Compounds, compounds for photoelectric conversion elements, photoelectric conversion elements, electronic equipment, and power supply modules

Abstract

To provide a compound that has a high absorbance and a broad absorption wavelength and can serve solely as an absorption dye.SOLUTION: The present invention provides a compound represented by the following formula (where R1 and R2 each represent a C4-12 linear or branched alkyl group, and X represents the following structure or the like).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to compounds, compounds for photoelectric conversion elements, photoelectric conversion elements, electronic devices, and power supply modules. [Background technology]

[0002] In recent years, solar cells, which can efficiently generate electricity even in low light conditions, have attracted considerable attention. They are not only versatile in terms of installation location, but are also expected to have a wide range of applications as self-contained power sources that do not require battery replacement or power wiring.

[0003] Amorphous silicon and organic solar cells are known as photoelectric conversion elements for indoor use. Among organic solar cells, dye-sensitized solar cells have the advantage of being easy to fabricate because they are composed of layers that separate charge generation and charge transport functions. Generally, dye-sensitized solar cells have problems such as evaporation and leakage of the electrolyte that is contained within them, but in recent years, solid-state dye-sensitized solar cells using P-type semiconductor materials have been developed and are attracting attention.

[0004] More specifically, for example, a photoelectric conversion element has been proposed that can suppress voltage drop and obtain high output even in high-temperature environments or in environments with weak indoor light (see, for example, Patent Document 1). [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a compound that has high absorbance and a wide absorption wavelength range, and can be used as an absorption dye with only one compound. [Means for solving the problem]

[0006] The compound of the present invention, as a means to solve the above problems, is a compound represented by the following general formula (1). [ka] ···General formula (1) (In general formula (1), R1 and R2 represent a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents any of the following structures.)

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a compound having a large absorbance, a wide absorption wavelength range, and capable of being used as a single absorption dye.

Brief Description of the Drawings

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of a photoelectric conversion element of the first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an example of a photoelectric conversion element of the second embodiment. [Figure 3] FIG. 3 is a schematic diagram showing an example of a photoelectric conversion element of the third embodiment. [Figure 4] FIG. 4 is a schematic diagram showing an example of a photoelectric conversion module of the fourth embodiment. [Figure 5] FIG. 5 is a schematic diagram showing an example of a photoelectric conversion module of the fifth embodiment. [Figure 6] FIG. 6 is a block diagram of a mouse for a personal computer as an example of an electronic device of the present invention. [Figure 7] FIG. 7 is a schematic external view showing an example of the mouse shown in FIG. 6. [Figure 8] FIG. 8 is a block diagram of a keyboard for a personal computer as an example of an electronic device of the present invention. [Figure 9] Figure 9 is a schematic external view showing an example of the keyboard shown in Figure 8. [Figure 10] Figure 10 is a schematic external view showing another example of the keyboard shown in Figure 8. [Figure 11] Figure 11 is a block diagram of a sensor as an example of the electronic device of the present invention. [Figure 12] Figure 12 is a block diagram of a turntable as an example of the electronic device of the present invention. [Figure 13] Figure 13 is a block diagram showing an example of the electronic device of the present invention. [Figure 14] Figure 14 is a block diagram showing an example in which a power supply IC is further incorporated into the electronic device shown in Figure 13. [Figure 15] Figure 15 is a block diagram showing an example in which an energy storage device is further incorporated into the electronic device shown in Figure 14. [Figure 16] Figure 16 is a block diagram showing an example of the power supply module of the present invention. [Figure 17] Figure 17 is a block diagram showing an example in which an energy storage device is further incorporated into the power supply module shown in Figure 16. [Figure 18] Figure 18 shows an example of an X-ray absorption fine structure (XAFS) spectrum measured using the photoelectric conversion element of Example 1. [Figure 19A] Figure 19A shows the FT-IR spectrum of the photosensitized compound used in Example 1. [Figure 19B] Figure 19B shows the molar extinction coefficient of the photosensitizing compound used in Example 1. [Modes for carrying out the invention]

[0009] (compound) The compound of the present invention is represented by the following general formula (1). [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka]

[0010] Through diligent research, the inventors discovered a compound represented by the above general formula (1) that has high absorbance and a wide absorption wavelength range, and can be used as an absorption dye with only one compound, thus completing the technology of the present invention. If the compound of the present invention is the compound represented by the above general formula (1), it has a high absorbance and a wide absorption wavelength range. In the prior art, it was necessary to mix two or more dye compounds having different absorption wavelength ranges in order to broaden the absorption wavelength range. However, we have found that the compound represented by the above general formula (1) can be used as an absorbent dye with only one compound.

[0011] [Method for producing compounds represented by general formula (1)] The compound represented by the general formula (1) can be produced, for example, using the raw materials 1 and 2 listed below, by referring to the method described in J.Am.Chem.Soc.2016,138,10742-10745. The compound represented by raw material 1 can be produced, for example, by referring to the method described in J.Mater.Chem.,2009,19,4715-4724. Furthermore, the compound represented by raw material 2 can be manufactured, for example, by referring to the method described in Polymers for Advanced Technologies (2018), 29(3), 1170-1181.

[0012] [ka] ...Ingredients 1

[0013] [ka] ...Ingredients 2

[0014] The compound represented by the general formula (1) can be produced, for example, using the following raw materials 1 and 2, by referring to the method described in J.Am.Chem.Soc.2016,138,10742-10745, as follows.

[0015] [ka]

[0016] [ka]

[0017] [ka]

[0018] [ka]

[0019] Furthermore, it is preferable that the general formula (1) is a compound represented by the following general formula (2). [ka] ...General formula (2) (In general formula (2), R2 represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka]

[0020] [Method for synthesizing compounds represented by general formula (2)] The compound represented by the general formula (2) can, for example, be produced using the raw material 2 and the raw material 3 described below, by referring to the method described in J.Am.Chem.Soc.2016,138,10742-10745. The compound represented by raw material 3 can be produced, for example, by referring to the method described in J.Mater.Chem.,2009,19,4715-4724.

[0021] [ka] ...Ingredients 3 The compound represented by raw material 3 can be produced, for example, by referring to the method described in J.Mater.Chem.,2009,19,4715-4724.

[0022] The compound represented by the general formula (2) can be produced, for example, using raw materials 2 and 3 below, by referring to the method described in J.Am.Chem.Soc.2016,138,10742-10745, as follows.

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] [ka]

[0027] Compounds represented by general formulas (1) and (2) can be identified as follows. [Method for identifying compounds represented by general formulas (1) and (2)] It can be identified using triple quadrupole mass spectrometers (MS / MS: TSQ Fortis) manufactured by Thermo Fisher Scientific, Inc., or Fourier transform infrared spectrophotometers (FT-IR: IRSpirit) manufactured by Shimadzu Corporation, etc.

[0028] The following are specific example compounds represented by general formulas (1) and (2), but the present invention is not limited to these. [ka] (B1-1) [ka] (B1-2) [ka] (B1-3) [ka] (B1-4) [ka] (B1-5) [ka] (B1-6) [ka] (B1-7) [ka] (B1-8) [ka] (B1-9)

[0029] The compounds represented by (B1-1) to (B1-9) above can be synthesized, for example, as follows. An example of synthesizing compound (B1-6) is shown below.

[0030] [Synthesis method for compounds represented by (B1-6)] <Synthesis example of raw material 1 1a> [ka] 4-Iodoaniline, 1-Iodooctane, sodium carbonate, and anhydrous dimethylformamide are placed in a 500 ml four-necked flask and heated and stirred at 120°C for 7 hours. The organic phase is then washed with water, extracted, and concentrated. Subsequently, column purification is performed using dichloromethane. The obtained compound is placed in a 200 ml four-necked flask with trimethylsilylacetylene, CuI, and diisopropylamine. Palladium-tetrakis(triphenylphosphine) (Pd(PPh3)4) is added under an argon gas atmosphere, and the mixture is heated and stirred at 50°C for 3 hours. The organic phase is then washed with water, extracted, and concentrated. Subsequently, methanol, dichloromethane, and sodium hydroxide are added, and the mixture is stirred at room temperature for 2 hours. The organic phase is then washed with water, extracted, and concentrated.

[0031] <Synthesis example 1b of raw material 2> [ka] 4,4-bis(2-ethylhexyl)-4H-cyclopenta-dithiophene is dissolved in anhydrous tetrahydrofuran and stirred at -78°C under an argon gas atmosphere. Next, add 1.55 M n-butyllithium hexane and stir at -78°C for 3 hours. Then, slowly add a solution of tributyltin chloride diluted in anhydrous tetrahydrofuran dropwise. The mixture is stirred at -78°C for 1 hour, then stirred at room temperature for 1 hour, and the organic phase is washed with water, extracted, and concentrated.

[0032] <Synthesis example 1c> [ka] Place 4,7-dibromo-2,1,3-benzothiazole, 4-formylphenylbenzoic acid, potassium carbonate, tetrahydrofuran, and water into a 200 ml four-necked flask and stir under an argon gas atmosphere. Pd(PPh3)4 is added, and the mixture is heated and stirred at 50°C for 10 hours. The organic phase is then washed with water, extracted, and concentrated.

[0033] <Synthesis Example 1d> [ka] The aldehyde obtained in Synthesis Example 1c, Pd(PPh3)2Cl2, and toluene are placed in a 200 ml four-necked flask and heated and stirred at 40°C under an argon gas atmosphere. Next, the tin compound obtained in synthesis example 1b of raw material 2, along with a toluene solution, is added dropwise, and reflux stirring is carried out for 2 hours. The organic phase is then washed with water, extracted, and concentrated. Dissolve in dichloromethane, stir at 3°C, add NBS, and stir for 4 hours. Wash and extract the organic phase with water and concentrate.

[0034] <Synthesis Example 1e> [ka] The acetylene compound obtained in Synthesis Example 1a of Raw Material 1, the bromo compound obtained in Synthesis Example 1d, tetrahydrofuran, triethylamine, and CuI are placed in a 100 ml four-necked flask and stirred under an argon gas atmosphere. Pd(PPh3)4 is added, and reflux stirring is carried out for 1 hour. The organic phase is then washed with water, extracted, and concentrated. Column purification (dichloromethane / cyclohexane = 7 vol / 3 vol) is performed, followed by further purification using recycled GPC. The entire purified product, cyanoacetic acid, ammonium acetate, and acetic acid are placed in a 100 ml four-necked flask, and reflux stirring is carried out for 2 hours. The organic phase is then washed with water, extracted, and concentrated. Column purification (dichloromethane / methanol = 8 vol / 2 vol) is performed, followed by dissolution in dichloromethane and reprecipitation with methanol. The purified product is dried to obtain the compound represented by (B1-6).

[0035] The absorbance of the compounds represented by (B1-1) to (B1-9) above can be measured by the following method. For example, a 0.2 mM acetonitrile / tert-butanol (1 / 1 vol) dye solution can be diluted, and its absorbance (abs) can be measured using a UV-Vis spectrophotometer (device name: UV-3600, manufactured by Shimadzu Corporation) to calculate the molar extinction coefficient. As an example, Figure 19B shows the molar extinction coefficient of the compound represented by (B1-6).

[0036] The compounds of the present invention have high absorbance and a wide absorption wavelength range, and can be used as an absorption dye with only one compound. Furthermore, the compounds of the present invention are photoexcited by irradiated light and can obtain high output in solid-state dye-sensitized solar cells, making them particularly suitable for use as photoelectric conversion elements.

[0037] (Compounds for photoelectric conversion elements) The compound for photoelectric conversion elements of the present invention is a compound represented by the following general formula (1). [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka]

[0038] The compound for the photoelectric conversion element of the present invention is the same as the compound of the present invention.

[0039] (Photoelectric conversion element) The photoelectric conversion element of the present invention is First electrode and, An electron transport layer containing a compound represented by the following general formula (1), Hall transport layer, It has a second electrode and, if necessary, other layers. [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka]

[0040] Conventional technology had the problem of output degradation after exposure to high-intensity light environments. Furthermore, in conventional technology, the dye compounds used in the photoelectric conversion elements exhibited a reddish color, which made the color of the photoelectric conversion elements stand out and conspicuous, making them difficult to use in indoor applications.

[0041] The inventors of the present invention have found that, in the prior art, it was necessary to mix two or more dye compounds (photosensitizing compounds) having different absorption wavelength ranges in order to broaden the absorption wavelength range, but a single compound represented by the above general formula (1) has a sufficient absorption wavelength range and can be practically used as an absorbing dye. Furthermore, the present inventors have found that a photoelectric conversion element having an electron transport layer containing the compound represented by the above general formula (1) can suppress the decrease in output at low light levels after being exposed to a high-light environment.

[0042] In this specification, "photoelectric conversion element" means an element that converts light energy into electrical energy, or an element that converts electrical energy into light energy, and specifically includes solar cells and photodiodes. In this invention, the term "layer" includes not only a structure in which multiple films are stacked on top of each other, but also a single film (monolayer). Furthermore, the stacking direction refers to the direction perpendicular to the plane direction of each layer in the photoelectric conversion element. Also, connection refers not only to physical contact but also to an electrical connection sufficient to achieve the effects of the present invention. The photoelectric conversion element of the present invention comprises a first electrode, a photoelectric conversion layer, and a second electrode, wherein the photoelectric conversion layer has at least a hole transport layer, and optionally includes other members such as a first substrate, a second substrate, a hole blocking layer, and a sealing member.

[0043] <First substrate> The shape, structure, and size of the first substrate are not particularly limited and can be appropriately selected according to the purpose. The material of the first substrate is not particularly limited as long as it has light-transmitting and insulating properties, and can be appropriately selected according to the purpose. Examples include glass, plastic film, and ceramic substrates. Among these, if the process includes firing when forming the electron transport layer, as will be described later, a substrate that has heat resistance to the firing temperature is preferred. Furthermore, a flexible first substrate is more preferable.

[0044] The substrate may be provided on either the outermost side of the first electrode and / or the outermost side of the second electrode of the photoelectric conversion element, or both. Hereinafter, the substrate provided on the outermost side of the first electrode will be referred to as the first substrate, and the substrate provided on the outermost side of the second electrode will be referred to as the second substrate.

[0045] <First electrode> The shape and size of the first electrode are not particularly limited and can be appropriately selected according to the purpose. The structure of the first electrode is not particularly limited and can be appropriately selected depending on the purpose. It may be a single-layer structure or a structure in which multiple materials are stacked. The material of the first electrode is not particularly limited as long as it has transparency and conductivity to visible light, and can be appropriately selected depending on the purpose. Examples include transparent conductive metal oxides, carbon, and metals.

