Charge-transporting composition

Abstract

As a charge-transporting composition which can greatly improve the dark current characteristics of the resulting element by being used in an organic photoelectric conversion element, provided is a charge-transporting composition for forming a charge-transporting thin film in an organic photoelectric conversion element. The present invention relates to a charge-transporting composition comprising: a charge-transporting substance comprising at least one polyimide polymer selected from the group consisting of polyimide precursors obtained from a diamine component having a structure represented by formula (1) or (2) and a tetracarboxylic acid component, esters of the polyimide precursors, and imides of the polyimide precursors; and an organic solvent. (In the formula, R1 represents a hydrogen atom or a monovalent organic group. And * represents a site to be bonded to another group. Any hydrogen atom forming the benzene ring may be substituted by a monovalent organic group. > # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a charge transporting composition, and more particularly, to a charge transporting composition for forming a charge transporting thin film used in an organic photoelectric conversion element. Background Art

[0002] An organic photoelectric conversion element is a device that converts light energy into electrical energy using an organic semiconductor, and examples thereof include a photo sensor, an organic solar cell, and a perovskite solar cell.

[0003] Photomultiplier tubes that use the photoelectric effect and photodiodes that use pn junctions have been used in optical sensors so far. They are widely used not only for optical sensing but also as solid-state imaging devices, such as consumer image sensors and automotive applications.

[0004] In recent years, organic photosensors using organic materials in a photoelectric conversion layer have been developed and attracted attention from the viewpoints of miniaturization, lightness, low price, and designability.

[0005] The organic photosensor is composed of a photoelectric conversion layer, a charge (hole, electron) trapping layer, electrodes (anode, cathode), and a filter.

[0006] Among these, the photoelectric conversion layer and the charge trapping layer are generally formed by vacuum deposition. However, the vacuum deposition method has problems in terms of complexity due to mass production processes, increased device costs, and material utilization efficiency.

[0007] From these aspects, water-dispersible polymer organic conductive materials such as PEDOT / PSS are sometimes used as coating materials for the hole trapping layer. However, since they are aqueous dispersions, it is difficult to completely remove water and control reabsorption of moisture, which can easily accelerate the degradation of the device.

[0008] Furthermore, the PEDOT / PSS aqueous dispersion has the property that the solid components are easily aggregated, so defects are easily generated in the coating film, and there are problems such as clogging and corrosion of the coating equipment. In addition, the heat resistance is also insufficient, and various problems remain in mass production.

[0009] In addition, in a photosensor, since it is necessary to maximize the light receiving characteristics, an external electric field is generally applied (see Patent Document 1).

[0010] By applying an external electric field, it is expected that the light receiving sensitivity and the response speed will be improved, but on the other hand, holes and electrons are injected from the electrodes, thereby increasing the dark current.

[0011] This increase in dark current is a factor causing a decrease in detection sensitivity. Therefore, in order to produce an element with high light-receiving sensitivity, it is important to suppress the dark current while exhibiting high photoelectric conversion efficiency.

[0012] Organic solar cells are solar cell elements that use organic substances in active layers and charge transport materials, and dye-sensitized solar cells developed by M. Gratzel and organic thin-film solar cells developed by CW Tang are well known (Non-Patent Documents 1 and 2).

[0013] Since both have characteristics different from the currently mainstream inorganic solar cells, such as being lightweight, thin, flexible, and capable of roll-to-roll production, they are expected to form a new market.

[0014] Furthermore, compared with existing photoelectric conversion elements using silicon-based materials, organic thin-film solar cells have the advantages of showing high photoelectric conversion efficiency even under low illumination, being able to thin the elements and miniaturize the pixels, and being able to have the properties of color filters. Therefore, they have attracted attention not only for use as solar cells, but also for their interchangeability as optical sensors, such as image sensors (Patent Documents 2, 3, Non-Patent Document 3).

[0015] Furthermore, in recent years, research results have been reported that solar cells using metal halides as compounds having a perovskite crystal structure (hereinafter referred to as "perovskite semiconductor compounds") can achieve relatively high photoelectric conversion efficiency, which has attracted attention. For example, Patent Document 4 describes a photoelectric conversion element and a solar cell including an active layer containing a perovskite semiconductor compound.

[0016] The organic photoelectric conversion element is composed of an active layer (photoelectric conversion layer), a charge (hole, electron) trapping layer, and electrodes (anode, cathode), etc. Among these, the hole trapping layer has the function of extracting the holes generated in the active layer to the electrode, and this can be done effectively by reducing the energy barrier between the active layer and the hole trapping layer.

[0017] Prior art literature

[0018] Patent Literature

[0019] Patent Document 1: Japanese Patent Application Publication No. 2002-83946

[0020] Patent Document 2: Japanese Patent Application Publication No. 2003-234460

[0021] Patent Document 3: Japanese Patent Application Publication No. 2008-258474

[0022] Patent Document 4: Japanese Patent Application Publication No. 2016-178193

[0023] Non-patent literature

[0024] Non-patent document 1: Nature, Vol. 353, 737-740 (1991)

[0025] Non-patent document 2: Appl. Phys. Lett., Vol. 48, 183-185 (1986)

[0026] Non-patent document 3: Scientific Reports, Vol. 5: 7708, 1-7 (2015) Summary of the invention

[0027] Problems to be solved by the invention

[0028] The present invention has been made in view of the above-mentioned actual situation, and an object of the present invention is to provide a charge transporting composition suitable for forming a charge transporting thin film of a photoelectric conversion element, and particularly capable of significantly improving the dark current characteristics of the obtained element when used as a hole trapping layer of a photosensor element.

[0029] Means for solving problems

[0030] The inventors have repeatedly conducted in-depth studies to achieve the above-mentioned purpose, and as a result, found that a charge transport composition comprising a charge transport substance and an organic solvent, wherein the charge transport substance comprises a polyimide polymer obtained by using a diamine component having a specific structure, is suitable for forming a charge transport thin film in an organic photoelectric conversion element, and in particular, when used as a hole trapping layer of a photosensor element, the dark current characteristics of the obtained element can be greatly improved, and the present invention has been completed. Based on this discovery, the present invention has the following as its main purpose.

[0031] That is, the present invention provides the following charge transporting composition.

[0032] 1. A charge transport composition for forming a charge transport thin film in an organic photoelectric conversion element, comprising a charge transport substance and an organic solvent, wherein the charge transport substance comprises: a polyimide-based polymer selected from at least one of a polyimide precursor obtained from a diamine component having a structure of the following formula (1) or (2) and a tetracarboxylic acid component, an ester of a polyimide precursor, and an imide compound of the polyimide precursor,

[0033] [Chemistry 1]

[0034]

[0035] In the formula, R 1represents a hydrogen atom or a monovalent organic group, and * represents a site bonded to another group. Any hydrogen atom constituting the benzene ring may be substituted with a monovalent organic group.

[0036] 2. The charge transport composition according to 1, wherein R 1 It is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a fluoroalkyl group having 1 to 5 carbon atoms, or a tert-butoxycarbonyl group.

[0037] 3. The charge transporting composition according to 1 or 2, further comprising another charge transporting substance other than the polyimide polymer.

[0038] 4. The charge transport composition according to 3, wherein the other charge transport substance is at least one selected from a polythiophene derivative and a polyaniline derivative.

[0039] 5. The charge transport composition according to 4, wherein the other charge transport material is at least one selected from a polythiophene derivative containing a repeating unit represented by the following formula (3) and a polyaniline derivative containing a repeating unit represented by the following formula (4),

[0040] [Chemistry 2]

[0041]

[0042] In the formula, R 1t and R 2t each independently represents a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, -O-[ZO] p -R e , sulfonic acid group, sulfonate group or sulfonate group, or R 2 and R 3 -OYO-, Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and may be substituted with a sulfonic acid group, a sulfonate group, or a sulfonate group, Z is an alkylene group having 1 to 40 carbon atoms which may be substituted with a halogen atom, p is an integer greater than 1, R e is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms,

[0043] R 3t ~R 6t Each of them is independently a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonate group or a sulfonate ester group.

[0044] 6. The charge transporting composition according to any one of 1 to 5, which is used for a hole trapping layer of an organic photoelectric conversion element.

[0045] 7. The charge transport composition according to 6, wherein the organic photoelectric conversion element is an organic thin-film solar cell, a perovskite solar cell, a dye-sensitized solar cell or a photosensor.

[0046] 8. A charge-transporting thin film obtained from the charge-transporting composition according to any one of 1 to 7.

[0047] 9. The charge transport thin film according to 8, wherein the charge transport thin film is a hole trapping layer of an organic photoelectric conversion element.

[0048] 10. An organic photoelectric conversion element comprising the charge transport thin film according to 8 or 9.

[0049] 11. The organic photoelectric conversion element according to 10, wherein the organic photoelectric conversion element is an organic thin-film solar cell, a perovskite solar cell, a dye-sensitized solar cell or a photosensor.

[0050] Effects of the Invention

[0051] By using the charge transport composition of the present invention in an organic photoelectric conversion element, the dark current characteristics of the obtained element can be greatly improved, light leakage from adjacent pixels, etc. can be suppressed, and a light sensor element with an excellent S / N ratio can be provided. That is, according to the charge transport composition and the optical imaging element of the present invention, in response to the recent demand for high performance of optical imaging elements, an optical organic imaging element that is less likely to produce afterimages and can produce beautiful images can be provided. DETAILED DESCRIPTION

[0052] The present invention is described in more detail below.

[0053] The charge transport composition of the present invention is a charge transport composition for forming a charge transport film in an organic photoelectric conversion element, characterized in that it contains a charge transport substance and an organic solvent, wherein the charge transport substance contains at least one polyimide-based polymer selected from a polyimide precursor obtained from a diamine component having a structure of the following formula (1) or (2) and a tetracarboxylic acid component, an ester of the polyimide precursor, and an imide compound of the polyimide precursor.

[0054] [Chemistry 3]

[0055]

[0056] (Where R 1represents a hydrogen atom or a monovalent organic group. * represents a site bonded to an amino group or other groups. Any hydrogen atom forming a benzene ring may be substituted with a monovalent organic group.

[0057] Hereinafter, the diamine having the structure of Formula (1) or (2) may be referred to as a “specific diamine.” In addition, a polymer containing the specific diamine of the present invention may be referred to as a “specific polymer.”

[0058] <Specific diamine>

[0059] The specific diamine has a structure represented by the following formula (1) or (2).

[0060] [Chemistry 4]

[0061]

[0062] In the formula (1) or (2), R 1 represents a hydrogen atom or a monovalent organic group. * represents a site bonded to an amino group or other groups. Any hydrogen atom forming the benzene ring may be substituted with a monovalent organic group. Examples of the monovalent organic group include an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, a fluoroalkenyl group having 2 to 10 carbon atoms, a fluoroalkoxy group having 1 to 10 carbon atoms, and a tert-butoxycarbonyl group.

[0063] Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl and n-decyl.

[0064] Examples of the alkenyl group having 2 to 10 carbon atoms include vinyl, n-1-propenyl, n-2-propenyl, 1-methylvinyl, n-1-butenyl, n-2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1-pentenyl, and n-1-decenyl.

[0065] Examples of the alkoxy group having 1 to 10 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy and n-decyloxy.

[0066] The fluoroalkyl group having 1 to 10 carbon atoms is not particularly limited as long as it is an alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom on the carbon atom is substituted by a fluorine atom. Specific examples thereof include fluoromethyl, difluoromethyl, perfluoromethyl, 1-fluoroethyl, 2-fluoroethyl, 1,2-difluoroethyl, 1,1-difluoroethyl, 2,2-difluoroethyl, 1,1,2-trifluoroethyl, 1,2,2-trifluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, 1,2,2,2-tetrafluoroethyl, perfluoroethyl, 1-fluoropropyl, 2-fluoropropyl, 3-fluoropropyl, 1,1-difluoropropyl, 1,2-difluoropropyl, 1,3-difluoropropyl, 2,2-difluoropropyl, 2,3-difluoropropyl, 3,3-difluoropropyl, 1 , 1,2-trifluoropropyl, 1,1,3-trifluoropropyl, 1,2,3-trifluoropropyl, 1,3,3-trifluoropropyl, 2,2,3-trifluoropropyl, 2,3,3-trifluoropropyl, 3,3,3-trifluoropropyl, 1,1,2,2-tetrafluoropropyl, 1,1,2,3-tetrafluoropropyl, 1,2,2,3-tetrafluoropropyl, 1,3,3,3-tetrafluoropropyl, 2, 2,3,3-tetrafluoropropyl, 2,3,3,3-tetrafluoropropyl, 1,1,2,2,3-pentafluoropropyl, 1,2,2,3,3-pentafluoropropyl, 1,1,3,3,3-pentafluoropropyl, 1,2,3,3,3-pentafluoropropyl, 2,2,3,3,3-pentafluoropropyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl, perfluorooctyl and the like.

