JP2017133077A - Production film of perovskite film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing simply, easily and industrially advantageously a perovskite film having a good-quality perovskite structure.SOLUTION: A precursor solution of a perovskite structure body containing gamma-butyrolactone is atomized or changed into droplets, and the acquired mist or droplets are conveyed to a substrate installed in a film deposition chamber by carrier gas, thereafter, the mist or the droplets are thermally reacted to thereby deposit the perovskite structure body on the substrate, and then annealed. The obtained perovskite film is applied to a photoelectric conversion element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a perovskite film useful for a photoelectric conversion element.

  Perovskite-type composite oxides having a perovskite structure are used and studied in a wide range of fields because they exhibit various physical properties. Such a perovskite type complex oxide has physical properties such as anion conduction such as oxide ion conduction, cation conduction such as lithium ion conduction, proton conduction, electron conduction, ferroelectricity, ferromagnetism or high temperature superconductivity. Indicates.

As a method for producing a perovskite complex oxide, as described in Patent Document 1, as a technique for forming a lead-based ferroelectric film, physical vapor deposition, chemical vapor deposition, sol-gel method, MOD method In addition, a mist CVD method is also given as an example. However, as described in Patent Document 1, the film formed on the substrate by these methods must be heat-treated. In particular, in order to obtain a tetragonal perovskite structure, 600 ° C. to 800 ° C. In this case, it is necessary to perform crystallization annealing. Further, examples of the tetragonal perovskite film was produced by the mist CVD is not, Patent Document 1 mist CVD method described, the recently, α-Ga ₂ O ₃ system mist CVD method has been studied as a semiconductor manufacturing method In contrast, this is a method in which a misted raw material solution is applied on a substrate and then heat-treated.

Patent Document 2 includes a spin coating method, a chemical vapor deposition (CVD) method, a sputtering method, and the like as a method for producing a perovskite complex oxide, and a mist-like ferroelectric material solution is used as a substrate. An example is a mist CVD method in which the mist is applied and heat-treated. However, as described in Patent Document 2, the perovskite-type composite oxide obtained by deposition by these methods does not exhibit properties that are sufficient for practical use as it is, and therefore needs to be annealed and crystallized. is there. When annealing is performed at a high temperature, there is a problem that the characteristics of the perovskite structure deteriorate due to a reaction occurring at the interface, diffusion or desorption of thin film constituent atoms, oxygen desorption of thin film constituent atoms, etc. is there. Therefore, in Patent Document 2, it is studied to irradiate a continuous wave laser beam instead of annealing. However, such a laser irradiation method also allows the heat of the laser irradiated to the oxide layer to easily escape through the base layer disposed under the oxide layer, so that the temperature of the oxide layer is selected selectively. However, there is a problem that the oxide is not sufficiently crystallized and the base layer is oxidized. Moreover, there is no example that the perovskite film was actually manufactured by mist CVD. Then, as described in Patent Document 2 as a mist CVD method, a method of applying a mist-formed raw material solution on a substrate and performing a heat treatment has recently been studied as a method for manufacturing an α-Ga ₂ O ₃ based semiconductor. This is different from the mist CVD method.

Japanese Patent Laid-Open No. 10-172348 International Publication No. 2008/004571

  An object of the present invention is to provide a method for industrially producing a perovskite film having a high-quality perovskite structure.

As a result of diligent studies to achieve the above object, the inventors of the present invention atomized or dropletized the precursor solution of the perovskite structure, transported the obtained mist or droplet to the substrate with a carrier gas, It was found that a perovskite film having a high-quality perovskite structure can be easily formed by annealing the mist or droplets on the substrate to form a film of the perovskite structure and then annealing at a low temperature. Such a method can be realized under atmospheric pressure, and the obtained perovskite film has good physical properties. I found out that it can be solved.
Moreover, after obtaining the said knowledge, the present inventors repeated investigation further, and came to complete this invention.

