Chalcogenide perovskite and chalcogenide perovskite production method using liquid phase synthesis

Abstract

Provided is chalcogenide perovskite wherein: the crystallite size τ1 is less than 40 nm, as calculated using the Scherrer equation on the basis of a diffraction peak having the maximum peak height in an X-ray diffraction spectrum obtained by X-ray diffraction measurement; and, in an image area captured by a microscope, the ratio of the total area occupied by particles having a particle diameter of 10 μm or more, as measured by microscope, with respect to the total area occupied by particles present in the captured image area is 10% or less.

Description

Chalcogenide perovskite and method for producing chalcogenide perovskite by liquid phase synthesis

[0001] The present invention relates to chalcogenide perovskite and a method for producing the same, a composition, a powder, a sintered body, a thin film and a method for producing the same, a method for producing a sheet, a luminescent material, a light-emitting device, an image sensor, a photoelectric conversion device, and a bioluminescent marker.

[0002] In recent years, quantum dots (semiconductor nanocrystalline particles) have attracted attention as next-generation light-emitting device materials because they exhibit physical properties different from bulk materials in terms of light absorption and light emission characteristics, such as changes in light absorption wavelength (band gap energy) depending on particle size. While cadmium-containing materials such as CdS, CdSe, and CdTe are known as quantum dots, environmental concerns have led to the development of materials that do not contain cadmium or other harmful metals.

[0003] Chalcogenide perovskites having a perovskite-type crystal structure have been investigated as materials that do not contain harmful metals (see, for example, Non-Patent Documents 1 and 2 and Patent Document 1). For example, Non-Patent Documents 1 and 2 disclose chalcogenide perovskites synthesized by solid-phase synthesis. While the synthesis of fine particles by solid-phase synthesis is a widely known technique, it suffers from problems such as the tendency for impurities to be mixed in during the synthesis process and significant particle aggregation. For this reason, particles obtained by solid-phase synthesis are difficult to miniaturize and difficult to control in terms of particle size and shape, resulting in a wide particle size distribution. Furthermore, solid-phase synthesis generally tends to produce micron-sized particles. Further pulverization of these particles into nanoparticles results in numerous defects on the particle surface and interior, resulting in a significant decrease in fluorescence intensity. In contrast, liquid-phase synthesis has attracted attention as a method for synthesizing fine particles that can solve the aforementioned problems associated with solid-phase synthesis. As an example of a liquid phase synthesis method, Patent Document 1 discloses a method for producing semiconductor nanocrystalline particles, in which a first metal precursor, a second metal precursor, and a chalcogen precursor are heated at a temperature of about 100°C to 400°C in the presence of an organic solvent and a ligand compound.

[0004] US2019 / 0225883

[0005] VKRavi et al., “Colloidal BaZrS3 chalcogenide perovskite nanocrystals for thin film device fabrication”, The Royal Society of Chemistry, Nanoscale, 2021, Vol.13, p.1616-1623S. Filippone et al., “High densification of BaZrS3 powder inspired by the cold-sintering process”, Journal of Materials Research, 2021, Vol. 36, p.4404-4412

[0006] The present inventors prepared chalcogenide perovskite based on the liquid-phase synthesis method of chalcogenide perovskite disclosed in Patent Document 1. When the crystal structure was examined, it was found to be different from the crystal structure obtained by solid-phase synthesis based on the JCPDS card. An object of the present invention is to provide a chalcogenide perovskite that is easy to obtain with desired optical absorption or luminescence characteristics. Another object of the present invention is to provide a manufacturing method that allows chalcogenide perovskite to be obtained by liquid-phase synthesis, with a crystal structure similar to that obtained by solid-phase synthesis.

[0007] According to the present invention, the following chalcogenide perovskite and a method for producing the same are provided. 1. A chalcogenide perovskite in which, in an X-ray diffraction spectrum obtained by X-ray diffraction measurement, the crystallite size τ1 calculated by Scherrer equation based on the diffraction peak with the maximum peak height is less than 40 nm, and in which, in an image area captured by a microscope, the ratio of the total area occupied by particles having a particle size of 10 μm or more as measured by microscopy to the total area occupied by particles present in the captured image area is 10% or less. 2. The chalcogenide perovskite according to 1, in which the crystallite size τ2 calculated by Williamson-Hall equation based on the X-ray diffraction spectrum obtained by X-ray diffraction measurement is 34.5 nm or less. 3. The chalcogenide perovskite according to 2, in which the crystallite size τ2 is 30 nm or less. 4. The chalcogenide perovskite according to any one of 1 to 3, in which the crystallite size τ1 is less than 17.5 nm. 5. 5. The chalcogenide perovskite according to any one of 1 to 4, having a composition represented by the following formula (101) or (102): ABCh ３ ...(101) A' ２ A ｎ－１ B ｎ Ch ３ｎ＋１...(102) (In formulas (101) and (102), A and A' are each Sr, Ba or a combination thereof, B is Zr, Hf or a combination thereof, and Ch is S, Se, Te or a combination thereof. In formula (102), n is an integer of 1 or more and 10 or less. In formula (102), A and A' may be the same as or different from each other. The chalcogenide perovskite may be a solid solution in which part or all of A, A', B and Ch in the composition represented by formula (101) or (102) are substituted with other elements.) 6. A chalcogenide perovskite according to any one of 1 to 5, wherein particles of the chalcogenide perovskite are surface-modified with a ligand. 7. A composition in which the chalcogenide perovskite according to any one of 1 to 6 is dispersed in a dispersion medium. 8. The composition according to claim 7, which is a dispersion using a liquid dispersion medium as the dispersion medium. 9. The composition according to claim 8, wherein the liquid dispersion medium is at least one selected from the group consisting of water, esters, ketones, ethers, alcohols, glycol ethers, organic solvents having an amide group, organic solvents having a nitrile group, organic solvents having a carbonate group, organic solvents having a halogenated hydrocarbon group, organic solvents having a hydrocarbon group, and dimethyl sulfoxide. 10. The composition according to claim 7, which is a sheet using a solid dispersion medium as the dispersion medium. 11. The composition according to claim 10, wherein the solid dispersion medium is at least one selected from the group consisting of polyvinyl butyral, polyvinyl acetate, and silicone and its derivatives. 12. A powder comprising the chalcogenide perovskite according to any one of claims 1 to 6. 13. The powder according to claim 12, wherein primary particles or secondary particles of the chalcogenide perovskite are surface-modified with a ligand. 14. A sintered body obtained by sintering the powder according to claim 12 or 13. 15. A thin film comprising the chalcogenide perovskite according to any one of 1 to 6. 16. A method for producing a thin film according to 15, in which the dispersion according to 8 or 9 is formed into a film by a coating method, a spraying method, a doctor blade method, or an inkjet method. 17. A method for producing a thin film according to 15, in which the powder of the chalcogenide perovskite according to 12 or 13 is formed into a film by a sputtering method or a vacuum deposition method.18. A method for producing the sheet according to 10, wherein the dispersion according to 8 or 9 is applied to a sheet and then dried. 19. A luminescent material comprising the chalcogenide perovskite according to any one of 1 to 6. 20. A light-emitting device, an image sensor, a photoelectric conversion device, or a bioluminescent label comprising the chalcogenide perovskite according to any one of 1 to 6. 21. A method for producing a chalcogenide perovskite by reacting a complex having a first metal atom with a complex having a second metal atom in a liquid phase, wherein the complex having the first metal atom and the complex having the second metal atom have a ligand that does not contain an oxygen atom (O) or a halogen atom (X) as a coordinating atom. 22. The method according to 21, wherein the complex having the first metal atom and the complex having the second metal atom each have a ligand coordinated with an atom selected from the group consisting of a nitrogen atom (N), a sulfur atom (S), a selenium atom (Se), a tellurium atom (Te), a carbon atom (C), and a phosphorus atom (P). 23. The manufacturing method according to 21 or 22, wherein the metal atom of the complex having the first metal atom is at least one of Sr and Ba, and the metal atom of the complex having the second metal atom is at least one of Zr and Hf. 24. The manufacturing method according to 23, further comprising using at least one selected from Ti, Ca, and Mg for at least one of the metal atoms of the complex having the first metal atom and the metal atom of the complex having the second metal atom. 25. The manufacturing method according to any of 21 to 24, wherein the ligand is dithiocarbamate, xanthate, trithiocarbamate, dithioester, thiolate, sulfide, or a compound in which some or all of the sulfur atoms contained therein have been substituted with selenium atoms or tellurium atoms, an alkylamine, an arylamine, a trialkylsilylamine, a nitrogen-containing aromatic ring, an alkane, an unsaturated hydrocarbon ring, or a group derived from the unsaturated hydrocarbon ring, cyan, a trialkylphosphine, a triarylphosphine, or a diphosphine. 26. 26. The production method according to any one of 21 to 25, wherein the complex having the first metal atom and the complex having the second metal atom are a polynuclear complex that is a single compound.27. The manufacturing method according to 26, wherein the first metal atom and the second metal atom are bonded via a ligand coordinated by a sulfur atom, a selenium atom, or a tellurium atom. 28. The manufacturing method according to any one of 21 to 27, wherein the chalcogenide perovskite has a composition represented by the following formula (101) or (102): ABCh: ３ ...(101) A' ２ A ｎ－１ B ｎ Ch ３ｎ＋１...(102) (In formulas (101) and (102), A and A' are Sr, Ba, or a combination thereof, B is Zr, Hf, or a combination thereof, and Ch is S, Se, Te, or a combination thereof. In formula (102), n is an integer of 1 or more and 10 or less. In formula (102), A and A' may be the same as or different from each other. The chalcogenide perovskite may be a solid solution in which part or all of A, A', B, and Ch in the composition represented by formula (101) or (102) are substituted with other elements.) 29. The manufacturing method according to any one of 21 to 28, further comprising adding a chalcogen compound. 30. The manufacturing method according to any one of 21 to 29, further comprising adding an amine compound. 31. The manufacturing method according to any one of 21 to 30, wherein the temperature of the liquid phase is room temperature to 450°C. 32. The manufacturing method according to item 31, wherein the temperature of the liquid phase is set to 120°C to 360°C. 33. The manufacturing method according to any one of items 21 to 32, wherein the reaction is caused by adding a second raw material containing at least a raw material component not contained in the first raw material to a first raw material containing at least a solvent among raw material components including the complex having the first metal atom, the complex having the second metal atom, and a solvent. 34. The manufacturing method according to item 33, wherein the reaction is caused by adding the second raw material to the first raw material while at least one of the first raw material and the second raw material is preheated. 35. The manufacturing method according to item 33, wherein the reaction is caused by adding the second raw material to the first raw material and then heating the first raw material and the second raw material. 36. The manufacturing method according to item 35, wherein a dispersion in which the complex having the first metal atom and the complex having the second metal atom are dispersed in a dispersion medium is formed into a film by a coating method, a spray method, a doctor blade method, or an inkjet method, and the resulting coating film is heat-treated. 37. The manufacturing method according to any one of 21 to 32, wherein the complex having the first metal atom, the complex having the second metal atom, and at least one of a chalcogen compound and an amine compound are simultaneously mixed to cause the reaction.38. The manufacturing method according to 37, wherein the complex having the first metal atom, the complex having the second metal atom, and at least one of the chalcogen compound and the amine compound are circulated as independent flows, and the flows are simultaneously merged to cause the reaction to occur. 39. The manufacturing method according to 37 or 38, wherein at least one of the complex having the first metal atom, the complex having the second metal atom, and at least one of the chalcogen compound and the amine compound is preheated.