[0046] Examples of the transparent conductive metal oxides include indium tin oxide (hereinafter referred to as "ITO"), fluorine-doped tin oxide (hereinafter referred to as "FTO"), antimond-doped tin oxide (hereinafter referred to as "ATO"), niobium-doped tin oxide (hereinafter referred to as "NTO"), aluminum-doped zinc oxide, indium zinc oxide, and niobium titanium oxide. Examples of the aforementioned carbon include carbon black, carbon nanotubes, graphene, and fullerene. Examples of the aforementioned metals include gold, silver, aluminum, nickel, indium, tantalum, and titanium. These may be used individually or in combination of two or more. Among these, transparent conductive metal oxides with high transparency are preferred, with ITO, FTO, ATO, and NTO being more preferred.

[0047] There are no particular restrictions on the average thickness of the first electrode, and it can be appropriately selected depending on the purpose, but it is preferably 5 nm to 100 μm, and more preferably 50 nm to 10 μm. In the case where the material of the first electrode is carbon or metal, it is preferable that the average thickness of the first electrode be such that light transmission can be obtained.

[0048] The first electrode can be formed by known methods such as sputtering, vapor deposition, or spraying.

[0049] Furthermore, the first electrode is preferably formed on the first substrate, and a commercially available integrated product in which the first electrode is already formed on the first substrate can be used. Examples of the integrated commercial products include FTO-coated glass, ITO-coated glass, zinc oxide:aluminum-coated glass, FTO-coated transparent plastic film, and ITO-coated transparent plastic film. Other examples of the integrated commercial products include transparent electrodes doped with tin oxide or indium oxide with cations or anions of different valencies, or glass substrates equipped with metal electrodes that have a light-transmitting structure such as a mesh or stripe. These can be used individually, or two or more can be mixed or layered together. Furthermore, metal lead wires may be used in combination to reduce electrical resistance.

[0050] Examples of materials for the aforementioned metal lead wires include aluminum, copper, silver, gold, platinum, and nickel. The aforementioned metal lead wires can be used in combination by, for example, forming them on a substrate by vapor deposition, sputtering, or crimping, and then providing a layer of ITO or FTO on top of them.

[0051] <Photoelectric conversion layer> The photoelectric conversion layer comprises a hole blocking layer, an electron transport layer, and another hole transport layer, and further comprises other layers as necessary. The photoelectric conversion layer may be a single layer or a multilayer in which multiple layers are stacked.

[0052] <<Whole Blocking Layer>> The hole blocking layer is preferably formed between the first electrode and the electron transport layer. In other words, in the present invention, it is preferable to further have the hole blocking layer between the first electrode and the photoelectric conversion layer. The aforementioned hole-blocking layer is highly effective in improving output and its sustainability. The hole blocking layer, for example, is generated by the photosensitizing compound and can transport electrons transported to the electron transport layer to the first electrode, while preventing contact with the hole transport layer. As a result, the hole blocking layer makes it difficult for holes to flow into the first electrode, and can suppress the decrease in output due to the recombination of electrons and holes. In solid-state photoelectric conversion elements provided with the hole transport layer, the recombination rate between holes in the hole transport material and electrons on the electrode surface is faster than in wet-type photoelectric conversion elements using an electrolyte, so the effect of forming the hole blocking layer is very significant.

[0053] The material of the hole blocking layer is not particularly limited as long as it is transparent to visible light and has electron transport properties, and can be appropriately selected according to the purpose. Examples include elemental semiconductors such as silicon and germanium, compound semiconductors represented by metal chalcogenides, and compounds having a perovskite structure.

[0054] Examples of the aforementioned metal chalcogenides include oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum; sulfides of cadmium, zinc, lead, silver, antimony, and bismuth; selenides of cadmium and lead; and tellurides of cadmium. Examples of other compound semiconductors include phosphides of zinc, gallium, indium, and cadmium; gallium arsenide, copper-indium selenide, and copper-indium sulfide. Examples of compounds having the perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate. Among these, oxide semiconductors are preferred, with titanium oxide, niobium oxide, magnesium oxide, aluminum oxide, zinc oxide, tungsten oxide, and tin oxide being more preferred, and titanium oxide being even more preferred. These materials may be used individually or in combination of two or more. They may also be used as single layers or stacked layers. Furthermore, there are no particular restrictions on the crystal type of these semiconductors; they can be appropriately selected according to the purpose, and may be single crystals, polycrystalline, or amorphous.

[0055] There are no particular restrictions on the method for fabricating the hole blocking layer, and it can be appropriately selected depending on the purpose. Examples include a method for forming a thin film in a vacuum (vacuum deposition method) and a wet deposition method. Examples of the aforementioned vacuum film deposition methods include sputtering, pulsed laser deposition (PLD), ion beam sputtering, ion-assisted deposition, ion plating, vacuum evaporation, atomic layer deposition (ALD), and chemical vapor deposition (CVD). Examples of the aforementioned wet film-forming methods include the sol-gel method. The sol-gel method is a method in which a gel is prepared from a solution through chemical reactions such as hydrolysis, polymerization, and condensation, and then densification is promoted by heat treatment. When using the sol-gel method, there are no particular restrictions on the method of applying the sol solution, and it can be appropriately selected according to the purpose. Examples include the dip method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, and gravure coating method. Examples of wet printing methods include letterpress, offset, gravure, intaglio, rubber plate, and screen printing. Furthermore, the temperature during the heat treatment after applying the sol solution is preferably 80°C or higher, and more preferably 100°C or higher.

[0056] There are no particular restrictions on the average thickness of the hole blocking layer, and it can be appropriately selected depending on the purpose, but it is preferably 5 nm to 1 μm, more preferably 500 nm to 700 nm for wet deposition, and more preferably 5 nm to 30 nm for dry deposition.

[0057] <<Electron transport layer>> The photoelectric conversion element has an electron transport layer having a photosensitizing compound. Preferably, the electron transport layer is disposed between the first electrode and the photosensitizing compound. The aforementioned electron transport layer is responsible for transporting electrons and also performs a hole-blocking function. The ionization potential of the photosensitized compound exceeds the ionization potential of the hole transport layer. When the ionization potential of the photosensitized compound exceeds the ionization potential of the hole transport layer, the efficiency of hole conduction to the hole transport layer is superior. The electron transport layer is formed for the purpose of transporting electrons generated by the photosensitizing compound to the first electrode or hole blocking layer. For this reason, it is preferable that the electron transport layer be positioned adjacent to the first electrode or hole blocking layer.

[0058] There are no particular restrictions on the structure of the electron transport layer, and it can be appropriately selected according to the purpose. However, in at least two adjacent photoelectric conversion elements, the electron transport layers may extend from each other, but it is preferable that they do not extend from each other. If electron transport layers are not extended from each other, electron diffusion is suppressed and leakage current decreases, which is advantageous in that it improves photodurability. Furthermore, the structure of the electron transport layer may be a single layer or a multilayer structure in which multiple layers are stacked.

[0059] The electron transport layer includes an electron transport material and, if necessary, other materials.

[0060] The electron transport material is not particularly limited and can be appropriately selected depending on the purpose, but semiconductor materials are preferred. The semiconductor material preferably has a particulate shape, and is formed into a porous film by bonding these parts together. A photosensitizing compound is chemically or physically adsorbed onto the surface of the semiconductor nanoparticles constituting the porous electron transport layer.

[0061] There are no particular limitations on the semiconductor material, and known materials can be used, such as elemental semiconductors, compound semiconductors, and compounds having a perovskite structure. Examples of the aforementioned single semiconductors include silicon and germanium. Examples of the aforementioned compound semiconductors include metal chalcogenides, specifically oxide semiconductors such as titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum; sulfide semiconductors such as cadmium, zinc, lead, silver, antimony, and bismuth; selenide semiconductors such as cadmium and lead; and telluride semiconductors such as cadmium. Other compound semiconductors include phosphide semiconductors such as zinc, gallium, indium, and cadmium; gallium arsenide; copper-indium-selenide semiconductors; and copper-indium-sulfide semiconductors. Examples of compounds having the perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate. Among these, oxide semiconductors are preferred, with titanium oxide, zinc oxide, tin oxide, and niobium oxide being particularly preferred. When the electron transport material of the electron transport layer is titanium oxide, it is advantageous in that a high conduction band level (conduction band) can be obtained, resulting in a high open-circuit voltage and high photoelectric conversion characteristics. Furthermore, it is advantageous in that a high refractive index allows for a high short-circuit current due to the photoconfinement effect. Moreover, it is advantageous in that a high dielectric constant and high mobility can be obtained, resulting in a high curve factor. These materials may be used individually or in combination of two or more. Furthermore, there are no particular restrictions on the crystal form of the semiconductor material; it can be appropriately selected according to the purpose, and may be single crystal, polycrystalline, or amorphous.

[0062] There are no particular restrictions on the average particle size of the primary particles of the semiconductor material, and it can be appropriately selected depending on the purpose, but it is preferably 1 nm to 100 nm, and more preferably 5 nm to 50 nm. Furthermore, semiconductor materials with a particle size larger than the number-average particle size may be mixed or layered, which may improve conversion efficiency due to the effect of scattering incident light. In this case, the number-average particle size is preferably 50 nm to 500 nm.

[0063] There are no particular restrictions on the average thickness of the electron transport layer, and it can be appropriately selected depending on the purpose, but it is preferably 50 nm to 100 μm, more preferably 100 nm to 50 μm, and even more preferably 120 nm to 10 μm. When the average thickness of the electron transport layer is within the preferred range, it is advantageous that a sufficient amount of photosensitizing compound per unit projected area can be secured, a high light capture rate can be maintained, the diffusion distance of injected electrons does not increase easily, and losses due to charge recombination can be reduced.

[0064] There are no particular limitations on the method for fabricating the electron transport layer, and it can be appropriately selected depending on the purpose. Examples include methods for forming a thin film in a vacuum, such as sputtering, wet film deposition methods, and wet printing methods. Among these, wet film deposition methods are preferred from the viewpoint of manufacturing cost, and a method of preparing a paste (a dispersion of semiconductor material) by dispersing the powder or sol of the semiconductor material and applying it to the first electrode as an electron current collector electrode substrate or to the hole blocking layer is more preferred. There are no particular limitations on the wet film formation method, and it can be appropriately selected depending on the purpose. Examples include the dip method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, and die coating method. As the aforementioned wet printing method, various methods such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing can be used.

[0065] One method for preparing the aforementioned dispersion of semiconductor material is, for example, a method of mechanically grinding the material using a known milling apparatus. By this method, a dispersion of semiconductor material can be prepared by dispersing particulate semiconductor material alone, or a mixture of semiconductor material and resin, in water or a solvent. Examples of the aforementioned resins include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, acrylic acid esters, and methacrylic acid esters, as well as silicone resins, phenoxy resins, polysulfone resins, polyvinyl butyral resins, polyvinyl formal resins, polyester resins, cellulose ester resins, cellulose ether resins, urethane resins, phenolic resins, epoxy resins, polycarbonate resins, polyarylate resins, polyamide resins, and polyimide resins. These may be used individually or in combination of two or more.

[0066] Examples of the aforementioned solvents include water, alcohol solvents, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents. Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, and α-terpineol. Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the ester solvent include ethyl formate, ethyl acetate, and n-butyl acetate. Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane. Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Examples of the halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene. Examples of the hydrocarbon solvents include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene. These can be used individually or in combination of two or more.

[0067] To prevent particle re-aggregation, an acid, surfactant, chelating agent, etc., may be added to the dispersion containing the semiconductor material or to the paste containing the semiconductor material obtained by the sol-gel method or the like. Examples of the aforementioned acids include hydrochloric acid, nitric acid, and acetic acid. Examples of the surfactant include polyoxyethylene octylphenyl ether. Examples of the chelating agent include acetylacetone, 2-aminoethanol, and ethylenediamine. Furthermore, adding a thickening agent is an effective method to improve film-forming properties. Examples of the thickening agents include polyethylene glycol, polyvinyl alcohol, and ethylcellulose.

[0068] After coating the semiconductor material, the particles of the semiconductor material can be brought into electronic contact, and the film can be fired, irradiated with microwaves or electron beams, or irradiated with laser light to improve film strength and adhesion to the substrate. These processes may be performed individually or in combination of two or more types.

[0069] When firing the electron transport layer formed from the semiconductor material, there are no particular restrictions on the firing temperature, and it can be appropriately selected according to the purpose. However, if the temperature is too high, the resistance of the substrate may increase or it may melt, so a temperature of 30°C to 700°C is preferred, and 100°C to 600°C is more preferred. Similarly, there are no particular restrictions on the firing time, and it can be appropriately selected according to the purpose, but a temperature of 10 minutes to 10 hours is preferred. When irradiating the electron transport layer formed from the semiconductor material with microwaves, there are no particular restrictions on the irradiation time, and it can be appropriately selected according to the purpose, but it is preferable to irradiate for 1 hour or less. In this case, the irradiation may be performed from the side on which the electron transport layer is formed, or from the side on which the electron transport layer is not formed.

[0070] After firing the electron transport layer made of the semiconductor material, chemical plating using an aqueous solution of titanium tetrachloride or a mixed solution with an organic solvent, or electrochemical plating using an aqueous solution of titanium trichloride may be performed, for example, in order to increase the surface area of ​​the electron transport layer and to improve the electron injection efficiency from the photosensitizing compound to the semiconductor material, as described later. A film obtained by sintering a semiconductor material with a diameter of several tens of nanometers can form a porous structure. Such a nanoporous structure has a very high surface area, which can be expressed using the roughness factor. The roughness factor is a numerical value that represents the actual area inside the porous structure relative to the area of ​​semiconductor particles coated on the first substrate. Therefore, a higher roughness factor is preferable, but a value of 20 or higher is preferable in relation to the average thickness of the electron transport layer. Furthermore, the electron-transporting material particles may be doped with lithium compounds. Specifically, this involves depositing a solution of lithium bis(trifluoromethanesulfonimide) compound onto the electron-transporting material particles using a spin coating or the like, followed by a calcination treatment. The lithium compound is not particularly limited and can be appropriately selected depending on the purpose. Examples include lithium bis(trifluoromethanesulfonimide), lithium bis(fluoromethanesulfonimide), lithium bis(fluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, lithium perchlorate, and lithium iodide.

[0071] A photosensitizing compound is provided between the electron transport layer and the hole transport layer.

[0072] <<Photosensitizing compound>> In this invention, in order to further improve the conversion efficiency, a photosensitizing compound is adsorbed onto the surface of the electron-transporting semiconductor of the electron transport layer. The aforementioned photosensitizing compound is a compound represented by the following general formula (1). By using a compound represented by the following general formula (1) as the photosensitizing compound, high output can be obtained in a photoelectric conversion element, particularly a solid-state dye-sensitized solar cell. [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka]

[0073] Furthermore, it is preferable that the compound represented by the general formula (1) is the compound represented by the following general formula (2). When the compound represented by the general formula (1) is the compound represented by the following general formula (2), the output can be improved in low-light to high-light environments. [ka] ...General formula (2) (In general formula (2), R2 represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka]

[0074] The following are specific example compounds represented by the general formulas (1) and (2), but the present invention is not limited to these. [ka] (B1-1) [ka] (B1-2) [ka] (B1-3) [ka] (B1-4) [ka] (B1-5) [ka] (B1-6) [ka] (B1-7) [ka] (B1-8) [ka] (B1-9)

[0075] As a method for adsorbing the photosensitizing compound onto the surface of the semiconductor material of the electron transport layer, methods such as immersing the electron transport layer containing the semiconductor material in a solution of the photosensitizing compound or a dispersion of the photosensitizing compound, or applying the solution of the photosensitizing compound or a dispersion of the photosensitizing compound to the electron transport layer and adsorbing it, can be used. In the case of immersing the electron transport layer on which the semiconductor material is formed in a solution of the photosensitizing compound or a dispersion of the photosensitizing compound, methods such as immersion, dipping, roller, and air knife can be used.

