CN117242913A - Ink composition and method for producing same - Google Patents

Ink composition and method for producing same Download PDF

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Publication number
CN117242913A
CN117242913A CN202280029664.3A CN202280029664A CN117242913A CN 117242913 A CN117242913 A CN 117242913A CN 202280029664 A CN202280029664 A CN 202280029664A CN 117242913 A CN117242913 A CN 117242913A
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group
ink composition
type semiconductor
photoelectric conversion
substituent
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横井优季
片仓史郎
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Sumitomo Chemical Co Ltd
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Sumitomo Chemical Co Ltd
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K39/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic radiation-sensitive element covered by group H10K30/00
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/50—Photovoltaic [PV] devices
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/549—Organic PV cells

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Organic Chemistry (AREA)
  • Inks, Pencil-Leads, Or Crayons (AREA)
  • Solid State Image Pick-Up Elements (AREA)
  • Photovoltaic Devices (AREA)
  • Light Receiving Elements (AREA)

Abstract

The present invention provides an ink composition which does not require trial and error, can be filtered more reliably without clogging a filter in a manufacturing process, is less likely to cause electrical defects such as insulation and short circuits, and further provides a method for manufacturing an ink composition which can further improve the manufacturing efficiency of the ink composition and even the manufacturing efficiency of a photoelectric conversion element. The present invention is an ink composition for manufacturing a photoelectric conversion element, which is an ink composition comprising a p-type semiconductor material, an n-type semiconductor material, and a solvent, the p-type semiconductor material comprising a z-average molecular weight of less than 5.0X10 5 Is a polymer compound of (a). The p-type semiconductor material preferably comprises a material having a weight average molecular weight greater than 6.0X10 4 Is a polymer compound of (a).

Description

Ink composition and method for producing same
Technical Field
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
The photoelectric conversion element is a very useful device from the viewpoints of, for example, energy saving and reduction of carbon dioxide emission, and has been attracting attention.
In the production of photoelectric conversion elements, for example, optical sensing elements (OPDs), there is known a production method of forming functional layers such as an active layer, an electron transport layer, and a hole transport layer by applying an ink composition for producing the photoelectric conversion elements to a coating object (see non-patent document 1).
Prior art literature
Non-patent literature
Non-patent document 1: strobel 2019Flex.Print.Electron.4 043001
Disclosure of Invention
Problems to be solved by the invention
In a photoelectric conversion element in which an ink composition is used and a functional layer is formed by a coating method, for example, when an active layer of a bulk heterojunction type is formed, a p-type semiconductor material, an n-type semiconductor material, and a solvent are generally contained in the ink composition for forming the active layer. When such an ink composition is mixed with a foreign material, an electrical defect such as insulation or short circuit may occur in an active layer formed using the ink composition. Therefore, in the production of the ink composition, the p-type semiconductor material and the n-type semiconductor material are usually dissolved in a solvent, and then subjected to a filtration treatment using a filter having a predetermined pore size.
However, in the above-described conventional ink composition, depending on the choice of the p-type semiconductor material and/or the n-type semiconductor material, there are cases where the filter is clogged during filtration, and the filtration cannot be performed at all, and thus the photoelectric conversion element cannot be manufactured.
Means for solving the problems
The present inventors have made intensive studies to solve the above problems, and as a result, have found that the components of an ink composition for clogging a filter contain an ultra-high molecular weight component of a p-type semiconductor material. However, the ultra-high molecular weight component is contained in the ink composition in a very small amount, and is extremely difficult to remove from the ink composition produced. Accordingly, the present inventors have found that the above problems can be solved by controlling the content of the ultra-high molecular weight component of the p-type semiconductor material used as a raw material to be not more than a predetermined value and controlling the z-average molecular weight of the p-type semiconductor material contained in the ink composition to be within a predetermined range, and completed the present invention.
Accordingly, the present invention provides the following [1] to [9].
[1]An ink composition for manufacturing a photoelectric conversion element, which is an ink composition comprising a p-type semiconductor material, an n-type semiconductor material, and a solvent, the p-type semiconductor material comprising a z-average molecular weight of less than 5.0X10 5 Is a polymer compound of (a).
[2]According to [1]]The ink composition for manufacturing a photoelectric conversion element, wherein the p-type semiconductor material comprises a material having a weight average molecular weight of more than 6.0X10 4 Is a polymer compound of (a).
[3] The ink composition for manufacturing a photoelectric conversion element according to [1] or [2], wherein the p-type semiconductor material comprises a polymer compound having a structural unit of a thiophene skeleton.
[4] The ink composition for manufacturing 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 manufacturing 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 manufacturing 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, wherein the method for producing an ink composition according to any one of [1] to [7] comprises a step of filtering the ink composition with a filter having a pore diameter of 0.5 μm or less.
[9] A method of manufacturing an ink composition for manufacturing a photoelectric conversion element, comprising:
a preparation step of preparing a plurality of polymer compounds as p-type semiconductor materials;
the polymer compound prepared in the preparation step is selected to have a z-average molecular weight of less than 5.0X10 5 A screening step of using the polymer compound of (a) as a p-type semiconductor material; and
and a step of mixing the p-type semiconductor material, the n-type semiconductor material, and the solvent, which are selected in the step of selecting, to produce an ink composition.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, there can be provided an ink composition which does not require a test error, can be more reliably filtered without clogging a filter in a production process, is less likely to cause electrical defects such as insulation and short-circuiting, and further, a method for producing an ink composition which can further improve the production efficiency of the ink composition and even the production efficiency of a photoelectric conversion element.
Drawings
Fig. 1 is a diagram schematically showing a configuration example of a photoelectric conversion element.
Fig. 2 is a diagram schematically showing a configuration example of the image detection section.
Fig. 3 is a diagram schematically showing a configuration example of the fingerprint detection section.
Fig. 4 is a diagram schematically showing a configuration example of an image detection unit for an X-ray imaging apparatus.
Fig. 5 is a diagram schematically showing a configuration example of a vein detection unit for a vein recognition apparatus.
Fig. 6 is a diagram schematically showing a configuration example of an image detection unit for a TOF type distance measuring device of an indirect type.
Detailed Description
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings only schematically show the shape, size, and arrangement of the constituent elements to the extent that the invention can be understood.
The present invention is not limited to the following description, and each component may be appropriately modified within a range not departing from the gist of the present invention. In the drawings used in the following description, the same reference numerals are given to the same components, and duplicate descriptions may be omitted.
The configuration according to the embodiment of the present invention is not necessarily limited to the configuration illustrated in the drawings.
1. Description of general terms
As used herein, the term "polymer" means a polymer having a molecular weight distribution and a number average molecular weight of 1X 10 in terms of polystyrene 3 Above 1×10 8 The following polymers. The total of the structural units contained in the polymer compound is 100 mol%.
In the present specification, the term "structural unit" means that 1 or more units are present in the polymer compound, and that units are derived from the monomer compound (monomer).
In the present specification, the "hydrogen atom" may be a protium atom or a deuterium atom.
In the present specification, examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The term "having or not having a substituent" includes both cases where all hydrogen atoms constituting a compound or a group are not substituted and cases where some or all of 1 or more hydrogen atoms are substituted with a substituent.
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 alkoxy group, a cycloalkoxy 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 imide group, a substituted oxycarbonyl group, a cyano group, an alkylsulfonyl group, and a nitro group.
In the present specification, "alkyl" may have a substituent. Unless otherwise specified, "alkyl" may be any of straight-chain, branched-chain, and cyclic. The number of carbon atoms of the linear alkyl group is usually 1 to 50, preferably 1 to 30, more preferably 1 to 20, in terms of the number of carbon atoms excluding substituents. The number of carbon atoms of the branched or cyclic alkyl group is usually 3 to 50, preferably 3 to 30, more preferably 4 to 20, in terms of the number of carbon atoms excluding substituents.
Specific examples of the alkyl group include unsubstituted alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, 2-ethylbutyl, n-hexyl, cyclohexyl, n-heptyl, cyclohexylmethyl, cyclohexylethyl, n-octyl, 2-ethylhexyl, 3-n-propylheptyl, adamantyl, n-decyl, 3, 7-dimethyloctyl, 2-ethyloctyl, 2-n-hexyldecyl, n-dodecyl, tetradecyl, hexadecyl, octadecyl, and eicosyl; substituted alkyl groups such as trifluoromethyl, pentafluoroethyl, perfluorobutyl, perfluorohexyl, perfluorooctyl, 3-phenylpropyl, 3- (4-methylphenyl) propyl, 3- (3, 5-di-n-hexylphenyl) propyl, and 6-ethoxyhexyl.
"cycloalkyl" may be a monocyclic group or a polycyclic group. Cycloalkyl groups may have substituents. The number of carbon atoms of the cycloalkyl group is usually 3 to 30, preferably 3 to 20, in terms of the number of carbon atoms excluding substituents.
Examples of cycloalkyl groups include alkyl groups having no substituent such as cyclopentyl, cyclohexyl, cycloheptyl, and adamantyl groups, and groups in which a hydrogen atom is substituted with a substituent such as an alkyl group, an alkoxy group, an aryl group, and a fluorine atom.
Specific examples of the cycloalkyl group having a substituent include methylcyclohexyl and ethylcyclohexyl.
"alkenyl" may be straight-chain or branched. Alkenyl groups may have substituents. The number of carbon atoms of the alkenyl group is usually 2 to 30, preferably 2 to 20, in terms of the number of carbon atoms excluding substituents.
Examples of the alkenyl group include alkenyl groups having no substituent such as vinyl group, 1-propenyl group, 2-butenyl group, 3-pentenyl group, 4-pentenyl group, 1-hexenyl group, 5-hexenyl group, and 7-octenyl group, and groups in which a hydrogen atom in these groups is substituted with a substituent such as alkoxy group, aryl group, and fluorine atom.
"cycloalkenyl" 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, in terms of the number of carbon atoms excluding substituents.
Examples of the cycloalkenyl group include a cycloalkenyl group having no substituent such as a cyclohexenyl group, and a group in which a hydrogen atom in these groups is substituted with a substituent such as an alkyl group, an alkoxy group, an aryl group, or a fluorine atom.
Examples of the cycloalkenyl group having a substituent include methylcyclohexenyl and ethylcyclohexenyl.
"alkynyl" may be straight-chain or branched. Alkynyl groups may have substituents. The number of carbon atoms of the alkynyl group is usually 2 to 30, preferably 2 to 20, in terms of the number of carbon atoms excluding substituents.
Examples of the alkynyl group include an unsubstituted alkynyl group such as an ethynyl group, 1-propynyl group, 2-butynyl group, 3-pentynyl group, 4-pentynyl group, 1-hexynyl group, 5-hexynyl group, and a group in which a hydrogen atom is substituted with a substituent such as an alkoxy group, an aryl group, or a fluorine atom.
"cycloalkynyl" may be a monocyclic group or a polycyclic group. The cycloalkynyl group may have a substituent. The number of carbon atoms of the cycloalkynyl group is usually 4 to 30, preferably 4 to 20, in terms of the number of carbon atoms excluding substituents.
Examples of the cycloalkynyl group include a cycloalkynyl group having no substituent such as a cyclohexenyl group, and a group in which a hydrogen atom in these groups is substituted with a substituent such as an alkyl group, an alkoxy group, an aryl group, or a fluorine atom.
Examples of the substituted cycloalkynyl group include methylcyclohexynyl group and ethylcyclohexynyl group.
The "alkoxy group" may be linear or branched. The alkoxy group may have a substituent. The number of carbon atoms of the alkoxy group is usually 1 to 30, preferably 1 to 20, in terms of the number of carbon atoms excluding substituents.
Examples of the alkoxy group include an unsubstituted alkoxy group such as a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, an isobutoxy group, a tert-butoxy group, a n-pentyloxy group, a n-hexyloxy group, a n-heptyloxy group, a n-octyloxy group, a 2-ethylhexyloxy group, a n-nonyloxy group, a n-decyloxy group, a 3, 7-dimethyloctyloxy group, a 3-heptyldodecyloxy group, a lauryloxy group and the like, and a group in which a hydrogen atom is substituted with a substituent such as an alkoxy group, an aryl group and a fluorine atom.
The cycloalkyl group of the "cycloalkoxy group" may be a monocyclic group or a polycyclic group. The cycloalkoxy group may have a substituent. The number of carbon atoms of the cycloalkoxy group is usually 3 to 30, preferably 3 to 20, in terms of the number of carbon atoms excluding substituents.
Examples of the cycloalkoxy group include a cycloalkoxy group having no substituent such as a cyclopentyloxy group, a cyclohexyloxy group, and a cycloheptyloxy group, and a group in which a hydrogen atom in these groups is substituted with a substituent such as a fluorine atom or an alkyl group.
