Method for producing ink composition

Abstract

To provide an ink composition that can be filtered more reliably without requiring trial and error and without blocking the filter in the manufacturing process, and that is less likely to cause electrical defects such as insulation and short circuits, and a method for manufacturing ink compositions that can further improve the manufacturing efficiency of the ink composition, and that of the photoelectric conversion element.SOLUTION: An ink composition for manufacturing a photoelectric conversion element comprises a p-type semiconductor material, an n-type semiconductor material, and a solvent, and the p-type semiconductor material includes a polymer compound having a z-average molecular weight of less than 5.0×105.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an ink composition for forming a functional layer of a photoelectric conversion element and a method for producing the same. [Background technology]

[0002] Photoelectric conversion elements are extremely useful devices from the standpoint of, for example, saving energy and reducing carbon dioxide emissions, and have attracted attention.

[0003] In the manufacture of a photoelectric conversion element, such as a photodetector (OPD), it is known to apply a manufacturing method in which functional layers such as an active layer, an electron transport layer, and a hole transport layer are formed by a coating method in which an ink composition for manufacturing a photoelectric conversion element is applied to a coating target (see Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Strobel 2019 Flex. Print. Electron. 4 043001 Summary of the Invention [Problem to be solved by the invention]

[0005] In a photoelectric conversion element in which a functional layer is formed by a coating method using an ink composition, for example, when forming a bulk heterojunction type active layer, the ink composition for forming the active layer usually contains a p-type semiconductor material, an n-type semiconductor material, and a solvent. If foreign matter is mixed into such an ink composition, it may cause electrical defects such as insulation and short circuit in the active layer formed using the ink composition. Therefore, when producing the ink composition, it is common to dissolve the p-type semiconductor material and the n-type semiconductor material in a solvent and then filter the mixture with a filter having a predetermined pore size.

[0006] However, in the above-mentioned conventional ink compositions, depending on the selection of the p-type semiconductor material and / or the n-type semiconductor material, the filter may become clogged during filtration, making it impossible to perform filtration in the first place, and making it impossible to produce a photoelectric conversion element. [Means for solving the problem]

[0007] The present inventors have conducted intensive research to solve the above problems, and have found that the components in the ink composition that clog the filter contain ultra-high molecular weight components of p-type semiconductor materials. However, the ultra-high molecular weight components are contained in the ink composition in extremely small amounts, and are extremely difficult to remove from the prepared ink composition. The present inventors have found that the above problems can be solved by controlling the content of the ultra-high molecular weight components of the p-type semiconductor material used as a raw material to a certain level or less and setting the z-average molecular weight of the p-type semiconductor material contained in the ink composition to a predetermined range, and have completed the present invention. Therefore, the present invention provides the following [1] to [9]. [1] An ink composition comprising a p-type semiconductor material, an n-type semiconductor material, and a solvent, wherein the p-type semiconductor material has a z-average molecular weight of 5.0×10 5 An ink composition for use in producing a photoelectric conversion element, comprising a polymer compound having a molecular weight of less than 1. [2] The p-type semiconductor material has a weight average molecular weight of 6.0 × 10 4 The ink composition for producing a photoelectric conversion element according to [1], further comprising a polymer compound having a size larger than [3] The ink composition for producing a photoelectric conversion element according to [1] or [2], wherein the p-type semiconductor material contains a polymer compound including a structural unit having a thiophene skeleton. [4] The ink composition for producing a photoelectric conversion element according to [3], wherein the p-type semiconductor material contains a polymer compound having a donor-acceptor structure. [5] The ink composition for producing a photoelectric conversion element according to any one of [1] to [4], wherein the solvent contains an aromatic hydrocarbon. [6] The ink composition for producing a photoelectric conversion element according to any one of [1] to [5], wherein the n-type semiconductor material contains a fullerene derivative. [7] The ink composition for producing a photoelectric conversion element according to any one of [1] to [5], wherein the n-type semiconductor material contains a non-fullerene compound. [8] A method for producing an ink composition for use in producing a photoelectric conversion element according to any one of [1] to [7], comprising a step of filtering the ink composition through a filter having a pore size of 0.5 μm or less. [9] A preparation step of preparing a plurality of types of polymer compounds which are p-type semiconductor materials; Among the polymer compounds prepared in the preparation step, a polymer compound having a z-average molecular weight of 5.0×10 5 a selection step of selecting a polymer compound having a molecular weight of less than 100 as a p-type semiconductor material; a step of mixing the p-type semiconductor material and the n-type semiconductor material selected in the selection step with a solvent to produce an ink composition; A method for producing an ink composition for use in producing a photoelectric conversion element, comprising: Effect of the Invention

[0008] According to the present invention, there is provided an ink composition which can be filtered more reliably without clogging a filter during the production process without the need for trial and error, and which is less likely to cause electrical defects such as insulation and short circuits, and a method for producing an ink composition which can further improve the production efficiency of the ink composition and, ultimately, the production efficiency of a photoelectric conversion element. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration example of a photoelectric conversion element. [Diagram 2] FIG. 2 is a diagram illustrating a schematic configuration example of the image detection unit. [Diagram 3] FIG. 3 is a diagram illustrating a schematic configuration example of the fingerprint detection unit. [Figure 4] FIG. 4 is a diagram illustrating a schematic configuration example of an image detection unit for an X-ray imaging device. [Diagram 5] FIG. 5 is a diagram illustrating a configuration example of a vein detection unit for use in a vein authentication device. [Figure 6] FIG. 6 is a diagram showing a schematic configuration example of an image detection unit for an indirect type TOF distance measuring device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings merely show the shape, size and arrangement of the components in a schematic manner to the extent that the invention can be understood. The present invention is not limited by the following description, and each component can be modified as appropriate without departing from the gist of the present invention. In the drawings used in the following description, similar components are indicated by the same reference numerals, and duplicated descriptions may be omitted. Furthermore, the configuration according to the embodiment of the present invention is not necessarily used in the arrangement of the illustrated example.

[0011] 1. Explanation of common terms In this specification, the term "polymer compound" refers to a polymer having a molecular weight distribution and a number average molecular weight in terms of polystyrene of 1×10 3 More than 1×10 8 The polymer compound has a total of 100 mol % of structural units.

[0012] In this specification, the term "structural unit" refers to a unit that exists in a polymer compound in one or more instances and that is derived from a monomer compound (monomer).

[0013] In this specification, a "hydrogen atom" may be a protium atom or a deuterium atom.

[0014] In this specification, examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0015] The embodiment in which "optionally has a substituent" includes both the case in which all hydrogen atoms constituting the compound or group are unsubstituted, and the case in which one or more hydrogen atoms are partially or entirely substituted with a substituent.

[0016] Examples of the substituent include a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a cycloalkynyl group, an alkyloxy group, a cycloalkyloxy group, an alkylthio group, a cycloalkylthio group, an aryl group, an aryloxy group, an arylthio group, a monovalent heterocyclic group, a substituted amino group, an acyl group, an imine residue, an amide group, an acid imide group, a substituted oxycarbonyl group, a cyano group, an alkylsulfonyl group, and a nitro group.

[0017] In this specification, the "alkyl group" may have a substituent. The "alkyl group" may be any of linear, branched, and cyclic, unless otherwise specified. The number of carbon atoms of a linear alkyl group is usually 1 to 50, preferably 1 to 30, and more preferably 1 to 20, not including the number of carbon atoms of the substituent. The number of carbon atoms of a branched or cyclic alkyl group is usually 3 to 50, preferably 3 to 30, and more preferably 4 to 20, not including the number of carbon atoms of the substituent.

[0018] Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isoamyl group, a 2-ethylbutyl group, an n-hexyl group, a cyclohexyl group, an n-heptyl group, a cyclohexylmethyl group, a cyclohexylethyl group, an n-octyl group, a 2-ethylhexyl group, a 3-n-propylheptyl group, an adamantyl group, an n-decyl group, a 3,7-dimethyloctyl group, and a 2-ethyloctyl group. unsubstituted alkyl groups such as a 2-n-hexyl-decyl group, a n-dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, or an eicosyl group; and substituted alkyl groups such as a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, a perfluorooctyl group, a 3-phenylpropyl group, a 3-(4-methylphenyl)propyl group, a 3-(3,5-di-n-hexylphenyl)propyl group, or a 6-ethyloxyhexyl group.

[0019] The "cycloalkyl group" may be a monocyclic group or a polycyclic group. The cycloalkyl group may have a substituent. The number of carbon atoms of the cycloalkyl group is usually 3 to 30, preferably 3 to 20, not including the number of carbon atoms of the substituent.

[0020] Examples of cycloalkyl groups include unsubstituted alkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and an adamantyl group, as well as groups in which the hydrogen atoms in these groups are substituted with substituents such as an alkyl group, an alkyloxy group, an aryl group, or a fluorine atom.

[0021] Specific examples of the substituted cycloalkyl group include a methylcyclohexyl group and an ethylcyclohexyl group.

[0022] The "alkenyl group" may be linear or branched. The alkenyl group may have a substituent. The number of carbon atoms in the alkenyl group is usually 2 to 30, preferably 2 to 20, not including the number of carbon atoms in the substituent.

[0023] Examples of the alkenyl group include unsubstituted alkenyl groups such as vinyl, 1-propenyl, 2-propenyl, 2-butenyl, 3-butenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 5-hexenyl, and 7-octenyl, as well as groups in which the hydrogen atoms in these groups are substituted with substituents such as alkyloxy groups, aryl groups, and fluorine atoms.

[0024] The "cycloalkenyl group" may be a monocyclic group or a polycyclic group. The cycloalkenyl group may have a substituent. The number of carbon atoms of the cycloalkenyl group is usually 3 to 30, preferably 3 to 20, not including the number of carbon atoms of the substituent.

[0025] Examples of the cycloalkenyl group include unsubstituted cycloalkenyl groups, such as a cyclohexenyl group, and groups in which a hydrogen atom in such a group is substituted with a substituent such as an alkyl group, an alkyloxy group, an aryl group, or a fluorine atom.

[0026] Examples of the substituted cycloalkenyl group include a methylcyclohexenyl group and an ethylcyclohexenyl group.

[0027] The "alkynyl group" may be linear or branched. The alkynyl group may have a substituent. The number of carbon atoms in the alkynyl group is usually 2 to 30, preferably 2 to 20, not including the number of carbon atoms in the substituent.

[0028] Examples of the alkynyl group include unsubstituted alkynyl groups such as ethynyl, 1-propynyl, 2-propynyl, 2-butynyl, 3-butynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl, and 5-hexynyl groups, as well as groups in which the hydrogen atoms in these groups are substituted with substituents such as alkyloxy groups, aryl groups, and fluorine atoms.

[0029] The "cycloalkynyl group" may be a monocyclic group or a polycyclic group. The cycloalkynyl group may have a substituent. The number of carbon atoms in the cycloalkynyl group is usually 4 to 30, preferably 4 to 20, not including the number of carbon atoms in the substituent.

[0030] Examples of the cycloalkynyl group include unsubstituted cycloalkynyl groups, such as a cyclohexynyl group, and groups in which the hydrogen atoms in these groups are substituted with substituents such as an alkyl group, an alkyloxy group, an aryl group, or a fluorine atom.

[0031] Examples of the cycloalkynyl group having a substituent include a methylcyclohexynyl group and an ethylcyclohexynyl group.

[0032] The "alkyloxy group" may be linear or branched. The alkyloxy group may have a substituent. The number of carbon atoms of the alkyloxy group is usually 1 to 30, and preferably 1 to 20, not including the number of carbon atoms of the substituent.

[0033] Examples of the alkyloxy group include unsubstituted alkyloxy groups such as a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a tert-butyloxy group, an n-pentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, a 2-ethylhexyloxy group, an n-nonyloxy group, an n-decyloxy group, a 3,7-dimethyloctyloxy group, a 3-heptyldodecyloxy group, and a lauryloxy group, as well as groups in which the hydrogen atom in these groups is substituted with a substituent such as an alkyloxy group, an aryl group, or a fluorine atom.

[0034] The cycloalkyl group in the "cycloalkyloxy group" may be a monocyclic group or a polycyclic group. The cycloalkyloxy group may have a substituent. The number of carbon atoms in the cycloalkyloxy group is usually 3 to 30, preferably 3 to 20, not including the number of carbon atoms in the substituent.

[0035] Examples of the cycloalkyloxy group include unsubstituted cycloalkyloxy groups, such as a cyclopentyloxy group, a cyclohexyloxy group, and a cycloheptyloxy group, as well as groups in which the hydrogen atom in these groups is substituted with a substituent such as a fluorine atom or an alkyl group.

[0036] The "alkylthio group" may be linear or branched. The alkylthio group may have a substituent. The number of carbon atoms of the alkylthio group is usually 1 to 30, and preferably 1 to 20, not including the number of carbon atoms of the substituent.

[0037] Examples of the alkylthio group which may have a substituent include a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, an n-butylthio group, an isobutylthio group, a tert-butylthio group, an n-pentylthio group, an n-hexylthio group, an n-heptylthio group, an n-octylthio group, a 2-ethylhexylthio group, an n-nonylthio group, an n-decylthio group, a 3,7-dimethyloctylthio group, a 3-heptyldodecylthio group, a laurylthio group, and a trifluoromethylthio group.

