Photoelectric conversion element, ink for manufacturing photoelectric conversion element, method for manufacturing photoelectric conversion element, image sensor, and fingerprint authentication device

Abstract

Provided is a photoelectric conversion element in which an increase in dark current after heat treatment is suppressed. A photoelectric conversion element characterized by having an anode (12), a cathode (16), an active layer (14) provided between the anode (12) and the cathode (16), and intermediate layers (13, 15) provided between the anode (12) and the active layer (14) and / or between the cathode (16) and the active layer (14), the intermediate layers (13, 15) containing a nonionic insulating polymer.

Description

Technical Field

[0001] The present disclosure relates to a photoelectric conversion element, ink for manufacturing a photoelectric conversion element, a method for manufacturing a photoelectric conversion element, an image sensor, and a fingerprint authentication device. Background Art

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

[0003] Photoelectric conversion element refers to an element having an anode, a cathode, and an active layer disposed between the anode and the cathode. In a photoelectric conversion element, one electrode is made of a transparent or translucent material, and light is incident on the active layer from the transparent or translucent electrode side. The energy (hν) of the light incident on the active layer generates charges (holes and electrons) in the active layer, and the generated holes move to the anode, and the electrons move to the cathode. Then, the charges reaching the anode and the cathode are taken out to the outside of the element.

[0004] In the manufacture of a photoelectric conversion element, if electrodes (i.e., anode and cathode) are directly provided on the surface of an active layer, the active layer may be damaged. Therefore, a photoelectric conversion element may have an intermediate layer or the like provided between the electrode and the active layer.

[0005] Non-Patent Documents 1 and 2 describe a structure using an intermediate layer containing zinc oxide and PFN (poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl)fluorene]) or PEI (polyethyleneimine). [Prior art literature] [Patent Literature]

[0006] [Non-patent document 1] Solar Energy Materials & Solar Cells 141 (2015) 248-259 [Non-patent document 2] Organic Electronics 38 (2016) 150-157 Summary of the invention [Problems to be solved by the invention]

[0007] Photoelectric conversion elements are used, for example, as light detection elements. Photoelectric conversion elements used as light detection elements are used in a state where voltage is applied, and light incident on the element is converted into current for detection. However, even when light is not incident, a weak current flows through the photoelectric conversion element. This current is known as dark current, which is the main reason for reducing the accuracy of light detection.

[0008] Conventionally, when a photoelectric conversion element is mounted in an image sensor or the like, dark current may increase after heat treatment (180 to 230° C.) in the soldering and sealing process. Therefore, from the viewpoint of improving versatility, it is desired to develop a photoelectric conversion element with high heat resistance.

[0009] Therefore, an object of one embodiment of the present disclosure is to provide a photoelectric conversion element that suppresses an increase in dark current after heat treatment. Another embodiment of the present disclosure is to provide an ink for producing a photoelectric conversion element, the ink containing a nonionic insulating polymer. Another embodiment of the present disclosure aims to provide a method for manufacturing a photoelectric conversion element, which can obtain a photoelectric conversion element in which an increase in dark current after heat treatment is suppressed. A problem to be solved by another embodiment of the present disclosure is to provide a photodetection element that suppresses increase in dark current after heat treatment. Another embodiment of the present disclosure is to provide an image sensor including a photoelectric conversion element that suppresses increase in dark current after heat treatment. Another embodiment of the present disclosure is to provide a fingerprint authentication device including a photoelectric conversion element that suppresses increase in dark current after heat treatment.

Methods to solve the problem

[0010] The above-mentioned means for solving the problems include the following means. <1> A photoelectric conversion element, characterized in that anode, cathode, an active layer disposed between the anode and the cathode, at least one intermediate layer disposed between the anode and the active layer and between the cathode and the active layer, The intermediate layer contains a nonionic insulating polymer. <2> according to <1> In the photoelectric conversion element, the nonionic insulating polymer has a glass transition temperature of 100° C. or higher. <3> according to <1> or <2> In the photoelectric conversion element, the nonionic insulating polymer has a melting point of 150° C. or higher. <4> according to <1> ~ <3> The photoelectric conversion element according to any one of the preceding claims, wherein the nonionic insulating polymer is at least one selected from the group consisting of poly(meth)acrylic acid, polycarbonate, polyimide, and a fluorine-containing polymer. <5> according to <1> ~ <4> The photoelectric conversion element according to any one of the preceding claims, wherein the nonionic insulating polymer is polyimide. <6> according to <1> ~ <5> The photoelectric conversion element described in any one of the preceding claims, further comprising an intermediate layer between the cathode and the active layer. <7> according to <6> In the photoelectric conversion element, the cathode is a transparent or semi-transparent electrode. <8> according to <1> ~ <7> The photoelectric conversion element according to any one of the preceding claims, wherein the active layer contains a p-type semiconductor material. <9> according to <8> The photoelectric conversion element, wherein the p-type semiconductor material is a polymer compound containing at least one selected from the group consisting of a structural unit represented by the following formula (I) and a structural unit represented by the following formula (II).

[0011]

Chemical formula 1

[0012]

Chemical formula 2

[0013]

Chemical formula 3

[0014] In formula (I), Z represents any one of formulas (Z-1) to (Z-7), Ar 1 and Ar 2 represents the same or different trivalent aromatic heterocyclic groups. 3 In formulae (Z-1) to (Z-7), R each independently represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkenyl group which may have a substituent, a cycloalkenyl group which may have a substituent, an alkynyl group which may have a substituent, a cycloalkynyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, a cycloalkyloxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylthio group which may have a substituent, a cycloalkylthio group which may have a substituent, an arylthio group which may have a substituent, a monovalent heterocyclic group which may have a substituent, a substituted amino group which may have a substituent, an imide residue which may have a substituent, an amide group which may have a substituent, an imide group which may have a substituent, a substituted oxycarbonyl group which may have a substituent, a cyano group, a nitro group, a -C(=O)-R c A group represented by -SO2-R d The group represented by R c and R dEach independently represents a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, a cycloalkyloxy group which may have a substituent, an aryloxy group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. When there are multiple Rs, the multiple Rs may be the same or different from each other. <10> according to <1> In the photoelectric conversion element, the thickness of the intermediate layer is greater than 1 nm and less than 20 nm. <11> An ink for producing a photoelectric conversion element, characterized by containing a nonionic insulating polymer. <12> A method for manufacturing a photoelectric conversion element, characterized by comprising the steps of forming a coating film by coating an ink containing a nonionic insulating polymer, and drying the coating film. <13> according to <1> ~ <10> The photoelectric conversion element according to any one of the preceding claims, which is a light detection element. <14> An image sensor, characterized in that it comprises <13> The photoelectric conversion element. <15> A fingerprint authentication device, characterized in that it comprises <13> The photoelectric conversion element. [Effects of the invention]

[0015] According to one embodiment of the present disclosure, there is provided a photoelectric conversion element in which an increase in dark current after heat treatment is suppressed. According to another embodiment of the present disclosure, there is provided an ink for producing a photoelectric conversion element, the ink containing a nonionic insulating polymer. According to another embodiment of the present disclosure, there is provided a method for manufacturing a photoelectric conversion element capable of obtaining a photoelectric conversion element in which an increase in dark current after heat treatment is suppressed. According to another embodiment of the present disclosure, there is provided a light detection element which suppresses increase in dark current after heat treatment. According to another embodiment of the present disclosure, there is provided an image sensor including a photoelectric conversion element that suppresses increase in dark current after heat treatment. According to another embodiment of the present disclosure, there is provided a fingerprint authentication device including a photoelectric conversion element that suppresses increase in dark current after heat treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016]

Figure 1

Figure 2

Figure 3

[0017] The following is a description of an embodiment of the present disclosure. These descriptions and examples are examples of illustrative embodiments and do not limit the scope of the invention. In the numerical range recorded in stages in this specification, the upper limit or lower limit recorded in one numerical range can also be replaced by the upper limit or lower limit of the numerical range recorded in other stages. In addition, in the numerical range recorded in this specification, the upper limit or lower limit of the numerical range can also be replaced by the value shown in the embodiment.

[0018] Each component may also contain multiple matching substances. When referring to the amount of each component in a composition, when there are multiple substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the multiple substances present in the composition.

[0019] The “P-valent aromatic heterocyclic group” means an atomic group remaining after removing P hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting the ring from an aromatic heterocyclic compound which may have a substituent. The “P-valent heterocyclic group” (P represents an integer of 1 or greater) means an atomic group remaining after removing P hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting the ring from a heterocyclic compound which may have a substituent.

[0020] <Photoelectric conversion element> The photoelectric conversion element disclosed herein comprises an anode, a cathode, an active layer disposed between the anode and the cathode, and an intermediate layer disposed between the anode and the active layer and between the cathode and the active layer, wherein the intermediate layer contains a nonionic insulating polymer.

[0021] The present inventors have conducted intensive studies and, as a result, have found that the generation of dark current after heating can be suppressed by using a layer containing a nonionic insulating polymer as an intermediate layer, thereby completing the photoelectric conversion element according to the present disclosure.

[0022] (electrode) The photoelectric conversion element according to the present disclosure includes an anode and a cathode (hereinafter, the anode and the cathode are also collectively referred to as electrodes). Examples of the electrode include transparent or semi-transparent electrodes, such as conductive metal oxide films and semi-transparent metal thin films. Specific examples of the material of the electrode include indium oxide, zinc oxide, tin oxide, and their composites, such as indium tin oxide (ITO), indium zinc oxide (IZO), NESA, and other conductive materials; gold; platinum; silver; copper, etc. As the material of the electrode, ITO, IZO, or tin oxide is preferred. Alternatively, as the material of the electrode, organic compounds such as polyaniline and its derivatives, polythiophene and its derivatives may be used.

[0023] The electrode may also be an electrode with low light transmittance. As the material of the electrode with low light transmittance, for example, metals and conductive polymers can be listed. Specific examples of the material of the electrode with low light transmittance include metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, and ytterbium; alloys of two or more of these; alloys of one or more of these metals and one or more metals selected from gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, and tin; graphite; graphite intercalation compounds; polyaniline and its derivatives; polythiophene and its derivatives, etc. As alloys, magnesium-silver alloys, magnesium-indium alloys, magnesium-aluminum alloys, indium-silver alloys, lithium-aluminum alloys, lithium-magnesium alloys, lithium-indium alloys, and calcium-aluminum alloys can be listed.