[0008] The present invention provides a chalcogenide perovskite that can easily achieve desired light absorption or emission characteristics, and also provides a production method that can obtain, by liquid phase synthesis, a chalcogenide perovskite having a crystal structure similar to that obtained by solid phase synthesis.

[0009] 1 is a diagram for explaining the relationship between crystallite size d10 and particle size d20. It is an X-ray diffraction spectrum of the chalcogenide perovskites produced in Examples 1 and 2. It is a diagram showing an approximation line created by the Williamson-Hall equation based on the diffraction peaks of the X-ray diffraction spectrum of Example 1. It is a diagram showing an approximation line created by the Williamson-Hall equation based on the diffraction peaks of the X-ray diffraction spectrum of Example 2. It is an SEM image (250,000 magnification) of the synthetic product obtained in Example 1. It is an SEM image (250,000 magnification) of the synthetic product obtained in Example 1. It is an STEM image (200,000 magnification) of the synthetic product obtained in Example 2. It is an STEM image (400,000 magnification) of the synthetic product obtained in Example 2.

[0010] The following describes embodiments of the invention. In this specification, "x to y" represents a numerical range of "greater than or equal to x and less than or equal to y." The upper and lower limits of the numerical ranges can be combined in any manner. Furthermore, among the individual embodiments of the aspects of the present invention described below, two or more embodiments that are not mutually contradictory can be combined, and an embodiment combining two or more embodiments is also an embodiment of the aspects of the present invention.

[0011] The chalcogenide perovskite according to one embodiment of the present invention has a crystallite size τ1 calculated by the Scherror formula of less than 40 nm, and is characterized in that, in an image captured by a microscope, the ratio of the total area occupied by particles having a particle diameter of 10 μm or more as measured by microscopy to the total area occupied by particles present within the captured image is 10% or less.

[0012] In the following description, "crystallite size" refers to the diameter d10 of a crystallite 10 calculated by the Scherrer equation or the Williamson-Hall equation described later, and the diameter d20 of a polycrystal 20 formed by the aggregation of multiple crystallites 10 is referred to as the "particle size" (see FIG. 1).

[0013] [Crystallite Size τ1] The crystallite size τ1 is a value calculated by the Scherrer equation represented by the following formula (a) based on the diffraction peak with the maximum peak height in the X-ray diffraction spectrum obtained by X-ray diffraction measurement: τ1=Kλ / βcosθ (a) θ: diffraction angle of the maximum peak [rad] β: half-width of the maximum peak [rad] K: shape factor λ: X-ray wavelength τ1: crystallite size X-ray diffraction measurement is performed by the method described in the examples.

[0014] Among the chalcogenide perovskites, for example, BaZrS, which will be described later, ３ As shown in the figure, the absorption spectrum and emission spectrum overlap in some wavelength ranges. In the wavelength range where the absorption spectrum and emission spectrum overlap, a portion of the light emitted from the particle is reabsorbed by nearby particles (self-reabsorption), resulting in a decrease in luminous efficiency. In the chalcogenide perovskite of this embodiment, the crystallite size τ1 is less than 40 nm, so the particle size is sufficiently small and self-reabsorption can be suppressed. Therefore, by applying the chalcogenide perovskite of this embodiment to a luminescent material, good luminous efficiency can be exhibited and excellent luminescent characteristics can be obtained.

[0015] Furthermore, when the particle diameter is reduced to the nanometer order, excited carriers (electrons and holes) are spatially confined, making it difficult for the carriers to disperse (carrier confinement effect). In the chalcogenide perovskite of this embodiment, the crystallite size τ1 is less than 40 nm, narrowing the range in which excited and confined carriers can move, thereby improving the recombination probability within the particles. Therefore, by applying the chalcogenide perovskite of this embodiment to a light-emitting material, the luminous efficiency can be improved and excellent luminous characteristics can be obtained. Furthermore, the carrier confinement effect can be enhanced by coating the chalcogenide perovskite of this embodiment with a material having a larger band gap than the chalcogenide perovskite (core-shell formation).

[0016] In general, as particle diameters become smaller, down to the nanometer order, the band structure (energy levels) of the particles becomes discrete, and the optical band gap value changes depending on the particle size (quantum size effect). In this case, the band gap value gradually increases as the particle diameter decreases, and when the particle diameter becomes smaller than a certain value, the band gap value increases rapidly. The chalcogenide perovskite of this embodiment can exhibit a higher band gap compared to those with larger particle sizes by having a crystallite size τ1 of less than 40 nm. This effect is particularly pronounced when the crystallite size τ1 is 30 nm or less. Therefore, by changing the crystallite size τ1 of the particles in the range of less than 40 nm, it is possible to change the band gap to a desired value. By controlling the band gap of the chalcogenide perovskite of this embodiment within an appropriate range and applying it to, for example, solar cells or light-emitting materials, it is possible to control the light absorption characteristics and light emission characteristics (emission wavelength) suitable for each use.

[0017] The crystallite size τ1 of the chalcogenide perovskite may be 35 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, less than 17.5 nm, 17 nm or less, 15 nm or less, 13 nm or less, 12 nm or less, 11.5 nm or less, or 10 nm or less. The lower limit of the crystallite size τ1 of the chalcogenide perovskite is not particularly limited, but may be, for example, 1 nm or more from the viewpoint of convenience in the manufacturing process.

[0018] In one embodiment, the chalcogenide perovskite has a maximum diffraction peak at 2θ = 25.0 ± 1° in the X-ray diffraction spectrum obtained by the X-ray diffraction measurement described above. The crystallite size τ1 calculated based on this diffraction peak (2θ = 25.0 ± 1°) is less than 40 nm. The crystallite size τ1 calculated based on the diffraction peak at 2θ = 25.0 ± 1° may be 35 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, less than 17.5 nm, 17 nm or less, 15 nm or less, 13 nm or less, 12 nm or less, 11.5 nm or less, or 10 nm or less, or may be 1 nm or more.

[0019] In the chalcogenide perovskite of this embodiment, the ratio of the total area occupied by particles having a particle diameter of 10 μm or more as measured by microscopy to the total area occupied by particles present within the captured image range in a microscope is 10% or less, thereby improving the uniformity of films or sheets formed using the chalcogenide perovskite of this embodiment. Furthermore, in the image range photographed with a microscope, the ratio of the total area occupied by particles having a particle diameter of 10 μm or more as measured by microscopy to the total area occupied by particles present within the captured image range is 10% or less, thereby suppressing nozzle clogging when applying ink made using the chalcogenide perovskite of this embodiment. Furthermore, in the image range photographed with a microscope, the ratio of the total area occupied by particles having a particle diameter of 10 μm or more as measured by microscopy to the total area occupied by particles present within the captured image range is 10% or less, thereby narrowing the emission spectral distribution of the quantum dots. Therefore, by applying the chalcogenide perovskite of this embodiment to a light-emitting material, color unevenness of emitted light is suppressed, color purity is increased, and monochromaticity is improved.