[0076] In the method of applying a solution or dispersion of the photosensitizing compound to the electron transport layer and adsorbing it, methods such as the wire bar method, slide hopper method, extrusion method, curtain method, spin method, and spray method can be used. It is also possible to adsorb the compound in a supercritical fluid such as carbon dioxide.

[0077] When adsorbing the photosensitizing compound onto the semiconductor material, a condensing agent may be used in combination. The condensing agent may be one that acts catalytically, physically or chemically, to bond the photosensitizing compound to the surface of the semiconductor material, or one that acts stoichiometrically, shifting the chemical equilibrium favorably. Furthermore, thiols, hydroxy compounds, and the like may be added as condensation aids.

[0078] Examples of solvents for dissolving or dispersing the photosensitizing compound include water, alcohol solvents, ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents. Examples of the alcohol solvent include methanol, ethanol, and isopropyl alcohol. Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the ester solvent include ethyl formate, ethyl acetate, and n-butyl acetate. Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane. Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Examples of the halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene. Examples of the hydrocarbon solvents include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene. These can be used individually or in combination of two or more.

[0079] Since some of the aforementioned photosensitizing compounds work more effectively when aggregation between compounds is suppressed, a coagulation dissociation agent may be used in combination. Examples of the aforementioned flocculation dissociation agents include steroid compounds such as cholic acid and chenodeoxycholic acid, long-chain alkyl carboxylic acids, or long-chain alkylphosphonic acids. Compounds represented by the following general formula (3) are particularly preferred, and 4-benzyloxybenzoic acid (compound B2-1 below) is more preferred. [ka] ...General formula (3) (In general formula (3), n represents a natural number from 1 to 3, and Ar3 represents an optionally substituted phenyl group or naphthyl group.) The following are specific example compounds of the flocculation-dissociating agent represented by general formula (3), but the present invention is not limited to these.

[0080] [ka] (B2-1) [ka] (B2-2) [ka] (B2-3) [ka] (B2-4) [ka] (B2-5) [ka] (B2-6) [ka] (B2-7) [ka] (B2-8) [ka] (B2-9) [ka] (B2-10) [ka] (B2-11) [ka] (B2-13) [ka] (B2-14)

[0081] The content of the agglomerating dissociant is preferably 0.5 moles to 100 moles, and more preferably 10 moles to 50 moles, per mole of the photosensitizing compound.

[0082] The temperature at which the photosensitizing compound, or the photosensitizing compound and the agglomerating dissociator, are adsorbed onto the surface of the semiconductor material constituting the electron transport layer is preferably between -50°C and 200°C. The adsorption time is preferably 5 seconds to 1,000 hours, more preferably 10 seconds to 500 hours, and even more preferably 1 minute to 150 hours. The adsorption process is preferably carried out in a dark place. Furthermore, the adsorption process may be carried out while standing still or while stirring. There are no particular restrictions on the method of stirring, and it can be appropriately selected depending on the purpose. Examples include methods using a stirrer, ball mill, paint conditioner, sand mill, attritor, disperser, ultrasonic dispersion, etc.

[0083] <<Hall transport layer>> The aforementioned hole transport layer is a layer that functions to transport holes (positive voids). The hole transport layer can be made of any known material that has the function of transporting holes. Examples include an electrolyte in which a redox pair is dissolved in an organic solvent, a gel electrolyte in which a liquid in which a redox pair is dissolved in an organic solvent is impregnated into a polymer matrix, a molten salt containing a redox pair, a solid electrolyte, an inorganic hole transport material, and an organic hole transport material. Among these, electrolytes and gel electrolytes can be used, but solid electrolytes are preferred, and organic hole transport materials are more preferred.

[0084] The hole transport layer preferably contains a p-type semiconductor material, an alkali metal salt, and a basic compound.

[0085] -p-type semiconductor materials- The hole transport layer contains a p-type semiconductor material in order to obtain the function of transporting holes. The ionization potential of the hole transport layer exceeds the ionization potential of the p-type semiconductor material and is less than 1.07 times the ionization potential of the p-type semiconductor material. When the ionization potential of the hole transport layer exceeds the ionization potential of the p-type semiconductor material and is less than 1.07 times the ionization potential of the p-type semiconductor material, it is possible to achieve both high photoelectric conversion performance and long-term stability even in low-intensity light. There are no particular restrictions on the p-type semiconductor material, and it can be appropriately selected according to the purpose. Examples include inorganic p-type semiconductor materials and organic p-type semiconductor materials. The inorganic p-type semiconductor material is not particularly limited and can be appropriately selected depending on the purpose. Examples include CuSCN, CuI, CuBr, NiO, V2O5, and graphene oxide. Among these, organic p-type semiconductor materials are preferred.

[0086] The above-mentioned organic p-type semiconductor material and the like are not particularly limited and can be appropriately selected according to the purpose. For example, known organic p-type semiconductor materials can be used. Examples of the known organic p-type semiconductor materials include oxadiazole compounds, triphenylmethane compounds, pyrazoline compounds, hydrazone compounds, oxadiazole compounds, tetraarylbenzidine compounds, stilbene compounds, spiro-type compounds, and the like. These may be used alone or in combination of two or more. Among these, spiro-type compounds are preferred.

[0087] As the spiro-type compound, a compound containing the following general formula (20) is preferred.

[0088]

Chemical formula

[0089]

Chemical formula

[0090]

Chemical formula

[0091]

Chemical formula

[0092]

Chemical formula

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] Furthermore, as a spiro-type compound used as a hole transport material, compounds represented by the following general formula (4) can be particularly preferred. [ka] However, in the general formula (4) above, R3 represents a hydrogen atom or an alkyl group.

[0097] For example, of the above (D-1) to (D-20), those that can be represented by the above general formula (4) are (D-7) and (D-10).

[0098] These spiro-type compounds exhibit high hole mobility, and because two benzidine skeleton molecules are twisted and bonded together, they form a near-spherical electron cloud, resulting in good intermolecular hopping conductivity and excellent photoelectric conversion properties. Furthermore, they are highly soluble in various organic solvents and, being amorphous (amorphous material without a crystalline structure), readily pack into porous electron transport layers. Moreover, because they do not possess light absorption characteristics above 450 nm, they allow for efficient light absorption by photosensitizing compounds, making them particularly favorable for solid-state dye-sensitized solar cells.

[0099] - Alkali metal salts - If the hole transport layer contains an alkali metal salt, the output can be improved, and furthermore, the resistance to light irradiation and high-temperature storage can be improved. Specific examples of the alkali metal salt include those shown in the following (C-1) to (C-86), those represented by the following general formula (5), etc., but are not limited thereto.

[0100]

Chem.

[0101]

Chem.

[0102]

Chem.

[0103]

Chem.

[0104]

Chem.

[0105]

Chem.

[0106]

Chem.

[0107]

Chem.

[0108]

Chem.

[0109]

Chem.

[0110] Examples of lithium salts represented by the general formula (5) include lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (Li-FTFSI), lithium (fluorosulfonyl)(pentafluoroethanesulfonyl)imide (Li-FPFSI), lithium (fluorosulfonyl)(nonafluorobutanesulfonyl)imide (Li-FNFSI), lithium (nonafluorobutanesulfonyl)(trifluoromethanesulfonyl)imide (Li-NFTFSI), and lithium (pentafluoroethanesulfonyl)(trifluoromethanesulfonyl)imide (Li-PFTFSI). Among these, lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) and lithium (fluorosulfonyl)(trifluoromethylsulfonyl)imide (Li-FTFSI) are particularly preferred.

[0111] The structural formulas of specific lithium salts represented by the general formula (5) are as follows.

[0112] [ka]

[0113] The lithium salt represented by the general formula (5) is involved in charge transfer, and good photoelectric conversion characteristics can be obtained by including this lithium salt.

[0114] Here, for example, when coating is performed using a coating solution for forming a hole transport layer that contains the lithium salt represented by the general formula (5), the lithium salt does not need to be contained in the formed film in the form of a salt in which anion and cation are bonded, but may be contained in a state in which lithium cation and anion are separated. Specifically, the inventors have found that when a hole transport layer is formed with the lithium salt represented by the general formula (5) contained in a coating solution for forming a hole transport layer, the lithium cations migrate to the electron transport layer and are contained in greater quantities in the electron transport layer than in the hole transport layer. On the other hand, the inventors have found that, although some anions migrate to the electron transport layer, they are contained in greater quantities in the hole transport layer than in the electron transport layer. In the present invention, it is preferable that the cations and anions of the lithium salt represented by the general formula (5) are separated and each forms a different distribution state, and by including these in the photoelectric conversion layer, it is possible to further improve the effect of obtaining high output for low-intensity light even in low-temperature environments and having excellent output sustainability.

[0115] The form of the hole transport layer is not particularly limited as long as it has the function of transporting holes, and can be appropriately selected according to the purpose. Examples include an electrolyte in which a redox pair is dissolved in an organic solvent, a gel electrolyte in which a liquid in which a redox pair is dissolved in an organic solvent is impregnated into a polymer matrix, a molten salt containing a redox pair, a solid electrolyte, an inorganic hole transport material, and an organic hole transport material. Among these, a solid electrolyte is preferred, and an organic hole transport material is more preferred. These may be used individually or in combination of two or more.

[0116] In addition to the lithium salts mentioned above, the hole transport layer in the photoelectric conversion layer may also contain other lithium salts. These lithium salts may have symmetric anion species, such as lithium bis(fluorosulfonyl)imide (Li-FSI), lithium bis(pentafluoroethanesulfonyl)imide (Li-BETI), and lithium bis(nonafluorobutanesulfonyl)imide. Cyclic imides such as lithium (cyclohexafluoropropane)(disulfone)imide are also possible. However, these lithium salts have low compatibility because their anions are symmetrical, making it difficult to increase the amount added. Therefore, if they are added at all, a small amount is preferable.

[0117] The lithium salt content represented by the general formula (5) above is preferably 5 mol% to 50 mol%, and more preferably 20 mol% to 35 mol%, relative to the hole transport material. By having the content within this range, high output for low-intensity light is achieved, the output retention rate is improved, and high durability is achieved simultaneously.

[0118] The cation of the lithium salt represented by the general formula (5) is thought to be present at the interface near the electron transport layer, and the anion of the lithium salt represented by the general formula (5) is thought to be doped into the hole transport layer.

[0119] The alkali metal salt content is preferably 30 mol% to 80 mol%, and more preferably 50 mol% to 70 mol%, relative to the total amount of the hole transport material.

[0120] Furthermore, the lithium cations in the lithium salt represented by the general formula (5) above may be migrated to the electron transport layer, for example, more than half of the lithium cations may be contained in the electron transport layer described later. Furthermore, the hole transport layer in this invention is more preferable because its output can be further improved by filling it inside the electron transport layer, which will be described later. In this case, the hole transport layer filled inside the electron transport layer is also treated as a hole transport layer.

[0121] -Basic compounds- The aforementioned basic compound is thought to be present at the interface near the electron transport layer and is believed to suppress reverse electron transfer from the electron transport layer (i.e., electron transfer from the electron transport layer to the hole transport layer).

[0122] The basic compound is preferably a basic compound (pyridine compound) consisting of the following general formula (A) or general formula (B), and more preferably a tertiary amine compound represented by the following general formulas (A1) and (B1). Including a basic compound of the following general formulas (A) or (B) in the hole transport layer is advantageous in that a high open-circuit voltage can be obtained and high photoelectric conversion characteristics can be obtained. Furthermore, by having at least one of the tertiary amine compounds represented by general formulas (A1) and (B1) in the hole transport layer, it is possible to achieve both high photoelectric conversion performance and long-term stability even in low-intensity light.

[0123] [ka] (In the formula, R1 and R2 each independently represent an alkyl group or an aromatic hydrocarbon group, and may represent the same or different groups, or R1 and R2 may be bonded to each other and represent a heterocyclic group containing a nitrogen atom.)

[0124] [ka] (In the formula, R1 and R2 each independently represent an alkyl group or an aromatic hydrocarbon group, and may represent the same or different groups, or R1 and R2 may be bonded to each other and represent a heterocyclic group containing a nitrogen atom.)

[0125] [ka]

[0126] [ka] However, in the above general formula (A1) and the above general formula (B1), Ar1 and Ar2 represent aryl groups which may have substituents, and Ar1 and Ar2 may be the same or different, and may be bonded to each other.

[0127] The following are specific examples of basic compounds of general formula (A) and general formula (B), but the present invention is not limited to these.

[0128] [ka]

[0129] [ka]

[0130] Next, specific examples of tertiary amine compounds represented by the above general formulas (A1) and (B1) include, but are not limited to, the exemplary compounds C-1 to C-20 shown below. These may be used individually or in combination of two or more.

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] [ka]

[0135] [ka]

[0136] [ka]

[0137] Examples of aryl groups in Ar1 and Ar2 include phenyl, naphthyl, and biphenyl groups. Examples of substituents include alkyl and alkoxy groups.

[0138] The hole transport layer preferably contains a basic compound represented by the general formula (A1) above. Including a basic compound represented by the general formula (A1) in the hole transport layer is advantageous in that it enhances the output stability of the photoelectric conversion element. In particular, it is advantageous in that it reduces variations in output characteristics for low-intensity light and enables stable power generation.

[0139] The following are specific examples of basic compounds represented by the general formula (A1) above, but the present invention is not limited to these.

[0140] [ka]

[0141] In addition to the basic compounds mentioned above, basic compounds such as 4-dimethylaminopyridine (DMAP), 4-pyrrolidinopyridine (PYP), 4-piperidinopyridine (PPP), and tert-butylpyridine (TBP) are also preferred.

[0142] The content of the basic compound in the hole transport layer is preferably 20 mol% to 65 mol%, and more preferably 35 mol% to 50 mol%, relative to the hole transport material. This preferred range for the basic compound content allows for the maintenance of a high open-circuit voltage, high output, and high stability and durability even with long-term use in various environments.

[0143] -Oxidizing agent- The hole transport layer preferably contains an oxidizing agent. By containing the oxidizing agent in the hole transport layer, some of the organic hole transport material becomes radical cations, thereby improving conductivity and enhancing the durability and stability of the output characteristics. The oxidizing agent causes the organic hole transport material to oxidize, resulting in good hole conductivity and good long-term stability by suppressing the release (reduction) of the oxidation state due to the surrounding environment of the photoelectric conversion layer.

