and even more preferably 1.0 × 10 ⁻⁴ cm ² / Vs or more. On the other hand, it is usually 1.0 × 10 ⁴ cm ² / Vs or less, preferably 1.0 × 10 ³ cm ² / Vs or less, and more preferably 5.0 × 10 ² cm ² / Vs or less. It is preferable that the hole mobility is 1.0 × 10 ⁻⁶ cm ² / Vs or more from the viewpoint that effects such as improvement of the hole diffusion rate, improvement of short circuit current, and improvement of conversion efficiency of the photoelectric conversion element can be obtained. A mobility measuring method using a field effect transistor can be performed by a method described in a publicly known document (Japanese Patent Laid-Open No. 2011-61095).

  The low-molecular organic semiconductor compound is not particularly limited as long as it can function as a p-type semiconductor material. Specifically, condensed aromatic hydrocarbons such as naphthacene, pentacene, or pyrene; α-sexithiophene, etc. Oligothiophenes containing 4 or more thiophene rings; including at least one of thiophene ring, benzene ring, fluorene ring, naphthalene ring, anthracene ring, thiazole ring, thiadiazole ring and benzothiazole ring, and a total of 4 or more linked And a macrocyclic compound such as a phthalocyanine compound and a metal complex thereof, or a porphyrin compound such as tetrabenzoporphyrin and a metal complex thereof. Preferably, they are a phthalocyanine compound and its metal complex, or a porphyrin compound and its metal complex.

Examples of the porphyrin compound and its metal complex (Z ¹ in the following formula is CH), and the phthalocyanine compound and its metal complex (Z ¹ in the following formula is N) include compounds having the following structures.

Here, Met represents a metal or two hydrogen atoms. The metal includes a divalent metal such as Cu, Zn, Pb, Mg, Pd, Ag, Co, or Ni, and an axial ligand 3 valence or more metals, for _{example, TiO, VO, SnCl 2,} AlCl, InCl , or Si (OH) ₂ may also be mentioned.

Z ¹ in the above formula is CH or N.

R ^{11 to} R ¹⁴ in the above formula are each independently a hydrogen atom or an alkyl group having 1 to 24 carbon atoms. The alkyl group having 1 to 24 carbon atoms is a saturated or unsaturated chain hydrocarbon group having 1 to 24 carbon atoms or a saturated or unsaturated cyclic hydrocarbon group having 3 to 24 carbon atoms. Among these, a saturated or unsaturated chain hydrocarbon group having 1 to 12 carbon atoms or a saturated or unsaturated cyclic hydrocarbon group having 3 to 12 carbon atoms is preferable.

  Among the phthalocyanine compounds and metal complexes thereof, 29H, 31H-phthalocyanine, copper phthalocyanine complex, zinc phthalocyanine complex, titanium phthalocyanine oxide complex, magnesium phthalocyanine complex, lead phthalocyanine complex or copper 4,4 ′, 4 ″, 4 '' '-Tetraaza-29H, 31H-phthalocyanine complex, more preferably 29H, 31H-phthalocyanine or copper phthalocyanine complex. One of the above compounds may be used, or a mixture of a plurality of compounds may be used.

  Among the porphyrin compounds and metal complexes thereof, 5,10,15,20-tetraphenyl-21H, 23H-porphine, 5,10,15,20-tetraphenyl-21H, 23H-porphine cobalt (II), 5,10,15,20-tetraphenyl-21H, 23H-porphine copper (II), 5,10,15,20-tetraphenyl-21H, 23H-porphine zinc (II), 5,10,15,20- Tetraphenyl-21H, 23H-porphine nickel (II), 5,10,15,20-tetraphenyl-21H, 23H-porphine vanadium (IV) oxide, 5,10,15,20-tetra (4-pyridyl)- 21H, 23H-porphine, 29H, 31H-tetrabenzo [b, g, l, q] porphine, 2 H, 31H-tetrabenzo [b, g, l, q] porphine cobalt (II), 29H, 31H-tetrabenzo [b, g, l, q] porphine copper (II), 29H, 31H-tetrabenzo [b, g, l, q] porphine zinc (II), 29H, 31H-tetrabenzo [b, g, l, q] porphine nickel (II) or 29H, 31H-tetrabenzo [b, g, l, q] porphine vanadium (IV) oxide And preferably 5,10,15,20-tetraphenyl-21H, 23H-porphine or 29H, 31H-tetrabenzo [b, g, l, q] porphine. Among the above, one kind of compound may be used, or a mixture of plural kinds of compounds may be used.

  Examples of the method for forming a low molecular organic semiconductor compound include a vacuum deposition method and a coating method. The latter is preferred because of the process advantage that coating can be formed. When the coating method is used, there is a method of converting a low molecular organic semiconductor compound precursor into a low molecular organic semiconductor compound after coating. A method using a semiconductor compound precursor is more preferable in that coating film formation is easier.

(Low molecular organic semiconductor compound precursor)
A low molecular organic semiconductor compound precursor is a compound that changes its chemical structure and is converted into a low molecular organic semiconductor compound by applying an external stimulus such as heating or light irradiation. The low molecular organic semiconductor compound precursor is preferably excellent in film formability. In particular, in order to be able to apply the coating method, it is preferable that the precursor itself can be applied in a liquid state, or the precursor is highly soluble in some solvent and can be applied as a solution. For this reason, the solubility with respect to the solvent of a low molecular organic-semiconductor compound precursor is 0.1 mass% or more normally, Preferably it is 0.5 mass% or more, More preferably, it is 1 mass% or more. On the other hand, the upper limit is not particularly limited, but is usually 50% by mass or less, preferably 40% by mass or less.

  The type of the solvent is not particularly limited as long as it can uniformly dissolve or disperse the semiconductor precursor compound. For example, aliphatic hydrocarbons such as hexane, heptane, octane, isooctane, nonane or decane; toluene, xylene , Aromatic hydrocarbons such as cyclohexylbenzene, chlorobenzene or orthodichlorobenzene; lower alcohols such as methanol, ethanol or propanol; ketones such as acetone, methyl ethyl ketone, cyclopentanone or cyclohexanone; ethyl acetate, butyl acetate or methyl lactate Esters such as: Chloroform, methylene chloride, dichloroethane, trichloroethane, trichloroethylene, and other halogen hydrocarbons; Ethyl ether, tetrahydrofuran, dioxane, and other ethers; Dimethyl Formamide or amides such as dimethylacetamide and the like. Of these, aromatic hydrocarbons such as toluene, xylene, cyclohexylbenzene, chlorobenzene, or orthodichlorobenzene; ketones such as acetone, methyl ethyl ketone, cyclopentanone, or cyclohexanone; chloroform, methylene chloride, dichloroethane, trichloroethane, or trichloroethylene Halogen hydrocarbons; ethers such as ethyl ether, tetrahydrofuran or dioxane. More preferably, non-halogen aromatic hydrocarbons such as toluene, xylene or cyclohexylbenzene; non-halogen ketones such as cyclopentanone or cyclohexanone; non-halogen aliphatic ethers such as tetrahydrofuran or 1,4-dioxane is there. Particularly preferred are non-halogen aromatic hydrocarbons such as toluene, xylene or cyclohexylbenzene. In addition, 1 type of solvent may be used independently and 2 or more types of solvents may be used together by arbitrary combinations and a ratio.

  Furthermore, it is preferable that the low molecular organic semiconductor compound precursor can be easily converted into a semiconductor compound. In the step of converting a low molecular organic semiconductor compound precursor to a semiconductor compound, which will be described later, what kind of external stimulus is given to the semiconductor precursor is arbitrary, but usually heat treatment or light treatment is performed. Preferably, it is heat treatment. In this case, the low-molecular organic semiconductor compound precursor preferably has a solvophilic group with respect to a predetermined solvent, which can be eliminated by a reverse Diels-Alder reaction as a part of the skeleton.

  Moreover, it is preferable that a low molecular organic-semiconductor compound precursor is converted into a semiconductor compound with a high yield through a conversion process. At this time, the yield of the semiconductor compound obtained by conversion from the low molecular organic semiconductor compound precursor is arbitrary as long as the characteristics of the photoelectric conversion element are not impaired, but the low molecular organic semiconductor obtained from the low molecular organic semiconductor compound precursor The yield of the compound is usually 90 mol% or more, preferably 95 mol% or more, more preferably 99 mol% or more.

  The low molecular organic semiconductor compound precursor is not particularly limited as long as it has the above characteristics, and specifically, compounds described in JP-A-2007-324587 can be used. Particularly preferred examples include compounds represented by the following formula.

In the above formula, at least one of D ¹ and D ² represents a group that forms a π-conjugated divalent aromatic ring, Z ² -Z ³ is a group that can be removed by heat or light, and Z ² A π-conjugated compound obtained by elimination of —Z ³ represents a low molecular organic semiconductor compound. Further, D ¹ and D ² which are not a group forming a π-conjugated divalent aromatic ring represent a substituted or unsubstituted ethenylene group.

In the compound represented by the above formula, Z ² —Z ³ is eliminated by heat or light as shown in the following chemical reaction formula to form a π-conjugated compound having high planarity. This produced π-conjugated compound is a low-molecular organic semiconductor compound. This low molecular organic semiconductor compound is used as a material having p-type semiconductor characteristics.

  The following are mentioned as an example of a low molecular organic-semiconductor compound precursor. In the following, t-Bu represents a t-butyl group, and Met is the same as described for porphyrin and phthalocyanine.

  Specific examples of the conversion of the low-molecular organic semiconductor compound precursor into the low-molecular organic semiconductor compound include the following.