[0020] Microscopy is a method of measuring particle size and number directly on images taken with an optical microscope or electron microscope. Diameters used as indicators for evaluating particle size include Feret diameter, Heywood diameter, Martin diameter, and Krumbein diameter. From the perspective of ease of calculation by image analysis, the diameter evaluated using the Heywood diameter as an indicator is used as the particle size. When measuring particle size using microscopy, the particle size may vary depending on the measurement location. Taking this into consideration, when measuring particle size using microscopy, images are taken at multiple locations, and particle size is measured for each of the multiple images obtained. Furthermore, when measuring particle size using microscopy, images are taken at multiple locations, and the percentage of the total area occupied by particles with a particle size of 10 μm or more is calculated for each of the multiple images. Furthermore, when measuring particle size distribution using microscopy, the photographed range should include at least 100 particles. The method for calculating "the ratio of the total area occupied by particles having a particle diameter of 10 μm or more as measured by a microscopic method to the total area occupied by particles present within the captured image range" will be described in detail in the Examples.

[0021] In one embodiment, the crystallite size τ2 calculated by the Williamson-Hall equation represented by the following formula (b) based on an X-ray diffraction spectrum obtained by X-ray diffraction measurement is 34.5 nm or less: β cos θ = ε (2 sin θ) + Kλ / τ2 (b) θ: diffraction angle of diffraction peak [rad] β: half-width of diffraction peak [rad] K: shape factor λ: X-ray wavelength ε: lattice strain τ2: crystallite size X-ray diffraction measurement is performed by the method described in the examples.

[0022] In the above formula (b), the half-value width β of the diffraction peak is the half-value width (β ｓｉｚｅ ) and the half-width due to lattice distortion (β ｓｔｒａｉｎ The calculation of the crystallite size τ2 using the above formula (b) is carried out according to the procedure described in the Examples.

[0023] The effect of the crystallite size τ2 being 34.5 nm or less is similar to the effect of the crystallite size τ1 being less than 40 nm.

[0024] The crystallite size τ2 of the chalcogenide perovskite may be 32 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, 18 nm or less, 15 nm or less, 14.5 nm or less, or 10 nm or less. The lower limit of the crystallite size τ2 of the chalcogenide perovskite is not particularly limited, but may be, for example, 1 nm or more from the viewpoint of convenience in the manufacturing process.

[0025] A chalcogenide perovskite according to one embodiment is a compound having a perovskite-type crystal structure and containing chalcogen (a Group 16 element other than oxygen (S, Se, or Te)), and in addition to the chalcogen, contains two or more metal elements, such as a transition metal element and an alkaline earth metal element, as components of the perovskite-type crystal structure.

[0026] In one embodiment, the chalcogenide perovskite has a composition represented by, for example, the following formula (101) or (102): ABCh ３ ...(101) A' ２ A ｎ－１ B ｎ Ch ３ｎ＋１ ... (102)

[0027] In formulas (101) and (102), A and A' are Sr, Ba, or a combination thereof in any ratio, B is Zr, Hf, or a combination thereof in any ratio, and Ch is S, Se, Te, or a combination thereof in any ratio. In formula (102), n is an integer of 1 or more and 10 or less. In formula (102), A and A' may be the same or different.

[0028] In one embodiment, the chalcogenide perovskite may be a solid solution in which part or all of A, A', B, and Ch in the composition represented by formula (101) or (102) are substituted with other elements.

[0029] Chalcogenide perovskite (ABCh) represented by formula (101) ３) represents, for example, a cubic perovskite, a tetragonal perovskite, an orthorhombic perovskite, or a double perovskite crystal structure. ２ A ｎ－１ B ｎ Ch ３ｎ＋１ ) indicates, for example, the crystal structure of a Ruddlesden-Popper type layered perovskite.

[0030] In one embodiment, the chalcogenide perovskite particles are surface-modified with ligands, and the surface-modified chalcogenide perovskite particles of this embodiment can be easily dispersed in liquid dispersion media and solid dispersion media such as polymer compounds.

[0031] The type of ligand used to modify the surface of the chalcogenide perovskite is not limited, and any ligand generally used for dispersing nanoparticles may be used, such as one or more ligands selected from the group consisting of oleylamine, oleic acid, dodecanethiol, and trioctylphosphine.

[0032] The dispersion medium for dispersing the chalcogenide perovskite of this embodiment surface-modified with a ligand may be liquid or solid. The liquid dispersion medium (hereinafter referred to as liquid dispersion medium) may be, for example, a solvent selected from the group consisting of non-aqueous solvents such as toluene and hexane, and water, or a dispersion in which components other than the chalcogenide perovskite are dispersed in these solvents. The solid dispersion medium (hereinafter referred to as solid dispersion medium) may be, for example, a polymer compound such as polyethylene.

[0033] For example, in order to disperse chalcogenide perovskite particles synthesized by solid-phase synthesis in the above-mentioned dispersion medium, it is preferable to perform surface modification by modifying the particle surface with a ligand to improve dispersibility in various dispersion media. In contrast, when synthesizing chalcogenide perovskite particles by liquid-phase synthesis, the synthesis reaction is carried out in a state in which the ligand is previously present in the liquid phase that serves as the reaction liquid for the liquid-phase synthesis, thereby obtaining chalcogenide perovskite as particles surface-modified with the ligand.

[0034] (Composition) In a composition according to one embodiment, the chalcogenide perovskite according to this aspect described above is dispersed in a dispersion medium.

[0035] A composition according to one embodiment comprises the chalcogenide perovskite according to the present aspect, which has been surface-modified with a ligand, dispersed in a dispersion medium. As described above, chalcogenide perovskite surface-modified with a ligand can be easily dispersed in a liquid dispersion medium and a solid dispersion medium such as a polymer compound. Therefore, the composition according to this embodiment has the chalcogenide perovskite uniformly dispersed in the dispersion medium, and exhibits favorable properties as a composition.

[0036] A composition according to one embodiment is a dispersion using a liquid dispersion medium as the dispersion medium. In this specification, a chalcogenide perovskite dispersion refers to a dispersion in which chalcogenide perovskite is dispersed in a liquid dispersion medium. The phrase "chalcogenide perovskite dispersed" refers to a state in which the chalcogenide perovskite is suspended or floated in the liquid dispersion medium, and some of the chalcogenide perovskite may be precipitated in the dispersion.

[0037] The dispersion of chalcogenide perovskite may contain, in addition to chalcogenide perovskite, additives such as acids, bases, binder materials, etc., for the purpose of improving various properties of the chalcogenide perovskite, such as dispersibility, luminescence properties, and film-forming properties.

[0038] The sizes of the primary particles and secondary particles of the chalcogenide perovskite dispersed in the dispersion are not particularly limited, and the size of the primary particles in the dispersion is, for example, preferably 5 to 1000 nm, more preferably 5 to 100 nm, and even more preferably 5 to 20 nm.

[0039] The type of liquid dispersion medium used in the dispersion of chalcogenide perovskite is not particularly limited, and examples thereof include water, esters such as methyl formate, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, and pentyl acetate; ketones such as γ-butyrolactone, acetone, dimethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone; diethyl ether, methyl tert-butyl ether, diisopropyl ether, and the like. Ethers such as diethyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, 4-methyldioxolane, tetrahydrofuran, methyltetrahydrofuran, anisole, and phenetole; methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, 2-methyl-2-butanol, methoxypropanol, diacetone alcohol, cyclohexanol, 2-fluoropropyl alcohol, and the like; Examples of the liquid dispersion medium include alcohols such as ethanol, 2,2,2-trifluoroethanol, and 2,2,3,3-tetrafluoro-1-propanol; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, and triethylene glycol dimethyl ether; organic solvents having an amide group such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, acetamide, and N,N-dimethylacetamide; organic solvents having a nitrile group such as acetonitrile, isobutyronitrile, propionitrile, and methoxyacetonitrile; organic solvents having a carbonate group such as ethylene carbonate and propylene carbonate; organic solvents having a halogenated hydrocarbon group such as methylene chloride and chloroform; organic solvents having a hydrocarbon group such as n-pentane, cyclohexane, n-hexane, benzene, toluene, and xylene; and dimethyl sulfoxide. The liquid dispersion medium used in the dispersion of the chalcogenide perovskite may be used alone or in combination of two or more.

[0040] The use of the chalcogenide perovskite dispersion is not particularly limited. For example, it may be used as a film-forming material when forming a film by a solution film-forming method such as coating, spraying, or doctor blade, or as a composite composition combining the chalcogenide perovskite dispersion with a solid dispersion medium. Films and compositions prepared using the chalcogenide perovskite dispersion are used, for example, in the manufacture of various devices described below.

[0041] The method for producing a chalcogenide perovskite according to one embodiment of the present invention is described below. The method for producing a chalcogenide perovskite according to one embodiment of the present invention is characterized by reacting, in a liquid phase, a complex containing a first metal atom and a complex containing a second metal atom, both of which have ligands that do not contain oxygen atoms (O) or halogen atoms (X) as coordinating atoms. The inventors have discovered that when synthesizing a chalcogenide perovskite in a liquid phase, the presence of components containing halogen atoms (X), such as halides, or components containing oxygen atoms (O), such as acetates, during liquid-phase synthesis can inhibit the reaction and affect the purity and crystal structure of the target chalcogenide perovskite. Examples of halogen atoms (X) include fluorine atoms (F), chlorine atoms (Cl), bromine atoms (Br), and iodine atoms (I).

