Photoelectric conversion module, method for manufacturing a photoelectric conversion module, electronic device, power supply module, and building material

Abstract

To provide a photoelectric conversion module that has high photoelectric conversion efficiency and can suppress short circuits between photoelectric conversion elements even when multiple photoelectric conversion elements are electrically connected. [Solution] A photoelectric conversion module having a substrate and a plurality of photoelectric conversion elements on the substrate, including a first photoelectric conversion element and a second photoelectric conversion element, wherein each photoelectric conversion element has a first electrode, a laminate, and a second electrode on the substrate in this order, the laminate has an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer, the second electrode of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are electrically connected, and the photoelectric conversion module further has a high-resistivity layer between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element, the high-resistivity layer having a higher resistivity than the hole transport layer of the second photoelectric conversion element.

Description

[Technical Field]

[0001] The present invention relates to a photoelectric conversion module, a method for manufacturing a photoelectric conversion module, an electronic device, a power supply module, and building materials. [Background technology]

[0002] In recent years, solar cells, which utilize photoelectric conversion elements, are expected to have a wide range of applications, not only from the perspective of replacing fossil fuels and combating global warming, but also as self-sustaining power sources that do not require battery replacement or power wiring. Furthermore, solar cells as self-sustaining power sources are attracting significant attention as one of the energy harvesting technologies required for IoT (Internet of Things) devices and artificial satellites.

[0003] In addition to conventionally used inorganic solar cells made of silicon and other materials, there are also organic solar cells such as dye-sensitized solar cells, organic thin-film solar cells, and perovskite solar cells. Perovskite solar cells are advantageous in terms of improved safety and reduced manufacturing costs because they can be manufactured using conventional printing methods without using electrolytes containing organic solvents.

[0004] Furthermore, a method for manufacturing a photoelectric conversion element is known, comprising the steps of: coating a transparent electrode with a solution containing a first P-type organic semiconductor and an oxidizing agent capable of oxidizing the first P-type organic semiconductor, drying the solution, and oxidizing the first P-type organic semiconductor with the oxidizing agent to form a hole injection layer (see, for example, Patent Document 1). [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The objective is to provide a photoelectric conversion module that has high photoelectric conversion efficiency and can suppress short circuits between photoelectric conversion elements even when multiple photoelectric conversion elements are electrically connected. [Means for solving the problem]

[0006] The photoelectric conversion module of the present invention is a photoelectric conversion module having a substrate and a plurality of photoelectric conversion elements on the substrate, including a first photoelectric conversion element and a second photoelectric conversion element, wherein each photoelectric conversion element has a first electrode, a laminate, and a second electrode on the substrate in this order, the laminate has an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer, the second electrode of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are electrically connected, and the photoelectric conversion module further has a high-resistivity layer between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element, the high-resistivity layer having a higher resistivity than the hole transport layer of the second photoelectric conversion element. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a photoelectric conversion module that has high photoelectric conversion efficiency and can suppress short circuits between photoelectric conversion elements even when multiple photoelectric conversion elements are electrically connected. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing an example of a photoelectric conversion element according to the first embodiment. [Figure 2] This is a schematic diagram showing an example of a photoelectric conversion module according to the first embodiment. [Figure 3] This is a schematic diagram showing an example of a photoelectric conversion module according to the first embodiment. [Figure 4] This is a schematic diagram showing an example of a photoelectric conversion element according to the second embodiment. [Figure 5] This is a schematic diagram showing an example of a photoelectric conversion module according to the second embodiment. [Figure 6] Figure 5 is a top view of the photoelectric conversion module shown. [Figure 7] Figure 5 is a top view of the photoelectric conversion module shown, cut along the dotted line A-A'. [Figure 8] This is a schematic diagram showing an example of a photoelectric conversion element according to the third embodiment. [Figure 9]It is a schematic diagram showing an example of a photoelectric conversion element of the fourth embodiment. [Figure 10] It is a schematic diagram showing an example of a photoelectric conversion module of the fourth embodiment. [Figure 11] It is a schematic diagram showing an example of an electronic device having the photoelectric conversion element of this embodiment. [Figure 12] It is a schematic diagram showing an example of a power supply module having the photoelectric conversion element of this embodiment. [Figure 13] It is a schematic diagram showing an example of a building material having the photoelectric conversion element of this embodiment.

Embodiments for Carrying Out the Invention

[0009] (Photoelectric conversion element) A photoelectric conversion element means an element that can convert light energy into electrical energy or convert electrical energy into light energy, and is applied to solar cells, photodiodes, etc. The photoelectric conversion element of this embodiment has a first electrode, a laminate, a second electrode provided facing the first electrode through the laminate, and a high-resistance layer covering at least a part of the side surface of the hole transport layer, and the resistivity of the high-resistance layer is higher than the resistivity of the hole transport layer. The laminate has an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer. The photoelectric conversion element may have other layers such as a first substrate and a passivation layer as required.

[0010] (Photoelectric conversion module) The photoelectric conversion module of the present embodiment is a photoelectric conversion module having a substrate and a plurality of photoelectric conversion elements including a first photoelectric conversion element and a second photoelectric conversion element on the substrate. Each of the photoelectric conversion elements has, in this order, a first electrode, a laminate, and a second electrode on the substrate. The laminate has an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer. The second electrode of the first photoelectric conversion element is electrically connected to the first electrode of the second photoelectric conversion element. The photoelectric conversion module further has a high-resistance layer having a resistivity higher than that of the hole transport layer of the second photoelectric conversion element between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element. At least one of the plurality of photoelectric conversion elements in the photoelectric conversion module may be the photoelectric conversion element of the present embodiment, and all of them may be the photoelectric conversion elements of the present embodiment. By having all of the plurality of photoelectric conversion elements in the photoelectric conversion module as the photoelectric conversion elements of the present embodiment, the effect of suppressing the short circuit between the photoelectric conversion elements can be enhanced. The plurality of photoelectric conversion elements in the photoelectric conversion module are electrically connected in series and / or in parallel. Among them, it is preferable that the plurality of photoelectric conversion elements are electrically connected in series, and it is preferable that the photoelectric conversion element of the present embodiment is connected in series with another adjacent photoelectric conversion element. The photoelectric conversion module preferably has, for example, a plurality of photoelectric conversion elements on a first substrate, a second substrate different from the first substrate, and a sealing member, and has other members as required.

[0011] The photoelectric conversion module of the present invention is an invention that finds the following problems in the prior art and aims to solve the following problems. Regarding conventional photoelectric conversion modules, it is known that the output voltage can be increased by electrically connecting multiple spatially divided photoelectric conversion elements to form a series circuit. The divided portions of adjacent photoelectric conversion elements need to be as narrow as possible in order to maximize the power generation area, and it is preferable to keep the distance between adjacent photoelectric conversion elements to 200 μm or less. However, if the distance between photoelectric conversion elements becomes too narrow, a short circuit occurs between adjacent photoelectric conversion elements, i.e., conduction occurs in undesirable areas, which leads to a decrease in power generation efficiency.

[0012] As a result of investigating the above problems, the present inventors have found that a photoelectric conversion module can be provided that suppresses short circuits between photoelectric conversion elements even when multiple photoelectric conversion elements are electrically connected, by further providing a high-resistivity layer between the second photoelectric conversion element and the second photoelectric conversion element, the photoelectric conversion module having a substrate and a plurality of photoelectric conversion elements including a first photoelectric conversion element and a second photoelectric conversion element on the substrate, each photoelectric conversion element having a first electrode, a laminate and a second electrode in this order on the substrate, the laminate having an electron transport layer, a hole transport layer and a photoelectric conversion layer between the electron transport layer and the hole transport layer, the second electrode of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element being electrically connected, and the present invention has been completed.

[0013] The following describes the components included in the photoelectric conversion module and photoelectric conversion element of this embodiment. The photoelectric conversion module of the present invention has a substrate and a plurality of photoelectric conversion elements on the substrate.

[0014] <First circuit board> The photoelectric conversion element in this embodiment has a first substrate. There are no particular restrictions on the shape, structure, or size of the first substrate, and it can be appropriately selected according to the purpose.

[0015] The material of the first substrate is not particularly limited as long as it has 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.

[0016] The substrate may be provided on either the outermost side of the first electrode of the photoelectric conversion element, or on the outermost side of the second electrode, or both. Hereinafter, the substrate located on the outermost side of the first electrode will be referred to as the first substrate, the substrate located on the outermost side of the second electrode will be referred to as the second substrate, and the first substrate and the second substrate will be collectively referred to as the substrate.

[0017] There are no particular restrictions on the average thickness of the substrate; it can be appropriately selected depending on the purpose, for example, it can be between 50 μm and 5 mm. The average thickness of the substrate can be measured using, for example, a tactile thickness gauge, caliper, or digital thickness gauge.

[0018] <First electrode> There are no particular restrictions on the shape, structure, and size of the first electrode, and it can be appropriately selected according to the purpose. There are no particular restrictions on the structure of the first electrode; it may be a single-layer structure or a structure in which multiple materials are layered.

[0019] The material of the first electrode is not particularly limited as long as it is conductive, and can be appropriately selected according to the purpose. Examples include transparent conductive metal oxides, carbon, and metals. Examples of 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 (hereinafter referred to as "AZO"), indium zinc oxide, niobium titanium oxide, and the like. Examples of carbon include carbon black, carbon nanotubes, graphene, and fullerenes. Examples of 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, and ITO, FTO, ATO, NTO, and AZO are more preferred.

[0020] 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 integrated commercially available products include FTO-coated glass, ITO-coated glass, AZO-coated glass, FTO-coated transparent plastic film, and ITO-coated transparent plastic film. These may be used individually, or two or more may be mixed or layered together. Alternatively, electrodes from a commercially available integrated product may be appropriately processed to create a substrate on which multiple first electrodes are formed.

[0021] There are no particular restrictions on the average thickness of the first electrode, and it can be appropriately selected depending on the purpose. Preferably, it is 5 nm to 100 μm, and more preferably 50 nm to 10 μm. The average thickness can be measured using, for example, a contact-type film thickness gauge or a scanning electron microscope (SEM).

[0022] Methods for forming the first electrode include sputtering, vapor deposition, and spraying.

[0023] <Laminate> The layers located between the first electrode and the second electrode (described later) are collectively referred to as a laminate. The laminate has an electron transport layer, a photoelectric conversion layer, and a hole transport layer, and may also have other layers. Examples of other layers include a passivation layer.

[0024] <<Electron transport layer>> The electron transport layer is a layer that transports electrons generated in the photoelectric conversion layer (described later) to the first electrode. For this reason, in the case of a forward-type photoelectric conversion element, the electron transport layer is preferably located adjacent to the first electrode, and in the case of an inverted-type photoelectric conversion element, it is preferably located adjacent to the second electrode.

[0025] There are no particular restrictions on the shape or size of the electron transport layer; it can be appropriately selected according to the purpose. Furthermore, the structure of the electron transport layer may be a single layer or a multilayer structure in which multiple layers are stacked.

[0026] The electron transport layer contains electron transport material. There are no particular restrictions on the electron transport material; it can be appropriately selected according to the purpose, but semiconductor materials are preferred.

