Photoelectric conversion element

Abstract

The present invention addresses the problem of providing a photoelectric conversion element having high initial conversion efficiency and less deterioration (reduction) of conversion efficiency when used continuously for a long period of time. In order to solve this problem, the present invention provides the following photoelectric conversion element. A photoelectric conversion element according to the present invention has a first electrode, a second electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode and including a crystal having a perovskite structure. The photoelectric conversion element is characterized by having a charge transport layer between the photoelectric conversion layer and the first electrode, the charge transport layer including a phthalocyanine compound and an aromatic ring compound different from the phthalocyanine compound and having a hydroxyl group.

Description

Technical Field

[0001] The present invention relates to a photoelectric conversion element. Background Art

[0002] In order to solve the problem of depletion of fossil energy and global environmental problems caused by the use of fossil energy, research on renewable and clean alternative energy sources such as solar, wind, or hydropower has been actively carried out. Among them, the interest in solar cells that directly convert sunlight into electricity has increased significantly. As used herein, the term "solar cell" refers to a cell that generates current-voltage using the photovoltaic effect in which light energy is absorbed from sunlight to generate electrons and holes.

[0003] Currently, solar cells based on n-p diode type single crystal silicon (Si) with a light energy conversion efficiency exceeding 20% are well-known and have been actually used for solar power generation. However, solar cells require high-temperature treatment processes, and the price of the material itself is high, so there is a problem of high unit power cost. In addition, in terms of silicon resources, supply is also an issue.

[0004] Meanwhile, solar cells using organic materials (hereinafter also referred to as "organic solar cells") do not require high-temperature treatment processes and are sheet substrates that can be produced by a so-called roll to roll system, so the cost can be reduced. For the practical application of organic solar cells, further improvement in power generation efficiency and durability is required. In particular, as a photoelectric conversion layer, the development of crystals having a perovskite structure (including perovskite crystals) as materials for practical application of solar cells has progressed because the crystals have excellent photoelectric conversion properties. For example, Patent Document 1 describes that the open-circuit voltage is increased by doping fullerene C60 in an intermediate layer on the perovskite layer. Patent Document 2 describes that the durability is improved when an intermediate layer containing thiocyanic acid exists on the perovskite layer. Patent Document 3 describes that the photoelectric conversion efficiency is improved when an intermediate layer containing 2-phenylethylammonium bromide exists on the perovskite layer.

[0005] [Prior Art Documents]

[0006] [Patent Documents]

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-13982

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2019-71500

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2022-27575 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] According to the research conducted by the inventors of the present invention, in each of the photoelectric conversion elements described in Patent Documents 1 to 3, it is impossible to suppress the surface change of the crystal having a perovskite structure when energized, and there is a problem that the conversion efficiency deteriorates (decreases) when the photoelectric conversion element is continuously used for a long time.

[0012] Therefore, an object of the present invention is to provide a photoelectric conversion element having a high initial conversion efficiency and in which the deterioration (decrease) of the conversion efficiency is less when the photoelectric conversion element is continuously used for a long time.

[0013] Solutions to the Problems

[0014] A first aspect of the present invention is to provide a photoelectric conversion element including: a first electrode; a second electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode and containing a crystal having a perovskite structure, wherein the photoelectric conversion element includes a charge transport layer (including a hole transport layer and an electron transport layer) between the photoelectric conversion layer and the first electrode, and the charge transport layer contains a phthalocyanine compound (including a metal-free phthalocyanine, a metal phthalocyanine, or a phthalocyanine derivative derived from a metal-free phthalocyanine or a metal phthalocyanine) and an aromatic ring compound having a hydroxyl group different from the phthalocyanine compound.

[0015] A second aspect of the present invention is to provide a photoelectric conversion element including: a first electrode; a second electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode and containing a crystal having a perovskite structure, wherein the photoelectric conversion element includes a charge transport layer between the photoelectric conversion layer and the first electrode, and the charge transport layer contains a hole transporting compound and an aromatic ring compound represented by the following general formula [1]:

[0016] [Chemical formula 1]

[0017]

[0018] In the general formula [1], R 1 to R 4 each independently in each repeating unit and independently for the "n" repeating units represents hydrogen, a halogen atom, a hydroxyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted organic group, "n" represents an integer of 3 to 20, and the compound has at least one hydroxyl group in its molecule.

[0019] Effects of the Invention

[0020] According to the present invention, it is possible to provide a photoelectric conversion element in which a decrease in conversion efficiency is suppressed even when the photoelectric conversion element is continuously used for a long time. Brief Description of the Drawings

[0021] Figure 1 is a schematic cross-sectional view in the thickness direction of a photoelectric conversion element according to a first embodiment of the present invention.

[0022] Figure 2 is a schematic cross-sectional view in the thickness direction of a photoelectric conversion element according to a second embodiment of the present invention.

[0023] Figure 3 is a perspective view schematically showing an example of an application example of a moving body including the photoelectric conversion element of the present invention.

[0024] Figure 4 is a perspective view schematically showing another example of an application example of a building material including the photoelectric conversion element of the present invention. Detailed Description

[0025] <First Embodiment and Second Embodiment>

[0026] The photoelectric conversion element of the present invention is a photoelectric conversion element including the following: a first electrode; a second electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode and containing a crystal having a perovskite structure, and a charge transport layer is included between the photoelectric conversion layer and the first electrode. In addition, the charge transport layer according to the present invention has any one of the following features (1) and (2).

[0027] (1) The charge transport layer contains a phthalocyanine compound and an aromatic ring compound having a hydroxyl group different from the phthalocyanine compound. In the present invention, the phthalocyanine compound includes phthalocyanine and phthalocyanine derivatives (compounds derived from phthalocyanine).

[0028] (2) The charge transport layer contains a hole transport compound and an aromatic ring compound having a calixarene structure.

[0029] First, the above feature (1) will be described.

[0030] As a result of research conducted by the inventors of the present invention, the inventors have found that when the photoelectric conversion element includes the charge transport layer of the above feature (1), a photoelectric conversion element having excellent surface stability of a crystal having a perovskite structure is obtained. The details of the reason for obtaining high stability in the present invention are not clear, but it is assumed as follows.

[0031] ​​​​When a phthalocyanine compound in the form of particles forms a film, high crystallinity is maintained, and the original charge transport ability of phthalocyanine can be exerted. In addition, in the research conducted by the inventors of the present invention so far, it is assumed that when the photoelectric conversion layer contains a perovskite compound, unevenness on the order of submicrons is generated on the surface. Therefore, the interface bonding is improved by filling the concave portions of such unevenness with phthalocyanine compound particles, and high photoelectric conversion efficiency can be obtained. However, it has been found that changes in the surface of the crystal having a perovskite structure during energization cannot be suppressed in the lamination of phthalocyanine compound particles. In the present invention, by introducing an aromatic ring compound having a hydroxyl group different from the phthalocyanine compound into the charge transport layer containing phthalocyanine compound particles, deterioration of the crystal having a perovskite structure can be suppressed. It is speculated that the aromatic ring compound having a hydroxyl group enters between the phthalocyanine compound particles and the crystal having a perovskite structure. The crystal having a perovskite structure is a hydrogen-bonded crystal, so it is considered that the aromatic ring compound having a hydroxyl group generates a hydrogen bond interaction with the surface of the crystal having a perovskite structure. It is considered that through the interaction with the surface of the crystal having a perovskite structure, when the crystal having a perovskite structure becomes a stable state during energization, the surface of the crystal is chemically fixed by the above interaction, so that changes in the surface of the crystal are suppressed.