[0024] At least one of the electrodes of the photoelectric conversion element according to the present disclosure is preferably a transparent or semi-transparent electrode. Furthermore, when the photoelectric conversion element according to the present disclosure has an intermediate layer between the cathode and the active layer, the cathode is preferably a transparent or semi-transparent electrode.

[0025] The thickness of the electrode is not particularly limited, and may be, for example, greater than 1 nm and less than 1000 nm, or greater than 100 nm and less than 500 nm. When the photoelectric conversion element disclosed herein is used as a light detection element, high light transmittance is required, so it is preferably greater than 5 nm and less than 200 nm.

[0026] As the method for forming the electrode, any preferred method known in the art can be used. As the method for forming the electrode, for example, a coating method such as vacuum evaporation, sputtering, ion plating, slit coating, or spin coating, and a plating method can be cited.

[0027] (Active layer) The photoelectric conversion element according to the present disclosure has an active layer provided between an anode and a cathode. The active layer preferably contains a p-type semiconductor material (electron donating compound), and more preferably contains a p-type semiconductor material (electron donating compound) and an n-type semiconductor material (electron withdrawing compound) (the details of the preferred p-type semiconductor material and n-type semiconductor material will be described below.). Whether it is a p-type semiconductor material or an n-type semiconductor material can be relatively determined by the HOMO energy level or LUMO energy level of the selected compound.

[0028] The thickness of the active layer is preferably 150 nm to 10,000 nm, and more preferably 200 nm to 1,000 nm.

[0029] The active layer can be formed by a coating method. Details of the p-type semiconductor material and n-type semiconductor material that can be contained in the active layer and the method for forming the active layer will be described below.

[0030] (Middle layer) The photoelectric conversion element according to the present disclosure has at least one intermediate layer provided between an anode and an active layer and between a cathode and an active layer. Furthermore, the intermediate layer contains a nonionic insulating polymer. From the viewpoint of suppressing the generation of dark current, the photoelectric conversion element according to the present disclosure preferably has an intermediate layer between the cathode and the active layer.

[0031] Nonionic means that it does not have a salt structure and does not have Bronsted acidity or Bronsted basicity. The presence or absence of Bronsted acidity or Bronsted basicity is determined using a pH meter. Specifically, the determination is performed as follows. A polymer solution is prepared by dissolving 5 g of the target polymer in 100 g of water. The temperature of the polymer solution is set at 25°C, and the pH of the polymer solution is measured with a pH meter. When the pH is 5 or less or 8 or more, it is considered to have Bronsted acidity or Bronsted basicity.

[0032] The insulating polymer refers to a polymer having a band gap of 3 eV or more at room temperature, preferably a polymer having a band gap of 3.5 eV or more. Room temperature refers to: 25℃±5℃. The band gap (Eg) can be calculated using the following formula using the light absorption edge wavelength of the polymer material to be measured. In the formula, h represents Planck's constant (6.626×10 -34 Js), c represents the speed of light (3×10 8 m / s). Formula: Eg = hc / absorption edge wavelength

[0033] In the above formula, the absorption edge wavelength can be measured by a spectrophotometer that can measure in the wavelength region of ultraviolet light, visible light, and near infrared light, for example, the ultraviolet visible near infrared spectrophotometer JASCO-V670 manufactured by JASCO Corporation can be used. In the absorption spectrum obtained by the spectrophotometer, that is, the absorption spectrum plotted by setting the vertical axis to the absorbance (absorption intensity) of the (polymer) compound and the horizontal axis to the wavelength, the absorption edge wavelength can be the value of the wavelength at the intersection of the baseline and the straight line fitted with the shoulder (high wavelength side) of the absorption peak as the absorption edge wavelength (nm).

[0034] From the viewpoint of suppressing increase in dark current, the glass transition temperature of the nonionic insulating polymer is preferably 100° C. or higher. The glass transition temperature is more preferably 150° C. or higher, and further preferably 200° C. or higher. The upper limit of the glass transition temperature is not particularly limited, and can be, for example, 400° C. or lower. Therefore, the glass transition temperature of the nonionic insulating polymer is preferably 100° C. or higher and 400° C. or lower, more preferably 150° C. or higher and 400° C. or lower, and further preferably 200° C. or higher and 400° C. or lower.

[0035] From the viewpoint of suppressing the increase of dark current, the melting point of the nonionic insulating polymer is preferably 150° C. or higher. The melting point of the nonionic insulating polymer is more preferably 200° C. or higher, and further preferably 300° C. or higher. The upper limit of the melting point of the nonionic insulating polymer is not particularly limited, and can be, for example, 600° C. or lower. Therefore, the melting point of the nonionic insulating polymer is preferably 150° C. to 600° C., more preferably 200° C. to 600° C., and even more preferably 300° C. to 600° C. The more preferred range of the melting point of the nonionic insulating polymer is 150° C. to 500° C., more preferably 200° C. to 500° C., and even more preferably 300° C. to 500° C.

[0036] The glass transition temperature and melting point can refer to the values ​​described in known documents including commercial manuals, or can be measured by "4.1 Differential Thermal Analysis (DTA)" or "4.2 Differential Scanning Calorimetry (DSC)" according to JIS-K7121: 2012. In any measurement method, the glass transition temperature and melting point of the preferred nonionic insulating polymer are within the above ranges.

[0037] The glass transition temperature and melting point are measured using a differential thermal analyzer or a differential scanning calorimeter. As a differential thermal analyzer, DTA-50 manufactured by Shimadzu Corporation can be used, and as a differential scanning calorimeter, DSC-60APlus manufactured by Shimadzu Corporation can be used.

[0038] The procedure for measuring the glass transition temperature and melting point using a differential thermal analyzer is, for example, as follows. The melting point is the endothermic peak temperature observed when a sample of 2 to 10 mg is heated from room temperature to 400° C. at a rate of 10° C. / min. The glass transition temperature can be determined by the method described in “9.3 Method for determining glass transition temperature” of JIS-K7121:2012.

[0039] The nonionic insulating polymer is preferably a non-conjugated polymer. The non-conjugated polymer refers to a polymer other than a conjugated polymer. A conjugated polymer refers to a polymer having a conjugated structure throughout the polymer.

[0040] Examples of nonionic insulating polymers include poly(meth)acrylic acid (e.g., polyacrylate, polymethacrylate, polyacrylonitrile, etc.); polyvinyl alcohol; polyester (e.g., polyethylene terephthalate, polyethylene naphthalate, etc.); naphthalate), polycarbonate, etc.); polyamide; vinyl polymer (e.g., polystyrene, polyvinyltoluene, polyvinylxylene, etc.); polyimide-based polymer; polysulfide; polysulfone; polyphenylene; polyphenylene ether; polyurethane; polyolefin (e.g., polypropylene, polymethylpentene, cyclic olefin, etc.); cellulose; silicone (e.g., polysilsesquioxane, polysilane, etc.); polyvinyl chloride; polyacetal; polynorbornene; synthetic rubber (e.g., ethylene-propylene rubber, styrene-butadiene rubber, ethylene-propylene-diene rubber, etc.); fluorine-containing polymer (e.g., polyvinylidene fluoride, polytetrafluoroethylene, polyhexafluoropropylene, CYTOP (registered trademark) of AGC, Lumiflon (registered trademark) of AGC, Teflon (registered trademark) of Dupon, etc.); acrylonitrile-butadiene-styrene copolymer (ABS); phenolic resin (e.g., novolac, etc.);

[0041] From the viewpoint of suppressing an increase in dark current, the nonionic insulating polymer is preferably at least one selected from the group consisting of poly(meth)acrylic acid, polycarbonate, polyimide polymers and fluorine-containing polymers, and more preferably a polyimide polymer.

[0042] The polyimide polymer can be produced using the following tetracarboxylic acid compound and diamine as raw materials. Alternatively, diisocyanate may be used as a raw material instead of diamine.

[0043] Polyimide refers to a polymer containing a structural unit containing an imide group, and polyamideimide refers to a polymer containing both a structural unit containing an imide group and a structural unit containing an amide group. The polyimide-based polymer refers to any polymer selected from polyimide and polyamideimide.

[0044] The polyimide-based polymer has a structural unit represented by formula (10). Here, in formula (10), G represents a tetravalent organic group, and A represents a divalent organic group. The polyimide polymer may contain two or more different structural units represented by formula (10). In addition, the polyimide polymer according to the present disclosure may contain any one or more structural units represented by any one of formula (11), formula (12) and formula (13).

[0045]

Chemical formula 4

[0046] In formula (10) and formula (11), G and G 1Each independently represents a tetravalent organic group, preferably a tetravalent organic group having 4 or more and 40 or less carbon atoms. The organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. In this case, the hydrocarbon group and the fluorine-substituted hydrocarbon group preferably have 1 or more and 8 or less carbon atoms. 1 , and examples thereof include a group represented by any one of formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) or formula (29); a tetravalent chain hydrocarbon group having 6 or less carbon atoms, etc. In formula (20) to formula (29), * represents a bonding point, and Z represents a single bond, -O-, -CH2-, -CH2-CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -Ar-, -SO2-, -CO-, -O-Ar-O-, -Ar-O-Ar-, -Ar-CH2-Ar-, -Ar-C(CH3)2-Ar- or -Ar-SO2-Ar-. Ar represents an arylene group having 6 or more and 20 or less carbon atoms which may have a fluorine atom, and a phenylene group can be cited as a specific example. In order to easily suppress the yellowness of the intermediate layer, G and G 1 , preferably a group represented by any one of formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26) or formula (27).

[0047]

Chemical formula 5

[0048] In formula (12), G 2 represents a trivalent organic group, preferably a trivalent organic group having 4 or more and 40 or less carbon atoms. The organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group, in which case the hydrocarbon group and the fluorine-substituted hydrocarbon group preferably have 1 or more and 8 or less carbon atoms. 2 Examples include a group in which any one of the bonding points of the group represented by any one of formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) or formula (29) is substituted by a hydrogen atom; a trivalent chain hydrocarbon group having 6 or less carbon atoms, etc. Examples of Z in the formula are the same as the examples of Z in the description of G.