[0042] In this embodiment, a complex having a first metal atom and a complex having a second metal atom, both of which have ligands that do not contain oxygen atoms or halogen atoms as coordinating atoms, are reacted in the liquid phase. This allows the liquid-phase synthesis reaction to proceed without the presence of oxygen-containing components, such as metal acetates, or halogen-containing components, such as metal halides, in the liquid phase. This suppresses reactions between the constituent elements of the chalcogenide perovskite and oxygen atoms and halogen atoms in the liquid phase. As a result, a crystal structure similar to that obtained by solid-phase synthesis can be achieved. Below, the starting materials, the complex having a first metal atom and the complex having a second metal atom, and methods for producing the chalcogenide perovskite are described.

[0043] [Complex Having a First Metal Atom and Complex Having a Second Metal Atom] The ligands of the complex having a first metal atom and the complex having a second metal atom used in this embodiment are not particularly limited, as long as they do not contain an oxygen atom or a halogen atom as a coordinating atom. Examples include ligands coordinated with an atom selected from the group consisting of a nitrogen atom (N), a sulfur atom (S), a selenium atom (Se), a tellurium atom (Te), a carbon atom (C), and a phosphorus atom (P).

[0044] The ligands that coordinate with nitrogen atoms include alkylamines (NR amines) such as amine, dimethylamine, diethylamine, and methylethylamine. ２ arylamines (NHAr) such as phenylamine; trialkylsilylamines (N(SiR) such as silylamine and trimethylsilylamine) ３ ) ２ ), nitrogen-containing aromatic rings such as pyrazole, etc.

[0045] The ligands that coordinate with sulfur atoms include dithiocarbamate (S ２ CNR ２ ), xanthate (S ２ COR), trithiocarbamate (S ２ CSR), dithioester (S ２ Examples of the ligand that coordinates with a selenium atom or a tellurium atom include compounds in which some or all of the sulfur atoms of the above-mentioned ligand that coordinates with a sulfur atom are substituted with selenium atoms or tellurium atoms.

[0046] The complex having a first metal atom and the complex having a second metal atom may be a single compound (multinuclear complex). A single compound (multinuclear complex) refers to a compound having both a first metal atom and a second metal atom as the central metal ion of the complex. Preferably, the first metal atom and the second metal atom may be bonded via a ligand coordinated by a sulfur atom, a selenium atom, or a tellurium atom. Examples of multinuclear complexes in which the ligand is coordinated by a sulfur atom include heterobimetallic thiolates and heterobimetallic sulfides. In these multinuclear complexes, the first metal atom and the second metal atom are bonded via a thiolate or sulfide (a ligand coordinated by a sulfur atom) ligand. Examples of multinuclear complexes in which the ligand is coordinated by a selenium atom or a tellurium atom include those in which some or all of the sulfur atoms in a multinuclear complex in which the ligand is coordinated by a sulfur atom are replaced with selenium atoms or tellurium atoms.

[0047] Examples of the ligand coordinated at a carbon atom include alkanes such as methyl and ethyl; unsaturated hydrocarbon rings such as cyclopentadiene, cyclooctadiene, and indene, or benzyl groups and other groups derived from the above-mentioned unsaturated hydrocarbon rings; and cyanide (CN).

[0048] Examples of the ligands that coordinate with phosphorus atoms include trialkylphosphines (PRs) such as trioctylphosphine and tricyclohexylphosphine. ３ triarylphosphines (PAr) such as triphenylphosphine and tri(o-tolyl)phosphine; ３ ); diphosphine (R ２ P-(CH ２ ) ｍ -PR ２ ) etc.

[0049] The ligand may be a derivative of the above-mentioned ligand.

[0050] In each of the general formulas above, R is a hydrogen atom, a saturated hydrocarbon group having 1 to 20 carbon atoms, or an unsaturated hydrocarbon. When one ligand contains two or more R, the R may be the same or different from each other. Ar is an aryl group having 6 to 20 carbon atoms, such as a phenyl group, a naphthyl group, or an anthracenyl group, which may have a substituent. Examples of the substituent include an alkyl group having 1 to 10 carbon atoms. When one ligand contains two or more Ar, the Ar may be the same or different from each other. m is an integer from 1 to 10.

[0051] Among the above-mentioned ligands, ligands coordinated by nitrogen atoms or ligands coordinated by sulfur atoms are preferred. Also preferred are ligands having a structure selected from the group consisting of the following formulas (1) to (7): S ２ CNR ａ ２ (1) S ２ COR (2) S ２ CSR ａ (3) S ２ CR ａ (4) SR ａ (5) NR ａ ２ (6) N(SiR ａ ３ ) ２ (7) (wherein, R ａ is a hydrogen atom, a saturated hydrocarbon group having 1 to 20 carbon atoms, or an unsaturated hydrocarbon group having 1 to 20 carbon atoms. ａ When the ａ may be the same or different.)

[0052] Examples of the saturated hydrocarbon group and unsaturated hydrocarbon include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a cycloalkenyl group having 3 to 20 carbon atoms, a cycloalkynyl group having 3 to 20 carbon atoms, a cycloalkadienyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group and the unsaturated hydrocarbon may have a substituent. An example of the substituent is an alkyl group having 1 to 10 carbon atoms.

[0053] In one embodiment, the ligand is preferably a compound represented by the above formula (1). ａ is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 2 to 6 carbon atoms.

[0054] The ligand used in this embodiment can be synthesized by a conventional method, or a commercially available compound may be used.

[0055] The metal atom of the complex having the first metal atom is a metal atom selected from alkaline earth metal elements, and the metal atom of the complex having the second metal atom is a metal atom selected from transition metal elements. In one embodiment, the metal atom of the complex having the first metal atom is at least one of Sr and Ba, and the metal atom of the complex having the second metal atom is at least one of Zr and Hf. At least one of the metal atom of the complex having the first metal atom and the metal atom of the complex having the second metal atom may further include at least one selected from Ti, Ca, and Mg.

[0056] The complex having the first metal atom and the complex having the second metal atom can be synthesized by selecting raw material components according to the type of metal atom and ligand possessed by each of them and by a known method. Alternatively, a commercially available metal complex may be used. Hereinafter, as an example of a method for synthesizing a complex having the first metal atom and a complex having the second metal atom, a method for synthesizing a complex having a ligand (S ２ CNR ２ Metal complexes (M(S ２ CNR ２ )Ｘ ) synthesis will be described.

[0057] First, at least one selected from Ba, Sr, Ca, Mg, Zr, and Hf, or a salt thereof, is dissolved in a solvent such as water as a metal source (M) that serves as a source of metal atoms for the metal complex. The solvent is not particularly limited as long as it can dissolve the metal source (M), and may be, for example, an organic solvent. Next, ammonia or an amine compound is added to the solution containing the dissolved metal source as a source of nitrogen (N) contained in the complex ligand to be synthesized, and the mixture is stirred. As the amine compound, primary amines or secondary amines can be used without any particular limitation, and the type of substituted hydrocarbon group, etc., in these amine compounds is also not particularly limited.

[0058] Next, a source of sulfur (S) contained in the complex ligand to be synthesized is added to the solution containing the nitrogen (N) source and stirred. ２ However, other compounds can be used depending on the composition of the complex ligand to be synthesized. When Se or Te is contained instead of sulfur (S), CSe ２ , CTe ２ Next, the solid produced by stirring or the precipitate deposited in the solution can be isolated by a known method to obtain the target metal complex.

[0059] [Method for Producing Chalcogenide Perovskite] In this embodiment, the chalcogenide perovskite is produced by reacting the above-described complex having the first metal atom and complex having the second metal atom in a solvent. The solvent is selected based on the solubility of the complex having the first metal atom and complex having the second metal atom, and the H ２The solvent can be appropriately selected from the viewpoint of S generation efficiency, etc. Examples of the solvent include saturated aliphatic hydrocarbons, unsaturated aliphatic hydrocarbons, aromatic hydrocarbons, nitrogen-containing heterocyclic compounds, alcohols, aldehydes, carboxylic acids, primary amines, secondary amines, tertiary amines, phosphine compounds, and thiols. Taking into consideration that the liquid phase may be heated to a high temperature of, for example, 300°C or higher in the liquid-phase synthesis stage described below, it is preferable to use a solvent with a higher boiling point. For example, alkenes having 10 to 30 carbon atoms, such as octadecene, have a high boiling point and can be suitably used as the solvent.

[0060] In one embodiment, in addition to the complex having a first metal atom and the complex having a second metal atom, a chalcogen compound can be added to the liquid phase. For example, when neither the ligands of the complex having a first metal atom nor the complex having a second metal atom contain a chalcogen element such as sulfur (S), or when the chalcogen elements contained in the ligands are insufficient, the composition of the target chalcogenide perovskite can be adjusted by adding a chalcogen compound to the liquid phase. As the chalcogen compound, one that does not contain oxygen atoms (O) and halogen atoms (X) is preferably used. For example, sulfur or carbon disulfide (CS ２ ), hydrogen sulfide (H ２ S), selenium or selenides, tellurium or tellurides, hexanethiol, octanethiol, decanethiol, dodecanethiol (n-dodecanethiol, t-dodecanethiol), hexadecanethiol, mercaptopropylsilane, dialkylthiourea (S═C(NR ２ ) ２ ), sulfur-trioctylphosphine (trioctylphosphine sulfide; S-TOP), sulfur-tributylphosphine (S-TBP), sulfur-triphenylphosphine (S-TPP), sulfur-trioctylamine (S-TOA), bis(trimethylsilyl) sulfide, ammonium sulfide, sodium sulfide, selenium-trioctylphosphine (Se-TOP), selenium-tributylphosphine (Se-TBP), and selenium-triphenylphosphine. Among these, dialkylthioureas (S═C(NR２ ) and other thioureas, such as carbon disulfide (CS ２ ) and therefore can be suitably used as a chalcogen compound.