[0032] The inventors of the present invention believe that when an aromatic ring compound having a hydroxyl group is combined with a phthalocyanine compound, it can interact with the surface of the crystal having a perovskite structure. It is speculated that the condensed rings of the phthalocyanine compound strongly interact with each other, so the aromatic ring of the aromatic ring compound having a hydroxyl group interacts with the surface of the phthalocyanine compound. As a result, it is considered that the interaction of the hydroxyl group of the aromatic ring of the aromatic ring compound having a hydroxyl group in the direction of the crystal having a perovskite structure increases. When the content of the phthalocyanine compound in the charge transport layer is set to 100 parts by mass, from the viewpoint of the interaction strength with the surface of the crystal having a perovskite structure, it is preferable to add the aromatic ring compound having a hydroxyl group in the charge transport layer in a content (parts by mass) range of 0.5 parts by mass or more and 50 parts by mass or less. In addition, from the viewpoint of molecular size, in order to facilitate the interaction with the surface of the crystal having a perovskite structure, the molecular weight of the aromatic ring compound having a hydroxyl group is preferably 10,000 or less.

[0033] In addition, it has been found that when the number of hydroxyl groups in the aromatic ring compound is greater than the number of hydroxyl groups in the phthalocyanine compound, the surfaces of the aromatic ring compound and the crystal having a perovskite structure are likely to interact with each other, and thus changes in the surface of the crystal are likely to be suppressed. In the present invention, the number of hydroxyl groups in the aromatic ring compound is preferably greater than the number of hydroxyl groups in the phthalocyanine compound. In particular, from the viewpoint of the hydrogen bond strength, the number of hydroxyl groups in the aromatic ring compound having a hydroxyl group is more preferably 3 or more, and particularly preferably 4 or more. The aromatic ring compound having a hydroxyl group more preferably has a cyclic structure because the hydrogen bond density between the compound and the surface of the crystal having a perovskite structure increases, and the compound preferably has, for example, a calixarene structure such as calix-4-arene or calix-8-arene. It has been found that a combination obtained by mixing a plurality of calix-4-arene is particularly excellent.

[0034] In the present invention, the charge transport layer may contain one aromatic ring compound, but preferably contains a plurality of aromatic ring compounds. Specifically, the aromatic ring compound having a calixarene structure preferably used in the present invention is a compound represented by the following general formula [1].

[0035] [Chemical formula 2]

[0036]

[0037] In the general formula [1], R 1 to R 4 each independently in each repeating unit and independently for the "n" repeating units represents hydrogen, a halogen atom, a hydroxyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted organic group, "n" represents an integer of 3 to 20, and the compound has at least one hydroxyl group in its molecule. In addition, the present invention relates to a photoelectric conversion element including: a first electrode; a second electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode and containing a crystal having a perovskite structure, wherein the photoelectric conversion element includes a charge transport layer between the photoelectric conversion layer and the first electrode, and the charge transport layer contains a hole transport compound and an aromatic ring compound represented by the general formula [1]. In the present invention, the structure of the compound can be determined by analysis based on data measured by, for example, a nuclear magnetic resonance apparatus (NMR).

[0038] Examples of the organic group are groups represented by the general formula -Y-Ar, where -Y- represents -CH=N-, -CH=CH-, or -N=N-, and Ar represents a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted heterocyclic group.

[0039] By R 1 to R 4Examples of the aromatic hydrocarbons each represented thereby and the aromatic hydrocarbon represented by Ar include benzene, naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene. In addition, examples of the heterocycles represented by Ar include furan, thiophene, pyridine, indole, benzothiazole, carbazole, benzocarbazole, acridone, dibenzothiophene, benzoxazole, benzotriazole, oxathiazole, thiazole, phenazine, cinnoline, and benzocinnoline.

[0040] In addition, the substituents that the aromatic hydrocarbon group each represented by R 1 to R 4 can have and the substituents that Ar can have include: alkyl groups such as methyl, ethyl, propyl, and butyl; alkoxy groups such as methoxy and ethoxy; dialkylamino groups such as dimethylamino and diethylamino; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl; halogen atoms such as fluorine, chlorine, and bromine atoms; hydroxyl groups; nitro groups; cyano groups; and halomethyl groups.

[0041] In the aromatic ring compound having a calixarene structure represented by the general formula [1], "n" preferably represents 4 or 8. In addition, for the "n" repeating units, R 1 preferably each independently represents a halogen atom or a hydroxyl group, and at least one R 1 represents a hydroxyl group. In addition, for the "n" repeating units, R 3 preferably each independently represents a nitrophenylazo group or a dinitrophenylazo group.

[0042] Specific examples of the aromatic ring compound having a calixarene structure preferably used in the present invention are given below. In the present invention, the charge transport layer preferably contains at least one compound selected from the group consisting of the following compounds as the aromatic ring compound: the compound represented by the following formula [C-1]; the compound represented by the following formula [C-2]; the compound represented by the following formula [C-3]; and the compound represented by the following formula [C-4], and the charge transport layer more preferably contains the compound represented by the following formula [C-1], the compound represented by the following formula [C-2], the compound represented by the following formula [C-3], and the compound represented by the following formula [C-4] as the aromatic ring compound.

[0043] [Chemical formula 3]

[0044]

[0045] [Chemical formula 4]

[0046]

[0047] [Chemical formula 5]

[0048]

[0049] [Chemical formula 6]

[0050]

[0051] [Chemical Formula 7]

[0052]

[0053] [Chemical Formula 8]

[0054]

[0055] [Chemical Formula 9]

[0056]

[0057] [Chemical Formula 10]

[0058]

[0059] [Chemical Formula 11]

[0060]

[0061] In addition to the aromatic ring compound having a calixarene structure, an aromatic ring compound having a non-cyclic structure can be used as an aromatic ring compound having a hydroxyl group different from the phthalocyanine compound. Specific examples thereof include phenol, 1-naphthol, benzyl alcohol, cresol, benzene triol, carboxylic acid, hydroquinone, benzoic acid, phthalic acid, terephthalic acid, and catecholamine.

[0062] In the present invention, the phthalocyanine compound is preferably a metal phthalocyanine compound. The phthalocyanine compound used in the present invention may have a metal ligand, and for example, Ga, Cu, Ti, and Zn are used as the coordination metals. Among them, from the viewpoint of crystallinity, Ga is preferred. From the viewpoint of the interaction with the aromatic ring compound having a hydroxyl group, the phthalocyanine compound is more preferably a gallium phthalocyanine compound, and particularly preferably a hydroxygallium phthalocyanine compound.