[0049] In formula (13), G 3 represents a divalent organic group, preferably a divalent organic group having 4 to 40 carbon atoms. The organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group, in which case the hydrocarbon group and the fluorine-substituted hydrocarbon group preferably have 1 to 8 carbon atoms. 3Examples include a group in which two non-adjacent bonding points of a group represented by any one of formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) or formula (29) are substituted by hydrogen atoms; a divalent chain hydrocarbon group having 6 or less carbon atoms, etc. Examples of Z in the formula are the same as the examples of Z in the description of G.

[0050] In formula (10) to formula (13), A, A 1 , A 2 and A 3 A, A and B all represent divalent organic groups, preferably divalent organic groups having 4 to 40 carbon atoms. The organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms. In this case, the hydrocarbon group and the fluorine-substituted hydrocarbon group preferably have 1 to 8 carbon atoms. 1 , A 2 and A 3 , examples include a group represented by any one of formula (30), formula (31), formula (32), formula (33), formula (34), formula (35), formula (36), formula (37) or formula (38); a group in which any one of these is substituted by any one or more of methyl, fluoro, chloro or trifluoromethyl; a chain hydrocarbon group having no more than 6 carbon atoms, etc. In formula (30) to formula (38), * represents a bonding point, Z 1 , Z 2 and Z 3 Each independently represents a single bond, -O-, -CH2-, -CH2-CH2-, -CH(CH3)-, -C(CH3)2-, -C(CF3)2-, -SO2- or -CO-. An example is Z 1 and Z 3 is -O-, and Z 2 It is -CH2-, -C(CH3)2-, -C(CF3)2- or -SO2-. Z 1 and Z 2 and Z 2 and Z 3 They are preferably located at the meta-position or para-position relative to each ring, respectively.

[0051]

Chemical formula 6

[0052] Polyimide polymers are obtained, for example, by polycondensation of diamines and tetracarboxylic acid compounds (tetracarboxylic dianhydride, etc.), and can be synthesized, for example, by the method described in Japanese Patent Application Publication No. 2006-199945 or Japanese Patent Application Publication No. 2008-163107. Examples of polyimide polymers include Neoprim manufactured by Mitsubishi Gas Chemical Co., Ltd. and KPI-MX300F manufactured by Kawamura Industrial Co., Ltd.

[0053] As tetracarboxylic acid compounds for synthesizing polyimide-based polymers, aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic dianhydrides and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydrides can be listed. The tetracarboxylic acid compound can be used alone or in combination of two or more. In addition to tetracarboxylic dianhydrides, the tetracarboxylic acid compound can also be a tetracarboxylic acid compound analogue such as a tetraacyl chloride compound.

[0054] Examples of the aromatic tetracarboxylic dianhydride include non-condensed polycyclic aromatic tetracarboxylic dianhydride, monocyclic aromatic tetracarboxylic dianhydride, and condensed polycyclic aromatic tetracarboxylic dianhydride. Examples of the non-condensed polycyclic aromatic tetracarboxylic dianhydride include 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane Dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic acid dianhydride (sometimes also described as 6FDA), 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,2-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(phenylenedioxy) diphthalic acid dianhydride, 4,4'-(isophenylenedioxy) diphthalic acid dianhydride. In addition, as a monocyclic aromatic tetracarboxylic acid dianhydride, 1,2,4,5-pyromellitic acid dianhydride can be mentioned, and as a condensed polycyclic aromatic tetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride can be mentioned.

[0055] Among them, preferably, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane The dianhydride may be 1,2-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(phenylenedioxy)diphthalic dianhydride and 4,4'-(isophenylenedioxy)diphthalic dianhydride. More preferred examples include 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), bis(3,4-dicarboxyphenyl)methane dianhydride and 4,4'-(phenylenedioxy)diphthalic dianhydride. These can be used alone or in combination of two or more.

[0056] As aliphatic tetracarboxylic dianhydride, cyclic or non-cyclic aliphatic tetracarboxylic dianhydride can be cited. Cyclic aliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having an alicyclic hydrocarbon structure. As specific examples thereof, cycloalkyl tetracarboxylic dianhydrides such as 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl-3,3'-4,4'-tetracarboxylic dianhydride and positional isomers thereof can be cited. These can be used alone or in combination of two or more. As specific examples of non-cyclic aliphatic tetracarboxylic dianhydride, 1,2,3,4-butane tetracarboxylic dianhydride, 1,2,3,4-pentane tetracarboxylic dianhydride, etc. can be cited, and these can be used alone or in combination of two or more.

[0057] From the perspective of transparency and color suppression of the intermediate layer, as a tetracarboxylic acid compound, the above-mentioned alicyclic tetracarboxylic dianhydride or non-condensed polycyclic aromatic tetracarboxylic dianhydride can be preferably listed. As a more preferred specific example, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA) can be listed. These can be used alone or in combination of two or more.

[0058] The polyimide polymer may be a product obtained by further reacting tetracarboxylic acid, tricarboxylic acid compound, dicarboxylic acid compound, and anhydrides or derivatives thereof, in addition to the above-mentioned anhydrides of tetracarboxylic acids used for the synthesis of polyimide.

[0059] Examples of the tricarboxylic acid compound include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and acid chloride compounds and anhydrides thereof. Two or more of these may be used in combination. Specific examples of tricarboxylic acid compounds include the anhydride of 1,2,4-benzenetricarboxylic acid; 2,3-anhydride of 2,3,6-naphthalenetricarboxylic acid; compounds formed by phthalic anhydride and benzoic acid connected by a single bond, -CH2-, -C(CH3)2-, -C(CF3)2-, -SO2- or any one of phenylene groups; and the like.

[0060] Examples of dicarboxylic acid compounds include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and similar acyl chloride compounds and anhydrides thereof. Two or more of these may be used in combination. Specific examples thereof include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, 4,4'-biphenyldicarbon acid, 3,3'-biphenyldicarbon acid, dicarboxylic acid compounds of chain hydrocarbons having 8 or less carbon atoms, and two benzoic acid skeletons with -CH2-, -S-, -C(CH3)2-, -C(CF3)2-, -O-, -NR 9 A compound in which any one of -, -C(=O)-, -SO2- or phenylene is linked. These may be used alone or in combination of two or more.

[0061] As the dicarboxylic acid compound, terephthalic acid; isophthalic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; and two benzoic acid skeletons with -CH2-, -C(=O)-, -O-, -NR 9 -, -SO2- or phenylene, preferably terephthalic acid; 4,4'-biphenyl dicarboxylic acid; and two benzoic acid skeletons with -O-, -NR 9 These can be used alone or in combination of two or more. R 9 It represents a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom.

[0062] The ratio of the tetracarboxylic acid compound to the total amount of the tetracarboxylic acid compound, the tricarboxylic acid compound and the dicarboxylic acid compound is preferably 40 mol% or more, more preferably 50 mol% or more, further preferably 70 mol% or more, further preferably 90 mol% or more, particularly preferably 98 mol% or more.

[0063] As diamines for synthesizing polyimide-based polymers, aliphatic diamines, aromatic diamines or mixtures thereof can be cited. In addition, in this specification, "aromatic diamine" means a diamine in which an amino group is directly bonded to an aromatic ring, and a part of its structure may also contain an aliphatic group or other substituents. The aromatic ring may be a single ring or a condensed ring, and examples thereof include, but are not limited to, a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring. Among them, a benzene ring can be preferably cited. In addition, "aliphatic diamine" means a diamine in which an amino group is directly bonded to an aliphatic group, and a part of its structure may also contain an aromatic ring or other substituents.

[0064] Examples of the aliphatic diamine include non-cyclic aliphatic diamines such as hexamethylenediamine and cyclic aliphatic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, norbornanediamine, and 4,4′-diaminodicyclohexylmethane. These can be used alone or in combination of two or more.

[0065] Examples of the aromatic diamine include aromatic diamines having one aromatic ring, such as p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-phenylenediamine, p-phenylenediamine, 1,5-diaminonaphthalene, and 2,6-diaminonaphthalene; 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, bis(4-(4-aminophenoxy)propane)- ...sulfone, 3,3'-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)propane, 1,3-bis(4-aminophenoxy)propane, 1,3-bis(4-aminophenoxy)propane, 1,3-bis(4-aminophenoxy)propane, 1,3-bis Aromatic diamines having two or more aromatic rings such as bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (sometimes also referred to as TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, 9,9-bis(4-amino-3-chlorophenyl)fluorene, and 9,9-bis(4-amino-3-fluorophenyl)fluorene. These may be used alone or in combination of two or more.

[0066] Preferred aromatic diamines include 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)benzidine, )-4,4'-diaminobiphenyl (TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 4,4'-bis(4-aminophenoxy)biphenyl. These may be used alone or in combination of two or more.

[0067] The diamine may have a fluorine-based substituent. Examples of the fluorine-based substituent include a perfluoroalkyl group having 1 to 5 carbon atoms, such as a trifluoromethyl group, and a fluorine group.

[0068] Among the diamines, from the viewpoint of high transparency and low coloring, it is preferred to use one or more selected from aromatic diamines having a biphenyl structure, and specifically, it is preferred to use one or more selected from 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB) and 4,4'-bis(4-aminophenoxy)biphenyl. It is more preferred to use a diamine having a biphenyl structure and a fluorine-based substituent, and specifically, it is more preferred to use 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB).

[0069] The polyimide polymer is a condensation polymer formed by polycondensation of a diamine and a tetracarboxylic acid compound (including tetracarboxylic acid compound analogs such as acyl chloride compounds and tetracarboxylic dianhydride), and comprising a structural unit represented by formula (10). In addition, tricarboxylic acid compounds (including tricarboxylic acid compound analogs such as acyl chloride compounds and tricarboxylic anhydride) and dicarboxylic acid compounds (including analogs such as acyl chloride compounds) are sometimes further used as starting materials. The structural units represented by formula (10) and formula (11) are generally derived from diamines and tetracarboxylic acid compounds. The structural units represented by formula (12) are generally derived from diamines and tricarboxylic acid compounds. The structural units represented by formula (13) are generally derived from diamines and dicarboxylic acid compounds. Specific examples of diamines, tetracarboxylic acid compounds, tricarboxylic acid compounds and dicarboxylic acid compounds are as described above.

