JP2016003302A - Composition, electronic device and method of producing electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for simply producing an electronic device comprising a metal-oxide-containing layer with high flexibility and high electric characteristics, and a composition that makes it possible to simply form a metal-oxide-containing layer.SOLUTION: A composition comprises metalalkoxide, α,β-unsaturated carboxylic acid, and solvent. The content of the α,β-unsaturated carboxylic acid to the metalalkoxide is 1 mol% or more and less than 200 mol%.

Description

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

  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. For example, Patent Document 1 describes an example of OPV using a titanium oxide-containing layer as a buffer layer.

  As a method for producing a titanium oxide-containing layer, in Patent Document 1, a composition containing titanium tetra (i-propoxide) and ethanolamine (hereinafter sometimes referred to as ink) is applied, and thereafter A method of performing heat treatment is described. Further, in Non-Patent Document 1, after applying an ink containing a reaction product of titanium tetra (i-propoxide) and 200 mol% or more of methacrylic acid with respect to titanium tetra (i-propoxide). A method of performing heat treatment and photocuring treatment is described.

International Publication No. 2009/025523

J. et al. Mater. Sci. 2013, 48, 7503-7509.

  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. In addition, for the practical application of organic semiconductor devices, it is one of the major problems that a metal oxide-containing layer having high electrical characteristics and high flexibility can be manufactured 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 Document 1 and Non-Patent Document 1, a metal oxide that achieves both high electrical characteristics and high flexibility. It has been found that it is difficult to obtain a containing layer.

  Specifically, the titanium oxide-containing layer obtained by the method described in Patent Document 1 contains ethanolamine that could not be removed by a process such as heat treatment, and thus it was found that high electrical characteristics were difficult to obtain. did. In addition, the metal oxide-containing layer obtained by the method described in Non-Patent Document 1 contains an excess of a methacrylic acid polymer due to photocuring treatment during the production process, and thus has high electrical characteristics and high flexibility. It has been found difficult to form a metal oxide-containing layer having In view of the above problems, the present invention provides a method for easily producing an electronic device including a metal oxide-containing layer having high electrical characteristics and high flexibility, and easily forming the metal oxide-containing layer. It is an object of the present invention to provide a composition that makes it possible.

  As a result of intensive studies in view of the above circumstances, the present inventors have solved the above-mentioned problems and achieved the present invention by using a composition having a specific composition.

That is, the gist of the present invention is as follows.
[1] A composition comprising a metal alkoxide, an α, β-unsaturated carboxylic acid, and a solvent,
Content of the said (alpha), (beta)-unsaturated carboxylic acid with respect to the said metal alkoxide is 1 mol% or more and less than 200 mol%, The composition characterized by the above-mentioned.
[2] The metal atom constituting the metal alkoxide is a metal atom selected from a transition metal element in the fourth 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 according to [1], which is characterized in that it exists.
[3] The composition according to [1] or [2], further containing one or more metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table.
[4] The total number of one or more metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table is 0 with respect to the metal atoms constituting the metal alkoxide. The composition according to any one of [1] to [3], which is 1 atomic% or more and 50 atomic% or less.
[5] The composition according to any one of [1] to [4], wherein the α, β-unsaturated carboxylic acid has 3 to 12 carbon atoms.
[6] The composition according to any one of [1] to [5], wherein the solvent is an alcohol.
[7] A method for producing an electronic device having a metal oxide-containing layer on a base material, the composition according to any one of [1] to [6] being applied on the base material, The manufacturing method of an electronic device including the process of forming the said metal oxide content layer by performing heat processing after application | coating.
[8] The method for manufacturing an electronic device according to [7], wherein the substrate is a resin substrate.
[9] The method for manufacturing an electronic device according to [7] or [8], wherein the heat treatment is performed at 30 ° C. or higher and lower than 300 ° C.
[10] An electronic device having a metal oxide-containing layer containing a metal oxide and an α, β-unsaturated carboxylic acid polymer, the α, β-unsaturated carboxylic acid in the metal oxide-containing layer An electronic device, wherein the acid polymer is 1% by mass or more and 40% by mass or less.
[11] An electronic device in which the electronic device according to [10] is a photoelectric conversion element.
[12] A solar cell comprising the electronic device according to [11].

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

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.

  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 done. 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, a method for forming a metal oxide-containing layer using the composition according to the present invention will be described.

<1. Composition>
The composition according to the present invention contains a metal alkoxide, an α, β-unsaturated carboxylic acid, and a solvent.

<1.1. Metal alkoxide>
Examples of the metal atom of the metal alkoxide include an atom that easily forms a metal alkoxide. 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. In addition, a transition metal element refers to the generic name of the metal element of 3rd group of the periodic table-11th group. Further, in this specification, the periodic table refers to a recommended version of IUPAC 2005 (Recommendations of IUPAC 2005).

  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 aluminum atom, a gallium atom, or an indium atom. The metal atom selected from Group 14 elements of the periodic table is preferably a germanium atom, a tin atom, or a lead atom. Among these, the titanium oxide, vanadium atom, iron atom, nickel atom, copper atom, zinc atom, aluminum atom, gallium atom, indium atom or tin from the point that the carrier mobility of the obtained metal oxide-containing layer is increased. An atom is preferable, and a titanium atom, a nickel atom, a copper atom, a zinc atom, an indium atom, or a tin atom is more preferable. Among these, a titanium atom is particularly preferable. When the metal atom constituting the metal alkoxide is a titanium atom, the titanium alkoxide is more stable than other metal alkoxides, and the obtained titanium oxide-containing layer is a film compared to other metal oxide-containing layers. There is a tendency for uniformity, physical properties and carrier mobility to be high. Note that in this specification, carrier mobility refers to either electron mobility or hole mobility, as will be described later.

  The alkoxy group of the metal alkoxide is not particularly limited, but the alcohol generated when the metal alkoxide is converted into the metal oxide in the step of forming the metal oxide-containing layer described later can be used at a temperature of less than 300 ° C. It is preferable to use a metal alkoxide that can be volatilized. Specifically, an alkoxy group having 1 to 12 carbon atoms is preferably used. For example, a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, t -Butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group, ethylhexyloxy group, cyclohexyloxy group, phenoxy group, 1-naphthyloxy group Or a benzyloxy group.

  Among these, it is preferable that it is a C1-C4 linear alkoxy group which can volatilize produced | generated alcohol at the temperature of 150 degrees C or less. Specific examples include a methoxy group, an ethoxy group, an n-propoxy group, and an n-butoxy group.

  In addition, when the metal atom of a metal alkoxide is bivalent or more, you may have 2 or more types of alkoxy groups.

  Moreover, the composition may contain 2 or more types of metal alkoxides.

  The total concentration of the metal alkoxide in the composition is not particularly limited, but is usually 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, and usually 99.9% by mass. %, More preferably 50% by mass or less, and particularly preferably 20% by mass or less. If the concentration of the metal alkoxide in the composition is within the above range, it is preferable in that it can be applied uniformly and a uniform metal oxide-containing layer can be obtained.

<1.2. α, β-unsaturated carboxylic acid>
As described above, the composition according to the present invention contains an α, β-unsaturated carboxylic acid. In the present invention, the α, β-unsaturated carboxylic acid means a carboxylic acid represented by the following general formula (1).

  The α, β-unsaturated carboxylic acid having a carboxyl group bonded to a carbon atom constituting a carbon-carbon double bond (C═C) has a property of stabilizing a metal alkoxide by a ligand action in the composition. Have. That is, the ink stability of the composition can be improved. In addition, it has a property of promoting the formation of a metal oxide as an acid catalyst for the hydrolysis reaction of a metal alkoxide during a heat treatment step in forming a metal oxide-containing layer described later. Furthermore, the α, β-unsaturated carboxylic acid polymer produced by the heat treatment step remains in an appropriate amount in the resulting metal oxide-containing layer, thereby contributing to an improvement in the flexibility of the layer obtained as a binder. There is a nature. From the above points, using a metal alkoxide and an α, β unsaturated carboxylic acid in combination as the composition is effective for forming a metal oxide-containing layer.

In formula (1), R ¹ , R ^2, and R ³ are not particularly limited as long as the resulting metal oxide-containing layer functions, and are each independently a hydrogen atom or a monovalent organic group.

  The monovalent organic group is not particularly limited, but preferred examples include a halogen atom, hydroxyl group, cyano group, nitro group, amino group, silyl group, boryl group, alkyl group, alkenyl group, alkynyl group, alkoxy group, Examples thereof include a carboxyl group, an alkoxycarbonyl group, an amide group, an aromatic hydrocarbon group, and an aromatic heterocyclic group. The amino group, silyl group, boryl group, alkyl group, alkenyl group, alkynyl group, alkoxy group, alkoxycarbonyl group, amide group, aromatic hydrocarbon group or aromatic heterocyclic group further has a substituent. May be.

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

  The amino group is not particularly limited, and examples thereof include a primary amino group, a secondary amino group, or a tertiary amino group having 20 or less carbon atoms. Examples of the secondary amino group and the tertiary amino group include aromatic substituted amino groups such as a diphenylamino group, a ditolylamino group, and a carbazolyl group.

  The silyl group is not particularly limited, but is preferably a primary silyl group, a secondary silyl group, a tertiary silyl group, or a quaternary silyl group having 20 or less carbon atoms. For example, a trimethylsilyl group, a triphenylsilyl group, etc. are mentioned.

  The boryl group is not particularly limited, but is preferably a primary boryl group, a secondary boryl group, or a tertiary boryl group having 20 or less carbon atoms. For example, an aromatic substituted boryl group such as a dimesitylboryl group can be mentioned.

  The alkyl group is not particularly limited but preferably has 1 to 20 carbon atoms. For example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group, or a cyclohexyl group can be given.

  The alkenyl group is not particularly limited, but preferably has 2 to 20 carbon atoms. For example, a vinyl group or a styryl group is mentioned.

  The alkynyl group is not particularly limited but preferably has 2 to 20 carbon atoms. For example, an ethynyl group, a phenylethynyl group, or a trimethylsilylethynyl group can be mentioned.