[0063] In addition, the inventors of the present invention have found the following effects: In addition to the phthalocyanine compound, by combining a hole transporting compound and an aromatic ring compound having a calixarene structure represented by the general formula [1], the aromatic ring compound interacts with the surface of the crystal having a perovskite structure and stabilizes the surface chemically. That is, the charge transport layer is the charge transport layer of the above-mentioned feature (2). In particular, calix-4-arene in which "n" in the general formula [1] represents 4 is preferably used as the aromatic ring compound having a calixarene structure. In addition, the following compounds are preferred: in the general formula [1], R 1 For each of the "n" repeating units independently represents a halogen atom or a hydroxyl group, at least one R 1 represents a hydroxyl group, and R 3For each of the "n" repeating units, it independently represents a nitrophenylazo group or a dinitrophenylazo group. In particular, from the viewpoint of the affinity of the hole transporting compound, it is preferable to use a mixture of multiple calix-4 arenes.

[0064] The hole transporting compound combined with the aromatic ring compound having a calixarene structure is not particularly limited, but 2,2′,7,7′-tetra-(N,N-di-4-methoxyphenylamino)-9,9′-spirobifluorene (spiro-OMeTAD) and poly(triarylamine) (PTAA) are preferable.

[0065] Through the above mechanism, when each structure affects each other synergistically, the effects of the present invention can be achieved.

[0066] The embodiments of the present invention will be described in detail below. The present invention is not limited to the following embodiments, and the following embodiments with appropriate changes and modifications based on the common knowledge of those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

[0067] As used herein, the term "layer" not only means a layer with a clear boundary or a layer with a flat thin film shape, but also means a layer with a concentration gradient in which the elements to be introduced gradually change, or may mean a layer that forms an intricate structure together with other layers. In addition, the elemental analysis of the layer can be performed, for example, by performing TOF-SIMS / FE-TEM / EDS ray analysis measurement on the cross-section of the photoelectric conversion element to determine the elemental distribution of specific elements.

[0068] Figure 1 It is a schematic cross-sectional view in the thickness direction of a photoelectric conversion element according to the first embodiment of the present invention. The photoelectric conversion element includes: a substrate 2; and a second electrode 3, an electron transport layer 4, a photoelectric conversion layer 5, a charge transport layer 8, a hole transport layer 6, and a first electrode 7 disposed on the substrate 2. The first electrode 7 is an anode, and the second electrode 3 is a cathode, and current can be extracted by connecting the first electrode 7 and the second electrode 3 with an external circuit.

[0069] Figure 2 It is a schematic cross-sectional view in the thickness direction of a photoelectric conversion element according to the second embodiment of the present invention.

[0070] The photo-electric conversion layer 5 is photo-excited by light that passes through the substrate 2, the second electrode 3, and the electron transport layer 4 or through the first electrode 7, the hole transport layer 6, and the charge transport layer 8 to generate electrons or holes. That is, the photo-electric conversion layer 5 generates a voltage between the first electrode 7 and the second electrode 3. The electron transport layer 4 is a layer disposed between the photo-electric conversion layer 5 and the two electrodes 3 and 7, and in some cases, the electron transport layer 4 may not be formed. The photo-electric conversion element of the present invention may have a form in which a plurality of electron transport layers 4, photo-electric conversion layers 5, and hole transport layers 6 are stacked, or the electrodes may be configured as needed. The photo-electric conversion elements to be stacked may be photo-electric conversion elements including, for example, silicon or CIGS. This form is sometimes referred to as a tandem structure. Each component will be described below.

[0071] [Substrate]

[0072] The photo-electric conversion element 1 of the present invention may include a substrate 2, and examples thereof include transparent glass substrates such as soda-lime glass and alkali-free glass; ceramic substrates; and transparent plastic substrates. When light is obtained from the first electrode 7 side, an opaque material may be used as the substrate 2, and when light is obtained from the second electrode 3 side, the substrate 2 is formed of a transparent material. In addition, both the first electrode 7 and the second electrode 3 may be formed of a transparent material.

[0073] [Electrode]

[0074] The material of the first electrode 7 or the second electrode 3 is not particularly limited, and known materials can be used. Examples thereof include: metals such as gold, silver, titanium, and copper; sodium; sodium-potassium alloy; lithium; magnesium; aluminum; magnesium-silver mixture; magnesium-indium mixture; aluminum-lithium alloy; Al / Al 2 O 3 mixture; and Al / LiF mixture. Examples of transparent electrode materials include: conductive transparent materials such as CuI, indium tin oxide (ITO), SnO 2 , aluminum zinc oxide (AZO), indium zinc oxide (IZO), gallium zinc oxide (GZO), fluorine-doped tin oxide (FTO), and antimony-doped tin oxide (ATO); and conductive transparent polymers. These materials may be used alone or in combination. At least one of the first electrode 7 or the second electrode 3 on the light incident side is a transparent electrode, and the other may be a transparent electrode or may also be used as a reflective layer formed of a light-reflective material. When the first electrode 7 is on the light incident side, the second electrode 3 and the substrate 2 may be a transparent electrode and a reflective layer, respectively. The transparent electrode may be a patterned electrode.

[0075] [Photo-electric conversion layer]

[0076] The photo-electric conversion layer 5 contains a crystal having a perovskite structure. The crystal having a perovskite structure used in the present invention is preferably a crystal of a compound represented by the following general formula [2] in which a hydrogen bond is likely to be formed on the surface.

[0077] R-M-X 3 [2]

[0078] In the general formula [2], R represents either an organic molecule or an inorganic atom or both, M represents a metal atom, and X represents a halogen atom or a chalcogen atom.

[0079] When R in the general formula [2] is an organic molecule, it is preferably represented by, for example, C p N m H n ("p", "m", and "n" each represent a positive integer). Specific examples of the organic molecule include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, ethylbutylamine, imidazole, azole, pyrrole, aziridine, azirine, azetidine, azete, imidazoline, carbazole, aniline, pyridine, methylcarboxamide, ethylcarboxamide, propylcarboxamide, butylcarboxamide, pentylcarboxamide, hexylcarboxamide, formamidinium, an ion of guanidine (e.g., methylammonium (CH 3 NH 3 )) and phenethylammonium. Among them, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, aniline, pyridine, propylcarboxamide, butylcarboxamide, pentylcarboxamide, formamidinium, an ion of guanidine, and phenethylammonium are preferred, and methylamine, ethylamine, propylamine, pentylcarboxamide, formamidinium, and an ion of guanidine are more preferred. In addition, the inorganic atom is not particularly limited, but lithium, cesium, sodium, potassium, and rubidium are preferred. These organic molecules or inorganic atoms can be used alone or in combination.

[0080] The above-mentioned M represents a metal atom, and examples thereof include lead, tin, bismuth, zinc, titanium, antimony, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, and europium. Among them, from the viewpoint of electron orbital overlap, lead, tin, and bismuth are preferred. These metal atoms can be used alone or in combination.

[0081] The above X represents a halogen atom or a chalcogen atom, and examples thereof include chlorine, bromine, iodine, sulfur, and selenium. These halogen atoms or chalcogen atoms can be used alone or in combination. Among them, halogen atoms are preferred because when halogen atoms are introduced into the structure, the organic-inorganic perovskite compound is easily soluble in organic solvents and can thus be applied to inexpensive printing methods and the like. In addition, iodine is more preferred because the organic-inorganic perovskite compound has a narrow bandgap.