  The low molecular organic semiconductor compound precursor may have a structure in which positional isomers exist, and in that case, it may be a mixture of a plurality of positional isomers. A mixture of a plurality of positional isomers is preferable because it has a higher solubility in a solvent than a low-molecular organic semiconductor compound precursor composed of a single positional isomer component, and is easy to form a coating film. The reason why the solubility of the mixture of multiple positional isomers is high is that the detailed mechanism is not clear, but the crystallinity of the compound itself is potentially retained, but the mixture of multiple isomers is mixed in the solution. It is assumed that three-dimensional regular intermolecular interaction becomes difficult. The solubility in a non-halogen solvent of a mixture of a plurality of regioisomers is usually 0.1% by mass or more, preferably 1% by mass or more, more preferably 5% by mass or more. Although there is no restriction | limiting in an upper limit, Usually, it is 50 mass% or less, More preferably, it is 40 mass% or less.

<7.4.1.2. Polymer Organic Semiconductor Compound>
The polymer organic semiconductor compound is not particularly limited, and is a conjugated polymer semiconductor such as polythiophene, polyfluorene, polyphenylene vinylene, polythienylene vinylene, polyacetylene or polyaniline; a polymer such as oligothiophene substituted with an alkyl group or other substituents A semiconductor is mentioned. Moreover, the semiconductor polymer which copolymerized 2 or more types of monomer units is also mentioned. Examples of the conjugated polymer include Handbook of Conducting Polymers, 3rd Ed. (2 volumes, 2007), Materials Science and Engineering 2001, 32, 1. , Pure Appl. Chem. 2002, 74, 2031. , Handbook of THIOPHENE-BASED MATERIALS (2 volumes, 2009), polymers described in known literatures and derivatives thereof, and polymers that can be synthesized by combinations of the monomers described can be used. The polymer organic semiconductor compound used as the p-type semiconductor compound may be a single compound or a mixture of a plurality of compounds.

  The monomer skeleton and monomer substituent of the polymer organic semiconductor compound can be selected to control the solubility, crystallinity, film-forming property, HOMO energy level, LUMO energy level, and the like. Moreover, it is preferable that a high molecular organic-semiconductor compound is soluble in the organic solvent at the point which can form an active layer by the apply | coating method when producing a photoelectric conversion element. Specific examples of the polymer organic semiconductor compound include the following, but are not limited thereto.

<7.4.1.3. Inorganic semiconductor compounds>
The inorganic semiconductor compound is not particularly limited, and examples thereof include metal oxides such as copper (I) oxide, nickel oxide, and tin (II) oxide, and p-type doped silicon. These are preferable in terms of high hole mobility. In addition, the metal oxide manufactured with the manufacturing method of the metal oxide content layer concerning this invention can also be used as a p-type semiconductor.

<7.4.1.4. Organic Inorganic Composite Semiconductor Compound>
The organic-inorganic composite semiconductor compound is not particularly limited, and examples thereof include perovskite structure compounds such as lead perovskite structure compounds. For the perovskite structure compound, a constituent material can be selected in order to control solubility, crystallinity, film formability, HOMO energy level, LUMO energy level, and the like. Moreover, it is preferable that the perovskite structure compound is soluble in an organic solvent in that an active layer can be formed by a coating method when a photoelectric conversion element is produced. Specific examples of the perovskite structure compound include CH ₃ NH ₃ PbI ₃ , CH ₃ NH ₃ PbI _x Cl _3−x , CH ₃ NH ₃ PbBr ₃ , CH ₃ NH ₃ SnI ₃ , CH ₃ NH ₃ SnBr ₃ , CH ₃ CH ₂ NH ₃ PbI ₃ and HC (NH ₂ ) ₂ PbI ₃ are exemplified, but not limited thereto.

  As the p-type semiconductor compound, the low molecular organic semiconductor compound is preferably a condensed aromatic hydrocarbon such as naphthacene, pentacene or pyrene, a phthalocyanine compound and a metal complex thereof, or a porphyrin compound such as tetrabenzoporphyrin (BP). The organic complex compound is a conjugated polymer semiconductor such as polythiophene, the inorganic semiconductor compound is p-type doped silicon, and the organic / inorganic composite semiconductor compound is lead perovskite. It is a structural compound. The p-type semiconductor compound used in the active layer may be a single compound or a mixture of multiple compounds.

  The p-type semiconductor compound may have some self-organized structure in the deposited state, or may be in an amorphous state.

  The HOMO (highest occupied molecular orbital) energy level of the p-type semiconductor compound is not particularly limited, and can be selected according to the type of the n-type semiconductor compound described later. In particular, when a fullerene compound is used as an n-type semiconductor compound, the HOMO energy level of the p-type semiconductor compound is usually −5.7 eV or more, more preferably −5.5 eV or more, on the other hand, usually −4.6 eV or less. Preferably it is -4.8 eV or less. When the HOMO energy level of the p-type semiconductor compound is −5.7 eV or more, the characteristics as a p-type semiconductor are improved, and when the HOMO energy level of the p-type semiconductor compound is −4.6 eV or less, Stability is improved and the open circuit voltage (Voc) is also improved.

  The LUMO (lowest unoccupied molecular orbital) energy level of the p-type semiconductor compound is not particularly limited, but can be selected according to the type of the n-type semiconductor compound described later. In particular, when a fullerene compound is used as an n-type semiconductor compound, the LUMO energy level of the p-type semiconductor compound is usually −3.7 eV or more, preferably −3.6 eV or more. On the other hand, it is usually −2.5 eV or less, preferably −2.7 eV or less. When the LUMO energy level of the p-type semiconductor is −2.5 eV or less, the band gap is adjusted, light energy having a long wavelength can be effectively absorbed, and the short-circuit current density is improved. When the LUMO energy level of the p-type semiconductor compound is −3.7 eV or more, electron transfer to the n-type semiconductor compound is likely to occur and the short-circuit current density is improved.

<7.4.2. N-type semiconductor compound>
The n-type semiconductor compound is not particularly limited. Specifically, it is a fullerene compound, a quinolinol derivative metal complex represented by 8-hydroxyquinoline aluminum; a condensed ring such as naphthalenetetracarboxylic acid diimide or perylenetetracarboxylic acid diimide. Tetracarboxylic acid diimides; perylene diimide derivatives, terpyridine metal complexes, tropolone metal complexes, flavonol metal complexes, perinone derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazole derivatives, benzthiazole derivatives, benzothiadiazole derivatives, oxadiazole derivatives, thiadiazoles Derivatives, triazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, benzoquinoline derivatives Bifluoride derivatives, borane derivatives, total fluorides of condensed polycyclic aromatic hydrocarbons such as anthracene, pyrene, naphthacene or pentacene; single-walled carbon nanotubes, n-type polymer semiconductor compounds, metal oxides such as titanium oxide or zinc oxide, An example is n-type doped silicon.

  Among them, fullerene compounds, borane derivatives, thiazole derivatives, benzothiazole derivatives, benzothiadiazole derivatives, N-alkyl-substituted naphthalene tetracarboxylic acid diimides and N-alkyl-substituted perylene diimide derivatives are preferable, fullerene compounds, N-alkyl More preferred are substituted perylene diimide derivatives and N-alkyl substituted naphthalene tetracarboxylic acid diimides, metal oxides such as titanium oxide or zinc oxide, and n-type doped silicon. Among the above, one kind of compound may be used, or a mixture of plural kinds of compounds may be used.

  The LUMO energy level of the n-type semiconductor compound is not particularly limited. For example, the value with respect to the vacuum level calculated by the cyclic voltammogram measurement method is usually −3.85 eV or more, preferably −3.80 eV or more. . In order to efficiently transfer electrons from a p-type semiconductor compound to an n-type semiconductor compound, the relative relationship of LUMO energy levels between the p-type semiconductor compound and the n-type semiconductor compound is important. Specifically, the LUMO energy level of the p-type semiconductor compound is above the LUMO energy level of the n-type semiconductor compound by a predetermined value, in other words, the electron affinity of the n-type semiconductor compound is p-type semiconductor compound. It is preferable that a predetermined energy is larger than the electron affinity. Since the open circuit voltage (Voc) depends on the difference between the HOMO energy level of the p-type semiconductor compound and the LUMO energy level of the n-type semiconductor compound, increasing the LUMO of the n-type semiconductor compound tends to increase the Voc. On the other hand, the LUMO value is usually −1.0 eV or less, preferably −2.0 eV or less, more preferably −3.0 eV or less, and still more preferably −3.3 eV or less. By lowering the LUMO energy level of the n-type semiconductor compound, electrons tend to move and the short circuit current (Jsc) tends to increase.

  As a method for calculating the LUMO energy level of an n-type semiconductor compound, there are a theoretically calculated method and a method of actually measuring. Theoretically calculated methods include semi-empirical molecular orbital methods and non-empirical molecular orbital methods. Examples of the actual measurement method include an ultraviolet-visible absorption spectrum measurement method and a cyclic voltammogram measurement method. Among them, the cyclic voltammogram measurement method is preferable.

  The HOMO energy level of the n-type semiconductor compound is not particularly limited, but is usually −5.0 eV or less, preferably −5.5 eV or less. On the other hand, it is usually −7.0 eV or more, preferably −6.6 eV or more. It is preferable that the HOMO energy level of the n-type semiconductor compound is −7.0 eV or more because light absorption of the n-type semiconductor compound can also be used for power generation. The HOMO energy level of the n-type semiconductor compound is preferably −5.0 eV or less from the viewpoint of preventing reverse movement of holes.