[0144] The oxidizing agent is not particularly limited and can be appropriately selected depending on the purpose. Examples include tris(4-bromophenyl)aminium hexachloroantimonate, silver hexafluoroantimonate, nitrosonium tetrafluorolate, silver nitrate, metal complexes, and hypervalent iodine compounds. These may be used individually or in combination of two or more. Among these, metal complexes and hypervalent iodine compounds are preferred. When the oxidizing agent is a metal complex or a hypervalent iodine compound, it is advantageous that it can be added in large quantities due to its high solubility in organic solvents.

[0145] --Metallic Compounds-- The aforementioned metal complex is composed of, for example, a metal cation, a ligand, and an anion.

[0146] The metal cation is not particularly limited and can be appropriately selected according to the purpose. For example, cations such as chromium, manganese, zinc, iron, cobalt, nickel, copper, molybdenum, ruthenium, rhodium, palladium, silver, tungsten, rhenium, osmium, iridium, vanadium, gold, platinum, etc. can be mentioned. Among these, cations of manganese, zinc, iron, cobalt, nickel, copper, ruthenium, silver, and vanadium are preferred, and cobalt complexes are more preferred.

[0147] As the ligand, those containing at least one 5- or 6-membered heterocyclic ring containing nitrogen are preferred, and may have substituents. Specific examples include, but are not limited to, the following.

[0148]

Chemical formula

[0149]

Chemical formula

[0150]

Chemical formula

[0151] Examples of the anion include, for example, hydride ion (H - ), fluoride ion (F - ), chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ), hydroxide ion (OH - ), cyanide ion (CN - ), nitrate ion (NO3 - ), nitrite ion (NO2 - ), hypochlorite ion (ClO - ), chlorite ion (ClO2 - ), chlorate ion (ClO3 -), perchlorate ion (ClO4 - ), permanganate ion (MnO4 - ), acetate ion (CH3COO - ), bicarbonate ions (HCO3) - ), dihydrogen phosphate (H2PO4) - ), hydrogen sulfate ion (HSO4) - ), hydrogen sulfide ions (HS - ), thiocyanate ion (SCN - ), tetrafluoroborate ion (BF4 - ), hexafluorophosphate ion (PF6 - ), tetracyanoborate ion (B(CN)4 - ), dicyanoamine ion (N(CN)2 - ), p-toluenesulfonate ion (TsO - ), trifluoromethylsulfonate ion (CF3SO2-), bis(trifluoromethylsulfonyl)amine ion (N(SO2CF3)2 - ), tetrahydroxoaluminate ion ([Al(OH)4] - , or [Al(OH)4(H2O)2] - ), dicyanosilver(I) ion ([Ag(CN)2] - ), tetrahydroxochrome(III) ion ([Cr(OH)4] - ), tetrachloroaurate(III) ion ([AuCl4] - ), oxide ions (O2-), sulfide ions (S 2- ), peroxide ions (O2 2- ), sulfate ions (SO4 2- ), sulfite ions (SO3 2- ), thiosulfate ion (S2O3 2- ), carbonate ions (CO3 2- ), chromate ion (CrO4 2- ), dichromate ion (Cr2O7 2- ), monohydrogen phosphate (HPO4) 2- ), tetrahydroxozinc(II) ion ([Z n (OH)4] 2- ), tetracyanozinc(II) ion ([Zn(CN)4] 2-), tetrachlorocopper(II) ion ([CuCl4] 2- ), phosphate ion (PO4 3- ), hexacyanoferrate(III) ion ([Fe(CN)6] 3- ), bis(thiosulfato)silver(I) ion ([Ag(S2O3)2] 3- ), hexacyanoferrate(II) ion ([Fe(CN)6] 4- Examples include the following. Among these, tetrafluoroborate ions, hexafluorophosphate ions, tetracyanoborate ions, bis(trifluoromethylsulfonyl)amine ions, and perchlorate ions are preferred.

[0152] As the aforementioned metal complex, it is particularly preferable to add a trivalent cobalt complex. Adding a trivalent cobalt complex as an oxidizing agent makes it possible to oxidize and stabilize the hole transport material, thereby improving hole transportability. In the present invention, for example, it is preferable to use a trivalent cobalt complex added to the coating solution for forming the hole transport layer, but it is preferable that the hole transport layer of the photoelectric conversion element obtained using the coating solution for forming the hole transport layer contains a divalent cobalt complex. This is because when the trivalent cobalt complex is mixed with the hole transport material, the hole transport material is oxidized and the cobalt complex becomes divalent. In other words, in the present invention, it is preferable that the photoelectric conversion layer further contains a divalent cobalt complex. In particular, it is especially preferable that almost no trivalent cobalt complexes remain in the hole transport layer of the photoelectric conversion element, and that almost all cobalt complexes are divalent. This improves and stabilizes hole transport, enabling higher power output and greater sustainability, as well as allowing the effects to be further demonstrated even in low-temperature environments.

[0153] The valency of the cobalt complex contained in the hole transport layer can be clarified, for example, by performing XAFS analysis. XAFS stands for X-ray Absorption Fine Structure, and is also called X-ray absorption fine structure analysis. For example, an XAFS spectrum can be obtained by irradiating a sample with X-rays and measuring the amount of absorption. In XAFS spectra, the structure near the absorption edge is called XANES (X-ray Absorption Near Edge Structure), and the broad-spectrum X-ray absorption fine structure that appears at energies approximately 100 eV or more above the absorption edge is called EXAFS (Extended X-ray Absorption Fine Structure). However, information regarding the valence and structure of the atom of interest can be mainly obtained from the former, XANES. In this case, for example, by separately measuring the XAFS spectra of divalent and trivalent cobalt complex powders and comparing them with the XAFS spectra of the cobalt complex contained in the hole transport layer, the valence of the cobalt complex contained in the hole transport layer can be determined. Figure 18 shows the results of acquiring the XAFS spectrum for the photoelectric conversion element of the present invention (Example 1) as described above. As shown in Figure 18, the cobalt complex contained in the hole transport layer of an example of the photoelectric conversion element of the present invention closely matches the divalent cobalt complex powder, and there is no portion that matches the trivalent cobalt complex powder, so it can be concluded that almost all of the contained cobalt complex is divalent.

[0154] The trivalent cobalt complex added to the coating solution for forming the hole transport layer is preferably the cobalt complex represented by the following structural formulas (4) and (5).

[0155] [ka]

[0156] [ka] However, in the above structural formulas (4) and (5), R8 to R10 X represents a hydrogen atom, a methyl group, an ethyl group, a tert-butyl group, or a trifluoromethyl group. X represents one of the following structural formulas (6) to (9).

[0157] [ka]

[0158] Regarding X, structural formula (8) is more preferred among the structural formulas (6) to (9) mentioned above. Using structural formula (8) is effective in that the hole transport material can be stably maintained in an oxidized state.

[0159] Specific examples of these cobalt complexes include (F-1) to (F-24) shown below. However, they are not limited to these examples.

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] Among these, (F-18) and (F-23) are preferred.

[0164] --Hypervalent iodine compounds-- The aforementioned hypervalent iodine compound refers to a compound containing iodine atoms that have nine or more formal valence electrons, exceeding the octet rule. In other words, a hypervalent iodine compound refers to a compound containing iodine atoms that have more electrons than the eight required by the octet rule and are in a hypervalent state. Here, valence electrons, also called atomic valence electrons, refer to electrons that occupy the outer electron shells in the electron configuration of an atom, excluding the inner shell electrons. The photoelectric conversion element can improve the durability and stability of its output by including a hypervalent iodine compound in its hole transport layer.

[0165] There are no particular limitations on the hypervalent iodine compounds that can be used in the present invention, and they can be appropriately selected depending on the purpose, but it is preferable that they contain at least one of a periodinane compound and a diaryliodonium salt. Periodinane compounds and diaryliodonium salts have high solubility in halogenated solvents such as chlorobenzene, and exhibit low crystallinity and acidity. Therefore, by including at least one of the periodinane compounds and diaryliodonium salts in the hole transport layer, the output of the photoelectric conversion element can be improved. In photoelectric conversion elements, the open-circuit voltage can be improved by lowering the acidity of the hole transport layer; therefore, materials with low acidity are preferred for the hole transport layer. One method to lower the acidity of the hole transport layer is to increase the proportion (content) of basic materials in the hole transport layer. However, in this case, the proportion of hole-transporting compounds in the hole transport layer decreases. Consequently, improving the open-circuit voltage by increasing the proportion of basic materials in the hole transport layer increases the series resistance, leading to a decrease in output at high light intensity. For the reasons stated above, when reducing the acidity of the hole transport layer, it is preferable to use materials that have high solubility in halogenated solvents such as chlorobenzene, such as periodinane compounds and diaryliodonium salts, and that have low crystallinity and acidity.

[0166] Among the hypervalent iodine compounds, periodinane compounds represented by the following general formula (8) and diaryliodonium salts represented by the following general formula (9) were found to produce high output when used as oxidizing agents in the hole transport layer due to their high solubility, low crystallinity, and low acidity. High acidity in the hole transport layer results in a low open-circuit voltage. It is possible to increase the open-circuit voltage by increasing the amount of basic material added, but this reduces the concentration of the hole transport material, which increases the series resistance and decreases the output at high light intensity. [ka] ...General formula (8) (In the formula, R1 to R5 represent hydrogen atoms or methyl groups. R6 and R7 represent methyl groups or trifluoromethyl groups.) [ka] ...General formula (9) (In the formula, X represents one of the following structural formulas.) BF4...Structural formula (1) PF6...Structural formula (2) [ka] ...Structural formula (3) [ka] ...Structural formula (4)

[0167] Specific examples of the periodinane compound represented by the general formula (8) and the diaryliodonium salt represented by the general formula (9) include, for example, (G-1) to (G-10) shown below. However, it is not limited to these.

[0168] [ka]

[0169] [ka]

[0170] Other hypervalent iodine compounds with the following structural formulas are also acceptable.

[0171] [ka]

[0172] Furthermore, the product may also contain a compound represented by the following general formula (10) as an oxidizing agent.

[0173] [ka] ...General formula (10) (In general formula (10), R1 to R5 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group, and may be the same or different. X represents a cation.)

[0174] Specific examples of compounds represented by general formula (10) include (I-1) to (I-28) below, but are not limited to these.

[0175] [ka]

[0176] [ka]

[0177] [ka]

[0178] [ka]

[0179] [ka]

[0180] [ka]

[0181] The content of the oxidizing agent is preferably 0.5 parts by mass or more and 50 parts by mass or less, and more preferably 5 parts by mass or more and 30 parts by mass or less, per 100 parts by mass of the hole transport material. It is not necessary for all of the hole transport material to be oxidized by the addition of the oxidizing agent; it is effective if only a portion is oxidized.

[0182] The hole transport layer may be a single-layer structure made of a single material, or a multilayer structure containing multiple compounds. When the hole transport layer is a multilayer structure, it is preferable to use a polymer material in the hole transport layer closest to the second electrode, which will be described later. Using a polymer material with excellent film-forming properties is advantageous because it can further smooth the surface of the porous electron transport layer, thereby improving the photoelectric conversion characteristics. Furthermore, since the polymer material does not easily penetrate into the interior of the porous electron transport layer, it has excellent coverage of the surface of the porous electron transport layer, and may also be effective in preventing short circuits when setting up electrodes.

[0183] There are no particular limitations on the polymer material used in the hole transport layer, and examples include known hole-transporting polymer materials. Examples of the hole-transporting polymer materials include polythiophene compounds, polyphenylene vinylene compounds, polyfluorene compounds, polyphenylene compounds, polyarylamine compounds, and polythiodiazole compounds. Examples of the polythiophene compounds include poly(3-n-hexylthiophene), poly(3-n-octyloxythiophene), poly(9,9'-dioctylfluorenco-bithiophene), poly(3,3'''-didodecyl-quarterthiophene), poly(3,6-dioctylthieno[3,2-b]thiophene), and poly(2,5-bis(3-decylthiophen-2-yl)thieno[3 Examples include poly(3,4-didecylthiophene-co-thieno[3,2-b]thiophene), poly(3,6-dioctylthiophene[3,2-b]thiophene-co-thieno[3,2-b]thiophene), poly(3,6-dioctylthiophene[3,2-b]thiophene-co-thiophene), and poly(3,6-dioctylthiophene[3,2-b]thiophene-co-bithiophene). Examples of the polyphenylene vinylene compounds include poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylene vinylene], and poly[(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene)-co-(4,4'-biphenylene vinylene)]. Examples of the aforementioned polyfluorene compounds include poly(9,9'-didodecylfluorenyl-2,7-diyl), poly[(9,9-dioctyl-2,7-divinylenefluorene)-alt-co-(9,10-anthracene)], poly[(9,9-dioctyl-2,7-divinylenefluorene)-alt-co-(4,4'-biphenylene)], poly[(9,9-dioctyl-2,7-divinylenefluorene)-alt-co-(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene)], and poly[(9,9-dioctyl-2,7-diyl)-co-(1,4-(2,5-dihexyloxy)benzene)]. Examples of the aforementioned polyphenylene compounds include poly[2,5-dioctyloxy-1,4-phenylene] and poly[2,5-di(2-ethylhexyloxy-1,4-phenylene]. Examples of the aforementioned polyarylamine compounds include poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(N,N'-diphenyl)-N,N'-di(p-hexylphenyl)-1,4-diaminobenzene], poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(N,N'-bis(4-octyloxyphenyl)benzidine-N,N'-(1,4-diphenylene)], poly[(N,N'-bis(4-octyloxyphenyl)benzidine-N,N'-(1,4-diphenylene)], Examples include poly[(N,N'-bis(4-(2-ethylhexyloxy)phenyl)benzidine-N,N'-(1,4-diphenylene)], poly[phenylimino-1,4-phenylenevinylene-2,5-dioctyloxy-1,4-phenylenevinylene-1,4-phenylene], poly[p-tolylumino-1,4-phenylenevinylene-2,5-di(2-ethylhexyloxy)-1,4-phenylenevinylene-1,4-phenylene], and poly[4-(2-ethylhexyloxy)phenylimino-1,4-biphenylene]. Examples of the aforementioned polythiadiazole compounds include poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo(2,1',3)thiadiazole)] and poly(3,4-didecylthiophene-co-(1,4-benzo(2,1',3)thiadiazole). Among these, polythiophene compounds and polyarylamine compounds are preferred from the viewpoint of carrier mobility and ionization potential.