"alkylthio" may be straight-chain or branched. Alkylthio groups may have substituents. The number of carbon atoms of the alkylthio group is usually 1 to 30, preferably 1 to 20, in terms of the number of carbon atoms excluding substituents.
Examples of the alkylthio group which may have a substituent(s) include a methylthio group, an ethylthio group, a n-propylthio group, an isopropylthio group, a n-butylthio group, an isobutylthio group, a tert-butylthio group, a n-pentylthio group, a n-hexylthio group, a n-heptylthio group, a n-octylthio group, a 2-ethylhexylthio group, a n-nonylthio group, a n-decylthio group, a 3, 7-dimethyloctylthio group, a 3-heptyldodecylthio group, a laurylthio group and a trifluoromethylthio group.
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, in terms of the number of carbon atoms excluding substituents.
Examples of the cycloalkylthio group which may have a substituent include cyclohexylthio.
"p-valent aromatic carbocyclyl" refers to an atomic group that remains by removing p hydrogen atoms directly bonded to carbon atoms constituting a ring from an aromatic hydrocarbon that may have a substituent. The p-valent aromatic carbocyclyl group may further have a substituent.
"aryl" refers to a monovalent aromatic carbocyclyl group. The aryl group may have a substituent. The number of carbon atoms of the aryl group is usually 6 to 60, preferably 6 to 48, in terms of the number of carbon atoms excluding substituents.
Examples of the aryl group include aryl groups having no substituent such as phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-fluorenyl group, 3-fluorenyl group, 4-fluorenyl group, 2-phenylphenyl group, 3-phenylphenyl group, 4-phenylphenyl group and the like, and groups in which a hydrogen atom is substituted with a substituent such as alkyl group, alkoxy group, aryl group, fluorine atom and the like.
"aryloxy" may have a substituent. The number of carbon atoms of the aryloxy group is usually 6 to 60, preferably 6 to 48, in terms of the number of carbon atoms excluding substituents.
Examples of the aryloxy group include an unsubstituted aryloxy group such as a phenoxy group, a 1-naphthoxy group, a 2-naphthoxy group, a 1-anthracenoxy group, a 9-anthracenoxy group, and a 1-pyrenyloxy group, and a group in which a hydrogen atom in these groups is substituted with a substituent such as an alkyl group, an alkoxy group, and a fluorine atom.
The "arylthio group" may have a substituent. The number of carbon atoms of the arylthio group is usually 6 to 60, preferably 6 to 48, in terms of the number of carbon atoms excluding substituents.
Examples of the arylthio group which may have a substituent(s) include a phenylthio group, a C1-C12 alkoxyphenylthio group, a C1-C12 alkylphenylthio group, a 1-naphthylthio group, a 2-naphthylthio group and a pentafluorophenylthio group. "C1-C12" means that the number of carbon atoms of the group described immediately after is 1-12. Further, "Cm to Cn" means that the number of carbon atoms of the group described immediately after is m to n. The following is the same.
The "p-valent heterocyclic group" (p represents an integer of 1 or more) means a group in which p hydrogen atoms out of hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting a ring are removed from a heterocyclic compound which may have a substituent. The "p-valent heterocyclic group" includes "p-valent aromatic heterocyclic group". The "p-valent aromatic heterocyclic group" refers to an atomic group which is left by removing p hydrogen atoms out of hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting a ring from an aromatic heterocyclic compound which may have a substituent.
The aromatic heterocyclic compound includes a compound having an aromatic ring fused to a heterocyclic ring, in addition to a compound having an aromatic property of the heterocyclic ring itself, although the heterocyclic ring itself does not have an aromatic property.
Specific examples of the aromatic heterocyclic compound include oxadiazole, thiadiazole, thiazole, oxazole, thiophene, pyrrole, phosphole, furan, pyridine, pyrazine, pyrimidine, triazine, pyridazine, quinoline, isoquinoline, carbazole, and dibenzophosphole, which are compounds having an aromatic nature in the heterocyclic ring itself.
Specific examples of the aromatic heterocyclic compound include phenoxazine, phenothiazine, dibenzoborole, silafluorene (dibenzosilole), and benzopyran, which are compounds in which the heterocyclic ring itself does not exhibit aromatic properties and an aromatic ring is condensed on the heterocyclic ring.
The p-valent heterocyclic group may have a substituent. The number of carbon atoms of the p-valent heterocyclic group is usually 2 to 60, preferably 2 to 20, in terms of the number of carbon atoms excluding substituents.
Examples of the monovalent heterocyclic group include monovalent aromatic heterocyclic groups (for example, thienyl, pyrrolyl, furyl, pyridyl, quinolinyl, isoquinolinyl, pyrimidinyl, triazinyl), monovalent non-aromatic heterocyclic groups (for example, piperidyl, piperazinyl), and groups in which a hydrogen atom is substituted with a substituent such as an alkyl group, an alkoxy group, or a fluorine atom.
"substituted amino" 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 in terms of the number of carbon atoms excluding the substituent.
Examples of the substituted amino group include a dialkylamino group (for example, a dimethylamino group, a diethylamino group), a diarylamino group (for example, a diphenylamino group, a bis (4-methylphenyl) amino group, a bis (4-tert-butylphenyl) amino group, and a bis (3, 5-di-tert-butylphenyl) amino group).
The "acyl group" may have a substituent. The number of carbon atoms of the acyl group is usually 2 to 20, preferably 2 to 18, in terms of the number of carbon atoms excluding substituents. Specific examples of the acyl group include acetyl, propionyl, butyryl, isobutyryl, pivaloyl, benzoyl, trifluoroacetyl and pentafluorobenzoyl.
The "imine residue" refers to an atomic group remaining after 1 hydrogen atom directly bonded to a carbon atom or a nitrogen atom constituting a carbon atom-nitrogen atom double bond is removed from an imine compound. "imine compound" refers to an organic compound having a carbon atom-nitrogen atom double bond within the molecule. Examples of the imine compound include aldimines, ketimines, and compounds in which a hydrogen atom bonded to a nitrogen atom constituting a carbon atom-nitrogen atom double bond in aldimines is substituted with a substituent such as an alkyl group.
The number of carbon atoms of the imine residue is usually 2 to 20, preferably 2 to 18. Examples of the imine residue include groups represented by the following structural formulae.
[ chemical formula 1]
"amide group" refers to a radical remaining from an amide by removing 1 hydrogen atom bonded to a nitrogen atom. The number of carbon atoms of the amide group is usually about 1 to 20, preferably 1 to 18. Specific examples of the amide group include a carboxamide group, an acetamido group, a propionamide group, a butyrylamino group, a benzamide group, a trifluoroacetamido group, a pentafluorobenzamide group, a dicarboxamide group, a diacetylamino group, a dipropionamide group, a dibutylamino group, a dibenzoylamino group, a bis (trifluoroacetamide) group and a bis (pentafluorobenzamide) group.
"imide group" refers to an atomic group that remains after 1 hydrogen atom bonded to a nitrogen atom is removed from an imide. The number of carbon atoms of the imide group is usually 4 to 20. Specific examples of the imide group include the following groups.
[ chemical formula 2]
"substituted oxycarbonyl" refers to a group represented by R' -O- (c=o) -.
Here, R' represents an alkyl group, an aryl group, an arylalkyl group, or a monovalent heterocyclic group.
The number of carbon atoms of the substituted oxycarbonyl group is usually 2 to 60, preferably 2 to 48.
Specific examples of the substituted oxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, butoxycarbonyl group, isobutoxycarbonyl group, tert-butoxycarbonyl group, pentoxycarbonyl group, hexyloxycarbonyl group, cyclohexyloxycarbonyl group, heptoxycarbonyl group, octoxycarbonyl group, 2-ethylhexyloxycarbonyl group, nonyloxycarbonyl group, decyloxycarbonyl group, 3, 7-dimethyloctoxycarbonyl group, dodecyloxycarbonyl group, trifluoromethoxycarbonyl group, pentafluoroethoxycarbonyl group, perfluorobutoxycarbonyl group, perfluorohexoxycarbonyl group, perfluorooctoxycarbonyl group, phenoxycarbonyl group, naphthyloxycarbonyl group and pyridyloxycarbonyl group.
The "alkylsulfonyl" may be linear or branched. The alkylsulfonyl group may have a substituent. The number of carbon atoms of the alkylsulfonyl group is usually 1 to 30 in terms of the number of carbon atoms excluding substituents. Specific examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group and a dodecylsulfonyl group.
The chemical formula labeled "×" indicates a bond.
"pi conjugated system" refers to a system in which pi electrons cross over multiple bonds to undergo delocalization.
"(meth) acrylic" includes acrylic acid, methacrylic acid, and combinations thereof.
In the present specification, the term "ink composition" refers to a liquid composition used in a coating method, and is not limited to a colored liquid. The "coating method" refers to a method of forming a film using a liquid substance typified by an ink composition.
The "ink composition" may be a solution, or a dispersion such as a dispersion, emulsion (emulsion), suspension (suspension), or the like.
2. Ink composition
The ink composition of the present embodiment is an ink composition for producing a photoelectric conversion element, which contains a p-type semiconductor material, an n-type semiconductor material, and a solvent, wherein the p-type semiconductor material contains a z-average molecular weight of less than 5.0X10 5 Is a polymer compound of (a).
As described above, the ink composition of the present embodiment is an ink composition for manufacturing a photoelectric conversion element, and is preferably an ink composition for forming an active layer.
Hereinafter, the components that can be contained in the ink composition of the present embodiment will be specifically described.
Here, the p-type semiconductor material comprises at least one electron donating compound, and the n-type semiconductor material comprises at least one electron accepting compound. Which of the semiconductor material contained in the ink composition functions as the p-type semiconductor material and the n-type semiconductor material may be relatively determined according to the HOMO level value or LUMO level value of the selected compound.
The relationship between the energy level values of HOMO and LUMO of the p-type semiconductor material and the energy level values of HOMO and LUMO of the n-type semiconductor material can be appropriately set within a range in which the (cured) film formed of the ink composition exhibits specific functions such as photoelectric conversion function and photodetection function.
(1) P-type semiconductor material
In this embodiment mode, the p-type semiconductor material may be a low-molecular compound or a high-molecular compound.
Examples of the p-type semiconductor material as the low molecular compound include phthalocyanine, metallophthalocyanine, porphyrin, metalloporphyrin, oligothiophene, tetracene, pentacene, and rubrene.
The p-type semiconductor material that the ink composition of the present embodiment may contain preferably contains a pi-conjugated polymer compound (also referred to as a D-a type conjugated polymer compound) having a donor-acceptor structure including a donor structural unit (also referred to as a D structural unit) and an acceptor structural unit (also referred to as a structural unit).
Here, the donor structural unit is a pi electron excess structural unit, and the acceptor structural unit is a pi electron deficiency structural unit.
In this embodiment, the structural unit constituting the p-type semiconductor material includes a structural unit in which a donor structural unit and an acceptor structural unit are directly bonded, and further includes a structural unit in which a donor structural unit and an acceptor structural unit are bonded via any suitable spacer (group or structural unit).
Examples of the p-type semiconductor material of the polymer compound include polyvinylcarbazole and its derivatives, polysilane and its derivatives, polysiloxane derivatives having an aromatic amine structure in a side chain or a main chain, polyaniline and its derivatives, polythiophene and its derivatives, polypyrrole and its derivatives, polyphenylacetylene and its derivatives, polythiophene acetylene and its derivatives, polyfluorene and its derivatives. As the p-type semiconductor material, a polymer compound containing a structural unit having a thiophene skeleton is preferably used.
The p-type semiconductor material is preferably a polymer compound containing a structural unit represented by the following formula (I) and/or a structural unit represented by the following formula (II) from the viewpoint of further improving the stability of the ink composition and further from the viewpoint of further improving the external quantum efficiency of the photoelectric conversion element.
[ chemical formula 3]
In the formula (I), ar 1 Ar 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).
[ chemical formula 4]
-Ar 3 - (II)
In the formula (II), ar3 represents a divalent aromatic heterocyclic group.