[0061] In one embodiment, in addition to the above-described complex having a first metal atom and complex having a second metal atom, an amine compound can be further added to the liquid phase. The amine compound functions as a reaction initiator. The amine compound may also be used as the above-described solvent. The amine compound is preferably one that does not contain an oxygen atom (O) or a halogen atom (X). Examples of the amine compound include alkylamines having one alkyl group, such as oleylamine, hexadecylamine, and octadecylamine; dialkylamines having two alkyl groups having 1 to 30 carbon atoms; and trialkylamines (e.g., trioctylamine) having three alkyl groups having 1 to 30 carbon atoms. From the viewpoint of fully exhibiting its function as a reaction initiator between the ligand and the metal component, the amine compound is preferably added in an amount equal to or greater than the total amount of the ligands contained in the complex having a first metal atom and the complex having a second metal atom added to the liquid phase. Furthermore, from the viewpoint of exhibiting the function as a surfactant that adheres to the particle surfaces of the chalcogenide perovskite finally obtained, the amine compound may be added to the liquid phase in an amount in excess of the aforementioned amount (equivalent to the total number of ligands).

[0062] The manufacturing method of this embodiment simply involves reacting the above-described complex having a first metal atom and complex having a second metal atom with, as needed, a chalcogen compound and an amine compound in a liquid phase, and the procedure is not particularly limited. The manufacturing method of this embodiment can be performed by known methods such as a hot injection method, a heat-up method, or a flow synthesis method. The compounding ratio of the complex having a first metal atom and the complex having a second metal atom can be adjusted according to the composition of the target chalcogenide perovskite.

[0063] In one embodiment of the manufacturing method, when raw material components include a complex having at least a first metal atom, a complex having a second metal atom, and a solvent, a first raw material containing at least the solvent and a second raw material containing at least the remaining raw material components not included in the first raw material are prepared. The second raw material is then added to the first raw material, causing a reaction. In this embodiment, it is preferable to preheat at least one of the first raw material and the second raw material, and then add the second raw material to the first raw material. Alternatively, the second raw material may be added to the first raw material and then heated to cause a reaction.

[0064] The manufacturing method of this embodiment will be described below using the hot injection method as an example. First, the first raw material is preheated. The temperature rise rate is not particularly limited, but is, for example, 1 to 30°C / min, typically 1 to 10°C / min. The temperature of the first raw material after heating is not particularly limited, but may be, for example, room temperature to 450°C, or 120 to 360°C.

[0065] Next, the second raw material is added to the first raw material to cause a reaction between the complex having the first metal atom and the complex having the second metal atom. The second raw material may also be preheated, as with the first raw material. The rate of addition of the second raw material is not particularly limited, but is preferably adjusted taking into account the decrease in liquid phase temperature due to the addition of the second raw material. The liquid phase temperature after mixing is preferably room temperature to 450°C, more preferably 120 to 360°C, and even more preferably 220 to 330°C.

[0066] For example, either the complex having the first metal atom or the complex having the second metal atom may contain a ligand represented by the above formula (1) (dithiocarbamate (S ２ CNR ２)), if the liquid phase temperature is 120°C or higher, the metal complex having the ligand can initiate a reaction with an amine compound, and the reaction between the complex having the first metal atom and the complex having the second metal atom proceeds smoothly. Note that the reaction can also be initiated without using an amine compound, but in this case, it is preferable to set the liquid phase temperature higher than 120°C. Furthermore, by setting the liquid phase temperature to 360°C or lower, evaporation of a commonly used solvent is suppressed, allowing for stable liquid phase synthesis.

[0067] In this embodiment, by adding the second raw material to the first raw material in a preheated state, once all of the components contributing to the synthesis of the chalcogenide perovskite (the solvent, the complex having the first metal atom, and the complex having the second metal atom) are in a liquid phase, all of these components are suddenly brought to a high temperature state, so that the reaction of the complex having the first metal atom and the reaction of the complex having the second metal atom can start at approximately the same time. As a result, the reaction of the complex having the first metal atom and the reaction of the complex having the second metal atom proceed in a well-balanced manner, allowing the synthesis of a high-purity chalcogenide perovskite.

[0068] In one embodiment, when the amine compound described above is added to the liquid phase as a reaction initiator, the raw material components include a solvent, a complex having a first metal atom, a complex having a second metal atom, and an amine compound. The combination of the first raw material component and the second raw material component is not particularly limited. For example, the first raw material may be a solvent alone, and the second raw material may be a mixture of a complex having a first metal atom, a complex having a second metal atom, and an amine compound. Alternatively, the first raw material may be a mixture of a solvent and an amine compound, and the second raw material may be a mixture of a complex having a first metal atom and a complex having a second metal atom. Alternatively, the first raw material may be a mixture of either a complex having a first metal atom or a complex having a second metal atom and a solvent, and the second raw material may be a mixture of the other of a complex having a first metal atom or a complex having a second metal atom and an amine compound.

[0069] In one embodiment, when the chalcogen compound is added to the liquid phase, the raw material components include a solvent, a complex having a first metal atom, a complex having a second metal atom, and a chalcogen compound. In this case, the combination of the first raw material component and the second raw material component is not particularly limited. For example, the first raw material may be a solvent alone, and the second raw material may be a mixture of a complex having a first metal atom, a complex having a second metal atom, and a chalcogen compound. Alternatively, the first raw material may be a mixture of a solvent and a chalcogen compound, and the second raw material may be a mixture of a complex having a first metal atom and a complex having a second metal atom. Alternatively, the first raw material may be a mixture of either a complex having a first metal atom or a complex having a second metal atom and a solvent, and the second raw material may be a mixture of the other of a complex having a first metal atom or a complex having a second metal atom and a chalcogen compound.

[0070] In one embodiment, the liquid phase obtained by adding the second raw material to the first raw material is heated and stirred for, for example, 0 to 24 hours while being maintained at a temperature of preferably room temperature to 450°C, more preferably 120 to 360°C, and even more preferably 220 to 330°C. After stirring is completed, the precipitate deposited in the liquid phase is isolated by a known method to obtain the target chalcogenide perovskite. The reasons why a temperature of 120°C or higher and a temperature of 360°C or lower are suitable are the same as those explained in the example using the hot injection method.

[0071] The above-mentioned series of liquid phase syntheses are preferably carried out in a state where components such as water and oxygen are removed as much as possible so that they are not present in the synthesis atmosphere. For example, the above-mentioned series of liquid phase syntheses are preferably carried out in an inert atmosphere filled with nitrogen or argon.

[0072] The manufacturing method of this embodiment may be performed, for example, by a flow synthesis method described below. First, a complex having a first metal atom, a complex having a second metal atom, and at least one of a chalcogen compound and an amine compound are dissolved in a solvent and circulated separately as three or four raw material flows. Next, the raw material flows are merged simultaneously or stepwise to initiate the reaction. At this time, it is preferable to preheat at least one of the raw material flows before merging. The raw material flow to be preheated is preferably the flow with the highest flow rate. Furthermore, since the reaction field in flow synthesis is small, the temperature can be instantly raised even if the raw material flows are heated immediately after merging, and the reaction of the complex having the first metal atom and the reaction of the complex having the second metal atom can start approximately simultaneously. The heating rate during heating and the temperature of the components after heating are the same as in the hot injection method. The following steps are the same as in the hot injection method.

[0073] According to flow synthesis, the components contributing to the synthesis of chalcogenide perovskite can be heated in a short time after joining, allowing the reaction of the complex containing the first metal atom and the complex containing the second metal atom to start at approximately the same time. Furthermore, because the reaction field is small in flow synthesis, the collision probability between the raw materials, i.e., reaction efficiency, is high. Therefore, the reaction of the complex containing the first metal atom and the reaction of the complex containing the second metal atom proceed in a well-balanced manner, allowing the synthesis of chalcogenide perovskite with high purity. Furthermore, the yield of chalcogenide perovskite is increased, reducing energy costs. Furthermore, the amount of waste impurities contained in the final synthesis product can be reduced, thereby reducing environmental impact. Furthermore, accidents such as explosions on the production line caused by impurities can be prevented, thereby improving production safety.

[0074] The manufacturing method of this embodiment described above can obtain chalcogenide perovskite particles without performing a calcination step. Generally, when a calcination step is performed, nano-sized primary particles aggregate to generate secondary particles. However, by not performing a calcination step, the generation of such secondary particles is suppressed. Therefore, chalcogenide perovskite nanoparticles with a fine crystallite size can be obtained.

[0075] The manufacturing method of this embodiment described above is based on a liquid-phase synthesis method, and therefore, compared to solid-phase synthesis, impurities are less likely to be mixed into the particles during the synthesis process. Furthermore, liquid-phase synthesis is characterized by uniform nucleation and particle growth from the liquid phase, and by preventing aggregation of the nuclei generated in the liquid phase, it is possible to obtain fine nanoparticles with a narrow particle size distribution (see, for example, "Kanie, S. et al., 'Liquid-Phase Synthesis of Size- and Shape-Controlled Functional Inorganic Nanoparticles and Their Application to Hybrid Materials by Surface Precise Organic Modification,' Journal of the Japanese Society for Crystal Growth, 2017, Vol. 44, No. 2, pp. 66-73"). Therefore, according to the manufacturing method of this embodiment, chalcogenide perovskite nanoparticles can be obtained that have little impurity mixed into the particles, a narrow and uniform particle size distribution, and fine crystallite sizes.