[0184] Various additives may be added to the materials used for transporting the hall. Examples of additives include metal iodides such as iodine, lithium iodide, sodium iodide, potassium iodide, cesium iodide, calcium iodide, copper iodide, iron iodide, and silver iodide; quaternary ammonium salts such as tetraalkylammonium iodide and pyridinium iodide; metal bromides such as lithium bromide, sodium bromide, potassium bromide, cesium bromide, and calcium bromide; brominated salts of quaternary ammonium compounds such as tetraalkylammonium bromide and pyridinium bromide; metal chlorides such as copper chloride and silver chloride; metal acetates such as copper acetate, silver acetate, and palladium acetate; metal sulfates such as copper sulfate and zinc sulfate; metal complexes such as ferrocyanate-ferricyanate and ferrocene-ferricinium ions; sodium polysulfide; alkyl Examples include sulfur compounds such as thiol-alkyl disulfides, viologen dyes, hydroquinones, imidazolium compounds of ionic liquids described in Inorg. Chem. 35 (1996) 1168, such as 1,2-dimethyl-3-n-propylimidazoinium iodide, 1-methyl-3-n-hexylimidazolinium iodide, 1,2-dimethyl-3-ethylimidazolium trifluoromethanesulfonate, 1-methyl-3-butylimidazolium nonafluorobutylsulfonate, and 1-methyl-3-ethylimidazolium bis(trifluoromethyl)sulfonylimide, as well as basic compounds such as pyridine, 4-t-butylpyridine, benzimidazole, or derivatives thereof, and alkali metal salts.

[0185] There are no particular restrictions on the average thickness of the hole transport layer, and it can be appropriately selected depending on the purpose. However, it is preferable that it has a structure that penetrates into the pores of the porous electron transport layer, and is preferably 0.01 μm to 20 μm on the electron transport layer, more preferably 0.1 μm to 10 μm, and even more preferably 0.2 μm to 2 μm.

[0186] The hole transport layer can be formed directly on the electron transport layer on which the photosensitizing compound is adsorbed. There are no particular limitations on the method for producing the hole transport layer, and it can be appropriately selected depending on the purpose. Examples include methods for forming a thin film in a vacuum, such as vacuum deposition, and wet film formation methods. Among these, wet film formation methods are particularly preferred in terms of manufacturing cost, and a method of coating the electron transport layer is preferred. When using the wet film formation method described above, there are no particular restrictions on the coating method, and it can be carried out according to known methods, such as the dip method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, die coating method, and various other methods can be used as wet printing methods, such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing.

[0187] Furthermore, the film may be formed in a supercritical fluid or a subcritical fluid at a temperature and pressure lower than the critical point. The supercritical fluid is not particularly limited as long as it exists as a non-cohesive, high-density fluid in a temperature and pressure range beyond the limit (critical point) where gas and liquid can coexist, does not cohesive even when compressed, and is at or above the critical temperature and critical pressure. It can be appropriately selected according to the purpose, but one with a low critical temperature is preferred.

[0188] Examples of the supercritical fluid include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, alcohol solvents, hydrocarbon solvents, halogen solvents, and ether solvents. Examples of the alcohol solvent include methanol, ethanol, and n-butanol. Examples of the hydrocarbon solvents include ethane, propane, 2,3-dimethylbutane, benzene, and toluene. Examples of the halogen solvent include methylene chloride and chlorotrifluoromethane. Examples of the ether solvent include dimethyl ether. These can be used individually or in combination of two or more. Among these, carbon dioxide is preferred because it can easily create a supercritical state due to its critical pressure of 7.3 MPa and critical temperature of 31°C, and is also non-flammable and easy to handle.

[0189] The subcritical fluid is not particularly limited as long as it exists as a high-pressure liquid in the temperature and pressure range near the critical point, and can be appropriately selected according to the purpose. Compounds listed as supercritical fluids can also be suitably used as subcritical fluids.

[0190] The critical temperature and critical pressure of the supercritical fluid are not particularly limited and can be appropriately selected depending on the purpose, but the critical temperature is preferably between -273°C and 300°C, and more preferably between 0°C and 200°C.

[0191] Furthermore, in addition to the supercritical fluid and subcritical fluid, organic solvents and entrainers can also be used in combination. The addition of organic solvents and entrainers makes it easier to adjust the solubility in the supercritical fluid. The aforementioned organic solvent is not particularly limited as long as it contains chlorobenzene, and can be appropriately selected depending on the purpose. Examples include ketone solvents, ester solvents, ether solvents, amide solvents, halogenated hydrocarbon solvents, and hydrocarbon solvents. Examples of the ketone solvent include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the ester solvent include ethyl formate, ethyl acetate, and n-butyl acetate. Examples of the ether solvent include diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane. Examples of the amide solvent include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Examples of the halogenated hydrocarbon solvents include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene. Examples of the hydrocarbon solvents include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene. These can be used individually or in combination of two or more.

[0192] Furthermore, as a method for producing the hole transport layer, it is preferable to apply the hole transport layer forming material containing the material for forming the hole transport layer onto the electron transport layer on which the photosensitizing compound is adsorbed, and then dry it before forming the second electrode, and heat drying is preferable. There are no particular restrictions on the pressure used in the aforementioned heating and drying conditions, but it is preferable to carry it out under atmospheric pressure. The temperature in the aforementioned heating and drying conditions is preferably 30°C to 130°C, and more preferably 50°C to 100°C. The processing time under the aforementioned heating and drying conditions is preferably 10 minutes to 24 hours, and more preferably 30 minutes to 2 hours. The method for performing the aforementioned heating and drying is not particularly limited as long as the above-described heating and drying conditions can be achieved, and can be appropriately selected according to the purpose. For example, the following methods can be used: any conventionally known method that can heat the material, such as an oven, dryer, constant temperature bath, or hot plate, can be used.

[0193] Alternatively, a hole transport material may be laminated onto an electron transport layer on which a photosensitizing compound has been adsorbed, and then subjected to a pressing process. By applying the pressing process, the hole transport material adheres more closely to the electron transport layer, which is a porous electrode, so efficiency may be improved. There are no particular restrictions on the pressing method, and it can be appropriately selected according to the purpose. Examples include press molding methods using flat plates, such as those used in IR tablet molders, and roll press methods using rollers, etc. The aforementioned pressure is 10 kgf / cm². 2 The above is preferable, and 30 kgf / cm² 2 The above is preferable. There are no particular restrictions on the pressing time, and it can be appropriately selected depending on the purpose, but it is preferable to use a time of one hour or less. Heat may also be applied during the pressing process. A release agent may be placed between the press and the electrode during the pressing process.

[0194] Examples of the mold release agent include fluororesins such as polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene hexafluoropropylene copolymer, perfluoroalkoxy fluororesin, polyvinylidene fluoride, ethylene tetrafluoroethylene copolymer, ethylene chlorotrifluoroethylene copolymer, and polyvinyl fluoride. These may be used individually or in combination of two or more.

[0195] After the pressing process described above, and before providing the second electrode, a metal oxide may be provided between the hole transport material and the second electrode. Examples of the aforementioned metal oxides include molybdenum oxide, tungsten oxide, vanadium oxide, and nickel oxide. These may be used individually or in combination of two or more. Among these, molybdenum oxide is preferred. There are no particular limitations on the method for providing the metal oxide on the hole transport layer, and it can be appropriately selected depending on the purpose. Examples include methods for forming thin films in a vacuum, such as sputtering and vacuum deposition, and wet film formation methods.

[0196] As the wet film formation method, a method is preferred in which a paste is prepared by dispersing metal oxide powder or sol and applied to the hole transport layer. There are no particular restrictions on the application method when using the wet film formation method, and it can be carried out according to known methods, such as the dip method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, die coating method, and as a wet printing method, various methods such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing can be used. The average thickness of the coated metal oxide is preferably 0.1 nm to 50 nm, and more preferably 1 nm to 10 nm.

[0197] <Second electrode> The second electrode can be formed on the hole transport layer or on the metal oxide in the hole transport layer. Furthermore, the second electrode can be the same as the first electrode, and a second substrate is not necessarily required if sufficient strength is maintained.

[0198] Examples of materials for the second electrode include metals, carbon compounds, conductive metal oxides, and conductive polymers. Examples of the aforementioned metals include platinum, gold, silver, copper, and aluminum. Examples of the carbon compounds mentioned above include graphite, fullerene, carbon nanotubes, and graphene. Examples of the conductive metal oxides include ITO, FTO, and ATO. Examples of the conductive polymer include polythiophene and polyaniline. Examples of translucent structures include silver nanowires alone or a mixture with carbon nanotubes. These can be used individually or in combination of two or more.

[0199] The second electrode can be formed on the hole transport layer using methods such as coating, lamination, vapor deposition, CVD, or bonding, depending on the type of material used and the type of hole transport layer. In the photoelectric conversion element of the present invention, it is preferable that at least one of the first electrode and the second electrode is substantially transparent. It is preferable that the first electrode side is transparent and that incident light is incident from the first electrode side. In this case, it is preferable to use a light-reflecting material on the second electrode side, and metal, glass with a conductive oxide deposited on it, plastic, or a thin metal film is preferably used. Providing an anti-reflective layer on the incident light side is also an effective means.

[0200] <Second substrate> The second substrate is not particularly limited and can be any known substrate, such as glass, plastic film, or ceramic. The joint between the second substrate and the sealing member may have an uneven surface to improve adhesion. There are no particular restrictions on the method for forming the aforementioned uneven surface, and it can be appropriately selected depending on the purpose. Examples include sandblasting, water blasting, abrasive paper, chemical etching, and laser processing.

[0201] Means for improving the adhesion between the second substrate and the sealing member include, for example, removing organic matter from the surface or improving hydrophilicity. There are no particular limitations on the means for removing organic matter from the surface of the second substrate, and can be appropriately selected depending on the purpose, such as UV ozone cleaning or oxygen plasma treatment.

[0202] <Sealing member> The photoelectric conversion element of the present invention can and effectively utilize a sealing member capable of shielding at least the electron transport layer and the hole transport layer from the external environment of the photoelectric conversion element. In other words, it is preferable in the present invention to further include a sealing member that shields the photoelectric conversion layer from the external environment of the photoelectric conversion element. As the sealing member, any conventionally known material can be used as long as it can reduce the intrusion of excessive moisture, oxygen, etc., from the external environment into the sealed interior. Furthermore, the sealing member also has the effect of preventing mechanical damage caused by external pressure, and any conventionally known material can be used as long as it can achieve this effect.

[0203] The sealing methods can be broadly classified into "frame sealing," in which a sealing member is provided around the periphery of the power generation region composed of the photoelectric conversion layer of the photoelectric conversion element and bonded to the second substrate, and "surface sealing," in which a sealing member is provided over the entire power generation region and bonded to the second substrate. The former, "frame sealing," allows for the formation of a hollow space inside the sealing, making it possible to appropriately adjust the amount of moisture and oxygen inside the sealing, and also reduces the effect of electrode peeling because the second electrode is not in contact with the sealing member. On the other hand, the latter, "surface sealing," is excellent at preventing the intrusion of excessive water and oxygen from the outside, and because the bonding area with the sealing member is large, the sealing strength is high, making it particularly suitable when a flexible substrate is used as the first substrate.

[0204] There are no particular restrictions on the type of sealing member, and it can be appropriately selected according to the purpose. Examples include curing resins and low-melting-point glass resins. The curing resin is not particularly limited as long as it is a resin that hardens with light or heat, and can be appropriately selected according to the purpose, but acrylic resins and epoxy resins are among those that are preferably used.

[0205] The cured acrylic resin can be any known material, as long as it is obtained by curing a monomer or oligomer having an acrylic group in its molecule.

[0206] The cured epoxy resin can be any known material, as long as it is obtained by curing a monomer or oligomer having an epoxy group in its molecule. Examples of epoxy resins include water-dispersible, solvent-free, solid, heat-curing, curing agent-mixed, and UV-curing types. Among these, heat-curing and UV-curing types are preferred, with UV-curing types being more preferred. Even with UV-curing types, heating is possible, and it is preferable to heat them even after UV curing. Examples of the epoxy resins mentioned above include bisphenol A type, bisphenol F type, novolac type, cyclic aliphatic type, long-chain aliphatic type, glycidylamine type, glycidyl ether type, and glycidyl ester type. These may be used individually or in combination of two or more types.

[0207] The epoxy resin may preferably be mixed with a curing agent and various additives as needed. The curing agents are classified into amine-based, acid anhydride-based, polyamide-based, and other curing agents, and are selected as appropriate depending on the purpose. Examples of the amine-based curing agents include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone. Examples of the acid anhydride-based curing agents include phthalic anhydride, tetra and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, hetic anhydride, and dodecenyl succinic anhydride. Examples of other curing agents include imidazoles and polymer captans. These may be used individually or in combination of two or more.

[0208] Examples of the aforementioned additives include fillers, gap fillers, polymerization initiators, desiccants (hygroscopic agents), curing accelerators, coupling agents, softening agents, colorants, flame retardant aids, antioxidants, and organic solvents. Among these, fillers, gap fillers, curing accelerators, polymerization initiators, and desiccants (hygroscopic agents) are preferred, with fillers and polymerization initiators being more preferred.

[0209] The aforementioned filler is effective in suppressing the intrusion of moisture and oxygen, and also provides effects such as reduced volume shrinkage during curing, reduced outgassing during curing or heating, improved mechanical strength, and control of thermal conductivity and fluidity, making it very effective in maintaining stable output in various environments. In particular, the output characteristics and durability of photoelectric conversion elements are affected not only by the intrusion of moisture and oxygen, but also by the outgassing generated during the curing or heating of the sealing material, which cannot be ignored. In particular, the outgassing generated during heating has a significant impact on output characteristics when stored in high-temperature environments. In this case, by incorporating fillers, gap fillers, and desiccants into the sealing material, these materials themselves can suppress the intrusion of moisture and oxygen, and by reducing the amount of sealing material used, the effect of reducing outgassing can be obtained. This is effective not only during curing but also when the photoelectric conversion element is stored in a high-temperature environment.

[0210] There are no particular restrictions on the filler material, and it can be appropriately selected depending on the purpose. For example, inorganic fillers such as crystalline or amorphous silica, talc, alumina, aluminum nitride, silicon nitride, calcium silicate, and calcium carbonate are preferably used. These may be used individually or in combination of two or more types. The average primary particle size of the filler is preferably 0.1 μm to 10 μm, and more preferably 1 μm to 5 μm. When the amount added is within the preferred range, the effect of suppressing the intrusion of moisture and oxygen can be sufficiently obtained, the viscosity becomes appropriate, and it is also effective in improving adhesion to the substrate, degassing properties, and controlling the width of the sealing part and workability.

[0211] The content of the filler is preferably 10 to 90 parts by mass, and more preferably 20 to 70 parts by mass, per 100 parts by mass of the entire sealing member. By having the filler content within the above range, sufficient inhibition of moisture and oxygen penetration is obtained, the viscosity is appropriate, and adhesion and workability are also good.