[ chemical formula 5]
In the formulae (Z-1) to (Z-7), R represents
A hydrogen atom,
Halogen atom,
An alkyl group which may have a substituent,
Cycloalkyl which may have a substituent,
Alkenyl group which may have substituent(s),
Cycloalkenyl group which may have substituent(s),
Alkynyl group which may have substituent(s),
A cycloalkynyl group which may have a substituent(s),
Aryl which may have a substituent,
Alkoxy which may have a substituent,
A cycloalkoxy group which may have a substituent(s),
Aryloxy group which may have a substituent,
Alkylthio which may have a substituent,
A cycloalkylthio group which may have a substituent(s),
Arylthio which may have a substituent,
Monovalent heterocyclic groups which may have a substituent(s),
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 imide group which may have a substituent,
A substituted oxycarbonyl group which may have a substituent(s),
Cyano group,
Nitro group,
-C(＝O)-R c A group represented by, or
-SO 2 -R d The group(s) represented by (a) is (are),
R c r is R d Each independently represents
A hydrogen atom,
An alkyl group which may have a substituent,
Cycloalkyl which may have a substituent,
Aryl which may have a substituent,
Alkoxy which may have a substituent,
A cycloalkoxy group which may have a substituent(s),
Aryloxy groups which may have substituents, or
Monovalent heterocyclic groups which may have a substituent.
In the formulae (Z-1) to (Z-7), when there are 2R, 2R may be the same or different.
R in the formulae (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 having 1 to 40 carbon atoms, still more preferably a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, particularly preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. These groups may have a substituent. When there are plural R's, the plural R's may be the same or different from each other.
The structural unit represented by the formula (I) is preferably a structural unit represented by the following formula (I-1).
[ chemical formula 6]
In the formula (I-1), Z represents the same meaning as described above.
Examples of the structural unit represented by the formula (I-1) include structural units represented by the following formulas (501) to (505).
[ chemical formula 7]
In the above formulae (501) to (505), R represents the same meaning as described above. When there are 2R, 2R may be the same or different from each other.
In the above formula (II), ar 3 The number of carbon atoms of the divalent aromatic heterocyclic group represented is usually 2 to 60, preferably 4 to 60, more preferably 4 to 20.Ar (Ar) 3 The divalent aromatic heterocyclic group represented may have a substituent. As Ar 3 Examples of the substituent which may be contained in the divalent aromatic heterocyclic group represented by the formula (I) 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 imide group, a substituted oxycarbonyl group, an alkenyl group, an alkynyl group, a cyano group and a nitro group.
As Ar 3 Examples of the divalent aromatic heterocyclic group represented by the formula (101) to (190) below are given.
[ chemical formula 8]
[ chemical formula 9]
[ chemical formula 10]
[ chemical formula 11]
In the formulae (101) to (190), R represents the same meaning as described above. When there are a plurality of R's, the plurality of R's may be the same or different from each other.
As the structural unit represented by the above formula (II), structural units represented by the following formulas (II-1) to (II-6) are preferable.
[ chemical formula 12]
In the formulae (II-1) to (II-6), X 1 X is X 2 Each independently represents an oxygen atom or a sulfur atom, and R represents the same meaning as described above. When there are a plurality of R's, the plurality of R's may be the same or different from each other.
X in the formulae (II-1) to (II-6) from the viewpoint of availability of the starting compounds 1 X is X 2 Sulfur atoms are all preferred.
The polymer compound as the p-type semiconductor material may contain 2 or more structural units of the formula (I) or 2 or more structural units of the formula (II).
From the viewpoint of improving the solubility in a solvent, the polymer compound as the p-type semiconductor material may contain a structural unit represented by the following formula (III).
[ chemical formula 13]
-Ar 4 - (III)
In the formula (III), ar 4 Represents arylene.
Ar 4 The arylene group represented here means an atomic group remaining by removing 2 hydrogen atoms from an aromatic hydrocarbon which may have a substituent. The aromatic hydrocarbon includes a compound having a condensed ring, and a compound in which 2 or more members selected from the group consisting of independent benzene rings and condensed rings are bonded directly or via a divalent group such as a vinylidene group.
Examples of the substituent that may be contained in the aromatic hydrocarbon include the same substituents as those described above as examples of the substituent that may be contained in the heterocyclic compound.
The number of carbon atoms in the portion other than the substituent in the arylene group is usually 6 to 60, preferably 6 to 20. The number of carbon atoms of the arylene group including the substituent is usually 6 to 100.
Examples of the arylene group include a phenylene group (for example, formula 1 to formula 3 below), a naphthalene-diyl group (for example, formula 4 to formula 13 below), an anthracene-diyl group (for example, formula 14 to formula 19 below), a biphenyl-diyl group (for example, formula 20 to formula 25 below), a terphenyl-diyl group (for example, formula 26 to formula 28 below), a condensed ring compound group (for example, formula 29 to formula 35 below), a fluorene-diyl group (for example, formula 36 to formula 38 below), and a benzofluorene-diyl group (for example, formula 39 to formula 46 below).
[ chemical formula 14]
[ chemical formula 15]
[ chemical formula 16]
[ chemical formula 17]
[ chemical formula 18]
[ chemical formula 19]
[ chemical formula 20]
[ chemical formula 21]
In the formulae 1 to 46, R has the same meaning as described above. When there are a plurality of R's, the plurality of R's may be the same or different from each other.
When the polymer compound as the p-type semiconductor material contains the structural unit represented by the formula (I) and/or the structural unit represented by the formula (II), the total amount of the structural unit represented by the formula (I) and the structural unit represented by the formula (II) is usually 20 to 100 mol%, and is preferably 40 to 100 mol%, more preferably 50 to 100 mol%, for the reason of improving the charge transport property as the p-type semiconductor material.
As a suitable specific example of the polymer compound as the P-type semiconductor material, polymer compounds represented by the following formulas P-1 to P-10 can be given.
[ chemical formula 22]
[ chemical formula 23]
[ chemical formula 24]
[ chemical formula 25]
In the ink composition of the present embodiment, the p-type semiconductor material includes a material having a z-average molecular weight of less than 5.0X10 5 Is a polymer compound of (a).
The present embodiment relates toIn the ink composition, more specifically, the p-type semiconductor material preferably contains a material having a weight average molecular weight of more than 6.0X10 from the viewpoint of improving the photoelectric conversion efficiency, for example, from the viewpoint of preferably setting the External Quantum Efficiency (EQE) to 50% or more 4 From the viewpoint of both photoelectric conversion efficiency and filterability, the polymer compound of (2) preferably contains a polymer having a z-average molecular weight of less than 5.0X10 5 And a weight average molecular weight greater than 6.0X10 4 Is a polymer compound of (a).
In the ink composition of the present embodiment, the z-average molecular weight (Mz) of the p-type semiconductor material is preferably greater than 1.5x10 from the viewpoint of preferably having an external quantum efficiency of 50% or more 5 。
In the ink composition of the present embodiment, the weight average molecular weight of the polymer compound as the p-type semiconductor material is usually 1×10 3 ～5×10 5 From the viewpoint of improving the solubility in a solvent, it is preferably 1×10 3 ～3×10 5 。
In the present embodiment, the z-average molecular weight (Mz) and the weight-average molecular weight (Mw) are average molecular weights in terms of polystyrene, which can be measured by Gel Permeation Chromatography (GPC) using any suitable device known in the art.
The ink composition of the present embodiment may contain only 1 compound (polymer compound) as a p-type semiconductor material, or may contain any combination of 2 or more.
Here, the z-average molecular weight (Mz) is a weighted average molecular weight obtained by using the square of the molecular weight as a weight, and is a parameter that tends to be more susceptible to the presence of a high molecular weight molecule than the weight average molecular weight (Mw).
In the present embodiment, the z-average molecular weight (Mz) of the p-type semiconductor material as the polymer compound can be adjusted to be within the above-described suitable range by setting the conditions in the synthesis step of the polymer compound to predetermined conditions.
Specifically, for example, in the above-described synthesis step of the polymer compound, the z-average molecular weight (Mz) can be adjusted to be within the appropriate range by appropriately adjusting the feed compositions (mixing ratios) of the plurality of monomers to be raw materials, appropriately adjusting the amount of the catalyst to be used, and appropriately adjusting the concentration of the reaction solution. More specifically, for example, the z-average molecular weight (Mz) may be appropriately adjusted with reference to "a bulk polymer", an overview described in 2009, 30, 261, or the like.
According to the ink composition of the present embodiment using the p-type semiconductor material having the z-average molecular weight (Mz) as described above, a trial and error is not required, and the filter can be more reliably filtered without clogging the filter in the manufacturing process, and electrical defects such as insulation and short-circuiting are less likely to occur, so that the manufacturing efficiency of the ink composition and even the manufacturing efficiency of the photoelectric conversion element can be further improved.
(2) n-type semiconductor material
The n-type semiconductor material that the ink composition of the present embodiment may contain may be a low-molecular compound or a high-molecular compound.
Examples of the n-type semiconductor material (electron accepting compound) as the low molecular compound include oxadiazole derivatives, anthraquinone dimethane and derivatives thereof, benzoquinone and derivatives thereof, naphthoquinone and derivatives thereof, anthraquinone and derivatives thereof, tetracyanoanthraquinone dimethane and derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof, and C 60 Fullerene such as fullerene, fullerene derivative (hereinafter, may be referred to as fullerene compound) as a derivative thereof, and phenanthrene derivative such as bathocuproine.
Examples of the n-type semiconductor material of the polymer compound include polyvinylcarbazole and its derivatives, polysilane and its derivatives, polysiloxane derivatives having an aromatic amine structure in a side chain or a main chain, polyaniline and its derivatives, polythiophene and its derivatives, polypyrrole and its derivatives, polyphenylacetylene and its derivatives, polythiophene acetylene and its derivatives, polyquinoline and its derivatives, polyquinoxaline and its derivatives, and polyfluorene and its derivatives.
The n-type semiconductor material is preferably 1 or more selected from the group consisting of fullerenes and fullerene derivatives, and more preferably a fullerene derivative.
Examples of fullerenes include C 60 Fullerene, C 70 Fullerene, C 76 Fullerene, C 78 Fullerene and C 84 And (3) fullerene. Examples of the fullerene derivatives include those of fullerene. The fullerene derivative is a compound in which at least a part of fullerene is modified.
Examples of the fullerene derivative include compounds represented by the following formula.
[ chemical formula 26]
In the method, in the process of the invention,
R a represents an alkyl group, an aryl group, a monovalent heterocyclic group, or a group having an ester structure. Multiple R' s a May be the same or different from each other.
R b Represents an alkyl group or an aryl group. Multiple R' s b May be the same or different from each other.
As R a Examples of the group having an ester structure represented by the following formula are given.
[ chemical formula 27]
Wherein u1 represents an integer of 1 to 6. u2 represents an integer of 0 to 6. R is R e Represents an alkyl group, an aryl group or a monovalent heterocyclic group.
As C 60 Examples of fullerene derivatives include the following compounds.
[ chemical formula 28]
As C 70 Examples of fullerene derivatives include the following compounds.
[ chemical formula 29]
Specific examples of the fullerene derivative include methyl [6,6] -Phenyl-C61 butyrate (C60 PCBM), methyl [6,6] -Phenyl-C61 butyrate ([ 6,6] -Phenyl C61 butyric acid methyl ester)), [6,6] -Phenyl-C71 butyrate (C70 PCBM), methyl [6,6] -Phenyl-C71 butyrate ([ 6,6] -Phenyl C71 butyric acid methyl ester)), [6,6] -Phenyl-C85 butyrate (C84 PCBM), methyl [6,6] -Phenyl C85 butyrate ([ 6,6] -Phenyl C85 butyric acid methyl ester)), and methyl [6,6] -Thienyl-C61 butyrate ([ 6,6] -Thienyl C61 butyrate ([ 6,6] -thonyl C61 butyric acid methyl ester)).
The n-type semiconductor material that may be included in the ink composition of the present embodiment includes a compound other than a fullerene compound. In the present specification, an n-type semiconductor material other than a fullerene compound is referred to as a "non-fullerene compound". As the non-fullerene compound, various compounds are known, and any conventionally known suitable non-fullerene compound may be used as the n-type semiconductor material in the present embodiment.
The ink composition of the present embodiment may contain only 1 kind of compound as an n-type semiconductor material, or may contain a plurality of kinds.
In the present embodiment, the non-fullerene compound as the n-type semiconductor material is preferably a compound containing a perylene tetracarboxylic diimide structure. Examples of the non-fullerene compound containing a perylene tetracarboxylic diimide structure include compounds represented by the following formula.
[ chemical formula 30]
[ chemical formula 31]
[ chemical formula 32]
[ chemical formula 33]
Wherein R is as defined above. The plurality of R's may be the same or different from each other.
In this embodiment mode, 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.
[ chemical formula 34]
In the above formula (V), R 1 Represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkoxy group which may have a substituent, a cycloalkoxy group which may have a substituent, an aryl group which may have a substituent, or a monovalent aromatic heterocyclic group which may have a substituent. Multiple R' s 1 May be the same or different from each other.