[0082] Specifically, MAPbI 3 、Cs 5 (MA 0.17 FA 0.83 ) 95 Pb(I 0.83 Br 0.17 ) 3 or CsPbI 3 is preferred. "MA" represents methylammonium, and "FA" represents formamidinium.

[0083] The organic-inorganic perovskite compound preferably has a cubic crystal structure in which the metal atom M, the organic molecule R, and the halogen atom or chalcogen atom X are respectively arranged at the body-centered position, each vertex, and the face-centered position. The details are not yet clear, but it is speculated that when the organic-inorganic perovskite compound has such a structure, the orientation of the octahedra in the lattice can be easily changed, so that the electron mobility in the organic-inorganic perovskite compound increases and the photoelectric conversion efficiency of the photoelectric conversion element is improved.

[0084] The organic-inorganic perovskite compound used in the present invention is preferably a crystalline semiconductor. The term "crystalline semiconductor" means a semiconductor capable of measuring the X-ray scattering intensity distribution to detect scattering peaks. When the organic-inorganic perovskite compound is a crystalline semiconductor, the electron mobility in the organic-inorganic perovskite compound increases and the photoelectric conversion efficiency of the photoelectric conversion element is improved.

[0085] The thickness of the photoelectric conversion layer according to the present invention is preferably 5 nm or more and 1,000 nm or less. When the thickness is 5 nm or more, light can be sufficiently absorbed, and when the thickness is 1,000 nm or less, the generated charges can be transported to each electrode. The more preferred lower limit is 10 nm or more, the more preferred upper limit is 700 nm, the still more preferred lower limit is 15 nm, and the still more preferred upper limit is 500 nm.

[0086] [Charge transport layer]

[0087] The photoelectric conversion element 1 of the present invention includes a charge transport layer 8 between the photoelectric conversion layer 5 and the first electrode 7. In the present invention, it is preferred that the charge transport layer is in contact with the photoelectric conversion layer. As described above, the charge transport layer 8 contains any one of the following: a phthalocyanine compound and an aromatic ring compound having a hydroxyl group different from the phthalocyanine compound; or a hole transport compound and an aromatic ring compound having a calixarene structure.

[0088] The thickness of the charge transport layer 8 is preferably 20 nm or more and 800 nm or less. When the thickness is 20 nm or more, it is easy to sufficiently cover the photoelectric conversion layer 5, so that charge transport can be carried out smoothly, and when the thickness is 800 nm or less, it is easy to satisfactorily transport charges to each electrode. The thickness is more preferably 50 nm or more and 600 nm or less, and still more preferably 50 nm or more and 400 nm or less.

[0089] [Hole transport layer]

[0090] In the present invention, from the viewpoint of the compatibility of the film of the charge transport layer, the photoelectric conversion element 1 preferably includes a hole transport layer 6 between the charge transport layer 8 and the first electrode 7.

[0091] The material of the hole transport layer 6 is not particularly limited, and examples thereof include spirofluorene compounds, triphenylamine compounds, compounds, pyrene compounds, phthalocyanine compounds, carbazole compounds, fluorene compounds, phenylcyclohexane compounds, benzidine compounds, phenoxazine compounds, phenylenediamine compounds, and thiocyanate compounds. From the viewpoint of the compatibility of the film interface, the hole transport compound particularly preferably has an aromatic ring. As the hole transport compound, spiro-OMeTAD, PTAA, or a phthalocyanine compound is preferred.

[0092] [Electron transport layer]

[0093] In the photoelectric conversion element of the present invention, as Figure 1 shown, an electron transport layer 4 can be disposed between the second electrode 3 and the photoelectric conversion layer 5.

[0094] The material of the electron transport layer 4 is not particularly limited, and examples thereof include N-type conductive polymers, N-type low molecular weight organic semiconductors, N-type metal oxides, N-type metal sulfides, alkali metal halides, alkali metals, and surfactants. Specific examples thereof include cyanine group-containing poly(phenylene vinylene), boron-containing polymers, bathocuproine, bathophenanthroline, hydroxyquinolinatoaluminum, oxadiazole compounds, benzimidazole compounds, naphthalene tetracarboxylic acid compounds, perylene derivatives, phosphine oxide compounds, phosphine sulfide compounds, fluorine group-containing phthalocyanines, titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, and zinc sulfide.

[0095] The lower limit of the thickness of the electron transport layer 4 is preferably 1 nm, and the upper limit thereof is preferably 2,000 nm. When the thickness is 1 nm or more, holes can be sufficiently blocked, and when the thickness is 2,000 nm or less, the electron transport layer 4 is less likely to become a barrier during electron transport, so the photoelectric conversion efficiency is improved. The more preferred lower limit of the thickness is 3 nm, the more preferred upper limit thereof is 1,000 nm, the still more preferred lower limit thereof is 5 nm, and the still more preferred upper limit thereof is 500 nm.

[0096] [Photoelectric conversion device]

[0097] The photoelectric conversion device can be formed by using a plurality of the photoelectric conversion elements of the present invention. When a plurality of photoelectric conversion elements are connected, such a photoelectric conversion device may also be referred to as a "photoelectric conversion module". The photoelectric conversion elements can be stacked to increase the output voltage. In addition, the photoelectric conversion device includes the photoelectric conversion element of the present invention and a converter. The converter can be a converter for converting a DC voltage into an AC voltage. The photoelectric conversion device may include a power storage unit connected to the photoelectric conversion element. As long as the power storage unit can store electricity, the power storage unit is not limited. Examples thereof include secondary batteries using lithium ions, etc., all-solid-state batteries, and electric double layer capacitors.

[0098] [Application example]

[0099] [Moving body]

[0100] The moving body of the present invention preferably includes the above-mentioned photoelectric conversion element. Figure 3It is a perspective view schematically showing an example of an application of a moving body including the photoelectric conversion element of the present invention. The moving body 30 includes the photoelectric conversion element 31 of the present invention and a body 32 including the photoelectric conversion element 31. The photoelectric conversion element 31 is disposed at a position on the body 32 where external light can be received. When the moving body 30 is an automobile, the photoelectric conversion element 31 can be disposed on the roof. The electric energy obtained by the photoelectric conversion element 31 can be used as the power of the moving body 30 or the power of any other electrical device. The electric energy generated by the power of the moving body 30 can be used for the power of the photoelectric conversion element 31. When the moving body 30 is an automobile, the frictional energy generated by the brake can be converted into electric energy for controlling the photoelectric conversion element 31.

[0101] The moving body 30 can be, for example, an automobile, a ship, an aircraft or a drone. The structure of the body 32 of the moving body 30 is not particularly limited, but it is preferably formed of a material with high strength.

[0102] [Building materials]

[0103] The building materials of the present invention preferably include the above-mentioned photoelectric conversion element. Figure 4 It is a perspective view schematically showing another example of an application of building materials including the photoelectric conversion element of the present invention. The building material 40 can be the roof of a building. The building material 40 in the application example includes the photoelectric conversion element 41 of the present invention, a protection member 42 for protecting the photoelectric conversion element 41, a heat dissipation member 43, and exteriors 44a and 44b.