[0027] There are no particular restrictions on the semiconductor material; examples include elemental semiconductors, compound semiconductors, and compounds containing electron-withdrawing organic materials (N-type organic semiconductors). Examples of single-component semiconductors include silicon and germanium. Examples of compound semiconductors include metallic chalcogenides. Examples of metallic chalcogenides include metallic oxides (oxide semiconductors), metallic sulfides, metallic selenides, and metallic tellurides. Examples of metal oxides (oxide semiconductors) include those of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum. Examples of metal sulfides include those of cadmium, zinc, lead, silver, antimony, bismuth, and copper-indium. Examples of metal selenides include selenides of cadmium, lead, and copper-indium. Examples of metallic tellurides include tellurides of cadmium and other metals. Other compound semiconductors include, for example, phosphides of zinc, gallium, indium, and cadmium; and gallium arsenide. Among these, metal oxides (oxide semiconductors) are preferred, and it is more preferable that they contain at least one of titanium oxide, zinc oxide, tin oxide, and niobium oxide, with the presence of tin oxide being particularly preferred. Examples of electron-withdrawing organic materials include imide derivatives, fullerenes, and fullerene derivatives. Among these, fullerene derivatives are preferred from the viewpoint of charge separation and charge transport.

[0028] The semiconductor material and electron-withdrawing organic material used as electron transport 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.

[0029] The electron transport layer preferably contains at least one of the following compounds on the electron transport material on the surface facing the photoelectric conversion layer: a phosphonic acid compound, a boronic acid compound, a sulfonic acid compound, a silyl halide compound, and an alkoxysilyl compound. By containing these compounds on the electron transport material on the surface facing the photoelectric conversion layer, it is expected that the physical properties of the interface between the electron transport layer and the photoelectric conversion layer can be controlled. In other words, by coating the electron transport material with these compounds on the surface of the electron transport layer facing the photoelectric conversion layer, the resistivity of the interface between the electron transport layer and the photoelectric conversion layer is reduced, and it is expected that electron transfer will be smoother. These compounds may be bonded to electron transport materials. Examples of such bonds include covalent bonds and ionic bonds.

[0030] The compound contained on the surface of the electron transport layer preferably contains nitrogen atoms, in terms of compatibility with the photoelectric conversion layer (perovskite layer) described later. Examples of compounds contained on the surface of the electron transport layer include methylphosphonic acid, phenylphosphonic acid, phenethylphosphonic acid, (1-aminoethyl)phosphonic acid, (2-aminoethyl)phosphonic acid, methanesulfonic acid, benzenesulfonic acid, 2-thienylboronic acid, methyltrichlorosilane, and n-hexyltriethoxysilane.

[0031] There are no particular restrictions on the average thickness of the electron transport layer, and it can be appropriately selected depending on the purpose. A thickness of 5 nm to 1 μm is preferred, and a thickness of 10 nm to 700 nm is more preferred.

[0032] Methods for forming a thin film of electron transport material in an electron transport layer include, for example, a method for forming a thin film of electron transport material in a vacuum (vacuum deposition method) and a wet deposition method. Examples of vacuum thin-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). One example of a wet film-forming method is the sol-gel method. The sol-gel method involves preparing a gel from a solution through chemical reactions such as hydrolysis, polymerization, and condensation, and then promoting densification through heat treatment.

[0033] One method for applying a compound to an electron transport material is to coat a thin film of the electron transport material with a solution containing the compound and then dry it. Methods for applying solutions containing compounds include, for example, the dipping method, spraying method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, and inkjet method.

[0034] <<Photoelectric conversion layer>> The photoelectric conversion layer is provided between the electron transport layer and the hole transport layer, which will be described later. A layer other than the photoelectric conversion layer may be provided between the electron transport layer and the hole transport layer. In other words, the photoelectric conversion layer does not have to be in contact with the electron transport layer and the hole transport layer. As long as the photoelectric conversion layer is a layer that performs photoelectric conversion, there are no particular restrictions, and it can be appropriately selected according to the purpose, for example, a perovskite layer, a bulk heterojunction layer, etc.

[0035] <<<Perovskite layer>>> The perovskite layer contains a perovskite compound and has the function of separating charges when irradiated with light. Since the perovskite layer absorbs light and sensitizes the electron transport layer, it is preferable to place it adjacent to the electron transport layer. There are no particular restrictions on the shape or size of the perovskite layer; it can be appropriately selected according to the purpose.

[0036] Perovskite compounds are composite materials of organic and inorganic compounds, and are represented by the following general formula (1). XαYβZγ...General formula (1) However, in general formula (1), the ratio of α:β:γ is 3:1:1, where β and γ represent integers greater than 1, X represents a halogen atom, Y represents a monovalent cation, and Z represents a metal ion. Note that even if the above ratio does not strictly match due to crystal defects, etc., it is acceptable as long as it functions as a perovskite layer. In general formula (1), X is not particularly limited as long as it is an element belonging to Group 17 of the periodic table as defined by the International Union of Pure and Applied Chemistry (IUPAC), such as chlorine, bromine, and iodine. These can be used individually or in combination of two or more. Examples of Y in general formula (1) include monovalent organic cations and monovalent inorganic cations. By including at least two types of monovalent organic cations and monovalent inorganic cations in general formula (1), the crystal structure of the perovskite layer becomes more complex, thereby improving the durability of the perovskite layer. Examples of monovalent organic cations include alkylamine compound ions. Examples of alkylamine compound ions include methylammonium, ethylammonium, n-butylammonium, and formamidinium. Examples of monovalent inorganic cations include cesium ions, potassium ions, and rubidium ions. In general formula (1), there are no particular restrictions on Z, and it can be appropriately selected depending on the purpose. Examples include metal ions such as lead, indium, antimony, tin, copper, and bismuth. These may be used individually or in combination of two or more. Furthermore, it is preferable that the perovskite layer has a layered perovskite structure in which layers made of metal halides and layers in which organic cation molecules are arranged are alternately stacked.

[0037] The perovskite layer may contain a sensitizing dye. As for the sensitizing dye, there are no particular restrictions as long as it is a compound that is photoexcited by the excitation light used, and it can be appropriately selected according to the purpose. Examples of sensitizing dyes include metal complex compounds, coumarin compounds, polyene compounds, indoline compounds, thiophene compounds, cyanine dyes, merocyanine dyes, 9-arylxanthene compounds, triarylmethane compounds, phthalocyanine compounds, and porphyrin compounds. Among these, metal complex compounds, indoline compounds, thiophene compounds, and porphyrin compounds are preferred.

[0038] The average thickness of the perovskite layer is preferably 50 nm to 800 nm, more preferably 100 nm to 600 nm, and even more preferably 200 nm to 500 nm. If the average thickness of the perovskite layer is 50 nm or more, there will be no insufficient carrier generation due to insufficient light absorption by the perovskite layer, and if it is 800 nm or less, the transport efficiency of carriers generated by light absorption will not decrease further.

[0039] Methods for forming a perovskite layer include, for example, applying a solution in which metal halides, alkylamine halides, etc. are dissolved or dispersed, and then drying by heater heating or gas blowing. Furthermore, methods for forming the perovskite layer include, for example, a two-step precipitation method in which a solution containing dissolved or dispersed metal halides is applied, dried, and then immersed in a solution containing dissolved alkylamine halides to form the perovskite compound. Furthermore, methods for forming a perovskite layer include, for example, applying a solution in which metal halides and alkylamine halides are dissolved or dispersed, while adding a poor solvent (a solvent with low solubility) for the perovskite compound to precipitate crystals. In addition, methods for forming the perovskite layer include, for example, depositing metal halides in a gas filled with methylamine or the like. Among these methods, the method of precipitating crystals by adding a poor solvent for the perovskite compound while applying a solution in which metal halides and alkyl halides are dissolved or dispersed is preferred, as is the method of drying by gas blowing after applying a solution in which metal halides, alkyl halides, etc. are dissolved or dispersed.

[0040] Methods for applying the solution include, for example, immersion, spin coating, spraying, dipping, roller coating, air knife coating, and inkjet coating. Methods for forming a perovskite layer include, for example, mixing a perovskite compound with a sensitizing dye, or forming a perovskite layer and then adsorbing the sensitizing dye.

[0041] <<Passive layer>> In this embodiment, the photoelectric conversion element may have a passivation layer between the perovskite layer and the hole transport layer, which will be described later. Providing a passivation layer improves the stability of the photoelectric conversion element.

[0042] The passivation layer preferably contains a compound represented by the following general formula (2). AX...General formula (2) However, in general formula (2), A represents a monovalent cation and X represents a monovalent anion. The passivation layer is expected to control the properties of the interface by containing the compound represented by general formula (2). Furthermore, it is preferable that the compound represented by general formula (2) is a different salt from the salts that constitute the perovskite layer. Examples of A in general formula (2) include organic cations such as ammonium cation compounds, pyridinium cation compounds, imidazolinium cation compounds, pyrrolidinium cation compounds, and phosphonium cation compounds. Examples of ammonium cation compounds include monoalkylammonium cations, dialkylammonium cations, trialkylammonium cations, tetraalkylammonium cations, trialkylarylammonium cations, dialkyldiarylammonium cations, triarylmethylammonium cations, and phenethylammonium cations. Examples of pyridinium cation compounds include triarylbenzylpyridinium cations, N-alkylpyridinium cations, and N-benzylpyridinium cations. Examples of imidazolinium cation compounds include N-methyl-2-imidazolinium cation and Nn-propyl-2-methylimidazolinium cation. Examples of pyrrolidinium cation compounds include 1-ethyl-1-methylpyrrolidinium cation and 1-n-hexyl-1-methylpyrrolidinium cation. Examples of phosphonium cations include triisobutylmethylphosphonium cation and tetra-n-hexyldodecylphosphonium cation. These organic cations may have substituents. They may be used individually or in combination of two or more.

[0043] Examples of X in general formula (2) include halogen anions such as fluorine anions, chloride anions, bromine anions, and iodine anions.

[0044] Among these, it is preferable that A in general formula (2) is a cation compound containing nitrogen and X is a halogen anion. Specifically, in general formula (2), A is more preferably a monoalkylammonium cation, a dialkylammonium cation, a trialkylammonium cation, a tetraalkylammonium cation, or a phenethylammonium cation, and X is more preferably a bromine anion or an iodine anion. More specifically, the compound represented by general formula (2) is preferably a hydroiodide 5-aminopentanoic acid salt in which A is a monoalkylammonium cation and X is an iodine anion.

[0045] The average thickness of the passivation layer is preferably 0.5 nm to 100 nm, and more preferably 1 nm to 50 nm.

[0046] One method for forming a passivation layer is to apply a solution containing the compound represented by general formula (2) onto a perovskite layer, dry it, and then form a hole transport layer on top of it. Examples of the solution include aqueous solutions and alcoholic solutions. Methods for applying the solution include, for example, immersion, air knife, dip, spray, wire bar, spin coat, roller coat, blade coat, gravure coat, and inkjet.

[0047] The passivation layer may be adsorbed as a single molecule. The passivation layer does not need to be uniformly distributed; for example, it may be in the form of non-continuous islands, existing locally in multiple regions. Furthermore, if the photoelectric conversion layer is a perovskite layer, the passivation layer may be distributed within the perovskite layer or hole transport layer by reacting a compound represented by general formula (2) with a perovskite compound or a hole transport material. In other words, there should be a region where the compound represented by general formula (2) exists between the perovskite layer where the compound represented by general formula (2) does not exist and the hole transport layer where the compound represented by general formula (2) does not exist.