That is, the present invention relates to the following inventions.
[1] A perovskite structure precursor solution containing γ-butyrolactone as a solvent is atomized or dropletized, and the resulting mist or droplet is transported to a substrate with a carrier gas, and then the mist or droplet is thermally reacted. Then, after the perovskite structure is formed on the substrate, an annealing process is performed, and a method for producing a perovskite film is provided.
[2] The method according to [1], wherein the precursor solution contains an organometallic halide.
[3] The production method according to [1] or [2], wherein the precursor solution contains an ammonium compound.
[4] The production method according to any one of [1] to [3], wherein the solvent of the precursor solution is composed of an organic solvent.
[5] The production method of the above-mentioned [4], wherein the organic solvent is composed of an aprotic solvent.
[6] The production method according to [4] or [5], wherein the organic solvent is represented by the following formula (1).
(In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent. , R ¹ and R ² may combine to form a ring.)
[7] The production method according to [4] or [5], wherein the organic solvent contains a compound represented by the following formula (2).
(Wherein R ³ , R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom, a halogen atom or an optionally substituted hydrocarbon group or an optionally substituted heterocyclic ring. Represents a group, and any two groups selected from R ³ , R ⁴ and R ⁵ may combine to form a ring.)
[8] The production method according to any one of [1] to [7], wherein the thermal reaction is performed at a temperature of 250 ° C. or lower.
[9] The manufacturing method according to any one of [1] to [8], wherein the base is a glass substrate.
[10] The manufacturing method according to any one of [1] to [9], wherein the substrate includes a tin-doped indium oxide film.
[11] The production method according to any one of [1] to [10], wherein the substrate includes a titania film.
[12] A perovskite film manufactured using the manufacturing method according to any one of [1] to [11].
[13] A photoelectric conversion element comprising the perovskite film according to [12].

  According to the production method of the present invention, a high-quality perovskite film can be obtained industrially advantageously.

It is a schematic block diagram of the film-forming apparatus (mist CVD) used in the Example. (B) is a 1000 times SEM image, and (c) is a 5000 times SEM image.

  In the method for producing a perovskite film of the present invention, a precursor solution of a perovskite structure containing γ-butyrolactone as a solvent (hereinafter also referred to as “raw material solution”) is atomized or dropletized (atomization / droplet forming step). Then, the obtained mist or droplet is transported to a substrate with a carrier gas (mist transporting step), and then the perovskite structure is formed on the substrate by thermally reacting the mist or droplet (film forming step). It is characterized by annealing treatment (annealing process).

(Atomization / droplet forming process)
In the atomization / droplet forming step, the raw material solution is atomized or dropletized. The atomizing means or the droplet forming means is not particularly limited as long as the raw material solution can be atomized or formed into droplets, and may be a known means, but in the present invention, the atomizing means using ultrasonic waves or A droplet forming means is preferred. Mist or droplets obtained using ultrasonic waves have a zero initial velocity and are preferable because they float in the air.For example, instead of spraying like a spray, they can be suspended in a space and transported as a gas. Since it is a possible mist, there is no damage due to collision energy, which is very suitable. The droplet size is not particularly limited and may be a droplet of several millimeters, but is preferably 50 μm or less, and more preferably 100 nm to 10 μm.

(Raw material solution)
The raw material solution is a precursor solution of a perovskite structure containing γ-butyrolactone as a solvent, and is not particularly limited as long as atomization or droplet formation is possible, and may contain an inorganic material or an organic material May be included. The raw material solution may contain both inorganic materials and organic materials. The perovskite structure is not particularly limited as long as it has a perovskite structure, and may be a known one. Although it may be made of an inorganic material or an organic material, in the present invention, the perovskite structure is preferably made of an organic-inorganic composite material. Examples of the organic-inorganic composite material include compounds represented by the following formula (I) or the following formula (II).
CH ₃ NH ₃ M ¹ X ₃ (I)
(In the formula, M ¹ is a divalent metal ion, and X is F, Cl, Br or I.)
(R ⁶ NH ₃ ) ₂ M ¹ X ₄ (II)
(In the formula, R ⁶ is an alkyl group, alkenyl group, aralkyl group, aryl group, heterocyclic group or aromatic heterocyclic group having 2 or more carbon atoms, M ¹ is a divalent metal ion, and X is F, Cl, Br or I.)

In the present invention, the organic-inorganic composite material is preferably a substituted ammonium lead halide. Examples of the substituted ammonium lead halide include (CH ₃ NH ₃ ) PbI ₃ (methylammonium lead iodide), (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbI ₄ (phenethylammonium lead iodide), (C ₁₀ H ₇ CH ₂ NH ₃ ) ₂ PbI ₄ (naphthylmethylammonium lead iodide) and (C ₆ H ₁₃ NH ₃ ) ₂ PbI ₄ (hexylammonium lead iodide) and the like, and the formation of the perovskite structure (CH ₃ NH ₃ ) PbI ₃ (methylammonium lead iodide) is preferable from the viewpoints of availability, intramolecular symmetry, dielectric constant, dipole moment, and the like. The said substituted ammonium lead halide may be used individually by 1 type, and may be used in combination of 2 or more type.