[0038] The cycloalkyl group of the "cycloalkylthio group" may be a monocyclic group or a polycyclic group. The cycloalkylthio group may have a substituent. The number of carbon atoms of the cycloalkylthio group is usually 3 to 30, preferably 3 to 20, not including the number of carbon atoms of the substituent.

[0039] An example of the optionally substituted cycloalkylthio group is a cyclohexylthio group.

[0040] The term "p-valent aromatic carbocyclic group" refers to the atomic group remaining after removing p hydrogen atoms directly bonded to carbon atoms constituting the ring from an aromatic hydrocarbon which may have a substituent. The p-valent aromatic carbocyclic group may further have a substituent.

[0041] The term "aryl group" refers to a monovalent aromatic carbocyclic group. The aryl group may have a substituent. The number of carbon atoms in the aryl group is usually 6 to 60, preferably 6 to 48, not including the number of carbon atoms in the substituent.

[0042] Examples of the aryl group include unsubstituted aryl groups such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, a 2-anthracenyl group, a 9-anthracenyl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenyl group, a 2-fluorenyl group, a 3-fluorenyl group, a 4-fluorenyl group, a 2-phenylphenyl group, a 3-phenylphenyl group, and a 4-phenylphenyl group, as well as groups in which a hydrogen atom in these groups is substituted with a substituent such as an alkyl group, an alkyloxy group, an aryl group, or a fluorine atom.

[0043] The "aryloxy group" may have a substituent. The number of carbon atoms of the aryloxy group is usually 6 to 60, and preferably 6 to 48, not including the number of carbon atoms of the substituent.

[0044] Examples of the aryloxy group include unsubstituted aryloxy groups, such as a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 1-anthracenyloxy group, a 9-anthracenyloxy group, and a 1-pyrenyloxy group, as well as groups in which the hydrogen atom in these groups is substituted with a substituent such as an alkyl group, an alkyloxy group, or a fluorine atom.

[0045] The "arylthio group" may have a substituent. The number of carbon atoms of the arylthio group is usually 6 to 60, and preferably 6 to 48, not including the number of carbon atoms of the substituent.

[0046] Examples of the arylthio group which may have a substituent include a phenylthio group, a C1-C12 alkyloxyphenylthio group, a C1-C12 alkylphenylthio group, a 1-naphthylthio group, a 2-naphthylthio group, and a pentafluorophenylthio group. "C1-C12" indicates that the group described immediately after has 1 to 12 carbon atoms. Furthermore, "Cm-Cn" indicates that the group described immediately after has m to n carbon atoms. The same applies below.

[0047] A "p-valent heterocyclic group" (p represents an integer of 1 or greater) refers to the atomic group remaining after removing p hydrogen atoms from among the hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting the ring of an optionally substituted heterocyclic compound. A "p-valent heterocyclic group" includes a "p-valent aromatic heterocyclic group." A "p-valent aromatic heterocyclic group" refers to the atomic group remaining after removing p hydrogen atoms from among the hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting the ring of an optionally substituted aromatic heterocyclic compound.

[0048] The aromatic heterocyclic compounds include compounds in which the heterocycle itself exhibits aromaticity, as well as compounds in which an aromatic ring is condensed with a heterocycle even if the heterocycle itself does not exhibit aromaticity.

[0049] Among aromatic heterocyclic compounds, specific examples of compounds in which the heterocycle itself exhibits aromaticity include oxadiazole, thiadiazole, thiazole, oxazole, thiophene, pyrrole, phosphole, furan, pyridine, pyrazine, pyrimidine, triazine, pyridazine, quinoline, isoquinoline, carbazole, and dibenzophosphole.

[0050] Among aromatic heterocyclic compounds, specific examples of compounds in which the heterocycle itself does not exhibit aromaticity and an aromatic ring is condensed with the heterocycle include phenoxazine, phenothiazine, dibenzoborole, dibenzosilole, and benzopyran.

[0051] The p-valent heterocyclic group may have a substituent. The number of carbon atoms in the p-valent heterocyclic group is usually 2 to 60, and preferably 2 to 20, not including the number of carbon atoms in the substituent.

[0052] Examples of monovalent heterocyclic groups include monovalent aromatic heterocyclic groups (e.g., thienyl, pyrrolyl, furyl, pyridyl, quinolyl, isoquinolyl, pyrimidinyl, and triazinyl groups), monovalent non-aromatic heterocyclic groups (e.g., piperidyl and piperazyl groups), and groups in which hydrogen atoms in these groups are substituted with substituents such as alkyl groups, alkyloxy groups, and fluorine atoms.

[0053] The term "substituted amino group" refers to an amino group having a substituent. The substituent of the amino group is preferably an alkyl group, an aryl group, or a monovalent heterocyclic group. The number of carbon atoms of the substituted amino group is usually 2 to 30, not including the number of carbon atoms of the substituent.

[0054] Examples of the substituted amino group include dialkylamino groups (e.g., dimethylamino group, diethylamino group), and diarylamino groups (e.g., diphenylamino group, bis(4-methylphenyl)amino group, bis(4-tert-butylphenyl)amino group, bis(3,5-di-tert-butylphenyl)amino group).

[0055] The "acyl group" may have a substituent. The number of carbon atoms of the acyl group, not including the number of carbon atoms of the substituent, is usually 2 to 20, and preferably 2 to 18. Specific examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a benzoyl group, a trifluoroacetyl group, and a pentafluorobenzoyl group.

[0056] The term "imine residue" refers to an atomic group remaining after removing one hydrogen atom directly bonded to a carbon atom or nitrogen atom constituting a carbon-nitrogen double bond from an imine compound. The term "imine compound" refers to an organic compound having a carbon-nitrogen double bond in the molecule. Examples of imine compounds include aldimines, ketimines, and compounds in which a hydrogen atom bonded to a nitrogen atom constituting a carbon-nitrogen double bond in an aldimine is substituted with a substituent such as an alkyl group.

[0057] The number of carbon atoms in the imine residue is usually 2 to 20, and preferably 2 to 18. Examples of the imine residue include groups represented by the following structural formulas.

[0058] [ka]

[0059] The term "amide group" refers to an atomic group remaining after removing one hydrogen atom bonded to a nitrogen atom from an amide. The number of carbon atoms in the amide group is usually about 1 to 20, and preferably 1 to 18. Specific examples of the amide group include a formamide group, an acetamide group, a propioamide group, a butyroamide group, a benzamide group, a trifluoroacetamide group, a pentafluorobenzamide group, a diformamide group, a diacetamide group, a dipropioamide group, a dibutyroamide group, a dibenzamide group, a ditrifluoroacetamide group, and a dipentafluorobenzamide group.

[0060] The term "acid imide group" refers to an atomic group remaining after removing one hydrogen atom bonded to a nitrogen atom from an acid imide. The number of carbon atoms in the acid imide group is usually 4 to 20. Specific examples of the acid imide group include the groups shown below.

[0061] [ka]

[0062] The term "substituted oxycarbonyl group" refers to a group represented by R'-O-(C=O)-, where R' represents an alkyl group, an aryl group, an arylalkyl group, or a monovalent heterocyclic group. The substituted oxycarbonyl group usually has 2 to 60 carbon atoms, and preferably has 2 to 48 carbon atoms.

[0063] Specific examples of the substituted oxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a butoxycarbonyl group, an isobutoxycarbonyl group, a tert-butoxycarbonyl group, a pentyloxycarbonyl group, a hexyloxycarbonyl group, a cyclohexyloxycarbonyl group, a heptyloxycarbonyl group, an octyloxycarbonyl group, a 2-ethylhexyloxycarbonyl group, a nonyloxycarbonyl group, a decyloxycarbonyl group, a 3,7-dimethyloctyloxycarbonyl group, a dodecyloxycarbonyl group, a trifluoromethoxycarbonyl group, a pentafluoroethoxycarbonyl group, a perfluorobutoxycarbonyl group, a perfluorohexyloxycarbonyl group, a perfluorooctyloxycarbonyl group, a phenoxycarbonyl group, a naphthoxycarbonyl group, and a pyridyloxycarbonyl group.

[0064] The "alkylsulfonyl group" may be linear or branched. The alkylsulfonyl group may have a substituent. The number of carbon atoms in the alkylsulfonyl group is usually 1 to 30, not including the number of carbon atoms in the substituent. Specific examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, and a dodecylsulfonyl group.

[0065] The "*" in a chemical formula represents a bond.

[0066] "π-conjugated system" means a system in which π-electrons are delocalized across multiple bonds.

[0067] "(Meth)acrylic" includes acrylic, methacrylic, and combinations thereof.

[0068] In this specification, the term "ink composition" refers to a liquid composition used in a coating method and is not limited to a colored liquid. The term "coating method" refers to a method of forming a film using a liquid substance such as an ink composition.

[0069] The "ink composition" may be a solution, or a dispersion such as a dispersion, an emulsion, or a suspension.

[0070] 2. Ink Composition The ink composition of the present embodiment is an ink composition containing a p-type semiconductor material, an n-type semiconductor material, and a solvent, and the p-type semiconductor material has a z-average molecular weight of 5.0×10 5 The ink composition for use in producing a photoelectric conversion element comprises a polymer compound having a molecular weight of less than 1.0.

[0071] As described above, the ink composition of the present embodiment is an ink composition for producing a photoelectric conversion element, and is preferably an ink composition for forming an active layer. Components that may be contained in the ink composition of this embodiment will be specifically described below.

[0072] Here, the p-type semiconductor material includes at least one electron donor compound, and the n-type semiconductor material includes at least one electron acceptor compound. Whether the semiconductor material included in the ink composition functions as a p-type semiconductor material or an n-type semiconductor material can be relatively determined based on the value of the HOMO energy level or the value of the LUMO energy level of the selected compound.

[0073] The relationship between the HOMO and LUMO energy levels of the p-type semiconductor material and the HOMO and LUMO energy levels of the n-type semiconductor material can be appropriately set within a range in which the (solidified) film formed from the ink composition exhibits a desired function, such as a photoelectric conversion function or a photodetection function.

[0074] (1) p-type semiconductor material In this embodiment, the p-type semiconductor material may be a low molecular weight compound or a high molecular weight compound.

[0075] Examples of p-type semiconductor materials that are low molecular weight compounds include phthalocyanine, metal phthalocyanine, porphyrin, metal porphyrin, oligothiophene, tetracene, pentacene, and rubrene.

[0076] The p-type semiconductor material that may be contained in the ink composition of this embodiment preferably contains a π-conjugated polymer compound (also referred to as a DA-type conjugated polymer compound) having a donor-acceptor structure that includes a donor structural unit (also referred to as a D structural unit) and an acceptor structural unit (also referred to as an A structural unit).

[0077] Here, a donor building block is a building block that has an excess of π electrons, and an acceptor building block is a building block that has a π electron deficiency.

[0078] In this embodiment, the constituent units that can constitute the p-type semiconductor material include constituent units in which a donor constituent unit and an acceptor constituent unit are directly bonded, and further, constituent units in which a donor constituent unit and an acceptor constituent unit are bonded via any suitable spacer (group or constituent unit).

[0079] Examples of p-type semiconductor materials that are polymer compounds include polyvinylcarbazole and its derivatives, polysilane and its derivatives, polysiloxane derivatives containing an aromatic amine structure in the side chain or main chain, polyaniline and its derivatives, polythiophene and its derivatives, polypyrrole and its derivatives, polyphenylenevinylene and its derivatives, polythienylenevinylene and its derivatives, and polyfluorene and its derivatives. As the p-type semiconductor material, it is preferable to use a polymer compound that contains a structural unit having a thiophene skeleton.

[0080] From the viewpoint of further improving the stability of the ink composition and further improving the external quantum efficiency of the photoelectric conversion element, the p-type semiconductor material is preferably a polymer compound containing a constitutional unit represented by the following formula (I) and / or a constitutional unit represented by the following formula (II):

[0081] [ka]

[0082] In formula (I), Ar 1 and Ar 2 each independently represents a trivalent aromatic heterocyclic group which may have a substituent, and Z represents a group represented by any one of the following formulas (Z-1) to (Z-7).

[0083] [ka]

[0084] In formula (II), Ar 3 represents a divalent aromatic heterocyclic group.

[0085] [ka]

[0086] In the formulas (Z-1) to (Z-7), R is Hydrogen atom, Halogen atoms, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkenyl group which may have a substituent; a cycloalkenyl group which may have a substituent, an optionally substituted alkynyl group, a cycloalkynyl group which may be substituted, an optionally substituted aryl group, an alkyloxy group which may have a substituent; a cycloalkyloxy group which may be substituted; an optionally substituted aryloxy group, an optionally substituted alkylthio group, a cycloalkylthio group which may be substituted; an optionally substituted arylthio group; a monovalent heterocyclic group which may have a substituent, a substituted amino group which may have a substituent; an imine residue which may have a substituent; an amide group which may have a substituent; an acid imide group which may have a substituent; a substituted oxycarbonyl group which may have a substituent; Cyano group, Nitro group, -C(=O)-R c or -SO2-R d represents a group represented by R c and R d are each independently Hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an optionally substituted aryl group, an alkyloxy group which may have a substituent; a cycloalkyloxy group which may be substituted; an optionally substituted aryloxy group, or It represents a monovalent heterocyclic group which may have a substituent. In formulae (Z-1) to (Z-7), when there are two R's, the two R's may be the same or different.