[0076] [Form in Use] The chalcogenide perovskite according to one embodiment of the present invention may be used in the form of, for example, a powder, a thin film, or a sheet.

[0077] (Powder) In this specification, the term "chalcogenide perovskite powder" refers to an aggregate or agglomeration of chalcogenide perovskite. The chalcogenide perovskite powder may contain additives other than chalcogenide perovskite for the purpose of improving various properties such as luminescence properties, dispersibility in other materials, and film-forming properties when used as a dispersion or other composition as described below.

[0078] In the following description, chalcogenide perovskite polycrystals (e.g., the polycrystal designated by reference numeral 20 in FIG. 1 ) or chalcogenide perovskite single crystals may be referred to as chalcogenide perovskite primary particles. Furthermore, in the following description, aggregates of chalcogenide perovskite primary particles may be referred to as secondary particles. In other words, chalcogenide perovskite powder refers to an aggregate of chalcogenide perovskite primary particles and / or secondary particles, or a mixture of these with additives. In this specification, when the chalcogenide perovskite primary particles are single crystals, the primary particle size d20 corresponds to the crystallite diameter d10. When the chalcogenide perovskite primary particles are polycrystals consisting of crystallites with a diameter d10 (corresponding to polycrystal 20 in FIG. 1 ), the primary particle size d20 corresponds to the diameter of polycrystal 20. The sizes of the primary and secondary particles of chalcogenide perovskite contained in the powder are not particularly limited. The size of the primary particles is, for example, preferably 5 to 1000 nm, more preferably 5 to 100 nm, and even more preferably 5 to 20 nm.

[0079] The primary particles or secondary particles of the chalcogenide perovskite may be surface-modified with a ligand. The type of ligand modifying the surface of the primary particles or secondary particles is not particularly limited, but examples thereof include one or more ligands selected from the group consisting of oleylamine, oleic acid, dodecanethiol, and trioctylphosphine.

[0080] The use of the chalcogenide perovskite powder is not particularly limited. For example, the chalcogenide perovskite powder may be dispersed in a liquid dispersion medium and used in the state of the aforementioned dispersion, or the chalcogenide perovskite powder may be dispersed in a resin or a solid medium (solid dispersion medium) and used as a composition. The chalcogenide perovskite powder may be sintered and used as a sintered body. The sintered body of the chalcogenide perovskite powder can be used, for example, as a sputtering target. The chalcogenide perovskite powder may be used in its powder state. The chalcogenide perovskite powder can be used, for example, as a deposition source when performing a deposition process.

[0081] (Thin Film) In this specification, a chalcogenide perovskite thin film refers to a film in which chalcogenide perovskite aggregates in a planar form. The chalcogenide perovskite thin film may contain materials other than chalcogenide perovskite as additives for the purpose of improving various properties such as the dispersibility of the chalcogenide perovskite in the film and the light emission properties.

[0082] The sizes of the primary particles and secondary particles of the chalcogenide perovskite contained in the thin film of chalcogenide perovskite are not particularly limited. The size of the primary particles contained in the thin film is, for example, preferably 5 to 1000 nm, more preferably 5 to 100 nm, and even more preferably 5 to 20 nm.

[0083] The method for producing the above-described thin film is not particularly limited. For example, a chalcogenide perovskite thin film may be formed by forming a film using a solution film-forming method such as coating, spraying, doctor blade, or inkjet printing using a dispersion in which nanoparticles of chalcogenide perovskite are dispersed in a liquid dispersion medium, or a precursor material of chalcogenide perovskite (e.g., a dispersion in which a complex having a first metal atom and a complex having a second metal atom are dispersed in a dispersion medium), followed by drying, baking, or other treatments as necessary. For example, when a precursor material (a dispersion in which a complex having a first metal atom and a complex having a second metal atom are dispersed in a dispersion medium) is used as the film-forming material and a solution film-forming method such as coating is formed, the coating film is heated at a predetermined temperature, whereby the complex having the first metal atom and the complex having the second metal atom react in the coating film. This results in a thin film containing a chalcogenide perovskite according to one embodiment of the present invention. The method for producing the thin film is not limited to the above-mentioned film formation methods, and for example, a chalcogenide perovskite thin film may be formed by forming chalcogenide perovskite nanoparticles (e.g., powder containing nanoparticles, a molded or fired body of the powder, etc.) or a chalcogenide perovskite precursor material into a film using a vacuum process such as sputtering or vacuum deposition, and then performing firing or other treatments as necessary. When performing treatments such as heating or firing, the chalcogenide perovskite in the thin film finally obtained does not necessarily have to maintain the particle shape it had before the heating treatment or other treatments.

[0084] (Sheet) In this specification, a chalcogenide perovskite sheet refers to a planar composition in which chalcogenide perovskite is dispersed in a solid dispersion medium. The chalcogenide perovskite sheet may contain, in addition to the chalcogenide perovskite, additives such as silica fine particles, acids, bases, binder materials, etc., for the purpose of improving various properties such as the dispersibility and luminescence characteristics of the chalcogenide perovskite.

[0085] The sizes of the primary particles and secondary particles of the chalcogenide perovskite contained in the chalcogenide perovskite sheet are not particularly limited, and the size of the primary particles contained in the sheet is preferably, for example, 5 to 1000 nm, more preferably 5 to 100 nm, and even more preferably 5 to 20 nm.

[0086] The solid dispersion medium used in the chalcogenide perovskite sheet may be any known polymeric material used for this purpose. In one embodiment, the polymeric material used as the solid dispersion medium in the chalcogenide perovskite sheet is preferably one that exhibits a translucent or nearly transparent appearance when formed into a sheet.

[0087] The solid dispersion medium used in the chalcogenide perovskite sheet is not particularly limited, but examples thereof include polyvinyl butyral, polyvinyl acetate, silicone, and silicone derivatives. Examples of silicone derivatives include polyphenylmethylsiloxane, polyphenylalkylsiloxane, polydiphenylsiloxane, polydialkylsiloxane, fluorinated silicones, and vinyl- and hydride-substituted silicones. In addition to the above, examples of the solid dispersion medium for the sheet include ionomer, polyethylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polypropylene, polyester, polycarbonate, polystyrene, polyacrylonitrile, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methacrylic acid copolymer film, nylon, etc.

[0088] The method for producing the above-mentioned sheet is not particularly limited. For example, a chalcogenide perovskite sheet may be produced by kneading the above-mentioned chalcogenide perovskite powder with a solid dispersion medium and stretching the mixture. Alternatively, the chalcogenide perovskite sheet may be produced by applying a dispersion liquid, which is a mixture of a liquid composition obtained by mixing a chalcogenide perovskite with various additives and a solid dispersion medium or a precursor of the solid dispersion medium, to a sheet and then drying the sheet as necessary.

[0089] In the thin films and sheets described above, the primary particles or secondary particles of the chalcogenide perovskite contained therein may be surface-modified with a ligand. The type of the ligand is not particularly limited, but for example, the same ligands as those exemplified in the section on chalcogenide perovskite powder can be used.

[0090] [Uses] The uses of the chalcogenide perovskite obtained by the production method of this embodiment are not particularly limited. The chalcogenide perovskite according to one embodiment of the present invention is suitable, for example, as a light-emitting material in light-emitting devices such as displays, wavelength conversion elements, and photoelectric conversion elements.

[0091] The chalcogenide perovskite according to one embodiment of the present invention, or the powder, dispersion, thin film, or sheet using the same, can be used, for example, for down-conversion of ultraviolet light or blue light in various devices. The chalcogenide perovskite according to one embodiment of the present invention, or the powder, dispersion, thin film, or sheet using the same, can be suitably used in the manufacture of various devices, such as light-emitting devices such as LEDs and organic EL devices, display devices including the light-emitting devices, lighting devices including the light-emitting devices, image sensors, photoelectric conversion devices, and bioluminescent labels. These various devices may have, for example, a thin film or sheet containing the chalcogenide perovskite according to one embodiment of the present invention.

[0092] Preparation Example 1 (Synthesis of Ba diisobutyldithiocarbamate) Barium hydroxide (5140 mg) was weighed into a 100 ml three-neck flask, 50 ml of purified water was added, and the flask was sealed and stirred. Next, diisobutylamine (10.39 ml) was added to the three-neck flask, and after stirring for an additional 10 minutes, carbon disulfide (3.63 ml) was added and stirred for 3 hours. Gradual precipitation of a white solid was observed upon stirring. The precipitated solid was collected by filtration, washed with hexane, and then vacuum dried to obtain a compound containing Ba diisobutyldithiocarbamate. The yield was approximately 70%.

[0093] Preparation Example 2 (Synthesis of Zr diisobutyldithiocarbamate) Zirconium chloride (2913 mg) was weighed into a 200 ml three-neck flask, 75 ml of THF was added, and the container was sealed and stirred for approximately 15 minutes. Next, diisobutylamine (29.2 ml) was added to the three-neck flask and stirred for 10 minutes. After that, carbon disulfide (10.2 ml) was added and stirred for an additional 3 hours. After stirring was completed, the precipitated solid was filtered, and the filtrate was recovered and transferred to another container. The solvent was then removed from the recovered filtrate using a known method, and the resulting residue was dispersed in hexane to obtain a white suspension. The white suspension was filtered, and the resulting solid was washed with hexane and then vacuum-dried to obtain a synthetic product containing Zr diisobutyldithiocarbamate. The yield was approximately 80%.