  The raw material solution is not particularly limited as long as it does not impair the object of the present invention, and may be a known one, but in the present invention, the raw material solution is preferably a solution of the organic-inorganic composite material. The solvent of the organic-inorganic composite material is not particularly limited as long as γ-butyrolactone is contained, and may be a mixed solvent with another organic solvent or may further contain an inorganic solvent. The solvent preferably does not contain an inorganic solvent, and more preferably is composed of an aprotic solvent. The aprotic solvent preferably contained in the solvent of the raw material solution is preferably a solvent represented by the following formula (1) or formula (2).

(In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent. , R ¹ and R ² may combine to form a ring.)

(Wherein R ³ , R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom, a halogen atom or an optionally substituted hydrocarbon group or an optionally substituted heterocyclic ring. Represents a group, and any two groups selected from R ³ , R ⁴ and R ⁵ may combine to form a ring.)

  Examples of the “halogen atom” include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

Examples of the “substituent” in the present invention include a hydrocarbon group which may have a substituent, a heterocyclic group which may have a substituent, a halogen atom, a halogenated hydrocarbon group, —OR ^1a. (R ^1a represents a hydrogen atom, a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent.), —SR ^1b (R ^1b represents a hydrogen atom or a substituent. A hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent.), An acyl group which may have a substituent, an acyloxy group which may have a substituent , An alkoxycarbonyl group which may have a substituent, an aryloxycarbonyl group which may have a substituent, an alkylenedioxy group which may have a substituent, a nitro group, an amino group, a substituted amino group Group, cyano group, sulfo group, substituted silyl group, hydroxyl group, cal Xyl group, alkoxythiocarbonyl group optionally having substituent, aryloxythiocarbonyl group optionally having substituent, alkylthiocarbonyl group optionally having substituent, having substituent And an arylthiocarbonyl group which may be substituted, a carbamoyl group which may have a substituent, a substituted phosphino group, an aminosulfonyl group, an alkoxysulfonyl group, an oxo group and the like.

  Examples of the “hydrocarbon group” include a hydrocarbon group and a substituted hydrocarbon group. Examples of the hydrocarbon group include an alkyl group, an aryl group, and an aralkyl group.

  As the alkyl group, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms is preferable. Specific examples of the alkyl group include, for example, methyl, ethyl, n-propyl, 2-propyl, n-butyl, 1-methylpropyl, 2-methylpropyl, tert-butyl, n-pentyl, 1-methylbutyl, 1-methylbutyl, Ethylpropyl, tert-pentyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, n-hexyl, 1-methylpentyl, 1-ethylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-methylpentan-3-yl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl 1-ethylbutyl, 2-ethylbutyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, Decyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl, and the like. Among these, an alkyl group having 1 to 10 carbon atoms is more preferable, an alkyl group having 1 to 6 carbon atoms is more preferable, and an alkyl group having 1 to 4 carbon atoms is particularly preferable.

  As the aryl group, an aryl group having 6 to 20 carbon atoms is preferable. Specific examples of the aryl group include phenyl, indenyl, pentarenyl, naphthyl, azulenyl, fluorenyl, phenanthrenyl, anthracenyl, acenaphthylenyl, biphenylenyl, naphthacenyl, and pyrenyl. The aryl group is more preferably an aryl group having 6 to 14 carbon atoms.

  As the aralkyl group, an aralkyl group having 7 to 20 carbon atoms is preferable. Specific examples of the aralkyl group include benzyl, phenethyl, 1-phenylpropyl, 2-phenylpropyl, 3-phenylpropyl, 1-phenylbutyl, 2-phenylbutyl, 3-phenylbutyl, 4-phenylbutyl, 1-phenylbutyl, Phenylpentylbutyl, 2-phenylpentylbutyl, 3-phenylpentylbutyl, 4-phenylpentylbutyl, 5-phenylpentylbutyl, 1-phenylhexylbutyl, 2-phenylhexylbutyl, 3-phenylhexylbutyl, 4-phenylhexyl Butyl, 5-phenylhexylbutyl, 6-phenylhexylbutyl, 1-phenylheptyl, 1-phenyloctyl, 1-phenylnonyl, 1-phenyldecyl, 1-phenylundecyl, 1-phenyldodecyl, 1-phenyltridecyl Or 1 Phenyl tetradecyl, and the like. Among them, the aralkyl group is more preferably an aralkyl group having 7 to 12 carbon atoms.