[0087] R in the formulas (Z-1) to (Z-7) is preferably a hydrogen atom, an alkyl group, or an aryl group, more preferably a hydrogen atom or an alkyl group, still more preferably a hydrogen atom or an alkyl group having 1 to 40 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, and particularly preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. These groups may have a substituent. When multiple Rs are present, the multiple Rs may be the same or different from each other.

[0088] The constitutional unit represented by formula (I) is preferably a constitutional unit represented by the following formula (I-1).

[0089] [ka]

[0090] In formula (I-1), Z has the same meaning as defined above.

[0091] Examples of the constitutional unit represented by formula (I-1) include constitutional units represented by the following formulae (501) to (505).

[0092] [ka]

[0093] In the above formulae (501) to (505), R has the same meaning as above. When there are two R, the two R may be the same or different.

[0094] In the formula (II), Ar 3 The number of carbon atoms in the divalent aromatic heterocyclic group represented by the following formula is usually 2 to 60, preferably 4 to 60, and more preferably 4 to 20. 3 The divalent aromatic heterocyclic group represented by the formula (1) may have a substituent. 3Examples of the substituent that the divalent aromatic heterocyclic group represented by the formula (I) may have include a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a monovalent heterocyclic group, a substituted amino group, an acyl group, an imine residue, an amide group, an acid imide group, a substituted oxycarbonyl group, an alkenyl group, an alkynyl group, a cyano group, and a nitro group.

[0095] Ar 3 Examples of the divalent aromatic heterocyclic group represented by the formula (1) include groups represented by the following formulas (101) to (190).

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] In the formulae (101) to (190), R has the same meaning as above. When a plurality of Rs are present, the plurality of Rs may be the same or different.

[0101] As the constitutional unit represented by the formula (II), constitutional units represented by the following formulae (II-1) to (II-6) are preferred.

[0102] [ka]

[0103] In formulas (II-1) to (II-6), X1 and X 2 each independently represents an oxygen atom or a sulfur atom, and R has the same meaning as above. When there are multiple R, the multiple R may be the same or different.

[0104] From the viewpoint of availability of raw material compounds, X in formula (II-1) to formula (II-6) 1 and X 2 are preferably sulfur atoms.

[0105] The polymer compound that is a p-type semiconductor material may contain two or more types of structural units of formula (I), or may contain two or more types of structural units of formula (II).

[0106] From the viewpoint of improving solubility in a solvent, the polymer compound that is a p-type semiconductor material may contain a constitutional unit represented by the following formula (III).

[0107] [ka]

[0108] In formula (III), Ar 4 represents an arylene group.

[0109] Ar 4 The arylene group represented by the formula (I) means an atomic group remaining after removing two hydrogen atoms from an aromatic hydrocarbon which may have a substituent. The aromatic hydrocarbon also includes a compound having a condensed ring and a compound in which two or more rings selected from the group consisting of independent benzene rings and condensed rings are bonded directly or via a divalent group such as vinylene.

[0110] Examples of the substituent that the aromatic hydrocarbon may have include the same substituents as those exemplified above as the substituents that the heterocyclic compound may have.

[0111] The number of carbon atoms in the arylene group excluding the substituent is usually 6 to 60, and preferably 6 to 20. The number of carbon atoms in the arylene group including the substituent is usually 6 to 100.

[0112] Examples of the arylene group include a phenylene group (for example, those of the following formulae 1 to 3), a naphthalene-diyl group (for example, those of the following formulae 4 to 13), an anthracene-diyl group (for example, those of the following formulae 14 to 19), a biphenyl-diyl group (for example, those of the following formulae 20 to 25), a terphenyl-diyl group (for example, those of the following formulae 26 to 28), a fused ring compound group (for example, those of the following formulae 29 to 35), a fluorene-diyl group (for example, those of the following formulae 36 to 38), and a benzofluorene-diyl group (for example, those of the following formulae 39 to 46).

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] [ka]

[0121] In formulae 1 to 46, R has the same meaning as defined above. When there are a plurality of R, the plurality of R may be the same or different.

[0122] When a polymer compound as a p-type semiconductor material contains a constitutional unit represented by formula (I) and / or a constitutional unit represented by formula (II), the total amount of the constitutional unit represented by formula (I) and the constitutional unit represented by formula (II) is usually 20 to 100 mol % when the amount of all constitutional units contained in the polymer compound is taken as 100 mol %, and since this improves the charge transport property as a p-type semiconductor material, it is preferably 40 to 100 mol %, and more preferably 50 to 100 mol %.

[0123] Preferred specific examples of the polymer compound that is a p-type semiconductor material include polymer compounds represented by the following formulas P-1 to P-10.

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] [ka]

[0128] In the ink composition according to the present embodiment, the p-type semiconductor material has a z-average molecular weight of 5.0×105 This includes polymeric compounds having a molecular weight of less than 1.

[0129] In the ink composition according to the present embodiment, the p-type semiconductor material has a weight average molecular weight of 6.0×10 4 From the viewpoint of achieving both photoelectric conversion efficiency and filterability, it is preferable that the polymer compound has a z-average molecular weight of 5.0×10 5 and the weight average molecular weight is less than 6.0 × 10 4 It is more preferable that the polymer compound contains a polymer compound larger than 1.

[0130] In the ink composition according to the present embodiment, the z-average molecular weight (Mz) of the p-type semiconductor material is preferably 1.5×10 5 It is preferable that it is greater than .

[0131] In the ink composition according to the present embodiment, the polymer compound as the p-type semiconductor material has a weight average molecular weight of usually 1×10 3 ~5×10 5 From the viewpoint of improving solubility in a solvent, it is preferably 1×10 3 ~3×10 5 It is.

[0132] In this embodiment, the z-average molecular weight (Mz) and the weight-average molecular weight (Mw) are polystyrene-equivalent average molecular weights that can be measured by gel permeation chromatography (GPC) performed using any suitable conventionally known device.

[0133] The ink composition of the present embodiment may contain only one type of compound (polymer compound) that is a p-type semiconductor material, or may contain two or more types in any combination.

[0134] Here, the z-average molecular weight (Mz) is a weighted average molecular weight using the square of the molecular weight as the weight, and is a parameter that tends to be more easily influenced by the presence of molecules with higher molecular weights than the weight-average molecular weight (Mw).

[0135] In this embodiment, the z-average molecular weight (Mz) of the p-type semiconductor material, which is a polymer compound, can be adjusted to fall within the above-mentioned preferred range by setting the conditions in the synthesis process of the polymer compound to predetermined conditions.

[0136] Specifically, for example, in the synthesis process of the above-exemplified polymer compound, the z-average molecular weight (Mz) can be adjusted to within the above-mentioned preferred range by appropriately adjusting the charged composition (mixing ratio) of multiple types of monomers as raw materials, appropriately adjusting the amount of catalyst used, appropriately adjusting the concentration of the reaction solution, etc. More specifically, the z-average molecular weight (Mz) can be appropriately adjusted by referring to, for example, the review in "Network Polymer, 2009, 30, 261" or the like.

[0137] According to the ink composition of the present embodiment, which uses a p-type semiconductor material having a z-average molecular weight (Mz) as described above, filtration can be performed more reliably without trial and error and without clogging the filter in the production process, electrical defects such as insulation and short circuits can be made less likely to occur, and the production efficiency of the ink composition and therefore the production efficiency of the photoelectric conversion element can be further improved.

[0138] (2) n-type semiconductor material The n-type semiconductor material that can be contained in the ink composition of this embodiment may be a low molecular weight compound or a high molecular weight compound.

[0139] Examples of n-type semiconductor materials (electron-accepting compounds) that are low molecular weight compounds include oxadiazole derivatives, anthraquinodimethane and its derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, tetracyanoanthraquinodimethane and its derivatives, fluorenone derivatives, diphenyldicyanoethylene and its derivatives, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and its derivatives, C 60 Examples of such fullerenes include fullerene and its derivatives, fullerene derivatives (hereinafter sometimes referred to as fullerene compounds), as well as phenanthrene derivatives such as bathocuproine.

[0140] Examples of n-type semiconductor materials that are polymer compounds include polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof, polysiloxane derivatives having an aromatic amine structure in the side chain or main chain, polyaniline and derivatives thereof, polythiophene and derivatives thereof, polypyrrole and derivatives thereof, polyphenylenevinylene and derivatives thereof, polythienylenevinylene and derivatives thereof, polyquinoline and derivatives thereof, polyquinoxaline and derivatives thereof, and polyfluorene and derivatives thereof.

[0141] The n-type semiconductor material is preferably one or more selected from fullerene and fullerene derivatives, and more preferably a fullerene derivative.

[0142] An example of a fullerene is C 60 Fullerene, C 70 Fullerene, C 76 Fullerene, C 78 Fullerene and C 84 Examples of fullerene derivatives include derivatives of these fullerenes. The fullerene derivatives refer to compounds in which at least a part of the fullerene is modified.

[0143] Examples of fullerene derivatives include compounds represented by the following formula:

[0144] [ka]

[0145] During the ceremony, R a represents an alkyl group, an aryl group, a monovalent heterocyclic group, or a group having an ester structure. a may be the same or different from each other. R b represents an alkyl group or an aryl group. b may be the same or different from each other.

[0146] R a Examples of the group having an ester structure represented by the formula include groups represented by the formulas below.

[0147] [ka]

[0148] In the formula, u1 represents an integer of 1 to 6. u2 represents an integer of 0 to 6. R e represents an alkyl group, an aryl group, or a monovalent heterocyclic group.

[0149] C 60 Examples of fullerene derivatives include the following compounds:

[0150] [ka]

[0151] C 70 Examples of fullerene derivatives include the following compounds:

[0152] [ka]

[0153] Specific examples of fullerene derivatives include [6,6]-phenyl-C61 butyric acid methyl ester (C60PCBM), [6,6]-phenyl-C71 butyric acid methyl ester (C70PCBM), [6,6]-Phenyl C71 butyric acid methyl ester (C84PCBM), [6,6]-Phenyl C85 butyric acid methyl ester, and [6,6]-Thienyl C61 butyric acid methyl ester.

[0154] The n-type semiconductor material that can be contained in the ink composition of this embodiment includes a compound that is not a fullerene compound. In this specification, an n-type semiconductor material that is not a fullerene compound is referred to as a "non-fullerene compound." Many types of compounds are known as non-fullerene compounds, and any suitable non-fullerene compound known in the art can be used as the n-type semiconductor material in this embodiment.

[0155] The ink composition according to this embodiment may contain only one type of compound that is an n-type semiconductor material, or may contain multiple types of compounds.

[0156] In this embodiment, the non-fullerene compound that is an n-type semiconductor material is preferably a compound that includes a perylene tetracarboxylic diimide structure. Examples of the non-fullerene compound that includes a perylene tetracarboxylic diimide structure include compounds represented by the following formula:

[0157] [ka]

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] In the formula, R is as defined above. A plurality of R may be the same or different.

[0162] In this embodiment, the n-type semiconductor material preferably contains a compound represented by the following formula (V): The compound represented by the following formula (V) is a non-fullerene compound containing a perylene tetracarboxylic diimide structure.

[0163] [ka]

[0164] In the formula (V), R 1 represents a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkyloxy group, an optionally substituted cycloalkyloxy group, an optionally substituted aryl group, or an optionally substituted monovalent aromatic heterocyclic group. 1 may be the same or different from each other.

[0165] Preferably, there are multiple R 1 each independently represents an alkyl group which may have a substituent.

[0166] R 2represents a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkyloxy group, an optionally substituted cycloalkyloxy group, an optionally substituted aryl group, or an optionally substituted monovalent aromatic heterocyclic group. 2 may be the same or different.

[0167] Preferred examples of the compound represented by formula (V) include compounds represented by the following formula:

[0168] [ka]

[0169] In this embodiment, the n-type semiconductor material preferably contains a compound represented by the following formula (VI): A 1 -B 10 -A 2 (VI)

[0170] In formula (VI), A 1 and A 2 each independently represents an electron-withdrawing group; B 10 represents a group containing a π-conjugated system.

[0171] A 1 and A 2 Examples of the electron-withdrawing group include a group represented by -CH=C(-CN)2 and groups represented by the following formulae (a-1) to (a-9).

[0172] [ka]

[0173] In formulas (a-1) to (a-7), T represents a carbocyclic ring which may have a substituent, or a heterocyclic ring which may have a substituent. The carbocyclic ring and the heterocyclic ring may be a single ring or a condensed ring. When these rings have a plurality of substituents, the plurality of substituents may be the same or different.

[0174] Examples of the carbocycle that may have a substituent that is T include aromatic carbocycles. The carbocycle that may have a substituent that is T is preferably an aromatic carbocycle. Specific examples of the carbocycle that may have a substituent that is T include a benzene ring, a naphthalene ring, an anthracene ring, a tetracene ring, a pentacene ring, a pyrene ring, and a phenanthrene ring, preferably a benzene ring, a naphthalene ring, and a phenanthrene ring, more preferably a benzene ring and a naphthalene ring, and even more preferably a benzene ring. These rings may have a substituent.