[0094] Example 1 Ba diisobutyldithiocarbamate (527.94 mg) obtained in Production Example 1 and Zr diisobutyldithiocarbamate (908.76 mg) obtained in Production Example 2 were weighed into a 50 ml three-necked flask, and 1-octadecene (5 ml) was added and stirred. Then, the three-necked flask was heated to a temperature of 1000° C., and the internal atmosphere was changed to N 2 ２ While still in the ambient atmosphere, the flask was moved into a draft and heated to 310°C at a rate of 5°C / min, after which room temperature oleylamine (1600 mg) was injected using a Luer-lock syringe. The solution in the three-neck flask was then stirred for 3 hours while maintained at 310°C, after which an excess amount of 1-butanol was added to the flask to rapidly cool (quench). The solution in the three-neck flask was then recovered and centrifuged, and the recovered solid was redispersed in hexane and filtered to obtain a synthesized product.

[0095] Example 2 A synthetic product was obtained in the same manner as in Example 1, except that the amount of oleylamine injected into the three-neck flask was changed from 1600 mg to 3200 mg.

[0096] Comparative Example 1: Synthesis was performed in the same manner as in Example 1 of US 2019 / 0225883 Al. First, a metal precursor mixture consisting of barium acetate and zirconium acetate hydroxide mixed in a 1:1 (molar ratio) ratio, and oleic acid were dissolved in 1-octadecene as a solvent in a 200 ml reaction vessel and heated at 90°C under vacuum for 60 minutes. The amount of oleic acid was 10 moles per mole of the metal precursor mixture. Next, the atmosphere in the reaction vessel was replaced with nitrogen gas, and the temperature inside the reactor was raised to 330°C. Next, a solution of sulfur dispersed in octadecene (S / ODE) was injected into the reaction vessel, and the mixture was reacted for 30 minutes while the temperature inside the reaction vessel was maintained at 310°C. The amount of sulfur injected was approximately 10 moles per mole of the metal precursor mixture. Next, the temperature of the reaction solution in the reaction vessel was rapidly cooled to room temperature, acetone was added, and the mixture was centrifuged. The resulting precipitate was dispersed in toluene, and the synthesized product was recovered from the resulting dispersion.

[0097] [X-ray diffraction analysis] X-ray diffraction analysis was performed on the synthesized products obtained in Example 1, Example 2, and Comparative Example 1 by the following method. X-ray wavelength: 1.5418 Å (CuKα radiation) Measurement range: 5 to 60 (deg) Measurement method: 2θ-θ method Measurement sample: A sample powder of the synthesized product obtained in Example 1, Example 2, and Comparative Example 1 was filled into a glass sample holder with a depression, and the surface was smoothed using a glass plate, and then measurement was performed. The X-ray diffraction spectra obtained for Example 1 and Example 2 are shown in Figure 2.

[0098] In each of the X-ray diffraction spectra obtained for Example 1, Example 2, and Comparative Example 1, the peak positions showing the five highest peak intensities are shown in Table 1 (Example 1 and Example 2) and Table 2 (Comparative Example 1), respectively. Table 1 also shows the peak positions of BaZrS synthesized by solid phase synthesis. ３ (GdFeO ３For the orthorhombic perovskite (space group Pnma), the peak positions showing the top five peak intensities from the highest peak intensity in the X-ray diffraction spectrum, as confirmed from JCPDS card No. 00-015-0327 and ICSD (Inorganic Crystal Structure Database) #23288, and their respective lattice plane indices are also shown. In Figure 2, the peak positions of the X-ray diffraction pattern confirmed from the above database (JCPDS card No. 00-015-0327 and ICSD (Inorganic Crystal Structure Database) #23288) are shown as straight lines.

[0099] As a result of the above-mentioned X-ray diffraction, the peak of the X-ray diffraction spectrum obtained for Comparative Example 1 was approximately the same as the X-ray diffraction spectrum (FIG. 4) shown for Example 1 of US 2019 / 0225883 Al.

[0100]

[0101]

[0102] From Table 1, the synthesized products obtained in Examples 1 and 2 are BaZrS synthesized by solid phase synthesis based on the JCPDS card, with the peak positions showing the top five peak intensities in the X-ray diffraction analysis spectrum being the same as those of BaZrS ３ (GdFeO ３ It was confirmed that the peak positions of the compound obtained in Comparative Example 1 were almost identical to those of the compound obtained in Comparative Example 2 (orthorhombic perovskite). Taking into account measurement errors caused by the measuring equipment, a deviation of the peak positions within ±1 (deg) from the peak positions based on the JCPDS card is within the acceptable range. On the other hand, the peak positions showing the top five peak intensities in the X-ray diffraction analysis spectrum of the compound obtained in Comparative Example 1 were almost identical to those of the compound obtained in Comparative Example 2 (orthorhombic perovskite). ３ That is, BaZrS ３ Components other than BaZrS are mixed in the compound, or BaZrS of the structure described in the JCPDS card is ３ These results suggest that it has not been possible to synthesize it as a main component.

[0103] [Particle size by Scherrer equation] In the X-ray diffraction spectra (see FIG. 2) obtained for Examples 1 and 2, the crystallite size τ1 was calculated by the Scherrer equation represented by the following formula (a) based on the diffraction peak 1 with the maximum peak height. The results are shown in Table 3. The half-value width β was determined by connecting both ends of the rising edge of the peak in the X-ray diffraction analysis spectrum shown in FIG. 2 with a straight line to remove the background, and then fitting with a split pseudo-Voigt function.

[0104] τ1=Kλ / βcosθ (a) θ: diffraction angle of maximum peak [rad] β: half width of maximum peak [rad] K: shape factor λ: X-ray wavelength τ1: crystallite size

[0105]

[0106] [Particle size by Williamson-Hall equation] Based on each diffraction peak of the X-ray diffraction spectrum (see FIG. 2) obtained for Examples 1 and 2, the crystallite size τ2 was calculated by the Williamson-Hall equation (b) shown below. The half-value width β was determined by connecting both ends of the rising edge of the peak in the X-ray diffraction analysis spectrum shown in FIG. 2 with a straight line to remove the background, and then fitting with a split pseudo-Voigt function.

[0107] β cos θ = ε (2 sin θ) + Kλ / τ2 (b) θ: diffraction angle of diffraction peak [rad] β: half-width of diffraction peak [rad] K: shape factor λ: X-ray wavelength ε: lattice strain τ2: crystallite size

[0108] Specifically, the crystallite size τ2 is determined by substituting the diffraction angle θ and half-width β (see Table 4) for each diffraction peak observed in the X-ray diffraction spectrum shown in FIG. 2 (Peak 1: 25 deg (0.22 rad), Peak 2: 45 deg (0.39 rad), Peak 3: 52 deg (0.45 rad)) into the above formula (b), and plotting each sin θ as the x-axis and β cos θ as the y-axis to create an approximate straight line. The approximate straight line (y = 0.0248x + 0.0101) created by plotting Peak 1, Peak 2, and Peak 3 of Example 1 is shown in FIG. 3A. The approximate straight line (y = 0.0188x + 0.0192) created by plotting Peak 1, Peak 2, and Peak 3 of Example 2 is shown in FIG. 3B.

[0109]

[0110] Next, the lattice strain ε was calculated from the slope (2ε) of each approximate line, and the crystallite size τ2 was calculated from the intercept (Kλ / τ2). The results are shown in Table 5.

[0111]

[0112] Two arbitrarily selected locations on the composite obtained in Example 1 were observed using a scanning electron microscope (manufactured by JEOL Ltd., "JSM-7610F") at an accelerating voltage of 5 kV and a magnification of 250,000 times (hereinafter referred to as SEM observation). Images obtained by SEM observation using a scanning electron microscope (hereinafter referred to as SEM images) on the composite obtained in Example 1 are shown in FIGS. 4 and 5. The SEM images shown in FIGS. 4 and 5 were both taken so that 260 or more particles were included within the image range. One image of the two observed locations is shown in FIG. 4, and the other image is shown in FIG. 5. Furthermore, two arbitrarily selected locations on the composite obtained in Example 2 were observed using a scanning transmission electron microscope (manufactured by JEOL Ltd., "JSM-7610F") at an accelerating voltage of 5 kV and a magnification of 200,000 times or 400,000 times (hereinafter referred to as STEM observation). Specifically, one of two arbitrarily selected locations on the composite obtained in Example 2 was observed at a magnification of 200,000 times, and the other location was observed at a magnification of 400,000 times. Images (hereinafter referred to as STEM images) obtained by STEM observation of the composite obtained in Example 2 using a scanning transmission electron microscope are shown in FIG. 6 (magnification: 200,000 times) and FIG. 7 (magnification: 400,000 times). The STEM image shown in FIG. 6 was taken so that 200 or more particles were included within the captured image range. The STEM image shown in FIG. 7 was taken so that 450 or more particles were included within the captured image range.

[0113] In each of the images shown in FIGS. 4 to 7, the Heywood diameter of the particles that can be confirmed in the image is measured, and among the particles to be measured, particles P having a Heywood diameter of 10 μm or more are Ｌ The particle P present within the image range was identified. Ｌ The total area occupied by particles P present in the image was calculated for each image, and the ratio of the total area occupied by particles present within the image range was calculated using the following formula (α): Ｌ(total area occupied by particles present in the image) / (total area occupied by particles present in the image)×100 (α) In the SEM image shown in Figure 4, the value calculated by formula (α) was 0%, and in the SEM image shown in Figure 5, the value calculated by formula (α) was 0%. Similarly, in the STEM image shown in Figure 6, the value calculated by formula (α) was 0%, and in the STEM image shown in Figure 7, the value calculated by formula (α) was 0%.