  Examples of the substituent that the “hydrocarbon group” may have include the aforementioned “substituent”. Preferable specific examples of the substituted hydrocarbon group include substituted alkyl groups such as trifluoromethyl and methoxymethyl, tolyl (for example, 4-methylphenyl), xylyl (for example, 3,5-dimethylphenyl), 4-methoxy-3, A substituted aryl group or a substituted aralkyl group such as 5-dimethylphenyl or 4-methoxy-3,5-di-t-butylphenyl is exemplified.

Examples of the “heterocyclic group optionally having a substituent” include a heterocyclic group and a substituted heterocyclic group. Examples of the heterocyclic group include an aliphatic heterocyclic group and an aromatic heterocyclic group.
Examples of the aliphatic heterocyclic group include 2 to 14 carbon atoms and at least one hetero atom, preferably 1 to 3 hetero atoms such as a nitrogen atom, an oxygen atom and / or a sulfur atom. , 3 to 8 membered, preferably 5 or 6 membered monocyclic, polycyclic or condensed ring aliphatic heterocyclic group. Specific examples of the aliphatic heterocyclic group include, for example, pyrrolidyl-2-one group, piperidyl group, piperidino group, piperazinyl group, morpholino group, morpholinyl group, tetrahydrofuryl group, tetrahydropyranyl group, thiolanyl group, and succinimidyl group. Is mentioned.

  As the aromatic heterocyclic group, for example, it has 2 to 15 carbon atoms and contains at least one hetero atom, preferably 1 to 3 hetero atoms such as nitrogen atom, oxygen atom and / or sulfur atom. Examples include 3 to 8 membered, preferably 5 or 6 membered monocyclic, polycyclic or condensed heterocyclic groups, and specific examples thereof include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, Thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, furazanyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-thiadiazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, tetrazolyl, pyridyl, pyridazinyl, pyri Dinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo [b] thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, 1,2-benzisoxazolyl, benzothiazolyl, benzopyranyl, 1 , 2-Benzisothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, buteridinyl, carbazolyl, α-carbolinyl, β-carbolinyl, γ-carbolinyl, acridinyl, phenoxazinyl Phenothiazinyl, phenazinyl, phenoxathiinyl, thiantenyl, phenanthridinyl, phenanthrolinyl, indolizinyl, pyrrolo [1,2-b Pyridazinyl, pyrazolo [1,5-a] pyridyl, imidazo [1,2-a] pyridyl, imidazo [1,5-a] pyridyl, imidazo [1,2-b] pyridazinyl, imidazo [1,2-a] Pyrimidinyl, 1,2,4-triazolo [4,3-a] pyridyl, 1,2,4-triazolo [4,3-b] pyridazinyl, benzo [1,2,5] thiadiazolyl, benzo [1,2, 5] An oxadiazolyl or phthalimino group is exemplified.

  Examples of the substituent that the “heterocyclic group” may have include the aforementioned “substituent”.

In the present invention, in Formula (1), R ¹ and R ² are preferably condensed to form a ring, and in Formula (2), selected from R ³ , R ⁴ and R ⁵ It is also preferred that any two groups are bonded to form a ring. Examples of the ring formed by condensing R ¹ and R ² or the ring formed by combining any two groups selected from R ³ , R ⁴ and R ⁵ include 1 to 3 Examples thereof include a 5- to 20-membered ring which may contain a hetero atom such as an oxygen atom, a nitrogen atom or a sulfur atom as a constituent atom of the ring. Preferred rings formed include, for example, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclodecane ring, cyclododecane ring, cyclotetradecane ring, cyclopentadecane ring, cyclohexadecane ring, and cycloheptadecane ring. A monocyclic ring; a condensed ring such as a dihydronaphthalene ring, an indene ring, an indane ring, a dihydroquinoline ring, or a dihydroisoquinoline ring, and the like. These rings are usually one or two heteroatoms (for example, an oxygen atom, a nitrogen atom). Atoms or sulfur atoms). In addition, these rings may be substituted with a hydrocarbon group, a heterocyclic group, an alkoxy group, a substituted amino group, or the like. Specific examples of the hydrocarbon group and heterocyclic group include those described in the aforementioned hydrocarbon group and heterocyclic group.