[0048] <<Hall transport layer>> A hole transport layer is a layer that transports holes (positive ions) generated in the perovskite layer to a second electrode, which will be described later. For this reason, it is preferable that the hole transport layer be placed adjacent to the perovskite layer. When the electron transport layer is adjacent to the perovskite layer, it is preferable that the layers be stacked in the order of hole transport layer, perovskite layer, and electron transport layer. Furthermore, when a passivation layer is present, it is preferable that the hole transport layer be placed adjacent to the passivation layer.

[0049] The hole transport layer comprises a solid hole transport material, which may further comprise other solid hole transport materials, and optionally contains other materials such as dopant materials. There are no particular restrictions on solid hole transport materials (hereinafter sometimes simply referred to as "hole transport materials") as long as they are materials that have the property of transporting holes, and they can be appropriately selected according to the purpose, for example, organic compounds. Examples of organic compounds include polythiophene compounds, polyphenylene vinylene compounds, polyfluorene compounds, polyphenylene compounds, polyarylamine compounds, and polythiodiazole compounds. Examples of polythiophene compounds include poly(3-hexylthiophene-2,5-diyl) (hereinafter referred to as "P3HT"), poly(3-n-octyloxythiophene), poly(9,9'-dioctylfluoreneco-bithiophene), poly(3,3'''-didodecyl-quarterthiophene), poly(3,6-dioctylthieno[3,2-b]thiophene), and poly(2,5-bis(3-decylthiophene-2- 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), or poly(3,6-dioctylthiophene[3,2-b]thiophene-co-bithiophene). Examples of 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], or poly[(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene)-co-(4,4'-biphenylene vinylene)]. Examples of 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)], or poly[(9,9-dioctyl-2,7-diyl)-co-(1,4-(2,5-dihexyloxy)benzene)]. Examples of polyphenylene compounds include poly[2,5-dioctyloxy-1,4-phenylene] and poly[2,5-di(2-ethylhexyloxy-1,4-phenylene]. Examples of polyarylamine compounds include poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] (hereinafter referred to as "PolyTPD"), 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)], and poly[(N,N'-bis(4-octyloxyphenyl) Examples include poly[(nyl)benzidine-N,N'-(1,4-diphenylene)], 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], or poly[4-(2-ethylhexyloxy)phenylimino-1,4-biphenylene]. Examples of polythiadiazole compounds include poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo(2,1',3)thiadiazole)] or poly(3,4-didecylthiophene-co-(1,4-benzo(2,1',3)thiadiazole)). Among these, polythiophene compounds and polyarylamine compounds are preferred when considering carrier mobility and ionization potential.

[0050] Polymer materials may also preferably include compounds having the structural unit of the following general formula (3).

[0051] [ka] Ar in general formula (3) 1is an aromatic hydrocarbon group and represents, for example, an aryl group. Examples of the aryl group include a phenyl group, a 1-naphthyl group, a 9-anthracenyl group, etc. The aryl group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an aryl group, etc. Ar in General Formula (3) 2 and Ar 3 each independently represent a divalent group of a monocyclic, non-condensed polycyclic, or condensed polycyclic aromatic hydrocarbon group, and represent, for example, an arylene group, a divalent heterocyclic group, etc. Examples of the arylene group include 1,4-phenylene, 1,1'-biphenylene, 9,9'-di-n-hexylfluorene, etc. Examples of the divalent heterocyclic group include 2,5-thiophene, etc. The arylene group and the divalent heterocyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an aryl group, etc. R in General Formula (3) 1 and R 2 each independently represent a hydrogen atom, an alkyl group, an aryl group, etc. Examples of the alkyl group include a methyl group, an ethyl group, etc. Examples of the aryl group include a phenyl group, a 2-naphthyl group, etc. The alkyl group and the aryl group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an aryl group, etc. Note that n in General Formula (3) represents a natural number of 2 or more.

[0052] The compound having the structural unit of General Formula (3) is preferably a compound having the structural unit of General Formula (4). By doing so, the effect of reducing the resistivity of the hole transport layer can be obtained.

[0053]

Chemical Formula

[0054] The weight-average molecular weight of compounds having structural units of general formulas (3) and (4) is preferably between 20,000 and 150,000. The weight-average molecular weight of a compound can be measured by gel permeation chromatography (GPC).

[0055] Examples of compounds having the structural unit of general formula (4) include (A-1) to (A-22) listed below. However, compounds having the structural unit of general formula (4) are not limited to these.

[0056] [ka] [ka] [ka]

[0057] Other solid hole transport materials may include low-molecular-weight hole transport materials alone or mixtures of low-molecular-weight and high-molecular-weight materials. There are no particular restrictions on the low molecular weight hole transport materials, and examples include oxadiazole compounds, triphenylmethane compounds, pyrazoline compounds, hydrazone compounds, tetraarylbenzidine compounds, stilbene compounds, spirobifluorene compounds, and thiophene oligomers. Among these, spirobifluorene compounds are preferred. Of the spirobifluorene compounds, 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (hereinafter referred to as "Spiro-OMeTAD") is preferred.

[0058] The average thickness of the hole transport layer is preferably 10 nm to 1000 nm, and more preferably 20 nm to 100 nm.

[0059] The hole transport layer can be formed directly on the perovskite layer. A wet film formation method is preferred for forming the hole transport layer, and an inkjet method is more preferred. Using an inkjet method allows for the formation of the hole transport layer in desired areas. Furthermore, multiple inkjet heads can be used to simultaneously coat multiple solutions.

[0060] One method for identifying hole transport materials is to use a Fourier transform infrared spectrometer (FT-IR) (e.g., instrument name: IRTracer-100, manufactured by Shimadzu Corporation) to identify the hole transport material based on its constituent components. In the hole transport layer, the constituent components of the polymer of the hole transport material exist as residual monomers; therefore, by identifying the residual hole transport material, the constituent components of the hole transport material can be identified.

[0061] <<<Dopant Materials>>> Other materials included in the hole transport layer include dopant materials. There are no particular restrictions on the dopant material, and it can be appropriately selected depending on the purpose, for example, an oxidizing agent.

[0062] There are no particular restrictions on the dopant material, and it can be appropriately selected according to the purpose. Examples include iodine; metallic iodides such as lithium iodide, sodium iodide, potassium iodide, cesium iodide, calcium iodide, copper iodide, iron iodide, or silver iodide; quaternary ammonium salts such as tetraalkylammonium iodide or pyridinium iodide; metallic bromides such as lithium bromide, sodium bromide, potassium bromide, cesium bromide, or calcium bromide; brominated salts of quaternary ammonium compounds such as tetraalkylammonium bromide or pyridinium bromide; metallic chlorides such as copper chloride or silver chloride; copper acetate, silver acetate Alternatively, examples include metal acetate salts such as palladium acetate; metal sulfates such as copper sulfate or zinc sulfate; metal complexes such as cobalt complexes, ferrocyanate-ferricyanate or ferrocene-ferricinium ions; sulfur compounds such as sodium polysulfide or alkylthiol-alkyl disulfide; basic compounds such as viologen dyes, hydroquinone, pyridine, 4-t-butylpyridine (tBP) or benzimidazole; and lithium sulfonyl salts such as lithium bis(trifluoromethane)sulfonylimide (LiTFSI) and lithium bisfluorosulfonylimide (LiFSI). Furthermore, examples of dopant materials include photoacid generators having photosensitizing moieties such as sulfonium salts and iodonium salts shown in D-01 to D-19, which can be suitably used as dopant materials for compounds represented by general formula (4).

[0063] [ka] [ka]

[0064] Other dopant materials are not particularly limited and can be selected as appropriate depending on the purpose. Examples include tris(4-bromophenyl)ammonium yl hexachloroantimonate, silver hexafluoroantimonate, nitrosonium tetrafluorolate, and silver nitrate. It is not necessary for the entire hole transport material to be oxidized by the dopant material; partial oxidation is sufficient. Furthermore, the dopant material may or may not be removed from the system after the reaction.

[0065] By including a dopant material in the hole transport layer, it becomes possible to convert some or all of the hole transport material into radical cations, thereby improving conductivity and enhancing the durability and stability of the output characteristics. There are no particular restrictions on the mass ratio of hole transport material to dopant material (hole transport material / dopant material) in the hole transport layer, and it can be appropriately selected according to the purpose. From the viewpoint of hole movement, a ratio of 1 to 40 is preferred, and a ratio of 10 to 40 is more preferred.

[0066] Dopant materials can be identified by using methods such as time-of-flight secondary ion mass spectrometry (TOF-SIMS), liquid chromatography-mass spectrometry (LC-MS), and gas chromatography-mass spectrometry (GC-MS).

[0067] Regarding the concentration of the dopant material in the hole transport layer, a concentration distribution or concentration gradient may be provided. For example, the concentration of the dopant material may be varied in the stacking direction of the laminate, as shown in (1) to (4) below. Varying the concentration of the dopant material in the stacking direction of the laminate can also be described as varying the concentration of the dopant material in the thickness direction of the hole transport layer. (1) A concentration gradient is provided such that the concentration is higher on the photoelectric conversion layer side and lower on the second electrode side. (2) A concentration gradient is provided such that the concentration on the second electrode side is high and the concentration on the photoelectric conversion layer side is low. (3) A concentration gradient is provided such that the concentration is lower on the photoelectric conversion layer side, higher in the central part of the hole transport layer in the thickness direction, and lower on the second electrode side. (4) A concentration gradient is provided such that the concentration is higher on the photoelectric conversion layer side, lower in the central part of the hole transport layer in the thickness direction, and higher on the second electrode side.

[0068] By creating a concentration gradient in the dopant material within the hole transport layer, unintended diffusion of the dopant into adjacent layers can be prevented, and the resistivity of the hole transport layer can be reduced. As a result, conductivity is improved, and the durability and stability of the output characteristics can be enhanced.

[0069] Methods for creating a concentration gradient in the dopant material within the hole transport layer include, for example, applying the hole transport material containing dopant material of different concentrations in multiple applications. Specifically, when forming a hole transport layer by alternately applying the hole transport material and dopant material, a method can be used to create a dopant concentration gradient in the thickness direction of the hole transport layer by changing the amount of dopant material applied with each application. Methods for adjusting the amount of dopant material applied include using two or more inkjet heads, one for the hole transport material-containing solution and the other for the dopant material-containing solution, to apply two or more liquids in a pattern. Specifically, these methods include adjusting the ejection amount by changing the drive frequency of the inkjet head; adjusting the ejection amount by changing the number of nozzles of the ejecting inkjet head; and preparing dopant material-containing solutions with different concentrations of dopant material and corresponding inkjet heads, respectively, and adjusting the concentration and ejection amount of the ejected dopant material.