[0104] The building material 40 of the present invention can include a heat dissipation member 43 having a higher thermal conductivity than that of the photoelectric conversion element 41. When the building material 40 is used for a roof or the like, the temperature of the photoelectric conversion element 41 may rise due to sunlight, so the photoelectric conversion efficiency may decrease. By using the heat dissipation member 43, the decrease in the photoelectric conversion efficiency can be reduced. Examples of the heat dissipation member 43 include metals, alloys, liquid metals, and liquid resins.

[0105] In addition, the building material 40 of the present invention can include exteriors 44a and 44b. The exteriors 44a and 44b can show different colors or the same color. The exteriors 44a and 44b can be formed of the same member or can be formed of different members. A coating or a transparent substrate can be used as the exterior. An exterior having small light absorption and high heat shielding properties is preferred.

[0106] [Examples]

[0107] The present invention will be described in more detail below by way of examples, but the present invention is not limited to these examples. In addition, in the following description, unless otherwise specifically stated, the term "part" means "part by mass".

[0108] [Manufacture of phthalocyanine compound particles]

[0109] [Manufacture of Particle 1]

[0110] Step (1)

[0111] Under a flowing nitrogen atmosphere, 5.46 parts of phthalonitrile and 45 parts of α-chloronaphthalene were charged into a reaction kettle. Thereafter, the mixture was heated to raise its temperature to 30 °C and then maintained at this temperature. Next, 3.75 parts of gallium trichloride were charged into the mixture at this temperature (30 °C). The water concentration of the mixed solution at the time of charging was 150 ppm. Thereafter, the temperature of the mixed solution was raised to 200 °C. Next, under a flowing nitrogen atmosphere, the mixed solution was reacted at a temperature of 200 °C for 4.5 hours and then cooled. When the temperature of the product reached 150 °C, the product was filtered. The obtained filter residue was dispersed and washed with N,N-dimethylformamide at a temperature of 140 °C for 2 hours and then filtered. The obtained filter residue was washed with methanol and then dried to obtain gallium chloro-phthalocyanine particles with a yield of 71%.

[0112] Step (2)

[0113] 4.65 parts of gallium chloro-phthalocyanine particles were dissolved in 139.5 parts of concentrated sulfuric acid at a temperature of 10 °C, and the solution was dropped into 620 parts of ice water under stirring to cause the particles to reprecipitate, and then filtered with a pressure filter under reduced pressure. At this time, No. 5C (manufactured by Advantec Toyo Kaisha, Ltd.) was used as the filter. The obtained wet filter cake (filter residue) was dispersed and washed with 2% ammonia water for 30 minutes and then filtered with a pressure filter. Next, the obtained wet filter cake (filter residue) was dispersed and washed with ion-exchanged water and then repeatedly filtered with a pressure filter 3 times. Finally, the filter residue was freeze-dried to obtain hydroxygallium phthalocyanine particles (hydrated hydroxygallium phthalocyanine particles) with a solid content of 23% by mass and a yield of 71%. The hydroxygallium phthalocyanine particles were dried with a super-dryer (trade name: HD-06R, frequency (oscillation frequency): 2,455 MHz ± 15 MHz, manufactured by Biocon (Japan) Ltd.). Thus, hydroxygallium phthalocyanine particles (crystals) with a water content of 1.0% by mass or less were obtained.

[0114] Step (3)

[0115] Disperse 5 parts of hydroxygallium phthalocyanine (HOGaPc) particles using a sand mill (K-800, manufactured by Igarashi Machine Production Co., Ltd. (now AIMEX Co., Ltd.), disk diameter: 70 mm, number of disks: 5) in which 5 parts of N,N-dimethylformamide (DMF) used as a solvent and 5 parts of glass beads have been added for 6 hours. Filter and dry the resulting product to obtain Particle 1.

[0116] (Example 1)

[0117] [Formation of electron transport layer]

[0118] Clean a glass substrate with indium tin oxide (ITO), and coat tin(II) oxide adjusted to 3% by mass thereon by spin coating. Thereafter, heat the resulting product at 150 °C for 30 minutes to form an electron transport layer in the form of a film with a thickness of 100 nm.

[0119] [Formation of photoelectric conversion layer]

[0120] Dissolve 4 g of lead iodide and 1.4 g of methylammonium iodide in 4.5 g of N,N-dimethylformamide used as a solvent, and stir the solution at 60 °C for 24 hours to prepare a coating solution for the photoelectric conversion layer. Coat the coating solution onto the electron transport layer by spin coating to form a photoelectric conversion layer with a thickness of 500 nm formed of MAPbI 3

[0121] [Formation of charge transport layer]

[0122] Disperse 0.05 g of Particle 1 using a sand mill (K-800, manufactured by Igarashi Machine Production Co., Ltd. (now AIMEX Co., Ltd.), disk diameter: 70 mm, number of disks: 5) in which 4.95 g of 2-propanol used as a solvent, 0.0001 g of phenol used as an aromatic ring compound having a hydroxyl group, and 11 g of glass beads have been added for 6 hours to prepare a charge transport layer solution. Coat the charge transport layer solution onto the photoelectric conversion layer by spin coating to form a charge transport layer with a thickness of 100 nm.

[0123] [Introduction of hole transport layer]

[0124] ​Dissolve 180 mg of spiro-OMeTAD, which is used as a hole-transporting compound, in 1 mL of chlorobenzene. Add 37.5 μL of an acetonitrile solution obtained by dissolving 170 mg of lithium bis(trifluoromethanesulfonyl)imide in 1 ml of acetonitrile and 17.5 μL of tert-butylpyridine (TBP) to the chlorobenzene solution, and mix the contents to prepare a solution of the hole-transporting compound. Coat the solution onto the charge-transporting layer by spin coating to form a hole-transporting layer with a thickness of 200 nm.

[0125] [Formation of the first electrode]

[0126] Form a gold electrode with a thickness of 80 nm and an area of 0.09 cm 2 on the hole-transporting layer by vacuum vapor deposition. Thus, a photoelectric conversion element is obtained.

[0127] (Examples 2 to 5)

[0128] A photoelectric conversion element is obtained in the same manner as in Example 1, except that 0.00025 g, 0.005 g, 0.025 g, and 0.04 g of an aromatic ring compound having a hydroxyl group are used in Example 2, Example 3, Example 4, and Example 5, respectively.

[0129] (Examples 6 to 8)

[0130] A photoelectric conversion element is obtained in the same manner as in Example 1, except that the aromatic ring compound having a hydroxyl group is changed to 1-naphthol, and 0.0001 g, 0.00025 g, and 0.025 g of it are used in Example 6, Example 7, and Example 8, respectively.

[0131] (Examples 9 to 12)

[0132] A photoelectric conversion element is obtained in the same manner as in Example 1, except that the aromatic ring compound having a hydroxyl group is changed to an aromatic ring compound represented by formula [C-1], and 0.0001 g, 0.00025 g, 0.0025 g, and 0.005 g of it are used in Example 9, Example 10, Example 11, and Example 12, respectively.

[0133] (Example 13)

[0134] A photoelectric conversion element is obtained in the same manner as in Example 1, except that the aromatic ring compound having a hydroxyl group is changed to an aromatic ring compound represented by formula [C-1], and 0.005 g of it is used; and the hole-transporting compound of the hole-transporting layer is changed to PTAA (CAS: 1333317-99-9, manufactured by Luminescence Technology Corp.).