Preferably a plurality of R 1 Each independently is an alkyl group which may have a substituent.
R 2 Represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkoxy group which may have a substituent, a cycloalkoxy group which may have a substituent, an aryl group which may have a substituent, orA monovalent aromatic heterocyclic group which may have a substituent. Multiple R' s 2 May be the same or different.
Preferable examples of the compound represented by the formula (V) include compounds represented by the following formulas.
[ chemical formula 35]
In this embodiment, the n-type semiconductor material preferably includes a compound represented by the following formula (VI).
A 1 -B 10 -A 2 (VI)
In the formula (VI) of the present invention,
A 1 a is a 2 Each independently represents an electron withdrawing group, B 10 Represents a group comprising a pi conjugated system.
Regarding A as 1 A is a 2 Examples of electron withdrawing groups of (C) include-CH=C (-CN) 2 A group represented by the following formula (a-1) to formula (a-9).
[ chemical formula 36]
In the formulae (a-1) to (a-7),
t represents a carbocycle which may have a substituent, or a heterocycle which may have a substituent. Carbocycles and heterocycles may be monocyclic or condensed rings. When these rings have a plurality of substituents, the plurality of substituents may be the same or different.
Examples of the carbocycle which may have a substituent as T include aromatic carbocycles.
Regarding the carbocycle which may have a substituent as T, an aromatic carbocycle is preferable. Specific examples of the carbocycle which may have a substituent(s) as T include a benzene ring, a naphthalene ring, an anthracene ring, a tetracene ring, a pentacene ring, a pyrene ring and a phenanthrene ring, and are preferably a benzene ring, a naphthalene ring and a phenanthrene ring, more preferably a benzene ring and a naphthalene ring, and still more preferably a benzene ring. These rings may have a substituent.
Examples of the heterocyclic ring which may have a substituent(s) as T include aromatic heterocyclic rings, and aromatic heterocyclic rings are preferred. Specific examples of the heterocyclic ring which may have a substituent(s) as T include a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, an oxazole ring, a thiazole ring and a thienothiophene ring, and preferably a thiophene ring, a pyridine ring, a pyrazine ring, a thiazole ring and a thienothiophene ring, and more preferably a thiophene ring. These rings may have a substituent.
Examples of the substituent that may be contained in the carbocycle or heterocycle as T include a halogen atom, an alkyl group, an alkoxy group, an aryl group, and a monovalent heterocyclic group, and a fluorine atom and/or an alkyl group having 1 to 6 carbon atoms are preferable.
X 4 、X 5 X is X 6 Each independently represents an oxygen atom, a sulfur atom, an alkylidene group or=c (-CN) 2 The radicals represented are preferably oxygen atoms, sulfur atoms or =c (-CN) 2 A group represented by the formula (I).
X 7 Represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent, or a monovalent heterocyclic group.
R a1 、R a2 、R a3 、R a4 R is R a5 Each independently represents a hydrogen atom, an alkyl group which may have a substituent, a halogen atom, an alkoxy group which may have a substituent, an aryl group which may have a substituent, or a monovalent heterocyclic group, and is preferably an alkyl group which may have a substituent or an aryl group which may have a substituent.
[ chemical formula 37]
In the formula (a-8) and the formula (a-9), R a6 R is R a7 Each independently represents a hydrogen atom, a halogen atom, and may have substitutionAlkyl group of a group, cycloalkyl group which may have a substituent, alkoxy group which may have a substituent, cycloalkoxy group which may have a substituent, monovalent aromatic carbocyclic group which may have a substituent, or monovalent aromatic heterocyclic group which may have a substituent, a plurality of R a6 R is R a7 May be the same or different.
Regarding A as 1 A is a 2 The electron withdrawing group of (a) is preferably a group represented by any one of the following formulas (a-1-1) to (a-1-4) and (a-6-1) and (a-7-1), more preferably a group represented by formula (a-1-1). Here, a plurality of R a10 Each independently represents a hydrogen atom or a substituent, preferably represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group which may have a substituent. R is R a3 、R a4 R is R a5 Each independently is 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.
[ chemical formula 38]
Regarding B as 10 Examples of the group containing a pi-conjugated system include- (S) in the compound represented by the following formula (VII) 1 ) n1 -B 11 -(S 2 ) n2 -a group represented.
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)
In the formula (VII), A 1 A is a 2 Each independently represents an electron withdrawing group. A is that 1 A is a 2 Examples and preferred examples of (A) and A in the above formula (VI) 1 A is a 2 The examples and preferred examples described in the above are the same.
S 1 S and S 2 Each independently represents a divalent carbocyclyl group which may have a substituent, or a two group which may have a substituentValence heterocyclic group, -C (R) s1 )＝C(R s2 ) A group represented (here, R s1 R is R s2 Each independently represents a hydrogen atom, a substituent (preferably, a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent), or a group represented by-C≡C-.
S 1 S and S 2 The divalent carbocyclic group which may have a substituent and the divalent heterocyclic group which may have a substituent which are represented may be condensed rings. When the divalent carbocyclyl group or the divalent heterocyclic group has a plurality of substituents, the plurality of substituents may be the same or different.
In the formula (VII), n1 and n2 each independently represent an integer of 0 or more, preferably each independently represent 0 or 1, and more preferably each represents 0 or 1.
Examples of the divalent carbocyclyl group include divalent aromatic carbocyclyl groups.
Examples of the divalent heterocyclic group include divalent aromatic heterocyclic groups.
In the case where the divalent aromatic carbocyclic group or the divalent aromatic heterocyclic group is a condensed ring, all of the rings constituting the condensed ring may be condensed rings having an aromatic property, or only a part of the rings may be condensed rings having an aromatic property.
As S 1 S and S 2 As an example of the above, ar is exemplified 3 Examples of the divalent aromatic heterocyclic group represented by the formula (101) to (190) include groups represented by any one of the formulae, and groups in which a hydrogen atom in the groups is substituted with a substituent.
S 1 S and S 2 Preferably, each independently represents a group represented by the following formula (s-1) or (s-2).
[ chemical formula 39]
In the formula (s-1) and (s-2),
X 3 represents an oxygen atom or a sulfur atom.
R a10 As described aboveAnd (3) the definition is as described.
S 1 S and S 2 The group represented by the formula (142), the formula (148) or the formula (184) or the group in which a hydrogen atom is substituted with a substituent is preferable, and the group represented by the formula (142) or the formula (184) or the group represented by the formula (184) in which 1 hydrogen atom is substituted with an alkoxy group is more preferable.
B 11 A condensed ring group having a structure of 2 or more selected from the group consisting of a carbocyclic ring structure and a heterocyclic ring structure, and represents a condensed ring group which may have a substituent and does not include an o-peri condensed structure.
B 11 The condensed ring group may have a structure in which 2 or more structures identical to each other are condensed.
B 11 When the condensed ring group is represented by a plurality of substituents, the plurality of substituents may be the same or different.
As can be constituted B 11 Examples of the carbocyclic ring structure of the condensed ring group include ring structures represented by the following formula (Cy 1) or formula (Cy 2).
[ chemical formula 40]
As can be constituted B 11 Examples of the heterocyclic structure of the condensed ring group include ring structures represented by any one of the following formulas (Cy 3) to (Cy 10).
[ chemical formula 41]
In the formula (VII), B 11 Preferably, 2 or more condensed ring groups selected from the group consisting of the structures represented by the above formulas (Cy 1) to (Cy 10) do not contain an ortho-peri condensed structure and may have a substituent. B (B) 11 The structure may be one in which 2 or more of the structures represented by the formulae (Cy 1) to (Cy 10) are condensed.
B 11 More preferably, the condensed ring group is a condensed ring group which does not contain an ortho-peri condensed structure and may have a substituent, out of condensed ring groups of 2 or more structures selected from the group consisting of structures represented by the formulae (Cy 1) to (Cy 6) and (Cy 8).
Regarding B as 11 The substituent(s) which the condensed ring group may have is preferably an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. B (B) 11 The aryl group that the condensed ring group represented may have may be substituted with, for example, an alkyl group.
Regarding B as 11 Examples of the condensed ring group of (a) include groups represented by the following formulae (b-1) to (b-14), wherein a hydrogen atom in these groups is substituted with a substituent (preferably an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, or a monovalent heterocyclic group which may have a substituent). Regarding B as 11 The condensed ring group of (a) is preferably a group represented by the following formula (b-2) or (b-3), or a group in which a hydrogen atom in these groups is substituted with a substituent (preferably an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, or a monovalent heterocyclic group which may have a substituent), more preferably a group represented by the following formula (b-2) or (b-3).
[ chemical formula 42]
[ chemical formula 43]
In the formulae (b-1) to (b-14),
R a10 as described above in the definition.
In the formulae (b-1) to (b-14), a plurality of R a10 Each independently is preferably an alkyl group which may have a substituent, or may beWith aryl groups having substituents.
Examples of the compound represented by the formula (VI) or (VII) include compounds represented by the following formulas.
[ chemical formula 44]
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 alkyl group which may have a substituent, an aryl group which may have a substituent, or an alkoxy group which may have a substituent.
The compound represented by the formula (VI) or (VII) may be a compound represented by the following formula.
[ chemical formula 45]
In the ink composition of the present embodiment, the n-type semiconductor material may further include a fullerene and a fullerene derivative (fullerene compound) described above in combination, in addition to the non-fullerene compound described above.
As a suitable specific example of the n-type semiconductor material in this embodiment, a compound represented by the following formula is given.
[ chemical formula 46]
[ chemical formula 47]
[ chemical formula 48]
(3) Solvent(s)
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 particularly preferably a compound capable of dissolving the p-type semiconductor material described above.
Examples of the aromatic hydrocarbon which can be used as the solvent include toluene, xylene (e.g., o-xylene, m-xylene, and p-xylene), trimethylbenzene (e.g., mesitylene, 1,2, 4-trimethylbenzene (pseudocumene)), butylbenzene (e.g., n-butylbenzene, sec-butylbenzene, and t-butylbenzene), methylnaphthalene (e.g., 1-methylnaphthalene), 1,2,3, 4-tetrahydronaphthalene (tetrahydronaphthalene), indane, 1-chloronaphthalene, chlorobenzene, and dichlorobenzene (1, 2-dichlorobenzene).
The solvent may be composed of only 1 aromatic hydrocarbon or 2 or more aromatic hydrocarbons.
The aromatic hydrocarbon constituting the solvent is preferably 1 or more selected from the group consisting of toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2, 4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, t-butylbenzene, methylnaphthalene, tetrahydronaphthalene, 1-chloronaphthalene, chlorobenzene and dichlorobenzene (1, 2-dichlorobenzene), more preferably toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2, 4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, t-butylbenzene, methylnaphthalene, tetrahydronaphthalene, indane, 1-chloronaphthalene, chlorobenzene or dichlorobenzene (o-dichlorobenzene).
The ink composition of the present embodiment may contain a haloalkyl group as a solvent. Examples of the haloalkyl group which can be used as the solvent include chloroform.
The ink composition of the present embodiment preferably contains 1 or more solvents selected from the group consisting of toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2, 4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, t-butylbenzene, methylnaphthalene, tetrahydronaphthalene, indane, 1-chloronaphthalene, chlorobenzene, dichlorobenzene (1, 2-dichlorobenzene), and chloroform.
In the ink composition of the present embodiment, other solvents may be used in combination in addition to the above solvents.
In this embodiment, examples of the other solvents include an aromatic carbonyl compound, an aromatic ester compound, and a nitrogen-containing heterocyclic compound.
Examples of the aromatic carbonyl compound include acetophenone which may have a substituent, propiophenone which may have a substituent, phenylbutanone which may have a substituent, cyclohexylbenzophenone which may have a substituent, and benzophenone which may have a substituent.
Examples of the aromatic ester compound include 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.
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.
The nitrogen-containing heterocyclic compound may have a substituent directly bonded to the ring structure.
Examples of the substituent that may be included in the ring structure (e.g., quinoline ring structure, 1,2,3, 4-tetrahydroquinoline ring structure, quinoxaline ring structure) of the nitrogen-containing heterocyclic compound 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.
Examples of the nitrogen-containing heterocyclic compound having a pyridine ring structure include pyridine which may have a substituent, quinoline which may have a substituent, and isoquinoline which may have a substituent.
Examples of the nitrogen-containing cyclic compound having a pyrazine ring structure include pyrazines which may have substituents and quinoxalines which may have substituents.
Examples of the nitrogen-containing cyclic compound having 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.
Examples of the nitrogen-containing cyclic compound having a pyrimidine ring structure include pyrimidine which may have a substituent, and quinazoline which may have a substituent.