[0067] The fluoroalkenyl group having 2 to 10 carbon atoms is not particularly limited as long as it is a fluoroalkenyl group having 2 to 10 carbon atoms in which at least one hydrogen atom on the carbon atom is substituted by a fluorine atom. Specific examples thereof include 2-fluorovinyl, 2,2-difluorovinyl, 2-fluoro-2-propenyl, 3,3-difluoro-2-propenyl, 2,3-difluoro-2-propenyl, 3,3-difluoro-2-methyl-2-propenyl, 3-fluoro-2-butenyl, perfluorovinyl, perfluoropropenyl, and perfluorobutenyl.

[0068] The fluoroalkoxy group having 1 to 10 carbon atoms is not particularly limited as long as it is an alkoxy group having 1 to 10 carbon atoms in which at least one hydrogen atom on the carbon atom is substituted by a fluorine atom. Specific examples thereof include fluoromethoxy, difluoromethoxy, perfluoromethoxy, 1-fluoroethoxy, 2-fluoroethoxy, 1,2-difluoroethoxy, 1,1-difluoroethoxy, 2,2-difluoroethoxy, 1,1,2-trifluoroethoxy, 1,2,2-trifluoroethoxy, 2,2,2-trifluoroethoxy, 1,1,2,2-tetrafluoroethoxy, 1,2,2,2-tetrafluoroethoxy, perfluoroethoxy, 1-fluoropropoxy, 2-fluoropropoxy, 3-fluoropropoxy, 1,1-difluoropropoxy, 1,2-difluoropropoxy, 1,3-difluoropropoxy, 2,2-difluoropropoxy, 2,3-difluoropropoxy, propoxy, 3,3-difluoropropoxy, 1,1,2-trifluoropropoxy, 1,1,3-trifluoropropoxy, 1,2,3-trifluoropropoxy, 1,3,3-trifluoropropoxy, 2,2,3-trifluoropropoxy, 2,3,3-trifluoropropoxy, 3,3,3-trifluoropropoxy, 1,1,2,2-tetrafluoropropoxy, 1,1,2,3-tetrafluoropropoxy, 1,2,2,3- Tetrafluoropropoxy, 1,3,3,3-tetrafluoropropoxy, 2,2,3,3-tetrafluoropropoxy, 2,3,3,3-tetrafluoropropoxy, 1,1,2,2,3-pentafluoropropoxy, 1,2,2,3,3-pentafluoropropoxy, 1,1,3,3,3-pentafluoropropoxy, 1,2,3,3,3-pentafluoropropoxy, 2,2,3,3,3-pentafluoropropoxy, perfluoropropoxy and the like.

[0069] As the R 1 , preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, a fluoroalkenyl group having 2 to 3 carbon atoms, a fluoroalkoxy group having 1 to 3 carbon atoms, and a tert-butoxycarbonyl group, more preferably a hydrogen atom and an alkyl group having 1 to 3 carbon atoms, and still more preferably a hydrogen atom and a methyl group.

[0070] In the structure of the formula (1), the bonding position of the benzene ring to the pyrrole ring is preferably a carbon atom located at an ortho position to the nitrogen atom on the pyrrole ring as shown in the following formula (1-1) from the viewpoint of charge transport properties.

[0071] [Chemistry 5]

[0072]

[0073] Preferred examples of the diamine having the structure of the above formula (1) include diamines represented by the following formula (1-2).

[0074] [Chemistry 6]

[0075]

[0076] In the formula (1-2), R 1 Same as the case of formula (1). 2 Each of them independently represents a single bond or a structure of the following formula (1-3). As in the case of formula (1), any hydrogen atom constituting the benzene ring may be substituted with a monovalent organic group.

[0077] [Chemistry 7]

[0078]

[0079] In formula (1-3), R 3 represents a single bond, selected from -O-, -COO-, -OCO-, -(CH 2 ) i -、-O(CH 2 ) j O-, -CONH-, -NHCO-, -CON(CH 3 )-、-N(CH 3 )CO- and -NR 1 - is a divalent organic group. wherein i represents an integer of 1 to 14, and j represents an integer of 1 to 14. 1 The same as in the case of formula (1). Among these, from the viewpoint of charge transport, R 3 Preferred are single bonds, -O-, -COO-, -OCO-, -CONH-, -NHCO- and -N(CH 3 )-.in addition,* 1 It represents the site bonded to the benzene ring in formula (2). 2 It represents a site bonded to the amino group in formula (1-2). n in formula (1-2) is an integer of 1 to 3, and is preferably 1 or 2.

[0080] Specific examples of the formula (1-2) include substances represented by the following formulae (1-2-1) to (1-2-17), but are not limited to these. Among these, from the viewpoint of charge transport properties, preferred are formula (1-2-1), formula (1-2-2), formula (1-2-3), formula (1-2-5), formula (1-2-8), formula (1-2-9), formula (1-2-10), formula (1-2-11), formula (1-2-12), formula (1-2-13), formula (1-2-14), formula (1-2-15), formula (1-2-16) and formula (1-2-17), and more preferred are formula (1-2-1), formula (1-2-2), formula (1-2-3), formula (1-2-11), formula (1-2-12), formula (1-2-13), formula (1-2-14), formula (1-2-15), formula (1-2-16) and formula (1-2-17). In addition, in the following formulae (1-2-6) and (1-2-7), x1 is an integer of 1 to 14. In addition, Boc represents a tert-butoxycarbonyl group.

[0081] [Chemistry 8]

[0082]

[0083] In the above formula (2), the bonding position to the amino group or other groups of the carbazole ring is preferably as in formula (2-1) from the viewpoint of steric hindrance.

[0084] [Chemistry 9]

[0085]

[0086] In the formula (2-1), R 1 Defined as above.

[0087] Examples of the specific diamine include diamines represented by the following formulae (2-2) to (2-7). In particular, from the viewpoint of charge transport properties, diamines represented by formulae (2-3) to (2-7) are preferred, and diamines represented by formulae (2-4) to (2-7) are more preferred.

[0088] [Chemistry 10]

[0089]

[0090] In the formula, R 1 The definition of is the same as that of formula (1), R 4 are independently a hydrogen atom or a monovalent organic group, R 5 Each of n1 and n2 independently represents a single bond or a divalent organic group. Each of n1 and n3 independently represents 2 or 3. Any hydrogen atom of the benzene ring may be substituted with a monovalent organic group.

[0091] As the R 4 The monovalent organic group in the formula (a) may be any of the above R 1 As R 4 , preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, a fluoroalkenyl group having 2 to 3 carbon atoms, a fluoroalkoxy group having 1 to 3 carbon atoms, and a tert-butoxycarbonyl group, more preferably a hydrogen atom and an alkyl group having 1 to 3 carbon atoms, and still more preferably a hydrogen atom and a methyl group.

[0092] As R 5 The divalent organic group in includes a group having a structure of the following formula (2-8).

[0093] [Chemistry 11]

[0094]

[0095] In the formula, R 6 represents a single bond, selected from -O-, -COO-, -OCO-, -(CH 2 ) r -、-O(CH 2 ) s In the divalent organic group of O-, -NR-, -CONR- and -NRCO-, k represents an integer of 1 to 5. R represents hydrogen or a monovalent organic group, r represents an integer of 1 to 5, and s represents an integer of 1 to 5. The monovalent organic group is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group. 3 represents the site bonded to the benzene ring in formulae (2-5) to (2-7), * 4 It represents the site bonded to the amino group in formulae (2-5) to (2-7).

[0096] As specific examples of specific diamines, diamines represented by the following formulas (2-1-1) to (2-1-19) can be cited, but are not limited to these. Among these, from the perspective of charge transport properties, formulas (2-1-1) to (2-1-7), (2-1-10) to (2-1-17) are preferred, and (2-1-1) to (2-1-7), (2-1-15) to (2-1-17) are more preferred. In the following formula, x2 is an integer of 1 to 14.

[0097] [Chemistry 12]

[0098]

[0099] [Chemistry 13]

[0100]

[0101] <Method for synthesizing specific diamine>

[0102] The synthesis method of the specific diamine can adopt a known method and is not particularly limited. For example, it can be synthesized by the method described in International Publication No. 2018 / 062197, International Publication No. 2018 / 110354, etc.

[0103] <Other diamines: diamines other than those mentioned above>

[0104] The diamine component for obtaining the specific polymer may contain other diamine components other than the specific diamine. Examples of other diamine components include diamines represented by the following formula [2].

[0105] [Chemistry 14]

[0106]

[0107] In the formula [2], A 1 and A 2 independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms, and Y 1 It represents a divalent organic group.

[0108] Examples of the alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, and n-pentyl group.

[0109] Examples of the alkenyl group having 2 to 5 carbon atoms include vinyl, n-1-propenyl, n-2-propenyl, 1-methylvinyl, n-1-butenyl, n-2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl and n-1-pentenyl.

[0110] Examples of the alkynyl group having 2 to 5 carbon atoms include ethynyl, n-1-propynyl, n-2-propynyl, n-1-butynyl, n-2-butynyl, n-3-butynyl, 1-methyl-2-propynyl, n-1-pentynyl, n-2-pentynyl, n-3-pentynyl, n-4-pentynyl, 1-methyl-n-butynyl, 2-methyl-n-butynyl, 3-methyl-n-butynyl, and 1,1-dimethyl-n-propynyl.

[0111] Among these, A 1 and A 2 A hydrogen atom or a methyl group is preferred.

[0112] As Y1 , groups represented by the following formulae (Y-1) to (Y-170) can be cited. It should be noted that in the following formulae, x3 is an integer of 1 to 14, and in the case of having a preferred range, the range is noted. In addition, in the case where there is no description of the range of x3, an integer of 1 to 6 is preferred. In addition, in the following formulae, Me represents a methyl group.

[0113] [Chemistry 15]

[0114]

[0115] [Chemistry 16]

[0116]

[0117] [Chemistry 17]

[0118]

[0119] [Chemistry 18]

[0120]

[0121] [Chemistry 19]

[0122]

[0123] [Chemistry 20]

[0124]

[0125] [Chemistry 21]

[0126]

[0127] [Chemistry 22]

[0128]

[0129] [Chemistry 23]

[0130]

[0131] [Chemistry 24]

[0132]

[0133] [Chemistry 25]

[0134]

[0135] [Chemistry 26]

[0136]

[0137] [Chemistry 27]

[0138]

[0139] [Chemistry 28]

[0140]

[0141] [Chemistry 29]

[0142]

[0143] [Chemistry 30]

[0144]

[0145] [Chemistry 31]

[0146]

[0147] [Chemistry 32]

[0148]

[0149] [Chemistry 33]

[0150]

[0151] [Chemistry 34]

[0152]

[0153] [Chemistry 35]

[0154]

[0155] [Chemistry 36]

[0156]

[0157] In the above formula, Boc represents a tert-butoxycarbonyl group.

[0158] The other diamines described above may be used alone or in combination of two or more. When the diamine component contains other diamines, the content of the specific diamine in the diamine component may be preferably 10 to 100 mol %, more preferably 30 to 100 mol %, and further preferably 50 to 100 mol %.

[0159] <Tetracarboxylic acid component>

[0160] Examples of the tetracarboxylic acid component for obtaining the specific polymer include tetracarboxylic acid, tetracarboxylic dianhydride, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, and tetracarboxylic acid dialkyl ester dihalide. In the present invention, these are also collectively referred to as a tetracarboxylic acid component.