[0175] Examples of the heterocycle that may have a substituent that is T include aromatic heterocycles, and preferably aromatic heterocycles. Specific examples of the heterocycle that may have a substituent that is T include pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, and thienothiophene ring, and preferably thiophene ring, pyridine ring, pyrazine ring, thiazole ring, and thienothiophene ring, and more preferably thiophene ring. These rings may have a substituent.

[0176] Examples of the substituent that the carbocycle or heterocycle represented by T may have include a halogen atom, an alkyl group, an alkyloxy group, an aryl group, and a monovalent heterocyclic group, and preferably a fluorine atom and / or an alkyl group having 1 to 6 carbon atoms.

[0177] X 4 , X 5 , and X 6each independently represents an oxygen atom, a sulfur atom, an alkylidene group, or a group represented by =C(-CN)2, and is preferably an oxygen atom, a sulfur atom, or a group represented by =C(-CN)2.

[0178] X 7 represents a hydrogen atom, a halogen atom, a cyano group, an optionally substituted alkyl group, an optionally substituted alkyloxy group, an optionally substituted aryl group, or a monovalent heterocyclic group.

[0179] R a1 , R a2 , R a3 , R a4 , and R a5 each independently represents a hydrogen atom, an optionally substituted alkyl group, a halogen atom, an optionally substituted alkyloxy group, an optionally substituted aryl group, or a monovalent heterocyclic group, and is preferably an optionally substituted alkyl group or an optionally substituted aryl group.

[0180] [ka]

[0181] In formula (a-8) and formula (a-9), R a6 and R a7 each independently represents a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted alkyloxy group, an optionally substituted cycloalkyloxy group, an optionally substituted monovalent aromatic carbocyclic group, or an optionally substituted monovalent aromatic heterocyclic group; a6 and R a7 may be the same or different.

[0182] A 1 and A 2The electron-withdrawing group represented by R is preferably a group represented by any one of the following formulae (a-1-1) to (a-1-4), (a-6-1) and (a-7-1), and more preferably a group represented by formula (a-1-1). a10 R each independently represents a hydrogen atom or a substituent, and preferably represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group which may have a substituent. a3 , R a4 , and R a5 each independently has the same meaning as defined above, and preferably each independently represents an alkyl group which may have a substituent or an aryl group which may have a substituent.

[0183] [ka]

[0184] B 10 Examples of the group containing a π-conjugated system include -(S 1 ) n1 -B 11 -(S 2 ) n2 - is an example of a group represented by the formula:

[0185] In this embodiment, the n-type semiconductor material is preferably a compound represented by the following formula (VII). A 1 -(S 1 ) n1 -B 11 -(S 2 ) n2 -A 2 (VII)

[0186] In formula (VII), A 1 and A 2 Each independently represents an electron-withdrawing group. 1 and A 2 Examples and preferred examples of the compound A in formula (VI) are 1 and A 2This is similar to the examples and preferred examples described above.

[0187] S 1 and S 2 each independently represents a divalent carbocyclic group which may have a substituent, a divalent heterocyclic group which may have a substituent, -C(R s1 )=C(R s2 )- (wherein R s1 and R s2 each independently represents a hydrogen atom, a substituent (preferably a hydrogen atom, a halogen atom, an optionally substituted alkyl group, or an optionally substituted monovalent heterocyclic group), or a group represented by -C≡C-.

[0188] S 1 and S 2 The optionally substituted divalent carbocyclic group and optionally substituted divalent heterocyclic group represented by the following formula may be a condensed ring. When the divalent carbocyclic group or divalent heterocyclic group has multiple substituents, the multiple substituents may be the same or different.

[0189] In formula (VII), n1 and n2 each independently represent an integer of 0 or more, preferably each independently represent 0 or 1, and more preferably both represent 0 or 1.

[0190] Examples of divalent carbocyclic groups include divalent aromatic carbocyclic groups. Examples of the divalent heterocyclic group include a divalent aromatic heterocyclic group. When the divalent aromatic carbocyclic group or divalent aromatic heterocyclic group is a fused ring, all of the rings constituting the fused ring may be fused rings having aromaticity, or only some of the fused rings may be fused rings having aromaticity.

[0191] S 1 and S 2 An example of this is the already mentioned Ar 3Examples of the divalent aromatic heterocyclic group represented by the formula (101) to (190) given above include groups represented by the formula (101) to (190), and these groups in which hydrogen atoms have been substituted with substituents.

[0192] S 1 and S 2 preferably each independently represents a group represented by the following formula (s-1) or (s-2).

[0193] [ka]

[0194] In formulas (s-1) and (s-2), X 3 represents an oxygen atom or a sulfur atom. R a10 is as defined above.

[0195] S 1 and S 2 are preferably, each independently, a group represented by formula (142), formula (148), or formula (184), or a group in which a hydrogen atom in these groups is substituted with a substituent, and more preferably a group represented by formula (142) or formula (184), or a group in which one hydrogen atom in the group represented by formula (184) is substituted with an alkyloxy group.

[0196] B 11 represents a fused ring group having two or more structures selected from the group consisting of carbocyclic structures and heterocyclic structures, which does not contain an ortho-peri fused structure and which may have a substituent.

[0197] B 11 The fused ring group represented by the following formula may include a structure in which two or more identical structures are fused together.

[0198] B 11 When the fused ring group represented by the following formula (I) has a plurality of substituents, the plurality of substituents may be the same or different.

[0199] B 11 Examples of the carbocyclic structure that can constitute the fused ring group represented by the following formula (Cy1) or (Cy2) include ring structures represented by the following formula (Cy1) or (Cy2).

[0200] [ka]

[0201] B 11 Examples of the heterocyclic structure that can constitute the fused ring group represented by the following formula (Cy3) to formula (Cy10) include ring structures represented by any of the following formulas (Cy3) to (Cy10).

[0202] [ka]

[0203] In formula (VII), B 11 is preferably a fused ring group having two or more structures selected from the group consisting of structures represented by the above formulae (Cy1) to (Cy10), which does not contain an ortho-peri fused structure and which may have a substituent. 11 may contain a structure in which two or more identical structures among the structures represented by formulae (Cy1) to (Cy10) are condensed.

[0204] B 11 is more preferably a fused ring group having two or more structures selected from the group consisting of structures represented by formulae (Cy1) to (Cy6) and (Cy8), which is a fused ring group not containing an ortho-peri fused structure and which may have a substituent.

[0205] B 11 The substituent that the fused ring group may have is preferably an alkyl group that may have a substituent, an aryl group that may have a substituent, an alkyloxy group that may have a substituent, or a monovalent heterocyclic group that may have a substituent. 11The aryl group which the fused ring group represented by the following formula (I) may have may be substituted with, for example, an alkyl group.

[0206] B 11 Examples of the fused ring group include groups represented by the following formulae (b-1) to (b-14) and groups in which the hydrogen atoms in these groups are substituted with substituents (preferably an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkyloxy group which may have a substituent, or a monovalent heterocyclic group which may have a substituent). 11 The fused ring group represented by the formula (b-2) or (b-3) below is preferably a group represented by the formula (b-2) or (b-3) below, or a group in which a hydrogen atom in such a group is substituted with a substituent (preferably an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkyloxy group which may have a substituent, or a monovalent heterocyclic group which may have a substituent), and a group represented by the formula (b-2) or (b-3) below is more preferable.

[0207] [ka]

[0208] [ka]

[0209] In formulas (b-1) to (b-14), R a10 is as defined above. In the formulas (b-1) to (b-14), there are multiple R a10 are each independently preferably an alkyl group which may have a substituent, or an aryl group which may have a substituent.

[0210] Examples of the compound represented by formula (VI) or formula (VII) include compounds represented by the following formulas:

[0211] [ka]

[0212] In the above formula, R is as defined above, and X represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group which may have a substituent. In the above formula, R is preferably a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted alkyloxy group.

[0213] Examples of the compound represented by formula (VI) or (VII) include compounds represented by the following formulas:

[0214] [ka]

[0215] In the ink composition of this embodiment, the n-type semiconductor material may further contain a combination of the fullerene and fullerene derivative (fullerene compound) already described, in addition to the non-fullerene compound.

[0216] A specific example of a suitable n-type semiconductor material in this embodiment is a compound represented by the following formula:

[0217] [ka]

[0218] [ka]

[0219] [ka]

[0220] (3) Solvent The ink composition of the present embodiment may contain an aromatic hydrocarbon as a solvent. The aromatic hydrocarbon may have a substituent. The aromatic hydrocarbon is preferably a compound capable of dissolving the p-type semiconductor material described above.

[0221] Examples of aromatic hydrocarbons that can be used as the solvent include toluene, xylene (e.g., o-xylene, m-xylene, p-xylene), trimethylbenzene (e.g., mesitylene, 1,2,4-trimethylbenzene (pseudocumene)), butylbenzene (e.g., n-butylbenzene, sec-butylbenzene, tert-butylbenzene), methylnaphthalene (e.g., 1-methylnaphthalene), 1,2,3,4-tetrahydronaphthalene (tetralin), indane, 1-chloronaphthalene, chlorobenzene, and dichlorobenzene (1,2-dichlorobenzene).

[0222] The solvent may consist of only one aromatic hydrocarbon or may consist of two or more aromatic hydrocarbons.

[0223] The aromatic hydrocarbon that can constitute the solvent is preferably one or more selected from the group consisting of toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2,4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methylnaphthalene, tetralin, 1-chloronaphthalene, chlorobenzene, and dichlorobenzene (1,2-dichlorobenzene), and more preferably toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2,4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methylnaphthalene, tetralin, indane, 1-chloronaphthalene, chlorobenzene, or dichlorobenzene (o-dichlorobenzene).

[0224] The ink composition of the present embodiment may contain an alkyl halide as a solvent. Examples of the alkyl halide that may be used as the solvent include chloroform.

[0225] The ink composition of the present embodiment preferably contains, as a solvent, one or more selected from the group consisting of toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2,4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methylnaphthalene, tetralin, indan, 1-chloronaphthalene, chlorobenzene, dichlorobenzene (1,2-dichlorobenzene), and chloroform.

[0226] In the ink composition of this embodiment, in addition to the above-mentioned solvents, further solvents may be used in combination.

[0227] In this embodiment, examples of the further solvent include an aromatic carbonyl compound, an aromatic ester compound, and a nitrogen-containing heterocyclic compound.

[0228] Examples of aromatic carbonyl compounds include acetophenone which may have a substituent, propiophenone which may have a substituent, butyrophenone which may have a substituent, cyclohexylphenone which may have a substituent, and benzophenone which may have a substituent.

[0229] Examples of aromatic ester compounds include methyl benzoate (methyl benzoate) which may have a substituent, ethyl benzoate which may have a substituent, propyl benzoate which may have a substituent, butyl benzoate which may have a substituent, isopropyl benzoate which may have a substituent, benzyl benzoate which may have a substituent, cyclohexyl benzoate which may have a substituent, and phenyl benzoate which may have a substituent.

[0230] Examples of the nitrogen-containing heterocyclic compound include pyridine which may have a substituent, quinoline which may have a substituent, quinoxaline which may have a substituent, 1,2,3,4-tetrahydroquinoline which may have a substituent, pyrimidine which may have a substituent, pyrazine which may have a substituent, and quinazoline which may have a substituent.

[0231] The nitrogen-containing heterocyclic compound may have a substituent directly bonded to the ring structure. Examples of the substituent that the ring structure of the nitrogen-containing heterocyclic compound (e.g., quinoline ring structure, 1,2,3,4-tetrahydroquinoline ring structure, quinoxaline ring structure) may have include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen group, and an alkylthio group.

[0232] Examples of the nitrogen-containing heterocyclic compound containing a pyridine ring structure include pyridine which may have a substituent, quinoline which may have a substituent, and isoquinoline which may have a substituent.

[0233] Examples of the nitrogen-containing cyclic compound containing a pyrazine ring structure include pyrazine which may have a substituent and quinoxaline which may have a substituent.

[0234] Examples of the nitrogen-containing cyclic compound containing a tetrahydropyridine ring structure include 1,2,3,4-tetrahydroquinoline which may have a substituent, and 1,2,3,4-tetrahydroisoquinoline which may have a substituent.

[0235] Examples of the nitrogen-containing cyclic compound containing a pyrimidine ring structure include pyrimidine which may have a substituent, and quinazoline which may have a substituent.

[0236] In the present embodiment, the solvent may further contain only one of an aromatic carbonyl compound, an aromatic ester compound, or a nitrogen-containing heterocyclic compound as an additional solvent, or may further contain two or more selected from these.

[0237] In this embodiment, it is preferable to use a solvent that does not contain halogen from the viewpoint of environmental protection.

[0238] (Weight ratio of solvent and further solvent) When the ink composition of the present embodiment contains the above-mentioned solvent and the above-mentioned additional solvent, the weight ratio of the solvent to the additional solvent (solvent / additional solvent) is preferably in the range of 80 / 20 to 99.9 / 0.1, from the viewpoint of further improving the solubility of the p-type semiconductor material and the n-type semiconductor material.