  Examples of the alkoxy group may be linear, branched or cyclic, and examples thereof include an alkoxy group having 1 to 6 carbon atoms, specifically, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, n-butoxy group, 2-butoxy group, isobutoxy group, tert-butoxy group, n-pentyloxy group, 2-methylbutoxy group, 3-methylbutoxy group, 2,2-dimethylpropyloxy group, n-hexyloxy group 2-methylpentyloxy group, 3-methylpentyloxy group, 4-methylpentyloxy group, 5-methylpentyloxy group, cyclohexyloxy group, methoxymethoxy group, 2-ethoxyethoxy group and the like.

  Examples of the substituted amino group include an amino group in which one or two hydrogen atoms of the amino group are substituted with a substituent. Specific examples of the substituent of the substituted amino group include, for example, a hydrocarbon group (for example, an alkyl group), an aryl group, an aralkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, or an aralkyloxycarbonyl group. It is done. Specific examples of the amino group substituted with an alkyl group, that is, the alkyl group-substituted amino group include, for example, N-methylamino group, N, N-dimethylamino group, N, N-diethylamino group, N, N-diisopropylamino. Group, mono- or dialkylamino group of N-methyl-N-isopropylamino group or N-cyclohexylamino group. Specific examples of an amino group substituted with an aryl group, that is, an aryl group-substituted amino group include, for example, an N-phenylamino group, an N, N-diphenylamino group, an N-naphthylamino unit, and N-methyl-N-phenyl. Examples thereof include mono- or diarylamino groups such as an amino group or N-naphthyl-N-phenylamino group. Specific examples of the amino group substituted with an aralkyl group, that is, an aralkyl group-substituted amino group include, for example, a mono- or diaralkylamino group such as an N-benzylamino group or an N, N-dibenzylamino group. Moreover, di-substituted amino groups such as N-benzyl-N-methylamino group can be mentioned. Specific examples of an amino group substituted with an acyl group, that is, an acylamino group include, for example, formylamino group, acetylamino group, propionylamino group, pivaloylamino group, pentanoylamino group, hexanoylamino group, benzoylamino group, and the like. Can be mentioned. Specific examples of the amino group substituted with an alkoxycarbonyl group, that is, the alkoxycarbonylamino group include, for example, a methoxycarbonylamino group, an ethoxycarbonylamino group, an n-propoxycarbonylamino group, an n-butoxycarbonylamino group, and a tert-butoxy. Examples thereof include a carbonylamino group, a pentyloxycarbonylamino group, and a hexyloxycarbonylamino group. Specific examples of an amino group substituted with an aryloxycarbonyl group, that is, an aryloxycarbonylamino group include an amino group in which one hydrogen atom of the amino group is substituted with the aryloxycarbonyl group described above. Examples include a phenoxycarbonylamino group or a naphthyloxycarbonylamino group. Specific examples of the amino group substituted with an aralkyloxycarbonyl group, that is, an aralkyloxycarbonylamino group include a benzyloxycarbonylamino group.

  In the present invention, the organic solvent is preferably a solvent represented by the formula (1), more preferably an aliphatic cyclic ester. Examples of the aliphatic cyclic ester include lactide, glycolide, ε-caprolactone, p-dioxanone, trimethylene carbonate, trimethylene carbonate alkyl derivative, γ-valerolactone, β-butyrolactone, γ-butyrolactone, ε-decalactone, hydroxyvale Examples thereof include rate, pivalolactone, α, α-diethylpropiolactone, ethylene carbonate, ethylene oxalate, etc. Among them, it is important to use γ-butyrolactone.

  In the present invention, the raw material solution preferably contains an organometallic halide, and the raw material solution preferably contains an ammonium compound. Examples of such preferable organometallic halides and ammonium compounds include compounds represented by the above formula (I) or the above formula (II). In the present invention, a solution dissolved or dispersed in an organic solvent or an inorganic solvent such as water in the form of a complex or salt can be suitably used as the raw material solution. Examples of complex forms include acetylacetonate complexes, carbonyl complexes, ammine complexes, hydride complexes, and the like. Examples of the salt form include organic metal salts (for example, metal acetates, metal oxalates, metal citrates, etc.), sulfide metal salts, nitrate metal salts, phosphorylated metal salts, metal halide salts (for example, metal chlorides). Salt, metal bromide salt, metal iodide salt, etc.).