The electron mobility of the n-type semiconductor compound is not particularly limited, but is usually 1.0 × 10 ⁻⁶ cm ² / Vs or more, preferably 1.0 × 10 ⁻⁵ cm ² / Vs or more. 0 × 10 ⁻⁵ cm ² / Vs or more is more preferable, and 1.0 × 10 ⁻⁴ cm ² / Vs or more is more preferable. On the other hand, it is usually 1.0 × 10 ⁴ cm ² / Vs or less, preferably 1.0 × 10 ³ cm ² / Vs or less, and more preferably 5.0 × 10 ² cm ² / Vs or less. The fact that the electron mobility of the n-type semiconductor compound is 1.0 × 10 ⁻⁶ cm ² / Vs or higher can provide effects such as improvement of the electron diffusion rate, improvement of short circuit current, and improvement of conversion efficiency of the photoelectric conversion element. Is preferable. As a method for measuring electron mobility, a field effect transistor (FET) method can be cited, which can be carried out by a method described in a known document (Japanese Patent Laid-Open No. 2007-320957).

  The solubility of the n-type semiconductor compound in toluene at 25 ° C. is usually 0.5% by mass or more, preferably 0.6% by mass or more, and more preferably 0.7% by mass or more. On the other hand, 90 mass% or less is preferable normally, 80 mass% or less is more preferable, and 70 mass% or less is further more preferable. If the solubility of the n-type semiconductor compound in toluene at 25 ° C. is 0.5% by mass or more, the dispersion stability of the n-type semiconductor compound in the solution is improved, and aggregation, sedimentation, separation, and the like are less likely to occur. Therefore, it is preferable.

  Hereinafter, examples of preferable n-type semiconductor compounds will be described.

<7.4.2.1. Fullerene Compound>
As a fullerene compound, what has the partial structure represented by general formula (n1), (n2), (n3), and (n4) is mentioned as a preferable example.

In the above formula, FLN represents fullerene, which is a carbon cluster having a closed shell structure. The carbon number of fullerene is not particularly limited as long as it is an even number of 60 or more and 130 or less. Examples of fullerenes include C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C ₉₄ , C ₉₆ and higher order carbon clusters having more carbons than these. Among these, _C60 or _C70 is preferable. As fullerenes, carbon-carbon bonds on some fullerene rings may be broken. Moreover, some of the carbon atoms constituting the fullerene may be replaced with other atoms. Further, the fullerene may include a metal atom, a non-metal atom, or an atomic group composed of these in a fullerene cage.

a, b, c and d are integers, and the sum of a, b, c and d is usually 1 or more, and usually 5 or less, preferably 3 or less. The partial structures in (n1), (n2), (n3) and (n4) are bonded to the same 5-membered ring or 6-membered ring in the fullerene skeleton. In the general formula (n1), —R ²¹ and — (CH ₂ ) _L are bonded to two adjacent carbon atoms on the same 5-membered ring or 6-membered ring in the fullerene skeleton. . In the general formula (n2), —C (R ²⁵ ) (R ²⁶ ) —N (R ²⁷ ) —C is the same for two adjacent carbon atoms on the same 5-membered ring or 6-membered ring in the fullerene skeleton. (R ²⁸ ) (R ²⁹ ) — are added to form a 5-membered ring. In the general formula (n3), —C (R ³⁰ ) (R ³¹ ) —C—C—C (R) with respect to two adjacent carbon atoms on the same 5-membered ring or 6-membered ring in the fullerene skeleton. ³² ) ( ^R33 )-is added to form a 6-membered ring. In the general formula (n4), —C (R ³⁴ ) (R ³⁵ ) — is added to two adjacent carbon atoms on the same 5-membered ring or 6-membered ring in the fullerene skeleton to form a 3-membered ring. Forming. L is an integer of 1 to 8. L is preferably an integer of 1 to 4, more preferably an integer of 1 to 2.

R ²¹ in the general formula (n1) is an alkyl group having 1 to 14 carbon atoms which may have a substituent, an alkoxy group having 1 to 14 carbon atoms which may have a substituent, or a substituent. An aromatic group which may have a group.

  The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group or an isobutyl group, and even more preferably a methyl group or an ethyl group. .

  The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 6 carbon atoms, and particularly preferably a methoxy group or an ethoxy group.

  The aromatic group is preferably an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms, more preferably a phenyl group, a thienyl group, a furyl group, or a pyridyl group. A group or a thienyl group is more preferred.

  Although it does not specifically limit as a substituent which said alkyl group, an alkoxy group, and an aromatic group may have, A halogen atom or a silyl group is preferable.

  As the halogen atom, a fluorine atom is preferable.

  The silyl group is preferably a diarylalkylsilyl group, a dialkylarylsilyl group, a triarylsilyl group or a trialkylsilyl group, more preferably a dialkylarylsilyl group, and even more preferably a dimethylarylsilyl group.

R ^{22 to} R ²⁴ in the general formula (n1) may each independently have a hydrogen atom, an alkyl group having 1 to 14 carbon atoms which may have a substituent, or a substituent. It is an aromatic group.

  As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, and a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, or an n-hexyl group is preferable. . The substituent that the alkyl group may have is preferably a halogen atom. As the halogen atom, a fluorine atom is preferable. The alkyl group substituted with a fluorine atom is preferably a perfluorooctyl group, a perfluorohexyl group or a perfluorobutyl group.

  The aromatic group is preferably an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms, more preferably a phenyl group, a thienyl group, a furyl group, or a pyridyl group. A group or a thienyl group is more preferred. The substituent that the aromatic group may have is not particularly limited, but is a fluorine atom, an alkyl group having 1 to 14 carbon atoms, a fluorinated alkyl group having 1 to 14 carbon atoms, or a carbon atom having 1 to 14 carbon atoms. An alkoxy group or an aromatic group having 3 to 10 carbon atoms is preferable, a fluorine atom or an alkoxy group having 1 to 14 carbon atoms is more preferable, and a methoxy group, an n-butoxy group, or a 2-ethylhexyloxy group is further preferable. When the aromatic group has a substituent, the number is not limited, but is preferably 1 or more and 3 or less, and more preferably 1. When the aromatic group has a plurality of substituents, the types of the substituents may be different, but are preferably the same.

R ^{25 to} R ²⁹ in the general formula (n2) may each independently have a hydrogen atom, an alkyl group having 1 to 14 carbon atoms which may have a substituent, or a substituent. It is an aromatic group.

  The alkyl group is preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, n-hexyl group or octyl group, and more preferably a methyl group. The substituent that the alkyl group may have is not particularly limited, but a halogen atom is preferable. As the halogen atom, a fluorine atom is preferable. The alkyl group substituted with a fluorine atom is preferably a perfluorooctyl group, a perfluorohexyl group or a perfluorobutyl group.

  As the aromatic group, an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms is preferable, a phenyl group or a pyridyl group is more preferable, and a phenyl group is further preferable. Although it does not specifically limit as a substituent which an aromatic group may have, Preferably they are a fluorine atom, a C1-C14 alkyl group, or a C1-C14 alkoxy group. The alkyl group may be substituted with a fluorine atom. More preferably, it is an alkoxy group having 1 to 14 carbon atoms, and more preferably a methoxy group. When it has a substituent, the number is not limited, but it is preferably 1 or more and 3 or less, more preferably 1. The types of substituents may be different, but are preferably the same.

Ar ¹ in the general formula (n3) is an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms, preferably A phenyl group, a naphthyl group, a biphenyl group, a thienyl group, a furyl group, a pyridyl group, a pyrimidyl group, a quinolyl group or a quinoxalyl group, more preferably a phenyl group, a thienyl group or a furyl group.

  Although there is no limitation as a substituent which may have, an amino group which may be substituted with a fluorine atom, a chlorine atom, a hydroxyl group, a cyano group, a silyl group, a boryl group or an alkyl group, having 1 to 14 carbon atoms An alkyl group, an alkoxy group having 1 to 14 carbon atoms, an alkylcarbonyl group having 2 to 14 carbon atoms, an alkylthio group having 1 to 14 carbon atoms, an alkenyl group having 2 to 14 carbon atoms, and 2 to 14 carbon atoms An alkynyl group, an ester group having 2 to 14 carbon atoms, an arylcarbonyl group having 3 to 20 carbon atoms, an arylthio group having 2 to 20 carbon atoms, an aryloxy group having 2 to 20 carbon atoms, and 6 or more carbon atoms An aromatic hydrocarbon group having 20 or less or a heterocyclic group having 2 to 20 carbon atoms is preferable, a fluorine atom, an alkyl group having 1 to 14 carbon atoms, 1 or less carbon atoms 1 An alkoxy group, having 2 to 14 ester groups carbons, an alkyl group or having 3 to 20 arylcarbonyl group carbons of 2 to 14 carbon atoms and more preferable. The alkyl group having 1 to 14 carbon atoms may be substituted with 1 or 2 or more fluorine atoms.

  The alkyl group having 1 to 14 carbon atoms is preferably a methyl group, an ethyl group or a propyl group. The alkoxy group having 1 to 14 carbon atoms is preferably a methoxy group, an ethoxy group, or a propoxy group. The alkylcarbonyl group having 1 to 14 carbon atoms is preferably an acetyl group. The ester group having 2 to 14 carbon atoms is preferably a methyl ester group or an n-butyl ester group. The arylcarbonyl group having 3 to 20 carbon atoms is preferably a benzoyl group.

  When it has a substituent, the number is not limited, but it is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less. When there are a plurality of substituents, the types may be different, but are preferably the same.