In this embodiment, as a further solvent among the solvents, only 1 kind of aromatic carbonyl compound, aromatic ester compound or nitrogen-containing heterocyclic compound may be further contained, or 2 or more kinds selected from them may be further contained.
In this embodiment, from the viewpoint of environmental protection, a halogen-free solvent is preferably used as the solvent.
(weight ratio of solvent to other solvents)
In the case where the ink composition of the present embodiment contains the above-described solvent and the above-described other solvents, the weight ratio of the solvent to the other solvents (solvent/other solvents) 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.
(weight percent of solvent in ink composition)
The total weight of the solvent contained in the ink composition is preferably 90 mass% or more, more preferably 92 mass% or more, still more preferably 95 mass% or more, in terms of further improving the solubility of the p-type semiconductor material and the n-type semiconductor material, and preferably 99.9 mass% or less, in terms of further improving the concentration of the p-type semiconductor material and the n-type semiconductor material in the ink composition, and in terms of facilitating formation of a layer having a certain thickness or more, when the total weight of the ink composition is set to 100 mass%.
The ink composition may further comprise an optional solvent in addition to the solvents and other solvents described above. When the total weight of all solvents contained in the ink composition is set to 100 wt%, the content of the optional solvent is preferably 10 wt% or less, more preferably 5 wt% or less, and still more preferably 3 wt% or less. As the optional solvent, a solvent having a boiling point higher than that of the other solvents is preferably used.
(concentration of p-type semiconductor material and n-type semiconductor material in ink composition)
The total concentration of the p-type semiconductor material and the n-type semiconductor material in the ink composition may be set to any suitable concentration depending on the thickness of the functional layer (active layer) required, the desired characteristics, and the like. The total concentration of the p-type semiconductor material and the n-type semiconductor material is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, preferably 10 mass% or less, more preferably 5 mass% or less, further preferably 0.01 mass% or more and 20 mass% or less, particularly preferably 0.01 mass% or more and 10 mass% or less, further particularly preferably 0.01 mass% or more and 5 mass% or less, and particularly preferably 0.1 mass% or more and 5 mass% or less.
The p-type semiconductor material and the n-type semiconductor material may be dissolved or dispersed in the ink composition. 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.
(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, further preferably 1/3 or more, preferably 9/1 or less, more preferably 5/1 or less, further preferably 3/1 or less.
3. Method for producing ink composition
The method for producing the ink composition of the present embodiment includes a step of filtering an ink composition produced by selecting the p-type semiconductor material, the n-type semiconductor material, and the solvent described above, with a filter having a pore diameter of 0.5 μm or less.
The method for producing the ink composition of the present embodiment may be a method for producing an ink composition for producing a photoelectric conversion element,the process comprises the following steps: a preparation step of preparing a plurality of polymer compounds as p-type semiconductor materials; the polymer compound prepared in the preparation step is screened for a z-average molecular weight of less than 5.0X10 5 A screening step of using the polymer compound of (a) as a p-type semiconductor material; and a step of mixing the p-type semiconductor material, the n-type semiconductor material, and the solvent, which are selected in the step of selecting, to produce an ink composition.
For screening z-average molecular weights less than 5.0X10 5 The polymer compound prepared in the preparation step may be subjected to a screening step as a screening step by measuring the z-average molecular weight of the polymer compound by the measurement method described above, for example, and then screening the polymer compound based on the measured z-average molecular weight.
In this embodiment, the ink composition may be produced by any suitable method known in the art. In particular, when 2 or more solvents are used, the composition can be produced, for example, by the following method: a method of preparing a mixed solvent by mixing the above-described solvent and another solvent, and then adding a p-type semiconductor material and an n-type semiconductor material to the mixed solvent; and a method of preparing (1 st) a composition comprising adding a p-type semiconductor material to a solvent, preparing (2 nd) a composition comprising adding an n-type semiconductor material to another solvent separately therefrom, and mixing the obtained 2 or more compositions, in other words, a method of preparing a composition comprising a step of preparing 2 or more compositions and a step of preparing an ink composition comprising a step of mixing the 2 or more compositions; etc.
In preparing the ink composition, the solvent (and other solvents) may be mixed with the p-type semiconductor material and the n-type semiconductor material by heating to a temperature below the boiling point of the solvent.
In this embodiment, the step of preparing the ink composition is preferably performed under the condition of 0 ℃ to 200 ℃, and preferably under the condition of 0 ℃ to 100 ℃.
In the present embodiment, in the step of filtering the prepared ink composition, specifically, in the preparation (production) of the ink composition, after the solvent (and other solvents) is mixed with the p-type semiconductor material and the n-type semiconductor material, the obtained mixture (ink composition) may be filtered according to a conventional method using a filter having a predetermined pore size.
In the present embodiment, examples of the filter that can be used for filtration include a filter made of a fluororesin such as cellulose acetate, glass fiber, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), and the like.
In this embodiment, the pore diameter that can be used for the filter is preferably 1 μm or less, more preferably 0.5 μm or less, still 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 still more preferably 0.1 μm to 0.5 μm, from the viewpoints of the availability of the filter, the filtration efficiency, and the suppression of occurrence of defects in the formed functional layer (active layer).
4. Use of ink composition
The ink composition of the present embodiment is generally used for forming a film containing a p-type semiconductor material and an n-type semiconductor material.
The ink composition of the present embodiment is suitably used for forming an active layer included in a photoelectric conversion element. In particular, the ink composition of the present embodiment is particularly suitable for use in forming an active layer included in a photodetection element to which a reverse bias voltage is applied at the time of use.
5. Cured film of ink composition
After forming a film using the ink composition of the present embodiment, the solvent is removed from the film, and the film is cured, whereby a cured film of the ink composition can be formed. The cured film of the ink composition can be suitably used for forming a functional layer, particularly an active layer, included in the photodetecting element.
The cured film of the ink composition may be manufactured by any suitable manufacturing method.
In the present embodiment, the method for producing a cured film of an ink composition includes a step (i) of applying the ink composition to a coating object to obtain a coating film, and a step (ii) of removing a solvent from the obtained coating film. Hereinafter, the steps (i) and (ii) will be described.
[ procedure (i) ]
In the step (i), as a method of applying the ink composition to the object to be coated, any of the conventionally known application methods described above can be used. In this embodiment, the coating method is preferably a slit coating method, a doctor blade coating method, a spin coating method, a micro gravure coating method, a gravure printing 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 still more preferably a slit coating method or a spin coating method.
In the step (i), the ink composition is applied to an arbitrary object to be coated. The ink composition may be applied to a functional layer that the photoelectric conversion element may include, for example, an electrode (anode or cathode), an electron transport layer, or a hole transport layer in a process of manufacturing the photoelectric conversion element.
[ procedure (ii) ]
In the step (ii), any suitable method may be used as a method for removing the solvent from the coating film of the ink composition formed in the step (i). Examples of the method for removing the solvent include drying methods such as hot air drying, infrared heating drying, flash annealing drying, and vacuum drying.
6. Photoelectric conversion element
(1) Construction of photoelectric conversion element
The photoelectric conversion element of the present embodiment includes the 1 st electrode, the 2 nd electrode, and an active layer provided between the 1 st electrode and the 2 nd electrode, and the active layer is the cured film described above.
Hereinafter, a configuration example of the photoelectric conversion element of the present embodiment will be specifically described with reference to the drawings.
Fig. 1 is a diagram schematically showing a configuration example of a photoelectric conversion element.
As shown in fig. 1, the photoelectric conversion element 10 is provided on a support substrate 11. The photoelectric conversion element 10 includes: the 1 st electrode 12 provided so as to be in contact with the support substrate 11, the electron transport layer 13 provided so as to be in contact with the 1 st electrode 12, the active layer 14 provided so as to be in contact with the electron transport layer 13, the hole transport layer 15 provided so as to be in contact with the active layer 14, and the 2 nd electrode 16 provided so as to be in contact with the hole transport layer 15. In this configuration example, a sealing member 17 is further provided so as to contact the 1 st electrode 16.
Hereinafter, the constituent elements that can be included in the photoelectric conversion element of the present embodiment will be specifically described.
(substrate)
The photoelectric conversion element is generally formed on a substrate (supporting substrate). In addition, the sealing may be performed by a substrate (sealing substrate). One of a pair of electrodes consisting of the 1 st electrode and the 2 nd electrode is generally formed on the substrate. The material of the substrate is not particularly limited as long as it is a material that does not undergo chemical change when forming a layer containing an organic compound in particular.
Examples of the material of the substrate include glass, plastic, polymer film, and silicon. In the case of using an opaque substrate, it is preferable that an electrode provided on the opposite side of the electrode on the opaque substrate side (in other words, an electrode on the side away from the opaque substrate) is made transparent or translucent.
(electrode)
The photoelectric conversion element includes a 1 st electrode and a 2 nd electrode as a pair of electrodes. In order to make light incident, at least one of the 1 st electrode and the 2 nd electrode is preferably made transparent or translucent.
Examples of the material of the transparent or semitransparent electrode include a conductive metal oxide film and a semitransparent metal thin film. Specifically, indium oxide, zinc oxide, tin oxide, indium Tin Oxide (ITO), indium Zinc Oxide (IZO), NESA, and other conductive materials, gold, platinum, silver, and copper, which are composites of these materials, are exemplified. As a material of the transparent or semitransparent electrode, ITO, IZO, and tin oxide are preferable. As the electrode, a transparent conductive film using an organic compound such as polyaniline or a derivative thereof, polythiophene or a derivative thereof as a material can be used. The transparent or semitransparent electrode may be the 1 st electrode or the 2 nd electrode.
As long as one of the pair of electrodes is transparent or translucent, the other electrode may be a low-light-transmittance electrode. Examples of the material of the electrode having low light transmittance include metals and conductive polymers. Specific examples of the material of the electrode having 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, ytterbium, and the like, alloys of 2 or more of these metals, or alloys of 1 or more of these metals with 1 or more metals selected from the group consisting of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, and tin, graphite interlayer compounds, polyaniline and derivatives thereof, polythiophene and derivatives thereof. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy.
(active layer)
The photoelectric conversion element of the present embodiment includes the cured film of the ink composition described above as an active layer. The active layer of the present embodiment has a bulk heterojunction structure.
In this embodiment, the thickness of the active layer is not particularly limited. The thickness of the active layer may be set to any appropriate thickness in consideration of, for example, the balance between suppression of dark current and extraction of generated photocurrent. In particular, from the viewpoint of further reducing dark current, the thickness of the active layer is preferably 100nm or more, more preferably 100nm or more, and still more preferably 200nm or more. The thickness of the active layer is preferably 5 μm or less, more preferably 1 μm or less, and still more preferably 600nm or less.
(intermediate layer)
As shown in fig. 1, the photoelectric conversion element of the present 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.
Examples of the material used for the intermediate layer include metals such as calcium, inorganic oxide semiconductors such as molybdenum oxide and zinc oxide, and mixtures of PEDOT (poly (3, 4-ethylenedioxythiophene)) and PSS (poly (4-styrenesulfonate)), such as PEDOT: PSS.
The intermediate layer may be formed by any suitable forming method known in the art. The intermediate layer may be formed by vacuum vapor deposition or by a coating method similar to the method for forming the active layer.
As shown in fig. 1, the photoelectric conversion element of the present embodiment preferably includes an electron transport layer between the 1 st 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 may not include an electron transport layer.
The electron transport layer provided in contact with the 1 st electrode is sometimes specifically referred to as an electron injection layer. The electron transport layer (electron injection layer) provided in contact with the 1 st electrode has a function of promoting injection of electrons into the 1 st electrode. The electron transport layer (electron injection layer) may also be in contact with the active layer.
The electron transport layer comprises an electron transport material. Examples of the electron-transporting material include polyalkyleneimines and derivatives thereof, polymer compounds containing fluorene structures, metals such as calcium, and metal oxides.
Examples of the polyalkyleneimine and its derivatives include polymers obtained by polymerizing one or more of ethyleneimine, propyleneimine, butyleneimine, dimethylethyleneimine, pentyleneimine, hexyleneimine, heptyleneimine, octyleneimine and the like having 2 to 8 carbon atoms, particularly, an alkyleneimine having 2 to 4 carbon atoms by a conventional method, and polymers obtained by chemically modifying these compounds by reacting them with various compounds. As the polyalkyleneimine and its derivative, polyethyleneimine (PEI) and ethoxylated Polyethyleneimine (PEIE) are preferable.
Examples of the polymer compound containing a fluorene structure include poly [ (9, 9-bis (3 '- (N, N-dimethylamino) propyl) -2, 7-fluorene) -o-2, 7- (9, 9' -dioctylfluorene) ] (PFN) and PFN-P2.
Examples of the metal oxide 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.