[0114] In each of the SEM images shown in Figures 4 and 5, the width indicated by the white line at the bottom corresponds to 100 nm. As can be seen from Figures 4 and 5, in none of the SEM images taken of the composite of Example 1 were particles having a particle diameter (Heywood diameter) exceeding 100 nm confirmed. Similarly, in the STEM image shown in Figure 6, the width indicated by the white line at the bottom corresponds to 100 nm, and in the STEM image shown in Figure 7, the width indicated by the white line at the bottom corresponds to 10 nm. As can be seen from Figures 6 and 7, in none of the STEM images taken of the composite of Example 2 were particles having a particle diameter (Heywood diameter) exceeding 100 nm confirmed.

[0115] The chalcogenide perovskite of the present invention can be applied to, for example, a light-emitting material in a light-emitting device such as a display, a wavelength conversion element, or a photoelectric conversion element.

[0116] Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will readily be able to make numerous modifications to these exemplary embodiments and / or examples without substantially departing from the novel teachings and advantages of the present invention. Accordingly, these numerous modifications are within the scope of the present invention. The contents of all documents cited in this specification and of the applications from which this application claims priority under the Paris Convention are incorporated by reference in their entirety.

Claims

1. In the X-ray diffraction spectrum obtained by X-ray diffraction measurement, based on the diffraction peak with the maximum peak height, the crystallite size τ1 calculated by the Scherrer equation is less than 40 nm, and in the image range photographed by a microscope, the ratio of the total area occupied by particles having a particle diameter of 10 μm or more measured by the microscopic method to the total area occupied by particles present in the photographed image range is 10% or less, a chalcogenide perovskite.

2. The chalcogenide perovskite according to claim 1, wherein the crystallite size τ2 calculated by the Williamson-Hall equation based on the X-ray diffraction spectrum obtained by X-ray diffraction measurement is 34.5 nm or less.

3. The chalcogenide perovskite according to claim 2, wherein the crystallite size τ2 is 30 nm or less.

4. The chalcogenide perovskite according to any one of claims 1 to 3, wherein the crystallite size τ1 is less than 17.5 nm.

5. The chalcogenide perovskite according to any one of claims 1 to 3, wherein the chalcogenide perovskite has a composition represented by the following formula (101) or (102). ABC h ３ ... (101) A' ２ A ｎ－１ B ｎ Ch ３ｎ＋１ ・・・(102) (In formula (101) and (102), A and A' are each Sr, Ba, or a combination thereof, B is Zr, Hf, or a combination thereof, and Ch is S, Se, Te, or a combination thereof. In formula (102), n is an integer of 1 or more and 10 or less. In formula (102), A and A' may be the same as or different from each other. The chalcogenide perovskite may be a solid solution in which part or all of A, A', B, and Ch in the composition represented by formula (101) or (102) are substituted with other elements.)

6. The chalcogenide perovskite according to any one of claims 1 to 3, wherein the particles of the chalcogenide perovskite are surface-modified with ligands.

7. A composition in which the chalcogenide perovskite according to any one of claims 1 to 3 is dispersed in a dispersion medium.

8. The composition according to claim 7, which is a dispersion using a liquid dispersion medium as the dispersion medium.

9. The composition according to claim 8, wherein the liquid dispersion medium is at least one selected from the group consisting of water, ester, ketone, ether, alcohol, glycol ether, an organic solvent having an amide group, an organic solvent having a nitrile group, an organic solvent having a carbonate group, an organic solvent having a halogenated hydrocarbon group, an organic solvent having a hydrocarbon group, and dimethyl sulfoxide.

10. The composition according to claim 7, which is a sheet using a solid dispersion medium as the dispersion medium.

11. The composition according to claim 10, wherein the solid dispersion medium is at least one selected from the group consisting of polyvinyl butyral, polyvinyl acetate, and silicone and its derivatives.

12. A powder containing a chalcogenide perovskite according to any one of claims 1 to 3.

13. The powder according to claim 12, wherein the primary particles or secondary particles of the chalcogenide perovskite are surface-modified with a ligand.

14. A sintered body obtained by sintering the powder according to claim 12.

15. A thin film containing a chalcogenide perovskite according to any one of claims 1 to 3.

16. A method for producing the thin film according to claim 15, wherein the dispersion liquid according to claim 8 is formed into a film by a coating method, a spraying method, a doctor blade method, or an inkjet method.

17. A method for producing the thin film according to claim 15, wherein the powder of the chalcogenide perovskite according to claim 12 is formed into a film by a sputtering method or a vacuum evaporation method.

18. A method for producing the sheet according to claim 10, wherein the dispersion liquid according to claim 8 is applied in a sheet shape and then dried.

19. A light-emitting material containing a chalcogenide perovskite according to any one of claims 1 to 3.

20. A light-emitting device, an image sensor, a photoelectric conversion device, or a bioluminescent label containing a chalcogenide perovskite according to any one of claims 1 to 3.

21. A method for producing a chalcogenide perovskite, comprising reacting a complex having a first metal atom and a complex having a second metal atom in a liquid phase, The production method, wherein the complex having the first metal atom and the complex having the second metal atom have a ligand that does not contain an oxygen atom (O) and a halogen atom (X) as coordination atoms.

22. The production method according to claim 21, wherein the complex having the first metal atom and the complex having the second metal atom each have a ligand coordinated by an atom selected from the group consisting of a nitrogen atom (N), a sulfur atom (S), a selenium atom (Se), a tellurium atom (Te), a carbon atom (C), and a phosphorus atom (P).

23. The metal atom of the complex having the first metal atom is at least one of Sr and Ba, The production method according to claim 21 or 22, wherein the metal atom of the complex having the second metal atom is at least one of Zr and Hf.

24. Furthermore, at least one selected from Ti, Ca, and Mg is used for at least one of the metal atom of the complex having the first metal atom and the metal atom of the complex having the second metal atom. The production method according to claim 23.

25. The ligand is dithiocarbamate, xanthate, trithiocarbamate, dithioester, thiolate, sulfide, or a compound in which some or all of the sulfur atoms contained therein are substituted with selenium atoms or tellurium atoms, alkylamine, arylamine, trialkylsilylamine, nitrogen-containing aromatic ring, alkane, unsaturated hydrocarbon ring, or a group derived from the unsaturated hydrocarbon ring, cyanide, trialkylphosphine, triarylphosphine, or diphosphine. The production method according to claim 21 or 22.

26. The production method according to claim 21 or 22, wherein the complex having the first metal atom and the complex having the second metal atom are a multinuclear complex that is a single compound.

27. The production method according to claim 26, wherein the first metal atom and the second metal atom are bonded via a ligand coordinated by a sulfur atom, a selenium atom, or a tellurium atom.

28. The production method according to claim 21 or 22, wherein the chalcogenide perovskite has a composition represented by the following formula (101) or (102). ABC h ３ ...(101) A' ２ A ｎ－１ B ｎ Ch ３ｎ＋１ ・・・(102) (In Formulas (101) and (102), A and A' are each Sr, Ba, or a combination thereof; B is Zr, Hf, or a combination thereof; and Ch is S, Se, Te, or a combination thereof. In Formula (102), n is an integer of 1 or more and 10 or less. In Formula (102), A and A' may be the same as or different from each other. The chalcogenide perovskite may be a solid solution in which part or all of A, A', B, and Ch are substituted with other elements in the composition represented by Formula (101) or (102).)

29. The production method according to claim 21 or 22, further comprising adding a chalcogen compound.

30. The production method according to claim 21 or 22, further comprising adding an amine compound.

31. The production method according to claim 21 or 22, wherein the temperature of the liquid phase is from room temperature to 450°C.

32. The production method according to claim 31, wherein the temperature of the liquid phase is from 120°C to 360°C.

33. The reaction is caused by adding a second raw material containing at least a raw material component not contained in the first raw material among the raw material components including the complex having the first metal atom, the complex having the second metal atom, and the solvent to the first raw material containing at least the solvent, according to the production method described in claim 21 or 22.

34. The production method according to claim 33, wherein the second raw material is added to the first raw material in a state where at least one of the first raw material and the second raw material is pre-heated to cause the reaction.

35. The production method according to claim 33, wherein after adding the second raw material to the first raw material, the first raw material and the second raw material are heated to cause the reaction.

36. A dispersion liquid in which the complex having the first metal atom and the complex having the second metal atom are dispersed in a dispersion medium is formed into a film by a coating method, a spraying method, a doctor blade method, or an inkjet method, and the obtained coating film is heat-treated, according to the production method described in claim 35.

37. The production method according to claim 21 or 22, wherein the complex having the first metal atom, the complex having the second metal atom, and at least one of a chalcogen compound and an amine compound are simultaneously mixed to cause the reaction.

38. The manufacturing method according to claim 37, wherein a complex having the first metal atom, a complex having the second metal atom, and at least one of the chalcogen compound and the amine compound are each circulated as an independent flow, and the reaction is caused by simultaneously merging the flows.

39. The manufacturing method according to claim 37, wherein at least one of a complex having the first metal atom, a complex having the second metal atom, and at least one of the chalcogen compound and the amine compound is preheated.