[0135] (Example 14)

[0136] Except that the aromatic ring compound having a hydroxyl group is changed to the aromatic ring compound represented by the formula [C-1], and 0.005 g thereof is used; and the crystal having a perovskite structure is changed to Cs 5 (MA 0.17 FA 0.83 ) 95 Pb(I 0.83 Br 0.17 ) 3 A photoelectric conversion element is obtained in the same manner as in Example 1, except for the above changes.

[0137] (Examples 15 to 17)

[0138] A photoelectric conversion element is obtained in the same manner as in Example 1, except that the aromatic ring compound having a hydroxyl group is changed to the aromatic ring compound represented by the formula [C-1], and 0.015 g, 0.025 g, and 0.04 g thereof are used in Example 15, Example 16, and Example 17, respectively.

[0139] (Example 18)

[0140] A photoelectric conversion element is obtained in the same manner as in Example 1, except that the aromatic ring compound having a hydroxyl group is changed to the aromatic ring compound represented by the formula [C-9], and 0.005 g thereof is used.

[0141] (Example 19)

[0142] A photoelectric conversion element is obtained in the same manner as in Example 1, except that 0.005 g of the product obtained by mixing the aromatic ring compound represented by the formula [C-1] and the aromatic ring compound represented by the formula [C-2] in a mass ratio of 1:1 is used as the aromatic ring compound having a hydroxyl group.

[0143] (Examples 20 to 22)

[0144] A photoelectric conversion element is obtained in the same manner as in Example 1, except that the aromatic ring compound having a hydroxyl group is changed to the product obtained by mixing the aromatic ring compounds represented by the formulas [C-1] to [C-4] respectively, and 0.0001 g, 0.00025 g, and 0.005 g thereof are used in Example 20, Example 21, and Example 22, respectively. The mass ratio is set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0145] (Example 23)

[0146] Except for changing the aromatic ring compound having a hydroxyl group to a product obtained by mixing the aromatic ring compounds represented by Formulas [C-1] to [C-4] respectively, and using 0.005 g thereof; and changing the crystal having a perovskite structure to Sr 2 Nb 2 O 7 other than that, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0147] (Example 24)

[0148] Except for changing the aromatic ring compound having a hydroxyl group to a product obtained by mixing the aromatic ring compounds represented by Formulas [C-1] to [C-4] respectively, and using 0.005 g thereof; and not forming a hole transport layer other than that, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0149] (Example 25)

[0150] Except for changing the aromatic ring compound having a hydroxyl group to a product obtained by mixing the aromatic ring compounds represented by Formulas [C-1] to [C-4] respectively, and using 0.005 g thereof; and changing the film formation order of the hole transport layer and the charge transport layer to the reverse so that the hole transport layer is in contact with the photoelectric conversion layer other than that, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0151] (Examples 26 and 27)

[0152] Except for changing the aromatic ring compound having a hydroxyl group to a product obtained by mixing the aromatic ring compounds represented by Formulas [C-1] to [C-4] respectively, and using 0.025 g and 0.04 g thereof in Example 26 and Example 27 respectively other than that, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0153] (Example 28)

[0154] Except that the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by the following formula [A-1] (CAS: 490-46-0, manufactured by FUJIFILM Corporation) and the aromatic ring compound represented by the following formula [A-2] (CAS: 970-73-0, manufactured by FUJIFILM Corporation), and 0.005 g thereof was used, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [A-1]:[A-2]=1:1.

[0155] [Chemical formula 12]

[0156]

[0157] (Example 29)

[0158] Except that 0.005 g of a product obtained by mixing the aromatic ring compound represented by formula [C-5] and the aromatic ring compound represented by formula [C-6] in a mass ratio of 1:1 was used as the aromatic ring compound having a hydroxyl group, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0159] (Example 30)

[0160] Except that 0.005 g of a product obtained by mixing the aromatic ring compound represented by formula [C-7] and the aromatic ring compound represented by formula [C-8] in a mass ratio of 1:1 was used as the aromatic ring compound having a hydroxyl group, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0161] (Examples 31 to 33)

[0162] Except that the phthalocyanine compound was changed to copper phthalocyanine (CuPc); and 0.0001 g, 0.005 g, and 0.04 g of the aromatic ring compound having a hydroxyl group were used in Example 31, Example 32, and Example 33, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0163] (Examples 34 and 35)

[0164] Except that the phthalocyanine compound was changed to copper phthalocyanine; and the aromatic ring compound having a hydroxyl group was changed to 1-naphthol, and 0.00025 g and 0.025 g thereof were used in Example 34 and Example 35, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0165] (Examples 36 to 38)

[0166] Except that the phthalocyanine compound was changed to copper phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by the formula [C-1], and 0.0001 g, 0.0025 g, and 0.005 g thereof were used in Example 36, Example 37, and Example 38, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0167] (Example 39)

[0168] Except that the phthalocyanine compound was changed to copper phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by the formula [C-1], and 0.005 g thereof was used; and the hole transporting compound was changed to PTAA, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0169] (Example 40)

[0170] Except that the phthalocyanine compound was changed to copper phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by the formula [C-1], and 0.005 g thereof was used; and the crystal having a perovskite structure was changed to Cs 5 (MA 0.17 FA 0.83 ) 95 Pb(I 0.83 Br 0.17 ) 3 other than that, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0171] (Examples 41 and 42)

[0172] Except that the phthalocyanine compound was changed to copper phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by the formula [C-1], and 0.015 g and 0.04 g thereof were used in Example 41 and Example 42, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0173] (Example 43)

[0174] Except that the phthalocyanine compound was changed to copper phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by the formula [C-9], and 0.005 g thereof was used, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0175] (Examples 44 and 45)

[0176] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to copper phthalocyanine; and the aromatic ring compound having a hydroxyl group was changed to a product obtained by mixing the aromatic ring compounds represented by Formulas [C-1] to [C-4] respectively, and 0.00025 g and 0.025 g thereof were used in Example 44 and Example 45 respectively. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0177] (Examples 46 to 48)

[0178] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to zinc phthalocyanine (ZnPc); and 0.0001 g, 0.005 g and 0.04 g of the aromatic ring compound having a hydroxyl group were used in Example 46, Example 47 and Example 48 respectively.

[0179] (Examples 49 and 50)

[0180] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to zinc phthalocyanine; and the aromatic ring compound having a hydroxyl group was changed to 1-naphthol, and 0.00025 g and 0.025 g thereof were used in Example 49 and Example 50 respectively.

[0181] (Examples 51 to 53)

[0182] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to zinc phthalocyanine; and the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.0001 g, 0.0025 g and 0.005 g thereof were used in Example 51, Example 52 and Example 53 respectively.

[0183] (Example 54)

[0184] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to zinc phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.005 g thereof was used; and the hole transporting compound in the hole transporting layer was changed to PTAA.