Examples of other electron-transporting materials include poly (4-vinylphenol) and perylene diimide.
The photoelectric conversion element of the present embodiment preferably has a structure in which an intermediate layer is an electron transport layer, and a substrate (support substrate), a 1 st electrode, an electron transport layer, an active layer, a hole transport layer, and a 2 nd electrode are stacked in this order in contact with each other.
As shown in fig. 1, the photoelectric conversion element of the present embodiment preferably includes a hole transport layer as an intermediate layer between the 2 nd electrode and the active layer. The hole transport layer has a function of transporting holes from the active layer to the 2 nd electrode. The hole transport layer may be connected to the 2 nd electrode.
The hole transport layer may also be in contact with the active layer.
In another embodiment, the photoelectric conversion element may not include a hole transport layer.
The hole transport layer provided in contact with the 2 nd electrode is sometimes specifically referred to as a hole injection layer. The hole transport layer (hole injection layer) provided in contact with the 2 nd electrode has a function of promoting injection of holes generated in the active layer into the 2 nd electrode.
The hole transport layer contains a hole transporting material. Examples of the hole-transporting material include polythiophene and its derivatives, aromatic amine compounds, polymer compounds containing a structural unit having an aromatic amine residue, cuSCN, cuI, niO, and tungsten oxide (WO) 3 ) Molybdenum oxide (MoO) 3 )。
(sealing member)
The photoelectric conversion element of the present embodiment preferably further includes a sealing member, and a sealing body sealed by the sealing member is formed.
Any suitable known sealing member may be used. As an example of the sealing member, a combination of a glass substrate as a substrate (sealing substrate) and a sealing material (adhesive) such as a UV curable resin is given.
The sealing member may be a sealing layer having a layer structure of 1 or more layers. Examples of the layer constituting the sealing layer include a gas barrier layer and a gas barrier film.
The sealing layer is preferably formed of 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 as the material of the sealing layer include organic materials such as trifluoroethylene, polytrifluoroethylene (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.
The sealing member is generally composed of a material that can be used for the photoelectric conversion element, for example, a material that can withstand a heat treatment that may be performed when assembled into a device of an application example described later.
(2) Method for manufacturing photoelectric conversion element
The photoelectric conversion element of the present embodiment can be manufactured by any conventionally known suitable manufacturing method. The photoelectric conversion element of the present embodiment may be manufactured by combining steps suitable for materials selected in forming the constituent elements.
Hereinafter, as an embodiment of the present invention, a method for manufacturing a photoelectric conversion element having a structure in which a substrate (support substrate), a 1 st electrode, a hole transport layer, an active layer, an electron transport layer, and a 2 nd electrode are in contact with each other in this order will be described.
(step of preparing a substrate)
In this step, for example, a support substrate provided with the 1 st electrode is prepared. Further, a substrate provided with a conductive thin film formed of the above-described electrode material is commercially available, and the 1 st electrode is formed by patterning the conductive thin film as necessary, whereby a support substrate provided with the 1 st electrode is prepared.
In the method for manufacturing the photoelectric conversion element according to the present embodiment, the method for forming the 1 st electrode when the 1 st electrode is formed on the support substrate is not particularly limited. The 1 st electrode may be formed by any suitable method known in the art, such as vacuum deposition, sputtering, ion plating, or coating, on the structure (e.g., support substrate, active layer, or hole transport layer) on which the 1 st electrode is to be formed.
(step of Forming hole transporting layer)
The method for manufacturing the photoelectric conversion element may include a step of forming a hole transport layer (hole injection layer) provided between the active layer and the 1 st electrode.
The method for forming the hole transport layer is not particularly limited. In order to simplify the step of forming the hole transport layer, the hole transport layer is preferably formed by any conventionally known suitable coating method.
The hole transport layer can be formed by, for example, a coating method or a vacuum deposition method using a coating liquid containing a solvent and a material constituting the hole transport layer described above.
(active layer Forming step)
In the method for manufacturing a photoelectric conversion element according to the present embodiment, an active layer is formed over a hole transport layer. The active layer may be formed by any suitable known forming process. In this embodiment, the active layer can be produced by a coating method using the ink composition described above.
The active layer may be formed in the same manner as the "cured film" described above. In this embodiment mode, the active layer can be formed by a process including: a step of forming a coating film by applying an ink composition containing a p-type semiconductor material, an n-type semiconductor material, and a solvent onto the hole transport layer; and then drying the coating film.
(step of Forming an Electron transporting layer)
The method for manufacturing a photoelectric conversion element according to the present embodiment may include a step of forming an electron transport layer (electron injection layer) provided so as to be in contact with an active layer.
The method for forming the electron transport layer is not particularly limited. The electron transport layer is preferably formed by any conventionally known suitable vacuum deposition method, from the viewpoint of facilitating the formation process of the electron transport layer.
(step of forming No. 2 electrode)
The method for forming the 2 nd electrode is not particularly limited. The 2 nd electrode may be formed by any suitable method known in the art, such as a coating method, a vacuum deposition method, a sputtering method, an ion plating method, or a plating method, for example, by using the electrode materials exemplified above. Through the above steps, the photoelectric conversion element of the present embodiment is manufactured.
(step of forming seal)
In forming the sealing body, any conventionally known sealing material (adhesive) and substrate (sealing substrate) are used in the present embodiment. Specifically, after a sealing material such as a UV curable resin is applied to the support substrate so as to surround the periphery of the photoelectric conversion element to be manufactured, the sealing material is bonded without a gap, and then the photoelectric conversion element is sealed in the gap between the support substrate and the sealing substrate by a method such as irradiation of UV light suitable for the selected sealing material, whereby a sealed body of the photoelectric conversion element can be obtained.
(3) Use of photoelectric conversion element
Examples of the use of the photoelectric conversion element according to the present embodiment include a photodetector and a solar cell.
More specifically, the photoelectric conversion element of the present embodiment can circulate a photocurrent by irradiating light from the transparent or semitransparent electrode side in a state where a voltage (reverse bias voltage) is applied between the electrodes, and can operate as a photodetecting element (photosensor). In addition, the light detection element may be integrated into a plurality of light detection elements to be used as an image sensor. The photoelectric conversion element of the present embodiment can be particularly suitably used as a light detection element.
The photoelectric conversion element according to the present embodiment can generate photoelectromotive force between electrodes by irradiation with light, and can operate as a solar cell. The solar cell module may also be manufactured by integrating a plurality of photoelectric conversion elements.
(4) Application example of photoelectric conversion element
The photoelectric conversion element according to the present embodiment can be suitably applied as a light detection element to detection units included in various electronic devices such as workstations, personal computers, portable information terminals, entrance/exit management systems, digital cameras, and medical equipment.
The photoelectric conversion element according to the present embodiment is suitably applicable to an image detection unit (for example, an image sensor such as an X-ray image sensor) for a solid-state image pickup device such as a CMOS image sensor, a fingerprint detection unit, a face detection unit, a vein detection unit, an iris detection unit, and a detection unit (for example, a near infrared sensor) of a biological information authentication device that detects a part of a specific feature of a living body, and a detection unit of an optical biosensor such as a pulse oximeter, which are included in the above-described exemplary electronic device.
The photoelectric conversion element according to the present embodiment can be further suitably applied to a Time-of-flight (TOF) type distance measuring device (TOF type distance measuring device) as an image detecting unit for a solid-state imaging device.
In the TOF type distance measuring device, a distance is measured by receiving reflected light, which is obtained by reflecting light emitted from a light source to an object to be measured, by a photoelectric conversion element. Specifically, the time of flight until the irradiation light emitted from the light source is reflected by the measurement object and returned as reflected light is detected, and the distance to the measurement object is obtained. There are direct TOF and indirect TOF modes in the TOF type. In the direct TOF method, the difference between the time when light is irradiated from the light source and the time when reflected light is received by the photoelectric conversion element is directly measured, and in the indirect TOF method, the distance is measured by converting the change in charge accumulation amount depending on the time of flight into a time change. Among distance measurement principles used in the indirect TOF method for obtaining a time of flight by charge accumulation, there are a continuous wave (in particular, sine wave) modulation method and a pulse modulation method for obtaining a time of flight from a phase of an emission light from a light source and a reflected light reflected by a measurement object.
The following describes, with reference to the drawings, a configuration example in which 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 (for example, a fingerprint recognition device, a vein recognition device, and the like), and an image detection unit of a TOF type distance measuring device (indirect TOF system) are appropriately applied to the detection units of the photoelectric conversion elements of the present embodiment.
(image detection section for solid-state imaging device)
Fig. 2 is a diagram schematically showing a configuration example of an image detection section for a solid-state imaging device.
The image detection unit 1 includes: a CMOS transistor substrate 20; an interlayer insulating film 30 provided so as to cover the CMOS transistor substrate 20; the photoelectric conversion element 10 of the embodiment of the present invention provided on the interlayer insulating film 30; an interlayer wiring portion 32 that is provided so as 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 so as to cover the photoelectric conversion element 10; and a color filter 50 provided on the sealing layer 40.
The CMOS transistor substrate 20 has any suitable structure known in the art in a manner corresponding to the design.
The CMOS transistor substrate 20 includes transistors, capacitors, and the like formed within the thickness of the substrate, and includes functional elements such as CMOS transistor circuits (MOS transistor circuits) for realizing various functions.
Examples of the functional element include a floating diffusion element, a reset transistor, an output transistor, and a selection transistor.
A signal readout circuit or the like is fabricated on the CMOS transistor substrate 20 by such functional elements, wirings, and the like.
The interlayer insulating film 30 may be made of any suitable insulating material known in the art, such as silicon oxide or insulating resin. The interlayer wiring portion 32 may be made of any conventionally known conductive material (wiring material), such as copper or tungsten. The interlayer wiring portion 32 may be, for example, an in-hole wiring formed simultaneously with the formation of the wiring layer, or may be an embedded plug formed separately from the wiring layer.
The sealing layer 40 may be made of any conventionally known suitable material provided that it can prevent or inhibit permeation of harmful substances such as oxygen and water, which may deteriorate the functionality of the photoelectric conversion element 10. The sealing layer 40 may have the same structure as the sealing member 17 described above.
As the color filter 50, for example, a primary color filter which is made of any appropriate material known in the art and corresponds to the design of the image detection section 1 may be used. As the color filter 50, a complementary color filter which can be reduced in thickness as compared with the primary color filter may be used. As the complementary color filter, for example, a color filter of 3 types of (yellow, cyan, magenta), 3 types of (yellow, cyan, transparent), 3 types of (yellow, transparent, magenta), and 3 types of combinations of (transparent, cyan, magenta) may be used. These color filters may be set to any suitable configuration corresponding to the design of the photoelectric conversion element 10 and the CMOS transistor substrate 20, provided that color image data can be generated.
The light received by the photoelectric conversion element 10 through the color filter 50 is converted into an electric signal corresponding to the amount of light received by the photoelectric conversion element 10, and the electric signal is output to the outside of the photoelectric conversion element 10 through the electrode in the form of a light-receiving signal, that is, an electric signal corresponding to the object to be photographed.
Then, the light receiving signal outputted from the photoelectric conversion element 10 is inputted to the CMOS transistor substrate 20 via the interlayer wiring portion 32, is read out by a signal reading circuit formed on the CMOS transistor substrate 20, and is subjected to signal processing by any other suitable conventionally known functional portion not shown, thereby generating image information based on the object to be photographed.
(fingerprint detection section)
Fig. 3 is a diagram schematically showing a configuration example of a fingerprint detection section integrally configured with a display device.
The display device 2 of the portable information terminal includes: a fingerprint detection section 100 including the photoelectric conversion element 10 according to the embodiment of the present invention as a main constituent element; and a display panel section 200 provided on the fingerprint detection section 100 and displaying a specific image.
In this configuration example, the fingerprint detection section 100 is provided in a region that coincides with the display region 200a of the display panel section 200. In other words, the display panel section 200 is integrally laminated above the fingerprint detection section 100.
In the case of fingerprint detection only in a partial region in the display region 200a, the fingerprint detection section 100 may be provided only in correspondence with the partial region.
The fingerprint detection section 100 includes the photoelectric conversion element 10 according to the embodiment of the present invention as a functional section that performs a substantial function. The fingerprint detection section 100 may include any suitable conventionally known member such as a protection film (not shown), a support substrate, a sealing member, a barrier film, a band-pass filter, and an infrared cut film so as to correspond to a design for obtaining desired characteristics. The fingerprint detection section 100 may be configured as the image detection section described above.
The photoelectric conversion element 10 may be included in the display region 200a in any manner. For example, the plurality of photoelectric conversion elements 10 may be arranged in a matrix.