[0070] <Second electrode> The second electrode can be formed on the laminate. The second electrode can be the same as the first electrode. In the case of a forward-type photoelectric element, the laminate has an electron transport layer, a photoelectric conversion layer, and a hole transport layer in that order on the first electrode, and the second electrode can be provided on the hole transport layer. In the case of an inverted-type photoelectric element, the laminate has a hole transport layer, a photoelectric conversion layer, and an electron transport layer in that order on the first electrode, and the second electrode can be provided on the electron transport layer. The second electrode includes a laminated portion provided on the laminate, as well as a side portion that covers a part of the side surface of the laminate. The side portion of the second electrode is provided so as to cover the laminate along the lamination direction on a part of the outer circumference of the laminate. The side portion of the second electrode included in the photoelectric conversion module is provided so as to face the adjacent photoelectric conversion element with a gap between them. Specifically, as shown in the photoelectric conversion module of Figure 2 described later, it is preferable that the side portion 7a of the second electrode in the photoelectric conversion element 10A is provided so as to cover one side surface of the laminate provided by reference numerals 2 to 6, and faces the high-resistance layer 8 provided on the adjacent photoelectric conversion element 10B with a gap G between them. The presence of a side portion in the second electrode makes it possible to electrically connect the first electrode and the second electrode of adjacent photoelectric conversion elements.

[0071] Examples of materials for the second electrode include metals, carbon compounds, conductive metal oxides, and conductive polymers. Examples of metals include platinum, gold, silver, copper, and aluminum. Examples of carbon compounds include graphite, fullerenes, carbon nanotubes, and graphene. Examples of conductive metal oxides include ITO, FTO, and ATO. Examples of conductive polymers include polythiophene and polyaniline. These can be used individually or in combination of two or more.

[0072] In the case of a forward-type photoelectric conversion element, the second electrode can be formed on the hole transport layer by appropriate methods such as coating, lamination, vapor deposition, CVD, or bonding. It is preferable that at least one of the first electrode and the second electrode is substantially transparent, and it is more preferable that the first electrode side is transparent. The transparency of the first electrode side allows incident light to be introduced from the first electrode side.

[0073] <High resistance layer> The high-resistance layer is provided between adjacent photoelectric conversion elements. When the adjacent photoelectric conversion elements are the first photoelectric conversion element and the second photoelectric conversion element, the high-resistance layer is provided between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element.

[0074] The high-resistance layer preferably covers at least a portion of the side surface of the hole transport layer. The side surface of the hole transport layer refers to the outer edge of the hole transport layer along the stacking direction of each layer of the photoelectric conversion element. Preferably, the high-resistance layer is provided so as to cover the side surface of the laminate facing the side surface of the second electrode, thereby suppressing current flow between adjacent photoelectric conversion elements and the second electrode of adjacent photoelectric conversion elements, even when multiple photoelectric conversion elements are electrically connected.

[0075] The high-resistance layer may be provided to cover the entire side surface of the hole transport layer, to cover a portion of the side surface of the laminate, to cover the entire side surface of the laminate, or to cover a portion of the side surfaces of the laminate and the second electrode. By providing the high-resistance layer to cover at least a portion of the side surface of the hole transport layer, short circuits between adjacent photoelectric conversion elements can be suppressed when a photoelectric conversion module is fabricated. Here, covering the entire side surface of the hole transport layer refers to the entire outer edge of the hole transport layer along the stacking direction of each layer of the photoelectric conversion elements. From the viewpoint of suppressing short circuits with adjacent photoelectric conversion elements, the high-resistance layer is preferably provided so as to cover the entire side surface of the hole transport layer, and more preferably so as to cover the entire side surface of the laminate.

[0076] When fabricating the photoelectric conversion module, the high-resistance layer is preferably positioned to face the side portion of the second electrode of an adjacent photoelectric conversion element. As a result, short circuits between adjacent photoelectric conversion elements can be suppressed.

[0077] The high-resistance layer has no particular restrictions on its shape or size as long as it can suppress short circuits between adjacent photoelectric conversion elements when fabricating a photoelectric conversion module, and can be appropriately selected according to the purpose.

[0078] As long as the high-resistivity layer has a higher resistivity than the hole transport layer, there are no particular restrictions, and it can be appropriately selected according to the purpose. Similarly, in the case of an inverse-type photoelectric conversion element, the effects of the present invention can be obtained if the high-resistivity layer has a higher resistivity than the hole transport layer. The high-resistivity layer's resistivity is higher than that of the hole transport layer, which suppresses short circuits between adjacent photoelectric conversion elements. By suppressing short circuits between adjacent photoelectric conversion elements, power generation efficiency can be maintained even after prolonged exposure to high-intensity light.

[0079] The resistivity of the high-resistivity layer is defined as the difference between the resistivity of the high-resistivity layer (hereinafter referred to as "Ra") and the resistivity of the hole transport layer (hereinafter referred to as "Rb") (Ra-Rb), which is 1.0 × 10⁻⁶. 8 Preferably Ωcm or more, 1.5 × 10 8 Ωcm or more 20.0 × 10 8 Ωcm or less is more preferable, and 2.5 × 10 8 Ωcm or greater: 10.0 × 10 8 A value of Ωcm or less is even more preferable.

[0080] Resistivity can be measured using a scanning spread resistance microscope (SSRM). One method for measuring the resistivity of a high-resistivity layer is to cut the photoelectric conversion element in a direction perpendicular to the stacking direction and measure the cross-section of the high-resistivity layer with an SSRM.

[0081] Examples of materials for the high-resistance layer include insulating materials and hole transport materials. Examples of insulating materials include ceramics and synthetic resins. Examples of ceramics include aluminum oxide, zirconium oxide, aluminum nitride, silicon nitride, forsterite, steatite, sialon, and mica. Examples of synthetic resins include polyethylene, polyvinyl chloride, polystyrene, polyester, phenolic resin, melamine resin, epoxy resin, and silicone resin. As the hole transport material, the compounds listed in the section on hole transport materials can be used as appropriate. When using a hole transport material as the material for the high-resistance layer, the same material as the hole transport material applied to the hole transport layer may be applied.

[0082] Preferably, the hole transport layer contains a hole transport material and a dopant material, while the high-resistance layer contains a hole transport material but does not contain a dopant material. By not containing a dopant material in the high-resistance layer, the resistivity can be increased compared to a hole transport layer containing a dopant material. Here, the hole transport material contained in the hole transport layer and the hole transport material contained in the high-resistance layer may be the same or different, but from the viewpoint of facilitating manufacturing, it is preferable that they be the same.

[0083] The high-resistance layer is preferably provided in a range of 200 μm or less from the edge of the laminate, starting from the edge. The width of the high-resistance layer is preferably 20 μm or more and 200 μm or less. Here, the width of the high-resistance layer refers to the length of the high-resistance layer in a direction perpendicular to the stacking direction in which each layer of the photoelectric conversion element is stacked.

[0084] <Other components> <<Second circuit board>> The photoelectric conversion element and photoelectric conversion module in this embodiment may have a second substrate. There are no particular restrictions on the second substrate; it can be appropriately selected according to the purpose, and the same type as the first substrate can be used. The second substrate is positioned opposite the first substrate, sandwiching the laminate.

[0085] There are no particular restrictions on the shape, structure, or size of the second substrate, and it can be appropriately selected according to the purpose. There are no particular restrictions on the material of the second substrate, and it can be appropriately selected according to the purpose; for example, the same material as the first substrate can be used.

[0086] Examples of the second substrate include glass, plastic film, and ceramic. The joint between the second substrate and the sealing member may have an uneven surface to improve adhesion. Methods for forming uneven surfaces include, for example, sandblasting, water blasting, abrasive paper, chemical etching, and laser processing. To improve the adhesion between the second substrate and the sealing member described later, for example, organic matter on the surface may be removed, or hydrophilicity may be improved. Examples of methods for removing organic matter from the surface of the second substrate include UV ozone cleaning and oxygen plasma treatment.

[0087] <<Sealing member>> In this embodiment, it is preferable that the photoelectric conversion element has a sealing member that shields the photoelectric conversion layer from the external environment of the photoelectric conversion element. The material of the sealing component is not particularly limited as long as it can reduce the intrusion of excessive moisture, oxygen, etc., from the external environment into the sealed interior, and can be appropriately selected according to the purpose. In addition, the sealing component has the effect of preventing mechanical damage caused by external pressure.

[0088] The sealing methods include, for example, "frame sealing," in which a sealing member is provided around the periphery of the power generation region, which is composed of the photoelectric conversion layer of the photoelectric conversion element, and bonded to a second substrate, and "surface sealing," in which a sealing member is provided over the entire power generation region and bonded to a second substrate. "Frame sealing" creates a hollow space inside the seal, allowing for proper adjustment of moisture and oxygen levels within the seal. Furthermore, since the second electrode is not in contact with the sealing material, the effects of electrode detachment can be reduced. "Surface sealing" is excellent at preventing the intrusion of excessive water and oxygen from the outside, and because of the large bonding area with the sealing material, it has high sealing strength and is particularly suitable when a flexible substrate is used as the first substrate.

[0089] There are no particular restrictions on the material of the sealing member, and it can be appropriately selected according to the purpose. Examples include curing resins and low-melting-point glass resins. As for the curing resin, there are no particular restrictions as long as it is a resin that hardens with light or heat, and it can be appropriately selected according to the purpose. Examples include cured acrylic resin and cured epoxy resin. Low-melting-point glass resins are sealed by first applying the resin and then firing it to decompose the resin components, followed by melting it with an infrared laser or the like, and then bonding it tightly 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 UV-curing resins, making it effective for increasing the durability of photoelectric conversion elements. Generally, these are commercially available as glass frit or glass paste, and can be effectively used.

[0090] Methods for forming sealing members include, for example, 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.

[0091] An example of a photoelectric conversion element of this embodiment 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 components of the following configuration that are not described in this embodiment are also included in the scope of the present invention.

[0092] Figure 1 is a schematic diagram of a photoelectric conversion element according to the first embodiment. Figure 1 shows an example of a forward-type photoelectric conversion element. The photoelectric conversion element 10 in Figure 1 comprises a first electrode 2, a laminate comprising an electron transport layer 3, a perovskite layer 4 which is a photoelectric conversion layer, a passivation layer 5, and a hole transport layer 6 in that order, a second electrode 7 provided opposite the first electrode 2 via the laminate, and a high-resistance layer 8. The first electrode 2 is in contact with the electron transport layer 3. The electron transport layer 3 is in contact with the perovskite layer 4. The perovskite layer 4 is in contact with the passivation layer 5. The passivation layer 5 is in contact with the hole transport layer 6. The hole transport layer 6 is in contact with the second electrode 7. The second electrode 7 has a side portion 7a that covers a part of the side surface of the laminate. The side portion 7a communicates with the second electrode 7 in contact with the hole transport layer 6 and extends to the first substrate 1, thereby enabling electrical connection with the first electrode 2 of an adjacent photoelectric conversion element. The high-resistance layer 8 is provided to cover the electron transport layer 3, the perovskite layer 4, the passivation layer 5, and a part of the side surface of the hole transport layer 6. The high-resistance layer 8 may also be provided to cover the side surface of the second electrode 7.

[0093] In the first embodiment, the high-resistance layer 8 is provided so as to cover the side surface of the laminate facing the side portion 7a of the second electrode 7 relative to the hole transport layer 6. By positioning the high-resistance layer 8 on the side surface of the laminate facing the side portion 7a of the second electrode 7 relative to the hole transport layer 6, short circuits between adjacent photoelectric conversion elements can be suppressed when a photoelectric conversion module is fabricated.

[0094] The high-resistivity layer 8 has a higher resistivity than the hole transport layer 6 of the adjacent photoelectric conversion element. In other words, the hole mobility of the high-resistivity layer 8 is lower than that of the hole transport layer 6. Because the resistivity of the high-resistivity layer 8 is higher than that of the hole transport layer 6, short circuits between adjacent photoelectric conversion elements can be suppressed.