[0185] (Example 55)

[0186] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to zinc phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.005 g thereof was used; and the crystal having a perovskite structure was changed to Cs 5 (MA 0.17FA 0.83 ) 95 Pb(I 0.83 Br 0.17 ) 3 Except for the above, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0187] (Examples 56 and 57)

[0188] Except for changing the phthalocyanine compound to zinc phthalocyanine; and changing the aromatic ring compound having a hydroxyl group to the aromatic ring compound represented by the formula [C-1], and using 0.015 g and 0.04 g thereof in Examples 56 and 57, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0189] (Example 58)

[0190] Except for changing the phthalocyanine compound to zinc phthalocyanine; and changing the aromatic ring compound having a hydroxyl group to the aromatic ring compound represented by the formula [C-9], and using 0.005 g thereof, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0191] (Examples 59 and 60)

[0192] Except for changing the phthalocyanine compound to zinc phthalocyanine; and changing the aromatic ring compound having a hydroxyl group to the product obtained by mixing the aromatic ring compounds represented by the formulas [C-1] to [C-4] respectively, and using 0.00025 g and 0.025 g thereof in Examples 59 and 60, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0193] (Examples 61 to 63)

[0194] Except for changing the phthalocyanine compound to titanyl phthalocyanine (TiPc); and using 0.0001 g, 0.005 g and 0.04 g of the aromatic ring compound having a hydroxyl group in Examples 61, 62 and 63, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0195] (Examples 64 and 65)

[0196] Except for changing the phthalocyanine compound to titanyl phthalocyanine; and changing the aromatic ring compound having a hydroxyl group to 1-naphthol, and using 0.00025 g and 0.025 g thereof in Examples 64 and 65, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0197] (Examples 66 to 68)

[0198] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to titanium oxyphthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.0001 g, 0.0025 g, and 0.005 g thereof were used in Example 66, Example 67, and Example 68, respectively.

[0199] (Example 69)

[0200] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to titanium oxyphthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.005 g thereof was used; and the hole transporting compound in the hole transporting layer was changed to PTAA.

[0201] (Example 70)

[0202] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to titanium oxyphthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.005 g thereof was used; and the crystal having a perovskite structure was changed to Cs 5 (MA 0.17 FA 0.83 ) 95 Pb(I 0.83 Br 0.17 ) 3 other than that.

[0203] (Examples 71 and 72)

[0204] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to titanium oxyphthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.015 g and 0.04 g thereof were used in Example 71 and Example 72, respectively.

[0205] (Example 73)

[0206] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to titanium oxyphthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-9], and 0.005 g thereof was used.

[0207] (Examples 74 and 75)

[0208] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to titanium oxyphthalocyanine; and the aromatic ring compound having a hydroxyl group was changed to a product obtained by mixing the aromatic ring compounds represented by Formulas [C-1] to [C-4] respectively, and 0.00025 g and 0.025 g thereof were used in Example 74 and Example 75 respectively. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0209] (Examples 76 to 78)

[0210] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to gallium chloride phthalocyanine (ClGaPc); and 0.0001 g, 0.005 g and 0.04 g of the aromatic ring compound having a hydroxyl group were used in Example 76, Example 77 and Example 78 respectively.

[0211] (Examples 79 and 80)

[0212] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to gallium chloride phthalocyanine; and the aromatic ring compound having a hydroxyl group was changed to 1-naphthol, and 0.00025 g and 0.025 g thereof were used in Example 79 and Example 80 respectively.

[0213] (Examples 81 and 82)

[0214] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to gallium chloride phthalocyanine; and the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.0001 g and 0.005 g thereof were used in Example 81 and Example 82 respectively.

[0215] (Example 83)

[0216] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to gallium chloride phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.005 g thereof was used; and the hole transporting compound in the hole transporting layer was changed to PTAA.

[0217] (Example 84)

[0218] A photoelectric conversion element was obtained in the same manner as in Example 1, except that the phthalocyanine compound was changed to gallium chloride phthalocyanine; the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by Formula [C-1], and 0.005 g thereof was used; and the crystal having a perovskite structure was changed to Cs 5 (MA 0.17 FA0.83 ) 95 Pb(I 0.83 Br 0.17 ) 3 Except for the above, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0219] (Example 85)

[0220] Except for changing the phthalocyanine compound to gallium chloro-phthalocyanine; and changing the aromatic ring compound having a hydroxyl group to the aromatic ring compound represented by Formula [C-1], and using 0.04 g thereof, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0221] (Example 86)

[0222] Except for changing the phthalocyanine compound to gallium chloro-phthalocyanine; and changing the aromatic ring compound having a hydroxyl group to the aromatic ring compound represented by Formula [C-9], and using 0.005 g thereof, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0223] (Examples 87 and 88)

[0224] Except for changing the phthalocyanine compound to gallium chloro-phthalocyanine; and changing the aromatic ring compound having a hydroxyl group to the product obtained by mixing the aromatic ring compounds represented by Formulas [C-1] to [C-4] respectively, and using 0.00025 g and 0.025 g thereof in Example 87 and Example 88 respectively, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4]=1:1:1:1.

[0225] (Example 89)

[0226] Except for changing the phthalocyanine compound to metal-free phthalocyanine (Pc); and changing the aromatic ring compound having a hydroxyl group to the product obtained by mixing the aromatic ring compounds represented by Formulas [C-1] to [C-4] respectively, and using 0.005 g thereof, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4]=1:1:1:1.

[0227] (Example 90)

[0228] Except that the phthalocyanine compound was changed to gallium phthalocyanine represented by the following formula [F-1]; and the aromatic ring compound having a hydroxyl group was changed to a product obtained by mixing the aromatic ring compounds represented by formulas [C-1] to [C-4] respectively, and 0.005 g thereof was used, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0229] [Chemical formula 13]

[0230]

[0231] (Comparative Example 1)

[0232] Except that the phthalocyanine compound was changed to zinc phthalocyanine; and the aromatic ring compound having a hydroxyl group was not used, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0233] (Comparative Example 2)

[0234] Except that the phthalocyanine compound was changed to titanium oxyphthalocyanine; and the aromatic ring compound having a hydroxyl group was not used, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0235] (Comparative Example 3)

[0236] Except that the phthalocyanine compound was not used, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0237] (Comparative Example 4)

[0238] Except that the phthalocyanine compound was not used; and the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by formula [C-1], a photoelectric conversion element was obtained in the same manner as in Example 1.

[0239] (Comparative Example 5)

[0240] Except that the phthalocyanine compound was not used; and the aromatic ring compound having a hydroxyl group was changed to a product obtained by mixing the aromatic ring compounds represented by formulas [C-1] to [C-4] respectively, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0241] (Examples 91 to 93)

[0242] Except that the phthalocyanine compound was changed to spiro-OMeTAD used as a hole transporting compound; and the aromatic ring compound having a hydroxyl group was changed to the aromatic ring compound represented by the formula [C-1], and 0.00025 g, 0.005 g, and 0.025 g thereof were used in Example 91, Example 92, and Example 93, respectively, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0243] (Example 94)

[0244] Except that the phthalocyanine compound was changed to spiro-OMeTAD used as a hole transporting compound; and the aromatic ring compound having a hydroxyl group was changed to a product obtained by mixing the aromatic ring compounds represented by the formulas [C-1] to [C-4] respectively, and 0.005 g thereof was used, a photoelectric conversion element was obtained in the same manner as in Example 1. The mass ratio was set to [C-1]:[C-2]:[C-3]:[C-4] = 1:1:1:1.