[0161] As the tetracarboxylic acid component, tetracarboxylic dianhydride, a derivative thereof, tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, and tetracarboxylic acid dialkyl ester dihalide (these are collectively referred to as a first tetracarboxylic acid component) can also be used.

[0162] Examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, etc. Specific examples thereof include the following groups [1] to [5], etc.

[0163] [1] Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and the like.

[0164] [2] Examples of the alicyclic tetracarboxylic dianhydride include acid dianhydrides represented by the following formulae (X1-1) to (X1-13).

[0165] [Chemistry 37]

[0166]

[0167] [Chemistry 38]

[0168]

[0169] In the formulas (X1-1) to (X1-4), R 1a ~R 21a R independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms and containing a fluorine atom, or a phenyl group. M represents a hydrogen atom or a methyl group. a It represents a tetravalent organic group represented by the following formulae (Xa-1) to (Xa-7).

[0170] [Chemistry 39]

[0171]

[0172] [3] Examples include 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, and 4,9-dioxatricyclo[5.3.1.02,6]undecane-3,5,8,10-tetraone.

[0173] [4] Examples of the aromatic tetracarboxylic dianhydride include pyromellitic anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and acid dianhydrides represented by the following formulae (X2-1) to (X2-10).

[0174] [Chemistry 40]

[0175]

[0176] [5] Examples include acid dianhydrides represented by the following formulae (X3-1) to (X3-9), and tetracarboxylic dianhydride described in JP-A-2010-97188.

[0177] [Chemistry 42]

[0178]

[0179] The tetracarboxylic acid components described above may be used alone or in combination of two or more. Depending on the properties required of the organic photosensor element or the charge transport layer, one may be used alone or in combination of two or more. When two or more are used in combination, the ratio thereof may be appropriately adjusted.

[0180] <Method for producing specific polymer>

[0181] The specific polymer is obtained by reacting a diamine component and a tetracarboxylic acid component as described above. As the method, for example, a method of reacting a diamine component containing one or more diamines with at least one tetracarboxylic acid component selected from tetracarboxylic dianhydride and its tetracarboxylic acid derivatives to obtain polyamic acid can be cited. Specifically, a method of polyamic acid is obtained by polycondensing a primary diamine or a secondary diamine with tetracarboxylic dianhydride.

[0182] In order to obtain polyamic acid alkyl ester, a method of polycondensing a tetracarboxylic acid having a dialkyl esterified carboxylic acid group with a primary diamine or a secondary diamine, a method of polycondensing a tetracarboxylic acid dihalide having a halogenated carboxylic acid group with a primary diamine or a secondary diamine, or a method of converting the carboxyl group of polyamic acid into an ester is used. When obtaining polyimide, a method of ring-closing the polyamic acid or polyamic acid alkyl ester to obtain polyimide is used.

[0183] The reaction of the diamine component and the tetracarboxylic acid component is usually carried out in a solvent. The solvent used at this time is not particularly limited as long as the generated polyimide precursor is dissolved. Examples of the solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, 3-methoxy-N,N-dimethylpropionamide, dimethyl sulfoxide or 1,3-dimethyl-imidazolidinone. In addition, when the solvent solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone or solvents represented by the following formulas [D-1] to [D-3] can also be used.

[0184] [Chemistry 44]

[0185]

[0186] In formula [D-1], D 1 represents an alkyl group having 1 to 3 carbon atoms. 2 represents an alkyl group having 1 to 3 carbon atoms. 3 It represents an alkyl group having 1 to 4 carbon atoms.

[0187] Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Examples of the alkyl group having 1 to 3 carbon atoms include alkyl groups having 1 to 3 carbon atoms among the above alkyl groups having 1 to 4 carbon atoms.

[0188] These solvents can be used alone or in combination. Even if it is a solvent that does not dissolve the polyimide precursor, as long as the generated polyimide precursor is not precipitated, it can also be mixed in the solvent. In addition, the moisture in the solvent becomes a cause of hindering the polymerization reaction and then hydrolyzing the generated polyimide precursor, so the solvent is preferably a dehydrated solvent.

[0189] When the diamine component and the tetracarboxylic acid component are reacted in a solvent, a solution in which the diamine component is dispersed or dissolved in the solvent by stirring, a method in which the tetracarboxylic acid component is directly added or dispersed or dissolved in the solvent and added; on the contrary, a method in which the diamine component is added to a solution in which the tetracarboxylic acid component is dispersed or dissolved in the solvent; a method in which the diamine component and the tetracarboxylic acid component are alternately added, etc., and any of these methods can be used. In addition, when a plurality of diamine components or tetracarboxylic acid components are used for the reaction, they can be reacted in a premixed state, or they can be reacted separately in sequence, and further, the low molecular weight bodies reacted separately can be mixed and reacted to form a polymer.

[0190] As for the temperature for polycondensing the diamine component and the tetracarboxylic acid component, any temperature of -20 to 150°C can be selected, preferably in the range of -5 to 100°C. The reaction can be carried out at any concentration, but if the concentration is too low, it is difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution is excessively increased, and uniform stirring becomes difficult. Therefore, it is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass. It is also possible to carry out the reaction at a high concentration in the early stage and then add a solvent.

[0191] In the polymerization reaction of the polyimide precursor, the ratio of the total molar number of the diamine component to the total molar number of the tetracarboxylic acid component is preferably 0.8 to 1.2. As in a normal polycondensation reaction, the closer this molar ratio is to 1.0, the greater the molecular weight of the generated polyimide precursor.

[0192] The polyimide is a polyimide obtained by ring-closing the polyimide precursor. In the polyimide, the ring-closing rate (also referred to as the imidization rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted according to the application and purpose. As a method for imidizing the polyimide precursor, thermal imidization by directly heating a solution of the polyimide precursor or catalytic imidization by adding a catalyst to the solution of the polyimide precursor can be cited.

[0193] The temperature for thermal imidization of the polyimide precursor in the solution is 100 to 400° C., preferably 120 to 250° C., and the method is preferably carried out while removing water generated by the imidization reaction to the outside of the system. The catalytic imidization of the polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to the solution of the polyimide precursor and stirring at -20 to 250° C., preferably 0 to 180° C.

[0194] The amount of the basic catalyst is 0.5 to 30 times the mole of the amic acid group, preferably 2 to 20 times the mole, and the amount of the acid anhydride is 1 to 50 times the mole of the amic acid group, preferably 3 to 30 times the mole. As the basic catalyst, pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. can be listed. Among them, pyridine is preferred because it has a moderate alkalinity for the reaction. As the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. can be listed. In particular, if acetic anhydride is used, the purification after the reaction becomes easy, so it is preferred. The imidization rate using catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0195] When the generated polyimide precursor or polyimide is recovered from the reaction solution of the polyimide precursor or polyimide, it is sufficient to put the reaction solution into a solvent and precipitate it. As the solvent used for precipitation, methanol, ethanol, isopropanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, water, etc. can be listed. As for the polymer precipitated by putting into the solvent, after filtering and recovering, it can be dried under normal pressure or reduced pressure, or at room temperature or heating. In addition, if the operation of re-dissolving the polymer recovered by precipitation in the solvent and re-precipitating and recovering is repeated 2 to 10 times, the impurities in the polymer can be reduced. As the solvent at this time, for example, alcohols, ketones, hydrocarbons, etc. can be listed. If more than 3 solvents selected from these are used, the efficiency of purification is further improved, so it is preferred.

[0196] More specific examples of the method for producing the polyamic acid alkyl ester of the present invention are shown in the following (1) to (3), respectively.

[0197] (1) Method for producing by esterification reaction of polyamic acid

[0198] This method is, for example, a method of producing polyamic acid from a diamine component and a tetracarboxylic acid component, and then chemically reacting the diamine component with a carboxyl group (COOH group), i.e., an esterification reaction, to produce a polyamic acid alkyl ester. The esterification reaction is a method of reacting a polyamic acid with an esterifying agent in the presence of a solvent at -20 to 150° C. (preferably 0 to 50° C.) for 30 minutes to 24 hours (preferably 1 to 4 hours).

[0199] As the esterifying agent, an esterifying agent that can be easily removed after the esterification reaction is preferred, and examples thereof include N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, N,N-dimethylformamide dipropyl acetal, N,N-dimethylformamide dineopentyl butyl acetal, N,N-dimethylformamide di-tert-butyl acetal, 1-methyl-3-p-tolyl triazene, 1-ethyl-3-p-tolyl triazene, 1-propyl-3-p-tolyl triazene, 4-(4,6-dimethoxy-1,3,5-triazine-2-yl)-4-methylmorpholinium chloride, etc. The amount of the esterifying agent used is preferably 2 to 6 molar equivalents relative to 1 mole of the repeating unit of the polyamic acid. Among them, 2 to 4 molar equivalents are preferred.

[0200] As the solvent for the esterification reaction, from the aspect of the solubility of polyamic acid in the solvent, the solvent used in the reaction of the diamine component and the tetracarboxylic acid component can be cited. Among them, preferably N, N-dimethylformamide, N, N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, 3-methoxy-N, N-dimethylpropionamide or γ-butyrolactone. These solvents can be used alone or in combination of two or more. With regard to the concentration of the polyamic acid in the solvent in the esterification reaction, from the aspect of the precipitation of polyamic acid that is not easy to occur, preferably 1 to 30 mass %. Particularly preferably 5 to 20 mass %.

[0201] (2) Method for producing by reaction of a diamine component with a tetracarboxylic acid diester dichloride

[0202] This method is, for example, a method of reacting a diamine component with a tetracarboxylic acid diester dichloride in the presence of a base and a solvent at -20 to 150°C (preferably 0 to 50°C) for 30 minutes to 24 hours (preferably 1 to 4 hours). As for the base, pyridine, triethylamine, 4-dimethylaminopyridine, etc. can be used. Among them, pyridine is preferred in order to allow the reaction to proceed gently. The amount of the base used is preferably an amount that can be easily removed after the reaction, preferably 2 to 4 times the mole, more preferably 2 to 3 times the mole relative to the tetracarboxylic acid diester dichloride.

[0203] As solvent, from the aspect of the solubility of the obtained polymer, i.e., polyamic acid alkyl ester in solvent, the solvent used in the reaction of the diamine component and the tetracarboxylic acid component can be listed. Among them, preferably N, N-dimethylformamide, N, N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, 3-methoxy-N, N-dimethylpropionamide or gamma-butyrolactone. These solvents can be used alone or in combination of two or more.

[0204] The concentration of the polyamic acid alkyl ester in the solvent during the reaction is preferably 1 to 30% by mass from the aspect of the precipitation of the polyamic acid alkyl ester. Among them, preferably 5 to 20% by mass. In addition, in order to prevent the hydrolysis of the tetracarboxylic acid diester dichloride, it is preferred that the solvent used for the production of the polyamic acid alkyl ester is dehydrated as much as possible. Furthermore, the reaction is preferably carried out in a nitrogen atmosphere to prevent the mixing of external air.

[0205] (3) Method for producing by reaction of a diamine component with a tetracarboxylic acid diester

[0206] This method is, for example, a method of subjecting a diamine component and a tetracarboxylic acid diester to polycondensation reaction in the presence of a condensing agent, a base and a solvent at 0 to 150° C. (preferably 0 to 100° C.) for 30 minutes to 24 hours (preferably 3 to 15 hours).

[0207] As the condensing agent, triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonic acid diphenyl ester, etc. can be used. The amount of the condensing agent used is preferably 2 to 3 times the mole, particularly preferably 2 to 2.5 times the mole, relative to the tetracarboxylic acid diester.

[0208] As the base, tertiary amines such as pyridine and triethylamine can be used. The amount of the base used is preferably an amount that can be easily removed after the polycondensation reaction, preferably 2 to 4 times the mole, more preferably 2 to 3 times the mole relative to the diamine component. As for the solvent used in the polycondensation reaction, from the aspect of the solubility of the obtained polymer, i.e., the polyamic acid alkyl ester in the solvent, the solvent used in the reaction of the diamine component and the tetracarboxylic acid component can be listed. Among them, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone is preferred. These solvents can be used alone or in combination of two or more.