[0095] Figure 2 is a schematic diagram showing an example of a photoelectric conversion module corresponding to the first embodiment. The photoelectric conversion module 100 shown in Figure 2 comprises a first substrate 1 and photoelectric conversion elements 10A to 10C. The photoelectric conversion module 100 has multiple photoelectric conversion elements of the first embodiment electrically connected in series. The photoelectric conversion module 100 has a gap G between two adjacent photoelectric conversion elements. The photoelectric conversion module 100 is provided such that the side portion 7a of the second electrode 7 and the high-resistance layer 8 face each other across the gap G. The side portion 7a communicates with the second electrode 7 which is in contact with the hole transport layer 6, extends to the first substrate 1, and is electrically connected to the first electrode 2 of the adjacent photoelectric conversion element. The photoelectric conversion module 100 shown in Figure 2 has three photoelectric conversion elements (10A to 10C), but the number of photoelectric conversion elements is not limited to three and can be appropriately selected according to the purpose. The photoelectric conversion elements 10A, 10B, and 10C are sometimes collectively referred to as the photoelectric conversion element 10.

[0096] The first electrode 2 of photoelectric conversion element 10B is electrically connected to the second electrode 7 of the adjacent photoelectric conversion element 10A. The first electrode 2 of photoelectric conversion element 10C is electrically connected to the second electrode 7 of the adjacent photoelectric conversion element 10B. The first electrode 2 and the second electrode 7 of photoelectric conversion element 10 have a path that conducts to the electrode extraction terminal.

[0097] The photoelectric conversion element 10B can suppress short circuits with adjacent photoelectric conversion elements 10A by having a high-resistance layer 8. The photoelectric conversion element 10C can suppress short circuits with adjacent photoelectric conversion elements 10B by having a high-resistance layer 8.

[0098] Figure 3 is a schematic diagram showing an example of a photoelectric conversion module corresponding to the first embodiment. The photoelectric conversion module 100 shown in Figure 3 comprises a first substrate 1, a plurality of photoelectric conversion elements 10, a second substrate 101, and a sealing member 102. The second substrate 101 is positioned opposite the first substrate 1, sandwiching the photoelectric conversion elements 10. The sealing member 102 is positioned between the first substrate 1 and the second substrate 101.

[0099] Figure 4 is a schematic diagram of the photoelectric conversion element of the second embodiment. Figure 4 is a diagram showing an example of a forward-type photoelectric conversion element. In the second embodiment, explanations that overlap with the description of the first embodiment will be omitted as appropriate.

[0100] The photoelectric conversion element 20 shown in Figure 4 differs from the first embodiment in that a high-resistance layer 8 is provided so as to cover the entire side surface of a laminate comprising a first electrode 2, an electron transport layer 3, a perovskite layer 4, a passivation layer 5, and a hole transport layer 6 in that order. The high-resistance layer 8 is provided between the laminate and the side portion 7a of the second electrode 7. By providing the high-resistance layer 8 so as to cover the entire side surface of the laminate, short circuits between adjacent photoelectric conversion elements can be further suppressed.

[0101] Figure 5 is a schematic diagram showing an example of a photoelectric conversion module corresponding to the second embodiment. Figure 5 shows a plurality of photoelectric conversion elements of the second embodiment electrically connected in series. Figure 6 is a top view of the photoelectric conversion module shown in Figure 5. Figure 7 is a top view of the photoelectric conversion module shown in Figure 5, cut along the dotted line A-A'. The photoelectric conversion module 200 shown in Figures 5 to 7 comprises a first substrate 1 and photoelectric conversion elements 20A to 20E. The photoelectric conversion module 200 shown in Figures 5 to 7 has five photoelectric conversion elements (20A to 20E), but the number of photoelectric conversion elements is not limited to five and can be appropriately selected according to the purpose. The photoelectric conversion elements 20A to 20E are sometimes collectively referred to as the photoelectric conversion element 20.

[0102] The high-resistance layer 8 is provided so as to be in contact with the entire side surface of the electron transport layer 3, the perovskite layer 4, the passivation layer 5, and the hole transport layer 6. This helps to suppress short circuits with adjacent elements.

[0103] Figure 8 is a schematic diagram of the photoelectric conversion element of the third embodiment. Figure 8 is a diagram showing an example of an inverse type photoelectric conversion element. In the third embodiment, explanations that overlap with the descriptions of the first and second embodiments will be omitted as appropriate. The inverse photoelectric conversion element 30 includes a first electrode 2, a laminate comprising a hole transport layer 6, a perovskite layer 4, a passivation layer 5, and an electron transport layer 3 in that order, a second electrode 7 provided opposite the first electrode 2 via the laminate, and a high-resistance layer 8. The second electrode 7 has a side portion 7a that covers a part of the side surface of the laminate. The high-resistance layer 8 is provided to cover a part of the side surface of the laminate. The high-resistance layer 8 may also be provided to cover the side surface of the second electrode 7.

[0104] The high-resistivity layer 8 of the inverted photoelectric conversion element 30 has a higher resistivity than the hole transport layer 6. Because the resistivity of the high-resistivity layer 8 is higher than that of the hole transport layer 6, short circuits between adjacent photoelectric conversion elements can be suppressed when a photoelectric conversion module is fabricated. The high-resistance layer 8 of the inverse-type photoelectric conversion element 30 contains an insulating material.

[0105] Figure 9 is a schematic diagram of the photoelectric conversion element of the fourth embodiment. Figure 9 is a diagram showing an example of a forward-type photoelectric conversion element. In the fourth embodiment, explanations that overlap with the descriptions of the first to third embodiments will be omitted as appropriate.

[0106] The photoelectric conversion element 40 shown in Figure 9 comprises a first electrode 2, a laminate comprising an electron transport layer 3, a perovskite layer 4, a passivation layer 5, and a hole transport layer 6 in that order, a second electrode 7 provided opposite the first electrode 2 via the laminate, and a high-resistance layer 8. The second electrode 7 has a side portion 7a that covers a part of the side surface of the laminate. The high-resistance layer 8 differs from the first embodiment in that it is provided so as to cover the side portion 7a of the second electrode. That is, the high-resistance layer 8 is provided in contact with the side of the side portion 7a of the second electrode that is opposite to the surface where the laminate and the second electrode are in contact.

[0107] Figure 10 is a schematic diagram showing an example of a photoelectric conversion module corresponding to the fourth embodiment. Figure 10 shows a plurality of photoelectric conversion elements of the fourth embodiment electrically connected in series. The photoelectric conversion module 400 shown in Figure 10 comprises a first substrate 1 and photoelectric conversion elements 40A to 40C. At least one photoelectric conversion element 40A has a high-resistance layer 8 that covers at least a portion (side portion 7a) of the side surface of the second electrode 7 facing the side surface of the laminate of the adjacent photoelectric conversion element 40B. By providing the high-resistance layer 8 to cover a portion (side portion 7a) of the side surface of the second electrode 7 facing the side surface of the laminate of the adjacent photoelectric conversion element, short circuits between adjacent photoelectric conversion elements can be further suppressed. Here, having a high-resistance layer between the second electrode 7 of the first photoelectric conversion element 40A and the laminate of the second photoelectric conversion element 40B means that there is a high-resistance layer 8 between the side portion 7a of the second electrode 7 of the first photoelectric conversion element 40A and the surface of the laminate of the second photoelectric conversion element 40B that is closer to the first photoelectric conversion element 40A.

[0108] In the fourth embodiment, the high-resistance layer 8 is preferably provided in contact with either the side surface 7a of the second electrode of the first photoelectric conversion element 40A or the side surface of the laminate of the second photoelectric conversion element 40B. This configuration allows for easy formation of the high-resistance layer. Furthermore, in the photoelectric conversion element of the fourth embodiment, it is preferable that the space between the side surface 7a of the second electrode of the first photoelectric conversion element 40A and the surface of the second photoelectric conversion element 40B on the side closer to the first photoelectric conversion element 40A is not filled with the high-resistance layer 8. That is, it is preferable that a gap G exists between the side surface 7a of the second electrode of the first photoelectric conversion element and the surface of the second photoelectric conversion element on the side closer to the first photoelectric conversion element 40A. The presence of the gap G further suppresses short circuits between the photoelectric conversion elements.

[0109] In the fourth embodiment, the high-resistance layer 8 preferably has an insulating material. Having an insulating material in the high-resistance layer 8 enhances the effect of suppressing short circuits between photoelectric conversion elements.

[0110] In the fourth embodiment shown in Figure 10, the high-resistance layer 8 can be formed by first forming the second electrode 7 and the side portion 7a, and then applying a material having an insulating properties to the position in contact with the second electrode 7 and the side portion 7a.

[0111] By having a high-resistance layer 8 between the second electrode 7 of the first photoelectric conversion element 40A and the laminate of the second photoelectric conversion element 40B, it is possible to suppress short circuits that may occur between the second electrode 7 of the first photoelectric conversion element 40A and the laminate of the second photoelectric conversion element.

[0112] <Application> The photoelectric conversion element and / or photoelectric conversion module of this embodiment functions as a self-contained power source. Using the photoelectric conversion module of this embodiment, it is possible to generate electricity when light is shone upon it, making it possible to operate electronic devices even in locations without power supply equipment, to carry them around, and to operate electronic devices without replacing batteries in locations where battery replacement is difficult. Furthermore, because the photoelectric conversion module of this embodiment is lightweight and thin, it offers high flexibility in installation and significant advantages for wearing or carrying around.

[0113] The photoelectric conversion element and / or photoelectric conversion element module of this embodiment can be applied to a power supply device by combining it with a circuit board or the like that controls the generated current. Examples of electronic devices that utilize this power supply device include electronic desktop calculators, wristwatches, mobile phones, electronic organizers, and electronic paper. Furthermore, by combining it with an auxiliary power supply or secondary battery to extend the continuous use time of rechargeable or battery-powered electrical appliances, the power supply device having the photoelectric conversion element of this embodiment can be used as a power source that can be used even at night. Moreover, it can be used as a self-contained power source that does not require battery replacement or power wiring for IoT devices, artificial satellites, and the like.

[0114] (electronic equipment) The photoelectric conversion element and / or photoelectric conversion module of this embodiment can be used in electronic devices. The electronic device of this embodiment comprises the photoelectric conversion element and / or photoelectric conversion module of this embodiment, a device that operates using the power generated by the photoelectric conversion performed by the photoelectric conversion module, and further comprises other devices as necessary.

[0115] Figure 9 is a schematic diagram showing an example of an electronic device that combines the photoelectric conversion module of this embodiment with a device that operates using the power generated by its photoelectric conversion. In this device, when light is shone on the photoelectric conversion element, electricity is generated and power can be extracted. The electronic device's circuitry can then operate using that power.

[0116] The electronic device shown in Figure 9 comprises a photoelectric conversion module 100, a power supply IC (Integrated Circuit) 202, a power storage device 203, and an equipment circuit 209. The power supply IC 202 and the power storage device 203 do not necessarily have to be provided in the electronic device. Examples of the power storage device 203 include electric double-layer capacitors, lithium-ion capacitors, and lithium-ion secondary batteries. By providing the power supply IC 202 between the photoelectric conversion module 100 and the equipment circuit 209, the electronic device can supply a stable voltage to the equipment circuit. By providing the power storage device 203 between the power supply IC 202 and the equipment circuit 209, the electronic device can charge the power storage device 203 with excess power from the photoelectric conversion element. This makes it possible to supply power stored in the power storage device 203 to the equipment circuit 209 even when the illumination is too low or when no light hits the photoelectric conversion module 100, allowing for stable operation.