R ^{30 to} R ³³ in the general formula (n3) each independently have a hydrogen atom, an alkyl group which may have a substituent, an amino group which may have a substituent, or a substituent. It is an optionally substituted alkoxy group or an optionally substituted alkylthio group. R ³⁰ or R ³¹ may be bonded to any one of R ³² and R ³³ to form a ring. As a structure in the case of forming a ring, the structure shown to the general formula (n5) which is a bicyclo structure which the aromatic group condensed is mentioned, for example.

In the general formula (n5), f is synonymous with c, and Z ⁴ is two hydrogen atoms, an oxygen atom, a sulfur atom, an amino group, an alkylene group, or an arylene group. The alkylene group preferably has 1 to 2 carbon atoms. The arylene group preferably has 5 to 12 carbon atoms, and examples thereof include a phenylene group. The amino group may be substituted with an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group. The alkylene group is an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or 2 to 20 carbon atoms. The aromatic heterocyclic group may be substituted. The arylene group is an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or 2 to 20 carbon atoms. The aromatic heterocyclic group may be substituted.

  The structure represented by the formula (n5) is particularly preferably a structure represented by the following formula (n6) or formula (n7).

R ^{34 to} R ³⁵ in the general formula (n4) each independently have a hydrogen atom, an alkoxycarbonyl group, an alkyl group having 1 to 14 carbon atoms which may have a substituent, or a substituent. An aromatic group that may be present.

  The alkoxy group constituting the alkoxycarbonyl group is preferably an alkoxy group having 1 to 12 carbon atoms or a fluorinated alkoxy group having 1 to 12 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and a methoxy group. Ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, n-hexoxy group, octoxy group, 2-propylpentoxy group, 2-ethylhexoxy group, cyclohexylmethoxy group or benzyloxy group A methoxy group, an ethoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group or an n-hexoxy group is particularly preferable.

  As the alkyl group, a linear alkyl group having 1 to 8 carbon atoms is preferable, and an n-propyl group is more preferable. The substituent that the alkyl group may have is not particularly limited, but is preferably an alkoxycarbonyl group. The alkoxy group constituting the alkoxycarbonyl group is preferably an alkoxy group having 1 to 14 carbon atoms or a fluorinated alkoxy group, more preferably a hydrocarbon group having 1 to 14 carbon atoms, a methoxy group, an ethoxy group, n- Propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, n-hexoxy group, octoxy group, 2-propylpentoxy group, 2-ethylhexoxy group, cyclohexylmethoxy group or benzyloxy group are more preferable, methoxy group or n A butoxy group is particularly preferred.

  As the aromatic group, an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms is preferable, and a phenyl group, a biphenyl group, a thienyl group, a furyl group, or a pyridyl group is preferable. More preferred are a phenyl group and a thienyl group. The substituent that the aromatic group may have is preferably an alkyl group having 1 to 14 carbon atoms, a fluorinated alkyl group having 1 to 14 carbon atoms, or an alkoxy group having 1 to 14 carbon atoms. An alkoxy group having a number of 1 or more and 14 or less is more preferable, and a methoxy group or 2-ethylhexyloxy group is particularly preferable. When it has a substituent, the number is not limited, but it is preferably 1 or more and 3 or less, more preferably 1. The types of substituents may be different or the same, preferably the same.

As the structure of the general formula (n4), preferably R ³⁴ and R ³⁵ are both alkoxycarbonyl groups, R ³⁴ and R ³⁵ are both aromatic groups, or R ³⁴ is an aromatic group and R ^{And those in which 35} is a 3- (alkoxycarbonyl) propyl group.

  As the fullerene compound, one kind of the above compounds may be used, or a mixture of plural kinds of compounds may be used.

  In order to form a fullerene compound by a coating method, it is preferable that the fullerene compound itself can be applied in a liquid state, or that the fullerene compound is highly soluble in some solvent and can be applied as a solution. When the preferable range of solubility is raised, the solubility in toluene at 25 ° C. is usually 0.1% by mass or more, preferably 0.4% by mass or more, more preferably 0.7% by mass or more. A solubility of the fullerene compound of 0.1% by mass or more is preferable because the dispersion stability of the fullerene compound in the solution increases and aggregation, sedimentation, separation, and the like hardly occur.

  The solvent for dissolving the fullerene compound is not particularly limited as long as it is a nonpolar organic solvent, but a non-halogen solvent is preferable. Although it is possible to use a halogen-based solvent such as dichlorobenzene, an alternative is demanded from the viewpoint of environmental load. Examples of non-halogen solvents include non-halogen aromatic hydrocarbons. Of these, toluene, xylene, cyclohexylbenzene, and the like are preferable.

(Method for producing fullerene compound)
Although there is no restriction | limiting in particular as a manufacturing method of a fullerene compound, For example, the synthesis | combination of the fullerene compound which has a partial structure (n1) is international publication 2008/059771 or J.N. Am. Chem. Soc. 2008, 130, 15429. It can implement according to description of well-known literature like.

  Synthesis of fullerene compounds having a partial structure (n2) is described in J. Org. Am. Chem. Soc. 1993, 115, 9798. Chem. Mater. 2007, 19, 5363. , And Chem. Mater. 2007, 19, 5194. It can implement according to description of well-known literature like.

  Synthesis of a fullerene compound having a partial structure (n3) is described in Angew. Chem. Int. Ed. 1993, 32, 78. Tetrahedron Lett. 1997, 38, 285. , And can be carried out in accordance with the descriptions of known documents such as International Publication No. 2008/018931 and International Publication No. 2009/086212.

  Synthesis of fullerene compounds having a partial structure (n4) is described in J. Org. Chem. Soc. Perkin Trans. 1997, 1, 1595. , Thin Solid Films 2005, 489, 251. Adv. Funct. Mater. 2005, 15, 1979. , And J.A. Org. Chem. 1995, 60, 532. It can implement according to description of well-known literature like.

<7.4.2.2. N-alkyl-substituted perylene diimide derivatives>
N-alkyl-substituted perylene diimide derivatives are not particularly limited, and specifically, International Publication No. 2008/063609, International Publication No. 2009/115553, International Publication No. 2009/098250, International Publication No. Examples thereof include compounds described in 2009/000756 and International Publication No. 2009/091670. These compounds are preferable in that they have high electron mobility and can absorb light in the visible range, and thus can contribute to both charge transport and power generation.

<7.4.2.3. Naphthalenetetracarboxylic acid diimide>
The naphthalenetetracarboxylic acid diimide is not particularly limited, and specific examples thereof include compounds described in International Publication No. 2008/063609, International Publication No. 2007/146250 and International Publication No. 2009/000756. It is done. These compounds are preferable because they have high electron mobility, high solubility, and excellent coating properties.

<7.4.2.4. n-type Polymer Semiconductor Compound>
There are no particular restrictions on the n-type polymer semiconductor compound, but condensed ring tetracarboxylic acid diimides such as naphthalenetetracarboxylic acid diimide and perylenetetracarboxylic acid diimide, perylene diimide derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazoles N-type polymer semiconductor comprising at least one of a derivative, a benzothiazole derivative, a benzothiadiazole derivative, an oxadiazole derivative, a thiadiazole derivative, a triazole derivative, a pyrazine derivative, a phenanthroline derivative, a quinoxaline derivative, a bipyridine derivative and a borane derivative Compounds.

  Among them, a polymer having at least one of a borane derivative, a thiazole derivative, a benzothiazole derivative, a benzothiadiazole derivative, an N-alkyl-substituted naphthalenetetracarboxylic acid diimide and an N-alkyl-substituted perylene diimide derivative as a constituent unit is provided. Preferably, an n-type polymer semiconductor compound having at least one of N-alkyl-substituted perylene diimide derivative and N-alkyl-substituted naphthalenetetracarboxylic acid diimide as a constituent unit is more preferable. One of the above compounds may be used as the n-type polymer semiconductor compound, or a mixture of a plurality of compounds may be used.

  Specific examples of the n-type polymer semiconductor compound include compounds described in International Publication No. 2009/098253, International Publication No. 2010/012710, and International Publication No. 2009/098250. Since these compounds can absorb light in the visible range, they can contribute to power generation, are preferred because of their high viscosity and excellent coating properties.

<7.4.2.5. n-Type Metal Oxide Semiconductor Compound>
The n-type metal oxide semiconductor compound is not particularly limited, and examples thereof include titanium oxide, zinc oxide, doped titanium oxide, and doped zinc oxide. These compounds are preferably high in electron mobility. In addition, the metal oxide manufactured with the manufacturing method of the metal oxide content layer which concerns on this invention can also be used as an n-type semiconductor.

<7.5. Method for manufacturing photoelectric conversion element>
A photoelectric conversion element can be manufactured by forming each layer which comprises a photoelectric conversion element in accordance with the method as described above.

  Each layer constituting the photoelectric conversion element according to the present invention is not particularly limited, and can be formed by a sheet-to-sheet (manyoba) system or a roll-to-roll system.

  The roll-to-roll method is a method in which a flexible base material wound in a roll shape is fed out and processed intermittently or continuously while being wound up by a take-up roll. is there. According to the roll-to-roll method, it is possible to batch-process long substrates of the order of km, so that the production method is more suitable for mass production than the sheet-to-sheet method.

  On the other hand, when each layer is formed by the roll-to-roll method, the film may be damaged or partially peeled due to contact between the film formation surface and the roll. However, in the present invention, since the film hardness of the metal oxide-containing layer is high, even when the film formation surface and the roll come into contact with each other, problems such as damage to the film or peeling off of the film are less likely to occur. Therefore, an electronic device can be manufactured with high productivity.