[0239] (Weight percentage of solvent in ink composition) The total weight of the solvent contained in the ink composition, when the total weight of the ink composition is 100% by mass, is preferably 90% by mass or more, more preferably 92% by mass or more, and even more preferably 95% by mass or more, from the viewpoint of further improving the solubility of the p-type semiconductor material and the n-type semiconductor material, and is preferably 99.9% by mass or less, from the viewpoint of increasing the concentrations of the p-type semiconductor material and the n-type semiconductor material in the ink composition and making it easier to form a layer of a certain thickness or more.

[0240] The ink composition may further contain an optional solvent in addition to the solvents and further solvents already described. When the total weight of all the solvents contained in the ink composition is 100% by weight, the content of the optional solvent is preferably 10% by weight or less, more preferably 5% by weight or less, and even more preferably 3% by weight or less. As the optional solvent, it is preferable to use a solvent having a boiling point higher than that of the further solvent.

[0241] (Concentration of p-type semiconductor material and n-type semiconductor material in the ink composition) The total concentration of the p-type semiconductor material and the n-type semiconductor material in the ink composition can be any suitable concentration depending on the required thickness of the functional layer (active layer), the desired properties, etc. The total concentration of the p-type semiconductor material and the n-type semiconductor material is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 0.01% by mass or more and 20% by mass or less, particularly preferably 0.01% by mass or more and 10% by mass or less, even more particularly preferably 0.01% by mass or more and 5% by mass or less, and especially preferably 0.1% by mass or more and 5% by mass or less.

[0242] In the ink composition, the p-type semiconductor material and the n-type semiconductor material may be dissolved or dispersed. In the ink composition, the p-type semiconductor material and the n-type semiconductor material are preferably at least partially dissolved, and more preferably completely dissolved.

[0243] (Weight ratio of p-type semiconductor material to n-type semiconductor material (p / n ratio)) The weight ratio of the p-type semiconductor material to the n-type semiconductor material (p-type semiconductor material / n-type semiconductor material) in the ink composition is preferably 1 / 9 or more, more preferably 1 / 5 or more, even more preferably 1 / 3 or more, preferably 9 / 1 or less, more preferably 5 / 1 or less, even more preferably 3 / 1 or less.

[0244] 3. Method for producing ink composition The method for producing an ink composition of this embodiment includes a step of filtering an ink composition prepared by selecting a p-type semiconductor material, an n-type semiconductor material, and a solvent as described above, through a filter having a pore size of 0.5 μm or less.

[0245] The method for producing an ink composition according to the present embodiment includes a preparation step of preparing a plurality of types of polymer compounds that are p-type semiconductor materials, and selecting a polymer compound having a z-average molecular weight of 5.0×10 5and a step of mixing the p-type semiconductor material and the n-type semiconductor material selected in the selection step with a solvent to produce an ink composition.

[0246] z-average molecular weight is 5.0×10 5 The selection process for selecting polymer compounds having a z-average molecular weight of less than 100 as p-type semiconductor materials can be a selection process for measuring the z-average molecular weight of the polymer compounds prepared in the preparation process, for example, by the measurement method already described, and selecting the polymer compounds based on the measured z-average molecular weight.

[0247] In this embodiment, the ink composition can be manufactured by any suitable method known in the art. In particular, when two or more kinds of solvents are used, for example, the method of preparing a mixed solvent by mixing the already described solvent and an additional solvent, and then adding a p-type semiconductor material and an n-type semiconductor material to the mixed solvent to manufacture, and further, a method of preparing a (first) composition by adding a p-type semiconductor material to a solvent, separately preparing a (second) composition by adding an n-type semiconductor material to an additional solvent, and mixing the obtained two or more kinds of compositions to prepare (manufacture), in other words, the step of preparing the composition includes a step of preparing two or more kinds of compositions, and the step of preparing the ink composition includes a step of mixing two or more kinds of compositions, and the like.

[0248] In preparing the ink composition, the solvent (and any further solvent) may be mixed with the p-type semiconductor material and the n-type semiconductor material by heating to a temperature equal to or lower than the boiling point of the solvent.

[0249] In this embodiment, the step of preparing the ink composition is preferably carried out under conditions of 0° C. or higher and 200° C. or lower, and more preferably under conditions of 0° C. or higher and 100° C. or lower.

[0250] In this embodiment, the step of filtering the prepared ink composition may be specifically carried out by mixing a solvent (and a further solvent) with a p-type semiconductor material and an n-type semiconductor material in preparing (producing) the ink composition, and then filtering the resulting mixture (ink composition) using a filter having a predetermined pore size in a conventional manner.

[0251] In this embodiment, examples of filters that can be used for filtration include filters made of cellulose acetate, glass fiber, and fluororesins such as polyvinylidene fluoride (PVdF) and polytetrafluoroethylene (PTFE).

[0252] In this embodiment, the pore size of the filter that can be used is preferably 1 μm or less, more preferably 0.5 μm or less, even more preferably 0.45 μm or less, preferably 0.1 μm or more, more preferably 0.4 μm or more, preferably 0.1 μm to 0.5 μm, and more preferably 0.1 μm to 0.5 μm, from the viewpoints of filter availability, filtration efficiency, and suppressing the occurrence of defects in the functional layer (active layer) to be formed.

[0253] 4. Uses of the ink composition The ink composition of the present embodiment is generally used to form a film containing a p-type semiconductor material and an n-type semiconductor material.

[0254] The ink composition of the present embodiment is preferably used for forming an active layer included in a photoelectric conversion element, and particularly preferably used for forming an active layer included in a photodetection element to which a reverse bias voltage is applied during use.

[0255] 5. Solidified film of ink composition After forming a film using the ink composition of this embodiment, the solvent is removed from the film to solidify the film, thereby forming a solidified film of the ink composition. The solidified film of the ink composition can be suitably used to form a functional layer, particularly an active layer, contained in a light detection element. The solidified film of the ink composition can be produced by any suitable production method.

[0256] In the present embodiment, the method for producing a solidified film of the ink composition includes a step (i) of applying the ink composition to a coating target to obtain a coating film, and a step (ii) of removing the solvent from the obtained coating film. Steps (i) and (ii) are described below.

[0257] [Step (i)] In step (i), the method for applying the ink composition to the coating target may be any of the conventionally known coating methods already described. In this embodiment, the coating method is preferably a slit coating method, a knife coating method, a spin coating method, a microgravure coating method, a gravure coating method, a bar coating method, an inkjet coating method, a nozzle coating method, or a capillary coating method, more preferably a slit coating method, a spin coating method, a capillary coating method, or a bar coating method, and even more preferably a slit coating method or a spin coating method.

[0258] In step (i), the ink composition is applied to any coating target. The ink composition can be applied to a functional layer that may be included in a photoelectric conversion element, such as an electrode (anode or cathode), an electron transport layer, or a hole transport layer, in a manufacturing process of the photoelectric conversion element.

[0259] [Step (ii)] In step (ii), any suitable method can be used to remove the solvent from the coating film of the ink composition formed in step (i). Examples of the method for removing the solvent include hot air drying, infrared heating drying, flash lamp annealing drying, and reduced pressure drying.

[0260] 6. Photoelectric conversion element (1) Photoelectric conversion element configuration The photoelectric conversion element according to this embodiment includes a first electrode, a second electrode, and an active layer provided between the first electrode and the second electrode, and the active layer is the solidified film already described. Hereinafter, a configuration example of the photoelectric conversion element of this embodiment will be specifically described with reference to the drawings.

[0261] FIG. 1 is a diagram illustrating a schematic configuration example of a photoelectric conversion element.

[0262] 1, the photoelectric conversion element 10 is provided on a support substrate 11. The photoelectric conversion element 10 includes a first electrode 12 provided in contact with the support substrate 11, an electron transport layer 13 provided in contact with the first electrode 12, an active layer 14 provided in contact with the electron transport layer 13, a hole transport layer 15 provided in contact with the active layer 14, and a second electrode 16 provided in contact with the hole transport layer 15. In this configuration example, a sealing member 17 is further provided in contact with the first electrode 16. Hereinafter, components that may be included in the photoelectric conversion element of this embodiment will be specifically described.

[0263] (substrate) A photoelectric conversion element is usually formed on a substrate (support substrate). In some cases, the element is further sealed by a substrate (sealing substrate). On the substrate, one of a pair of electrodes consisting of a first electrode and a second electrode is usually formed. The material of the substrate is not particularly limited as long as it is a material that is not chemically changed when a layer containing an organic compound is formed.

[0264] Examples of the material of the substrate include glass, plastic, polymer film, and silicon. When an opaque substrate is used, it is preferable that the electrode on the opposite side to the electrode provided on the opaque substrate side (in other words, the electrode on the side farther from the opaque substrate) is a transparent or semi-transparent electrode.

[0265] (electrode) The photoelectric conversion element includes a pair of electrodes, a first electrode and a second electrode. At least one of the first electrode and the second electrode is preferably a transparent or semitransparent electrode to allow light to enter.

[0266] Examples of materials for transparent or semitransparent electrodes include conductive metal oxide films and semitransparent metal thin films. Specific examples include conductive materials such as indium oxide, zinc oxide, tin oxide, and their composites, such as indium tin oxide (ITO), indium zinc oxide (IZO), and NESA, as well as gold, platinum, silver, and copper. Preferred materials for transparent or semitransparent electrodes are ITO, IZO, and tin oxide. Also, transparent conductive films using organic compounds such as polyaniline and its derivatives, and polythiophene and its derivatives as materials may be used as electrodes. The transparent or semitransparent electrode may be either the first electrode or the second electrode.

[0267] If one of the pair of electrodes is transparent or semi-transparent, the other electrode may be an electrode with low light transmittance. Examples of the material of the electrode with low light transmittance include metals and conductive polymers. Specific examples of the material of the electrode with low light transmittance include metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, and ytterbium, and alloys of two or more of these metals, or alloys of one or more of these metals with one or more metals selected from the group consisting of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, and tin, graphite, graphite intercalation compounds, polyaniline and its derivatives, and polythiophene and its derivatives. The alloys include magnesium-silver alloys, magnesium-indium alloys, magnesium-aluminum alloys, indium-silver alloys, lithium-aluminum alloys, lithium-magnesium alloys, lithium-indium alloys, and calcium-aluminum alloys.

[0268] (active layer) The photoelectric conversion element of this embodiment includes, as an active layer, a solidified film of the ink composition described above. The active layer of this embodiment has a bulk heterojunction structure.

[0269] In this embodiment, the thickness of the active layer is not particularly limited. The thickness of the active layer can be any suitable thickness, for example, taking into consideration the balance between suppressing dark current and extracting the generated photocurrent. The thickness of the active layer is preferably 100 nm or more, more preferably 100 nm or more, and even more preferably 200 nm or more, particularly from the viewpoint of further reducing dark current. In addition, the thickness of the active layer is preferably 5 μm or less, more preferably 1 μm or less, and even more preferably 600 nm or less.

[0270] (Middle class) As shown in FIG. 1, the photoelectric conversion element of this embodiment preferably includes an intermediate layer (buffer layer) such as a charge transport layer (electron transport layer, hole transport layer, electron injection layer, hole injection layer) as a component for improving characteristics such as photoelectric conversion efficiency.

[0271] Examples of materials used for the intermediate layer include metals such as calcium, inorganic oxide semiconductors such as molybdenum oxide and zinc oxide, and a mixture of PEDOT (poly(3,4-ethylenedioxythiophene)) and PSS (poly(4-styrenesulfonate)) (PEDOT:PSS).

[0272] The intermediate layer can be formed by any suitable conventional method, such as a vacuum deposition method or a coating method similar to the method for forming the active layer.

[0273] As shown in Fig. 1, the photoelectric conversion element of this embodiment preferably includes an electron transport layer between the first electrode and the active layer. The electron transport layer has a function of transporting electrons from the active layer to the electrode. In another embodiment, the photoelectric conversion element does not need to include an electron transport layer.

[0274] The electron transport layer provided in contact with the first electrode may be referred to as an electron injection layer. The electron transport layer (electron injection layer) provided in contact with the first electrode has a function of promoting the injection of electrons into the first electrode. The electron transport layer (electron injection layer) may be in contact with the active layer.

[0275] The electron transport layer contains an electron transporting material, such as polyalkyleneimine and its derivatives, polymer compounds containing a fluorene structure, metals such as calcium, and metal oxides.

[0276] Examples of polyalkyleneimine and its derivatives include polymers obtained by polymerizing one or more alkyleneimines having 2 to 8 carbon atoms, particularly alkyleneimines having 2 to 4 carbon atoms, such as ethyleneimine, propyleneimine, butyleneimine, dimethylethyleneimine, pentyleneimine, hexyleneimine, heptyleneimine, and octyleneimine, by a conventional method, and polymers obtained by reacting them with various compounds to chemically modify them. As polyalkyleneimine and its derivatives, polyethyleneimine (PEI) and ethoxylated polyethyleneimine (PEIE) are preferred.

[0277] Examples of polymer compounds containing a fluorene structure include poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-ortho-2,7-(9,9'-dioctylfluorene)] (PFN) and PFN-P2.