  The alkoxy group is not particularly limited but preferably has 2 to 20 carbon atoms. For example, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, t-butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy And linear or branched alkoxy groups such as a group, a decyloxy group, an undecyloxy group, a dodecyloxy group, an ethylhexyloxy group, a cyclohexyloxy group, a phenoxy group, a 1-naphthyloxy group, and a benzyloxy group.

  The alkoxycarbonyl group is not particularly limited but preferably has 2 to 20 carbon atoms. Examples thereof include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, and an octyloxycarbonyl group.

  The aromatic hydrocarbon group is not particularly limited, but preferably has 6 to 20 carbon atoms. 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. An example of the monocyclic aromatic hydrocarbon group is 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.

  The aromatic heterocyclic group is not particularly limited, but preferably has 2 to 20 carbon atoms. 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, or phenylcarbazolyl group Is mentioned. Among these, a pyridyl group, a thienyl group, a benzothienyl group, a dibenzofuryl group, a dibenzothienyl group, or a phenanthryl group is preferable.

  Substituents that the amino group, silyl group, boryl group, alkyl group, alkenyl group, alkynyl group, alkoxy group, alkoxycarbonyl group, aromatic hydrocarbon group or aromatic heterocyclic group may have are particularly limited. 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} ), fumaric acid mono octyl _{^{(R 1 = COOC 8 H 17}} , R 2 = R 3 = H), monomethyl maleate ^{(R 1 = H, R 2} = COOC ^_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), citraconic acid mono octyl (R ¹ = _{^{H 3, R 2 = COOC 8}} H 17, R 3 = H), mesaconic acid monomethyl _{^{(R 1 = COOCH 3, R}} 2 = CH 3, R 3 = H), mesaconic acid monoethyl (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.

  In the case where the metal oxide-containing layer is formed at a low temperature, it is preferable to use an α, β-unsaturated carboxylic acid having a low boiling point. Since the temperature at which the α, β-unsaturated carboxylic acid is likely to undergo polymerization is around the boiling point at which the molecules actively move, the α, β-unsaturated carboxylic acid according to the present invention includes α, β-unsaturated carboxylic acids are preferable, α, β-unsaturated carboxylic acids having a boiling point of 250 ° C. or lower are more preferable, and α, β-unsaturated carboxylic acids having a boiling point of 200 ° C. or lower are more preferable. 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.

  Moreover, it is preferable that the number of carbon atoms constituting the α, β-unsaturated carboxylic acid is small so that many unreacted substances derived from the unsaturated carboxylic acid do not remain in the formed metal oxide-containing layer. From this viewpoint, the number of carbon atoms of the α, β-unsaturated carboxylic acid is preferably 12 or less, more preferably 6 or less, and further preferably 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. Specific examples of more preferable 6 or less α, β-unsaturated carboxylic acids include acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, isocrotonic acid, angelic acid, tiglic acid, 2-pentenoic acid, 2-hexenoic acid, Examples include fumaric acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid, monomethyl fumarate, monoethyl fumarate, monomethyl maleate, monoethyl maleate, monomethyl itaconic acid, 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.

  In addition, the composition may contain 2 or more types of α, β-unsaturated carboxylic acids.

  The total concentration of the α, β-unsaturated carboxylic acid in the composition is not particularly limited, but is usually 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more. Usually, it is less than 99.9% by mass, more preferably 50% by mass or less, and particularly preferably 20% by mass or less. If the concentration of the α, β-unsaturated carboxylic acid metal salt in the composition is within the above range, it is preferable in that it can be applied uniformly and a uniform metal oxide-containing layer can be obtained. .

  In the composition, the α, β-unsaturated carboxylic acid is usually at least 1 mol%, preferably at least 3 mol%, more preferably at least 5 mol%, still more preferably at least 10 mol%, based on the metal alkoxide. More preferably, it is 20 mol% or more, and particularly preferably 25 mol% or more. On the other hand, if the amount of α, β-unsaturated carboxylic acid is too large relative to the metal alkoxide, the polymer of α, β-unsaturated carboxylic acid in the resulting metal oxide-containing layer will be too much, Electrical characteristics are significantly degraded. Therefore, with respect to the metal alkoxide, the α, β-unsaturated carboxylic acid is less than 200 mol%, preferably 175 mol% or less, more preferably 150 mol% or less, and particularly preferably 100 mol% or less. When the α, β-unsaturated carboxylic acid is within the above range with respect to the metal alkoxide, the composition is stable and a metal oxide-containing layer having high electrical characteristics and high flexibility can be obtained. This is preferable.

<1.3. Solvent>
The composition according to the present invention further contains a solvent.

  The solvent is not particularly limited, but for example, water; aliphatic hydrocarbons such as hexane, heptane, octane, isooctane, nonane, decane; aromatic hydrocarbons such as toluene, xylene, chlorobenzene, orthodichlorobenzene; methanol, Alcohols such as ethanol, isopropanol, 2-methoxyethanol, 2-butoxyethanol, ethylene glycol, propylene glycol monomethyl ether (PGME); ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 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 mono Ethers such as tilether acetate (PGMEA), ethyl ether, tetrahydrofuran, dioxane; amides such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA); ethanolamine, diethylamine, triethylamine, etc. Amines 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 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 metal alkoxides and α, β-unsaturated carboxylic acids have high solubility in alcohols and can stably maintain a solution state without being decomposed in alcohols. .

  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 performance as an electronic device is not significantly impaired.

  In the composition, the total concentration of the solvent is not particularly limited, but is usually 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, and usually less than 100% by mass. It is more preferable that it is 50 mass% or less, and it is especially preferable that it is 20 mass% or less.

<1.4. Metal atom selected from Group 1 element of Periodic Table, Group 2 element of Periodic Table, and Group 5 element of Periodic Table>
In addition to the metal alkoxide, α, β-unsaturated carboxylic acid, and solvent, the composition according to the present invention is further selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table It may contain one or more metal atoms.

  Metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table and Group 5 elements of the periodic table are not particularly limited, but are lithium atoms, sodium atoms, potassium atoms, cesium atoms, magnesium atoms, calcium An atom, a strontium atom, a barium atom, a vanadium atom, a niobium atom, or a tantalum atom is mentioned.

  When these metal atoms are contained in the composition, the composition can be uniformly applied to a desired substrate without any defects. Although the detailed mechanism is unknown, it is considered that the presence of the metal atom inhibits aggregation of metal alkoxide. Further, since the metal atoms remain in the obtained metal oxide-containing layer, a doping effect can be expected.

  The doping effect refers to an effect of adjusting the carrier density of electric charges (electrons and holes) of a semiconductor or controlling physical properties such as energy levels by adding a small amount of dopant. In a photoelectric conversion element using a doped metal oxide-containing layer, the charge transport capability is improved by a change in carrier density, which leads to an improvement in short circuit current and FF, and a change in energy level leads to an improvement in open circuit voltage. As a result, the photoelectric conversion efficiency tends to be improved.

  The change in charge transport capability can be represented by, for example, a change in resistivity. The resistivity can be measured with a Lorester GP manufactured by Mitsubishi Chemical Analytech.

  The change in energy level can be expressed by a change in Fermi level, for example. The Fermi level can be measured by a KP technology measuring device KP020 system.

  In addition, one or more metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table may be contained as simple elements in the composition, or metal It may be contained as a compound. There are no particular restrictions on the type of metal compound, and metal oxides, metal hydroxides, metal peroxides, carbonates, acetates and other carboxylates, phosphates, nitrates, sulfates, metal alkoxides and acetyls An acetonate complex is mentioned.

  The compound containing a metal atom selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table contained in the composition according to the present invention is one kind of compound as described above. It may be a mixture of two or more. For example, the sodium compound can be a mixture of sodium oxide, sodium hydroxide, sodium carbonate, sodium acetate, and the like. Such a mixture of sodium compounds can be obtained, for example, by performing a heat treatment using sodium acetate as a raw material.

  The composition according to the present invention may contain two or more metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table. These metal atoms need not have the same valence.

  The metal atom selected from Group 1 element of Periodic Table, Group 2 element of Periodic Table, and Group 5 element of Periodic Table is a transition metal element of Period 4 of Periodic Table constituting Periodic Table, Group 12 of Periodic Table. It may be the same metal element as the metal atom selected from the elements, Group 13 elements of the periodic table, and Group 14 elements of the periodic table. For example, the vanadium atom is a group 5 element in the periodic table and a transition metal element in the fourth period of the periodic table. In this case, even if the same metal element is used, it is considered that the above-described effects can be obtained if the valence is different in the composition.

  Although the total concentration of metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table contained in the composition is not particularly limited, the total mass of the composition Is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, particularly preferably 0.001% by mass or more, and on the other hand, 50% by mass or less. It is preferably 25% by mass or less, more preferably 10% by mass or less. If the total concentration of metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table contained in the composition is within the above range, the metal oxide-containing layer Is preferable in that it can be easily applied uniformly and a uniform metal oxide-containing layer can be obtained.

  Further, the composition ratio of metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table with respect to the number of atoms of the metal atoms constituting the metal alkoxide contained in the composition is 0.1 atomic% or more, preferably 0.3 atomic% or more, more preferably 0.5 atomic% or more, and particularly preferably 1.0 atomic% or more. On the other hand, it is preferably 50 atom% or less, more preferably 30 atom% or less, more preferably 20% atom or less, and particularly preferably 10 atom% or less. A composition ratio in the above range is preferable in that the electrical characteristics of the obtained electronic device can be improved.

  As a method for obtaining the composition ratio of metal atoms in the composition, there is ICP (inductively coupled plasma) measurement. In the present invention, when the metal oxide-containing layer is formed, a heat treatment step is required as described later, and the composition ratio is different between the composition and the formed metal oxide-containing layer. It does not necessarily match.

  The composition according to the present invention may contain additives other than those described above as long as the effects according to the present invention are not impaired. For example, a surfactant may be included for the purpose of suppressing the formation of dents in the resulting metal oxide-containing layer due to adhesion of fine bubbles or foreign matter, or preventing uneven coating in the drying process. Good.