  The size of the roll that can be used in the roll-to-roll system is not particularly limited as long as it can be handled by a roll-to-roll manufacturing apparatus, but the upper limit of the outer diameter is usually 5 m or less, preferably 3 m or less, more preferably 1 m or less. On the other hand, the lower limit is usually 10 cm or more, preferably 20 cm or more, more preferably 30 cm or more. The upper limit of the outer diameter of the roll core is usually 4 m or less, preferably 3 m or less, more preferably 0.5 m or less. On the other hand, the lower limit is usually 1 cm or more, preferably 3 cm or more, more preferably 5 cm or more, further preferably 10 cm or more, and particularly preferably 20 cm or more. When these diameters are not more than the above upper limit, it is preferable in terms of high handleability of the roll, and when it is more than the lower limit, the layer formed in each of the following steps is less likely to be broken by bending stress. Is preferable. The lower limit of the width of the roll is usually 5 cm or more, preferably 10 cm or more, more preferably 20 cm or more. On the other hand, the upper limit is usually 5 m or less, preferably 3 m or less, more preferably 2 m or less. When the width is not more than the upper limit, it is preferable from the viewpoint of high handleability of the roll.

  In addition, after laminating the anode or the cathode, the photoelectric conversion element is usually 50 ° C. or higher, preferably 80 ° C. or higher, and usually 300 ° C. or lower, preferably 280 ° C. or lower, more preferably 250 ° C. or lower. It is preferable to heat (this step may be referred to as an annealing treatment step). By performing the annealing treatment step at a temperature of 50 ° C. or more, an effect of improving the adhesion between the layers of the photoelectric conversion element, for example, the adhesion between the electron extraction layer and the cathode, the electron extraction layer and the active layer, or the like can be obtained. Therefore, it is preferable. By improving the adhesion between the layers, the thermal stability and durability of the photoelectric conversion element can be improved. It is preferable to set the temperature of the annealing treatment step to 300 ° C. or lower because the possibility that the organic compound in the active layer is thermally decomposed is reduced. In the annealing treatment step, stepwise heating may be performed within the above temperature range.

  The heating time is usually 1 minute or longer, preferably 3 minutes or longer, and usually 180 minutes or shorter, preferably 60 minutes or shorter. The annealing treatment step is preferably terminated when the open-circuit voltage, the short-circuit current, and the fill factor, which are parameters of the solar cell performance, reach a constant value. Further, the annealing treatment step is preferably performed under normal pressure and in an inert gas atmosphere in order to prevent thermal oxidation of the constituent materials.

  As a heating method, the photoelectric conversion element may be placed on a heat source such as a hot plate, or the photoelectric conversion element may be placed in a heating atmosphere such as an oven. The heating may be performed batchwise or continuously.

<7.6. Photoelectric conversion characteristics>
The photoelectric conversion characteristics of the photoelectric conversion element 107 can be obtained as follows. The photoelectric conversion element 107 is irradiated with light having an AM 1.5G condition with a solar simulator at an irradiation intensity of 100 mW / cm ² , and current-voltage characteristics are measured. From the obtained current-voltage curve, photoelectric conversion characteristics such as photoelectric conversion efficiency (PCE), short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF), series resistance, and shunt resistance can be obtained.

  The photoelectric conversion efficiency of the photoelectric conversion element according to the present invention is not particularly limited, but is usually 1% or more, preferably 1.5% or more, more preferably 2% or more. On the other hand, there is no particular limitation on the upper limit, and the higher the better.

Moreover, as a method for measuring the durability of the photoelectric conversion element, a method for obtaining a maintenance ratio of the photoelectric conversion efficiency before and after exposing the photoelectric conversion element to the atmosphere can be mentioned.
(Maintenance rate) = (Photoelectric conversion efficiency after N hours of atmospheric exposure) / (Photoelectric conversion efficiency immediately before atmospheric exposure)

  In order to put a photoelectric conversion element into practical use, it is important to have high photoelectric conversion efficiency and high durability in addition to simple and inexpensive manufacture. From this viewpoint, the maintenance rate of photoelectric conversion efficiency before and after exposure to the atmosphere for one week is preferably 60% or more, more preferably 80% or more, and the higher the better.

<8. Solar cell>
The photoelectric conversion element 107 according to the present invention is preferably used as a solar cell, particularly a solar cell element of a thin film solar cell.

  FIG. 4 is a cross-sectional view schematically showing the configuration of a thin film solar cell as one embodiment of the present invention. As shown in FIG. 4, the thin film solar cell 14 of this embodiment includes a weather-resistant protective film 1, an ultraviolet cut film 2, a gas barrier film 3, a getter material film 4, a sealing material 5, and a solar cell element. 6, the sealing material 7, the getter material film 8, the gas barrier film 9, and the back sheet 10 are provided in this order. And light is irradiated from the side (downward in Drawing 4) in which weatherproof protective film 1 was formed, and solar cell element 6 generates electricity. Note that the thin-film solar cell does not need to have all of these constituent members, and each constituent member may be arbitrarily selected and provided.

  There are no particular restrictions on these constituent members constituting the thin-film solar cell and the manufacturing method thereof, and well-known techniques can be used. For example, the thing described in well-known literatures, such as international publication 2013/180230 or Unexamined-Japanese-Patent No. 2012-191194, can be used.

  There is no restriction | limiting in the use of the solar cell which concerns on this invention, especially the thin film solar cell 14 mentioned above, It can use for arbitrary uses. For example, solar cells for building materials, solar cells for automobiles, solar cells for interiors, solar cells for railways, solar cells for ships, solar cells for airplanes, solar cells for spacecrafts, solar cells for home appliances, solar cells for mobile phones, or toys For solar cells.

  The solar cell according to the present invention, particularly a thin-film solar cell, may be used as it is, or for example, a solar cell may be installed on a substrate and used as a solar cell module. For example, as shown in FIG. 5, the solar cell module 13 including the thin film solar cell 14 on the base 12 can be installed and used at a place of use. For the substrate 12, a well-known technique can be used, for example, those described in International Publication No. 2013/180230 or Japanese Patent Application Laid-Open No. 2012-191194 can be used. For example, when a building material plate is used as the substrate 12, a solar cell panel for an outer wall of a building can be produced as the solar cell module 13 by providing the thin film solar cell 14 on the surface of the plate.

  Hereinafter, embodiments of the present invention will be described by way of examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

<Decomposition temperature (Td)>
The decomposition temperature in the powder state of various compounds was measured by differential thermal mass simultaneous analysis using TG-DTA6300 manufactured by SII Nanotechnology. The measurement conditions are as follows.
Sample container: Aluminum sample container Atmosphere: Air 200 mL / min Temperature rising rate: 10 ° C./min Temperature range: 25 ° C. to 600 ° C.

The measured decomposition temperatures were as follows.
Zinc diacrylate (Nippon Shokubai Co., Ltd.): 228 ° C
Zinc acetate dihydrate (Wako Pure Chemical Industries, Ltd.): 242 ° C (dehydration 89 ° C)
Zinc acetylacetonate complex (manufactured by Dojindo Laboratories): 116 ° C
Polyvinyl butyral (Sekisui Chemical Co., Ltd. ESREC BM-1): 371 ° C
Polyvinyl butyral (Sekisui Chemical Co., Ltd. ESREC BH-A): 328 ° C
Polyvinyl acetoacetal (Eslek KS-1 manufactured by Sekisui Chemical Co., Ltd.): 363 ° C

  From the above, it was found that the decomposition temperature of zinc dicarboxylate is 200 ° C. or higher and lower than 300 ° C., which is higher than that of zinc acetylacetonate complex. Thus, it has been found that zinc dicarboxylate is usually stable, and zinc dicarboxylate cannot be converted into zinc oxide unless control is performed to positively apply external stimuli such as water and heat. In addition, it was found that the polyvinyl acetal resin has a decomposition temperature higher than that of zinc diacrylate by 100 ° C. or more, and it was found that the polyvinyl acetal resin is not decomposed at the stage of heat treatment in which the zinc diacrylate is converted to zinc oxide.

<Example 1: Preparation of metal oxide-containing layer forming composition and ink stability evaluation>
[Example 1-1]
Zinc diacrylate (Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd., ESREC BM-1, 27 mg) were mixed with ethanol (Wako Pure Chemical Industries, Ltd., 9.1 g) and toluene (Wako Pure). A colorless and transparent ink (S1) was prepared by dissolving in 0.3 g). When the ink (S1) was allowed to stand for 2 weeks in an uncontrolled air atmosphere (15 to 25 ° C., humidity 30 to 75%), no precipitate was visually observed. The results are shown in Table 1.

[Example 1-2]
Zinc diacrylate (Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd., ESREC BM-1, 135 mg) were mixed with ethanol (Wako Pure Chemical Industries, Ltd., 9.1 g) and toluene (Wako Pure). A colorless and transparent ink (S2) was prepared by dissolving in 0.3 g). When the ink (S2) was allowed to stand in an uncontrolled air atmosphere (15 to 25 ° C., humidity 30 to 75%) for 2 weeks, no precipitate was visually observed. The results are shown in Table 1.

[Example 1-3]
Zinc diacrylate (Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd., ESREC BH-A, 27 mg) were mixed with ethanol (Wako Pure Chemical Industries, Ltd., 9.1 g) and toluene (Wako Pure). A colorless and transparent ink (S3) was prepared by dissolving in 0.3 g). When the ink (S3) was allowed to stand in an uncontrolled air atmosphere (15 to 25 ° C., humidity 30 to 75%) for 2 weeks, no precipitate was visually observed. The results are shown in Table 1.