As described above, the photoelectric conversion element 10 is provided on the support substrate 11, and the electrodes (first electrodes or second electrodes) are provided on the support substrate 11 in a matrix, for example.
The light received by the photoelectric conversion element 10 is converted into an electric signal corresponding to the amount of light received by the photoelectric conversion element 10, and the electric signal is outputted to the outside of the photoelectric conversion element 10 as a light-receiving signal, that is, an electric signal corresponding to the photographed fingerprint, via the electrode.
In this configuration example, the display panel section 200 is configured as an organic electroluminescence display panel (organic EL display panel) including a touch sensor panel. The display panel section 200 may be configured by a display panel having any suitable conventionally known configuration, such as a liquid crystal display panel including a light source such as a backlight, instead of the organic EL display panel.
The display panel section 200 is provided on the fingerprint detection section 100 described above. The display panel section 200 includes an organic electroluminescent element (organic EL element) 220 as a functional section that performs a substantial function. The display panel section 200 may further include any suitable conventionally known substrate (support substrate 210 or sealing substrate 240) such as a conventionally known glass substrate, a sealing member, a polarizing plate such as a barrier film or a circularly polarizing plate, and any suitable conventionally known member such as a touch sensor panel 230 so as to correspond to desired characteristics.
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 image capturing of the fingerprint in the fingerprint detection section 100.
Here, the operation of the fingerprint detection section 100 will be briefly described.
In performing fingerprint recognition, the fingerprint detection section 100 detects a fingerprint using light emitted by the organic EL element 220 of the display panel section 200. Specifically, the light emitted from the organic EL element 220 is transmitted through the constituent elements existing between the organic EL element 220 and the photoelectric conversion element 10 of the fingerprint detection section 100, and is reflected by the skin (finger surface) of the finger tip of the finger placed so as to be in contact with the surface of the display panel section 200 in the display area 200 a. At least a part of the light reflected by the finger surface is received by the photoelectric conversion element 10 through the constituent elements present therebetween, and converted into an electric signal according to the light receiving amount of the photoelectric conversion element 10. Then, image information related to the fingerprint of the finger surface is constructed from the converted electric signals.
The portable information terminal provided with the display device 2 performs fingerprint recognition by comparing the obtained image information with the fingerprint data for the pre-recorded fingerprint recognition by any suitable procedure known in the art.
(image detection section for X-ray imaging device)
Fig. 4 is a diagram schematically showing a configuration example of an image detection unit for an X-ray imaging apparatus.
The image detection unit 1 for an X-ray imaging device includes: a CMOS transistor substrate 20; an interlayer insulating film 30 provided so as to cover the CMOS transistor substrate 20; the photoelectric conversion element 10 of the embodiment of the present invention provided on the interlayer insulating film 30; an interlayer wiring portion 32 that is provided so as 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 so as to cover the photoelectric conversion element 10; a scintillator 42 provided on the sealing layer 40 and a reflection layer 44 provided so as to cover the scintillator 42; and a protective layer 46 provided so as to cover the reflective layer 44.
The CMOS transistor substrate 20 has any suitable structure known in the art in a manner corresponding to the design.
The CMOS transistor substrate 20 includes transistors, capacitors, and the like formed within the thickness of the substrate, and includes functional elements such as CMOS transistor circuits (MOS transistor circuits) for realizing various functions.
Examples of the functional element include a floating diffusion element, a reset transistor, an output transistor, and a selection transistor.
A signal readout circuit or the like is fabricated on the CMOS transistor substrate 20 by such functional elements, wirings, and the like.
The interlayer insulating film 30 may be made of any suitable insulating material known in the art, such as silicon oxide or insulating resin. The interlayer wiring portion 32 may be made of any conventionally known conductive material (wiring material), such as copper or tungsten. The interlayer wiring portion 32 may be, for example, an in-hole wiring formed simultaneously with the formation of the wiring layer, or may be an embedded plug formed separately from the wiring layer.
The sealing layer 40 may be made of any conventionally known suitable material provided that it can prevent or inhibit permeation of harmful substances such as oxygen and water, which may deteriorate the functionality of the photoelectric conversion element 10. The sealing layer 40 may have the same structure as the sealing member 17 described above.
The scintillator 42 may be made of any conventionally known suitable material corresponding to the design of the image detection unit 1 for an X-ray imaging apparatus. As examples of suitable materials for the scintillator 42, inorganic crystals of inorganic materials such as CsI (cesium iodide), naI (sodium iodide), znS (zinc sulfide), GOS (gadolinium oxysulfide), GSO (gadolinium silicate) and the like can be used; organic crystals of organic materials such as anthracene, naphthalene, stilbene, and the like; an organic liquid obtained by dissolving an organic material such as diphenyl oxazole (PPO) or Terphenyl (TP) in an organic solvent such as toluene, xylene or dioxane; xenon, helium, and the like, plastics, and the like.
The above-described components may be set to any suitable arrangement corresponding to the design of the photoelectric conversion element 10 and the CMOS transistor substrate 20, provided that the scintillator 42 can convert incident X-rays into light having a wavelength centered on the visible light region and generate image data.
The reflective layer 44 reflects the light converted by the scintillator 42. The reflection layer 44 can reduce loss of converted light and increase detection sensitivity. In addition, the reflective layer 44 may also block light directly incident from the outside.
The protective layer 46 may be made of any suitable material known in the art, provided that it can prevent or inhibit permeation of harmful substances such as oxygen and water that may degrade the functionality of the scintillator 42.
Here, the operation of the image detection unit 1 for an X-ray imaging apparatus having the above-described configuration will be briefly described.
When radiation energy such as X-rays or γ -rays is incident on the scintillator 42, the scintillator 42 absorbs the radiation energy and converts it into light (fluorescence) having a wavelength ranging from ultraviolet to infrared with the visible region as the center. Then, the light converted by the scintillator 42 is received by the photoelectric conversion element 10.
In this way, the light received by the photoelectric conversion element 10 via the scintillator 42 is converted into an electric signal corresponding to the amount of light received by the photoelectric conversion element 10, and the electric signal is outputted to the outside of the photoelectric conversion element 10 via the electrode in the form of a light-receiving signal, that is, an electric signal corresponding to the subject. The radiation energy (X-ray) as the detection target may be incident from any one of the scintillator 42 side and the photoelectric conversion element 10 side.
Then, the light receiving signal outputted from the photoelectric conversion element 10 is inputted to the CMOS transistor substrate 20 via the interlayer wiring portion 32, is read out by a signal reading circuit formed on the CMOS transistor substrate 20, and is subjected to signal processing by any other suitable conventionally known functional portion not shown, thereby generating image information based on the object to be photographed.
(vein detection section)
Fig. 5 is a diagram schematically showing a configuration example of a vein detection unit for a vein recognition apparatus.
The vein detection unit 300 for the vein recognition apparatus is constituted by: a cover portion 306 defining an insertion portion 310 into which a finger (for example, a fingertip, a finger, and a palm of 1 or more fingers) to be measured is inserted during measurement; a light source unit 304 provided in the cover unit 306 and configured to irradiate light to be measured; the photoelectric conversion element 10 receives the light irradiated from the light source unit 304 via the measurement object; a support substrate 11 for supporting the photoelectric conversion element 10; and a glass substrate 302 disposed so as to face the support substrate 11 with the photoelectric conversion element 10 interposed therebetween, and separated from the cover 306 by a predetermined distance, and defining an insertion portion 306 together with the cover 306.
In this configuration example, the light source unit 304 is shown as a transmission type imaging system configured integrally with the cover unit 306 so as to be separated from the photoelectric conversion element 10 and sandwich the measurement object during use, but the light source unit 304 is not necessarily required to be located on the cover unit 306 side.
As long as the light from the light source unit 304 can be efficiently irradiated to 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 set.
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 a substantial function. The vein detection unit 300 may include any suitable conventionally known member such as a protection film (not shown), a sealing member, a blocking film, a band-pass filter, a near infrared ray transmission filter, a visible light blocking film, and a finger placement guide so as to correspond to a design for obtaining desired characteristics. The configuration of the image detection unit 1 described above may be adopted for the vein detection unit 300.
The photoelectric conversion element 10 may be included in any manner. For example, the plurality of photoelectric conversion elements 10 may be arranged in a matrix.
As described above, the photoelectric conversion element 10 is provided on the support substrate 11, and the electrodes (first electrodes or second electrodes) are provided on the support substrate 11 in a matrix, for example.
The light received by the photoelectric conversion element 10 is converted into an electric signal corresponding to the amount of light received by the photoelectric conversion element 10, and the electric signal is outputted to the outside of the photoelectric conversion element 10 as a light-receiving signal, that is, an electric signal corresponding to the imaged vein via the electrode.
In the case of vein detection (in use), the measurement object may or may not be in contact with the glass substrate 302 on the photoelectric conversion element 10 side.
Here, the operation of the vein detection unit 300 will be briefly described.
In the vein detection, the vein detection unit 300 detects a vein pattern of a measurement object using light emitted from the light source unit 304. Specifically, the light emitted from the light source unit 304 is transmitted through the measurement object and converted into an electrical signal corresponding to the light receiving amount of the photoelectric conversion element 10. Then, image information of the vein pattern of the measurement object is constituted by the converted electric signal.
In the vein recognition apparatus, vein recognition is performed by comparing the obtained image information with vein data for vein recognition recorded in advance by any suitable procedure known in the art.
(image detection part for TOF distance measuring device)
Fig. 6 is a diagram schematically showing a configuration example of an image detection unit for an indirect TOF type distance measuring device.
The image detection unit 400 for a TOF type distance measuring device includes: a CMOS transistor substrate 20; an interlayer insulating film 30 provided so as to cover the CMOS transistor substrate 20; the photoelectric conversion element 10 of the embodiment of the present invention provided on the interlayer insulating film 30; 2 floating diffusion layers 402 arranged apart so as to sandwich the photoelectric conversion element 10; an insulating layer 40 provided so as to cover the photoelectric conversion element 10 and the floating diffusion layer 402; and 2 photo gates 404 disposed on the insulating layer 40 and disposed apart from each other.
A part of the insulating layer 40 is exposed from the gaps of the 2 divided photo gates 404, and the remaining region is shielded by the shielding portion 406. The CMOS transistor substrate 20 and the floating diffusion layer 402 are electrically connected to each other through the interlayer wiring portion 32 provided so as to penetrate the interlayer insulating film 30.
The interlayer insulating film 30 may be made of any suitable insulating material known in the art, such as silicon oxide or insulating resin. The interlayer wiring portion 32 may be made of any conventionally known conductive material (wiring material), such as copper or tungsten. The interlayer wiring portion 32 may be, for example, an in-hole wiring formed simultaneously with the formation of the wiring layer, or may be an embedded plug formed separately from the wiring layer.
In this configuration example, the insulating layer 40 may have any conventionally known suitable configuration such as a field oxide film made of silicon oxide.
The photogate 404 may be constructed of any suitable material known in the art, such as polysilicon.
The image detection unit 400 for a 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 a substantial function. The image detection unit 400 for a TOF type distance measuring device may include any suitable conventionally known member such as a protection film (not shown), a support substrate, a sealing member, a blocking film, a band-pass filter, and an infrared cut film so as to correspond to a design for obtaining desired characteristics.
Here, the operation of the image detection unit 400 for a TOF type distance measuring device will be briefly described.
Light is emitted from the light source, reflected by the measurement object, and the reflected light is received by the photoelectric conversion element 10. Between the photoelectric conversion element 10 and the floating diffusion layer 402, 2 photoelectric gates 404 are provided, and by alternately applying pulses, signal charges generated by the photoelectric conversion element 10 are transferred to any one of the 2 floating diffusion layers 402, and charges are accumulated in the floating diffusion layer 402. When the light pulse reaches the timing at which the 2 photo gates 404 are opened so as to equally span, the amount of charge stored in the 2 floating diffusion layers 402 is equal. If the light pulse reaches one of the photo gates 404 with respect to the timing at which the light pulse reaches the other photo gate 404, the amount of charge accumulated in the 2 floating diffusion layers 402 varies.
The difference in the amount of charge accumulated in the floating diffusion layer 402 depends on the delay time of the light pulse. Since the distance L to the measurement target is l= (1/2) ctd using the relationship between the round trip time td of light and the speed c of light, if the delay time can be estimated from the difference in the charge amounts of the 2 floating diffusion layers 402, the distance to the measurement target can be obtained.
The light receiving amount of the light received by the photoelectric conversion element 10 is converted into an electric signal as a difference in the amount of electric charge accumulated in the 2 floating diffusion layers 402, and is output to the outside of the photoelectric conversion element 10 as a light receiving signal, that is, an electric signal corresponding to the measurement object.