[0209] In addition, in the polycondensation reaction, the reaction is efficiently carried out by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferred. The amount of the Lewis acid used is preferably 0.1 to 10 times the mole of the diamine component. Among them, 2.0 to 3.0 times the mole is preferred.

[0210] When the polyamic acid alkyl ester is recovered from the solution of the polyamic acid alkyl ester obtained by the methods (1) to (3), the reaction solution can be put into a solvent to precipitate it. Examples of the solvent used for precipitation include water, methanol, ethanol, 2-propanol, hexane, butyl cellosolve, acetone, toluene, and the like. As for the polymer precipitated by putting into a solvent, in order to remove the additives and catalysts used above, it is preferred to perform multiple washing operations with the above solvent. After washing and filtering and recovery, the polymer can be dried under normal pressure or reduced pressure, or at room temperature or by heating. In addition, by repeating the operation of redissolving the polymer recovered by precipitation in a solvent and reprecipitating and recovering it 2 to 10 times, the impurities in the polymer can be reduced. The polyamic acid alkyl ester is preferably manufactured by the method (2) or (3).

[0211] <Other charge transporting substances>

[0212] Furthermore, the charge transporting composition of the present invention may contain a conductive polymer such as polythiophene or polyaniline in order to adjust the charge transporting ability of the charge transporting layer.

[0213] Examples of the conductive polymer such as polythiophene and polyaniline include conductive polymers including a repeating unit represented by the following formula (3) or (4).

[0214] [Chemistry 45]

[0215]

[0216] In the formula, R 1t and R 2t each independently represents a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, -O-[ZO] p -R e , sulfonic acid group, sulfonate group or sulfonate group, or R 2 and R 3 -OYO- formed by the bonding, Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and may be substituted with a sulfonic acid group, a sulfonate group, or a sulfonate group represented by the following formula (S), Z is an alkylene group having 1 to 40 carbon atoms which may be substituted with a halogen atom, p is an integer greater than 1, and R e It is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0217] R 3t ~R 6t Each of them is independently a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonate group or a sulfonate ester group represented by the following formula (S).

[0218] [Chemistry 46]

[0219] -SO 3 M (S)

[0220] (wherein, M represents a hydrogen atom, an alkali metal selected from Li, Na and K, NH(R S ) 3 , an alkyl or fluoroalkyl group having 1 to 5 carbon atoms, or HNC 5 H 5 . R SEach of them independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent.

[0221] In addition, as R S In the case of an alkyl group having a substituent, the substituent includes an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 20 carbon atoms, a hydroxyl group, an amino group, a carboxyl group, and the like.

[0222] Examples of the alkyl group having 1 to 6 carbon atoms include the same groups as exemplified above with respect to the alkyl group.

[0223] Specific examples of the alkoxy group having 1 to 6 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy and the like. Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, tolyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl and the like.

[0224] In particular, as the substituent, a hydroxyl group is preferred, and specific examples of the alkyl group having a hydroxyl group include a 2-hydroxyethyl group, a 3-hydroxypropyl group, a 2-hydroxypropyl group, and a 2,3-dihydroxypropyl group.

[0225] Among these, R S , preferably a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group.

[0226] In the formula (3), R 1t and R 2t Preferably, each independently represents a hydrogen atom, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, -O[C(R a R b )-C(R c R d )-O] p -R e 、-OR f , sulfonic acid group, sulfonate group or sulfonate ester group, or R 1t and R 2t The -OYO- formed by the bonding.

[0227] R a ~R d Each of them independently represents a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0228] Among them, R a ~R dPreferably, they are independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group.

[0229] R e It represents a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0230] Among them, R e A hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group is preferred, and a hydrogen atom, a methyl group, a propyl group, or a butyl group is more preferred.

[0231] In addition, p is preferably 1 to 5, more preferably 1, 2 or 3.

[0232] R f is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a fluoroalkyl group having 1 to 8 carbon atoms, or a phenyl group, and more preferably -CH 2 CF 3 .

[0233] In the present invention, R 1t is preferably a hydrogen atom or a sulfonic acid group or a sulfonate group, more preferably a sulfonic acid group, a sulfonate group or a sulfonate group, and R 2t Preferably, it is an alkoxy group having 1 to 40 carbon atoms or -O-[ZO] p -R e , more preferably -O[C(R a R b )-C(R c R d )-O] p -R e OR f , more preferably -O[C(R a R b )-C(R c R d )-O] p -R e 、-O-CH 2 CH 2 -O-CH 2 CH 2 -O-CH 3 、-O-CH 2 CH 2 -O-CH 2 CH 2 -OH or -O-CH 2 CH 2 -OH, or R 1t and R2t -OYO- formed by mutual bonding.

[0234] For example, the polythiophene derivatives involved in the preferred embodiment of the present invention include R 1t is a sulfonic acid group, a sulfonate group, or a sulfonate ester group, R 2t is a repeating unit of a group other than a sulfonic acid group, a sulfonate group or a sulfonate ester group, or contains a group R 1t and R 2t The repeating unit of -OYO- is formed by bonding.

[0235] Preferably, the polythiophene derivative comprises R 1t is a sulfonic acid group, a sulfonate group or a sulfonate ester group, R 2t is an alkoxy group having 1 to 40 carbon atoms or -O-[ZO] p -R e The repeating unit, or containing R 1t and R 2t The repeating unit of -OYO- is formed by bonding.

[0236] More preferably, the polythiophene derivative comprises R 1t is a sulfonic acid group, a sulfonate group or a sulfonate ester group, R 2t -O[C(R a R b )-C(R c R d )-O] p -R e OR f of repeating units.

[0237] Further preferably, the polythiophene derivative comprises R 1t is a sulfonic acid group, a sulfonate group or a sulfonate ester group, R 2t -O[C(R a R b )-C(R c R d )-O] p -R e The repeating unit, or containing R 1 and R 2 The repeating unit of -OYO- is formed by bonding.

[0238] More preferably, the polythiophene derivative comprises R 1t is a sulfonic acid group, a sulfonate group or a sulfonate ester group, R 2 -O-CH 2 CH 2 -O-CH 2 CH 2 -O-CH3 、-O-CH 2 CH 2 -O-CH 2 CH 2 -OH, or -O-CH 2 CH 2 -OH repeating unit, or containing R 1t and R 2t A repeating unit of a group which is bonded to each other and represented by the following formula (Y1).

[0239] [Chemistry 47]

[0240]

[0241] (Where R y represents an alkyl group having 1 to 6 carbon atoms, or a fluorine atom. M is the same as above.)

[0242] As the above R y The alkyl group having 1 to 6 carbon atoms includes 1t and R 2t The same groups as those exemplified in the description of . An alkyl group having 1 to 3 carbon atoms is preferred, a methyl group and an ethyl group are more preferred, and a methyl group is further preferred.

[0243] As preferred specific examples of the above-mentioned polythiophene derivatives, for example, polythiophene containing at least one repeating unit represented by the following formulae (3-1) to (3-4) can be listed. From the perspective of obtaining particularly good conductivity with good reproducibility and high solubility in solvents, polythiophene containing a repeating unit represented by the following formula (3-4) is more preferred.

[0244] [Chemistry 48]

[0245]

[0246] (Where R y and M are the same as above. )

[0247] In addition, as a preferred structure of the polythiophene derivative, for example, a polythiophene derivative having a structure represented by the following formula (3a) can be cited. In the following formula, the units may be randomly bonded or may be bonded as a block polymer.

[0248] [Chemistry 49]

[0249]

[0250] In the formula, a to d represent the molar ratio of each unit, satisfying 0≤a≤1, 0≤b≤1, 0<a+b≤1, 0≤c<1, 0≤d<1, a+b+c+d=1. M is the same as above.

[0251] Furthermore, the polythiophene derivative may be a homopolymer or a copolymer (including statistical, random, gradient and block copolymers). As a polymer comprising monomer A and monomer B, the block copolymer includes, for example, AB diblock copolymer, ABA triblock copolymer, and (AB) m -Multi-block copolymers. The polythiophene may contain repeating units derived from other types of monomers such as thienothiophene, selenophene, pyrrole, furan, tellurophene, aniline, arylamine, and arylene (such as phenylene, phenylethynyl, and fluorene, etc.).

[0252] In the present invention, the content of the repeating unit represented by formula (3) in the polythiophene derivative is preferably greater than 50 mol%, more preferably greater than 80 mol%, further preferably greater than 90 mol%, further preferably greater than 95 mol%, and most preferably 100 mol%, of all the repeating units contained in the polythiophene derivative.

[0253] In addition, among the repeating units represented by formula (3) in the polythiophene derivative, the content of the repeating units having a sulfonic acid group, a sulfonate group or a sulfonate ester group in the repeating units represented by formula (3) in the polythiophene derivative is preferably 10 mol% or more, more preferably 30 mol% or more, further preferably 50 mol% or more, and further preferably 100 mol%.

[0254] In the present invention, the formed polymer may contain repeating units derived from impurities depending on the purity of the starting monomers used for polymerization. In the present invention, the term "homopolymer" means a polymer containing repeating units derived from one type of monomer, but may also contain repeating units derived from impurities. In the present invention, the polythiophene derivative is preferably a polymer in which substantially all repeating units are repeating units represented by the formula (3), and more preferably a polymer containing at least one of the repeating units represented by the formulas (3-1) to (3-4).

[0255] In the present invention, when the polythiophene derivative contains a repeating unit having a sulfonic acid group, it is preferably an amine adduct in which an amine compound is added to at least a part of the sulfonic acid groups contained in the polythiophene derivative from the viewpoint of further improving solubility and dispersibility in a solvent.

[0256] Examples of the amine compound that can be used to form the amine adduct include monoalkylamine compounds such as methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine; primary amine compounds such as monoarylamine compounds such as aniline and toluidine; N-ethylmethylamine, N-methyl-n-propylamine, N-methyl-isopropylamine, N-methyl-n-butylamine, N-methyl-sec-butylamine, N-methyl-tert-butylamine, N-methyl-isobutylamine, diethylamine, N-ethyl n-propylamine, N-ethylisopropylamine, N-ethyl-n-butylamine, N-ethyl-sec-butylamine, N-ethyl-tert-butylamine, dipropylamine, N-n-propylisopropylamine, N-n-propyl-n-butylamine, N-n-propyl-sec-butylamine, aziridine (ethyleneimine), 2-methylaziridine (propyleneimine), 2,2-dimethylaziridine, azetidine (trimethyleneimine), 2-methylazetidine, pyrrolidine, 2-methylpyrrolidine, 3-methylpyrrolidine, 2,5-dimethylpyrrolidine, piperidine, 2, dialkylamine compounds such as 6-dimethylpiperidine, 3,5-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, hexamethyleneimine, heptamethyleneimine, octamethyleneimine, etc.; secondary amine compounds such as alkylarylamine compounds such as diphenylamine and indoline; N,N-dimethylethylamine, N,N-dimethyl-n-propylamine, N,N-dimethylisopropylamine, N,N-dimethyl-n-butylamine, N,N-dimethyl-sec-butylamine, N,N-dimethyl-tert-butylamine, N,N-dimethylisobutylamine, N, Trialkylamine compounds such as N-diethylmethylamine, N-methyldi(n-propyl)amine, N-methyldiisopropylamine, triethylamine, N,N-diethyl-n-butylamine, N,N-diisopropylethylamine, N,N-di(n-butyl)ethylamine, 1-methylazetidine, 1-methylpyrrolidine, and 1-methylpiperidine are preferably tertiary amine compounds, more preferably trialkylamine compounds, and still more preferably triethylamine, if the balance between the solubility of the amine adduct and the charge transport property of the resulting charge transport film is taken into consideration.

[0257] The amine adduct can be obtained by adding the polythiophene derivative to the amine itself or a solution thereof and stirring the mixture sufficiently.

[0258] In the formula (4), R 3t ~R 6t Each of them is independently a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonate group or a sulfonate ester group.