[0070] The molar ratio of diamine to carboxylic acid compounds such as tetracarboxylic acid compounds can be appropriately adjusted within the range of preferably 0.9 mol to 1.1 mol of tetracarboxylic acid relative to 1.00 mol of diamine. In order to exhibit high folding resistance, the obtained polyimide polymer preferably has a high molecular weight, and therefore, the tetracarboxylic acid is more preferably 0.98 mol to 1.02 mol, and further preferably 0.99 mol% to 1.01 mol% relative to 1.00 mol of diamine. Furthermore, from the viewpoint of suppressing the yellowness of the obtained intermediate layer, the ratio of the amino group in the obtained polymer terminal is preferably low, and is preferably 1.00 mol or more of the carboxylic acid compound such as the tetracarboxylic acid compound per 1.00 mol of the diamine.

[0071] With the quality of polyimide-based polymer as a benchmark, the fluorine atoms in the molecule of diamine and carboxylic acid compound (for example, tetracarboxylic acid compound) can be adjusted so that the fluorine amount in the polyimide-based polymer obtained is more than 1 mass %, more than 5 mass %, more than 10 mass %, more than 20 mass %.The higher the ratio of fluorine, the higher the raw material cost, so the upper limit of fluorine amount is preferably less than 40 mass %.The fluorine-based substituent group can also be present in any one of diamine or carboxylic acid compound, or can be present in both.

[0072] The polyimide polymer may also be a copolymer containing a plurality of different types of the above structural units. The weight average molecular weight of the polyimide polymer, calculated in terms of standard polystyrene, is usually 100,000 to 800,000, preferably 200,000 to 700,000, more preferably 300,000 to 600,000, and even more preferably 350,000 to 500,000.

[0073] From the viewpoint of light transmittance, the polyimide-based polymer preferably has a fluorine-containing substituent. Specific examples of the fluorine-containing substituent include a fluorine group and a trifluoromethyl group.

[0074] The intermediate layer may or may not contain components other than the nonionic insulating polymer. Examples of other components include components contained in the second intermediate layer described below, such as hole transporting materials and electron transporting materials.

[0075] From the viewpoint of suppressing the increase of dark current, the content of the nonionic insulating polymer in the intermediate layer is preferably 80 mass % or more and 100 mass % or less, preferably 90 mass % or more and 100 mass % or less, and further preferably 95 mass % or more and 100 mass % or less, relative to the mass of the entire intermediate layer.

[0076] From the viewpoint of easy charge transfer, the thickness of the intermediate layer is preferably 1 nm to 100 nm, more preferably 1 nm to 20 nm, and even more preferably 1 nm to 15 nm.

[0077] The intermediate layer can be formed by a coating method. The details of the method for forming the intermediate layer are as follows.

[0078] (Second middle layer) The photoelectric conversion element according to the present disclosure may include a second intermediate layer that does not contain the nonionic insulating polymer as required. The second intermediate layer is also referred to as a hole transport layer, an electron transport layer, a hole injection layer, an electron injection layer, etc. according to its function. The hole transport layer is a layer having a function of transporting holes from the active layer to the electrode. The hole injection layer refers to a hole transport layer provided in contact with the anode. The electron transport layer is a layer having a function of transporting electrons from the active layer to the electrode. The electron injection layer refers to an electron transport layer provided in contact with the cathode.

[0079] As a material for the second intermediate layer, any conventionally known preferred material can be used. Examples of the material for the second intermediate layer include halides and oxides of alkali metals or alkaline earth metals such as lithium fluoride. Examples of the material used for the second intermediate layer include fine particles of an inorganic semiconductor material such as titanium oxide and a mixture of PEDOT (poly(3,4-ethylenedioxythiophene)) and PSS (poly(4-styrenesulfonate)) (PEDOT:PSS).

[0080] When the second intermediate layer is a hole transport layer, the photoelectric conversion element preferably includes a hole transport layer (hole injection layer) between the anode and the active layer. The hole transport layer may be a single layer or may be a stack of two or more layers. The hole transport layer (hole injection layer) may be in contact with the active layer.

[0081] The hole transport layer contains a hole transport material. Examples of the hole transport material include polythiophene and its derivatives, aromatic amine compounds, polymer compounds containing a structural unit having an aromatic amine residue, CuSCN, CuI, NiO, and molybdenum oxide (MoO3).

[0082] When the second intermediate layer is an electron transport layer, the photoelectric conversion element preferably includes an electron transport layer (or an electron injection layer; the same applies hereinafter) between the cathode and the active layer. The electron transport layer may be a single layer or may be a stack of two or more layers. The electron transport layer may be in contact with the active layer.

[0083] The electron transport layer contains an electron transport material. As the electron transport material, any preferred material that contributes to the movement of electrons in the layer constituting the photoelectric conversion element can be cited. As the electron transport material, for example, metal compounds and compounds having an alkylene structure can be cited.

[0084] Examples of metal compounds include metal oxides, metal hydroxides, and metal alkoxides. The metal compound is preferably a metal oxide, metal hydroxide, or metal alkoxide containing a divalent or higher metal; more preferably, it may be a metal oxide, metal hydroxide, or metal alkoxide containing zinc or titanium. Examples of the metal alkoxide include metal methoxide, metal ethoxide, metal propoxide, metal isopropoxide, metal n-butoxide, metal sec-butoxide, metal isobutoxide, and metal tert-butoxide. Examples of the metal oxide include zinc oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, titanium oxide, and niobium oxide. As the metal oxide, a metal oxide containing zinc is preferred, and zinc oxide is preferred among them.

[0085] As the metal alkoxide, a metal alkoxide containing titanium is preferred, and titanium (IV) isopropoxide is particularly preferred.

[0086] Examples of compounds having an alkylene structure include polyalkyleneimines and their derivatives. Examples of polyalkyleneimines and their derivatives include polymers obtained by polymerizing one or more alkenylimines having 2 to 8 carbon atoms, particularly alkenylimines having 2 to 4 carbon atoms, such as ethyleneimine, propyleneimine, butyleneimine, dimethylethyleneimine, pentyleneimine, hexyleneimine, heptyleneimine, and octyleneimine by conventional methods, and polymers chemically modified by reacting these with various compounds. Polyalkyleneimines and their derivatives are preferably polyethyleneimine (PEI) and polyethyleneimine ethoxylates (PEIE: ethoxylated polyethyleneimine) containing polyethyleneimine as the main chain and ethylene oxide added to the nitrogen atom in the main chain.

[0087] The second intermediate layer can be formed by a coating method. The details of the method for forming the second intermediate layer are as follows.

[0088] (Substrate) The photoelectric conversion element according to the present disclosure may include a substrate. The photoelectric conversion element is usually formed on a substrate. The substrate usually has an electrode formed therein. The material of the substrate is not particularly limited. As the material of the substrate, for example, glass, plastic, polymer film, silicon, etc. can be cited. When the substrate is opaque, preferably, the electrode on the opposite side of the electrode arranged on the opaque substrate side (i.e., the electrode on the side away from the substrate) is a transparent or translucent electrode.

[0089] (Configuration Example of Photoelectric Conversion Element) The following describes configuration examples that can be adopted by the photoelectric conversion element according to the present disclosure. Figure 1 This is a schematic cross-sectional view of a photoelectric conversion element according to one embodiment of the present disclosure. like Figure 1As shown, the photoelectric conversion element 10 according to the present disclosure is provided, for example, on a substrate (support substrate) 11. The photoelectric conversion element 10 includes an electrode 12 provided in contact with the substrate 11, a second intermediate layer or a layer 13 provided in contact with the electrode 12, an active layer 14 provided in contact with the second intermediate layer or the intermediate layer 13, a second intermediate layer or a layer 15 provided in contact with the active layer 14, and an electrode 16 provided in contact with the second intermediate layer or the layer 15. In this configuration example, a substrate 17 provided so as to be in contact with the electrode 16 is further provided.

[0090] Here, in the photoelectric conversion element 10 according to the present disclosure, it is preferred that the electrode 12 is an anode, the layer 13 is a second intermediate layer, the layer 15 is an intermediate layer, and the electrode 16 is a cathode.

[0091] (Application of photoelectric conversion element) The photoelectric conversion element according to the present disclosure can generate a photovoltage between electrodes based on irradiation with light, and can function as a solar cell. In addition, a thin-film solar cell module can be obtained by stacking a plurality of solar cells.

[0092] The photoelectric conversion element disclosed in the present invention can function as a light detection element (photosensor) by irradiating light from a transparent or semi-transparent electrode side while a voltage is applied between the electrodes to allow photocurrent to flow. In addition, it can also be used as an image sensor by stacking a plurality of photosensors.

[0093] The photoelectric conversion element according to the present disclosure can be preferably applied to detection parts of various electronic devices such as workstations, personal computers, mobile information terminals, access control systems, digital cameras, and medical equipment.

[0094] The photoelectric conversion element disclosed herein can be preferably applied to: the image detection parts (image sensors) used in solid-state imaging devices such as X-ray cameras and CMOS image sensors, detection parts for detecting a part of a specified feature of a biological body such as a fingerprint detection part, a face detection part, a vein detection part, and an iris detection part, and detection parts of optical biosensors such as a pulse oximeter, etc., which are possessed by the electronic devices exemplified above.

[0095] Hereinafter, among the detection parts to which the photoelectric conversion element involved in the present disclosure can be preferably applied, a configuration example of an image detection part for a solid-state imaging device and a fingerprint detection part for a biometric information authentication device (fingerprint authentication device) will be described with reference to the drawings.

[0096] -Image Detection Part- Figure 2 is a schematic cross-sectional view of an image detection portion for a solid-state imaging device. The image detection part 1 includes: a CMOS transistor substrate 20, an interlayer insulating film 30 arranged to cover the CMOS transistor substrate 20, a photoelectric conversion element 10 arranged on the interlayer insulating film 30 and involved in the present disclosure, an interlayer wiring part 32 arranged to penetrate the interlayer insulating film 30 and electrically connected to the CMOS transistor substrate 20 and the photoelectric conversion element 10, a sealing layer 40 arranged to cover the photoelectric conversion element 10, and a color filter 50 arranged on the sealing layer 40. The CMOS transistor substrate 20 has any conventionally known preferred configuration according to the design form.