[Example 1-4]
Zinc diacrylate (Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyvinyl acetoacetal (Sekisui Chemical Co., Ltd., ESREC KS-1, 27 mg) were added to ethanol (Wako Pure Chemical Industries, Ltd., 9.1 g) and toluene (Japanese A colorless and transparent ink (S4) was prepared by dissolving in Kogaku Pharmaceutical Co., Ltd. (0.3 g). When the ink (S4) was allowed to stand for 2 weeks in an uncontrolled air atmosphere (15 to 25 ° C., humidity 30 to 75%), no precipitate was visually observed. The results are shown in Table 1.

[Comparative Example 1-1]
Zinc acetate dihydrate (Wako Pure Chemical Industries, 1760 mg, 8.0 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd., ESREC BM-1, 75 mg), ethanolamine (Aldrich, 0.50 mL) and A colorless transparent ink (S5), which is a zinc oxide precursor solution, was prepared by dissolving in 2-methoxyethanol (Aldrich, 10 mL) and stirring at 60 ° C. for 3 hours. When this ink (S5) was allowed to stand in an uncontrolled air atmosphere as in Example 1-1, a precipitate was visually confirmed after one week. The results are shown in Table 1.

[Comparative Example 1-2]
Zinc acetylacetonate complex (Donjin Chemical Laboratory Co., Ltd., 400 mg, 1.42 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd. ESREC BM-1, 13 mg) are dissolved in ethanol (Wako Pure Chemical Industries, Ltd., 10 mL). As a result, a colorless and transparent ink (S6) was prepared. When this ink (S6) was allowed to stand in an uncontrolled air atmosphere in the same manner as in Example 1-1, a precipitate was visually confirmed after 2 days. The results are shown in Table 1.

[Comparative Example 1-3]
Zinc oxide ethanol dispersion (manufactured by Aldrich, catalog number 721085) diluted 10 times with ethanol (manufactured by Wako Pure Chemical Industries, Ltd.) in 10 g (zinc oxide 4.91 mmol) was added to polyvinyl butyral (Sekisui Chemical Co., Ltd. BM-1, 46 mg) was added to prepare a white ink (S7). When this ink (S7) was allowed to stand in an uncontrolled air atmosphere as in Example 1-1, a precipitate was visually confirmed from the next day. The results are shown in Table 1.

  In Table 1, “◯” in the column of ink stability indicates precipitation in the ink after standing for 2 weeks in an uncontrolled atmosphere (15 to 25 ° C., humidity 30 to 75%). No matter was confirmed, and “x” means that a precipitate was confirmed in the ink under the same conditions.

  From the results of Table 1, it can be seen that the metal oxide-containing layer forming composition (ink) according to the present invention has high ink stability. The reason is considered that zinc diacrylate and polyvinyl acetal resin continue to dissolve stably without being decomposed in the ink.

<Example 2: Deposition of zinc oxide-containing layer in humidity atmosphere and applicability evaluation>
[Example 2-1]
A colorless and transparent ink (S1) was prepared in the same manner as in Example 1-1. Next, 0.3 mL of the prepared ink (S1) was dropped on a PEN (polyethylene naphthalate) film “Teonex Q65” manufactured by Teijin DuPont Films, Ltd. of A4 size, and then an automatic coating apparatus PI-1210 (manufactured by Tester Sangyo Co., Ltd.) Application | coating was carried out by air | atmosphere atmosphere (20 degreeC, 30% of humidity) using the bar number 10, speed 5). Thereafter, a colorless and transparent zinc oxide-containing layer was formed by heat treatment at 150 ° C. for 10 minutes in an air atmosphere, and the presence or absence of pores in the zinc oxide-containing layer was confirmed. The obtained results are shown in Table 2.

[Example 2-2]
A colorless and transparent zinc oxide-containing layer was formed by the method of Example 2-1 except that coating was performed in an air atmosphere (23 ° C., humidity 70%), and the presence or absence of pores was confirmed visually. The obtained results are shown in Table 2.

[Example 2-3]
Colorless and transparent zinc oxide contained in the same manner as in Example 2-2, except that the colorless and transparent ink (S3) prepared by the same method as in Example 1-3 was used instead of the ink (S1). A layer was formed, and the presence or absence of pores was visually confirmed. The obtained results are shown in Table 2.

[Example 2-4]
Colorless and transparent zinc oxide contained in the same manner as in Example 2-2, except that the colorless and transparent ink (S4) prepared by the same method as in Example 1-4 was used instead of the ink (S1). A layer was formed, and the presence or absence of pores was visually confirmed. The obtained results are shown in Table 2.

[Comparative Example 2-1]
By dissolving zinc diacrylate (Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) in ethanol (Wako Pure Chemical Industries, Ltd., 9.1 g) and toluene (Wako Pure Chemical Industries, Ltd., 0.3 g), it is colorless. A transparent ink (S8) was prepared. Next, 0.3 mL of the prepared ink (S8) was dropped on a PEN (polyethylene naphthalate) film “Teonex Q65” manufactured by Teijin DuPont Films of A4 size, and then an automatic coating apparatus PI-1210 (manufactured by Tester Sangyo Co., Ltd.) Application was performed under a controlled atmosphere (25 ° C., 30% humidity) using a bar number 10, speed 5). Thereafter, a colorless and transparent zinc oxide-containing layer having no visible holes was formed by heat treatment at 150 ° C. for 10 minutes in the atmosphere. The results are shown in Table 2.

[Comparative Example 2-2]
A zinc oxide-containing layer was formed by the same method as in Comparative Example 2-1, except that the coating was performed in an air atmosphere (20 ° C., humidity 30%), and the presence or absence of pores was visually confirmed. The obtained results are shown in Table 2. In addition, although the zinc oxide containing layer was formed 3 times, it has confirmed that there existed several holes with a hole diameter of about 1 mm or less in any metal oxide containing layer.

[Comparative Example 2-3]
Except that the coating was performed in an air atmosphere (23 ° C., humidity 70%), the formation of the zinc oxide-containing layer was attempted three times in the same manner as in Comparative Example 2-1, but all of the inks (S8) were PEN. It was repelled by the film and a zinc oxide-containing layer could not be formed.

[Example 2-5]
A colorless and transparent ink (S1) was prepared in the same manner as in Example 1-1. Next, 1 mL of the prepared ink (S1) was dropped on a substrate on which silver was deposited on a non-alkali glass (Corning 1737) with a thickness of 50 nm, and then a spin coater ACT-300DII (manufactured by Active) was used. Then, spin coating was performed at 3000 rpm × 30 seconds in an air atmosphere (22 ° C., humidity 62%). Thereafter, a colorless and transparent zinc oxide-containing layer having a film thickness of 80 nm was formed by performing heat treatment at 150 ° C. for 10 minutes in an air atmosphere, and the presence or absence of pores was confirmed. The obtained results are shown in Table 2.

[Comparative Example 2-4]
A metal with a film thickness of 60 nm was prepared in the same manner as in Example 2-5, except that the colorless and transparent ink (S8) prepared in the same manner as in Comparative Example 2-1 was used instead of the ink (S1). An oxide-containing layer was formed and the presence or absence of pores was confirmed. The obtained results are shown in Table 2, and a zinc oxide-containing layer was formed three times, but it was confirmed that each zinc oxide-containing layer had a plurality of holes having a diameter of about 0.5 mm or less. It was done.

  “◯” in the column of applicability in Table 2 means that no pores were present in the zinc oxide-containing layer visually. “Δ” means that pores are present in the zinc oxide-containing layer visually. “X” means that the zinc oxide-containing layer could not be formed.

  From the results of Table 2, it can be seen that the metal oxide-containing layer forming composition (ink) according to the present invention has high coating properties regardless of humidity. In particular, even when formed by a spin coat method in which solvent drying is performed together with film formation, good results were obtained by using the metal oxide-containing layer forming composition according to the present invention to increase productivity. It shows that a metal oxide-containing layer can be formed. On the other hand, when the polyvinyl acetal resin is not used, it can be seen that the applicability is unstable due to a change in humidity. The reason why the coating property of the composition for forming a metal oxide-containing layer according to the present invention is high may be that the polyvinyl acetal resin has moderately controlled the hydrophilicity and hydrophobicity with the underlying layer.

<Example 3: Pencil hardness test of zinc oxide-containing layer>
[Example 3-1]
The pencil hardness of the PEN film on which the zinc oxide-containing layer produced in the same manner as in Example 2-2 was formed was evaluated using a continuous load type scratch strength tester Heidon Type 18 (manufactured by Shinto Kagaku Co.). The obtained results are shown in Table 3.

[Comparative Example 3-1]
The pencil hardness of the PEN film produced in the same manner as in Comparative Example 2-1 and formed with the zinc oxide-containing layer was evaluated by the same method as in Example 3-1. The obtained results are shown in Table 3.

[Example 3-2]
A colorless and transparent ink (S1) was prepared in the same manner as in Example 1-1. Next, 1 mL of the prepared ink (S1) was dropped on an alkali-free glass substrate (Corning 1737), and then used in an air atmosphere (20 ° C., humidity 50) using a spin coater ACT-300DII (Active). %) At 8000 rpm × 30 seconds. Then, the colorless and transparent zinc oxide content layer was able to be produced by film thickness 50nm by performing heat processing for 10 minutes at 150 ° C under air atmosphere. The pencil hardness of the glass substrate on which the zinc oxide-containing layer was formed was evaluated using a continuous load type scratch strength tester Heidon Type 18 (manufactured by Shinto Kagaku Co.). The obtained results are shown in Table 3.