[0117] Thus, electronic devices utilizing the photoelectric conversion element and / or photoelectric conversion module of this embodiment can operate even in environments without a power supply, eliminating the need for battery replacement. Furthermore, electronic devices combining the photoelectric conversion module of this embodiment with an equipment circuit can be stably driven by combining it with a power supply IC and an energy storage device.

[0118] (Power module) The photoelectric conversion element and / or photoelectric conversion module of this embodiment can be used in a power supply module. The power supply module of this embodiment comprises the photoelectric conversion element and / or photoelectric conversion module of this embodiment, a power supply IC, and further comprises other devices as necessary.

[0119] Figure 10 is a schematic diagram showing an example of a power supply module that combines the photoelectric conversion module 100, the power supply IC 202, and the energy storage device 203 of this embodiment. The power supply module shown in Figure 10 comprises the photoelectric conversion module 100, the power supply IC 202, and the energy storage device 203. The energy storage device 203 does not necessarily have to be provided in the power supply module. In the section on power modules, explanations that overlap with those for electronic devices will be omitted as appropriate.

[0120] (building materials) The photoelectric conversion element and / or photoelectric conversion module of this embodiment can be used in building materials. Examples of building materials include building-integrated photovoltaics (BIPV) and building-attached photovoltaics (BAPV). Building-integrated solar cells are building materials in which the functional material that makes up the exterior wall of a building and the solar power generation device are integrated into one unit. Building-mounted solar panels are solar cells that are attached to the exterior walls of buildings to generate solar power. Examples of building-mounted solar panels include film-type panels that can be attached to the exterior walls of buildings.

[0121] Figure 11 is a schematic diagram showing an example of a building material utilizing the photoelectric conversion module of this embodiment. The building material 1000 shown in Figure 11 comprises the photoelectric conversion module 100 of this embodiment and a pair of opposing glass panels 1001. The building material utilizing the photoelectric conversion module of this embodiment may have other components as needed. A pair of opposing glass panels 1001 are arranged so as to sandwich the photoelectric conversion module 100. A space A is provided between the photoelectric conversion module 100 and one of the glass panels 1001. Space A may be filled with an inert gas. Examples of inert gases include nitrogen and argon.

[0122] The building materials of this embodiment may be used for both indoor and outdoor applications. When the building materials of this embodiment are used as window glass, it is preferable that the photoelectric conversion module 100 and the glass 1001 are transparent.

[0123] However, the building materials utilizing the photoelectric conversion module of this embodiment are not limited to those described herein. For example, the number, position, shape, etc. of components not described in this embodiment are also included within the scope of the present invention.

[0124] (Method for manufacturing a photoelectric conversion element, and method for manufacturing a photoelectric conversion module) The method for manufacturing the photoelectric conversion element of this embodiment includes the steps of forming a first electrode, forming a laminate by stacking an electron transport layer, a photoelectric conversion layer, and a hole transport layer, forming a second electrode on the laminate, forming a high-resistance layer that covers at least a portion of the side surface of the hole transport layer or at least a portion of the side surface of the second electrode, and further, if necessary, other steps.

[0125] The method for manufacturing the photoelectric conversion module of this embodiment includes the steps of forming a first photoelectric conversion element and a second photoelectric conversion element on a substrate, each having a first electrode, a laminate, and a second electrode in that order, and forming a high-resistivity layer between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element, the high-resistivity layer having a higher resistivity than the hole transport layer of the second photoelectric conversion element. The laminate comprises an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer. The second electrode of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are electrically connected. The resistivity of the high-resistivity layer is higher than that of the hole transport layer of the second photoelectric conversion element. The photoelectric conversion element and photoelectric conversion module of this embodiment can be suitably manufactured by the manufacturing method of the photoelectric conversion element and photoelectric conversion module of this embodiment.

[0126] <Process for forming the first electrode> The step of forming the first electrode is the step of forming the first electrode on a substrate. The method for forming the first electrode can be appropriately selected from the methods described above for the photoelectric conversion element.

[0127] <Laminate formation process> The laminate formation process involves stacking an electron transport layer, a photoelectric conversion layer, and a hole transport layer to form a laminate. As for the method of forming the electron transport layer, photoelectric conversion layer, and hole transport layer, the matters described above for the photoelectric conversion element can be appropriately selected.

[0128] <Process for forming the second electrode> The step of forming the second electrode is the step of forming the first electrode on the substrate. The method for forming the second electrode can be appropriately selected from the methods described above for the photoelectric conversion element.

[0129] <High resistance layer formation process> The high-resistance layer formation process is a process of forming a high-resistance layer that covers at least a portion of the side surface of the hole transport layer or at least a portion of the side surfaces of the two electrodes. Specifically, examples include a first embodiment (Figures 1-2) in which the high-resistance layer 8 covers the side surface of the laminate facing the side surface portion 7a of the second electrode 7 relative to the hole transport layer 6; a second embodiment (Figures 4-5) in which the high-resistance layer 8 is provided between the laminate and the side surface portion 7a of the second electrode 7; and a fourth embodiment (Figures 9-10) in which the high-resistance layer 8 is provided in contact with the surface of the side surface portion 7a of the second electrode opposite to the surface where the laminate and the second electrode are in contact. Furthermore, it may also be an inverted type photoelectric conversion element and photoelectric conversion module (for example, the third embodiment). When covering at least a portion of the side surface of the hole transport layer, it may be performed simultaneously with or before or after the formation of the hole transport layer.

[0130] A wet dopant method is preferred for applying the dopant material to the hole transport layer and / or high-resistance layer, and an inkjet method is more preferred. By using an inkjet method, the dopant material can be applied to the desired areas. Furthermore, by using multiple inkjet heads, it becomes possible to apply multiple solutions, and the resistivity of the hole transport layer and high-resistance layer in the targeted areas can be arbitrarily changed.

[0131] Methods for forming a hole transport layer and / or high-resistance layer include, for example, applying any of the following combinations to the area where the hole transport layer and / or high-resistance layer is to be formed: (1) a combination of two or more mixed solutions of dopant materials and hole transport materials with different dopant concentrations (hereinafter referred to as "mixed solutions"), (2) a combination of a mixed solution and a solution containing a hole transport material but not a dopant material (hereinafter referred to as "hole transport solution") or a solution containing a dopant material but not a hole transport material (hereinafter referred to as "dopant solution"), or (3) a combination of a hole transport solution and a dopant solution. By using these methods, the application of dopant material to undesirable areas can be avoided, and short circuits between adjacent photoelectric conversion elements can be suppressed. As a method for forming a hole transport layer and / or high-resistance layer, it is preferable to apply any of the following combinations to the area where the hole transport layer and / or high-resistance layer is to be formed: (1) a combination of two mixed solutions with different dopant concentrations, (2) a combination of a hole transport solution or dopant solution and one mixed solution, or (3) a combination of a hole transport solution and a dopant solution. From the viewpoint of resistivity control, the method of applying a dopant solution and a hole transport solution to the area where the hole transport layer and / or high-resistance layer is to be formed is more preferable. Note that dopant concentration refers to the concentration of the dopant material in the dopant solution or mixed solution. In other words, the solution applied to the region where the high-resistance layer is to be formed preferably has a lower dopant concentration than the solution applied to the region where the hole transport layer is to be formed.

[0132] One method for applying two mixed solutions with different dopant concentrations is to apply the mixed solution with a high dopant concentration to the area where the hole transport layer is to be formed, and to apply the mixed solution with a low dopant concentration to the area where the high-resistance layer is to be formed.

[0133] Methods for applying the dopant solution and a mixed solution include applying the mixed solution after applying the dopant solution, applying the dopant solution after applying the mixed solution, and applying the mixed solution and the dopant solution simultaneously from different inkjet heads. It is preferable to apply the dopant solution to the area where the hole transport layer is to be formed, and the mixed solution to the area where the hole transport layer and the high-resistance layer are to be formed. Methods for applying the hole transport solution and a mixed solution include applying the hole transport solution first and then the mixed solution, applying the mixed solution first and then the hole transport solution, and applying the mixed solution and the hole transport solution simultaneously from different inkjet heads. It is preferable to apply the hole transport solution to the area where the hole transport layer and the high-resistance layer are to be formed, and to apply the mixed solution to the area where the hole transport layer is to be formed. That is, the mixed solution is applied to the area on the photoelectric conversion layer where the hole transport layer is to be formed, or applied to the hole transport solution applied on the photoelectric conversion layer. As a result, the hole transport layer contains a dopant material, and the high-resistance layer does not contain a dopant material, so the resistivity of the high-resistance layer is the same as that of the hole transport layer. The ratio can be made higher than the standard. This allows for the provision of a high-resistance layer to cover at least a portion of the sides of the hole transport layer.

[0134] The dopant solution and hole transport solution can be applied by replacing the mixed solution described in the method for applying the hole transport solution and one type of mixed solution with the dopant solution. With this method, the hole transport layer contains the dopant material, while the high-resistance layer does not, so the resistivity of the high-resistance layer can be made higher than that of the hole transport layer. This makes it possible to provide a high-resistance layer that covers at least a portion of the side surface of the hole transport layer.

[0135] In other words, methods for applying solutions to the areas where the hole transport layer and the high-resistance layer are to be formed include: (1) applying the solution to the areas where the hole transport layer and the high-resistance layer are to be formed, and then applying the solution to either the area where the hole transport layer or the high-resistance layer is to be formed; (2) applying the solution to either the area where the hole transport layer or the high-resistance layer is to be formed, and then applying the solution to either the area where the hole transport layer and the high-resistance layer are to be formed; and (3) applying different solutions to the areas where the hole transport layer and the high-resistance layer are to be formed, respectively. By applying the solution to the area where the hole transport layer is to be formed, specifically the central part of the area where both the hole transport layer and the high-resistance layer are to be formed, or by applying the solution to the area where the high-resistance layer is to be formed, specifically the outer periphery of the area where both the hole transport layer and the high-resistance layer are to be formed, a high-resistance layer can be formed that covers the sides of the hole transport layer.

[0136] The dopant concentration in the solution containing the dopant material is preferably 30 mg / mL or less, more preferably 20 mg / mL or less, even more preferably 0.05 mg / mL to 10 mg / mL, and particularly preferably 0.1 mg / mL to 10 mg / mL.

[0137] Dopant concentrations can be measured by identifying the dopant material using methods such as TOF-SIMS, LC-MS, and GC-MS, and then quantifying it using methods such as liquid chromatography and gas chromatography.

[0138] The high-resistance layer may be formed by applying an insulating material. Examples of methods for applying the insulating material include immersion, air knife, dip, spray, wire bar, spin coat, roller, and inkjet methods. Among these, the inkjet method is preferred.

[0139] In one embodiment, the high-resistance layer may be provided so as to cover at least a portion of the side surface of the hole transport layer, or it may be provided so as to be in contact with the entire side surface of the hole transport layer, or it may be provided so as to be in contact with a portion of the side surfaces of the electron transport layer, photoelectric conversion layer, hole transport layer, and second electrode, or it may be provided so as to be in contact with the entire side surfaces of the electron transport layer, photoelectric conversion layer, hole transport layer, and second electrode.