  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 composition according to the present invention has extremely high stability, as can be seen from the results of Examples described later. Therefore, since the composition according to the present invention can be mass-produced and stored for a long time, the production cost can be reduced. The reason why the stability of the composition according to the present invention is high is that the progress of the hydrolysis reaction of the metal alkoxide in the composition is suppressed by the coordination of the α, β-unsaturated carboxylic acid to the metal alkoxide. It is thought that.

  The stability of the composition can be evaluated by the formation of a precipitate, a change in viscosity, and the like. Formation of the precipitate in the composition can be judged visually or with a dynamic light scattering particle size measuring device. In addition, the viscosity of the composition according to the present invention can be determined by a rotational viscometer method ("Physical Chemistry Experiments" (described in Ginya Adachi, Yasutaka Ishii, Gohiro Yoshida, edited by Kagaku Dojin (1993)). Specifically, it can be measured using a RE85 viscometer (manufactured by Toki Sangyo Co., Ltd.).

  The composition is preferably stable for 2 weeks or more, and more preferably stable for 1 month or more.

<2. Step of forming metal oxide-containing layer>
The composition according to the present invention is applied to a desired substrate for forming a metal oxide-containing layer (hereinafter sometimes referred to as a composition application step), and heat treatment after application (hereinafter sometimes referred to as a heat treatment step). The metal oxide-containing layer according to the present invention can be formed.

<2.1. Composition application step>
Arbitrary methods can be used as a method for applying the 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 one type of coating method may be used, or two or more types of methods may be used in combination.

<2.2. Heat treatment process>
A metal oxide content layer can be formed by performing a heat treatment process after the composition application process. Specifically, the metal alkoxide contained in the composition is considered to generate a metal oxide by causing a hydrolysis reaction.

  In the method for forming a metal oxide-containing layer according to the present invention, the α, β-unsaturated carboxylic acid in the composition accelerates the hydrolysis reaction of a metal alkoxide as an acid catalyst, thereby The hydrolysis reaction can proceed at a lower temperature, lower humidity, and shorter time than the decomposition reaction (supervised by Masayuki Nogami, “Latest Application and Prospect of Sol-Gel Method” (CM Publishing, 2014)).

  In addition, a part of the α, β-unsaturated carboxylic acid is volatilized by the heat treatment process, but an α, β-unsaturated carboxylic acid polymer is formed from a part of the α, β-unsaturated carboxylic acid by the polymerization reaction. Is done. When the produced α, β-unsaturated carboxylic acid polymer remains in an appropriate amount in the metal oxide-containing layer, it functions as a binder and contributes to an improvement in flexibility of the metal oxide-containing layer.

  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 production process using a flexible substrate such as a roll-to-roll method.

  On the other hand, although there is no particular limitation, the heat treatment temperature is usually 30 ° C. or higher, preferably 50 ° C. or higher, more preferably 80 ° C. or higher, and particularly preferably 100 ° C. or higher. The reason why 100 ° C. or higher is particularly preferable is that the temperature at which water changes to water vapor having a high degree of freedom is 100 ° C. or higher. Since water vapor plays a role as a reactant in the hydrolysis reaction, the presence of water vapor is considered to promote the change from metal alkoxide to metal oxide, and the heat treatment time can be shortened.

  Performing heat treatment at a lower temperature is advantageous in that it is possible to use a flexible base material using a resin base material such as polyethylene terephthalate or a composite material provided with insulating properties on a metal foil such as copper. It is. In particular, in flexible electronic devices, construction of a process capable of producing a metal oxide thin film having a high density and high properties 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 forming a metal oxide-containing layer according to the present invention, a metal oxide-containing layer having high characteristics can be produced at a low temperature.

  The heat treatment time is not particularly limited as long as the metal oxide formation 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. If the heat treatment time is in the above range, the production reaction can proceed sufficiently, and the production reaction proceeds smoothly even in practical production processes such as the roll-to-roll method, thereby improving productivity. This is preferable.

  Note that if the heat treatment temperature is lower than 300 ° C. and the temperature is high, the formation reaction from the metal alkoxide to the metal oxide tends to proceed. Can be formed. On the other hand, even if the heat treatment temperature is low, the metal oxide-containing layer can be formed by increasing the heating time. Therefore, the heat treatment time and temperature may be appropriately selected depending on the substrate used.

  In the heat treatment step, it is not necessary for all of the metal alkoxides contained in the composition to be converted into metal oxides. Although there is no particular limitation, among the metal alkoxides contained in the composition, the metal alkoxide that changes to a metal oxide is preferably 80 mol% or more, more preferably 90 mol% or more, 95 mol% or more is particularly preferable. In addition, the ratio of the metal oxide in a metal oxide content layer can be quantified with a spectrophotometer or X-ray photoelectron spectroscopy (XPS or ESCA).

  Moreover, since a metal oxide is produced | generated by the hydrolysis reaction of a metal alkoxide, the environment of external air, such as a water | moisture content (humidity), also affects the formation process of a metal oxide content layer. Therefore, although there is no particular limitation, the moisture concentration in the atmosphere when performing the heat treatment is preferably 0.5% or more, more preferably 1% or more as the humidity at 25 ° C. It is more preferably 3% or more, preferably 5% or more, on the other hand, preferably 80% or less, more preferably 75% or less, and 70% or less. More preferably, it is particularly preferably 65% or less. For example, if the humidity is 0.5% or more, the production of the metal oxide from the metal alkoxide tends to be performed stably at a lower temperature, and if the humidity is 80% or less, the composition can be made more uniform. It becomes possible to apply and there is a tendency that a uniform metal oxide-containing layer having better characteristics can be obtained. In this specification, the humidity at 25 ° C. refers to the relative humidity when the atmosphere is adjusted to 25 ° C.

<2.3. Metal oxide-containing layer>
The metal oxide-containing layer (hereinafter sometimes referred to as a metal oxide-containing layer according to the present invention) obtained by the above method is used as a semiconductor layer of an electronic device, for example, a buffer layer of a photoelectric conversion element as described later. Can be used.

  The metal oxide-containing layer according to the present invention contains a metal oxide and an α, β-unsaturated carboxylic acid polymer.

  Examples of the metal oxide include oxides of metal atoms selected from the transition metal elements in the fourth period of the periodic table, Group 12 elements, Group 13 elements, and Group 14 elements of the Periodic Table. Specifically, <1.1. Metal oxides mentioned in the item of metal alkoxide> are mentioned, and among them, titanium oxide, vanadium oxide, iron oxide, nickel oxide, copper oxide, zinc oxide, aluminum oxide, gallium oxide, indium oxide or tin oxide. It is preferable. Among these, titanium oxide, nickel oxide, copper oxide, zinc oxide, indium oxide or tin oxide is more preferable, and titanium oxide is particularly preferable from the viewpoint of obtaining high carrier mobility.

  The ratio of the metal oxide to the total mass of the metal oxide-containing layer is not particularly limited, but is preferably 50% by mass or more in order to improve the electrical characteristics of the metal oxide-containing layer. It is preferably 60% by mass or more, more preferably 65% by mass or more, and particularly preferably 70% by mass or more with respect to the total mass of the material-containing layer. On the other hand, when the amount of the metal oxide in the metal oxide-containing layer is 100% by mass, the flexibility of the metal oxide-containing layer is lowered and the layer itself tends to become brittle. The content of the metal oxide with respect to the total mass of the containing layer is preferably 99% by mass or less, more preferably 97% by mass or less, and further preferably 95% by mass or less.

  Examples of the α, β-unsaturated carboxylic acid polymer include an α, β-unsaturated carboxylic acid polymer produced in the above-described formation step of the metal oxide-containing layer, and specifically, the following formula (2): It is a polymer having the structural unit represented.

Wherein (2), R ^1, R ² and R ³ have the same meaning as R ^1, R ² and R ³ in the formula (1). N represents the degree of polymerization. In addition, as long as the electrical characteristics of the metal oxide-containing layer are not impaired, there is no particular limitation, but in order to improve the flexibility of the metal oxide-containing layer as a binder, n is usually 2 or more, Preferably it is 5 or more, More preferably, it is 10 or more. On the other hand, if n is too large, the electrical properties of the resulting metal oxide-containing layer tend to be lowered, and therefore it is preferably 10,000 or less, more preferably 5000 or less, and more preferably 1000 or less. It is particularly preferred.

  There is no restriction | limiting in the terminal of the superposition | polymerization part represented by Formula (2), unless an electrical property is affected, For example, a hydrogen atom or a halogen atom is mentioned.

In the equation ^{(2), (- CR 1} R 2 -CR 3 COO - -) is so that there are n, n-number of ^{(-CR 1 R 2 -CR 3 COO} - -) , respectively, It may be the same or different.

  It has been considered that a metal oxide-containing layer whose amount of metal oxide is 100% by mass tends to exhibit higher electrical characteristics than a metal oxide-containing layer containing a compound other than a metal oxide. However, according to the study by the present inventors, the metal oxide-containing layer composed of 100% by mass of the metal oxide has low flexibility, for example, contains metal oxide by a roll-to-roll method. It has been found that when the layer is formed, the metal oxide-containing layer is likely to crack or break. In addition, such a low-flexibility metal oxide-containing layer is difficult to be applied to a flexible element. Further, since such a metal oxide-containing layer is fragile, the metal oxide-containing layer It has also been found that there is a possibility that problems such as rapid deterioration of electrical characteristics may occur when such an electronic device is used in an external environment.