[0278] Examples of metal oxides include zinc oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, titanium oxide, and niobium oxide. As the metal oxide, a metal oxide containing zinc is preferable, and among them, zinc oxide is preferable.

[0279] Other examples of electron transporting materials include poly(4-vinylphenol) and perylene diimide.

[0280] The photoelectric conversion element of this embodiment preferably has a configuration in which the intermediate layer is an electron transport layer, and the substrate (support substrate), the first electrode, the electron transport layer, the active layer, the hole transport layer, and the second electrode are laminated in this order so as to be in contact with each other.

[0281] As shown in Fig. 1, the photoelectric conversion element of this embodiment preferably includes a hole transport layer as an intermediate layer between the second electrode and the active layer. The hole transport layer has a function of transporting holes from the active layer to the second electrode. The hole transport layer may be in contact with the second electrode. The hole transport layer may be in contact with the active layer. In another embodiment, the photoelectric conversion element does not need to include a hole transport layer.

[0282] The hole transport layer provided in contact with the second electrode may be particularly called a hole injection layer. The hole transport layer (hole injection layer) provided in contact with the second electrode has a function of promoting the injection of holes generated in the active layer into the second electrode.

[0283] The hole transport layer includes a hole transport material, such as polythiophene and its derivatives, aromatic amine compounds, polymer compounds including structural units having aromatic amine residues, CuSCN, CuI, NiO, tungsten oxide (WO3), and molybdenum oxide (MoO3).

[0284] (Sealing member) The photoelectric conversion element of this embodiment preferably further includes a sealing member and is sealed with the sealing member to form a sealed body. The sealing member may be any suitable conventional member known in the art, and may be, for example, a combination of a glass substrate (sealing substrate) and a sealing material (adhesive) such as a UV-curable resin.

[0285] The sealing member may be a sealing layer having a layer structure of one or more layers. Examples of layers constituting the sealing layer include a gas barrier layer and a gas barrier film.

[0286] The sealing layer is preferably formed from a material having a property of blocking moisture (water vapor barrier property) or a property of blocking oxygen (oxygen barrier property). Examples of materials suitable for the sealing layer include organic materials such as trifluoropolyethylene, polytrifluorochloroethylene (PCTFE), polyimide, polycarbonate, polyethylene terephthalate, alicyclic polyolefin, and ethylene-vinyl alcohol copolymer, and inorganic materials such as silicon oxide, silicon nitride, aluminum oxide, and diamond-like carbon.

[0287] The sealing member is generally made of a material that can withstand a heat treatment that may be performed when the photoelectric conversion element is applied, for example, when the element is incorporated into a device of the application example described below.

[0288] (2) Method for manufacturing photoelectric conversion element The photoelectric conversion element of the present embodiment can be manufactured by any suitable manufacturing method known in the art. The photoelectric conversion element of the present embodiment may be manufactured by combining processes suitable for the materials selected for forming the components.

[0289] Hereinafter, as an embodiment of the present invention, a method for manufacturing a photoelectric conversion element having a configuration in which a substrate (support substrate), a first electrode, a hole transport layer, an active layer, an electron transport layer, and a second electrode are in contact with each other in this order will be described.

[0290] (Process of preparing the substrate) In this step, for example, a support substrate provided with a first electrode is prepared. Alternatively, a substrate provided with a conductive thin film formed from the electrode material already described can be purchased from the market, and the conductive thin film can be patterned to form the first electrode as necessary, thereby preparing a support substrate provided with the first electrode.

[0291] In the method for producing a photoelectric conversion element according to the present embodiment, the method for forming the first electrode on the support substrate is not particularly limited. The first electrode can be formed on the structure on which the first electrode is to be formed (e.g., support substrate, active layer, hole transport layer) by any suitable conventional method such as vacuum deposition, sputtering, ion plating, plating, or coating using the material already described.

[0292] (Hole transport layer forming process) The method for producing a photoelectric conversion element may include a step of forming a hole transport layer (hole injection layer) provided between the active layer and the first electrode.

[0293] The method for forming the hole transport layer is not particularly limited. From the viewpoint of simplifying the process for forming the hole transport layer, it is preferable to form the hole transport layer by any suitable coating method known in the art. The hole transport layer can be formed, for example, by a coating method using a coating liquid containing a material capable of forming the hole transport layer and a solvent as described above, or by a vacuum deposition method.

[0294] (Active layer formation process) In the method for producing a photoelectric conversion element according to the present embodiment, an active layer is formed on a hole transport layer. The active layer can be formed by any suitable conventionally known formation process. In the present embodiment, the active layer can be produced by a coating method using the ink composition already described.

[0295] The active layer can be formed in the same manner as the "solidified film" already described. In this embodiment, the active layer can be formed by a process including a step of applying an ink composition containing a p-type semiconductor material, an n-type semiconductor material, and a solvent onto a hole transport layer to form a coating film, and then a step of drying the coating film.

[0296] (Electron transport layer formation process) The method for manufacturing the photoelectric conversion element of this embodiment may include a step of forming an electron transport layer (electron injection layer) provided so as to be in contact with the active layer.

[0297] The method for forming the electron transport layer is not particularly limited. From the viewpoint of simplifying the process for forming the electron transport layer, it is preferable to form the electron transport layer by any suitable conventional vacuum deposition method.

[0298] (Step of forming second electrode) The method of forming the second electrode is not particularly limited. The second electrode can be formed by any suitable method known in the art, such as coating, vacuum deposition, sputtering, ion plating, plating, etc., using the above-mentioned electrode material. The photoelectric conversion element of this embodiment is manufactured by the above-mentioned steps.

[0299] (Sealing Body Forming Process) In forming the sealed body, in this embodiment, any suitable sealing material (adhesive) and substrate (sealing substrate) known in the art are used. Specifically, a sealing material such as a UV-curable resin is applied onto a support substrate so as to surround the periphery of the manufactured photoelectric conversion element, and then the support substrate and sealing substrate are bonded together without any gaps by the sealing material. Then, the photoelectric conversion element is sealed in the gap between the support substrate and the sealing substrate by a method such as UV light irradiation suitable for the selected sealing material, thereby obtaining a sealed body of the photoelectric conversion element.

[0300] (3) Uses of photoelectric conversion elements The photoelectric conversion element of this embodiment can be used in applications such as a photodetector element and a solar cell. More specifically, the photoelectric conversion element of this embodiment can generate a photocurrent by irradiating light from the transparent or semitransparent electrode side with a voltage (reverse bias voltage) applied between the electrodes, and can be operated as a photodetection element (photosensor). In addition, a plurality of photodetection elements can be integrated to be used as an image sensor. The photoelectric conversion element of this embodiment can be particularly suitably used as a photodetection element.

[0301] In addition, the photoelectric conversion element of the present embodiment can generate photovoltaic power between the electrodes when irradiated with light, and can operate as a solar cell. A solar cell module can also be formed by integrating a plurality of photoelectric conversion elements.

[0302] (4) Application examples of photoelectric conversion elements The photoelectric conversion element according to this embodiment can be suitably applied as a photodetector element to detection units provided in various electronic devices such as workstations, personal computers, portable information terminals, entrance and exit management systems, digital cameras, and medical equipment.

[0303] The photoelectric conversion element of this embodiment can be suitably applied to the image detection units (e.g., image sensors such as X-ray sensors) for solid-state imaging devices such as X-ray imaging devices and CMOS image sensors, detection units (e.g., near-infrared sensors) of biometric information authentication devices that detect predetermined characteristics of a part of a living body, such as fingerprint detection units, face detection units, vein detection units and iris detection units, and detection units of optical biosensors such as pulse oximeters, which are provided in the above-mentioned exemplary electronic devices.

[0304] The photoelectric conversion element of this embodiment can be suitably applied as an image detection section for a solid-state imaging device, and further to a time-of-flight (TOF) type distance measurement device.

[0305] In TOF distance measuring devices, the distance is measured by receiving the light reflected by the object to be measured using a photoelectric conversion element. Specifically, the distance to the object to be measured is calculated by detecting the flight time of the light emitted from the light source, which is reflected by the object to be measured and returns as reflected light. There are two types of TOF: direct TOF and indirect TOF. In the direct TOF method, the difference between the time when the light is emitted from the light source and the time when the reflected light is received by the photoelectric conversion element is directly measured, while in the indirect TOF method, the change in the amount of charge accumulation that depends on the flight time is converted into a time change to measure the distance. The distance measuring principle used in the indirect TOF method to obtain the flight time by charge accumulation includes the continuous wave (especially sinusoidal wave) modulation method, which obtains the flight time from the phase of the light emitted from the light source and the reflected light reflected by the object to be measured, and the pulse modulation method.

[0306] Below, examples of configurations of detection units to which the photoelectric conversion element of this embodiment can be suitably applied will be described with reference to the drawings, including an image detection unit for a solid-state imaging device and an image detection unit for an X-ray imaging device, a fingerprint detection unit and a vein detection unit for a biometric authentication device (e.g., a fingerprint authentication device or a vein authentication device), and an image detection unit for a TOF type distance measuring device (indirect TOF method).

[0307] (Image detector for solid-state imaging device) FIG. 2 is a diagram illustrating a schematic configuration example of an image detection unit for a solid-state imaging device.

[0308] The image detection unit 1 includes a CMOS transistor substrate 20, an interlayer insulating film 30 provided to cover the CMOS transistor substrate 20, a photoelectric conversion element 10 according to an embodiment of the present invention provided on the interlayer insulating film 30, an interlayer wiring portion 32 provided to penetrate the interlayer insulating film 30 and electrically connects the CMOS transistor substrate 20 and the photoelectric conversion element 10, a sealing layer 40 provided to cover the photoelectric conversion element 10, and a color filter 50 provided on the sealing layer 40.

[0309] The CMOS transistor substrate 20 has any suitable conventionally known configuration in a manner according to the design.

[0310] The CMOS transistor substrate 20 includes transistors, capacitors, and the like formed within the thickness of the substrate, and is equipped with functional elements such as CMOS transistor circuits (MOS transistor circuits) for implementing various functions.

[0311] Examples of the functional element include a floating diffusion, a reset transistor, an output transistor, and a selection transistor.

[0312] A signal readout circuit and the like are formed on the CMOS transistor substrate 20 using such functional elements and wiring.

[0313] The interlayer insulating film 30 can be made of any suitable insulating material known in the art, such as silicon oxide, insulating resin, etc. The interlayer wiring portion 32 can be made of any suitable conductive material known in the art (wiring material), such as copper, tungsten, etc. The interlayer wiring portion 32 can be, for example, a wiring in a hole formed simultaneously with the formation of a wiring layer, or a buried plug formed separately from the wiring layer.

[0314] The sealing layer 40 can be made of any suitable material known in the art, provided that it can prevent or suppress the penetration of harmful substances such as oxygen and water that may cause functional deterioration of the photoelectric conversion element 10. The sealing layer 40 can have a structure similar to that of the sealing member 17 already described.

[0315] The color filter 50 may be, for example, a primary color filter made of any suitable material known in the art and adapted to the design of the image detection unit 1. Also, the color filter 50 may be a complementary color filter that can be made thinner than the primary color filter. The complementary color filter may be, for example, a combination of three types of color filters: (yellow, cyan, magenta), three types of color filters: (yellow, cyan, transparent), three types of color filters: (yellow, transparent, magenta), and three types of color filters: (transparent, cyan, magenta). These may be arranged in any suitable manner adapted to the design of the photoelectric conversion element 10 and the CMOS transistor substrate 20, provided that color image data can be generated.

[0316] The light received by the photoelectric conversion element 10 through the color filter 50 is converted by the photoelectric conversion element 10 into an electrical signal corresponding to the amount of light received, and is output to the outside of the photoelectric conversion element 10 via the electrode as a received light signal, i.e., an electrical signal corresponding to the object to be imaged.

[0317] Next, the light receiving signal output from the photoelectric conversion element 10 is input to the CMOS transistor substrate 20 via the interlayer wiring section 32, read out by a signal readout circuit built into the CMOS transistor substrate 20, and subjected to signal processing by any suitable conventionally known functional section not shown in the figure, thereby generating image information based on the imaging target.

[0318] (Fingerprint detection section) FIG. 3 is a diagram illustrating a configuration example of a fingerprint detection unit that is integrally configured with the display device.

[0319] The display device 2 of the mobile information terminal includes a fingerprint detection unit 100 having a photoelectric conversion element 10 according to an embodiment of the present invention as its main component, and a display panel unit 200 provided on the fingerprint detection unit 100 and displaying a predetermined image.

[0320] In this configuration example, the fingerprint detection section 100 is provided in an area that coincides with the display area 200a of the display panel section 200. In other words, the display panel section 200 is laminated integrally above the fingerprint detection section 100.

[0321] When fingerprint detection is performed only in a portion of the display area 200a, the fingerprint detection unit 100 may be provided so as to correspond to only that portion of the display area 200a.

[0322] The fingerprint detection unit 100 includes the photoelectric conversion element 10 according to the embodiment of the present invention as a functional unit that performs an essential function. The fingerprint detection unit 100 may include any suitable conventionally known members such as a protection film, a support substrate, a sealing substrate, a sealing member, a barrier film, a bandpass filter, and an infrared cut film, which are not shown, in a form corresponding to a design that obtains desired characteristics. The fingerprint detection unit 100 may also adopt the configuration of the image detection unit already described.