[0259] Typical examples of the polyaniline represented by the formula (4) include polyanilines containing a structure derived from aniline substituted with a sulfonic acid group or aniline substituted with a carboxyl group.

[0260] Among them, a structure in which an acidic group such as a sulfonic acid group or a carboxyl group is bonded at an ortho position or a meta position with respect to an amino group is preferred from the viewpoints of conductivity, solubility, and the like of the polymer.

[0261] The most representative example of the aniline structure substituted with the sulfonic acid group is aminobenzenesulfonic acid. From the perspective of the conductivity, solubility and other properties of the polymer, preferred are o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid, aniline-2,6-disulfonic acid, aniline-2,5-disulfonic acid, aniline-3,5-disulfonic acid, aniline-2,4-disulfonic acid and aniline-3,4-disulfonic acid.

[0262] Examples of anilines substituted with sulfonic acid groups other than aminobenzenesulfonic acids include alkyl-substituted aminobenzenesulfonic acids such as methylaminobenzenesulfonic acid, ethylaminobenzenesulfonic acid, n-propylaminobenzenesulfonic acid, isopropylaminobenzenesulfonic acid, n-butylaminobenzenesulfonic acid, sec-butylaminobenzenesulfonic acid, and tert-butylaminobenzenesulfonic acid; alkoxy-substituted aminobenzenesulfonic acids such as methoxyaminobenzenesulfonic acid, ethoxyaminobenzenesulfonic acid, and propoxyaminobenzenesulfonic acid; and hydroxy-substituted aminobenzenesulfonic acids.

[0263] Among these, alkyl-substituted aminobenzenesulfonic acids, hydroxy-substituted aminobenzenesulfonic acids, or halogen-substituted aminobenzenesulfonic acids are most preferred in consideration of the conductivity and solubility of the obtained polyaniline. These sulfonic acid group-substituted anilines may contain two or more structures in any ratio.

[0264] The most representative example of the carboxyl-substituted aniline is aminobenzoic acid. From the viewpoint of the conductivity and solubility of the obtained polymer, preferred are o-aminobenzoic acid, m-aminobenzoic acid, p-aminobenzoic acid, aniline-2,6-dicarboxylic acid, aniline-2,5-dicarboxylic acid, aniline-3,5-dicarboxylic acid, aniline-2,4-dicarboxylic acid and aniline-3,4-dicarboxylic acid.

[0265] Examples of carboxyl-substituted anilines other than aminobenzoic acids include alkyl-substituted aminobenzoic acids such as methylaminobenzoic acid, ethylaminobenzoic acid, n-propylaminobenzoic acid, isopropylaminobenzoic acid, n-butylaminobenzoic acid, sec-butylaminobenzoic acid, and tert-butylaminobenzoic acid, alkoxy-substituted aminobenzoic acids such as methoxyaminobenzoic acid, ethoxyaminobenzoic acid, and propoxyaminobenzoic acid, and hydroxy-substituted aminobenzoic acids. Among these, alkyl-substituted aminobenzoic acids or alkoxy-substituted aminobenzoic acids are most preferred from the viewpoint of the conductivity and solubility of the resulting polymer.

[0266] These carboxyl-substituted anilines may be used alone or two or more structures may be contained in any ratio.

[0267] In the case of conductive polymers such as polythiophene and polyaniline, in a part of the repeating units constituting them, their chemical structure sometimes becomes an oxidized structure called a "quinone-type structure". The term "quinone-type structure" is used relative to the term "benzene ring-type structure", so relative to the latter structure containing an aromatic ring, the former means that the double bonds in the aromatic ring move to the outside of the ring (as a result, the aromatic ring disappears) and form a structure with two extracyclic double bonds that are conjugated with other double bonds remaining in the ring. For those skilled in the art, the relationship between these two structures can be easily understood from the relationship between the structures of benzoquinone and hydroquinone. The quinone-type structure of the repeating unit of various conjugated polymers is well known to those skilled in the art. As an example, the quinone-type structure corresponding to the repeating unit of a polythiophene derivative containing a repeating unit represented by the formula (3) is shown in the following formula (3').

[0268] [Chemistry 50]

[0269]

[0270] In formula (3'), R 1t and R 2t As defined in the above formula (3).

[0271] The weight average molecular weight of the conductive polymer such as polythiophene and polyaniline is preferably about 1,000 to 1,000,000, more preferably about 5,000 to 100,000, and even more preferably about 10,000 to 50,000.

[0272] As the conductive polymer containing the repeating unit represented by the formula (3) or (4), a commercially available product may be used, or a polymerized product using a thiophene derivative, an aniline derivative or the like as a starting material by a known method may be used.

[0273] Examples of commercially available products include SELFTRON (registered trademark) manufactured by Tosoh Corporation and aqua-PASS manufactured by Mitsubishi Chemical Corporation.

[0274] <Charge transport composition>

[0275] The charge transport composition of the present invention contains the above-mentioned specific polymer and may contain two or more specific polymers of different structures. In addition, in addition to the specific polymer, other polymers, i.e., polymers not having a divalent group represented by formula (1) or (2) (polymers obtained without a specific diamine represented by formula (1) or (2)) may be contained. As the form of the polymer, polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or its derivative, poly(styrene-phenylmaleimide) derivative, poly(meth)acrylate, etc. can be listed. In the case where the charge transport composition of the present invention contains other polymers, the proportion of the specific polymer relative to the total polymer components is preferably 50% by mass or more, for example, 70 to 99.9% by mass can be listed.

[0276] As for the charge transport composition, from the aspect of forming a uniform film, it generally presents the form of a coating liquid. The charge transport composition of the present invention is also preferably a coating liquid containing the polymer component and an organic solvent that dissolves the polymer component. At this time, the concentration of the polymer in the charge transport composition can be appropriately changed according to the setting of the thickness of the coating to be formed. If the aspect of forming a uniform, defect-free coating, the storage stability of the solution, etc. are considered, it is preferably 1% by mass or more, preferably 10% by mass or less. The concentration of the polymer is particularly preferably 2 to 8% by mass.

[0277] The organic solvent contained in the charge transport composition is not particularly limited as long as it is an organic solvent in which the polymer component is uniformly dissolved. If specific examples are listed, they are N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, N, N-diethylformamide, N, N-diethylformamide, 3-methoxy-N, N-dimethylpropionamide, γ-butyrolactone, 1,3-dimethylimidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, etc. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N, N-dimethylpropionamide, or γ-butyrolactone is preferably used.

[0278] In addition, the organic solvent contained in the charge transport composition of the present invention can also use a solvent that improves the coating properties and surface smoothness of the coating film when the charge transport composition is applied, in addition to the above-mentioned solvents. Specific examples of the organic solvent are listed below, but are not limited to these.

[0279] For example, ethanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentanol, tert-pentanol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 2,6-dimethyl-4-heptanol, 1,2-ethanediol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2-ethyl-1-hexanol, 1-heptanol, 2-heptanol, 3-butylene glycol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 2,6-dimethyl-4-heptanol, 1,2-ethanediol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2 , 3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diisopropyl ether, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 4,6-dimethyl-2-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate , ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2-(methoxymethoxy)ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-(hexyloxy)ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1-(butoxyethoxy)propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether Acid esters, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol acetate monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, and solvents represented by the above formulas [D-1] to [D-3].

[0280] Among them, as for the organic solvent, 1-hexanol, cyclohexanol, 1,2-ethylene glycol, 1,2-propylene glycol, propylene glycol monobutyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether are preferably used. The type and content of such solvents are appropriately selected according to the coating device, coating conditions, coating environment, etc. of the charge transport composition.

[0281] The charge transport composition of the present invention may additionally contain components other than the polymer component and the organic solvent. As such additional components, a close adhesion aid for improving the close adhesion between the charge transport layer and the substrate, a cross-linking agent for improving the strength of the charge transport layer, etc. can be listed. As specific examples of these additional components, poor solvents and cross-linking compounds disclosed in paragraphs

[0104] to

[0116] of International Publication No. 2015 / 060357 can be listed.

[0282] The charge transport composition of the present invention may contain, in addition to the above, polymers other than the specific polymer described in the present invention, a silane coupling agent for the purpose of improving the adhesion between the charge transport layer and the substrate, a cross-linking compound for the purpose of improving the hardness and density of the film when the charge transport layer is formed, and an imidization accelerator for the purpose of efficiently carrying out the imidization reaction caused by heating the polyimide precursor when the coating is fired.

[0283] Examples of compounds that improve the adhesion between the charge transport composition and the substrate include compounds containing functional silanes and compounds containing epoxy groups, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2 -aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl -3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyl trimethoxysilane, N-benzyl-3-aminopropyl triethoxysilane, N-phenyl-3-aminopropyl trimethoxysilane, N-phenyl-3-aminopropyl triethoxysilane, N-bis(oxyethylene)-3-aminopropyl trimethoxysilane, N-bis(oxyethylene)-3-aminopropyl triethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl Oily ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl meta-xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane or N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, etc.

[0284] Furthermore, the following additives may be added to the charge transporting composition of the present invention in order to improve the mechanical strength of the obtained charge transporting thin film.

[0285] [Chemistry 51]

[0286]

[0287] The additive is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the polymer component contained in the charge transport composition. If it is less than 0.1 parts by mass, no effect can be expected, and if it exceeds 30 parts by mass, the charge transport ability may be reduced, so it is more preferably 0.5 to 20 parts by mass.

[0288] Furthermore, in order to improve the stability and uniformity of the charge transporting composition, an amine-based additive described in paragraphs

[0075] to

[0079] of International Publication No. 2008 / 013285 may be added to the charge transporting composition of the present invention.

[0289] The hole trap layer of the present invention can be formed by applying the hole trap layer-forming composition described above to the anode of the photosensor element and firing the composition, but the present invention is not limited to this.

[0290] When coating, the best method can be adopted from various wet methods such as drop casting, spin coating, blade coating, dip coating, roller coating, rod coating, die coating, inkjet, printing (letterpress, gravure, lithography, screen printing, etc.) considering the viscosity and surface tension of the composition, the desired film thickness, etc.

[0291] Usually, coating is performed in an inert gas atmosphere at normal temperature and pressure, or in an air atmosphere (in the presence of oxygen) and may be performed while heating unless the compounds in the composition are decomposed or the composition undergoes a significant change.

[0292] The film thickness is usually about 1 to 300 nm, preferably about 30 to 200 nm. The film thickness can be changed by changing the solid content concentration in the composition or by changing the amount of solution during coating.

[0293] Next, a method for producing a photosensor element using the hole trap layer-forming composition of the present invention will be described.

[0294] [Formation of anode layer]: A process of forming a layer of anode material on the surface of a transparent substrate to produce a transparent electrode.

[0295] As the anode material, metal oxides such as indium tin oxide (ITO) and indium zinc oxide (IZO), and organic compounds with high charge transport properties such as polythiophene derivatives and polyaniline derivatives can be used. In addition, as the transparent substrate, a substrate made of glass or a transparent resin can be used.

[0296] The method for forming the layer of anode material (anode layer) is appropriately selected according to the properties of the anode material, and is generally a dry method (evaporation method) using a sublimable compound or a wet method (especially spin coating or slit coating method) using a varnish containing a charge transporting compound.

[0297] In addition, a commercial product can be preferably used as the transparent electrode. In this case, a substrate subjected to a smoothing treatment is preferably used from the viewpoint of improving the yield of the element. When a commercial product is used, the method for manufacturing an organic thin film solar cell of the present invention does not include a step of forming an anode layer.

[0298] The transparent electrode used is preferably used after cleaning with lotion, alcohol, pure water, etc. For example, for the anode substrate, it is preferred to implement a surface treatment such as UV ozone treatment, oxygen-plasma treatment, etc. before use (in the case where the anode material is organic matter as the main component, surface treatment may not be performed).

[0299] [Formation of hole trapping layer]: Step of forming a hole trapping layer on the anode material layer

[0300] According to the above method, a hole trapping layer is formed on the layer of the anode material using the hole trapping layer-forming composition of the present invention.