[0140] Furthermore, in an embodiment in which the high-resistance layer is provided so as to cover at least a portion of the side surface of the second electrode, it is preferable that the high-resistance layer be provided in contact with the surface opposite to the surface on the side surface of the second electrode where the laminate and the second electrode are in contact, and that after the second electrode and the side surface of the second electrode are formed, a material having an insulating material is applied to the position in contact with the second electrode and the side surface of the second electrode. [Examples]

[0141] The present invention will be described below with reference to examples and comparative examples. However, the present invention is not limited to the examples individually provided.

[0142] <Example of synthesis> <<Synthesis of Polymer Compounds>> A polymer compound (A-01) was synthesized as a hole transport material through the following reaction.

[0143] [ka]

[0144] In a 100 mL four-necked flask, the above-mentioned dialdehyde compound (0.66 g, 2.0 mmol) and diphosphonate (1.02 g, 2.0 mmol) were placed, and after purging with nitrogen, tetrahydrofuran (75 mL) was added. To this solution, a 1.0 mL / L solution of potassium tertshalbutoxy (6.75 mL, 6.75 mmol) was added dropwise, and the mixture was stirred at room temperature for 2 hours. Then, for end-capturing, diethyl benzylphosphonate and benzaldehyde were added sequentially, and the mixture was stirred for a further 2 hours. Acetic acid (1 mL) was added to terminate the reaction, and the solution was washed with water. After removing the solvent under reduced pressure, the solution was purified by reprecipitation using tetrahydrofuran and methanol to obtain 0.95 g of the high-molecular-weight compound (A-01).

[0145] The obtained polymer compound (A-01) was measured by gel filtration chromatography (GPC), and its number-average molecular weight (in polystyrene terms) was 8500, while its weight-average molecular weight was 20000.

[0146] (Example 1) <Fabrication of photoelectric conversion element modules> A pre-patterned ITO glass substrate was used as the first substrate and / or the first electrode. The ITO glass substrate used had an ITO thickness of 150 nm and a surface resistance of 15 Ω / □.

[0147] A tin oxide colloid solution (Ceramase S-8, manufactured by Taki Chemical Co., Ltd.) was patterned onto a patterned ITO glass substrate using an inkjet method, and an electron transport layer was obtained by heating and drying at 120°C for 10 minutes. The pattern deposition was programmed to avoid applying the tin oxide colloid solution to the patterned areas. The thickness of the electron transport layer was set to 30 nm.

[0148] Next, lead(II) iodide (0.53 g), lead(II) bromide (0.07 g), formamidine iodide (0.21 g), methylammonium bromide (0.01 g), and cesium iodide (0.02 g) were added to N,N-dimethylformamide (0.8 mL) and dimethyl sulfoxide (0.2 mL), and the mixture was stirred. The resulting solution was then patterned onto the electron transport layer using an inkjet method, and the entire substrate was immersed in a chlorobenzene bath to form a film. The perovskite layer (photoelectric conversion layer) was then obtained by heating and drying at 150°C for 30 minutes. The thickness of the perovskite layer was set to 400 nm.

[0149] Next, a 1 mM solution of 2-propanol containing 5-aminopentanoic acid hydroiodide was patterned onto the formed perovskite layer using an inkjet method to obtain a passivation layer.

[0150] Next, the polymer compound (A-01) (38.1 mg) produced in the synthesis example was dissolved in chlorobenzene (3.0 mL). The resulting hole transport solution was then applied to the passivation layer and the entire surface of the resulting laminate using an inkjet method to deposit the hole transport material.

[0151] Next, a dopant solution was prepared by dissolving 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (D-19) in a 2-propanol solution to a concentration of 1 mg / mL. The prepared dopant solution was then coated onto the hole transport material applied to the passivation layer using an inkjet method to obtain a hole transport layer. The thickness of the hole transport layer was set to 60 nm.

[0152] Furthermore, the dopant solution was applied only to the area on the passivation layer where the hole transport layer was to be formed. The area on the passivation layer containing the dopant material is referred to as the hole transport layer, and the hole transport material provided on a part of the side surface of the resulting laminate was not coated with the dopant material. The area to which only this hole transport solution was applied is referred to as the high-resistance layer.

[0153] Finally, gold was vacuum deposited onto the aforementioned laminate to a thickness of 60 nm using a deposition mask to obtain a second electrode. In this way, the solar cell module of Example 1, which is a forward-type photoelectric conversion module as shown in Figure 5, was obtained. Note that a photoelectric conversion module was fabricated in which three photoelectric conversion elements were electrically connected in series.

[0154] <Evaluation of photoelectric conversion characteristics> The photoelectric conversion module fabricated in Example 1 was tested using a solar simulator (SS-80XIL, manufactured by Eiko Seiki Co., Ltd.) at AM1.5G and 100mW / cm². 2 Under these conditions, the current-voltage characteristics were measured using a solar cell evaluation system (System House Sunrise, product name: Measurement Excel Add-in W32-B2900SOL4M-R) while irradiating with light. The photoelectric conversion efficiency in the photoelectric conversion characteristics (initial characteristics) was calculated from the obtained current-voltage curve. Four similar photoelectric conversion element modules were fabricated, and the average of the obtained conversion efficiencies was defined as the photoelectric conversion efficiency η (%). When calculating the average photoelectric conversion efficiency, short-circuited modules were excluded.

[0155] <Measurement of resistivity> The resistivity of the hole transport layer and high-resistivity layer was measured using an element in which the hole transport layer and high-resistivity layer were formed on a pre-patterned ITO glass substrate, followed by 60 nm of gold vacuum deposition using a deposition mask. The resistance values ​​of the hole transport layer and high-resistivity layer were determined using an impedance analyzer (Toyo Technica Co., Ltd., product name: High-Performance Electrochemical Measurement System SP-300) (measurement mode: voltage-controlled impedance measurement, measurement temperature: 23°C, measurement frequency: 7 MHz ~ 500 mHz, AC amplitude: 10 mV) of the fabricated element. The resistivity of the hole transport layer and high-resistivity layer was calculated by multiplying the obtained resistance value by the element area and then dividing by the element film thickness.

[0156] <Evaluation of insulating properties> The insulating properties of the photoelectric conversion module fabricated in Example 1 were evaluated. Insulation properties were determined by the presence or absence of short circuits during the evaluation of the photoelectric conversion element characteristics, and were evaluated based on the following evaluation criteria. The results are shown in Table 1. -Evaluation Criteria- ○: No short circuit ×: One or more short circuits

[0157] (Examples 2-8) Except for changing the hole transport material and dopant material in Example 1 to the hole transport material and dopant material shown in Table 1, the photoelectric conversion elements and photoelectric conversion modules of Examples 2 to 8 were fabricated and evaluated in the same manner as in Example 1. The results are shown in Table 1. The abbreviations used in Table 1 are as follows: P3HT: Poly(3-hexylthiophene-2,5-diyl) (manufactured by Sigma-Aldrich) • PolyTPD: Poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] (manufactured by Sigma-Aldrich) Spiro-OMeTAD: 2,2',7,7'-Tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-Spirobifluorene (manufactured by Sigma-Aldrich)

[0158] (Example 9) In Example 9, the photoelectric conversion element and photoelectric conversion module were fabricated and evaluated in the same manner as in Example 1, except that instead of the solution in which the hole transport material A-01 was dissolved in Example 1, a solution of 16.9 mg of Spiro-OMeTAD 2 dissolved in 3.0 mL of chlorobenzene was used, and instead of the solution in which the dopant material D-19 was dissolved, a solution of 12.8 mg of lithium bis(trifluoromethane)sulfonyliimide (LiTFSI, manufactured by Sigma-Aldrich) and 18.3 mg of 4-t-butylpyridine (tBP, manufactured by Sigma-Aldrich) dissolved in 31 mL of 2-propanol was used. The results are shown in Table 1.

[0159] (Examples 10-12) Except for changing the concentration of the dopant material in the dopant solution in Example 1 as shown in Table 1, the photoelectric conversion elements and photoelectric conversion modules of Examples 10 to 12 were fabricated and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0160] [Table 1]

[0161] <Changes to the high-resistance layer formation process> In Example 1, the photoelectric conversion elements and photoelectric conversion modules of Examples 13 to 16 were fabricated and evaluated in the same manner as in Example 1, except that the high-resistance layer formation process was modified as follows. In addition, in Example 1, the photoelectric conversion elements and photoelectric conversion modules of Examples 17 to 19 were fabricated and evaluated in the same manner as in Example 1, except that an insulating material was used instead of a hole transport material to form the high-resistance layer. The results are shown in Table 2.

[0162] (Examples 13-14) <High resistance layer formation process> After pattern coating of dopant solutions with the dopant concentrations shown in Table 2 into the areas where the hole transport layer was to be formed, the hole transport solution was then pattern coated into the areas where the hole transport layer and high-resistance layer were to be formed.

[0163] (Examples 15-16) <High resistance layer formation process> Two inkjet heads, one for the hole transport solution and one for the dopant solution, were used to simultaneously pattern coat the two solutions. The dopant solution used was a chlorobenzene solution containing the dopant material at the concentrations shown in Table 2. The dopant solution was pattern coated in the area where the hole transport layer was to be formed, and the hole transport solution was pattern coated in the area where the hole transport layer and the high-resistance layer were to be formed.

[0164] (Example 17) The photoelectric conversion element and photoelectric conversion module of Example 17 were fabricated and evaluated in the same manner as in Example 1, except that the hole transport material in Example 1 was changed to a propylene glycol solution containing 40% by mass of aluminum oxide (Merck) (40% aluminum oxide solution).

[0165] (Example 18) The photoelectric conversion element and photoelectric conversion module of Example 18 were fabricated and evaluated in the same manner as in Example 1, except that the hole transport material in Example 1 was changed to a propylene glycol solution containing 40% by mass of zirconium oxide (Merck) (40% zirconium oxide solution).

[0166] (Example 19) The photoelectric conversion element and photoelectric conversion module of Example 19 were fabricated and evaluated in the same manner as in Example 1, except that the hole transport material in Example 1 was changed to a chlorobenzene solution containing 10% by mass of polystyrene (Merck) (10% polystyrene solution).

[0167] [Table 2]

[0168] (Example 20) In the hole transport layer formation process of Example 1, two inkjet heads, one for the hole transport material-containing solution and the other for the dopant material-containing solution, were used to simultaneously pattern coat the two solutions to form a hole transport layer 6 with a dopant concentration gradient. Except for this, the photoelectric conversion element and photoelectric conversion module of Example 20 were fabricated and evaluated in the same manner as in Example 1. Specifically, during pattern coating, the discharge amounts of the inkjet head for the hole transport material-containing solution and the inkjet head for the dopant material-containing solution were continuously varied to form a dopant concentration distribution in the hole transport layer such that the dopant concentration gradient was higher on the photoelectric conversion layer side and lower on the second electrode side, as shown in Table 3. The results are shown in Table 3.