Then, the light receiving signal outputted from the floating diffusion layer 402 is inputted to the CMOS transistor substrate 20 via the interlayer wiring portion 32, and is read out by a signal reading circuit formed on the CMOS transistor substrate 20, and is subjected to signal processing by any other suitable conventionally known functional portion not shown, thereby generating distance information based on the measurement object.
7. Light detecting element
As described above, the photoelectric conversion element of the present embodiment may have a light detection function of converting irradiated light into an electrical signal corresponding to the amount of light received 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 used 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 performing voltage control or the like in addition to the photoelectric conversion element.
Examples
Hereinafter, examples are shown for further explaining the present invention in detail. The present invention is not limited to the following examples.
< semiconductor Material >
As the material P-1, a material synthesized by the method described in reference to WO2013/051676 was used.
The material P-2 was a product name of 1-Material Co., ltd: PCE-10, obtained from the market and used.
The material N-1 is a product name of the company front Carbon: e100, obtained from the market and used.
The material N-2 was a product name of 1-Material Co., ltd: diPDI, obtained from the market and used.
The material N-3 was a product name of 1-Material Co., ltd: ITIC, obtained from the market and used.
Specific structures of the materials P-1 and P-2 as the P-type semiconductor material and the materials N-1 to N-3 as the N-type semiconductor material used in the present embodiment are shown in tables 1 and 2 below.
TABLE 1
(Table 1)
TABLE 2
(Table 2)
< determination of molecular weight >
The z-average molecular weight (Mz) and the weight-average molecular weight (Mw) of the p-type semiconductor material were obtained by Gel Permeation Chromatography (GPC) (LC-20 AT manufactured by shimadzu corporation) based on the z-average molecular weight (Mz) and the weight-average molecular weight (Mw) in terms of polystyrene. Hereinafter, specific description will be made.
As a mobile phase of GPC, o-dichlorobenzene was used, and the solution was flowed at a flow rate of 1.0 mL/min. As a column, shodex KD-806M, manufactured by Showa electric company was used, and as a guard column, shodex KD-G, manufactured by Showa electric company was used.
As the detector, a UV-vis detector (manufactured by Shimadzu corporation, SPD-M20A) and a differential refractive index detector (manufactured by Shimadzu corporation, RID-10A) were used.
The compound (polymer) to be measured was mixed with 1-chloronaphthalene as a solvent so as to have a concentration of 0.05 mass%, and the mixture was stirred at 80℃for 2 hours to dissolve the compound (polymer) to prepare a solution.
The obtained solution was poured into 10. Mu.L of the above-mentioned measuring apparatus (GPC) as a sample, and the z-average molecular weight (Mz) and the weight-average molecular weight (Mw) were measured.
Example 1 ]
[ preparation of ink composition ]
In 1,2,3, 4-tetrahydronaphthalene, a material P-1 as a P-type semiconductor material was mixed so as to be 0.8 mass% with respect to the total mass of the ink composition, and a material N-1 as an N-type semiconductor material was mixed so as to be 1.6 mass% with respect to the mass of the ink composition, and stirred at 60 ℃ for 6 hours, thereby obtaining an ink composition (I-1).
[ test of filterability of ink composition ]
Using the ink composition prepared as described above, a filterability test of the ink composition was performed.
Specifically, a filter having a predetermined pore diameter was used to evaluate whether or not the ink composition was able to pass through the filter. That is, the case where the ink composition was able to pass through the filter and was able to be filtered was evaluated as good filterability (o), and the case where the ink composition was unable to pass through the filter and was clogged and was unable to be filtered was evaluated as poor filterability (x).
More specifically, 10g of the ink composition (I-1) prepared as described above was added to a stainless steel frame (KS 047, manufactured by Advantec Toyo Co., ltd.) equipped with a PTFE filter having a pore size of 0.5. Mu.m, and a filtration test was performed.
As a result, the ink composition I-1 was allowed to permeate without clogging the PTFE filter, and the filtration was completed. Therefore, filterability was evaluated as good (good). The results are also shown in table 1.
< examples 2 to 6 and comparative example 1>
An ink composition was prepared and subjected to a filtration test in the same manner as in example 1, except that a material P-1 having a z-average molecular weight (Mz) and a weight-average molecular weight (Mw) shown in table 3 below was used as the P-type semiconductor material. The results are also shown in table 3 below.
TABLE 3
(Table 3)
Example 7 ]
[ ink composition ]
An ink composition (I-8) was prepared in the same manner as in example 1, except that the material P-1 was used as the P-type semiconductor material, the material P-1 was mixed so as to be 2.0 mass% with respect to the total mass of the ink composition, and the material N-1 was mixed so as to be 1.0 mass% with respect to the total mass of the ink composition, as the N-type semiconductor material.
[ test of filterability of ink composition ]
The filterability test was performed in the same manner as in example 1.
As a result, ink composition I-8 was allowed to permeate without clogging the PTFE filter, and the filtration was completed. Therefore, filterability was evaluated as good (good). The results are also shown in table 4 below.
TABLE 4
(Table 4)
< example 8 and comparative example 2>
An ink composition (I-9) and (I-10) was prepared and a filterability test was performed in the same manner as in example 1, except that a material P-1 having a z-average molecular weight (Mz) and a weight-average molecular weight shown in Table 3 below was used as a P-type semiconductor material, a material N-2 was used as an N-type semiconductor material, a material N-2 was mixed so as to be 1 mass% with respect to the total mass of the ink composition, and a mixed solvent in which o-xylene (97 mass%) and acetophenone (3 mass%) were mixed was used as a solvent. The results are shown in Table 5 below.
TABLE 5
(Table 5)
< example 9 and comparative example 3>
Inks (I-11) and (I-12) were prepared and tested for filterability in the same manner as in example 1, except that a material P-1 having a z-average molecular weight (Mz) and a weight-average molecular weight (Mw) shown in Table 4 below was used as a P-type semiconductor material, the material P-1 was mixed so as to be 1.0 mass% with respect to the total mass of the ink composition, a material N-3 was used as an N-type semiconductor material, the material N-3 was mixed so as to be 1.0 mass% with respect to the total mass of the ink composition, and o-dichlorobenzene was used as a solvent. The results are shown in Table 6 below.
TABLE 6
(Table 6)
< example 10 and comparative example 4>
Ink compositions (I-13) and (I-14) were prepared in the same manner as in example 1, except that a material P-2 having a z-average molecular weight (Mz) and a weight-average molecular weight (Mw) shown in Table 4 below was used as the P-type semiconductor material, and the material P-2 was mixed so as to be 0.8 mass% with respect to the total mass of the ink composition, and a filterability test was performed. The results are shown in Table 7 below.
TABLE 7
(Table 7)
As is clear from the above examples and comparative examples, the filterability of the ink composition cannot be controlled by the weight average molecular weight (Mw), and no correlation with the type, solvent, and concentration of the n-type semiconductor material used in the ink composition is observed, but if the z-average molecular weight (Mz) of the p-type semiconductor material is within the above-described predetermined range, a trial and error is not required, and the improvement can be made without clogging the filter.
Example 11 ]
[ production and evaluation of photoelectric conversion element ]
(1) Manufacture of photoelectric conversion element
(formation of cathode)
A glass substrate having an ITO film formed by a sputtering method at a thickness of 100nm (hereinafter, a laminate including a glass substrate during production will be simply referred to as a glass substrate) was prepared. The glass substrate was subjected to a cleaning treatment using an ozone UV treatment to form a cathode.
(formation of electron transport layer)
Then, the cleaned glass substrate was immersed in a solution obtained by dissolving an 80% aqueous solution of ethoxylated polyethyleneimine (37 mass% aqueous solution, manufactured by Sigma Aldrich) in water so as to be 0.1 mass% for 5 minutes, the glass substrate was lifted up, and the glass substrate was placed on a hot plate, and the coating film was dried under conditions of 100 ℃ for 10 minutes in the atmosphere.
The dried glass substrate was washed with water, the washed glass substrate was placed on a hot plate, and the coating film on the cathode was dried under the condition of 100 ℃ for 10 minutes in the atmosphere, with the coating film as an electron transport layer.
(formation of active layer)
Next, the ink composition (I-1) of 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 10Pa, 70 ℃) was performed for 5 minutes to take 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℃for 12 minutes. The thickness of the dried active layer was 200nm.
(formation of anode)
Next, a suspension (manufactured by Heraeus corporation, clevios F HC Solar) of poly (3, 4-ethylenedioxythiophene)/polystyrene sulfonic acid dissolved in water was applied to the active layer by spin coating to form a coating film. The glass substrate with the coating film formed thereon was placed in an oven, and the coating film was dried at 85℃for 30 minutes to obtain an anode. The thickness of the dried anode was about 120nm. Through the above steps, the photoelectric conversion element of example 11 was manufactured.
[ evaluation of photoelectric conversion element ]
(evaluation of External Quantum Efficiency (EQE))
The photoelectric conversion element manufactured as described above was applied with a reverse bias voltage of 2V, and in this state, a spectral sensitivity measuring device (trade name: CEP-2000 type manufactured by spectrometer company) was used to irradiate 800nm monochromatic light (photon number: 5×10) to the photoelectric conversion element 14 ) The generated current value is measured, and the EQE is obtained by a known method. The results are shown in Table 8.
< examples 12 to 14>
A photoelectric conversion element was produced in the same manner as that of example 11 except that the ink composition I-2 was used as a material of the active layer, and EQE was obtained. The results are shown in Table 8.
TABLE 8
(Table 8)
Ink composition EQE(％)
Example 11 I-1 45
Example 12 I-2 42
Example 13 I-3 54
Example 14 I-4 52
As shown in table 8, it was confirmed that the photoelectric conversion elements using the ink compositions I-1 and I-2 as the materials of the active layers functioned without any problem. In particular, it was confirmed that the weight average molecular weight using the p-type semiconductor material was more than 6.0X10 4 The photoelectric conversion element using the ink compositions I-3 and I-4 as the material of the active layer can obtain higher EQE.
Symbol description
1. Image detection unit
2. Display device
10. Photoelectric conversion element
11. 210 support substrate
12. No. 1 electrode
13. Electron transport layer
14. Active layer
15. Hole transport layer
16. No. 2 electrode
17. Sealing member
20 CMOS transistor substrate
30. Interlayer insulating film
32. Interlayer wiring part
40. Sealing layer
42. Scintillator
44. Reflective layer
46. Protective layer
50. Color filter
100. Fingerprint detection unit
200. Display panel part
200a display area
220. Organic EL element
230. Touch sensor panel
240. Sealing substrate
300. Vein detection unit
302. Glass substrate
304. Light source unit
306. Cover part
310. Insertion part
400 Image detection unit for TOF type distance measuring device
402. Floating diffusion layer
404. Photoelectric door
406. Light shielding part

Claims (9)

1. An ink composition for manufacturing a photoelectric conversion element, which is an ink composition comprising a p-type semiconductor material, an n-type semiconductor material, and a solvent, the p-type semiconductor material comprising a z-average molecular weight of less than 5.0X10 5 Is a polymer compound of (a).
2. The ink composition for manufacturing a photoelectric conversion element according to claim 1, wherein the p-type semiconductor material contains a compound having a weight average molecular weight of more than 6.0 x 10 4 Is a polymer compound of (a).
3. The ink composition for manufacturing a photoelectric conversion element according to claim 1 or 2, wherein the p-type semiconductor material contains a polymer compound having a structural unit of a thiophene skeleton.
4. The ink composition for manufacturing a photoelectric conversion element according to claim 3, wherein the p-type semiconductor material contains a polymer compound having a donor-acceptor structure.
5. The ink composition for manufacturing a photoelectric conversion element according to any one of claims 1 to 4, wherein the solvent contains an aromatic hydrocarbon.
6. The ink composition for manufacturing 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 ink composition for manufacturing 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 use in producing a photoelectric conversion element, comprising the step of filtering the ink composition with a filter having a pore diameter of 0.5 μm or less in the method for producing an ink composition according to any one of claims 1 to 7.
9. A method of manufacturing an ink composition for manufacturing a photoelectric conversion element, comprising:
a preparation step of preparing a plurality of polymer compounds as p-type semiconductor materials;
the polymer compound prepared in the preparation step is selected to have a z-average molecular weight of less than 5.0X10 5 A screening step of using the polymer compound of (a) as a p-type semiconductor material; and
and a step of mixing the p-type semiconductor material, the n-type semiconductor material, and the solvent, which are selected in the step of selecting, to produce an ink composition.
CN202280029664.3A 2021-04-21 2022-04-13 Ink composition and method for producing same Pending CN117242913A (en)

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