However, since the metal oxide-containing layer according to the present invention contains an appropriate amount of an α, β-unsaturated carboxylic acid polymer in addition to the metal oxide, it is high while maintaining high electrical characteristics. It has flexibility. Therefore, the method for forming a metal oxide-containing layer according to the present invention is a method suitable for a roll-to-roll method that requires flexibility, and is also effective when used for a flexible electronic device. Moreover, since the metal oxide containing layer which concerns on this invention has moderate film | membrane intensity | strength, when used for an electronic device, high durability can be anticipated. As described above, the reason why the metal oxide-containing layer according to the present invention has high electrical characteristics, high flexibility, and appropriate film strength is that an α, β-unsaturated carboxylic acid polymer is an ethylenic ionomer. Because it has a structure close to
1) The adhesion strength of the α, β-unsaturated carboxylic acid polymer improves the peel strength of the entire metal oxide-containing layer by causing the generated metal oxide to adhere to an adjacent layer.
2) The α, β-unsaturated carboxylic acid polymer adheres to the adjacent metal oxides one after another, thereby improving the film quality such as flexibility of the entire metal oxide-containing layer,
3) The α, β-unsaturated carboxylic acid polymer adheres to the adjacent metal oxides so that the contact area between the adjacent ones increases, and a further conductive path is formed between the adjacent metal oxides. The electrical properties of the entire inclusion layer are improved,
4) The barrier property of the α, β-unsaturated carboxylic acid polymer suppresses changes in the oxygen atom amount of the metal oxide due to the outside air environment, and stabilizes the electrical characteristics of the entire metal oxide-containing layer.
Can be considered.

  The content of the α, β-unsaturated carboxylic acid polymer in the metal oxide-containing layer according to the present invention is preferably 1% by mass or more with respect to the total mass of the metal oxide-containing layer. More preferably, it is more preferably 3% by mass or more, and particularly preferably 5% by mass or more. On the other hand, since the α, β-unsaturated carboxylic acid polymer exhibits insulating properties, if the amount of the α, β-unsaturated carboxylic acid polymer contained in the metal oxide-containing layer is too large, the metal oxide There exists a tendency for the electrical property of a content layer to fall. Therefore, the content of the α, β-unsaturated carboxylic acid polymer relative to the total mass of the metal oxide-containing layer is preferably 40% by mass or less, more preferably 30% by mass or less, and 20% by mass. More preferably, it is more preferably 10% by mass or less.

  The content of the α, β-unsaturated carboxylic acid polymer in the metal oxide-containing layer can be quantified by combining infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS or ESCA). .

  The amount of α, β-unsaturated carboxylic acid polymer contained in the metal oxide-containing layer is adjusted by appropriately selecting the amount of α, β-unsaturated carboxylic acid contained in the composition. be able to.

  The metal oxide content layer concerning the present invention may contain things other than the above-mentioned compound. For example, <1.4. The metal atom may be included in the metal atom selected from Group 1 element of the periodic table, Group 2 element of the periodic table, and Group 5 element of the periodic table. When the metal oxide-containing layer contains these metal atoms, a doping effect can be expected. That is, when the metal oxide-containing layer contains these metal atoms, the charge transport capability of the metal oxide-containing layer is improved. Therefore, it leads to improvement of the short circuit current, FF or open circuit voltage of the element, and as a result, the photoelectric conversion efficiency of the element can be improved. In addition, the metal oxide containing layer containing the said metal atom can be formed by adding the said metal atom previously in a composition and forming a metal oxide containing layer.

  These metal atoms may be contained alone or as a metal compound in the metal oxide-containing layer. Metal compounds are not particularly limited, but metal oxides, metal hydroxides, metal peroxides, carbonates, acetates and other carboxylates, phosphates, nitrates, sulfates, metal alkoxides and acetyls An acetonate complex is mentioned. The metal oxide-containing layer may contain two or more metal atoms selected from these metal elements.

  The content of the metal atom selected from Group 1 element, Group 2 element and Group 5 element of the periodic table with respect to the total mass of the metal oxide-containing layer is not particularly limited, but is 0.0001% by mass or more It is preferably 0.0005% by mass or more, more preferably 0.001% by mass or more. On the other hand, it is preferably 50% by mass or less, more preferably 25% by mass or less, and further preferably 10% by mass or less. If it is in said range, the doping effect can be anticipated. In addition, content of the said metal atom in a metal oxide content layer can be adjusted by selecting the metal atom in a composition suitably.

<2.4. Physical properties of metal oxide-containing layer>
When manufacturing an electronic device industrially, for example, when manufacturing using a roll-to-roll method, for example, when the roll is wound, the formed metal oxide-containing layer may be broken. . Therefore, the metal oxide-containing layer obtained by the method for forming a metal oxide-containing layer according to the present invention is preferable because it has high flexibility.

  The flexibility of the metal oxide-containing layer according to the present invention can be measured by a winding test of the metal oxide-containing layer generated on the flexible substrate. Specifically, the metal oxide-containing layer formed on the flexible substrate can be wound around a rod having a specific radius and visually checked for the presence or absence of cracks. The flexibility of the metal oxide-containing layer is preferably not cracked even if wound on a rod having a radius of 20000 mm or less, more preferably not cracked even if wound on a rod having a radius of 10,000 mm or less. It is particularly preferable that there is no crack even when wound.

  As for the hardness of the metal oxide-containing layer, a pencil scratch hardness test (for example, JIS K5600-5-4 (1999)), a contact-type film thickness measuring device (for example, a stylus type surface shape measuring device Dektak 150 (manufactured by ULVAC)) ) Using a cantilever needle or a winding test (for example, JIS C3216-3 (2011)).

  The durable stylus pressure of the metal oxide-containing layer according to the present invention measured by a scratch hardness test with a cantilever needle using a contact-type film thickness measuring device (stylus type surface shape measuring device Dektak 150) is usually 5.0 mg or more. , Preferably 10.0 mg or more, more preferably 15.0 mg or more. When the measured value obtained using another measuring device is converted into the durable stylus pressure of the Dektak 150 cantilever needle, the durable stylus pressure of the metal oxide-containing layer according to the present invention is usually 10000 mg or less, preferably 5000 mg. It is as follows. It is preferable that the durable stylus pressure is in the above-mentioned range because hardness suitable for an industrial production method using a roll-to-roll system and the like and desirable characteristics can be achieved at the same time.

<2.5. Electrical properties of metal oxide-containing layer>
Since the metal oxide-containing layer according to the present invention has high electrical characteristics, an electronic device having high electrical characteristics can be provided by using the metal oxide-containing layer. In addition, the electrical property of a metal oxide content layer can be represented by a resistivity, for example. The resistivity can be measured with a Lorester GP manufactured by Mitsubishi Chemical Analytech.

The resistivity of the metal oxide-containing layer according to the present invention is usually 10 ¹² [Ωcm] or less, preferably 10 ¹⁰ [Ωcm] or less, more preferably 10 ⁸ [Ωcm] or less, and further preferably 10 ⁷ [Ωcm]. Hereinafter, it is particularly preferably 10 ⁶ [Ωcm] or less. On the other hand, there is no lower limit because the metal oxide-containing layer is preferably a conductor.

<3. 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 property. 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, field effect transistor elements (FETs), electroluminescent elements (LEDs), photoelectric conversion elements, and solar cells will be described in detail as preferred examples of the electronic device according to the present invention.

<4. 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.

For example, platinum, gold, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, sodium, or other metals; indium oxide (In ₂ O ₃ ), conductive oxides such as tin oxide (SnO ₂ ) and indium tin oxide (ITO); conductive polymers such as polyaniline, polypyrrole, polythiophene and polyacetylene; Bronsted acids such as hydrochloric acid, sulfuric acid and sulfonic acid; Hexafluorophosphate ions (PF ₆ ⁻ ), Lewis acids such as arsenic pentafluoride (AsF ₅ ) and iron chloride (FeCl ₃ ), dopants such as halogen atoms such as iodine, metal atoms such as sodium and potassium, etc. Added to such conductive polymers; carbon black, metal particles, etc. dispersed Material is used having conductivity such as sexual composites.

  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.

  Examples of the material used for the insulator layer 52 include polymers such as polymethyl methacrylate, polystyrene, polyvinyl phenol, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, epoxy resin, and phenol resin. These copolymers; 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 oxides, nitrides thereof, and A polymer in which particles such as a ferroelectric oxide are dispersed may be mentioned.

  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.

  The FET element is usually produced on the 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. Applicable.

  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.

  In the FET element according to the present invention, the semiconductor layer 51 is formed by forming a semiconductor film on the substrate directly or via another layer, and it is preferable to use the metal oxide-containing layer according to the present invention. As described above, the metal oxide-containing layer may contain a metal oxide and a semiconductor compound other than the α, β-unsaturated carboxylic acid polymer.

  The semiconductor layer 51 may have a stacked structure of a metal oxide-containing layer 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.

<5. 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.

<5.1. 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 in the present invention as described above, it becomes possible to produce an electroluminescent element 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.

<5.2. 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 thickness of the anode 32 varies depending on the required transparency. When the anode 32 requires transparency, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode 2 is usually 5 to 1000 nm, preferably 10 to 10%. It is 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).

<5.3. 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.

<5.4. 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 deposition 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. A hole transport layer 34 is formed on the hole injection layer 33 on the substrate, which is evaporated and 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.

<5.5. 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.

<5.6. 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 and the like are used, and the content of the alkali metal in the electron transport layer is preferably 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.

<5.7. 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.

<5.8. 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.

<6. 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. 1, one 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. Moreover, the photoelectric conversion element may optionally have another layer other than the above. Hereinafter, each component of the photoelectric conversion element will be described.

<6.1. 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 method, 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, 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 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.

<6.2. 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 anode materials include conductive metal oxides such as nickel oxide, tin oxide, indium oxide, indium tin oxide (ITO), indium-zirconium 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 (electric characteristics, wetting characteristics, etc.) may be improved by performing 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.

<6.3. 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.

<6.3.1. 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.

<6.3.2. 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 a conductive polymer 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.

<6.4. Active layer (103)>
The active layer 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, 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 for the active layer, 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. .

  As the layer structure of the active layer, a thin film stacked 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, and p-type Examples include a 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. 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 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 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.

<6.4.1. p-type semiconductor compound>
The p-type semiconductor compound included in the active layer 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.

<6.4.1.1. 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 figure is CH or N.

R ^{11 to} R ¹⁴ in the figure 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. One of the above compounds may be used, or a mixture of a plurality 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.

<6.4.1.2. 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. The conjugated polymers, ^{e.g., Handbook of Conducting Polymers, 3 rd} 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.

<6.4.1.3. 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.

<6.4.1.4. 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 is 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.