[0169] (Example 21) In Example 20, the photoelectric conversion element and photoelectric conversion module of Example 21 were fabricated and evaluated in the same manner as in Example 1, except that the hole transport layer 6 was formed such that the dopant concentration gradient was lower on the photoelectric conversion layer side and higher on the second electrode side in the stacking direction of the laminate (z-axis direction as shown in Figure 5). The results are shown in Table 3.

[0170] (Example 22) In Example 20, the photoelectric conversion element and photoelectric conversion module of Example 22 were fabricated and evaluated in the same manner as in Example 1, except that the hole transport layer 6 was formed such that the dopant concentration gradient was lower on the photoelectric conversion layer side, higher in the central part of the hole transport layer, and lower on the second electrode side in the stacking direction of the laminate (z-axis direction as shown in Figure 5). The results are shown in Table 3.

[0171] (Example 23) In Example 20, the photoelectric conversion element and photoelectric conversion module of Example 23 were fabricated and evaluated in the same manner as in Example 1, except that the hole transport layer 6 was formed such that the dopant concentration gradient was higher on the photoelectric conversion layer side, lower in the central part of the hole transport layer, and higher on the second electrode side in the stacking direction of the laminate (z-axis direction as shown in Figure 5). The results are shown in Table 3.

[0172] [Table 3]

[0173] (Comparative Example 1) In Comparative Example 1, a photoelectric conversion element and a photoelectric conversion element module were fabricated and evaluated in the same manner as in Example 1, except that a high-resistance layer was not provided and a dopant solution pattern coating was applied to the entire surface of the hole transport material on the passivation layer. The results are shown in Table 4.

[0174] (Comparative Example 2) The photoelectric conversion element and photoelectric conversion element module for Comparative Example 2 were fabricated and evaluated in the same manner as in Comparative Example 1, except that the photoelectric conversion element module was fabricated without coating the dopant solution onto the hole transport material in Comparative Example 1. The results are shown in Table 4.

[0175] (Comparative Example 3) In Comparative Example 3, the photoelectric conversion element and photoelectric conversion element module were fabricated and evaluated in the same manner as in Comparative Example 1, except that, instead of the dopant solution and hole transport solution used in Comparative Example 1, a solution prepared by dissolving dopant material (D-19) (3.81 mg) and hole transport material (A-01) (38.1 mg) in chlorobenzene (3.0 mL) was used, and the resulting mixed solution was inkjet coated onto the perovskite layer to create a hole transport layer. The results are shown in Table 4.

[0176] [Table 4]

[0177] As is clear from Examples 1 to 16, the photoelectric conversion modules of Examples 1 to 16, which have a high-resistance layer 8 covering at least a portion of the side surface of the hole transport layer 6, have excellent insulating properties. Therefore, even when multiple photoelectric conversion elements are electrically connected, short circuits between photoelectric conversion elements can be suppressed, and good photoelectric conversion efficiency can be maintained. On the other hand, in Comparative Examples 1 and 3, when the high-resistance layer was not provided, and instead the hole transport layer was provided in the area where the high-resistance layer was planned to be formed, insulating properties could not be guaranteed. In Comparative Example 2, in addition to not providing a high-resistance layer, the resistivity of the hole transport layer was high and the hole transport performance was poor, resulting in a low photoelectric conversion efficiency of 10% or less, which was outside the practical range.

[0178] Furthermore, in the photoelectric conversion modules of Examples 17 to 19, in which an insulating material was used instead of a hole transport material to form a high-resistance layer 8, even better insulating properties were obtained. Therefore, even when multiple photoelectric conversion elements were electrically connected, short circuits between photoelectric conversion elements could be suppressed, and good photoelectric conversion efficiency could be maintained. In the photoelectric conversion modules of Examples 20 to 23, in which a dopant concentration gradient was provided in the stacking direction of the laminate in the hole transport layer, excellent insulating properties were also obtained. Therefore, even when multiple photoelectric conversion elements were electrically connected, short circuits between photoelectric conversion elements could be suppressed, and good photoelectric conversion efficiency could be maintained.

[0179] Although the present invention has been described above based on various embodiments, the present invention is not limited to the requirements shown in the above embodiments. These points can be modified as long as they do not impair the spirit of the present invention, and can be appropriately determined according to their application.

[0180] Examples of the present invention are as follows: <1> A photoelectric conversion module having a substrate and a plurality of photoelectric conversion elements on the substrate, including a first photoelectric conversion element and a second photoelectric conversion element, Each of the photoelectric conversion elements has a first electrode, a laminate, and a second electrode on the substrate in this order, and the laminate has an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer. The second electrode of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are electrically connected. The photoelectric conversion module is characterized in that it further has a high-resistivity layer between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element, the high-resistivity layer having a higher resistivity than the hole transport layer of the second photoelectric conversion element. <2> At least one of the photoelectric conversion elements covers at least a portion of the side surface of the hole transport layer <1> This is the photoelectric conversion module described in [the document]. <3> The high-resistance layer includes a hole transport material or an insulating material. <1> This is the photoelectric conversion module described in [the document]. <4> The hole transport layer comprises a hole transport material and a dopant material. The high-resistance layer includes the hole transport material and does not include the dopant material. <3> This is the photoelectric conversion module described in [the document]. <5> The difference between the resistivity of the high-resistivity layer and the resistivity of the hole transport layer is 1.0 × 10 8 The above is Ωcm or more <1> from <4> It is a photoelectric conversion module as described in one of the following. <6> The high-resistance layer covers the entire side surface of the laminate of the second photoelectric conversion element. <1> from <5> It is a photoelectric conversion module as described in one of the following. <7> The second electrode has a side portion that covers a part of the side surface of the laminate, The side portion of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are in contact with each other. <1> from <6> It is a photoelectric conversion module as described in one of the following. <8> The plurality of photoelectric conversion elements are electrically connected in series. <1> from <7> It is a photoelectric conversion module as described in one of the following. <9> A step of forming a first photoelectric conversion element and a second photoelectric conversion element on a substrate, each having a first electrode, a laminate, and a second electrode in that order, The process includes forming a high-resistivity layer between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element, with a resistivity higher than that of the hole transport layer of the second photoelectric conversion element. The laminate comprises an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer. The method for manufacturing a photoelectric conversion module is characterized in that the second electrode of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are electrically connected. <10> The process for forming the first photoelectric conversion element and the second photoelectric conversion element is a combination of the following (1) to (3): (1) A combination of two mixed solutions containing a dopant material and a hole transport material, wherein the dopant material has a different concentration. (2) A combination of a hole transport solution containing the hole transport material or a dopant solution containing the dopant material and one or more of the mixed solutions, (3) Combinations of the hole transport solution and the dopant solution, The process involves applying one of the combinations of the above to the regions where the hole transport layer and the high-resistance layer are to be formed. <9> This is a method for manufacturing the photoelectric conversion module described above. <11> The process of forming the hole transport layer and the high-resistance layer is to use a combination of the hole transport solution and the dopant solution, apply the hole transport solution to the area on the photoelectric conversion layer where the hole transport layer is to be formed and to the area where the high-resistance layer is to be formed, which is at least a part of the side surface of the hole transport layer, and apply the dopant solution to the area where the hole layer is to be formed. <10> This is a method for manufacturing the photoelectric conversion module described above. <12> The aforementioned <1> from <8> This is an electronic device having a photoelectric conversion module as described in any of the following. <13> The aforementioned <1> from <8> This is a power supply module having a photoelectric conversion module as described in any of the above. <14> The aforementioned <1> from <8> It is a building material having a photoelectric conversion module as described in any of the above. [Explanation of Symbols]

[0181] 1. First substrate 2. First electrode 3 Electron transport layer 4 Perovskite layer 5 Passivation Layer 6 Hole Transport Layer 7. Second electrode 7a Side portion of the second electrode 8 High resistance layer 10, 20, 30, 40, 10A~10C, 20A~20E, 40A~40C Photoelectric conversion elements 100, 200, 400 Photoelectric Conversion Modules 101 Second circuit board 102 Sealing member 202 Power IC 203 Energy Storage Devices 209 Equipment circuit 1000 Building materials 1001 Glass [Prior art documents] [Patent Documents]

[0182] [Patent Document 1] Patent No. 5673799

Claims

1. A photoelectric conversion module having a substrate and a plurality of photoelectric conversion elements on the substrate, including a first photoelectric conversion element and a second photoelectric conversion element, Each of the photoelectric conversion elements has a first electrode, a laminate, and a second electrode on the substrate in this order, and the laminate has an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer. The second electrode of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are electrically connected. The photoelectric conversion module is characterized in that it further has a high-resistivity layer between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element, the high-resistivity layer having a higher resistivity than the hole transport layer of the second photoelectric conversion element.

2. The photoelectric conversion module according to claim 1, wherein the high-resistance layer covers at least a portion of the hole transport layer of the second photoelectric conversion element.

3. The photoelectric conversion module according to claim 1, wherein the high-resistance layer comprises a hole transport material or an insulating material.

4. The hole transport layer comprises a hole transport material and a dopant material. The photoelectric conversion module according to claim 3, wherein the high-resistance layer includes the hole transport material but does not include the dopant material.

5. The difference between the resistivity of the high-resistivity layer and the resistivity of the hole transport layer is 1.0 × 10 ８ The photoelectric conversion module according to claim 1, wherein the value is Ωcm or greater.

6. The photoelectric conversion module according to claim 2, wherein the high-resistance layer covers the entire side surface of the laminate of the second photoelectric conversion element.

7. The second electrode has a side portion that covers a part of the side surface of the laminate, The photoelectric conversion module according to claim 1, wherein the side portion of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are in contact.

8. The photoelectric conversion module according to claim 1, wherein the plurality of photoelectric conversion elements are electrically connected in series.

9. A step of forming a first photoelectric conversion element and a second photoelectric conversion element on a substrate, each having a first electrode, a laminate, and a second electrode in that order, The process includes forming a high-resistivity layer between the second electrode of the first photoelectric conversion element and the laminate of the second photoelectric conversion element, with a resistivity higher than that of the hole transport layer of the second photoelectric conversion element. The laminate comprises an electron transport layer, a hole transport layer, and a photoelectric conversion layer between the electron transport layer and the hole transport layer. A method for manufacturing a photoelectric conversion module, characterized in that the second electrode of the first photoelectric conversion element and the first electrode of the second photoelectric conversion element are electrically connected.

10. The process for forming the first photoelectric conversion element and the second photoelectric conversion element is a combination of the following (1) to (3): (1) A combination of two or more mixed solutions containing a dopant material and a hole transport material, wherein the concentration of the dopant material differs. (2) A combination of a hole transport solution containing the hole transport material or a dopant solution containing the dopant material and one or more of the mixed solutions, (3) Combinations of the hole transport solution and the dopant solution, A method for manufacturing a photoelectric conversion module according to claim 9, comprising the step of applying any combination of the above to the regions where the hole transport layer and the high-resistance layer are to be formed.

11. A method for manufacturing a photoelectric conversion module according to claim 10, wherein the step of forming the hole transport layer and the high-resistance layer is to use a combination of the hole transport solution and the dopant solution, apply the hole transport solution to the area where the high-resistance layer is to be formed, which is at least a part of the side surface of the hole transport layer, and apply the dopant solution to the area where the hole transport layer is to be formed.

12. An electronic device having the photoelectric conversion module described in claim 1.

13. A power supply module having the photoelectric conversion module described in claim 1.

14. A building material having the photoelectric conversion module described in claim 1.

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