[0323] The photoelectric conversion elements 10 may be included in the display region 200a in any manner. For example, a plurality of photoelectric conversion elements 10 may be arranged in a matrix.

[0324] As already described, the photoelectric conversion element 10 is provided on the support substrate 11, and the support substrate 11 is provided with electrodes (first electrodes or second electrodes) in a matrix pattern, for example.

[0325] The light received by the photoelectric conversion element 10 is converted by the photoelectric conversion element 10 into an electrical signal according to the amount of light received, and is output via the electrodes to the outside of the photoelectric conversion element 10 as a received light signal, i.e., an electrical signal corresponding to the captured fingerprint.

[0326] In this configuration example, the display panel unit 200 is configured as an organic electroluminescence display panel (organic EL display panel) including a touch sensor panel. The display panel unit 200 may be configured with any suitable display panel having a conventionally known configuration, such as a liquid crystal display panel including a light source such as a backlight, instead of an organic EL display panel.

[0327] The display panel unit 200 is provided on the fingerprint detection unit 100 already described. The display panel unit 200 includes an organic electroluminescence element (organic EL element) 220 as a functional unit that performs an essential function. The display panel unit 200 may further include any suitable conventionally known member such as a substrate (support substrate 210 or sealing substrate 240) such as a glass substrate, a sealing member, a barrier film, a polarizing plate such as a circular polarizing plate, and a touch sensor panel 230 in a mode corresponding to desired characteristics.

[0328] In the configuration example described above, the organic EL element 220 is used as a light source for the pixels in the display area 200a, and is also used as a light source for capturing an image of a fingerprint in the fingerprint detection unit 100.

[0329] Here, the operation of the fingerprint detection unit 100 will be briefly described. When fingerprint authentication is performed, the fingerprint detection unit 100 detects a fingerprint using light emitted from the organic EL element 220 of the display panel unit 200. Specifically, the light emitted from the organic EL element 220 passes through components present between the organic EL element 220 and the photoelectric conversion element 10 of the fingerprint detection unit 100, and is reflected by the skin (finger surface) of the fingertip of a finger placed in contact with the surface of the display panel unit 200 within the display area 200a. At least a part of the light reflected by the finger surface passes through components present therebetween and is received by the photoelectric conversion element 10, and is converted into an electrical signal according to the amount of light received by the photoelectric conversion element 10. Then, image information about the fingerprint on the finger surface is composed from the converted electrical signal.

[0330] The portable information terminal equipped with the display device 2 performs fingerprint authentication by comparing the obtained image information with pre-recorded fingerprint data for fingerprint authentication through any suitable step known in the art.

[0331] (Image detector for X-ray imaging device) FIG. 4 is a diagram illustrating a schematic configuration example of an image detection unit for an X-ray imaging device.

[0332] The image detection unit 1 for an X-ray imaging device includes a CMOS transistor substrate 20, an interlayer insulating film 30 provided to cover the CMOS transistor substrate 20, a photoelectric conversion element 10 according to an embodiment of the present invention provided on the interlayer insulating film 30, an interlayer wiring portion 32 provided to penetrate the interlayer insulating film 30 and electrically connects the CMOS transistor substrate 20 and the photoelectric conversion element 10, a sealing layer 40 provided to cover the photoelectric conversion element 10, a scintillator 42 provided on the sealing layer 40, a reflective layer 44 provided to cover the scintillator 42, and a protective layer 46 provided to cover the reflective layer 44.

[0333] The CMOS transistor substrate 20 has any suitable conventionally known configuration in a manner according to the design.

[0334] The CMOS transistor substrate 20 includes transistors, capacitors, and the like formed within the thickness of the substrate, and is equipped with functional elements such as CMOS transistor circuits (MOS transistor circuits) for implementing various functions.

[0335] Examples of the functional element include a floating diffusion, a reset transistor, an output transistor, and a selection transistor.

[0336] A signal readout circuit and the like are formed on the CMOS transistor substrate 20 using such functional elements and wiring.

[0337] The interlayer insulating film 30 can be made of any suitable insulating material known in the art, such as silicon oxide, insulating resin, etc. The interlayer wiring portion 32 can be made of any suitable conductive material known in the art (wiring material), such as copper, tungsten, etc. The interlayer wiring portion 32 can be, for example, a wiring in a hole formed simultaneously with the formation of a wiring layer, or a buried plug formed separately from the wiring layer.

[0338] The sealing layer 40 can be made of any suitable material known in the art, provided that it can prevent or suppress the penetration of harmful substances such as oxygen and water that may cause functional deterioration of the photoelectric conversion element 10. The sealing layer 40 can have a structure similar to that of the sealing member 17 already described.

[0339] The scintillator 42 can be made of any suitable conventional material that is known in accordance with the design of the image detection unit 1 for the X-ray imaging device. Suitable examples of materials for the scintillator 42 include inorganic crystals of inorganic materials such as CsI (cesium iodide), NaI (sodium iodide), ZnS (zinc sulfide), GOS (gadolinium oxysulfide), and GSO (gadolinium silicate), organic crystals of organic materials such as anthracene, naphthalene, and stilbene, organic liquids in which organic materials such as diphenyloxazole (PPO) and terphenyl (TP) are dissolved in organic solvents such as toluene, xylene, and dioxane, gases such as xenon and helium, and plastics.

[0340] The above components can be arranged in any suitable manner corresponding to the design of the photoelectric conversion element 10 and the CMOS transistor substrate 20, provided that the scintillator 42 can convert the incident X-rays into light having a wavelength centered in the visible range and generate image data.

[0341] The reflective layer 44 reflects the light converted by the scintillator 42. The reflective layer 44 can reduce the loss of the converted light and increase the detection sensitivity. The reflective layer 44 can also block light that is directly incident from the outside.

[0342] The protective layer 46 can be made of any suitable material known in the art, provided that it can prevent or suppress the penetration of harmful substances such as oxygen and water that may cause the functionality of the scintillator 42 to deteriorate.

[0343] Here, the operation of the image detection unit 1 for the X-ray imaging device having the above configuration will be briefly described.

[0344] When radiation energy such as X-rays or gamma rays is incident on the scintillator 42, the scintillator 42 absorbs the radiation energy and converts it into light (fluorescence) with wavelengths in the ultraviolet to infrared range centered on the visible range. The light converted by the scintillator 42 is then received by the photoelectric conversion element 10.

[0345] In this way, the light received by the photoelectric conversion element 10 via the scintillator 42 is converted by the photoelectric conversion element 10 into an electrical signal according to the amount of received light, and is output via the electrodes to the outside of the photoelectric conversion element 10 as a received light signal, i.e., an electrical signal corresponding to the imaging target. The radiation energy (X-rays) to be detected may be incident from either the scintillator 42 side or the photoelectric conversion element 10 side.

[0346] Next, the light receiving signal output from the photoelectric conversion element 10 is input to the CMOS transistor substrate 20 via the interlayer wiring section 32, read out by a signal readout circuit built into the CMOS transistor substrate 20, and subjected to signal processing by any suitable conventionally known functional section not shown in the figure, thereby generating image information based on the imaging target.

[0347] (Vein detection section) FIG. 5 is a diagram illustrating a configuration example of a vein detection unit for use in a vein authentication device. The vein detection unit 300 for the vein authentication device is composed of a cover unit 306 that defines an insertion unit 310 into which a finger to be measured (e.g., the fingertip of one or more fingers, the finger and the palm) is inserted during measurement, a light source unit 304 that is provided in the cover unit 306 and irradiates light onto the measurement object, a photoelectric conversion element 10 that receives the light irradiated from the light source unit 304 through the measurement object, a support substrate 11 that supports the photoelectric conversion element 10, and a glass substrate 302 that is disposed to face each other across the support substrate 11 and the photoelectric conversion element 10, is spaced a predetermined distance from the cover unit 306, and defines the insertion unit 306 together with the cover unit 306.

[0348] In this configuration example, the light source unit 304 is configured integrally with the cover unit 306 so as to sandwich and separate the photoelectric conversion element 10 from the object to be measured during use, but the light source unit 304 does not necessarily have to be positioned on the cover unit 306 side.

[0349] Provided that the light from the light source unit 304 can be efficiently irradiated onto the measurement object, for example, a reflection type imaging method in which the measurement object is irradiated from the photoelectric conversion element 10 side may be used.

[0350] The vein detection unit 300 includes the photoelectric conversion element 10 according to the embodiment of the present invention as a functional unit that performs an essential function. The vein detection unit 300 may include any suitable conventionally known members such as a protection film, a sealing member, a barrier film, a bandpass filter, a near-infrared transmission filter, a visible light blocking film, and a finger placement guide, all of which are not shown, in a form corresponding to a design that obtains desired characteristics. The vein detection unit 300 may also employ the configuration of the image detection unit 1 already described.

[0351] The photoelectric conversion element 10 may be included in any manner. For example, a plurality of photoelectric conversion elements 10 may be arranged in a matrix.

[0352] As already described, the photoelectric conversion element 10 is provided on the support substrate 11, and the support substrate 11 is provided with electrodes (first electrodes or second electrodes) in a matrix pattern, for example.

[0353] The light received by the photoelectric conversion element 10 is converted by the photoelectric conversion element 10 into an electrical signal according to the amount of received light, and is output to the outside of the photoelectric conversion element 10 via the electrodes as a received light signal, i.e., an electrical signal corresponding to the imaged vein.

[0354] During vein detection (during use), the measurement target may or may not be in contact with glass substrate 302 on the photoelectric conversion element 10 side.

[0355] Here, the operation of the vein detection unit 300 will be briefly described. During vein detection, the vein detection unit 300 detects the vein pattern of the measurement object using light emitted from the light source unit 304. Specifically, the light emitted from the light source unit 304 passes through the measurement object and is converted into an electrical signal according to the amount of light received by the photoelectric conversion element 10. Then, image information of the vein pattern of the measurement object is composed from the converted electrical signal.

[0356] In the vein authentication device, vein authentication is performed by comparing the obtained image information with pre-recorded vein data for vein authentication through any suitable step known in the art.

[0357] (Image detector for TOF distance measuring device) FIG. 6 is a diagram showing a schematic configuration example of an image detection unit for an indirect type TOF distance measuring device.

[0358] The image detection unit 400 for a TOF type distance measuring device comprises a CMOS transistor substrate 20, an interlayer insulating film 30 arranged to cover the CMOS transistor substrate 20, a photoelectric conversion element 10 according to an embodiment of the present invention arranged on the interlayer insulating film 30, two floating diffusion layers 402 arranged at a distance to sandwich the photoelectric conversion element 10, an insulating layer 40 arranged to cover the photoelectric conversion element 10 and the floating diffusion layer 402, and two photogates 404 arranged on the insulating layer 40 and arranged at a distance from each other.

[0359] A part of the insulating layer 40 is exposed from the gap between the two spaced apart photogates 404, and the remaining area is shielded from light by a light shielding portion 406. The CMOS transistor substrate 20 and the floating diffusion layer 402 are electrically connected by an interlayer wiring portion 32 provided to penetrate the interlayer insulating film 30.

[0360] The interlayer insulating film 30 can be made of any suitable insulating material known in the art, such as silicon oxide, insulating resin, etc. The interlayer wiring portion 32 can be made of any suitable conductive material known in the art (wiring material), such as copper, tungsten, etc. The interlayer wiring portion 32 can be, for example, a wiring in a hole formed simultaneously with the formation of a wiring layer, or a buried plug formed separately from the wiring layer.

[0361] In this configuration example, the insulating layer 40 may be of any suitable conventionally known configuration, such as a field oxide film made of silicon oxide.

[0362] Photogate 404 may be constructed from any suitable material known in the art, such as polysilicon.

[0363] The image detection unit 400 for the TOF type distance measuring device includes the photoelectric conversion element 10 according to the embodiment of the present invention as a functional unit that performs an essential function. The image detection unit 400 for the TOF type distance measuring device may include any suitable conventionally known members such as a protection film, a support substrate, a sealing substrate, a sealing member, a barrier film, a bandpass filter, and an infrared cut film, which are not shown, in a form corresponding to a design that obtains desired characteristics.

[0364] Here, the operation of the image detection unit 400 for the TOF type distance measuring device will be briefly described.

[0365] Light is emitted from a light source, reflected from the object to be measured, and the reflected light is received by the photoelectric conversion element 10. Two photogates 404 are provided between the photoelectric conversion element 10 and the floating diffusion layer 402, and by applying pulses alternately, the signal charge generated by the photoelectric conversion element 10 is transferred to one of the two floating diffusion layers 402, and the charge is accumulated in the floating diffusion layer 402. If the light pulse arrives so as to span equally with respect to the timing at which the two photogates 404 are opened, the amount of charge accumulated in the two floating diffusion layers 402 will be equal. If the light pulse arrives at one photogate 404 with a delay from the timing at which the light pulse arrives at the other photogate 404, a difference occurs in the amount of charge accumulated in the two floating diffusion layers 402.