[0301] [Formation of Photoelectric Conversion Layer]: Step of forming a photoelectric conversion layer on the hole trapping layer

[0302] The photoelectric conversion layer may be a layer formed by laminating an n-layer which is a thin film containing an n-type semiconductor material and a p-layer which is a thin film containing a p-type semiconductor material, or may be a non-laminated thin film containing a mixture of these materials.

[0303] Examples of n-type semiconductor materials include fullerene, [6,6]-phenyl-C 61 -Methyl butyrate (PC 61 BM), [6,6]-phenyl-C 71 -Methyl butyrate (PC 71 On the other hand, as p-type semiconductor materials, there can be listed stereoregular poly (3-hexylthiophene) (P3HT), PTB7, PDTP-DFBT, polymers containing thienothiophene units described in Japanese Patent Publication No. 2009-158921 and International Publication No. 2010 / 008672, polymers containing a thiophene skeleton in the main chain, phthalocyanines such as CuPC and ZnPC, porphyrins such as tetrabenzoporphyrin, etc.

[0304] Among these, PC is preferred as the n-type material. 61 BM, PC 71 As the p-type material, BM is preferably a polymer including a thiophene skeleton in the main chain, such as PTB7.

[0305] It should be noted that the "thiophene skeleton in the main chain" mentioned here means a divalent aromatic ring containing only thiophene, or a divalent condensed aromatic ring containing one or more thiophenes such as thienothiophene, benzothiophene, dibenzothiophene, benzodithiophene, naphthiophene, naphthiophene dithiophene, anthrathiophene, anthradithiophene, etc., which can be represented by the above R 1 ~R 6 The substituent represented is substituted.

[0306] The method for forming the photoelectric conversion layer is appropriately selected according to the properties of the n-type semiconductor or p-type semiconductor material, and is generally a dry method using a sublimable compound (especially a vapor deposition method) or a wet method using a varnish containing the material (especially a spin coating method or a slit coating method).

[0307] [Chemistry 52]

[0308]

[0309] (In the formula, n1 and n2 represent the number of repeating units and are positive integers.)

[0310] [Formation of electron trap layer]: Step of forming an electron trap layer on the photoelectric conversion layer

[0311] If necessary, an electron trap layer may be formed between the photoelectric conversion layer and the cathode layer.

[0312] Examples of materials for forming the electron trap layer include lithium oxide (Li 2 O), magnesium oxide (MgO), aluminum oxide (Al 2 O 3 ), lithium fluoride (LiF), sodium fluoride (NaF), magnesium fluoride (MgF 2 ), Strontium fluoride (SrF 2 ), cesium carbonate (Cs 2 CO 3 ), 8-hydroxyquinoline lithium salt (Liq), 8-hydroxyquinoline sodium salt (Naq), bathocuproine (BCP), 4,7-diphenyl-1,10-phenanthroline (BPhen), polyethyleneimine (PEI), ethoxylated polyethyleneimine (PEIE), etc.

[0313] The method for forming the electron trap layer is appropriately selected depending on the properties of the material, and generally, a dry method (particularly a vapor deposition method) using a sublimable compound or a wet method (particularly a spin coating method or a slit coating method) using a varnish containing a material is used.

[0314] [Formation of cathode layer]: Step of forming a cathode layer on the electron trap layer

[0315] Examples of the cathode material include aluminum, magnesium-silver alloys, aluminum-lithium alloys, lithium, sodium, potassium, cesium, calcium, barium, silver, and gold. A plurality of cathode materials may be stacked or mixed for use.

[0316] The method for forming the cathode layer is appropriately selected according to the properties of the material thereof, and a dry method (particularly a vapor deposition method) is generally used.

[0317] [Formation of Carrier Blocking Layer]

[0318] If necessary, a carrier blocking layer may be provided between any layers in order to control the rectification property of the photocurrent or the like.

[0319] Examples of the material for forming the carrier blocking layer include titanium oxide and zinc oxide.

[0320] The method for forming the carrier blocking layer is appropriately selected according to the properties of the material. Generally, when a sublimable compound is used, a vapor deposition method is used, and when a varnish in which the material is dissolved is used, either a spin coating method or a slit coating method is used.

[0321] The optical sensor element produced using the method exemplified above can be introduced into a glove box again to prevent degradation of the element due to the atmosphere, and sealed in an atmosphere of an inert gas such as nitrogen. In the sealed state, it can be made to function as an optical sensor element or its characteristics can be measured.

[0322] Sealing methods include a method in which a concave glass substrate having a UV curing resin attached to the end is attached to the film forming surface of an organic thin film solar cell element in an inert gas atmosphere and the resin is cured by UV irradiation; a method in which film sealing is performed by sputtering or the like under vacuum; etc.

[0323] In the above-mentioned [Formation of Photoelectric Conversion Layer], by using an active layer composition containing a perovskite semiconductor compound in the photoelectric conversion layer, a perovskite type solar cell element can be produced.

[0324] The so-called perovskite semiconductor compound refers to a semiconductor compound having a perovskite structure. As the perovskite semiconductor compound, known compounds can be used without particular limitation, for example, compounds represented by the general formula A + M 2+ X - 3 A compound represented by, or, + 2 M 2+ X - 4 A compound represented by + represents a monovalent cation, M 2+represents a divalent cation, X - It represents a monovalent anion.

[0325] As a monovalent cation A + Examples of the cation include cations containing elements of Group 1 and Groups 13 to 16 of the periodic table. Among these, cesium ions, rubidium ions, ammonium ions which may have a substituent, and phosphonium ions which may have a substituent are preferred.

[0326] As the ammonium ion which may have a substituent, for example, a primary ammonium ion or a secondary ammonium ion can be cited. There is no particular limitation on the substituent, but an alkylammonium ion or an arylammonium ion is preferred. In particular, in order to avoid steric hindrance, a monoalkylammonium ion having a three-dimensional crystal structure is more preferred. The number of carbon atoms of the alkyl group contained in the alkylammonium ion is preferably 1 to 30, more preferably 1 to 20, and further preferably 1 to 10. The number of carbon atoms of the aryl group contained in the arylammonium ion is preferably 6 to 30, more preferably 6 to 20, and further preferably 6 to 12.

[0327] As a monovalent cation A + Specific examples include methylammonium ion (MA), ethylammonium ion, isopropylammonium ion, n-propylammonium ion, isobutylammonium ion, n-butylammonium ion, tert-butylammonium ion, dimethylammonium ion, diethylammonium ion, phenylammonium ion, benzylammonium ion, phenethylammonium ion, guanidinium ion, formamidinium ion (FA), acetamidazolium ion and imidazolium ion. The cation A + These can be used alone or in combination of two or more.

[0328] As a divalent cation M 2+ , preferably a divalent metal cation or a semi-metal cation, more preferably a cation of an element of Group 14 of the periodic table. Specific examples of the divalent cation M include lead cations (Pb 2+ ), tin cation (Sn 2+ ), germanium cation (Ge 2+ ) etc. In the present invention, from the viewpoint of obtaining a photoelectric conversion element with excellent stability, it is preferred to contain lead cations. The cation M 2+ These can be used alone or in combination of two or more.

[0329] As a monovalent anion X - , halogen ions, acetate ions, nitrate ions, acetylacetonate ions, thiocyanate ions, and 2,4-pentanedione ions can be cited, and halogen ions are preferred. - These can be used alone or in combination of two or more.

[0330] Examples of the halogen ion include a chloride ion, a bromide ion, and an iodide ion.

[0331] As the perovskite semiconductor compound, for example, an organic-inorganic perovskite semiconductor compound is preferred, and a halide-based organic-inorganic perovskite semiconductor compound is more preferred. Specific examples of the perovskite semiconductor compound include MAPbI 3 MAPbBr 3 MAPbCl 3 、MASnI 3 、MASnBr 3 、MASnCl 3 MAPbI (3-x) Cl x MAPbI (3-x) Br x MAPbBr (3-x) Cl x MAPb (1-y) Sn y I 3 MAPb (1-y) Sn y Br 3 MAPb (1-y) Sn y Cl 3 MAPb (1-y) Sn y I (3-x) Cl x MAPb (1-y) Sn y I (3-x) Br x MAPb (1-y) Sn y Br (3-x) Cl x , FAPbI 3 , FAPbBr 3 ,FAPB (3-x) Br x , F.A. (1-V) MA V PbI (3-x) Br x , Cs (1-W-V) FA w MA V PbI (3-x) Br x In addition, x represents an arbitrary number from 0 to 3, and y represents an arbitrary number from 0 to 1.

[0332] From the viewpoint of improving the photoelectric conversion efficiency, it is preferable to use a semiconductor compound having an energy band gap of 1.0 to 3.5 eV as the perovskite semiconductor compound.

[0333] The active layer may contain two or more perovskite semiconductor compounds. For example, the active layer may contain the A + 、M 2+ and X - At least one of the two or more different perovskite semiconductor compounds.

[0334] The content of the perovskite semiconductor compound in the active layer is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more from the viewpoint of obtaining good photoelectric conversion characteristics. There is no particular restriction on the upper limit, which is usually 100% by mass or less.

[0335] The active layer may contain other additives as necessary, for example, surfactants, charge-imparting agents, 1,8-diiodooctane, N-cyclohexyl-2-pyrrolidone and the like.

[0336] The content of these additives in the active layer is preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less from the viewpoint of obtaining good PCE. The lower limit is not particularly limited, but is usually 0% by mass or more.

[0337] The method for forming the active layer is similar to the above-mentioned method, and the optimum method is adopted from the various wet methods mentioned above in consideration of the viscosity and surface tension of the composition, the required film thickness, and the like.

[0338] Example

[0339] The present invention will be further described below based on examples, but the present invention is not limited to these examples.

[0340] <Synthesis of polyimide precursor>

[0341] The abbreviations used in the preparation of the polyimide precursor described below are as follows.

[0342] (Tetracarboxylic dianhydride)

[0343] BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride

[0344] BPDA: 4,4'-Biphthalic anhydride

[0345] CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

[0346] TCA: 2,3,5-Tricarboxycyclopentylacetic dianhydride

[0347] CBDE: A compound represented by the following structural formula

[0348] [Chemistry 53]

[0349]

[0350] (Diamine)

[0351] Diamine compounds represented by the following formulas DA-1 and DA-2

[0352] [Chemistry 54]

[0353]

[0354] <Solvent>

[0355] NMP: N-methyl-2-pyrrolidone

[0356] NEP: N-ethyl-2-pyrrolidone

[0357] BCS: Butyl Cellosolve

[0358] <Condensation agent>

[0359] DMT-MM: dimethoxy-1,3,5-triazinylmethylmorpholinium

[0360] <Additives>

[0361] 3API: 1-(3-aminopropyl)imidazole

[0362] [Chemistry 55]

[0363]

[0364] <Conductive auxiliary materials>

[0365] SELFTRON S: 2.0 mass % aqueous solution of polythiophene manufactured by Tosoh Corporation

[0366] The conditions for measuring the molecular weight of the polyimide precursor are as follows.

[0367] Equipment: Room-temperature gel permeation chromatography (GPC) equipment (SSC-7200) manufactured by Senshu Scientific Co., Ltd.

[0368] Column: Column manufactured by Shodex (KD-803, KD-805)

[0369] Column temperature: 50°C

[0370] Eluent: N, N'-dimethylformamide (as an additive, lithium bromide monohydrate (LiBr·H 2 O) is 30mmol / L, phosphoric acid-anhydrous crystals (o-phosphoric acid) is 30mmol / L, tetrahydrofuran (THF) is 10ml / L)

[0371] Flow rate: 1.0ml / min

[0372] Standard samples for preparing the calibration curve: TSK standard polyethylene oxide manufactured by Tosoh Corporation (molecular weight of about 9,000,000, 150,000, 100,000, and 30,000), and polyethylene glycol manufactured by Polymer Laboratories (molecular weight of about 12,000, 4,000, and 1,000).

[0373] In addition, the viscosity measurement conditions of the polyimide precursor solution are as follows.

[0374] The viscosity was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) at a sample volume of 1.1 mL, a conical rotor TE-1 (1°34', R24), and a temperature of 25°C.