[0212] The gap-sealing agent, also called a gap-controlling agent or spacer agent, makes it possible to control the gap in the sealed portion. For example, when sealing is performed by applying a sealing member to a first substrate or first electrode and then placing a second substrate on top of it, by mixing the gap-sealing agent with the epoxy resin, the gap in the sealed portion becomes the same size as the gap-sealing agent, making it easy to control the gap in the sealed portion. Any known material can be used as the gap filler, as long as it is granular, has a uniform particle size, and exhibits high solvent resistance and heat resistance. Materials with high affinity for epoxy resins and a spherical particle shape are preferred. Specifically, examples include glass beads, silica microparticles, and organic resin microparticles. These may be used individually or in combination of two or more. The average particle size of the gap filler can be selected according to the gap of the sealing portion to be set, but is preferably 1 μm to 100 μm, and more preferably 5 μm to 50 μm.

[0213] Examples of polymerization initiators include thermal polymerization initiators that initiate polymerization using heat, and photopolymerization initiators that initiate polymerization using light. The thermal polymerization initiator is a compound that generates active species such as radicals and cations upon heating. Specifically, azo compounds such as 2,2'-azobisbutyronitrile (AIBN) and peroxides such as benzoyl peroxide (BPO) are used. As thermal cationic polymerization initiators, benzenesulfonic acid esters and alkylsulfonium salts are used. On the other hand, for photopolymerization initiators, photocationic polymerization initiators are preferably used in the case of epoxy resins. When a photocationic polymerization initiator is mixed with epoxy resin and irradiated with light, the photocationic polymerization initiator decomposes, generating a strong acid, which causes polymerization of the epoxy resin, and the curing reaction proceeds. Photocationic polymerization initiators have the advantages of low volume shrinkage during curing, not being affected by oxygen inhibition, and having high storage stability. Examples of the photocationic polymerization initiators include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, metacerone compounds, and silanol-aluminum complexes.

[0214] Furthermore, photoacid generators that generate acid upon irradiation with light can also be used. These photoacid generators act as acids that initiate cationic polymerization, and examples include onium salts such as ionic sulfonium salts and iodonium salts, which consist of a cationic part and an anionic part. These may be used individually or in combination of two or more types.

[0215] The amount of polymerization initiator added may vary depending on the material used, but it is preferably 0.5 parts by mass to 10 parts by mass, and more preferably 1 part by mass to 5 parts by mass, per 100 parts by mass of the entire sealing member. By adding the polymerization initiator within the above range, curing can proceed properly, the remaining uncured material can be reduced, and excessive outgassing can be prevented, making it effective.

[0216] The aforementioned desiccant, also known as a hygroscopic agent, is a material that has the function of physically or chemically adsorbing and absorbing moisture. By incorporating it into the sealing member, it can be effective in further enhancing moisture resistance or reducing the effects of outgassing. The desiccant is preferably in particulate form, and examples include inorganic water-absorbing materials such as calcium oxide, barium oxide, magnesium oxide, magnesium sulfate, sodium sulfate, calcium chloride, silica gel, molecular sieves, and zeolites. Among these, zeolites, which have a high moisture absorption capacity, are preferred. These may be used individually or in combination of two or more.

[0217] The aforementioned curing accelerator, also known as a curing catalyst, is used to accelerate the curing speed and is mainly used with thermosetting epoxy resins. Examples of the curing accelerators include tertiary amines or tertiary amine salts such as DBU (1,8-diazabicyclo(5,4,0)-undecene-7) and DBN (1,5-diazabicyclo(4,3,0)-nonene-5), imidazole derivatives such as 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole, and phosphines or phosphonium salts such as triphenylphosphine and tetraphenylphosphonium·tetraphenylborate. These may be used individually or in combination of two or more.

[0218] The coupling agent has the effect of increasing molecular bonding strength, and examples of silane coupling agents include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N-(2-(vinylbenzylamino)ethyl)3-aminopropyltrimethoxysilane hydrochloride, and 3-methacryloxypropyltrimethoxysilane. These may be used individually or in combination of two or more.

[0219] Furthermore, epoxy resin compositions that are commercially available as sealing materials, sealants, or adhesives are known and can be effectively used in the present invention. In particular, epoxy resin compositions that have been developed and are commercially available for solar cells and organic EL elements can be used effectively in the present invention. Examples include TB3118, TB3114, TB3124, TB3125F (manufactured by ThreeBond Corporation), WorldRock5910, WorldRock5920, WorldRock8723 (manufactured by Kyoritsu Chemical Co., Ltd.), and WB90US(P) (manufactured by Moresco).

[0220] On the other hand, with low-melting-point glass resin, after coating, a firing process at around 550°C decomposes the resin components, and then it is melted using an infrared laser or the like to adhere closely to the glass substrate. At this time, the low-melting-point glass components diffuse into the metal oxide layer and are physically bonded, resulting in high sealing performance. Furthermore, because the resin components are eliminated, outgassing does not occur as with acrylic or epoxy resins, thus preventing degradation of the photoelectric conversion element, making it an effective choice.

[0221] In the present invention, a sheet-like sealing material can also be used as the sealing member. The aforementioned sheet-like sealing material is, for example, a sheet on which an epoxy resin layer has been formed in advance. The sheet may be made of glass or a film with high gas barrier properties, and corresponds to the second substrate in the present invention. By attaching the sheet-like sealing material onto the second electrode and then curing it, the sealing member and the second substrate can be formed in one step. By adjusting the formation pattern of the epoxy resin layer formed on the sheet, it is possible to create a structure with a hollow section, which is also effective. If the resin layer is formed over the entire surface of the sheet, it results in "surface sealing," but if the resin layer is patterned to create a hollow section inside the photoelectric conversion element, it results in "frame sealing."

[0222] There are no particular restrictions on the method for forming the sealing member, and it can be carried out according to known methods. For example, various methods such as the dispensing method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, letterpress printing, offset printing, intaglio printing, rubber printing, and screen printing can be used.

[0223] Furthermore, a passivation layer may be provided between the sealing member and the second electrode. The passivation layer is not particularly limited as long as the sealing member is arranged so as not to come into contact with the second electrode, and can be appropriately selected according to the purpose, but aluminum oxide, silicon nitride, silicon oxide, etc. are preferably used. By incorporating oxygen into the hollow space inside the encapsulation, it becomes possible to stably maintain the hole transport function of the hole transport layer over a long period of time, which can be effective in improving the durability of the photoelectric conversion element. In the present invention, it is preferable that the hollow space inside the encapsulation, which is formed by encapsulation, contains oxygen, and it is more preferable that the oxygen concentration is 10.0% by volume or more and 21.0% by volume or less.

[0224] The oxygen concentration in the hollow section can be controlled by sealing it within a glove box with adjusted oxygen concentration. Oxygen concentration can be adjusted by using a gas cylinder with a specific oxygen concentration or by using a nitrogen gas generator. The oxygen concentration inside the glove box can be measured using a commercially available oxygen meter or oxygen monitor. The oxygen concentration within the hollow portion formed by sealing can be measured, for example, by IVA (Internal Vapor Analysis). Specifically, this method involves loading a photoelectric conversion element into a high vacuum, drilling holes, and performing mass spectrometry on the generated gas and moisture. This method allows for the determination of the oxygen concentration contained inside the sealing of the photoelectric conversion element. There are quadrupole and time-of-flight mass spectrometers, with the latter offering more sensitive measurements.

[0225] The gas other than oxygen contained inside the seal is preferably an inert gas, such as nitrogen or argon. When sealing, it is preferable to control the dew point as well as the oxygen concentration inside the glove box, which is effective in improving output and durability. The dew point is defined as the temperature at which condensation begins when a gas containing water vapor is cooled. The dew point is not particularly limited, but is preferably 0°C or lower, and more preferably -20°C or lower. The lower limit is preferably -50°C or higher.

[0226] An example of the photoelectric conversion element of the present invention will be described below with reference to the drawings. However, the present invention is not limited to these examples, and for example, the number, position, shape, etc. of the following components that are not described in this embodiment are also included in the scope of the present invention.

[0227] <First Embodiment> Figure 1 is a schematic diagram showing an example of a photoelectric conversion element according to the first embodiment. In the photoelectric conversion element 101 of the first embodiment shown in Figure 1, a first electrode 2 is formed on a first substrate 1. An electron transport layer 4 is formed on the first electrode 2, and a photosensitizing compound 5 is adsorbed on the surface of the electron transport material constituting the electron transport layer 4. A hole transport layer 6 is formed on the upper part and inside the electron transport layer 4, and a second electrode 7 is formed on the hole transport layer 6. A second substrate 9 is placed above the second electrode 7, and the second substrate 9 is fixed between it and the first electrode 2 by a sealing member 8. At this time, the sealing member 8 can also be bonded to the first substrate 1 instead of the first electrode 2, which may be effective in improving airtightness. The photoelectric conversion element 101 of the first embodiment shown in Figure 1 has a hollow portion 10 between the second electrode 7 and the second substrate 9. By having a hollow portion 10, it is possible to control the amount of moisture and oxygen concentration within the hollow portion, thereby improving power generation performance and durability. Furthermore, since the second electrode 7 and the second substrate 9 are not in contact, peeling or damage of the second electrode 7 can be prevented. The oxygen concentration within the hollow portion is not particularly limited and can be freely controlled, but it is preferably between 10% and 21%. Although not shown in the diagram, the first electrode 2 and the second electrode 7 each have a path that provides electrical conductivity to the electrode extraction terminal.

[0228] <Second Embodiment> Figure 2 is a schematic diagram showing an example of a photoelectric conversion element according to the second embodiment. In the photoelectric conversion element 101 of the second embodiment shown in Figure 2, a hole blocking layer 3 is formed between the first substrate 1 and the electron transport layer 4. By forming the hole blocking layer 3, recombination of electrons and holes can be prevented, which is effective in improving power generation performance. The photoelectric conversion element shown in Figure 2 has a hollow portion 10 between the second electrode 7 and the second substrate 9, similar to Figure 1.

[0229] <Third Embodiment> Figure 3 is a schematic diagram showing an example of a photoelectric conversion element according to the third embodiment. In the photoelectric conversion element 101 of the third embodiment shown in Figure 3, the hollow portion 10 shown in Figure 2 is covered with a sealing member 8, thereby completely sealing the element. For example, it can be formed by applying the sealing member 8 to the entire surface of the second electrode 7 and then placing the second substrate 9 on top of it, or by using the aforementioned sheet-like sealing material. In this case, it is possible to provide a passivation layer 11 between the second electrode 7 and the sealing member 8, which can be effective in preventing the second electrode from peeling off. By covering almost the entire surface with a sealing member in this way, it is possible to increase the mechanical strength of the photoelectric conversion element.

[0230] (Method of manufacturing a photoelectric conversion element) The method for manufacturing the photoelectric conversion element according to the present invention is as follows: The process includes an electron transport layer formation step of forming an electron transport layer containing a compound represented by the following general formula (1) on a first electrode, and further includes other steps as necessary. [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka]

[0231] The present invention provides a method for manufacturing a photoelectric conversion element, which includes the steps of forming a first electrode on a first substrate, forming a photoelectric conversion layer on the first electrode, forming a second electrode on the photoelectric conversion layer, and further, if necessary, arranging other components such as a hole blocking layer and a sealing member.

[0232] In the method for manufacturing the photoelectric conversion element of the present invention, the first electrode, the photoelectric conversion layer, the second electrode, and other members and layers are the same as those described in the photoelectric conversion element of the present invention.

[0233] <Electron transport layer formation process> The electron transport layer formation step is a step of forming an electron transport layer containing a compound represented by the following general formula (1) on the first electrode. The electron transport layer formation step is a step of forming an electron transport layer by the same method as the electron transport layer formation method described in the photoelectric conversion element of the present invention.

[0234] <Other processes> Other steps include forming each layer using the same method as described for forming each layer in the photoelectric conversion element of the present invention.

[0235] (Photoelectric conversion module) The photoelectric conversion module has a plurality of photoelectric conversion elements of the present invention, and adjacent photoelectric conversion elements are electrically connected in series or in parallel. The photoelectric conversion module has, for example, a photoelectric conversion element arrangement region in which a plurality of photoelectric conversion elements are arranged adjacent to each other and connected in series or in parallel, and a photoelectric conversion layer including an electron transport layer and a hole transport layer is formed between the first electrode and the second electrode of the plurality of photoelectric conversion elements.

[0236] The photoelectric conversion module may have a plurality of photoelectric conversion elements. Furthermore, the plurality of photoelectric conversion elements may be connected in series and / or parallel, or they may include unconnected, independent photoelectric conversion elements. The configuration of each layer of the aforementioned photoelectric conversion module can be the same as that of the aforementioned photoelectric conversion element.

[0237] There are no particular restrictions on the structure of the photoelectric conversion module, and it can be appropriately selected according to the purpose. However, it is preferable that the first electrode, electron transport layer, and second electrode are separated in at least two adjacent photoelectric conversion elements, thereby reducing the risk of short circuits. On the other hand, the hole transport layer may be separated in at least two adjacent photoelectric conversion elements, or it may be in the form of a continuous layer in which the hole transport layers extend from one another.

[0238] Furthermore, in a photoelectric conversion module having at least two adjacent photoelectric conversion elements, it is preferable that the first electrode of one photoelectric conversion element and the second electrode of the other photoelectric conversion element are electrically connected by a conductive portion that penetrates the photoelectric conversion layer.

[0239] Furthermore, the photoelectric conversion module may have a pair of substrates and a photoelectric conversion element arrangement region between the pair of substrates that is connected in series or parallel, with the sealing member sandwiched between the pair of substrates. In particular, it is preferable that the photoelectric conversion module has a sealing member that shields the photoelectric conversion layers of the plurality of photoelectric conversion elements in the photoelectric conversion module from the external environment of the photoelectric conversion module.

[0240] An example of the photoelectric conversion element module of the present invention will be described below with reference to the drawings. However, the present invention is not limited to this, and for example, the number, position, shape, etc. of the following components that are not described in this embodiment are also included in the scope of the present invention.

[0241] <Fourth Embodiment> Figure 4 is a schematic diagram showing an example of the photoelectric conversion element module 102 of the present invention, and is an example showing a part of a photoelectric conversion element module that includes a plurality of photoelectric conversion elements connected in series. Figure 4 shows that after forming the hole transport layer 6, a through-hole 12 is formed, and then the second electrodes 7a and 7b are formed. This allows the material for the second electrodes to be introduced into the through-hole 12, enabling electrical connection with the first electrode 2b of the adjacent cell. Although not shown in Figure 4, the first electrode 2a and the second electrode 7b have paths that further extend to the electrodes or output terminals of adjacent photoelectric conversion elements.

[0242] The through-hole 12 may penetrate the first electrode 2 and reach the first substrate 1, or it may stop processing inside the first electrode 2 and not reach the first substrate 1. When the shape of the through-hole 12 is a micro-hole that penetrates the first electrode 2 and reaches the first substrate 1, if the total opening area of ​​the micro-hole becomes too large relative to the area of ​​the through-hole 12, the film cross-sectional area of ​​the first electrode 2 decreases, which increases the resistance value and may cause a decrease in photoelectric conversion efficiency. Therefore, the ratio of the total opening area of ​​the micro-hole to the area of ​​the through-hole 12 is preferably 5 / 100 or more and 60 / 100 or less.