[Example 3-3]
Instead of ink (S1), zinc diacrylate (Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd., ESREC BM-1, 14 mg) were added with ethanol (Wako Pure Chemical Industries, Ltd., 9 0.1 g) and toluene (manufactured by Wako Pure Chemical Industries, Ltd., 0.3 g), except that a colorless and transparent ink (S9) prepared by adjusting the same was used, and the same procedure as in Example 3-2 was performed on the glass substrate. A colorless and transparent zinc oxide-containing layer having a film thickness of 45 nm was formed and the pencil hardness was evaluated. The obtained results are shown in Table 3.

[Example 3-4]
Instead of the ink (S1), zinc diacrylate (manufactured by Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd. ESREC BM-1, 7 mg) were added with ethanol (manufactured by Wako Pure Chemical Industries, Ltd., 9 0.1 g) and a colorless and transparent ink (S10) prepared by dissolving in toluene (manufactured by Wako Pure Chemical Industries, Ltd., 0.3 g) and using a colorless and transparent ink (S10), a film is formed on a glass substrate. A colorless and transparent zinc oxide-containing layer having a thickness of 43 nm was formed, and pencil hardness was evaluated. The obtained results are shown in Table 3.

[Comparative Example 3-2]
A colorless and transparent ink (S8) was prepared in the same manner as in Comparative Example 2-1. 1 mL of the prepared ink (S8) was dropped on a glass substrate, and then spin-coated at 4000 rpm × 30 seconds in an air atmosphere (20 ° C., humidity 50%) using a spin coater ACT-300DII (manufactured by Active). Thereafter, a 50 nm-thick zinc oxide-containing layer was formed by performing heat treatment at 150 ° C. for 10 minutes in an air atmosphere, and pencil hardness was evaluated. The obtained results are shown in Table 3.

[Comparative Example 3-3]
Zinc diacrylate (Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyethylene glycol (Aldrich PEG 10000, 27 mg) were mixed with ethanol (Wako Pure Chemical Industries, 9.1 g) and toluene (Wako Pure Chemical Industries, Ltd., A colorless and transparent ink (S11) was prepared by dissolving in 0.3 g). 1 mL of the prepared ink (S11) was dropped on a glass substrate, and then spin-coated at 6000 rpm × 30 seconds in an air atmosphere (20 ° C., humidity 50%) using a spin coater ACT-300DII (manufactured by Active). Then, the colorless and transparent zinc oxide content layer was able to be produced by film thickness 50nm by performing heat processing for 10 minutes at 150 ° C under air atmosphere. The pencil hardness of the glass substrate on which the zinc oxide-containing layer was formed was evaluated by the same method as in Example 3-2. The obtained results are shown in Table 3.

[Comparative Example 3-4]
A white ink (S7) was prepared in the same manner as in Comparative Example 1-3. 1 mL of the prepared ink (S7) was dropped on a glass substrate, and then spin-coated at 6000 rpm × 30 seconds in an air atmosphere (20 ° C., humidity 50%) using a spin coater ACT-300DII (manufactured by Active). Then, by performing heat treatment at 150 ° C. for 10 minutes in an air atmosphere, a white zinc oxide-containing layer having a thickness of 50 nm was formed, and pencil hardness was evaluated. The obtained results are shown in Table 3.

[Comparative Example 3-5]
A white ink (S12) was prepared by diluting a zinc oxide ethanol dispersion (manufactured by Aldrich, catalog number 72085) 10 times with ethanol (manufactured by Wako Pure Chemical Industries, Ltd.). 1 mL of the prepared ink (S12) was dropped on a glass substrate, and then spin-coated at 4000 rpm × 30 seconds in an air atmosphere (20 ° C., humidity 50%) using a spin coater ACT-300DII (manufactured by Active). Thereafter, a heat treatment was performed at 150 ° C. for 10 minutes in an air atmosphere to form a white zinc oxide-containing layer having a thickness of 50 nm, and pencil hardness was evaluated. The obtained results are shown in Table 3.

  In Table 3, the content (mass%) of the binder resin in the zinc oxide-containing layer is that all the zinc compounds in the zinc oxide-containing layer forming composition are converted to zinc oxide, and the binder resin in the composition is decomposed. Without calculation, the ratio of the composition was calculated under the assumption that no solvent remained in the layer.

  From the results in Table 3, it can be seen that the metal oxide-containing layer formed using the metal oxide-forming composition according to the present invention has a high pencil hardness and a moderately high film hardness. Therefore, in the roll-to-roll method, even if the metal oxide-containing layer is formed, it can be expected that the film is not damaged. In addition, the reason why the pencil hardness of the metal oxide-containing layer according to the present invention is high is that when the metal oxide-containing layer is formed, the particle size of zinc oxide generated from zinc diacrylate is controlled by the polyvinyl acetal resin. Furthermore, it is considered that this is because the zinc oxide particles are appropriately bonded.

<Example 4: Visible / ultraviolet spectrum (UV-Vis) spectrum of zinc oxide-containing layer>
[Example 4-1]
Using a spectrophotometer U-4100 (manufactured by Hitachi High-Tech), visible / ultraviolet spectrum (UV) of a glass substrate on which a zinc oxide-containing layer (film thickness 50 nm) formed by the same method as in Example 3-2 was formed. -Vis) was measured in the wavelength range of 240-600 nm. The obtained visible / ultraviolet spectrum (UV-Vis) results are shown in FIG.

(Measurement condition)
Model name: U-4100
Measurement mode: Wavelength scan data mode: Abs
Starting wavelength: 600nm
End wavelength: 240nm
Scan speed: 600nm / min
Number of measurements: 1
Slit: 5nm
Light source switching mode: Automatic switching Light source switching wavelength: 340 nm

[Comparative Example 4-1]
The visible / ultraviolet spectrum (UV-Vis) of a 50 nm-thickness zinc oxide-containing layer formed on the substrate by the same method as in Comparative Example 3-2 was measured by the same method as in Example 4-1. The obtained results are shown in FIG. In addition, although the metal oxide containing layer obtained by Comparative Example 3-2 had pores of about 0.5 mm or less in the layer, the spectrum measurement was performed avoiding these holes during the spectrum measurement. The obtained result is shown in FIG.

  From the results shown in FIG. 6, it can be confirmed that at the same film thickness, the zinc oxide-containing layer containing the polyvinyl acetal resin has a larger spectrum derived from zinc oxide. The reason for this is considered to be that the crystallinity is appropriately increased by controlling the particle diameter of zinc oxide produced from zinc diacrylate due to the presence of the polyvinyl acetal resin.

<Example 5: Production and evaluation of photoelectric conversion element>
[Synthesis Example 1: Synthesis of copolymer]

  Under a nitrogen atmosphere, 1,3-dibromo-5- (n-) obtained in a 50 mL two-necked eggplant flask as a monomer with reference to a method described in a known document (Organic Letters 2004, 6, 3381-3384). Octyl) -4H-thieno [3,4-c] pyrrole-4,6- (5H) -dione (Compound F1, 343 mg, 0.811 mmol), reference to known literature (Polymer, 1990, 31, 1379-1383) 4,4′-didodecyl-5,5′-bis (trimethylstannyl) -2,2′-bithiophene (compound T1, 336 mg, 0.406 mmol) obtained in the above, and the method described in WO2013 / 180243 4,4-Dioctyl-2,6-bis (trimethyltin) -dithieno [3,2-b: 2 ′ obtained by reference , 3′-d] silole (compound E1, 302 mg, 0.406 mmol), tetrakis (triphenylphosphine) palladium (0) (23.4 mg, 2.5 mol%), triphenylphosphine-containing heterogeneous palladium A complex catalyst Pd-EnCatTPP30 (Aldrich, 36.5 mg, 3 mol%), toluene (24 mL), and N, N-dimethylformamide (6 mL) were added, and the mixture was stirred at 90 ° C. for 1 hour and then at 100 ° C. for 10 hours. did. After the reaction solution was diluted 4-fold with toluene and heated and stirred at 100 ° C. for another 0.5 hours, as a terminal treatment, trimethyl (phenyl) tin (0.16 mL) was added and heated and stirred at 100 ° C. for 2 hours. Bromobenzene (8 mL) was further added, and the mixture was heated and stirred at 100 ° C. for 5 hours. The reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer was obtained in a yield of 83%. The weight average molecular weight Mw of the obtained copolymer was 66K, and PDI was 2.9.

The polystyrene-reduced weight average molecular weight (Mw) and number average molecular weight (Mn) were determined by gel permeation chromatography (GPC). Molecular weight distribution (PDI) represents Mw / Mn. Gel permeation chromatography (GPC) measurement was performed under the following conditions.
Column: PolymerLaboratories GPC column (PLgel MIXED-B 10 μm, inner diameter 7.5 mm, length 30 cm) 2 connected in series Pump: LC-10AT (manufactured by Shimadzu Corporation)
Oven: CTO-10A (manufactured by Shimadzu Corporation)
Detector: differential refractive index detector (manufactured by Shimadzu Corporation, RID-10A) and UV-vis detector (manufactured by Shimadzu Corporation, SPD-10A)
Sample: 1 μL of 1 mg sample dissolved in orthodichlorobenzene (200 mg)
Mobile phase: orthodichlorobenzene Flow rate: 1.0 mL / min
Temperature: 80 ° C
Analysis: LC-Solution (manufactured by Shimadzu Corporation)

[Preparation of organic active layer coating solution]
The copolymer obtained in Synthesis Example 1 and a mixture of C ₆₀ PCBM and C ₇₀ PCBM (Nanom Spectra-E123 manufactured by Frontier Carbon Co., Ltd.) as an n-type semiconductor compound were mixed so that the mass ratio was 1: 2.5. The mixture was dissolved in a mixed solvent of orthoxylene and tetralin (volume ratio 9: 1) in a nitrogen atmosphere so that the mixture had a concentration of 3.2% by mass. This solution was stirred and mixed on a hot stirrer at a temperature of 80 ° C. for 1 hour. The solution after stirring and mixing was filtered through a polytetrafluoroethylene (PTFE) filter having a pore size of 1 μm to obtain an organic active layer coating solution.