[0245] (Comparative Example 6)

[0246] Except that the phthalocyanine compound was changed to spiro-OMeTAD used as a hole transporting compound, and 0.0001 g thereof was used, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0247] (Comparative Example 7)

[0248] Except that the phthalocyanine compound was changed to spiro-OMeTAD used as a hole transporting compound, and 0.04 g thereof was used, a photoelectric conversion element was obtained in the same manner as in Example 1.

[0249] [Evaluation]

[0250] The following evaluations were performed on the photoelectric conversion elements obtained in each example and comparative example.

[0251] (Power generation efficiency evaluation)

[0252] A power supply (manufactured by Keithley Instruments, model 236) was connected between the electrodes of the photoelectric conversion element, and a solar simulator (manufactured by Yamashita Denso Corporation) was used at 100 mW / cm 2Constant light is applied at a certain intensity, and the generated current and voltage are measured. Thus, the photoelectric conversion efficiency is evaluated. The degradation evaluation is carried out by continuously applying light of 2,000 Lx and measuring the photoelectric conversion efficiency after 30 days. The stability of the device is evaluated by the attenuation rate of the conversion efficiency after 30 days relative to the initial conversion efficiency (degradation rate after 30 days). The results are shown in Tables 1 to 4. In each table, the term "usage amount" in the "aromatic ring compound having a hydroxyl group" represents the usage amount (parts by mass) of the aromatic ring compound when the usage amount of the phthalocyanine compound is set to 100 parts by mass.

[0253] [Table 1]

[0254] Table 1

[0255]

[0256] [Table 2]

[0257] Table 2

[0258]

[0259] [Table 3]

[0260] Table 3

[0261]

[0262] [Table 4]

[0263] Table 4

[0264]

[0265] The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the gist and scope of the present invention. To disclose the scope of the present invention, the claims are appended.

[0266] This application claims priority based on Japanese Patent Application No. 2022-167637 filed on October 19, 2022, and Japanese Patent Application No. 2023-158475 filed on September 22, 2023, the entire contents of which are incorporated herein by reference.

[0267] [Explanation of Reference Numerals]

[0268] 1 Photoelectric conversion element

[0269] 2 Substrate

[0270] 3 Second electrode

[0271] 4 Electron transport layer

[0272] 5 Photoelectric conversion layer

[0273] 6 Hole transport layer

[0274] 7 First electrode

[0275] 8 Charge transport layer

Claims

1. A photoelectric conversion element, which comprises: a first electrode; a second electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode and containing a crystal having a perovskite structure, wherein the photoelectric conversion element includes a charge transport layer between the photoelectric conversion layer and the first electrode, and the charge transport layer contains a phthalocyanine compound and an aromatic ring compound having a hydroxyl group different from the phthalocyanine compound.

2. The photoelectric conversion element according to claim 1, wherein the number of hydroxyl groups in the aromatic ring compound is greater than the number of hydroxyl groups in the phthalocyanine compound.

3. The photoelectric conversion element according to claim 1 or 2, wherein the number of hydroxyl groups in the aromatic ring compound is 3 or more.

4. The photoelectric conversion element according to claim 1 or 2, wherein the number of hydroxyl groups in the aromatic ring compound is 4 or more.

5. The photoelectric conversion element according to any one of claims 1 to 4, wherein the charge transport layer contains a plurality of the aromatic ring compounds.

6. The photoelectric conversion element according to any one of claims 1 to 5, wherein the aromatic ring compound is a compound represented by the following general formula [1]: [Chemical formula 1] In the general formula [1], R 1 to R 4 each independently represents, in each repeating unit and independently for the "n" repeating units, hydrogen, a halogen atom, a hydroxyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted organic group, "n" represents an integer from 3 to 20, and the compound has at least one hydroxyl group in its molecule.

7. The photoelectric conversion element according to claim 6, wherein in the general formula [1], "n" represents 4 or 8.

8. The photoelectric conversion element according to claim 6 or 7, wherein in the general formula [1], R 1 independently represents a halogen atom or a hydroxyl group for each of the "n" repeating units, and at least one R 1 represents a hydroxyl group, and R 3 independently represents a nitrophenylazo group or a dinitrophenylazo group for each of the "n" repeating units.

9. The photoelectric conversion element according to any one of claims 1 to 8, wherein the charge transport layer contains at least one compound selected from the group consisting of the following as the aromatic ring compound: a compound represented by the following formula [C-1]; a compound represented by the following formula [C-2]; a compound represented by the following formula [C-3]; and a compound represented by the following formula [C-4]: [Chemical formula 2] [Chemical formula 3] [Chemical formula 4] [Chemical formula 5] 10. The photoelectric conversion element according to claim 9, wherein the charge transport layer contains the compound represented by the formula [C-1], the compound represented by the formula [C-2], the compound represented by the formula [C-3], and the compound represented by the formula [C-4] as the aromatic ring compound.

11. The photoelectric conversion element according to any one of claims 1 to 10, wherein the molecular weight of the aromatic ring compound is 10,000 or less.

12. The photoelectric conversion element according to any one of claims 1 to 11, wherein the charge transport layer is in contact with the photoelectric conversion layer.

13. The photoelectric conversion element according to any one of claims 1 to 12, wherein the phthalocyanine compound is a metal phthalocyanine compound.

14. The photoelectric conversion element according to any one of claims 1 to 13, wherein the phthalocyanine compound is a gallium phthalocyanine compound.

15. The photoelectric conversion element according to any one of claims 1 to 13, wherein the phthalocyanine compound is a hydroxy gallium phthalocyanine compound.

16. The photoelectric conversion element according to any one of claims 1 to 15, wherein the crystal having a perovskite structure is a crystal of a compound represented by the following general formula [2]: R-M-X 3 [2] In the general formula [2], R represents either or both of an organic molecule and an inorganic atom, M represents a metal atom, and X represents a halogen atom or a chalcogen atom.

17. The photoelectric conversion element according to any one of claims 1 to 16, wherein when the content of the phthalocyanine compound is set to 100 parts by mass, the content of the aromatic ring compound in the charge transport layer is 0.5 parts by mass or more and 50 parts by mass or less in terms of parts by mass.

18. The photoelectric conversion element according to any one of claims 1 to 17, wherein the photoelectric conversion element includes a hole transport layer between the charge transport layer and the first electrode.

19. The photoelectric conversion element according to claim 18, wherein the hole transport layer contains spiro-OMeTAD as a hole transporting compound.

20. A photoelectric conversion element, which comprises: a first electrode; a second electrode; and a photoelectric conversion layer disposed between the first electrode and the second electrode and containing a crystal having a perovskite structure, wherein the photoelectric conversion element includes a charge transport layer between the photoelectric conversion layer and the first electrode, and the charge transport layer contains a hole transporting compound and an aromatic ring compound represented by the following general formula [1]: [Chemical formula 6] In the general formula [1], R 1 to R 4 each independently represents, in each repeating unit and independently for the "n" repeating units, hydrogen, a halogen atom, a hydroxyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted organic group, "n" represents an integer from 3 to 20, and the compound has at least one hydroxyl group in its molecule.

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