[0243] There are no particular restrictions on the method for forming the through-holes 12, and a suitable method can be selected depending on the purpose. Examples include sandblasting, water blasting, abrasive paper, chemical etching, and laser processing. Among these, laser processing is preferred. This allows for the formation of fine holes without using sand, etching, or resist, and enables clean and reproducible processing. Furthermore, when forming the through-holes 12, at least one of the hole blocking layer 3, electron transport layer 4, hole transport layer 6, and second electrode 7 can be removed by impact peeling using laser processing. This eliminates the need to provide a mask during lamination, and allows for the removal and formation of fine through-holes 12 to be performed easily and simultaneously.

[0244] <Fifth Embodiment> Figure 5 is a schematic diagram showing an example of the photoelectric conversion element module 102 of the present invention. Unlike Figure 4, the hole transport layer 6 is separated from the adjacent photoelectric conversion elements, and each has an independent layer configuration. This suppresses electron diffusion, reduces leakage current, and can be effective in further improving durability.

[0245] (electronic equipment) The electronic device of the present invention comprises either the photoelectric conversion element of the present invention or the photoelectric conversion module, and a device that operates using the power generated by the photoelectric conversion performed by the photoelectric conversion element or the photoelectric conversion module, and further comprises other devices as necessary. Furthermore, the electronic device of the present invention comprises either the photoelectric conversion element of the present invention or the photoelectric conversion module, a rechargeable battery capable of storing the power generated by the photoelectric conversion of the photoelectric conversion element or the photoelectric conversion module, and a device that operates using the power stored in the rechargeable battery, and further comprises other devices as necessary.

[0246] (Power module) The power supply module of the present invention comprises the photoelectric conversion module and a power supply circuit (IC; Integrated Circuit), and further comprises other devices as necessary.

[0247] Next, a specific embodiment of an electronic device having the photoelectric conversion module and a device that operates using the power generated by these will be described.

[0248] Figure 6 is a block diagram of a personal computer mouse, which is an example of an electronic device according to the present invention. As shown in Figure 6, a photoelectric conversion module, a power supply IC, and a power storage device are combined, and the supplied power is connected to the power supply of the mouse's control circuit. This allows the power storage device to be charged when the mouse is not in use, and the mouse can be operated using that power, resulting in a mouse that does not require wiring or battery replacement. In addition, the elimination of batteries allows for weight reduction, which is an advantage.

[0249] Figure 7 is a schematic external view showing an example of the mouse shown in Figure 6. As shown in Figure 7, the photoelectric conversion module, power supply IC, and energy storage device are mounted inside the mouse, but the top of the photoelectric conversion element of the photoelectric conversion module is covered with a transparent housing so that light can shine on the photoelectric conversion element. It is also possible to mold the entire mouse housing from transparent resin. The arrangement of the photoelectric conversion element is not limited to this; for example, it can be placed in a position where light shines on it even when the mouse is covered with a hand, which may be preferable in some cases.

[0250] Next, other embodiments of electronic devices having the photoelectric conversion modules and devices that operate using the power generated by them will be described.

[0251] Figure 8 is a block diagram of a personal computer keyboard, which is an example of an electronic device according to the present invention. As shown in Figure 8, the photoelectric conversion element of the photoelectric conversion module, the power supply IC, and the energy storage device are combined, and the supplied power is connected to the power supply of the keyboard's control circuit. This allows the energy storage device to be charged when the keyboard is not in use, and the keyboard to operate using that power, resulting in a keyboard that does not require wiring or battery replacement. In addition, the elimination of batteries allows for weight reduction, which is an advantage.

[0252] Figure 9 is a schematic external view showing an example of the keyboard shown in Figure 8. As shown in Figure 9, the photoelectric conversion element, power supply IC, and energy storage device of the photoelectric conversion module are mounted inside the keyboard, but the top of the photoelectric conversion element is covered with a transparent housing so that light can reach it. It is also possible to mold the entire keyboard housing from transparent resin. The arrangement of the photoelectric conversion element is not limited to this. In the case of a small keyboard where there is little space to incorporate the photoelectric conversion element, it is also possible and effective to embed a small photoelectric conversion element in part of the key, as shown in Figure 10.

[0253] Next, other embodiments of electronic devices having the photoelectric conversion modules and devices that operate using the power generated by them will be described.

[0254] Figure 11 is a block diagram of a sensor as an example of the electronic device of the present invention. As shown in Figure 11, the photoelectric conversion element of the photoelectric conversion module, a power supply IC, and an energy storage device are combined, and the supplied power is connected to the power supply of the sensor circuit. This makes it possible to configure the sensor module without needing to connect to an external power supply or replace batteries. It can be applied to various sensors for sensing targets such as temperature, humidity, illuminance, human presence, CO2, acceleration, UV, noise, geomagnetic field, and atmospheric pressure, and is effective. As shown in Figure 12, the sensor module is configured to periodically sense the target and transmit the read data wirelessly to a PC or smartphone.

[0255] With the advent of the IoT (Internet of Things) society, the number of sensors is expected to increase dramatically. Replacing the batteries of these countless sensors one by one would be extremely time-consuming and impractical. Furthermore, sensors are often located in hard-to-reach places such as ceilings and walls, which further hinders work efficiency. The ability to supply power using a photoelectric conversion element offers significant advantages. In addition, the aforementioned photoelectric conversion module can obtain high output even in low light conditions, and its output has little dependence on the angle of incident light, resulting in greater installation flexibility.

[0256] Next, other embodiments of electronic devices having the photoelectric conversion modules and devices that operate using the power generated by them will be described.

[0257] Figure 12 is a block diagram of a turntable as an example of the electronic device of the present invention. As shown in Figure 12, a photoelectric conversion element, a power supply IC, and an energy storage device are combined, and the supplied power is connected to the power supply of the turntable circuit. This makes it possible to construct a turntable without needing to connect to an external power supply or replace batteries. Turntables are used, for example, in display cases for merchandise, but the power wiring is unsightly, and changing the batteries requires removing the displayed items, which is a time-consuming process. The aforementioned photoelectric conversion module can resolve these problems and is therefore effective.

[0258] The above describes the photoelectric conversion modules, electronic devices that operate using the power generated by them, and power supply modules. However, these are only a small part of the picture, and the photoelectric conversion modules are not limited to these applications.

[0259] <Application> The photoelectric conversion element and photoelectric conversion module of the present invention can function as a self-contained power source, and can operate devices using the power generated by photoelectric conversion. Since the photoelectric conversion module of the present invention can generate electricity when irradiated with light, there is no need to connect electronic devices to a power source or replace batteries. Therefore, it is possible to operate electronic devices even in places without power supply equipment, carry them around on the wearer, and operate electronic devices without replacing batteries even in places where battery replacement is difficult. Furthermore, when using dry cell batteries, electronic devices become heavier and larger, which can hinder installation on walls or ceilings, or portability. However, the photoelectric conversion module of the present invention is lightweight and thin, offering greater flexibility in installation and significant advantages when worn or carried around.

[0260] Thus, the photoelectric conversion module of the present invention can be used as a standalone power source and can be combined with various electronic devices. For example, it can be used in combination with a large number of electronic devices such as electronic calculators, watches, mobile phones, electronic organizers, electronic paper displays, computer accessories such as mice and keyboards, various sensor devices such as temperature and humidity sensors and motion sensors, transmitters such as beacons and GPS, auxiliary lights, and remote controls. The photoelectric conversion module of the present invention can generate electricity even in low light conditions, making it possible to generate electricity indoors and even in dimly lit, shaded areas, thus giving it a wide range of applications. Furthermore, it is highly safe, as it does not leak like dry cell batteries and does not pose a risk of accidental ingestion like button batteries. In addition, it can be used as an auxiliary power source to extend the continuous operating time of rechargeable or dry cell battery-powered electrical appliances. Thus, by combining the photoelectric conversion module of the present invention with a device that operates using the power generated by its photoelectric conversion, it is possible to create an electronic device that is lightweight, easy to use, offers high installation flexibility, requires no replacement, is highly safe, and is effective in reducing environmental impact.

[0261] Figure 13 shows a basic configuration diagram of an electronic device that combines the photoelectric conversion module of the present invention with a device that operates using the power generated by its photoelectric conversion. This device generates electricity when light is shone on the photoelectric conversion element, allowing power to be extracted. The device's circuitry can then operate using this power. However, because the output of the photoelectric conversion element in the photoelectric conversion module changes depending on the ambient light level, the electronic device shown in Figure 13 may not be able to operate stably. In this case, as shown in Figure 14, it is possible and effective to incorporate a power supply IC for the photoelectric conversion element between the photoelectric conversion element and the device's circuit to supply a stable voltage to the circuit side.

[0262] However, while the photoelectric conversion element in a photoelectric conversion module can generate power when illuminated with sufficient light intensity, it cannot obtain the desired power when the illumination is insufficient, which is a drawback of the photoelectric conversion element. In this case, as shown in Figure 15, by mounting a power storage device such as a capacitor between the power supply IC and the equipment circuit, it becomes possible to charge the power storage device with the excess power from the photoelectric conversion element. This makes it possible to supply power stored in the power storage device to the equipment circuit even when the illumination is too low or when no light hits the photoelectric conversion element, enabling stable operation. Thus, in electronic devices that combine the photoelectric conversion module of the present invention with equipment circuits, by combining a power supply IC and an energy storage device, it becomes possible to operate even in environments without a power supply, eliminate the need for battery replacement, and ensure stable operation, thereby maximizing the advantages of the photoelectric conversion element.

[0263] On the other hand, the photoelectric conversion module of the present invention can also be used as a power supply module, which is useful. For example, as shown in Figure 16, by connecting the photoelectric conversion module of the present invention with a power supply IC for the photoelectric conversion element, a DC power supply module can be configured in which the power generated by the photoelectric conversion of the photoelectric conversion element of the photoelectric conversion module can be supplied at a constant voltage level by the power supply IC.

[0264] Furthermore, as shown in Figure 17, by adding a power storage device to the power supply IC, it becomes possible to charge the power storage device with the power generated by the photoelectric conversion element of the photoelectric conversion module. This makes it possible to configure a power supply module that can supply power even when the illumination is too low or when no light hits the photoelectric conversion element. The power supply module of the present invention, shown in Figures 16 and 17, can be used as a power supply module without the need for battery replacement, unlike conventional primary batteries. [Examples]

[0265] The following describes embodiments of the present invention, but the present invention is not limited in any way to these embodiments.

[0266] [Synthesis method for compounds represented by (B1-6)] <Synthesis example of raw material 1 1a> [ka] 4-Iodoaniline (manufactured by Tokyo Chemical Industry Co., Ltd.: 10.95g), 1-Iodooctane (manufactured by Tokyo Chemical Industry Co., Ltd.: 39.6g), sodium carbonate (manufactured by Kanto Chemical Co., Ltd.: 10.6g), and dehydrated dimethylformamide (manufactured by Kanto Chemical Co., Ltd.: 150ml) were placed in a 500ml four-necked flask and heated and stirred at 120°C for 7 hours. The organic phase was then washed with water, extracted, and concentrated. Subsequently, column purification was performed using dichloromethane. The yield was 24.87 g. The obtained compound (13.3g) was placed in a 200ml four-necked flask with trimethylsilylacetylene (Tokyo Chemical Industries, Ltd.: 3.83g), CuI (Kanto Chemical Co., Ltd.: 114mg), and diisopropylamine (Tokyo Chemical Industries, Ltd.: 50ml). Palladium-tetrakis(triphenylphosphine) (Pd(PPh3)4, Tokyo Chemical Industries, Ltd.: 347mg) was added under an argon gas atmosphere, and the mixture was heated and stirred at 50°C for 3 hours. The organic phase was washed with water, extracted, and concentrated. Subsequently, methanol (manufactured by Kanto Chemical Co., Ltd.: 65 ml), dichloromethane (manufactured by Kanto Chemical Co., Ltd.: 65 ml), and sodium hydroxide (manufactured by Kanto Chemical Co., Ltd.: 15 g) were added to the obtained concentrate, and the mixture was stirred at room temperature for 2 hours. The organic phase was then washed with water, extracted, and concentrated. The yield was 5.12 g.

[0267] <Synthesis example 1b of raw material 2> [ka] 4,4-bis(2-ethylhexyl)-4H-cyclopenta-dithiophene (manufactured by Tokyo Chemical Industry Co., Ltd.: 5 g) was dissolved in anhydrous tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd.: 50 ml) and stirred at -78°C under an argon gas atmosphere. Next, 1.55 M n-butyllithium hexane (manufactured by Kanto Chemical Co., Ltd.: 9 ml) was added and the mixture was stirred at -78°C for 3 hours. Subsequently, a solution of tributyltin chloride (manufactured by Kanto Chemical Co., Ltd.: 5.25 g) diluted in anhydrous tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd.: 30 ml) was slowly added dropwise. The mixture was stirred at -78°C for 1 hour, then stirred at room temperature for 1 hour, and the organic phase was washed with water, extracted, and concentrated. The yield of purple oil was 9.6 g.

[0268] <Synthesis example 1c> [ka] 4,7-Dibromo-2,1,3-Benzothiazole (manufactured by Kanto Chemical Co., Ltd.: 4.7g), 4-Formylphenylbenzoic acid (manufactured by Kanto Chemical Co., Ltd.: 2.5g), potassium carbonate (manufactured by Kanto Chemical Co., Ltd.: 6.64g), tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd.: 100ml), and water (10ml) were placed in a 200ml four-necked flask and stirred under an argon gas atmosphere. Pd(PPh3)4 (manufactured by Kanto Chemical Co., Ltd.: 1.85g) was added, and the mixture was heated and stirred at 50°C for 10 hours. The organic phase was washed with water, extracted, and concentrated. The yield was 8.6g.

[0269] <Synthesis Example 1d> [ka] The aldehyde obtained in Synthesis Example 1c (Synthesis 3: 0.87 g), Pd(PPh3)2Cl2 (manufactured by Kanto Chemical Co., Ltd.: 47.7 mg), and toluene (manufactured by Kanto Chemical Co., Ltd.: 100 ml) were placed in a 200 ml four-necked flask and heated and stirred at 40°C under an argon gas atmosphere. Next, a solution of the tin compound obtained in Synthesis Example 1b of raw material 2 (Synthesis 2: 2.65 g) and toluene (manufactured by Kanto Chemical Co., Ltd.: 10 ml) was added dropwise, and reflux stirring was carried out for 2 hours. The organic phase was then washed with water, extracted, and concentrated. The yield was 4.8 g. The obtained concentrate was dissolved in dichloromethane (manufactured by Kanto Chemical Co., Ltd.: 100 ml), stirred at 3°C, NBS (manufactured by Kanto Chemical Co., Ltd.: 1 g) was added, and the mixture was stirred for 4 hours. The organic phase was washed with water and extracted to concentrate. Column purification (cyclohexane) yielded a red oil yield of 1.4 g.