<6.4.2. 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. One of the above compounds may be used, or a mixture of a plurality 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.

<6.4.2.1. 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 usually 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 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.

<6.4.2.2. 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.

<6.4.2.3. 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.

<6.4.2.4. 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.

<6.4.2.5. 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.

<6.5. Annealing process>
After laminating the anode or the cathode, the photoelectric conversion element is usually heated in a temperature range of 50 ° C. or higher, preferably 80 ° C. or higher, usually 300 ° C. or lower, preferably 280 ° C. or lower, more preferably 250 ° C. or lower. It 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, 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.

<6.6. 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.

<7. Solar Cell According to the Present Invention>
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, a sealing material 7, a getter material film 8, a gas barrier film 9, and a 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. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 10 described later, at least one of the getter material film 8 and the gas barrier film 9 is used depending on the application. It does not have to be.

<7.1. Weatherproof Protective Film (1)>
The weather-resistant protective film 1 is a film that protects the solar cell element 6 from weather changes. By covering the solar cell element 6 with the weather-resistant protective film 1, the solar cell element 6 and the like are protected from weather changes and the power generation capacity is kept high. Since the weather-resistant protective film 1 is located on the outermost layer of the thin-film solar cell 14, the weather-resistant protective film 1 of the thin-film solar cell 14 such as weather resistance, heat resistance, transparency, water repellency, contamination resistance, and mechanical strength is included. It is preferable to have properties suitable for a surface coating material and to maintain it for a long period of time in outdoor exposure.

  Moreover, it is preferable that the weather-resistant protective film 1 transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is preferably 80% or more, and the upper limit is not limited. Furthermore, since the thin-film solar cell 14 is often heated by receiving light, it is preferable that the weather-resistant protective film 1 also has heat resistance. From this viewpoint, the melting point of the constituent material of the weather-resistant protective film 1 is usually 100 ° C. or higher and 350 ° C. or lower.

  The material which comprises the weather-resistant protective film 1 is arbitrary as long as it can protect the solar cell element 6 from a weather change. Examples of the material include polyethylene resin, polypropylene resin, cyclic polyolefin resin, AS (acrylonitrile-styrene) resin, ABS (acrylonitrile-butadiene-styrene) resin, polyvinyl chloride resin, fluorine resin, polyethylene terephthalate, polyethylene Examples thereof include polyester resins such as naphthalate, phenol resins, polyacrylic resins, polyamide resins such as various nylons, polyimide resins, polyamide-imide resins, polyurethane resins, cellulose resins, silicon resins, and polycarbonate resins.

  In addition, the weather-resistant protective film 1 may be formed with 1 type of material, and may be formed with 2 or more types of materials. Moreover, although the weather-resistant protective film 1 may be formed with the single layer film, the laminated | multilayer film provided with the film of two or more layers may be sufficient as it.

  The thickness of the weather-resistant protective film 1 is not particularly defined, but is usually 10 μm or more and 200 μm or less.

  Further, the weatherproof protective film 1 may be subjected to a surface treatment such as at least one of a corona treatment and a plasma treatment in order to improve adhesion with other films.

  The weatherproof protective film 1 is preferably provided on the outer side as much as possible in the thin-film solar cell 14. This is because more of the constituent members of the thin-film solar cell 14 can be protected.

<7.2. UV cut film (2)>
The ultraviolet cut film 2 is a film that prevents the transmission of ultraviolet rays. The ultraviolet cut film 2 is provided in the light receiving portion of the thin-film solar cell 14, and the ultraviolet cut film 2 covers the light receiving surface 6a of the solar cell element 6, so that the solar cell element 6 and, if necessary, the gas barrier films 3 and 9 are exposed to ultraviolet rays. The power generation capacity can be maintained at a high level.

  The degree of the ability to suppress the transmission of ultraviolet rays required for the ultraviolet cut film 2 is preferably such that the transmittance of ultraviolet rays (for example, wavelength of 300 nm) is 50% or less, and there is no limit on the lower limit. Moreover, it is preferable that the ultraviolet cut film 2 transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is preferably 80% or more, and the upper limit is not limited.

  Furthermore, since the thin film solar cell 14 is often heated by receiving light, the ultraviolet cut film 2 preferably has heat resistance. From this viewpoint, the melting point of the constituent material of the ultraviolet cut film 2 is usually 100 ° C. or higher and 350 ° C. or lower.

  Moreover, it is preferable that the ultraviolet cut film 2 is high in flexibility, has good adhesion to an adjacent film, and can cut water vapor and oxygen.

  The material which comprises the ultraviolet cut film 2 is arbitrary if the intensity | strength of an ultraviolet-ray can be weakened. Examples of the material include films formed by blending an ultraviolet absorber with an epoxy, acrylic, urethane, or ester resin. Further, a film in which a layer of an ultraviolet absorbent dispersed or dissolved in a resin (hereinafter referred to as “ultraviolet absorbing layer” as appropriate) is formed on a base film may be used.

  Examples of the ultraviolet absorber that can be used include salicylic acid-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ones. In addition, a ultraviolet absorber may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio. As described above, a film in which an ultraviolet absorbing layer is formed on a base film can also be used as the ultraviolet absorbing film. Such a film can be produced, for example, by applying a coating solution containing an ultraviolet absorber on a substrate film and drying it.

  Although the material of a base film is not specifically limited, For example, polyester is mentioned at the point from which the balance of heat resistance and a softness | flexibility is obtained.

  Examples of specific products of the ultraviolet cut film 2 include cut ace (MKV Plastic Co., Ltd.). In addition, the ultraviolet cut film 2 may be formed with 1 type of material, and may be formed with 2 or more types of materials.

  Further, the ultraviolet cut film 2 may be formed of a single layer film, but may be a laminated film including two or more layers. The thickness of the ultraviolet cut film 2 is not particularly limited, but is usually 5 μm or more and 200 μm or less.

  Although the ultraviolet cut film 2 should just be provided in the position which covers at least one part of the light-receiving surface 6a of the solar cell element 6, Preferably it is provided in the position which covers all the light-receiving surfaces 6a of the solar cell element 6. FIG. However, the ultraviolet cut film 2 may be provided at a position other than the position covering the light receiving surface 6 a of the solar cell element 6.

<7.3. Gas barrier film (3)>
The gas barrier film 3 is a film that prevents permeation of water and oxygen. By covering the solar cell element 6 with the gas barrier film 3, the solar cell element 6 can be protected from water and oxygen, and the power generation capacity can be kept high.

Although the degree of moisture-proof capability required for the gas barrier film 3 varies depending on the type of the solar cell element 6 and the like, the water vapor transmission rate per unit area (1 m ² ) per day is usually 1 × 10 ^−1. It is preferable that it is below g / m < ² > / day, and there is no restriction | limiting in a minimum.

The degree of oxygen permeability required for the gas barrier film 3 varies depending on the type of the solar cell element 6 and the like, but the oxygen permeability per unit area (1 m ² ) is usually 1 × 10 ^−. It is preferably ¹ cc / m ² / day / atm or less, and the lower limit is not limited.

  Moreover, it is preferable that the gas barrier film 3 transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, and there is no upper limit.

  Furthermore, since the thin film solar cell 14 is often heated by receiving light, it is preferable that the gas barrier film 3 also has heat resistance. From this viewpoint, the melting point of the constituent material of the gas barrier film 3 is usually 100 ° C. or higher and 350 ° C. or lower.

  The specific configuration of the gas barrier film 3 is arbitrary as long as the solar cell element 6 can be protected from water. However, since the manufacturing cost increases as the amount of water vapor or oxygen that can permeate the gas barrier film 3 increases, it is preferable to use an appropriate film considering these points comprehensively.

Particularly suitable gas barrier film 3 includes, for example, a film obtained by vacuum-depositing silicon oxide (SiO _x ) on a base film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).

  In addition, the gas barrier film 3 may be formed with 1 type of material, and may be formed with 2 or more types of materials. The gas barrier film 3 may be formed of a single layer film, but may be a laminated film including two or more layers.

  The thickness of the gas barrier film 3 is not particularly defined, but is usually 5 μm or more and 200 μm or less.

  As long as the gas barrier film 3 can cover the solar cell element 6 and protect it from moisture and oxygen, the formation position is not limited, but the front surface of the solar cell element 6 (surface on the light receiving surface side, lower surface in FIG. 4) and It is preferable to cover the back surface (the surface opposite to the light receiving surface; the upper surface in FIG. 4). This is because the front and back surfaces of the thin film solar cell 14 are often formed in a larger area than the other surfaces. In this embodiment, the gas barrier film 3 covers the front surface of the solar cell element 6, and a gas barrier film 9 described later covers the back surface of the solar cell element 6. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as a back sheet 10 described later, at least one of the getter material film 8 and the gas barrier film 9 is not used depending on the application. May be.

<7.4. Getter Material Film (4)>
The getter material film 4 is a film that absorbs at least one of moisture and oxygen. By covering the solar cell element 6 with the getter material film 4, the solar cell element 6 and the like are protected from at least one of moisture and oxygen, and the power generation capacity is kept high. Here, unlike the gas barrier film 3 as described above, the getter material film 4 does not prevent moisture permeation but absorbs moisture. By using a film that absorbs moisture, the getter material film 4 captures moisture that slightly enters the space formed by the gas barrier films 3 and 9 when the solar cell element 6 is covered with the gas barrier film 3 or the like. The influence of moisture on the solar cell element 6 can be eliminated.

The degree of moisture absorption capacity of the getter material film 4 is usually 0.1 mg / cm ² or more, and although there is no upper limit, it is usually 10 mg / cm ² or less. Further, when the solar cell element 6 is covered with the gas barrier films 3 and 9 or the like by the getter material film 4 absorbing oxygen, the oxygen that slightly enters the space formed by the gas barrier films 3 and 9 is obtained as the getter material. The film 4 can capture and eliminate the influence of oxygen on the solar cell element 6.

  Furthermore, it is preferable that the getter material film 4 transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, and there is no upper limit.