[Example 5-1]
A colorless and transparent ink (S1) was prepared in the same manner as in Example 1-1.

  Next, the glass substrate on which a transparent conductive film of indium tin oxide (ITO) with a thickness of 155 nm is deposited is cleaned in the order of ultrasonic cleaning using acetone and ultrasonic cleaning using isopropanol, followed by nitrogen blowing. It was.

  After 1 mL of the ink (S1) prepared by the same method as in Example 1-1 was dropped on the cleaned substrate, the spin coater ACT-300DII (manufactured by Active Co., Ltd.) was used in an uncontrolled atmosphere (23 ° C. , Humidity 70%), spin coating at 6000 rpm for 30 seconds. Thereafter, a heat treatment at 150 ° C. for 10 minutes was performed to form an electron extraction layer composed of a zinc oxide-containing layer of about 55 nm.

  Subsequently, an organic active layer having a thickness of about 300 nm was formed on the electron extraction layer by spin coating the organic active layer coating solution in a nitrogen atmosphere using a spin coater MS-A100 (manufactured by Mikasa). . Then, it heated at 140 degreeC for 10 minute (s) using the hotplate.

Next, a molybdenum trioxide (MoO ₃ ) layer having a thickness of 5 nm was formed on the organic active layer by a resistance heating vacuum deposition method, thereby forming a hole extraction layer.

  Furthermore, a silver electrode having a thickness of 100 nm was formed on the hole extraction layer by a resistance heating vacuum deposition method, thereby producing a 5 mm square photoelectric conversion element.

Using a solar simulator with an air mass (AM) of 1.5 G and an irradiance of 100 mW / cm ² as the irradiation light source, the current-voltage characteristics of the produced photoelectric conversion element using a source meter 2400 (manufactured by Keithley Instruments) are shown as a 4 mm square metal mask. And measured. Table 4 shows the measurement results of the open circuit voltage Voc [V], the short circuit current density Jsc [mA / cm ² ], the form factor FF, and the photoelectric conversion efficiency PCE [%].

Here, the open circuit voltage Voc is the voltage value (V) when the current value = 0 (mA / cm ² ), and the short circuit current density Jsc is the current density when the voltage value = 0 (V) ( mA / cm ² ). The form factor (FF) is a factor representing the internal resistance, and is represented by the following expression when the maximum output point is Pmax.
FF = Pmax / (Voc × Jsc)
Further, the photoelectric conversion efficiency PCE is given by the following equation when the incident energy is Pin.
PCE = Pmax / Pin × 100
= Voc x Jsc x FF / Pin x 100

[Example 5-2]
Example 5 except that the colorless and transparent ink (S10) obtained by the same method as in Example 3-4 was used instead of the ink (S1), and the thickness of the electron extraction layer was 42 nm. The photoelectric conversion element of 5 mm square was produced by the method similar to -1, and the conversion efficiency was measured. Table 4 shows the obtained results.

[Example 5-3]
Example 5 except that the colorless and transparent ink (S9) obtained by the same method as in Example 3-3 was used instead of the ink (S1), and the film thickness of the electron extraction layer was 41 nm. The photoelectric conversion element of 5 mm square was produced by the method similar to -1, and the conversion efficiency was measured. Table 4 shows the obtained results.

[Example 5-4]
Instead of the ink (S1), zinc diacrylate (manufactured by Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd. ESREC BM-1, 54 mg) were added with ethanol (manufactured by Wako Pure Chemical Industries, Ltd., 9 .1 g) and toluene (manufactured by Wako Pure Chemical Industries, Ltd., 0.3 g) and using a colorless and transparent ink (S13) prepared and adjusted, except that the thickness of the electron extraction layer is 83 nm. A 5 mm square photoelectric conversion element was produced in the same manner as in Example 5-1, and the conversion efficiency was measured. Table 4 shows the obtained results.

[Example 5-5]
Instead of the ink (S1), zinc diacrylate (Nippon Shokubai Co., Ltd., 600 mg, 2.89 mmol) and polyvinyl butyral (Sekisui Chemical Co., Ltd., ESREC BM-1, 81 mg) were mixed with ethanol (Wako Pure Chemical Industries, 9 0.1 g) and toluene (manufactured by Wako Pure Chemical Industries, Ltd., 0.3 g), and using a colorless and transparent ink (S14) prepared and adjusted, except that the thickness of the electron extraction layer is 140 nm. A 5 mm square photoelectric conversion element was produced in the same manner as in Example 5-1, and the conversion efficiency was measured. Table 4 shows the obtained results.

[Example 5-6]
Instead of the ink (S1), using the ink (S2) obtained by the method of Example 1-2, and the thickness of the electron extraction layer is 140 nm, the same as in Example 5-1. A 5 mm square photoelectric conversion element was prepared by the method, and the conversion efficiency was measured. Table 4 shows the obtained results.

[Example 5-7]
Instead of the ink (S1), the ink (S4) obtained by the method of Example 1-4 was used, and the thickness of the electron extraction layer was 50 nm. A 5 mm square photoelectric conversion element was prepared, conversion efficiency was prepared, and conversion efficiency was measured. Table 4 shows the obtained results.

[Comparative Example 5-1]
The ink (S8) obtained by the method of Comparative Example 2-1 was used in place of the ink (S1), and coating was performed in a controlled atmosphere (25 ° C., humidity 10%), and 150 ° C. for 10 minutes. A 5 mm square photoelectric conversion element was prepared in the same manner as in Example 5-1, except that a 44 nm electron extraction layer was formed by the above treatment, and the conversion efficiency was measured. Table 4 shows the obtained results.

  The content (mass%) of the polyvinyl acetal resin in the zinc oxide-containing layer in Table 4 is that all the zinc diacrylate in the composition for forming a zinc oxide-containing layer is converted to zinc oxide, and the polyvinyl acetal in the composition Calculations were made from the composition ratios on the assumption that the resin did not decompose and no solvent remained in the layer.

  From the result of Table 4, when the polyvinyl acetal resin is contained in the metal oxide-containing layer, the voltage and FF are improved and the photoelectric conversion efficiency (PCE) is improved. From this result, it was considered that the polyvinyl acetal resin is insulative and the conduction path of individual electrons may be obstructed. However, the presence of the polyvinyl acetal resin improves the crystallinity of zinc oxide, and the oxidation. It is considered that the conduction path of electrons increased due to the improved contact between the zinc particles.

  From Examples 1 to 5 described above, the present invention provides a composition that can easily form a metal oxide-containing layer having high electrical characteristics and appropriate film hardness, an electronic device including the metal oxide-containing layer, and It can be said that a method for easily manufacturing the electronic device can be provided.

51 Semiconductor layer 52 Insulator layers 53 and 54 Source electrode and drain electrode 55 Gate electrode 56 Base material 31 Base material 32 Anode 33 Hole injection layer 34 Hole transport layer 35 Light emitting layer 36 Electron transport layer 37 Electron injection layer 38 Cathode 39 Electroluminescent device 101 Cathode 102 Electron extraction layer 103 Active layer 104 Hole extraction layer 105 Anode 106 Base material 107 Photoelectric conversion device 1 Weather-resistant protective film 2 UV cut film 3, 9 Gas barrier film 4, 8 Getter material film 5, 7 Sealing Stop material 6 Solar cell element 10 Back sheet 12 Base material 13 Solar cell module 14 Thin film solar cell

Claims (8)

A metal oxide-containing layer forming composition comprising an unsaturated carboxylic acid metal salt represented by the formula (I) and a polyvinyl acetal resin.

(In the formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom or an arbitrary substituent, M is an m-valent metal atom, and m is an integer of 2 or more and 5 or less. M m CR ¹ R ² ═CR ³ —COO ⁻ may be the same or different from each other.)   The metal oxide-containing layer forming composition according to claim 1, wherein the unsaturated carboxylic acid metal salt has 3 to 12 carbon atoms. ^3. The metal oxide-containing layer according to claim ¹ , wherein, in the formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom or an alkyl group which may have a substituent. Forming composition.   In the formula (I), M is any metal atom selected from a transition metal element in the fourth period of the periodic table, a group 12 element of the periodic table, a group 13 element of the periodic table, and a group 14 element of the periodic table. The composition for forming a metal oxide-containing layer according to any one of claims 1 to 3.   In the said formula (I), M is a zinc atom, The composition for metal oxide containing layer formation of any one of Claims 1-4.   It is a manufacturing method of the electronic device provided with the metal oxide content layer, Comprising: The manufacturing process of the said metal oxide content layer is a metal oxide content layer formation composition given in any 1 paragraph of Claims 1-5. The manufacturing method of the electronic device characterized by including the process of apply | coating and the process of heat-processing after the said application | coating.   The method of manufacturing an electronic device according to claim 6, wherein the electronic device is a photoelectric conversion element.   An electronic device having a metal oxide-containing layer containing a metal oxide and a polyvinyl acetal resin, wherein the content of the polyvinyl acetal resin in the metal oxide-containing layer is 1% by mass or more and 60% by mass or less. An electronic device characterized by being.

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