[0375] [Synthesis example 1]

[0376] BPDA (2.74 g, 9.3 mmol) and DA-1 (4.21 g, 10 mmol) were dissolved in NMP (79.95 g), and the mixture was reacted at 25° C. for 5 hours to obtain a polyamic acid solution (A).

[0377] The viscosity of the obtained polyamic acid solution was 35 mPa·s. The number average molecular weight of the polyamic acid was 7,300 and the weight average molecular weight was 33,200.

[0378] [Synthesis example 2]

[0379] BODA (3.36 g, 13.4 mmol) and DA-2 (6.63 g, 14 mmol) were dissolved in NMP (89.94 g), and the mixture was reacted at 40° C. for 20 hours to obtain a polyamic acid solution (B).

[0380] The viscosity of the obtained polyamic acid solution was 72 mPa·s. The number average molecular weight and weight average molecular weight of the polyamic acid were 9,500 and 42,300, respectively.

[0381] [Synthesis example 3]

[0382] BODA (3.36 g, 13.4 mmol) and DA-1 (6.63 g, 14 mmol) were dissolved in NEP (89.94 g), and the mixture was reacted at 40° C. for 20 hours to obtain a polyamic acid solution (D).

[0383] The viscosity of the obtained polyamic acid solution was 90 mPa·s. The number average molecular weight and weight average molecular weight of the polyamic acid were 8,400 and 22,100, respectively.

[0384] [Synthesis Example 4]

[0385] BODA (3.53 g, 14.1 mmol) and DA-2 (6.32 g, 15 mmol) were dissolved in NEP (88.66 g), and the mixture was reacted at 40° C. for 20 hours to obtain a polyamic acid solution (E).

[0386] The viscosity of the obtained polyamic acid solution was 101 mPa·s. The number average molecular weight and weight average molecular weight of the polyamic acid were 10,100 and 52,200, respectively.

[0387] [Synthesis example 5]

[0388] CBDA (0.94 g, 4.8 mmol) and DA-1 (2.37 g, 5 mmol) were dissolved in NEP (29.78 g), and the mixture was reacted at 5° C. for 5 hours to obtain a polyamic acid solution (F).

[0389] The viscosity of the obtained polyamic acid solution was 328 mPa·s. The number average molecular weight and weight average molecular weight of the polyamic acid were 13,500 and 67,700, respectively.

[0390] [Synthesis example 6]

[0391] CBDA (0.94 g, 4.8 mmol) and DA-2 (2.11 g, 5 mmol) were dissolved in NEP (27.44 g), and the mixture was reacted at 5° C. for 5 hours to obtain a polyamic acid solution (G).

[0392] The viscosity of the obtained polyamic acid solution was 180 mPa·s. The number average molecular weight and weight average molecular weight of the polyamic acid were 11,100 and 38,000, respectively.

[0393] [Synthesis Example 7]

[0394] TCA (3.01 g, 13.4 mmol) and DA-1 (6.63 g, 14 mmol) were dissolved in NEP (86.79 g), and the mixture was reacted at 40° C. for 20 hours to obtain a polyamic acid solution (H).

[0395] The viscosity of the obtained polyamic acid solution was 193 mPa·s. The number average molecular weight and weight average molecular weight of the polyamic acid were 10,500 and 43,900, respectively.

[0396] [Synthesis example 8]

[0397] TCA (3.01 g, 13.4 mmol) and DA-2 (5.90 g, 14 mmol) were dissolved in NMP (80.23 g), and the mixture was reacted at 40° C. for 20 hours to obtain a polyamic acid solution (I).

[0398] The viscosity of the obtained polyamic acid solution was 164 mPa·s. The number average molecular weight and weight average molecular weight of the polyamic acid were 11,800 and 67,900, respectively.

[0399] [Synthesis Example 9]

[0400] CBDE (2.47 g, 9.5 mmol) and DA-1 (4.74 g, 10 mmol) were dissolved in NMP (84.1 g), and triethylamine (0.51 g, 5 mmol) was added as a catalyst, and then DMT-MM (8.3 g, 30 mmol) was added as a condensing agent under ice cooling, and reacted for 20 hours to obtain a polyamic acid ester solution (PAE-1) having a viscosity of 113 mPa·s. This polyamic acid ester solution was purified by reprecipitation with methanol to obtain a polyamic acid ester powder (PAE-P1).

[0401] The number average molecular weight of this polyamic acid ester is 14100, and the weight average molecular weight is 45000.

[0402] [Synthesis Example 10]

[0403] CBDE (2.45 g, 9.4 mmol) and DA-2 (4.22 g, 10 mmol) were dissolved in NMP (76.6 g), and triethylamine (0.51 g, 5 mmol) was added as a catalyst, and DMT-MM (8.30 g, 30 mmol) was added as a condensing agent under ice cooling, and reacted for 20 hours to obtain a polyamic acid ester solution (PAE-2) having a viscosity of 32 mPa·s. This polyamic acid ester solution was reprecipitated and purified with methanol to obtain a polyamic acid ester powder (PAE-P2).

[0404] The number average molecular weight of this polyamic acid ester is 10300, and the weight average molecular weight is 31100.

[0405] <Preparation of Charge Transporting Composition>

[0406] [Example 1-1]

[0407] NMP (8.10 g) and BCS (3.9 g) were added to the polyamic acid solution (A) (7.50 g) obtained in Synthesis Example 1, and 3API (8% by mass aqueous solution) (5.29 g) and water (5.21 g) were slowly added to the solution as additives, and stirred at 25° C. for 1 hour. Then, the mixture was filtered with a syringe filter having a pore size of 0.45 μm to obtain a charge transport composition (A1) having a polyamic acid concentration of 2.0% by mass.

[0408] [Example 1-2]

[0409] SELFTRON S (Tosoh Corporation, 2.0 mass % aqueous solution) (1.0 g) was added to the charge transport composition (A1) (9.0 g) obtained in Example 1, and stirred at 25°C for 1 hour. Then, the mixture was filtered with a syringe filter having a pore size of 0.45 μm to obtain a charge transport composition (A2).

[0410] [Examples 1-3]

[0411] A charge transporting composition (B1) was obtained in the same manner as in Example 1 except that the polyamic acid solution (A) was changed to the polyamic acid solution (B).

[0412] [Examples 1-4]

[0413] A charge transporting composition (B2) was obtained by the same operation as in Example 2 except that the charge transporting composition (A1) was changed to the charge transporting composition (B1).

[0414] [Comparative Example 1-1]

[0415] As a comparative example of a charge transporting composition, a polythiophene aqueous dispersion PEDOT:PSS (CLEVIOS HTL Solar manufactured by Heraeus Corporation) was used as it was.

[0416] Table 1 summarizes the charge transporting compositions obtained above.

[0417] [Table 1]

[0418] Charge transport composition Polyamic acid solution Amount of conductive auxiliary material Example 1-1 A1 A - Example 1-2 A2 A SELFTRON S 10 mass% Examples 1-3 B1 B - Examples 1-4 B2 B SELFTRON S 10 mass% Comparative Example 1-1 PEDOT:PSS - -

[0419] [Examples 1-5]

[0420] NEP (6.0 g) and BCS (2.0 g) were added to the polyamic acid solution (D) (2.0 g) obtained in Synthesis Example 3, and stirred at 25° C. for 1 hour. The mixture was then filtered using a syringe filter having a pore size of 0.45 μm to obtain a charge transporting composition (D1) having a polyamic acid concentration of 2.0 mass %.

[0421] [Examples 1-6 to 1-10]

[0422] Charge transporting compositions (E1) to (I1) having a polyamic acid concentration of 2.0% by mass were obtained by performing the same operation as in Examples 1 to 5 except that the polyamic acid solution (D) was changed to the polyamic acid solution obtained in Synthesis Examples 4 to 8, respectively.

[0423] [Examples 1-11]

[0424] The polyamic acid ester powder (PAE-P1) (0.2 g) obtained in Synthesis Example 9 was redissolved in NEP (7.8 g) at 25° C., diluted with BCS (2.0 g), and stirred at 25° C. for 1 hour to prepare a charge transporting composition (J1) having a polyamic acid ester concentration of 2.0 mass %.

[0425] [Examples 1-12]

[0426] A charge transporting composition (K1) was prepared by the same operation as in Example 1-11 except that the polyamic acid ester powder of Example 1-11 was changed to (PAE-P2).

[0427] Table 2 summarizes the charge transporting compositions obtained above.

[0428] [Table 2]

[0429] Polyimide Precursor Charge transport composition Examples 1-5 Polyamic acid solution (D) D1 Examples 1-6 Polyamic acid solution (E) E1 Examples 1-7 Polyamic acid solution (F) F1 Examples 1-8 Polyamic acid solution (G) G1 Examples 1-9 Polyamic acid solution (H) H1 Examples 1-10 Polyamic acid solution (I) I1 Examples 1-11 Polyamic acid ester (PAE-P1) J1 Examples 1-12 Polyamic acid ester (PAE-P2) K1

[0430] <Fabrication of single-layer components>

[0431] [Example 2-1]

[0432] In order to evaluate the dark current characteristics and carrier mobility of the hole trapping layer, a single-layer device of the hole trapping layer was produced by the following procedure.

[0433] A glass substrate of 25 mm×25 mm was prepared on which a polyimide insulating film was patterned so that the pixel area of ​​ITO became 2 mm×2 mm on an ITO transparent conductive film patterned in stripes of 5 mm×25 mm.

[0434] The hole trapping layer composition A1 prepared in Example 1-1 was applied to the glass substrate by spin coating in air, dried on a 100°C hot plate for 2 minutes, and fired on a 200°C hot plate for 10 minutes to form a hole trapping layer with a thickness of 30 nm.

[0435] Next, the substrate with the hole trapping layer formed thereon was placed in a vacuum deposition apparatus, and the vacuum inside the apparatus was evacuated until the vacuum degree reached 1×10 -3 Pa or less, an aluminum layer was evaporated to a thickness of 80 nm by a resistance heating method, thereby producing a single-layer element (A1-1) in which the area of ​​the intersection of the ITO layer and the aluminum layer was 2 mm×2 mm.

[0436] [Example 2-2]

[0437] A single-film element (A2-1) was prepared in the same manner as in Example 2-1 except that the charge-transporting composition (A1) was replaced by the charge-transporting composition (A2).

[0438] [Example 2-3]

[0439] A single-film element (B2-1) was prepared in the same manner as in Example 3-1 except that the charge-transporting composition (A1) was changed to the charge-transporting composition (B2).

[0440] [Comparative Example 2-1]

[0441] A single-film element (C1-1) was produced in the same manner as in Example 3-1, except that the charge transporting composition (A1) was changed to the charge transporting composition (PEDOT:PSS) and the calcination at 200° C. was not performed.

[0442] <Measurement of current-voltage characteristics, carrier mobility, and conductivity of the hole trap layer>

[0443] The voltage-current characteristic curve of the single-film element prepared in Example 2-1 was measured. The voltage-current characteristic curve was measured using a semiconductor parameter analyzer. During the measurement, the measurement was performed in a table-top manual probe (manufactured by APPOLOWAVE) in a light-shielded state.

[0444] The current value at 1V is calculated from the obtained voltage-current curve as the dark current value, and the dark current value is calculated and divided by 4 mm 2 The obtained value is taken as the current density (mA / cm 2 ).

[0445] From this current density value, the carrier mobility and conductivity were calculated using the Mott-Gurney equation for space charge limited current. (The electrical constant was set to 8.85×10 -12 F / m, the relative dielectric constant of the hole trapping layer is set to 3 for calculation)

[0446] The dark current characteristics, carrier mobility, and electrical conductivity of the single-film devices produced in Examples 2-2 to 2-3 and Comparative Example 2-1 were calculated by the same method.

[0447] Table 3 shows the results.