  Furthermore, since the thin film solar cell 14 is often heated by receiving light, the getter material film 4 preferably has heat resistance. From this viewpoint, the melting point of the constituent material of the getter material film 4 is usually 100 ° C. or higher and 350 ° C. or lower.

  The material constituting the getter material film 4 is arbitrary as long as it can absorb at least one of moisture and oxygen. Examples of the material include alkali metal, alkaline earth metal or alkaline earth metal oxides; alkali metal or alkaline earth metal hydroxides; silica gel, zeolitic compounds, magnesium sulfate. And sulfates such as sodium sulfate or nickel sulfate; and organometallic compounds such as aluminum metal complexes or aluminum oxide octylates. Specifically, examples of the alkaline earth metal include calcium, strontium, and barium. Examples of the alkaline earth metal oxide include calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO). In addition, Zr-Al-BaO and aluminum metal complexes are also included. If a specific brand name is given, for example, OleDry (manufactured by Futaba Electronics Co., Ltd.) may be mentioned.

  Examples of the substance that absorbs oxygen include activated carbon, silica gel, activated alumina, molecular sieve, magnesium oxide, and iron oxide. In addition, iron, manganese, zinc, and inorganic salts such as sulfates, chlorides, and nitrates of these metals are also included.

  In addition, the getter material film 4 may be formed of one type of material or may be formed of two or more types of materials. The getter material film 4 may be formed of a single layer film, but may be a laminated film including two or more layers.

  The thickness of the getter material film 4 is not particularly specified, but is usually 5 μm or more and 200 μm or less.

  If the getter material film 4 is in the space formed by the gas barrier films 3 and 9, the formation position is not limited, but the front surface of the solar cell element 6 (light receiving surface side surface; lower surface in FIG. 4). And it is preferable to cover the back surface (surface opposite to the light receiving surface; upper surface in FIG. 4). This is because, in the thin film solar cell 14, the front and back surfaces are often formed in a larger area than the other surfaces, and therefore moisture and oxygen tend to enter through these surfaces. From this viewpoint, the getter material film 4 is preferably provided between the gas barrier film 3 and the solar cell element 6. In this embodiment, the getter material film 4 covers the front surface of the solar cell element 6, a getter material film 8 described later covers the back surface of the solar cell element 6, and the getter material films 4 and 8 are respectively the solar cell element 6 and the gas barrier film 3. , 9 are located between them. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as a back sheet 10 described later, at least one of the getter material film 8 and the gas barrier film 9 is not used depending on the application. May be.

<7.5. Encapsulant (5)>
The sealing material 5 is a film that reinforces the solar cell element 6. Since the solar cell element 6 is thin, the strength is usually weak, and thus the strength of the thin film solar cell tends to be weak. However, the strength can be maintained high by the sealing material 5.

  Moreover, it is preferable that the sealing material 5 has high strength from the viewpoint of maintaining the strength of the thin-film solar cell 14. The specific strength is related to the strength of the weatherproof protective film 1 other than the sealing material 5 and the strength of the back sheet 10 and is generally difficult to define, but the thin film solar cell 14 as a whole has good bending workability. However, it is desirable to have a strength that does not cause peeling of the bent portion.

  Moreover, it is preferable that the sealing material 5 permeate | transmits visible light from a viewpoint which does not prevent the light absorption of the solar cell element 6. FIG. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, and there is no upper limit.

  The thickness of the sealing material 5 is not particularly specified, but is usually 2 μm or more and 700 μm or less.

  The T-type peel adhesion strength of the sealing material 5 to the substrate is usually 1 N / inch or more and usually 2000 N / inch or less. It is preferable that the T-type peel adhesive strength is 1 N / inch or more in terms of ensuring the long-term durability of the module. It is preferable that the T-type peel adhesive strength is 2000 N / inch or less in that the base material, the barrier film, and the adhesive can be separated and discarded when the solar cell is discarded. The T-type peel adhesion strength is measured by a method according to JIS K6854-3 (1999).

  The constituent material of the sealing material 5 is not particularly limited as long as it has the above characteristics, but sealing of organic / inorganic solar cells, sealing of organic / inorganic LED elements, sealing of electronic circuit boards, etc. In general, a sealing material generally used can be used.

  Specifically, a thermosetting resin composition or a thermoplastic resin composition and an active energy ray curable resin composition can be mentioned. The active energy ray-curable resin composition is, for example, a resin that is cured by ultraviolet rays, visible light, electron beams, or the like. More specifically, an ethylene-vinyl acetate copolymer (EVA) resin composition, a hydrocarbon resin composition, an epoxy resin composition, a polyester resin composition, an acrylic resin composition, and a urethane resin composition. Or a silicon-based resin composition, etc., depending on the main chain, branched chain, terminal chemical modification of each polymer, adjustment of molecular weight, additives, etc., thermosetting, thermoplastic and active energy ray curable, etc. The characteristics are expressed.

  Moreover, since the thin film solar cell 14 is often heated by receiving light, it is preferable that the sealing material 5 also has heat resistance. From this viewpoint, the melting point of the constituent material of the sealing material 5 is usually 100 ° C. or higher and 350 ° C. or lower.

The density of the constituent material for sealing material in the sealing material 5 is preferably 0.80 g / cm ³ or more, and there is no upper limit. The measurement and evaluation of density can be performed by a method based on JIS K7112 (1999).

  Although there is no restriction | limiting in the position which provides the sealing material 5, Usually, it provides so that the solar cell element 6 may be inserted | pinched. This is for reliably protecting the solar cell element 6. In this embodiment, the sealing material 5 and the sealing material 7 are provided on the front surface and the back surface of the solar cell element 6, respectively.

<7.6. Solar Cell Element (6)>
The solar cell element 6 is the same as the photoelectric conversion element 107 described above. That is, the thin-film solar cell 14 can be manufactured using the photoelectric conversion element 107.

  Although only one solar cell element 6 may be provided for each thin film solar cell 14, usually two or more solar cell elements 6 are provided. The specific number of solar cell elements 6 may be set arbitrarily. When a plurality of solar cell elements 6 are provided, the solar cell elements 6 are often arranged in an array.

  When a plurality of solar cell elements 6 are provided, the solar cell elements 6 are usually electrically connected to each other, and electricity generated from the connected group of solar cell elements 6 is taken out from a terminal (not shown). At this time, the solar cell elements are usually connected in series in order to increase the voltage.

  Thus, when connecting the solar cell elements 6, it is preferable that the distance between the solar cell elements 6 is small, and the clearance between the solar cell element 6 and the solar cell element 6 is preferably narrow. This is because the light receiving area of the solar cell element 6 is widened to increase the amount of received light, and the amount of power generated by the thin film solar cell 14 is increased.

<7.7. Sealant (7)>
The sealing material 7 is a film similar to the sealing material 5 described above, and the same material as the sealing material 7 can be used in the same manner except that the arrangement position is different. Moreover, since the constituent member on the back side of the solar cell element 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

<7.8. Getter Material Film (8)>
The getter material film 8 is the same film as the getter material film 4 described above, and the same material as the getter material film 4 can be used as necessary, except for the arrangement position. Moreover, since the constituent member on the back side of the solar cell element 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

<7.9. Gas barrier film (9)>
The gas barrier film 9 is the same film as the gas barrier film 3 described above, and the same material as the gas barrier film 9 can be used as necessary except that the arrangement position is different. Moreover, since the constituent member on the back side of the solar cell element 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

<7.10. Back sheet (10)>
The back sheet 10 is the same film as the weather-resistant protective film 1 described above, and the same material as the weather-resistant protective film 1 can be used in the same manner except that the arrangement position is different. In addition, if the back sheet 10 is difficult to permeate water and oxygen, the back sheet 10 can also function as a gas barrier layer. Moreover, since the constituent member on the back side of the solar cell element 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

<7.11. Dimensions>
The thin film solar cell 14 of the present embodiment is usually a thin film member. Thus, by forming the thin film solar cell 14 as a film-like member, the thin film solar cell 14 can be easily installed in a building material, an automobile, an interior, or the like. The thin-film solar cell 14 is light and difficult to break. Therefore, a highly safe solar cell can be obtained, and can be applied to curved surfaces, so that it can be used for more applications. Since it is thin and light, it is preferable in terms of distribution such as transportation and storage. Furthermore, since it is in the form of a film, it can be manufactured in a roll-to-roll manner, and the cost can be greatly reduced.

  Although there is no restriction | limiting in the specific dimension of the thin film solar cell 14, The thickness is usually 300 micrometers or more and 3000 micrometers or less.

<7.12. Manufacturing method>
Although there is no restriction | limiting in the manufacturing method of the thin film solar cell 14 of this embodiment, For example, as a solar cell manufacturing method of the form of FIG. 4, after producing the laminated body shown by FIG. Is mentioned. Since the solar cell element of this embodiment is excellent in heat resistance, it is preferable in that deterioration due to the laminate sealing step is reduced.

  The laminate production shown in FIG. 4 can be performed using a known technique. The method of the laminating and sealing step is not particularly limited as long as the effects of the present invention are not impaired. For example, the wet laminating method, the dry laminating method, the hot melt laminating method, the extrusion laminating method, the coextrusion laminating method, and the extrusion coating method. And laminating method using a photo-curing adhesive and thermal laminating method. Of these, the laminating method using a photo-curing adhesive having a proven record in OLED device sealing, the hot melt laminating method or the thermal laminating method having a proven record in solar cells are preferable, and the hot melt laminating method or the thermal laminating method is more preferably a sheet-like sealing. It is more preferable at the point which can use a stopping material.

  The heating temperature in the laminate sealing step is usually 130 ° C or higher, preferably 140 ° C or higher, and is usually 180 ° C or lower, preferably 170 ° C or lower. The heating time in the laminate sealing step is usually 10 minutes or longer, preferably 20 minutes or longer, and is usually 100 minutes or shorter, preferably 90 minutes or shorter. The pressure in the laminate sealing step is usually 0.001 MPa or more, preferably 0.01 MPa or more, and usually 0.2 MPa or less, preferably 0.1 MPa or less. By setting the pressure within this range, sealing can be performed reliably, and the reduction of the film thickness due to the protrusion of the sealing materials 5 and 7 from the end portion and overpressurization can be suppressed, thereby ensuring dimensional stability. In addition, what connected two or more solar cell elements 6 in series or in parallel can be manufactured similarly to the above.