[0097] The CMOS transistor substrate 20 includes functional elements such as transistors and capacitors formed within the thickness of the substrate, and a CMOS transistor circuit (MOS transistor circuit) for realizing various functions. As the functional element, for example, a floating diffusion, a reset transistor, an output transistor, and a selection transistor can be cited. By using such functional elements, wirings, and the like, a signal reading circuit and the like are improved in the CMOS transistor substrate 20 .

[0098] The interlayer insulating film 30 can be made of any conventionally known preferred insulating material, such as silicon oxide, insulating resin, etc. The interlayer wiring portion 32 can be made of any conventionally known preferred conductive material (wiring material), such as copper, tungsten, etc. The interlayer wiring portion 32 can be, for example, a via wiring formed simultaneously with the formation of the wiring layer, or a buried plug formed separately from the wiring layer.

[0099] The sealing layer 40 may be formed of any conventionally known preferred material as long as it can prevent or suppress the penetration of harmful substances such as oxygen and water that may deteriorate the functionality of the photoelectric conversion element 10. The sealing layer 40 may also be formed of the sealing substrate 17 described above.

[0100] The color filter 50 may be made of any preferred material known in the past, and may be, for example, a primary color filter corresponding to the design of the image detection portion 1. In addition, as the color filter 50, a complementary color filter whose thickness can be reduced compared to the primary color filter may be used. As the complementary color filter, for example, a color filter composed of three colors (yellow, cyan, magenta), three colors (yellow, cyan, transparent), three colors (yellow, transparent, magenta), and three colors (transparent, cyan, magenta) may be used. As long as color image data can be generated, any preferred configuration may be adopted corresponding to the design of the photoelectric conversion element 10 and the CMOS transistor substrate 20.

[0101] The light received by the photoelectric conversion element 10 through the color filter 50 is converted into an electric signal corresponding to the amount of received light by the photoelectric conversion element 10 and output to the outside of the photoelectric conversion element 10 through the electrode as a light reception signal, that is, an electric signal of the photographic object.

[0102] Then, the light-receiving signal output from the photoelectric conversion element 10 is input into the CMOS transistor substrate 20 via the interlayer wiring portion 32, read by a signal reading circuit built into the CMOS transistor substrate 20, and processed by any further preferred previously known functional portion not shown to generate image information based on the photographed object.

[0103] -Fingerprint detection part- Figure 3 is a schematic cross-sectional view of a fingerprint detection portion integrally formed with a display device. The display device 2 of the mobile information terminal includes a fingerprint detection section 100 including the photoelectric conversion element 10 according to the present disclosure as a main component, and a display panel section 200 provided on the fingerprint detection section 100 and displaying a predetermined image.

[0104] In this configuration example, the fingerprint detection section 100 is provided in a region substantially coinciding with the display region 200a of the display panel section 200. In other words, the display panel section 200 is integrally stacked above the fingerprint detection section 100. When fingerprint detection is performed only in a partial area of ​​the display area 200a, the fingerprint detection part 100 is only provided corresponding to the partial area.

[0105] The fingerprint detection part 100 includes the photoelectric conversion element 10 involved in the present disclosure as a functional part that performs basic functions. The fingerprint detection part 100 can be equipped with any preferred previously known components such as a protection film (not shown), a supporting substrate, a sealing substrate, a sealing component, a barrier film, a bandpass filter, an infrared cut-off film, etc. in a corresponding manner of design that can obtain desired characteristics. The fingerprint detection part 100 can also adopt the structure of the image detection part described above.

[0106] The photoelectric conversion element 10 may be included in the display region 200a in any manner. For example, a plurality of photoelectric conversion elements 10 may be arranged in a matrix. As described above, the photoelectric conversion element 10 is provided on the supporting substrate 11 or the sealing substrate, and electrodes (anodes or cathodes) are provided in a matrix form on the supporting substrate 11 , for example. The light received by the photoelectric conversion element 10 is converted into an electric signal corresponding to the amount of light received by the photoelectric conversion element 10 , and is output to the outside of the photoelectric conversion element 10 via the electrode as an electric signal corresponding to the light received, that is, an electric signal of the photographed fingerprint.

[0107] In this configuration example, the display panel portion 200 is configured as an organic electroluminescent display panel (organic EL display panel) including a touch sensor panel. The display panel portion 200 may be configured by a display panel of any preferred conventionally known configuration, such as a liquid crystal display panel including a light source such as a backlight, instead of the organic EL display panel. The display panel portion 200 is provided on the fingerprint detection portion 100 described above. The display panel portion 200 includes an organic electroluminescent element (organic EL element) 220 as a functional portion that performs a basic function. The display panel portion 200 can also further include any preferred conventionally known components such as a substrate (support substrate 210 or sealing substrate 240) such as a glass substrate, a sealing member, a barrier film, a polarizing plate such as a circular polarizing plate, and a touch sensor panel 230 in a manner corresponding to the desired characteristics.

[0108] In the configuration example described above, the organic EL element 220 is used as a light source for the pixels in the display region 200 a and also as a light source for capturing the fingerprint in the fingerprint detection section 100 .

[0109] Here, the operation of the fingerprint detection section 100 will be briefly described. When fingerprint authentication is performed, the fingerprint detection section 100 detects the fingerprint using the light emitted from the organic EL element 220 of the display panel section 200. Specifically, the light emitted from the organic EL element 220 passes through the components existing between the organic EL element 220 and the photoelectric conversion element 10 of the fingerprint detection section 100, and is reflected by the skin (finger surface) of the fingertip of the finger placed in contact with the surface of the display panel section 200 in the display area 200a. At least a portion of the light reflected by the finger surface passes through the components existing therebetween, is received by the photoelectric conversion element 10, and is converted into an electrical signal corresponding to the amount of light received by the photoelectric conversion element 10. Then, image information of the fingerprint on the finger surface is constructed from the converted electrical signal.

[0110] The mobile information terminal including the display device 2 compares the image information obtained through any conventionally known preferred procedure with the fingerprint data for fingerprint authentication recorded in advance, and performs fingerprint authentication.

[0111] <Method for manufacturing photoelectric conversion element> The method for producing a photoelectric conversion element according to the present disclosure includes the steps of forming a coating film by applying ink containing a nonionic insulating polymer, and drying the coating film. Hereinafter, as an example of a method for manufacturing a photoelectric conversion element, a method for manufacturing a photoelectric conversion element having a structure in which a substrate (support substrate), an electrode, a second intermediate layer or an intermediate layer, an active layer, a second intermediate layer or an intermediate layer, and an electrode are stacked in sequence will be described.

[0112] (Step of forming electrodes on substrate) In this step, a supporting substrate provided with electrodes is prepared. The method for forming the electrode on the support substrate is not particularly limited. The electrode can be formed on the support substrate by, for example, vacuum deposition, sputtering, ion plating, plating, or the like. Examples of the material for the electrode include the compounds exemplified as the material for the electrode described above.

[0113] Alternatively, a supporting substrate provided with electrodes can be prepared by obtaining a substrate provided with electrodes from the market, and patterning a conductive thin film as necessary to form electrodes.

[0114] (Step of forming a second intermediate layer or intermediate layer-1) In this step, a second intermediate layer or an intermediate layer is formed on the electrode of the substrate provided with the electrode. First, the step of forming the intermediate layer in this process will be described.

[0115] -Process for forming an intermediate layer- This step is a step of forming a coating film by applying ink containing a nonionic insulating polymer (hereinafter also referred to as "specific ink") and drying the coating film.

[0116] The specific ink preferably contains a nonionic insulating polymer and a solvent. As the nonionic insulating polymer contained in the specific ink, the nonionic insulating polymer according to the present disclosure is preferably used. Examples of the solvent include water, alcohols, ketones, and hydrocarbons. The specific ink may contain only one type of solvent or may contain two or more types of solvents.

[0117] From the viewpoint of suppressing the influence on the active layer adjacent to the intermediate layer, the alcohol is preferably an alcohol having 1 to 6 carbon atoms. Specific examples of the alcohol include ethanol, 1-propanol, 2-propanol, 2-butanol, 2-pentanol, 3-pentanol, ethylene glycol, propylene glycol, butoxyethanol, and methoxybutanol.

[0118] Specific examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone.

[0119] The specific ink may contain other components besides the nonionic insulating polymer and the solvent. Examples of the other components include components contained in the second intermediate layer, such as hole transporting materials and electron transporting materials.

[0120] When the total mass of the nonionic insulating polymer and other components contained in the specific ink is 1 mass part, the content of the solvent in the specific ink is preferably 1 mass part to 10000 mass parts, and more preferably 10 mass parts to 1000 mass parts.

[0121] The specific ink may be a solution, or may be a dispersion such as a dispersion, an emulsion, or a suspension.

[0122] In this step, a specific ink is applied onto the electrodes of a substrate provided with the electrodes to form a coating film. As a method of applying the specific ink, any coating method can be used. As the coating method, slit coating, blade coating, spin coating, micro gravure coating, gravure coating, rod coating, inkjet printing, nozzle coating or capillary coating is preferred, spin coating, capillary coating or rod coating is more preferred, and spin coating is further preferred.

[0123] Then, in this step, the coating film is dried. As a method for forming an intermediate layer by drying the coating film, any preferred method can be used. Examples of the drying method include a method of directly heating using a hot plate, hot air drying, infrared heating drying, flash annealing drying, and reduced pressure drying.

[0124] -Step of forming the second intermediate layer- Next, the step of forming the second intermediate layer in this step will be described. This step is a step of forming a coating film by applying the ink for forming the second intermediate layer and drying the coating film.

[0125] When forming the hole transport layer, the second intermediate layer forming ink preferably contains a hole transport material and a solvent. When forming the electron transport layer, the second intermediate layer forming ink preferably contains an electron transport material and a solvent.

[0126] As the hole transport material and the electron transport material contained in the ink for forming the second intermediate layer, the same materials as the hole transport material and the electron transport material that can be contained in the second intermediate layer described above can be used. As a solvent, for example, water, alcohol, ketone and hydrocarbon can be cited. As a specific example of alcohol, methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol, butoxyethanol and methoxybutanol can be cited. As a specific example of ketone, acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone and cyclohexanone can be cited. As a specific example of hydrocarbon, n-pentane, cyclohexane, n-hexane, benzene, toluene, xylene, tetralin, chlorobenzene and o-dichlorobenzene can be cited. The ink for forming the second intermediate layer can contain one solvent alone or more than two solvents. When the total mass of the hole transport material and the electron transport material contained in the ink for forming the second intermediate layer is set to 1 mass part, the amount of the solvent in the ink for forming the second intermediate layer is preferably more than 1 mass part and less than 10000 mass parts, and more preferably more than 10 mass parts and less than 1000 mass parts.