[0448] [Table 3]

[0449]

[0450] The current-voltage curve was measured using a single-layer element. As a result, it was found that the sequence of current density, carrier mobility, and conductivity of each element was related to the sequence of dark current characteristics in the optical sensor element. In addition, it was found that in the element using PEDOT:PSS in Comparative Example 2-1, the voltage-current curve became a straight line, and an ohmic contact was formed. Therefore, it is believed that Comparative Example 2-1 did not become a space charge limited current, and the actual carrier mobility and conductivity showed higher values.

[0451] From these results, it is considered that in order to reduce the dark current characteristics of the photosensor element, it is effective to suppress the carrier mobility and conductivity of the hole transport material to be low, and the polyimide-based material of the present invention satisfies these properties.

[0452] <Fabrication of optical sensor elements>

[0453] The apparatus used for fabrication and evaluation of the optical sensor element is as follows.

[0454] (1) Glove box: manufactured by Hachiyama Bussan Co., Ltd., VAC glove box system

[0455] (2) Evaporation device: AOYAMA ENGINEERING Co., Ltd. vacuum evaporation device

[0456] (3) Solar simulator: Spectrometer Co., Ltd., OTENTOSUN-III, AM1.5G filter, radiation intensity: 100 mW / cm 2

[0457] (4) Source measurement unit: Keithley Instruments, 2612A

[0458] (5) Semiconductor parameter analyzer: 4156C manufactured by Keysight Technologies

[0459] <Fabrication of optical sensor elements>

[0460] [Example 3-1]

[0461] A 25 mm × 25 mm glass substrate with an ITO transparent conductive layer patterned in a stripe shape of 10 mm × 25 mm, which will become a cathode, was subjected to UV / ozone treatment for 15 minutes. The hole trapping layer composition A1 prepared in Example 1-1 was applied to the substrate by spin coating in the atmosphere, dried on a hot plate at 100° C. for 2 minutes, and then fired on a hot plate at 200° C. for 10 minutes to form a hole trapping layer. The film thickness of the hole trapping layer was about 30 nm.

[0462] Then, in a glove box replaced with nitrogen, an active layer PV-ALT-D1A1 (manufactured by Raynergy tek) was formed on the hole transport layer by spin coating to form an active layer having a thickness of about 100 nm.

[0463] Next, the stacked substrates were placed in a vacuum deposition apparatus and evacuated until the vacuum level in the apparatus reached 1×10 -3Pa, LiQ, which will be the electron trap layer, was evaporated to a thickness of 1 nm by resistance heating. Finally, a silver layer, which will be the anode, was evaporated to a thickness of 100 nm, thereby producing a light sensor element (A1-2) with an area of ​​10 mm×10 mm at the intersection of the strip-shaped ITO layer and the silver layer.

[0464] [Example 3-2]

[0465] A photosensor element (A2-2) was prepared in the same manner as in Example 3-1 except that the charge transporting composition (A1) was changed to the charge transporting composition (A2).

[0466] [Example 3-3]

[0467] A photosensor element (B2-2) was prepared in the same manner as in Example 3-1 except that the charge transporting composition (A1) was changed to the charge transporting composition (B2).

[0468] [Comparative Example 3-1]

[0469] A photosensor element (C1-2) was prepared in the same manner as in Example 3-1, except that the charge transporting composition (A1) was changed to the charge transporting composition (PEDOT:PSS) and the calcination at 200° C. was not performed.

[0470] <Dark current characteristics of optical sensor elements>

[0471] The voltage-current characteristic curve of the optical sensor element prepared in Example 3-1 was measured. The voltage-current characteristic curve was measured using a semiconductor parameter analyzer. During the measurement, the measurement was performed in a table-top manual prober (manufactured by APPOLOWAVE) in a light-shielded state.

[0472] From the obtained voltage-current curve, the current value at 1 V was calculated as the dark current value.

[0473] The dark current characteristics of the optical sensor elements produced in Examples 3-2 and 3-3 and Comparative Example 3-1 were calculated by the same method.

[0474] Table 4 shows the results.

[0475] [Table 4]

[0476]

[0477] From the results in Table 4, it was confirmed that the optical sensor element using the polyimide-based material of the present invention has significantly improved dark current characteristics compared to the optical sensor element of the comparative example.

[0478] <Production of organic thin-film solar cells>

[0479] [Example 4-1]

[0480] A forward stacked solar cell element (A2-3) was prepared in the same manner as in Example 3-1 except that the active layer was changed to PV-F1062 (manufactured by Merck).

[0481] [Example 4-2]

[0482] A forward stacked solar cell element (B2-3) was prepared in the same manner as in Example 4-1 except that the charge transporting composition (A2) was replaced by the charge transporting composition (B2).

[0483] [Comparative Example 4-1]

[0484] A forward stacked solar cell element (C1-3) was prepared in the same manner as in Example 4-1 except that the charge transporting composition (B2) was changed to the charge transporting composition (PEDOT:PSS).

[0485] The forward stacked solar cell element prepared above was used with a light intensity adjusted to 100 mW / cm 2 The solar simulator was used to evaluate the power generation performance. The results are shown in Table 5.

[0486] In addition, the conversion efficiency PCE [%] was calculated using the following formula.

[0487] PCE[%] = Jsc[mA / cm 2 ]×Voc[V]×FF÷incident light intensity(100[mW / cm 2 ])×100

[0488] (Short circuit current density: Jsc[mA / cm 2 ], open end voltage: Voc[V], curve factor: FF)

[0489] [Table 5]

[0490] Example 4-1 Example 3-2 Comparative Example 4-1 Charge transport composition A2 B2 PEDOT:PSS <![CDATA[Jsc〔mA / cm 2 〕]]> 4.82 10.42 11.61 Voc〔V〕 0.34 0.86 0.66 FF 0.21 0.49 0.41 PCE〔%〕 0.35 4.23 3.10

[0491] The evaluation results show that the charge transporting composition using the polyimide material of the present invention can also be applied to solar cell elements.

[0492] <Fabrication of Perovskite Solar Cells>

[0493] [Example 5-1]

[0494] In a glove box filled with nitrogen, 504 mg of methylammonium iodide, 65 mg of methylammonium bromide, 1487 mg of lead (II) iodide, and 214 mg of lead (II) bromide were measured in a 5 mL vial. Next, 2346 μL of dimethyl sulfoxide (DMSO) and 586 μL of N,N-dimethylformamide were added to the vial, and heated and stirred at 70°C for 15 minutes to completely dissolve each weighed substance. 134 μL of cesium iodide solution dissolved in DMSO to a 1.5 mol / L solution was added to prepare a perovskite semiconductor compound (Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 ) 3 ) of the perovskite precursor solution (Pvsk).

[0495] Next, add [6,6]-phenyl-C 61 - 150 mg of methyl acetate (manufactured by Frontier Carbon Co., Ltd.) and 5000 μL of chlorobenzene were added, and the mixture was stirred for 15 minutes to prepare a composition for an electron trap layer ETL1.

[0496] Furthermore, 2.5 mg of bathocuproin (manufactured by Tokyo Chemical Industry Co., Ltd.) and 5000 μL of 2-propanol (manufactured by Kanto Chemical Co., Ltd.) were added to a 3 mL vial, and the mixture was stirred for 1 hour to prepare a composition for an electron trap layer ETL2.

[0497] A 25 mm × 25 mm glass substrate with an ITO transparent conductive layer that will become a cathode patterned in a strip shape of 10 mm × 25 mm was subjected to UV / ozone treatment for 15 minutes. The charge transport composition (D1) prepared in Example 1-5 was dripped onto the substrate, applied by spin coating, and heated on a hot plate at 100° C. for 10 minutes to form a hole trapping layer. The film thickness of the hole trapping layer was about 30 nm.

[0498] The substrate with the hole trapping layer was transferred to a glove box, and the perovskite precursor solution Pvsk was dripped onto the formed hole trapping layer, and SC coating was adopted. Chlorobenzene was dripped onto the substrate in SC. The obtained substrate was heated on a hot plate at 105°C for 30 minutes to form an active layer containing a perovskite semiconductor compound. The film thickness of the active layer was about 400nm.

[0499] The electron trap layer composition ETL1 was applied to the formed active layer by spin coating, and heated on a hot plate at 100° C. for 10 minutes. Furthermore, the electron trap layer composition ETL2 was applied to the substrate by spin coating to form an electron trap layer. The film thickness of the layer obtained from the electron trap layer composition ETL1 was about 30 nm, and the film thickness of the layer obtained from the electron trap layer composition ETL2 was about 8 nm.

[0500] Finally, the stacked substrates were placed in a vacuum deposition apparatus and evacuated until the vacuum level in the apparatus reached 1×10 -3 Pa, the silver layer that will become the anode is evaporated to a thickness of 100nm using the resistance heating method, thereby producing an inverse structure perovskite solar cell (D1-1) with an area of ​​8mm×3mm where the strip-shaped ITO layer and the silver layer intersect.

[0501] [Examples 5-2 to 5-8, Comparative Example 5-1]

[0502] Inverted structure perovskite solar cells (E1-1 to K1-1) were prepared by the same operation as in Example 5-1 except that the charge transporting composition (D1) was changed to the charge transporting compositions E1 to K1 and PEDOT:PSS, respectively.

[0503] The power generation performance of the inverted structure perovskite solar cell produced above was evaluated by the same operation as in Example 4-1. The results are shown in Table 6.

[0504] [Table 6]

[0505]

[0506] The evaluation results show that the charge transporting composition using the polyimide material of the present invention can also be applied to perovskite solar cells.

Claims

1. A charge transport composition for forming a charge transport thin film in an organic photoelectric conversion element, comprising a charge transport substance and an organic solvent, wherein the charge transport substance comprises: a polyimide-based polymer selected from at least one of a polyimide precursor obtained from a diamine component having a structure of the following formula (1) or (2) and a tetracarboxylic acid component, an ester of a polyimide precursor, and an imide compound of the polyimide precursor, [Chemistry 1] In the formula, R 1 represents a hydrogen atom or a monovalent organic group, and * represents a site bonded to another group. Any hydrogen atom constituting the benzene ring may be substituted with a monovalent organic group.

2. The charge transporting composition according to claim 1, in, The R 1 It is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a fluoroalkyl group having 1 to 5 carbon atoms, or a tert-butoxycarbonyl group. 3 . The charge transporting composition according to claim 1 , further comprising another charge transporting substance other than the polyimide polymer.

4. The charge transporting composition according to claim 3, in, The other charge transporting substance is at least one selected from polythiophene derivatives and polyaniline derivatives.

5. The charge transporting composition according to claim 4, in, The other charge transporting substance is at least one selected from a polythiophene derivative containing a repeating unit represented by the following formula (3) and a polyaniline derivative containing a repeating unit represented by the following formula (4), [Chemistry 2] In the formula, R 1t and R 2t each independently represents a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, -O-[ZO] p -R e , sulfonic acid group, sulfonate group or sulfonate group, or R 2 and R 3 -OYO-, Y is an alkylene group having 1 to 40 carbon atoms which may contain an ether bond and may be substituted with a sulfonic acid group, a sulfonate group, or a sulfonate group, Z is an alkylene group having 1 to 40 carbon atoms which may be substituted with a halogen atom, p is an integer greater than 1, R e is a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, or an aryl group having 6 to 20 carbon atoms, R 3t ~R 6t Each of them is independently a hydrogen atom, an alkyl group having 1 to 40 carbon atoms, a fluoroalkyl group having 1 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a fluoroalkoxy group having 1 to 40 carbon atoms, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfonate group or a sulfonate ester group. The charge transporting composition according to claim 1 , which is used for a hole trapping layer of an organic photoelectric conversion element.

7. The charge transporting composition according to claim 6, in, The organic photoelectric conversion element is an organic thin film solar cell, a perovskite solar cell, a dye-sensitized solar cell or a light sensor.

8. A charge transporting thin film obtained from the charge transporting composition according to claim 1.

9. The charge transport thin film according to claim 8, in, The charge transport thin film is a hole trapping layer of an organic photoelectric conversion element. 10 . An organic photoelectric conversion element comprising the charge transport thin film according to claim 8 .

11. The organic photoelectric conversion element according to claim 10, in, The organic photoelectric conversion element is an organic thin film solar cell, a perovskite solar cell, a dye-sensitized solar cell or a light sensor.

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