<7.13. Application>
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. Examples of the field to which the thin-film solar cell according to the present invention is applied include building material solar cells, automobile solar cells, interior solar cells, railway solar cells, marine solar cells, airplane solar cells, and spacecrafts. It is a solar cell, a solar cell for home appliances, a solar cell for mobile phones, or a solar cell for toys.

  The solar cell according to the present invention, in particular, a thin film solar cell may be used as it is, or one or more solar cells may be installed on a base material and used as a solar cell module. For example, as schematically shown in FIG. 5, a solar cell module 13 provided with a thin film solar cell 14 on the substrate 12 may be prepared and used at the place of use. That is, the solar cell module 13 can be manufactured using the thin film solar cell 14. As a specific example, when a building material plate is used as the base material 12, a solar cell panel can be produced as the solar cell module 13 by providing the thin film solar cell 14 on the surface of the plate material.

  The substrate 12 is a support member that supports the thin film solar cell 14. Examples of the material for forming the substrate 12 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.

  In addition, 1 type may be used for the material of a base material, and 2 or more types may be used together by arbitrary combinations and a ratio. Moreover, carbon fiber may be included in these organic materials or paper materials to reinforce the mechanical strength. When the example of the base material 12 is given, Alpolic (registered trademark; manufactured by Mitsubishi Plastics) may be mentioned.

  Although there is no restriction | limiting in the shape of the base material 12, Usually, a board | plate material is used. Moreover, what is necessary is just to set the material of the base material 12, a dimension, etc. arbitrarily according to the use environment. This solar cell panel can be installed on the outer wall of a building.

  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 of the present invention is not exceeded.

<Example 1: Preparation of composition and ink stability evaluation>

[Example 1-1]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.08 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S1). When the ink (S1) was left in an uncontrolled air atmosphere (15 to 25 ° C., humidity 10 to 40%) for 2 weeks, no precipitate was visually observed. The results are shown in Table 1.

[Comparative Example 1-1]
Dissolve titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol) in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL). A colorless and transparent ink (S2) was prepared. When the ink (S2) was left in an uncontrolled air atmosphere in the same manner as in Example 1-1, a precipitate was visually confirmed after one week. The results are shown in Table 1.

  Regarding the evaluation in the column of ink stability in Table 1, each was left to stand for 2 weeks in an uncontrolled air atmosphere (15 to 25 ° C., humidity 10 to 40%), and then visually precipitated in the ink. The case where no was confirmed was marked with “◯” and the case where a precipitate was confirmed was marked with “x”.

  From the above results, it is considered that the ink stability of the composition was improved by acrylic acid.

<Example 2: Evaluation of flexibility of metal oxide-containing layer>

[Example 2-1]
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 PEN (polyethylene naphthalate) film “Teonex Q65” manufactured by Teijin DuPont Film Co., Ltd., and then in an atmospheric atmosphere using a spin coater ACT-300DII (manufactured by Active Corporation). Spin coating was performed at 1000 rpm × 30 seconds at (23 ° C., humidity 16%). Thereafter, a colorless and transparent titanium oxide-containing layer was produced by heat treatment at 150 ° C. for 10 minutes in an air atmosphere.

  About the obtained titanium oxide content layer, the film thickness was measured on the following measurement conditions using the stylus type surface shape measuring device Dektak150 (made by ULVAC). As a result, the average of five measurements was 180 nm.

(Thickness measurement conditions)
Measuring device: Dektak150
Stylus pressure: 1mg
Stylus size: Radius 12.5μm
Measurement distance: 1000 μm
Measurement time: 60 seconds Measurement mode: Standard

  As the flexibility evaluation, a winding test was performed. When the PEN film on which the titanium oxide-containing layer was laminated was wound around an iron bar having a radius of 20 mm, it was confirmed that there was no crack by visual observation. The results are shown in Table 2.

[Comparative Example 2-1]
A colorless and transparent ink (S2) was prepared in the same manner as in Comparative Example 1-1.

  Next, a titanium oxide-containing layer was produced on the PEN film in the same manner as in Example 2-1. The titanium oxide layer was a white film having a thickness of 190 nm.

  In the same manner as in Example 2-1, a winding test was performed as the flexibility evaluation. When the PEN film on which the titanium oxide-containing layer was laminated was wound around an iron bar having a radius of 20 mm, it was confirmed by visual observation that a plurality of cracks were present. The results are shown in Table 2.

[Comparative Example 2-2]
On the PEN film “Teonex Q65”, a titanium oxide (TiO ₂ ) target (manufactured by Kojundo Chemical Laboratory Co., Ltd., 99.9%) was used to produce a titanium oxide layer with a film thickness of 180 nm by RF sputtering.

  In the same manner as in Example 2-1, a winding test was performed as the flexibility evaluation. When the PEN film on which the titanium oxide layer was laminated was wound around an iron rod having a radius of 20 mm, it was confirmed by visual observation that a plurality of cracks were present. The results are shown in Table 2.

  Regarding the evaluation in the column of flexibility in Table 2, “○” indicates that a plurality of cracks are not visually confirmed after winding on a steel bar having a radius of 20 mm, and “×” indicates that a plurality of cracks are confirmed. "

  As described above, the titanium oxide-containing layer formed using the ink according to the present invention is more flexible than the titanium oxide-containing layer formed using the ink not added with acrylic acid and the titanium oxide layer formed by sputtering. It can be seen that

<Example 3: Production and evaluation of photoelectric conversion element>
[Synthesis Example 1: Synthesis of Copolymer A]

  As a monomer, 1,3-dibromo-5-octyl-4H-thieno [3,4-obtained by referring to a method described in known literature (J. Am. Chem. Soc. 2011, 133, 10062.) c] With reference to the methods described in pyrrole-4,6- (5H) -dione (Compound E1, 86 mg, 0.204 mmol) and known literature (J. Am. Chem. Soc. 2011, 133, 10062.) The resulting 4,4-bis (2-ethylhexyl) -2,6-bis (trimethyltin) -dithieno [3,2-b: 2 ′, 3′-d] silole (compound E2, 80 mg, 0.108 mmol) ) And 4,4-di-n-octyl-2,6-bis (tri) obtained by referring to the methods described in known literature (Chem. Commun., 2011, 47, 4920.). Tiltin) -dithieno [3,2-b: 2 ′, 3′-d] silole (compound E3, 80 mg, 0.108 mmol) was used to make known literature (J. Am. Chem. Soc. 2011, 133, 10062). The copolymer A was synthesized with reference to the method described in.

The weight average molecular weight Mw and PDI of the copolymer A were measured by the following methods and found to be 3.69 × 10 ⁵ and 9.4, respectively.

  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.

(GPC measurement conditions)
Column: Polymer Laboratories GPC column (PLgel MIXED-B 10 μm, inner diameter 7.5 mm, length 30 cm) 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 chloroform (200 mg)
Mobile phase: Chloroform Flow rate: 1.0 mL / min
Analysis: LC-Solution (manufactured by Shimadzu Corporation)

[Preparation of organic active layer coating solution]
Copolymer A obtained in Synthesis Example 1 and a mixture of C ₆₀ PCBM and C ₇₀ PCBM (Nanom Spectra-E123 manufactured by Frontier Carbon Co.) as an n-type semiconductor compound were mixed so that the mass ratio was 1: 3. The mixture was dissolved in a mixed solvent of orthoxylene and tetralin (volume ratio 9: 1) in a nitrogen atmosphere so that the concentration became 4% 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 1 μm polytetrafluoroethylene (PTFE) filter to obtain an organic active layer coating solution.

Ｃ₆₀ＰＣＢＭとＣ₇₀ＰＣＢＭの混合物

Mixture of C ₆₀ PCBM and C ₇₀ PCBM

[Production and Evaluation of Photoelectric Conversion Element]
[Example 3-1]
In the same manner as in Example 1-1, titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) ) And acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd., 0.08 mL, 1.125 mmol) are dissolved in ethanol (manufactured by Wako Pure Chemical Industries, Ltd., 5 mL) and isopropanol (manufactured by Kokusan Kagaku Co., Ltd., 10 mL). A transparent ink (S1) was prepared.

  Next, a glass substrate (manufactured by Geomatic Co., Ltd.) on which a transparent conductive film of indium tin oxide (ITO) with a thickness of 155 nm is deposited is subjected to ultrasonic cleaning using acetone (manufactured by Wako Pure Chemical Industries, Ltd.), isopropanol (domestic chemical) Nitrogen blow was performed after washing in the order of ultrasonic washing using a

  After 1 mL of ink (S1) is dropped on the ITO of the cleaned substrate, using a spin coater ACT-300DII (manufactured by Active), in an uncontrolled atmosphere (15-25 ° C., humidity 10-40%) And spin-coated at 5000 rpm for 30 seconds. Then, the electron extraction layer which consists of a colorless and transparent titanium oxide content layer was produced by thickness about 80 nm by heat-processing for 150 degreeC x 10 minutes in air | atmosphere.

  Subsequently, an organic active layer having a thickness of about 200 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). .

  On the organic active layer layer, molybdenum oxide (manufactured by High-Purity Chemical Laboratory) is formed as a hole extraction layer having a thickness of 5 nm by resistance heating vacuum deposition, and then silver (manufactured by Furuuchi Chemical Co., Ltd.) is resisted. A 5 mm square photoelectric conversion element was produced by forming a film as an electrode having a thickness of 80 nm by a heating type vacuum deposition method.

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 3 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 3-2]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd., 0.08 mL, 1.125 mmol) were mixed with ethanol (Wako Pure Chemical Industries, Ltd.). And 5 mL) and isopropanol (manufactured by Kokusan Kagaku Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S3).

  A 5-mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S3) to which sodium acetate was not added was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-3]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.03 mL, 0.045 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S4).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S4) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-4]
A photoelectric conversion element was produced in the same manner as in Example 3-3, except that an electron extraction layer composed of a titanium oxide-containing layer was produced by heat treatment in an atmosphere with a relative humidity of 1%. Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-5]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.15 mL, 2.25 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S5).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S5) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-6]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.31 mL, 4.5 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S6).