[0366] The difference in the amount of charge accumulated in the floating diffusion layers 402 depends on the delay time of the optical pulse. The distance L to the measurement target is expressed as L=(1 / 2)ctd using the round-trip time td of light and the speed of light c. Therefore, if the delay time can be estimated from the difference in the amount of charge in the two floating diffusion layers 402, the distance to the measurement target can be calculated.

[0367] The amount of light received by the photoelectric conversion element 10 is converted into an electrical signal as the difference between the amounts of charge accumulated in the two floating diffusion layers 402, and is output to the outside of the photoelectric conversion element 10 as a received light signal, i.e., an electrical signal corresponding to the object to be measured.

[0368] Next, the received light signal output from the floating diffusion layer 402 is input to the CMOS transistor substrate 20 via the interlayer wiring section 32, read out by a signal readout circuit built into the CMOS transistor substrate 20, and subjected to signal processing by any suitable conventionally known functional section not shown in the figure, thereby generating distance information based on the object to be measured.

[0369] 7. Light detection element As described above, the photoelectric conversion element of the present embodiment can have a light detection function of converting irradiated light into an electrical signal according to the amount of received light and outputting the electrical signal to an external circuit via an electrode. Therefore, the photoelectric conversion element according to the embodiment of the present invention can be particularly suitably applied as a light detection element having a light detection function. Here, the light detection element of the present embodiment may be a photoelectric conversion element itself, or may further include a functional element for voltage control in addition to the photoelectric conversion element. EXAMPLES

[0370] The present invention will be described in more detail below with reference to examples, which are not intended to limit the scope of the present invention.

[0371] <Semiconductor materials> As material P-1, a material synthesized with reference to the method described in WO2013 / 051676 was used. As the material P-2, PCE-10 manufactured by 1-material Co., Ltd. was purchased from the market and used. As material N-1, a product name: E100 manufactured by Frontier Carbon Co., Ltd. was purchased from the market and used. As material N-2, DiPDI (trade name, manufactured by 1-material Co., Ltd.) was purchased from the market and used. As material N-3, a product manufactured by 1-material Co., Ltd. under the trade name ITIC was purchased from the market and used.

[0372] The specific structures of the p-type semiconductor materials P-1 and P-2 and the n-type semiconductor materials N-1 to N-3 used in this example are shown in Tables 1 and 2 below.

[0373] [Table 1]

[0374] [Table 2]

[0375] <Molecular weight measurement> The z-average molecular weight (Mz) and weight-average molecular weight (Mw) of the p-type semiconductor material were determined as polystyrene-equivalent z-average molecular weight (Mz) and weight-average molecular weight (Mw) by gel permeation chromatography (GPC) (Shimadzu Corporation, LC-20AT). A specific description will be given below.

[0376] The mobile phase for GPC was o-dichlorobenzene, and the flow rate was 1.0 mL / min. The column used was Shodex KD-806M manufactured by Showa Denko K.K., and the guard column used was Shodex KD-G manufactured by Showa Denko K.K.

[0377] The detectors used were a UV-vis detector (Shimadzu Corporation, SPD-M20A) and a differential refractive index detector (Shimadzu Corporation, RID-10A).

[0378] The compound (polymer) to be measured was mixed into 1-chloronaphthalene as a solvent so as to have a concentration of 0.05% by mass, and dissolved by stirring at 80° C. for 2 hours to obtain a solution.

[0379] The resulting solution was injected as a sample in an amount of 10 μL into the above-mentioned measuring device (GPC) to measure the z-average molecular weight (Mz) and the weight-average molecular weight (Mw).

[0380] <Example 1> [Preparation of Ink Composition] Material P-1 as a p-type semiconductor material was mixed with 1,2,3,4-tetrahydronaphthalene so that the content was 0.8 mass% relative to the total mass of the ink composition, and material N-1 as an n-type semiconductor material was mixed with the ink composition so that the content was 1.6 mass% relative to the mass of the ink composition, and the mixture was stirred at 60°C for 6 hours to obtain ink composition (I-1).

[0381] [Filterability test of ink composition] The ink composition prepared as above was used to carry out a filterability test for the ink composition. Specifically, a filter having a predetermined pore size was used to evaluate whether the ink composition could pass through the filter. That is, when the ink composition could pass through the filter and could be filtered, the filterability was evaluated as good (◯), and when the ink composition could not pass through the filter and the filter was clogged, the filterability was evaluated as poor (×).

[0382] More specifically, 10 g of the ink composition (I-1) prepared as described above was added to a stainless steel holder (KS047, manufactured by Advantec Toyo Co., Ltd.) equipped with a PTFE filter having a pore size of 0.5 μm, and a filtration test was carried out.

[0383] As a result, the ink composition I-1 was able to pass through the PTFE filter without clogging it, and the filtration was completed. Therefore, the filterability was evaluated as good (○). The results are also shown in Table 1.

[0384] <Examples 2 to 6 and Comparative Example 1> Except for using a material P-1 having the z-average molecular weight (Mz) and weight-average molecular weight (Mw) shown in Table 3 below as the p-type semiconductor material, the preparation of an ink composition and the filtration test were carried out in the same manner as in Example 1. The results are also shown in Table 3 below.

[0385] [Table 3]

[0386] <Example 7> [Ink composition] An ink composition (I-8) was prepared in the same manner as in Example 1, except that material P-1 was used as a p-type semiconductor material so that the content of material P-1 was 2.0 mass % relative to the total mass of the ink composition, and material N-1 was used as an n-type semiconductor material so that the content of material P-1 was 1.0 mass % relative to the total mass of the ink composition.

[0387] [Filterability test of ink composition] The filterability test was carried out in the same manner as in Example 1.

[0388] As a result, the ink composition I-8 was able to pass through the PTFE filter without clogging it, and the filtration was completed. Therefore, the filterability was evaluated as good (○). The results are also shown in Table 4 below. [Table 4]

[0389] <Example 8 and Comparative Example 2> Ink compositions (I-9) and (I-10) were prepared in the same manner as in Example 1, except that material P-1 having the z-average molecular weight (Mz) and weight-average molecular weight (Mw) shown in Table 3 below was used as a p-type semiconductor material, and material P-1 was 1% by mass relative to the total mass of the ink composition, and material N-2 was used as an n-type semiconductor material, and material N-2 was 0.3% by mass relative to the total mass of the ink composition, and mixed using a mixed solvent of o-xylene (97% by mass) and acetophenone (3% by mass) as a solvent, and a filterability test was performed. The results are shown in Table 5 below.

[0390] [Table 5]

[0391] <Example 9 and Comparative Example 3> Inks (I-11) and (I-12) were prepared in the same manner as in Example 1, except that material P-1 having the z-average molecular weight (Mz) and weight-average molecular weight (Mw) shown in Table 4 below was used as the p-type semiconductor material, and material P-1 was mixed at 1.0 mass% relative to the total mass of the ink composition, and material N-3 was used as the n-type semiconductor material, and material N-3 was mixed at 1.0 mass% relative to the total mass of the ink composition using o-dichlorobenzene as a solvent, and a filterability test was performed. The results are shown in Table 6 below.

[0392] [Table 6]

[0393] <Example 10 and Comparative Example 4> Ink compositions (I-13) and (I-14) were prepared and subjected to a filterability test in the same manner as in Example 1, except that material P-2 having the z-average molecular weight (Mz) and weight-average molecular weight (Mw) shown in Table 4 below was used as the p-type semiconductor material and material P-2 was mixed in an amount of 0.8 mass% relative to the total mass of the ink composition. The results are shown in Table 7 below.

[0394] [Table 7]

[0395] As is apparent from the above examples and comparative examples, it has been found that the filterability of the ink composition cannot be controlled by the weight average molecular weight (Mw), and no correlation is observed with the type, solvent, or concentration of the n-type semiconductor material used in the ink composition. However, it can be improved without trial and error and without clogging the filter by setting the z-average molecular weight (Mz) of the p-type semiconductor material within the above-mentioned specified range.

[0396] <Example 11> [Production and evaluation of photoelectric conversion elements] (1) Manufacturing of photoelectric conversion elements (Cathode formation) A glass substrate on which an ITO film was formed to a thickness of 100 nm by sputtering was prepared (hereinafter, a laminate including a glass substrate in the middle of manufacture will simply be referred to as a glass substrate). The glass substrate was subjected to a cleaning treatment using an ozone UV treatment to form a cathode.

[0397] (Formation of Electron Transport Layer) Next, the cleaned glass substrate was immersed for 5 minutes in a solution of 80% ethoxylated polyethyleneimine aqueous solution (Sigma-Aldrich, 37% by weight aqueous solution) dissolved in water to a concentration of 0.1% by weight. After the glass substrate was removed, it was placed on a hot plate and the coating was dried in air at 100°C for 10 minutes.

[0398] The dried glass substrate was washed with water, and the washed glass substrate was placed on a hot plate to dry the coating film on the cathode in air at 100° C. for 10 minutes, thereby forming the coating film into an electron transport layer.

[0399] (Formation of active layer) Next, the ink composition (I-1) according to Example 1 was applied onto the electron transport layer by a slot die coating method to form a coating film, and then vacuum drying treatment (pressure 10 Pa, 70°C) was performed for 5 minutes to form the coating film as an active layer. The glass substrate on which the active layer was formed was placed on a hot plate, and the active layer was dried at 100°C for 12 minutes. The thickness of the active layer after drying was 200 nm.

[0400] (Formation of the anode) Next, a suspension of poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid dissolved in water (Clevios F HC Solar, manufactured by Heraeus) was applied onto the active layer by spin coating to form a coating film. The glass substrate on which the coating film was formed was placed in an oven, and the coating film was dried at 85° C. for 30 minutes to form an anode. The thickness of the anode after drying was about 120 nm. Through the above steps, the photoelectric conversion element according to Example 11 was manufactured.

[0401] [Evaluation of photoelectric conversion elements] (External quantum efficiency (EQE) evaluation) With a reverse bias voltage of 2 V applied to the photoelectric conversion element manufactured as described above, a monochromatic light of 800 nm (photon count: 5 × 10) was applied using a spectral sensitivity measurement device (manufactured by Bunkoukeiki Co., Ltd., product name: CEP-2000 type). 14 The photoelectric conversion element was irradiated with light, the generated current value was measured, and the EQE was calculated by a known method. The results are shown in Table 8.

[0402] <Examples 12 to 14> A photoelectric conversion element was produced and the EQE was determined in the same manner as in Example 11, except that the ink composition I-2 was used as the material for the active layer. The results are shown in Table 8.

[0403] [Table 8]

[0404] As shown in Table 8, it was confirmed that the photoelectric conversion elements using the ink compositions I-1 and I-2 as the material for the active layer functioned without any problems. 4 It was confirmed that the photoelectric conversion elements using the ink compositions I-3 and I-4, which have a larger EQE than 100%, as materials for the active layer had a higher EQE. [Explanation of symbols]

[0405] 1 Image detection section 2 Display device 10 Photoelectric conversion element 11, 210 Support substrate 12 First electrode 13 Electron transport layer 14 Active layer 15 Hole transport layer 16 Second electrode 17 Sealing member 20 CMOS transistor substrate 30 Interlayer insulating film 32 Interlayer wiring section 40 Sealing layer 42 Scintillator 44 Reflective layer 46 Protective layer 50 Color Filters 100 Fingerprint detection unit 200 Display panel section 200a display area 220 Organic EL element 230 Touch Sensor Panel 240 Sealing substrate 300 Vein detection unit 302 Glass substrate 304 Light source section 306 Cover part 310 Insertion part 400 Image detector for TOF distance measuring device 402 Floating Diffusion Layer 404 Photogate 406 Shading part

Claims

1. A preparation step of preparing multiple types of polymer compounds that are p-type semiconductor materials; a selection step of selecting a polymer compound having a z-average molecular weight of less than 5.0×10 5 as a p-type semiconductor material from the polymer compounds prepared in the preparation step; a step of mixing the p-type semiconductor material and the n-type semiconductor material selected in the selection step with a solvent to produce an ink composition; A method for producing an ink composition for use in producing a photoelectric conversion element, comprising:

2. The p-type semiconductor material has a weight average molecular weight of 6.0×10 ４ The method for producing an ink composition for use in producing a photoelectric conversion element according to claim 1 , further comprising a polymer compound having a size larger than 100 nm.

3. The method for producing an ink composition for producing a photoelectric conversion element according to claim 1 or 2, wherein the p-type semiconductor material comprises a polymer compound including a structural unit having a thiophene skeleton.

4. The method for producing an ink composition for producing a photoelectric conversion element according to claim 3 , wherein the p-type semiconductor material includes a polymer compound having a donor-acceptor structure.

5. The method for producing an ink composition for use in producing a photoelectric conversion element according to any one of claims 1 to 4, wherein the solvent contains an aromatic hydrocarbon.

6. The method for producing an ink composition for producing a photoelectric conversion element according to any one of claims 1 to 5, wherein the n-type semiconductor material contains a fullerene derivative.

7. The method for producing an ink composition for producing a photoelectric conversion element according to any one of claims 1 to 5, wherein the n-type semiconductor material contains a non-fullerene compound.

8. A method for producing an ink composition for producing a photoelectric conversion element according to claim 1, comprising a step of filtering the ink composition through a filter having a pore size of 0.5 μm or less.

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