[0127] As a method for applying the ink for forming the second intermediate layer (coating method), the coating method described in the above-mentioned "-Step of forming the intermediate layer-" can be applied.

[0128] As a method for forming the second intermediate layer by drying the coating film, any preferred method may be used. As an example of the drying method, the same method as the drying method described in the above-mentioned "-Step of forming the intermediate layer-" may be applied.

[0129] (Active Layer Formation Step) This step is a step of forming a coating film by applying the active layer forming ink and drying the coating film. The active layer forming ink contains a p-type semiconductor material, an n-type semiconductor material, and a solvent.

[0130] -p-type semiconductor material- As p-type semiconductor materials, for example, polyvinyl carbazole and its derivatives; polysilane and its derivatives; polysiloxane derivatives containing aromatic amine structures in the side chain or the main chain; polyaniline and its derivatives; polythiophene and its derivatives; polypyrrole and its derivatives; polyphenylene vinylene and its derivatives; polythiophene ethylene and its derivatives; polyfluorene and its derivatives, etc.

[0131] Preferably, the p-type semiconductor material is a polymer compound containing at least one selected from the group consisting of a structural unit represented by the following formula (I) and a structural unit represented by the following formula (II).

[0132]

Chemical formula 7

[0133] In formula (I), Z represents a group represented by any one of the following formulae (Z-1) to (Z-7). 1 and Ar 2represent the same or different trivalent aromatic heterocyclic groups.

[0134]

Chemical formula 8

[0135] In formula (II), Ar 3 It represents a divalent aromatic heterocyclic group.

[0136]

Chemical formula 9

[0137] In formulae (Z-1) to (Z-7), R each independently represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkenyl group which may have a substituent, a cycloalkenyl group which may have a substituent, an alkynyl group which may have a substituent, a cycloalkynyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, a cycloalkyloxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylthio group which may have a substituent, a cycloalkylthio group which may have a substituent, an arylthio group which may have a substituent, a monovalent heterocyclic group which may have a substituent, a substituted amino group which may have a substituent, an imide residue which may have a substituent, an amide group which may have a substituent, an imide group which may have a substituent, a substituted oxycarbonyl group which may have a substituent, a cyano group, a nitro group, a -C(=O)-R c A group represented by -SO2-R d The group represented by R c and R d Each independently represents a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, a cycloalkyloxy group which may have a substituent, an aryloxy group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. When there are multiple Rs, the multiple Rs may be the same or different from each other.

[0138] The structural unit represented by the formula (I) is preferably a structural unit represented by the following formula (I-1).

[0139]

Chemical formula 10

[0140] In formula (I-1), Z has the same meaning as Z in formula (I). In formula (I-1), Z is preferably a group selected from the group represented by formula (Z-4) to formula (Z-7).

[0141] Examples of the structural unit represented by formula (I-1) include structural units represented by the following formulae (501) to (505), and the structural unit represented by formula (501) is preferred.

[0142]

Chemical formula 11

[0143] In formulae (501) to (505), R each independently has the same meaning as R in formulae (Z-1) to (Z-7). When a plurality of Rs exist, the plurality of Rs may be the same as or different from each other.

[0144] In formula (II), Ar 3 The carbon number of the divalent aromatic heterocyclic group represented by is usually 2 to 60, preferably 4 to 60, and more preferably 4 to 20. 3 The divalent aromatic heterocyclic group represented by may have a substituent.

[0145] As Ar 3 Examples of the divalent aromatic heterocyclic group represented by include groups represented by the following formulae (101) to (185).

[0146]

Chemical formula 12

[0147]

Chemical formula 13

[0148]

Chemical formula 14

[0149]

Chemical formula 15

[0150] In formulae (101) to (185), R has the same meaning as R in formulae (Z-1) to (Z-7). When there are a plurality of Rs, the plurality of Rs may be the same as or different from each other.

[0151] As the structural unit represented by the above formula (II), structural units represented by the following formulae (II-1) to (II-6) are preferred.

[0152]

Chemical formula 16

[0153] In formula (II-1) to formula (II-6), X 1 and X 2 Each independently represents an oxygen atom or a sulfur atom, and each independently R has the same meaning as R in formulae (Z-1) to (Z-7). When there are a plurality of R, the plurality of R may be the same as or different from each other.

[0154] From the viewpoint of easy availability of the raw material compounds, X in Formula (II-1) to Formula (II-6) 1 and X 2 A sulfur atom is preferred.

[0155] The p-type semiconductor material preferably includes a polymer compound containing a structural unit including a thiophene skeleton.

[0156] The polymer compound of the p-type semiconductor material may contain two or more structural units of the formula (I), or may contain two or more structural units of the formula (II).

[0157] In order to improve solubility in a solvent, the polymer compound of the p-type semiconductor material may contain a structural unit represented by the following formula (III).

[0158]

Chemical formula 17

[0159] In formula (III), Ar 4 It represents an arylene group. By Ar 4 The arylene group represented by means an atomic group remaining after removing two hydrogen atoms from an aromatic hydrocarbon which may have a substituent. Aromatic hydrocarbons also include compounds having a condensed ring, and compounds in which two or more selected from independent benzene rings and condensed rings are bonded directly or through a divalent group such as a vinylene group.

[0160] The arylene group has generally 6 to 60 carbon atoms, preferably 6 to 20 carbon atoms, excluding the substituent. Examples of arylene groups include phenylene groups (e.g., Formulas 1 to 3 below), naphthalene diyl groups (e.g., Formulas 4 to 13 below), anthracene diyl groups (e.g., Formulas 14 to 19 below), biphenyl diyl groups (e.g., Formulas 20 to 25 below), terphenyl diyl groups (e.g., Formulas 26 to 28 below), condensed ring compound groups (e.g., Formulas 29 to 35 below), fluorene diyl groups (e.g., Formulas 36 to 38 below), and benzofluorene diyl groups (e.g., Formulas 39 to 46 below).

[0161]

Chemical formula 18

[0162]

Chemical formula 19

[0163]

Chemical formula 20

[0164]

Chemical formula 21

[0165]

Chemical formula 22

[0166]

Chemical formula 23

[0167]

Chemical formula 24

[0168]

Chemical formula 25

[0169] In Formulae 1 to 46, R each independently has the same meaning as R in Formulae (Z-1) to (Z-7). A plurality of Rs may be the same as or different from each other.

[0170] The structural unit of the polymer compound constituting the p-type semiconductor material can also be a structural unit formed by combining and connecting two or more structural units selected from the structural unit represented by formula (I), the structural unit represented by formula (II) and the structural unit represented by formula (III).

[0171] When a polymer compound serving as a p-type semiconductor material contains at least one selected from a structural unit represented by formula (I) and a structural unit represented by formula (II), the total amount of the structural unit represented by formula (I) and the structural unit represented by formula (II) in all the structural units contained in the polymer compound (100 mol %) is generally 20 to 100 mol %, and is preferably 40 to 100 mol %, and more preferably 50 to 100 mol %, since it can improve the charge transport properties of the p-type semiconductor material.

[0172] Specific examples of polymer compounds of p-type semiconductor materials include polymer compounds represented by the following formulae P-1 to P-8. In the following formulae P-1 to P-8, n is a number greater than or equal to 1 and can be arbitrarily selected within the following weight average molecular weight range.

[0173]

Chemical formula 26

[0174]

Chemical formula 27

[0175]

Chemical formula 28

[0176] The active layer forming ink may contain only one p-type semiconductor material, or may contain two or more p-type semiconductor materials in combination at any ratio.

[0177] In particular, from the perspective of reducing the dark current ratio, the weight average molecular weight of the p-type semiconductor material converted into polystyrene is preferably greater than 40,000 and less than 200,000, more preferably greater than 40,000 and less than 150,000, and in particular from the perspective of improving solubility in solvents, it is further preferably greater than 45,000 and less than 150,000.

[0178] Here, the weight average molecular weight converted into polystyrene means a weight average molecular weight calculated using a standard sample of polystyrene by gel permeation chromatography (GPC).

[0179] -n-type semiconductor materials- The n-type semiconductor material can be a low molecular compound or a high molecular compound.

[0180] Examples of n-type semiconductor materials of low molecular weight compounds include oxadiazole derivatives; anthraquinone dimethane and its derivatives; benzoquinone and its derivatives; naphthoquinone and its derivatives; anthraquinone and its derivatives; tetracyanoanthraquinone dimethane and its derivatives; fluorenone derivatives; diphenyl dicyanoethylene and its derivatives; diphenoquinone derivatives; metal coordination compounds of 8-hydroxyquinoline and its derivatives; C 60 Fullerenes such as fullerene and their derivatives; and phenanthrene derivatives such as bathocuproin.

[0181] As other examples of n-type semiconductor materials, low molecular weight compounds having an acceptor·donor·acceptor (ADA) type structure described in Non-Patent Document 3 can also be preferably used. Non-patent literature 3: Advanced Energy Materials, 2021, Volume 11, Issue 15, Article Number 2003570

[0182] Examples of n-type semiconductor materials of polymer compounds include polyvinyl carbazole and its derivatives; polysilane and its derivatives; polysiloxane derivatives having an aromatic amine structure in the side chain or the main chain; polyaniline and its derivatives; polythiophene and its derivatives; polypyrrole and its derivatives; polyphenylene vinylene and its derivatives; polythiophene ethylene and its derivatives; polyquinoline and its derivatives; polyquinoxaline and its derivatives; and polyfluorene and its derivatives.

[0183] As the n-type semiconductor material, at least one selected from fullerene and fullerene derivatives is preferred, and a fullerene derivative is more preferred.

[0184] Examples of fullerenes include C 60 Fullerene, C 70 Fullerene, C 76Fullerene, C 78 Fullerenes and C 84 Fullerene. Examples of fullerene derivatives include derivatives of these fullerenes. Fullerene derivatives refer to compounds in which at least a part of fullerene is modified.

[0185] Examples of the fullerene derivative include compounds represented by the following formula (N-1) to formula (N-4).