  A 5-mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S6) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-7]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.46 mL, 6.75 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S7).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S7) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-8]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.54 mL, 7.875 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S8).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S8) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-9]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 1.8 mg, 0.0225 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.08 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S9).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S9) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-10]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 3.7 mg, 0.045 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.08 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S10).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S10) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-11]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 18.5 mg, 0.225 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.08 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S11).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S11) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-12]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 36.9 mg, 0.45 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.08 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S12).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S12) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-13]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), potassium acetate (manufactured by Wako Pure Chemical Industries, 8.8 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.15 mL, 2.25 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S13).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S13) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-14]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), cesium carbonate (manufactured by High-Purity Chemical Laboratory, 14.7 mg, 0.045 mmol) and acrylic acid (Tokyo Chemical Industry Co., Ltd.) Product, 0.15 mL, 2.25 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S14). .

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S14) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-15]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), magnesium acetate tetrahydrate (manufactured by Wako Pure Chemical Industries, 19.3 mg, 0.09 mmol) and acrylic acid (Tokyo) A colorless and transparent ink (S15) by dissolving Kasei Kogyo Co., Ltd., 0.08 mL, 1.125 mmol) in ethanol (Wako Pure Chemical Industries, 5 mL) and isopropanol (Kokusan Chemical Co., Ltd., 10 mL). Was prepared.

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S15) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-16]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical, 1.33 mL, 4.5 mmol), calcium acetate monohydrate (manufactured by Wako Pure Chemical Industries, 19.3 mg, 0.09 mmol) and acrylic acid (Tokyo) A colorless and transparent ink (S16) is obtained by dissolving Kasei Kogyo Co., Ltd., 0.08 mL, 1.125 mmol) in ethanol (Wako Pure Chemical Industries, 5 mL) and isopropanol (Kokusan Chemical Co., Ltd., 10 mL). Was prepared.

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S16) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-17]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), strontium acetate hemihydrate (manufactured by Wako Pure Chemical Industries, 19.3 mg, 0.09 mmol) and acrylic acid (Tokyo Chemical Industry Co., Ltd., 0.08 mL, 1.125 mmol) is dissolved in ethanol (Wako Pure Chemical Industries, 5 mL) and isopropanol (Kokusan Chemical Co., Ltd., 10 mL), so that a colorless and transparent ink ( S17) was prepared.

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S17) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-18]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), barium acetate (manufactured by Wako Pure Chemical Industries, 23.0 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.08 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S18).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S18) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-19]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), niobium pentaethoxide (manufactured by Aldrich, 0.006 mL, 0.0225 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd., A colorless and transparent ink (S19) was prepared by dissolving 0.08 mL, 1.125 mmol) in ethanol (Wako Pure Chemical Industries, 5 mL) and isopropanol (Kokusan Chemical Co., 10 mL).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S19) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Example 3-20]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and crotonic acid (manufactured by Kanto Chemical Co., Ltd., A colorless and transparent ink (S20) was prepared by dissolving 96.9 mg, 1.125 mmol) in ethanol (Wako Pure Chemical Industries, 5 mL) and isopropanol (Kokusan Chemical Co., 10 mL).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S20) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-1]
In the same manner as in Comparative Example 1-1, titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), ethanol (manufactured by Wako Pure Chemical Industries, 5 mL), and isopropanol (domestic) A colorless and transparent ink (S2) was prepared by dissolving in 10 mL).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S2) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-2]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) , 0.62 mL, 9.0 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S21).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S21) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-3]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and crotonic acid (manufactured by Kanto Chemical Co., Ltd., A colorless transparent ink (S22) was prepared by dissolving 774.8 mg, 9.0 mmol) in ethanol (Wako Pure Chemical Industries, 5 mL) and isopropanol (Kokusan Chemical Co., 10 mL).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S22) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-4]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and ethanolamine (manufactured by Aldrich, 0 .07 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a light yellow transparent ink (S23).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S23) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-5]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and ethanolamine (manufactured by Aldrich, 0 .41 mL, 6.75 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a yellow transparent ink (S24).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S24) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-6]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and ethanolamine (manufactured by Aldrich, 0 .54 mL, 9.0 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a yellow transparent ink (S25).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S25) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-7]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acetic acid (manufactured by Wako Pure Chemical Industries, Ltd.) , 0.06 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S26).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S26) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-8]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and acetic acid (manufactured by Wako Pure Chemical Industries, Ltd.) , 0.39 mL, 6.75 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S27).

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S27) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

[Comparative Example 3-9]
Titanium tetra (i-propoxide) (manufactured by Kishida Chemical Co., 1.33 mL, 4.5 mmol), sodium acetate (manufactured by Wako Pure Chemical Industries, 7.4 mg, 0.09 mmol) and 2-methoxyethoxyacetic acid (Aldrich) Manufactured in water, 0.13 mL, 1.125 mmol) was dissolved in ethanol (manufactured by Wako Pure Chemical Industries, 5 mL) and isopropanol (manufactured by Kokusan Chemical Co., Ltd., 10 mL) to prepare a colorless and transparent ink (S28). .

  A 5 mm square photoelectric conversion element was produced in the same manner as in Example 3-1, except that the ink (S28) was used instead of the ink (S1). Table 3 shows measurement results of current-voltage characteristics of the photoelectric conversion elements.

  From the results of Table 3, as in Examples 3-1 to 3-20, 200 mol% or less of α, β-unsaturated with respect to titanium tetra (i-propoxide) and titanium tetra (i-propoxide). The photoelectric conversion element containing the titanium oxide containing layer produced with the metal oxide present layer forming composition according to the present invention containing a saturated carboxylic acid and a solvent was obtained by Comparative Examples 3-1 to 3-9. It turns out that conversion efficiency higher than the obtained photoelectric conversion element was measured. From this result, α, β-unsaturated carboxylic acid is an additive that can easily form a conductive path of titanium oxide because FF is particularly preferable to ethanolamine, acetic acid, and 2-methoxyethoxyacetic acid. I understand.

  In particular, all of the metal oxide-containing layers of the photoelectric conversion elements obtained in Examples 3-1, 3-3, 3-5 to 3-8, and Comparative Example 3-2 were titanium tetra (i-propoxy). ), Acrylic acid, and the total mass of each metal oxide-containing layer, the titanium tetra ( Photoelectric conversion element produced using a composition having an acrylic acid concentration of less than 200 mol% relative to a photoelectric conversion element produced using a composition having an acrylic acid concentration of 200 mol% relative to i-propoxide) It can be seen that the conversion efficiency is remarkably improved. Similarly, it can be seen that the same tendency is obtained even when the photoelectric conversion element manufactured in Example 3-20 and the photoelectric conversion element manufactured in Comparative Example 3-3 are compared. This is because an excessive amount of an α, β-unsaturated carboxylic acid-derived polymer having insulating properties is present in the metal oxide-containing layer of the photoelectric conversion element produced in Comparative Examples 3-2 and 3-3. In contrast, the photoelectric conversion elements produced in Examples 3-1 and 3-3, 3-5 to 3-8, and 3-20 are α in the metal oxide-containing layer. , Β-unsaturated carboxylic acid polymer is considered to be an appropriate amount.

  Further, from Example 3-1 and Examples 3-2 to 3-20, one or more metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table and Group 5 elements of the periodic table are added to the added metal. It turns out that the short circuit current value is improving by adding as an atom. This is thought to be due to the fact that titanium tetra (i-propoxide) could be applied neatly without agglomeration on the base material due to the added metal atoms, and that the charge transport capability was improved by the doping effect. It is done.

  Moreover, from Example 3-3 and Example 3-4, even if it heat-processes in the atmosphere of low humidity of 1% of relative humidity, the efficiency almost the same as when heat-processed in an air atmosphere is obtained. I understand.

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 Lower electrode 102 Lower buffer layer 103 Active layer 104 Upper buffer layer 105 Upper electrode 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 material 6 Solar cell element 10 Back sheet 12 Base material 13 Solar cell module 14 Thin film solar cell

Claims (12)

A composition comprising a metal alkoxide, an α, β-unsaturated carboxylic acid, and a solvent,
Content of the said (alpha), (beta)-unsaturated carboxylic acid with respect to the said metal alkoxide is 1 mol% or more and less than 200 mol%, The composition characterized by the above-mentioned. The metal atom constituting the metal alkoxide is a metal atom selected from a transition metal element of the fourth 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 according to claim 1. The composition according to claim 1 or 2, further comprising one or more metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table, and Group 5 elements of the periodic table. The total number of one or more metal atoms selected from Group 1 elements of the periodic table, Group 2 elements of the periodic table and Group 5 elements of the periodic table is 0.1 atom with respect to the metal atoms constituting the metal alkoxide. The composition according to any one of claims 1 to 3, wherein the composition is not less than 50% and not more than 50 atomic%. 5. The composition according to claim 1, wherein the α, β-unsaturated carboxylic acid has 3 or more and 12 or less carbon atoms. The composition according to claim 1, wherein the solvent is an alcohol. It is a manufacturing method of the electronic device which has a metal oxide content layer on a base material, Comprising: The composition of any one of Claims 1-6 is apply | coated on the said base material, and it heat-processes after this application | coating. The manufacturing method of the electronic device including the process of forming the said metal oxide content layer by performing. The method for manufacturing an electronic device according to claim 7, wherein the base material is a resin base material. The method for manufacturing an electronic device according to claim 7 or 8, wherein the heat treatment is performed at 30 ° C or higher and lower than 300 ° C. An electronic device having a metal oxide-containing layer comprising a metal oxide and an α, β-unsaturated carboxylic acid polymer, wherein the α, β-unsaturated carboxylic acid polymer in the metal oxide-containing layer Is 1 mass% or more and 40 mass% or less, The electronic device characterized by the above-mentioned. The electronic device of Claim 10 which is a photoelectric conversion element. A solar cell comprising the electronic device according to claim 11.

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