[0270] <Synthesis Example 1e> [ka] The acetylene compound obtained in Synthesis Example 1a of Raw Material 1 (Synthesis 1: 0.73 g), the bromo compound obtained in Synthesis Example 1d (Synthesis 4: 1.4 g), tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd.: 30 ml), triethylamine (manufactured by Kanto Chemical Co., Ltd.: 5 ml), and CuI (manufactured by Kanto Chemical Co., Ltd.: 37 mg) were placed in a 100 ml four-necked flask and stirred under an argon gas atmosphere. Pd(PPh3)4 (manufactured by Kanto Chemical Co., Ltd.: 216 mg) was added, and reflux stirring was carried out for 1 hour. The organic phase was then washed with water, extracted, and concentrated. Column purification (dichloromethane / cyclohexane = 7 / 3 vol) was performed, followed by further purification using recycled GPC. The yield was 0.84 g. The entire purified product, cyanoacetic acid (manufactured by Kanto Chemical Co., Ltd.: 227 mg), ammonium acetate (manufactured by Kanto Chemical Co., Ltd.: 207 mg), and acetic acid (manufactured by Kanto Chemical Co., Ltd.: 50 ml) were placed in a 100 ml four-necked flask, and reflux stirring was carried out for 2 hours. The organic phase was then washed with water, extracted, and concentrated. Column purification (dichloromethane / methanol = 8 / 2 vol) was performed, followed by dissolution in dichloromethane and reprecipitation with methanol. The purified product was dried to obtain the compound represented by (B1-6). The product yield was 0.62 g. Furthermore, the FT-IR identification data for the compounds represented above (B1-6) is shown in Figure 19A.

[0271] Next, an example of the photoelectric conversion element of the present invention will be shown.

[0272] (Example 1) <Fabrication of photoelectric conversion element 1> On a glass substrate, which served as the first substrate, indium-doped tin oxide (ITO) and niobium-doped tin oxide (NTO), which served as the first electrodes, were sequentially deposited by sputtering. Next, a dense layer (average thickness 20 nm) made of titanium oxide was formed as a hole-blocking layer by reactive sputtering with oxygen gas.

[0273] Next, titanium dioxide (Greatcell Solar Materials, 18NR-T) paste was screen-printed onto the hole blocking layer to an average thickness of approximately 1.2 μm. After drying at 120°C, it was fired in air at 500°C for 30 minutes to form a porous electron transport layer. A glass substrate on which an electron transport layer was formed was immersed in a solution prepared by adding a acetonitrile / t-butanol (volume ratio 1:1) mixture to a photosensitizing compound (0.2 mM) represented by B1-1 below and stirring. The solution was then left to stand in the dark for 1 hour to allow the photosensitizing compound to adsorb onto the surface of the electron transport layer. Furthermore, photosensitized compound B1-1 was synthesized in the same manner as "(B1-6) synthesis method," except that the corresponding alkyl group of photosensitized compound B1-1 was changed in "Synthesis Example 1a of Raw Material 1," "Synthesis Example 1b of Raw Material 2," and "Synthesis Example 1c." [ka] (B1-1)

[0274] Next, 150 mM of the organic hole transport material represented by D-7 (SHT-263, manufactured by Merck KGaA), 70 mM of lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI, manufactured by Kishida Chemical Co., Ltd.) as a lithium salt, 135 mM of the basic compound 4-pyrrolidinopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 15 mM of the oxidizing agent FK209 (manufactured by Aldrich), represented by F-11, were added to 1 mL of chlorobenzene solution to prepare the hole transport layer coating solution 1.

[0275] Next, a hole transport layer with an average thickness of approximately 500 nm was coated onto the electron transport layer on which the photosensitizing compound was adsorbed using hole transport layer coating solution 1 by die coating. The hole transport layer coating solution was applied onto the electron transport layer on which the photosensitizing compound was adsorbed, and then heated and dried in an oven at atmospheric pressure at 60°C for 60 minutes. Subsequently, the edges of the glass substrate on which the sealing member is provided were etched using laser processing, and through holes for connecting to the ITO layer, which will serve as the terminal extraction area, were formed using further laser processing.

[0276] After attaching a mask to the edges of the glass substrate and between the cells, silver was vacuum-deposited to form a second electrode of approximately 70 nm.

[0277] UV-curing resin (TB3118, manufactured by ThreeBond Holdings Co., Ltd.) was applied to the edge of the glass substrate using a dispenser (2300N, manufactured by San-ei Tech Co., Ltd.) so that the power generation area was surrounded. Then, the substrate was moved into a glove box adjusted to a dew point of minus 40°C and an oxygen concentration of 10% by volume. A cover glass, which served as the second substrate, was placed on top of the UV-curing resin, cured by UV irradiation, and then heated at 80°C for 60 minutes. In this way, the power generation area was sealed, and a photoelectric conversion element 1 as shown in Figure 1 was fabricated.

[0278] Next, the performance of the fabricated photoelectric conversion elements was evaluated as follows. The results are shown in Table 1.

[0279] <Evaluation of photoelectric conversion elements> The obtained photoelectric conversion elements were evaluated for their IV characteristics using a solar cell evaluation system (As-510-PV03, manufactured by NF Circuit Design Block Co., Ltd.) under 2700K warm-color LED illumination adjusted to 500 lux, and the initial open-circuit voltage Voc1 (V) and maximum output power Pmax1 (μW / cm²) were determined. 2 ) was sought. Next, the sample was irradiated under sunlight (AM1.5G) at 25°C for 150 hours, and the IV characteristics under the same conditions were evaluated again. The open-circuit voltage Voc2 and maximum output power Pmax2 (μW / cm²) after sunlight irradiation were then determined. 2 The following measurements were taken, and the respective maintenance rates Voc2 / Voc1(%) and Pmax2 / Pmax1(%) were determined.

[0280] (Examples 2-7) Photoelectric conversion elements 2 to 7 were fabricated in the same manner as in Example 1, except that the photosensitizing compound was changed to the photosensitizing compound shown in Table 1. The performance of photoelectric conversion elements 2 to 7 was also evaluated in the same manner as photoelectric conversion element 1. The results are shown in Table 1. The photosensitizing compounds B1-2 and B1-5 to B1-9 shown in Table 1 are as follows. Furthermore, the photosensitizing compounds B1-2 and B1-5 to B1-9 were synthesized in the same manner as in "(B1-6) synthesis method," except that the corresponding alkyl groups of the photosensitizing compounds B1-2 and B1-5 to B1-9 were changed in "Synthesis Example 1a of Raw Material 1," "Synthesis Example 1b of Raw Material 2," and "Synthesis Example 1c." [ka] (B1-2) [ka] (B1-5) [ka] (B1-7) [ka] (B1-8) [ka] (B1-9)

[0281] (Example 8) In Example 4, a photoelectric conversion element 8 was fabricated in the same manner as in Example 4, except that a flocculation dissociation agent (5 mM) represented by B2-1 was further added to the solution of the photosensitizing compound. The performance of the photoelectric conversion element 8 was also evaluated in the same manner as that of the photoelectric conversion element 1. The results are shown in Table 1.

[0282] (Example 9) In Example 8, photoelectric conversion element 9 was fabricated in the same manner as in Example 8, except that lithium bis(trifluoromethanesulfonylimide) (Li-TFSI) was replaced with lithium (fluoromethanesulfonyl)(trifluoromethanesulfonyl)imide (Li-FTFSI, manufactured by Tokyo Chemical Industry Co., Ltd.). The performance of photoelectric conversion element 9 was also evaluated in the same manner as in photoelectric conversion element 1. The results are shown in Table 1.

[0283] (Example 10) In Example 9, photoelectric conversion element 10 was fabricated in the same manner as in Example 9, except that 4-pyrrolidinopyridine was replaced with a basic compound represented by H-1. The performance of photoelectric conversion element 10 was also evaluated in the same manner as in photoelectric conversion element 1. The results are shown in Table 1.

[0284] (Example 11) In Example 9, photoelectric conversion element 11 was fabricated in the same manner as in Example 9, except that 4-pyrrolidinopyridine was replaced with a basic compound represented by H-3. The performance of photoelectric conversion element 11 was also evaluated in the same manner as in photoelectric conversion element 1. The results are shown in Table 1.

[0285] (Comparative Example 1) In Example 1, a photoelectric conversion element 12 was fabricated in the same manner as in Example 1, except that the photosensitizing compound was changed to the compound represented by compound A below (XY3b (manufactured by Dyenamo)). The performance of the photoelectric conversion element 12 was also evaluated in the same manner as in photoelectric conversion element 1. The results are shown in Table 1. [ka] ...Compound A

[0286] (Comparative Example 2) In Example 1, a photoelectric conversion element 13 was fabricated in the same manner as in Example 1, except that the photosensitizing compound was changed to the compound shown as compound B below. The performance of the photoelectric conversion element 13 was also evaluated in the same manner as that of the photoelectric conversion element 1. The results are shown in Table 1. [ka] ...Compound B Compound B was synthesized based on the method described in the following paper (J. Phys. Chem. C 2015, 119, 24282-24289).

[0287] [Table 1]

[0288] The results in Table 1 show that, compared to Comparative Examples 1 and 2, Examples 1 to 11 can suppress the degradation of performance in low-light conditions even after being exposed to sunlight. It has been found that the association state and interactions between dyes are extremely important for solid-state dye-sensitized solar cells to efficiently convert photoelectric energy under sunlight irradiation conditions.

[0289] Examples of the present invention are as follows: <1> This compound is characterized by being represented by the following general formula (1). [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka] <2> The above general formula (1) is represented by the following general formula (2), <1> It is the compound described in [reference]. [ka] ...General formula (2) (In general formula (2), R2 represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka] <3> This is a compound for photoelectric conversion elements characterized by being represented by the following general formula (1). [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka] <4> The above general formula (1) is represented by the following general formula (2), <3> This is a compound for photoelectric conversion elements as described in [reference]. [ka] ...General formula (2) (In general formula (2), R2 represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka] <5> First electrode and, An electron transport layer containing a compound represented by the following general formula (1), Hall transport layer, This is a photoelectric conversion element characterized by having a second electrode. [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka] <6> The electron transport layer contains titanium oxide particles having the compound represented by the general formula (1), and has a porous structure. <5> This is the photoelectric conversion element described in [reference]. <7> The above general formula (1) is a compound represented by the following general formula (2), <5> from <6> It is a photoelectric conversion element described in any of the following. [ka] ...General formula (2) (In general formula (2), R2 represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka] <8> The electron transport layer further contains a compound represented by the following general formula (3), <5> from <7> It is a photoelectric conversion element described in any of the following. [ka] ...General formula (3) (In general formula (3), n represents a natural number from 1 to 3, and Ar3 represents an optionally substituted phenyl group or naphthyl group.) <9> The hole transport layer contains lithium (fluorosulfonyl) (trifluoromethanesulfonyl)imide, <5> from <8> It is a photoelectric conversion element described in any of the following. <10> The hole transport layer contains a pyridine compound represented by the following general formula (A1), <5> from <9> It is a photoelectric conversion element described in any of the following. [ka] ...General formula (A1) (In general formula (A1), Ar1 and Ar2 represent aryl groups which may have substituents.) <11> The aforementioned <5> from <10> This is an electronic device characterized by having a photoelectric conversion element as described in any of the above. <12> The aforementioned <5> from <10> This power module is characterized by having a photoelectric conversion element as described in any of the above and a power supply IC. <13> A method for manufacturing a photoelectric conversion element, characterized by including an electron transport layer formation step of forming an electron transport layer containing a compound represented by the following general formula (1) on a first electrode. [ka] ...General formula (1) (In general formula (1), R1 and R2 represent linear or branched alkyl groups having 4 to 12 carbon atoms, and X represents one of the following structures.) [ka] [ka] [ka] [ka]

[0290] The aforementioned <1> from <2> A compound described in any of the above, <3> from <4> A photoelectric conversion element compound as described in any of the above, <5> from <10> A photoelectric conversion element as described in any of the above, <11> The electronic equipment described above, <12> The power supply module described above, and the above <13> The method for manufacturing a photoelectric conversion element described herein can solve the problems of the conventional method and achieve the objectives of the present invention. [Prior art documents] [Patent Documents]

[0291] [Patent Document 1] Japanese Patent Publication No. 2018-113305 [Explanation of Symbols]

[0292] 1. First substrate 2, 2a, 2b First electrodes 3 Hole Blocking Layer 4 Electron transport layer 5. Photosensitized compounds 6 Hole transport layer 7, 7a, 7b Second electrodes 8 Sealing member 9. Second substrate 10 Hollow part 11 Passivation Layer 12 Penetration section (conductive section) 101 Photoelectric conversion element 102 Photoelectric Conversion Module

Claims

1. A compound characterized by being represented by the following general formula (1). 【Chemistry 1】 ...General formula (1) (In general formula (1), R １ and R ２ (where represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 【Transformation 5】

2. The compound according to claim 1, wherein the general formula (1) is represented by the following general formula (2). 【Transformation 6】 ...General formula (2) (In general formula (2), R ２ (where represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) 【Transformation 7】 【Transformation 8】 【Chemistry 9】 【Chemistry 10】

3. A compound for photoelectric conversion elements characterized by being represented by the following general formula (1). 【Chemistry 11】 ...General formula (1) (In general formula (1), R １ and R ２ (where represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) 【Chemistry 12】 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】

4. The compound for a photoelectric conversion element according to claim 3, wherein the general formula (1) is represented by the following general formula (2). 【Chemistry 16】 ...General formula (2) (In general formula (2), R ２ (where represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) 【Chemistry 17】 [Chemistry 18] 【Chemistry 19】 【Chemistry 20】

5. First electrode and, An electron transport layer containing a compound represented by the following general formula (1), Hall transport layer, A photoelectric conversion element characterized by having a second electrode. 【Chemistry 21】 ...General formula (1) (In general formula (1), R １ and R ２ (where represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents one of the following structures.) 【Chemistry 22】 【Chemistry 23】 【Chemistry 24】 【Chemistry 25】

6. The photoelectric element according to claim 5, wherein the electron transport layer contains titanium oxide particles on which the compound represented by the general formula (1) is chemically or physically adsorbed, and has a porous structure.

7. The photoelectric conversion element according to any one of claims 5 to 6, wherein the general formula (1) is a compound represented by the following general formula (2). 【Chemistry 26】 ...General formula (2) (In general formula (2), R ２ represents a linear or branched alkyl group having 4 to 12 carbon atoms, and X represents any of the following structures.) 【Chemistry 27】 【Chemistry 28】 【Chemistry 29】 【Transformation 30】

8. The photoelectric conversion element according to any one of claims 5 to 7, wherein the hole transport layer contains lithium (fluorosulfonyl) (trifluoromethanesulfonyl)imide.

9. An electronic device characterized by having a photoelectric conversion element according to any one of claims 5 to 8.

10. A power supply module characterized by having a photoelectric conversion element according to any one of claims 5 to 8 and a power supply IC.

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