[0186]

Chemical formula 29

[0187] In formula (N-1) to formula (N-4), R a Each independently represents an alkyl group, an aryl group, a monovalent heterocyclic group or a group having an ester structure. a They may be the same as or different from each other. R b Each independently represents an alkyl group or an aryl group. b They may be the same as or different from each other.

[0188] By R a Examples of the group having an ester structure represented by include a group represented by the following formula (19).

[0189]

Chemical formula 30

[0190] In formula (19), u1 represents an integer of 1 to 6. u2 represents an integer of 0 to 6. R c represents an alkyl group, an aryl group or a monovalent heterocyclic group.

[0191] As C 60 Examples of fullerene derivatives include the following compounds.

[0192]

Chemical formula 31

[0193] As C 70 Examples of fullerene derivatives include the following compounds.

[0194]

Chemical formula 32

[0195] Specific examples of fullerene derivatives include [6,6]-phenyl-C61 butyric acid methyl ester (C60PCBM, [6,6]-Phenyl C61 butyric acid methyl ester), [6,6]-phenyl-C71 butyric acid methyl ester (C70PCBM, [6,6]-Phenyl C71 butyric acid methyl ester), [6,6]-phenyl-C85 butyric acid methyl ester (C84PCBM, [6,6]-Phenyl C85butyric acid methyl ester), and [6,6]-thienyl-C61 butyric acid methyl ester ([6,6]-ThienylC61 butyric acid methyl ester).

[0196] The active layer forming ink may contain only one n-type semiconductor material, or may contain two or more n-type semiconductor materials in combination at any ratio.

[0197] -Solvents- The active layer forming ink preferably contains a solvent. The solvent preferably contains a first solvent and, if necessary, a second solvent.

[0198] ·1st solvent The first solvent may be selected in consideration of the solubility of the selected p-type semiconductor material and n-type semiconductor material and the characteristics (boiling point, etc.) for coping with the drying conditions when forming the active layer. The first solvent is an aromatic hydrocarbon (hereinafter referred to as an aromatic hydrocarbon) which may have a substituent (eg, an alkyl group or a halogen atom). The first solvent is preferably selected in consideration of the solubility of the selected p-type semiconductor material and n-type semiconductor material.

[0199] As the aromatic hydrocarbons, for example, toluene, xylene (e.g., o-xylene, m-xylene, p-xylene), trimethylbenzene (e.g., mesitylene, 1,2,4-trimethylbenzene (trimethylbenzene)), butylbenzene (e.g., n-butylbenzene, sec-butylbenzene, tert-butylbenzene), methylnaphthalene (e.g., 1-methylnaphthalene), tetralin, indane, chlorobenzene and dichlorobenzene (e.g., o-dichlorobenzene) can be cited.

[0200] The first solvent preferably contains one or more selected from toluene, o-xylene, m-xylene, p-xylene, mesitylene, unimolecular trimethylolbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methylnaphthalene, tetralin, indane, chlorobenzene and o-dichlorobenzene, and more preferably contains o-xylene, unimolecular trimethylolbenzene, tetralin, chlorobenzene or o-dichlorobenzene.

[0201] The first solvent may be composed of only one kind of aromatic hydrocarbon or may be composed of two or more kinds of aromatic hydrocarbons. The first solvent is preferably composed of only one kind of aromatic hydrocarbon.

[0202] · Second solvent The second solvent is a solvent selected from the viewpoint of improving the solubility of the n-type semiconductor material. Examples of the second solvent include ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone, and propiophenone; ester solvents such as ethyl acetate, butyl acetate, phenyl acetate, ethyl cellosolve acetate, methyl benzoate, butyl benzoate, and benzyl benzoate; and ether solvents such as anisole and o-dimethoxybenzene. The second solvent is preferably acetophenone, propiophenone or benzyl benzoate.

[0203] Combination of the first solvent and the second solvent Examples of the combination of the first solvent and the second solvent include the combinations shown in Table 1 below.

[0204]

Table 1

[0205] · Weight ratio of the first solvent to the second solvent From the viewpoint of further improving the solubility of the p-type semiconductor material and the n-type semiconductor material, the mass ratio of the first solvent to the second solvent (first solvent / second solvent) is preferably in the range of 85 / 15 to 97 / 3.

[0206] · Mass percentage of the total amount of the first solvent and the second solvent in the active layer forming ink From the viewpoint of further improving the solubility of p-type semiconductor materials and n-type semiconductor materials, when the total weight of the ink for forming the active layer is set to 100 mass %, the total mass of the first solvent and the second solvent contained in the ink for forming the active layer is preferably greater than 90 mass % and less than 97.5 mass %.

[0207] -Other ingredients- The active layer forming ink may further contain components other than the p-type semiconductor material, the n-type semiconductor material, and the solvent. Examples of other components include ultraviolet absorbers, antioxidants, sensitizers for sensitizing the function of generating electric charges by absorbed light, and light stabilizers for increasing stability against ultraviolet rays.

[0208] (Step of forming a second intermediate layer or intermediate layer-2) In this step, a second intermediate layer or an intermediate layer is formed on the active layer. In this step, when the second intermediate layer is formed, the step of forming the second intermediate layer is carried out in the same manner as in the "-Step of forming the second intermediate layer-" in the above-mentioned (Step of forming the second intermediate layer or intermediate layer-1). In this step, when the intermediate layer is formed, the step of forming the intermediate layer is carried out in the same manner as in the "-Step of forming the intermediate layer-" in the above-mentioned (Step of forming the second intermediate layer or the intermediate layer-1).

[0209] (Step of forming an electrode on the second intermediate layer or the intermediate layer) The method for forming the electrode on the second intermediate layer or the intermediate layer is not particularly limited. The electrode can be formed on the supporting substrate by vacuum deposition, sputtering, ion plating, plating, or the like. Examples of the material for the electrode include the compounds exemplified as the material for the electrode described above. [Example]

[0210] Examples are described below, but the present invention is not limited to these Examples. In the following description, "parts" and "%" are based on mass unless otherwise specified.

[0211] <Materials> The p-type semiconductor material, n-type semiconductor material, nonionic insulating polymer, ionic polymer, and inorganic buffer material used in the following Examples and Comparative Examples are as follows.

[0212] (p-type semiconductor material) As the p-type semiconductor material, the polymer compounds represented by the above-mentioned formula P-7 and formula P-8 are used. The polymer compound represented by the formula P-7 was synthesized and used with reference to the method described in International Publication No. 2013 / 051676. The polymer compound represented by the formula P-8 was synthesized and used with reference to the method described in International Publication No. 2011 / 052709.

[0213] (n-type semiconductor material) As the n-type semiconductor material N-1, Guard Surf NC-1010 manufactured by HARVES Corporation was used.

[0214] (Non-ionic insulating polymer) The following Z-1 to Z-8 were used as the nonionic insulating polymer. Table 4 shows the glass transition temperatures and melting points of the nonionic insulating polymers. ·Z-1: Polyimide, manufactured by Kawamura Industry Co., Ltd., trade name: KPI-MX300F ·Z-2: Polycarbonate, manufactured by Scientific Polymer Products Z-3: Polymethyl methacrylate, manufactured by Scientific Polymer Products ·Z-5: Cellulose acetate, manufactured by Scientific Polymer Products ·Z-6: Polyphenylene ether sulfone, Scientific Polymer Products Z-7: Polytetrafluoroethylene, manufactured by Scientific Polymer Products ·Z-8: Fluoropolymer, manufactured by AGC Corporation, trade name: CYTOP CTL-809M

[0215] (Ionic polymer) The following I-1 to I-3 were used as the ionic polymer. I-1: Polyethyleneimine derivative, manufactured by Sigma-Aldrich, trade name: Polyethyleneimine, 80% ethoxylated solution ·I-2: PFN-Br, manufactured by Ossila Corporation ·I-3: Polyvinylpyrrolidone, Scientific Polymer Products

[0216] The structural formulas of Z-2 to Z-3, Z-5 to Z-8, and I-1 to I-3 are shown below.

[0217]

Chemical formula 33

[0218] (Inorganic materials) As the inorganic material, the following M-1 was used. M-1: Tayca, zinc oxide nanoparticle dispersion (HTD-711Z)

[0219] <Band Gap Calculation> The band gap can be calculated using the light absorption edge wavelength of the nonionic insulating polymer by the following formula: Where Eg represents the band gap and h represents the Planck constant (6.626×10 -34 Js), c represents the speed of light (3×10 8 m / s). Formula: Eg = hc / absorption edge wavelength

[0220] In the above formula, the absorption edge wavelength is determined by using a spectrophotometer (Ultraviolet-visible-near-infrared spectrophotometer JASCO-V670 manufactured by JASCO Corporation) that can measure in the wavelength region of ultraviolet light, visible light, and near-infrared light. In the absorption spectrum obtained by the spectrophotometer, that is, the absorption spectrum plotted by setting the vertical axis to the absorbance (absorption intensity) of the (polymer) compound and the horizontal axis to the wavelength, the absorption edge wavelength can be the value of the wavelength at the intersection of the baseline and the shoulder (high wavelength side) of the absorption peak fitted as the absorption edge wavelength (nm). The band gaps of Z-1, Z-2, Z-3, Z-5, Z-6, Z-7 and Z-8 are all in the range of 3.5 to 3.8 eV.

[0221] <Preparation of specific ink> A nonionic insulating polymer or an ionic polymer and a solvent were mixed at the mixing ratios shown in Table 2 to prepare specific inks BI-1 to BI-3 and BI-5 to BI-11. The amounts of Z-8 and I-1 added shown in Table 2 are the amounts of the polymer solution of Z-8 diluted with a solvent (the solvent is the same as the solvent contained in the specific ink) and the polymer solution of I-1 diluted with a solvent. The concentration of the polymer solution of BI-8 using Z-8 was 0.45% by mass, and the concentration of the polymer solution of BI-9 using I-1 was 3.5 to 4% by mass based on the standard value of the product of I-1.

[0222]

Table 2

[0223] In Table 2, BS-1 to BS-5 are as follows. BS-1: 2,2,3,3,4,4,5,5-octafluoro-1-pentanol BS-2: γ-Butyrolactone BS-3: 3-pentanol BS-4: 2-Methoxyethanol BS-5: Fluorinated solvent, manufactured by AGC, trade name: CT-SOLV180

[0224] <Preparation of Active Layer Forming Ink> The p-type semiconductor material, the n-type semiconductor material, the first solvent, and the second solvent were mixed at the mixing ratio described in Table 3 to prepare active layer forming inks AI-1 and AI-2.

[0225]

Table 3

[0226] In Table 3, AS-1 to AS-4 are as follows. ·AS-1: Tetralin ·AS-2: Butyl benzoate ·AS-3: Trimethylol ·AS-4: o-Dimethoxybenzene

[0227] <Example 1> According to the following steps, for a photoelectric conversion element having a structure in which a supporting substrate, an electrode, an active layer, an intermediate layer, and an electrode are stacked in this order, both a photoelectric conversion element that is not heat-treated before sealing and a photoelectric conversion element that is sealed after heat treatment are prepared. A photoelectric conversion element that was not subjected to heat treatment before sealing was produced by the following steps (1) to (5). Hereinafter, this element is referred to as a photoelectric conversion element without heat treatment. After the following steps (1) to (4), heat treatment is performed for 10 minutes on a hot plate heated to 200°C in a nitrogen atmosphere, and then sealing is performed in step (5) to produce a photoelectric conversion element sealed after heat treatment. Hereinafter, this element is referred to as a photoelectric conversion element after heat treatment.

[0228] (1) Step of forming electrodes on a substrate An ITO thin film was formed as an electrode with a thickness of 45 nm on a glass substrate serving as a supporting substrate by sputtering, and the surface of the glass substrate was subjected to ozone UV treatment.

[0229] (2) Step of forming active layer Then, a coating film of active layer forming ink AI-1 was formed on the ITO thin film by spin coating, and then heated at 70°C for 5 minutes on a hot plate in the air, and then dried by heating for 10 minutes on a hot plate heated to 100°C in a nitrogen atmosphere to form an active layer. The thickness of the formed active layer was about 250 nm.

[0230] (3) Step of forming a second intermediate layer or intermediate layer-2 In this step, an intermediate layer is formed on the active layer. The specific ink BI-1 is used to form a coating film of the intermediate layer on the active layer by spin coating. The thickness of the formed intermediate layer is 6 nm.

[0231] (4) Step of forming an electrode on the second intermediate layer or the intermediate layer Then, an ITO film as an electrode was formed on the intermediate layer with a thickness of about 50 nm using a sputtering device to form a photoelectric conversion element. The planar shape of the obtained photoelectric conversion element when viewed in the thickness direction was a square of 2 mm×2 mm.

[0232] (5) Other processes Then, after applying an ultraviolet (UV) curable sealant on the sealing glass substrate, the sealing glass substrate is bonded to the glass substrate on which the photoelectric conversion element is formed, and irradiated with UV light to obtain a sealed photoelectric conversion element.

[0233] <Examples 2 to 7, Comparative Examples 1 to 3> A sealed photoelectric conversion element was obtained by following the same steps as in Example 1, except that the type of active layer forming ink in (process of forming active layer) and the type of specific ink in (process of forming second intermediate layer or intermediate layer-2) were changed as shown in Table 4.

[0234] <Comparative Example 4> The intermediate layer is formed by performing the following steps (step 2 of forming the second intermediate layer or the intermediate layer). A solution of the inorganic material M-1 diluted 10 times with 3-pentanol was prepared, and a coating film of an intermediate layer composed of the inorganic material M-1 was formed on the active layer by spin coating. The thickness of the formed intermediate layer was 40 nm. The subsequent steps were carried out in the same manner as in Example 1 (step of forming an electrode on the second intermediate layer or the intermediate layer) to obtain a sealed photoelectric conversion element.

[0235] <Evaluation> (Dark current density Jd) For the photoelectric conversion element without heat treatment obtained in each example and the photoelectric conversion element with heat treatment obtained in each example, current-voltage measurement was performed using a source meter (KEITHLEY2611B Source Meter, manufactured by Keithley Instruments) in a dark state without light irradiation, and the value of dark current density Jd when the reverse bias voltage was 5V was obtained. Table 4 shows the absolute values ​​of the dark current density Jd of the photoelectric conversion element without heat treatment and the photoelectric conversion element with heat treatment. Evaluation was performed according to the following evaluation criteria based on the absolute value of the dark current density Jd of the photoelectric conversion element subjected to the heat treatment. -Evaluation Criteria- A: The absolute value of the dark current density Jd of the photoelectric conversion element after heat treatment is less than 200 B: The absolute value of the dark current density Jd of the photoelectric conversion element after heat treatment is greater than 200 and less than 500 C: The absolute value of the dark current density Jd of the photoelectric conversion element after heat treatment is greater than 500

[0236] (Ratio of detection capability D * ) Known ratio detection capability D *It can be approximately calculated as shown in the following formula 1. Formula 1: D * =SR / (2×elementary charge×Jd) 0.5 Here, SR is spectral sensitivity (unit: A / W, ampere / watt). SR was obtained as follows. Using a spectrophotometric sensitivity measuring device CEP-25ML manufactured by Spectrometer Co., Ltd., the value of the photocurrent JL when the reverse bias voltage was 5V was obtained under the state of irradiation with light. The amount of light of the irradiated light is the number of photons 1E+14. In the case of active layer forming ink AI-1, the photocurrent value at a wavelength of 940nm was used, and in the case of active layer forming ink AI-2, the photocurrent value at a wavelength of 800nm ​​was used, and it was calculated as described in the following formula 2. Formula 2: SR = (JL-Jd) / (Energy of irradiated light) Here, in Formula 1 and Formula 2, Jd is the absolute value of the dark current density Jd of the photoelectric conversion element without heat treatment or the absolute value of the dark current density Jd of the photoelectric conversion element with heat treatment. * When the absolute value of the dark current density Jd of the photoelectric conversion element without heat treatment is substituted into equations 1 and 2. In addition, the specific detection capability D of the photoelectric conversion element with heat treatment is calculated. * When , the absolute value of the dark current density Jd of the photoelectric conversion element that has been heat treated is substituted into Formula 1 and Formula 2. The relative detection capability D of the photoelectric conversion element without heat treatment and the photoelectric conversion element with heat treatment * The absolute values ​​are shown in Table 4. Specific detection capability D based on the photoelectric conversion element with heat treatment * The absolute value of was evaluated using the following evaluation criteria. -Evaluation Criteria- A: Detection capability of heat-treated photoelectric conversion element D * The exponent of the value is 13 B: Detection capability of heat-treated photoelectric conversion element D * The exponent of the value is 12 C: Detection capability of heat-treated photoelectric conversion element D * The exponent of the value is 11 Here, the "index part" refers to: D with heat treatment in Table 4 * The value recorded on the right side of "E+" in the value.

[0237]

Table 4

[0238] In Table 4, D without heat treatment * and heat treated D * The value of is expressed as an exponent. In Table 4, the expressions described below the glass transition temperature and melting point are explained as follows. ·“-”: indicates not determined. ·“>”: Indicates that the glass transition temperature or melting point is greater than the value described on the right side of the “>”. "ND": Not Detected. From the above results, it can be seen that the photoelectric conversion element of this example can suppress the increase of dark current after heating.

Claims

1. A photoelectric conversion element, characterized in that: have anode, cathode, an active layer disposed between the anode and the cathode, at least one intermediate layer disposed between the anode and the active layer and between the cathode and the active layer, The intermediate layer contains a nonionic insulating polymer.

2. The photoelectric conversion element according to claim 1, wherein The nonionic insulating polymer has a glass transition temperature of 100° C. or higher.

3. The photoelectric conversion element according to claim 1, wherein The nonionic insulating polymer has a melting point of 150° C. or higher.

4. The photoelectric conversion element according to claim 1, wherein The nonionic insulating polymer is at least one selected from the group consisting of poly(meth)acrylic acid, polycarbonate, polyimide and fluorine-containing polymer.

5. The photoelectric conversion element according to claim 1, wherein The nonionic insulating polymer is polyimide.

6. The photoelectric conversion element according to claim 1, wherein An intermediate layer is provided between the cathode and the active layer.

7. The photoelectric conversion element according to claim 6, wherein The cathode is a transparent or semi-transparent electrode.

8. The photoelectric conversion element according to claim 1, wherein The active layer contains a p-type semiconductor material.

9. The photoelectric conversion element according to claim 8, wherein The p-type semiconductor material is a polymer compound containing at least one selected from the group consisting of a structural unit represented by the following formula (I) and a structural unit represented by the following formula (II). In formula (I), Z represents any one of formulas (Z-1) to (Z-7), Ar 1 and Ar 2 represents the same or different trivalent aromatic heterocyclic groups; in formula (II), Ar 3 represents a divalent aromatic heterocyclic group; in the formulae (Z-1) to (Z-7), R each independently represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkenyl group which may have a substituent, a cycloalkenyl group which may have a substituent, an alkynyl group which may have a substituent, a cycloalkynyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, a cycloalkyloxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylthio group which may have a substituent, a cycloalkylthio group which may have a substituent, an arylthio group which may have a substituent, a monovalent heterocyclic group which may have a substituent, a substituted amino group which may have a substituent, an imine residue which may have a substituent, an amide group which may have a substituent, an imide group which may have a substituent, a substituted oxycarbonyl group which may have a substituent, a cyano group, a nitro group, a -C(=O)-R c A group represented by -SO2-R d The group represented by R c and R d Each independently represents a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, a cycloalkyloxy group which may have a substituent, an aryloxy group which may have a substituent, or a monovalent heterocyclic group which may have a substituent; when there are multiple Rs, the multiple Rs may be the same as or different from each other.

10. The photoelectric conversion element according to claim 1, wherein The thickness of the intermediate layer is greater than or equal to 1 nm and less than or equal to 20 nm.

11. An ink for making a photoelectric conversion element, characterized in that: Contains non-ionic insulating polymer.

12. A method for manufacturing a photoelectric conversion element, characterized in that: The method comprises the steps of forming a coating film by coating an ink containing a nonionic insulating polymer, and drying the coating film.

13. The photoelectric conversion element according to any one of claims 1 to 10, characterized in that It is a light detecting element.

14. An image sensor, characterized in that: A photoelectric conversion element according to claim 13 is included.

15. A fingerprint authentication device, characterized in that: A photoelectric conversion element according to claim 13 is included.

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