Moreover, you may mix additives, such as a hydrohalic acid and an oxidizing agent, with the said raw material solution. Examples of the hydrohalic acid include hydrobromic acid, hydrochloric acid, hydroiodic acid, etc. Among them, hydrobromic acid or hydroiodic acid is preferable. Examples of the oxidizing agent include hydrogen peroxide (H ₂ O ₂ ), sodium peroxide (Na ₂ O ₂ ), barium peroxide (BaO ₂ ), and benzoyl peroxide (C ₆ H ₅ CO) ₂ O _2. Peroxides, hypochlorous acid (HClO), perchloric acid, nitric acid, ozone water, organic peroxides such as peracetic acid and nitrobenzene, etc., among which hydrogen peroxide is preferred.

(Conveying process)
In the transfer step, the mist or the droplet is transferred to a substrate installed in the film forming chamber with a carrier gas. The carrier gas is not particularly limited as long as the object of the present invention is not impaired. For example, oxygen, ozone, an inert gas such as nitrogen or argon, or a reducing gas such as hydrogen gas or forming gas is preferable. Can be mentioned. Further, the type of carrier gas may be one, but it may be two or more, and a diluent gas with a reduced flow rate (for example, 10-fold diluted gas) is further used as the second carrier gas. Also good. Further, the supply location of the carrier gas is not limited to one location but may be two or more locations. The flow rate of the carrier gas is not particularly limited, but is preferably 0.01 to 20 L / min, and more preferably 1 to 10 L / min. In the case of a dilution gas, the flow rate of the dilution gas is preferably 0.001 to 2 L / min, and more preferably 0.1 to 1 L / min.

(Film formation process)
In the film forming step, a perovskite structure is formed on the base by thermally reacting the mist or droplets on the base. The thermal reaction may be performed as long as the mist or droplet reacts with heat, and the reaction conditions are not particularly limited as long as the object of the present invention is not impaired. In this step, the thermal reaction is usually performed at a temperature equal to or higher than the evaporation temperature of the solvent, but is preferably not too high (for example, 500 ° C.) or lower, more preferably 250 ° C. or lower, and most preferably 150 ° C. or lower. The lower limit is not particularly limited as long as the object of the present invention is not impaired, but is preferably 100 ° C. or higher, more preferably 110 ° C. or higher. Further, the thermal reaction may be performed under any atmosphere of vacuum, non-oxygen atmosphere, reducing gas atmosphere and oxygen atmosphere as long as the object of the present invention is not impaired. It is preferably carried out under an atmosphere. Moreover, although it may be performed under any conditions of atmospheric pressure, increased pressure, and reduced pressure, it is preferably performed under atmospheric pressure in the present invention. The film thickness can be set by adjusting the film formation time.

(Substrate)
The substrate is not particularly limited as long as it can support the perovskite film. The material of the substrate is not particularly limited as long as the object of the present invention is not impaired, and may be a known substrate, an organic compound, or an inorganic compound. It may be a porous structure. The shape of the substrate may be any shape and is effective for all shapes, for example, a plate shape such as a flat plate or a disk, a fiber shape, a rod shape, a columnar shape, a prismatic shape, A cylindrical shape, a spiral shape, a spherical shape, a ring shape and the like can be mentioned. In the present invention, a substrate is preferable. Although the thickness of a board | substrate is not specifically limited in this invention, 10 micrometers-100 mm are preferable and 100 micrometers-10 mm are more preferable.

The substrate is not particularly limited as long as it is plate-shaped and serves as a support for the perovskite film. It may be an insulator substrate, a semiconductor substrate, a metal substrate, or a conductive substrate. A substrate in which at least one of a metal film, a semiconductor film, a conductive film, and an insulating film is formed on part or all of these surfaces can also be suitably used as the substrate. . In the present invention, the substrate is preferably a glass substrate, and more preferably a glass substrate having at least one of a metal film, a semiconductor film, a conductive film and an insulating film on the surface. . Examples of the constituent metal of the metal film include one selected from gallium, iron, indium, aluminum, vanadium, titanium, chromium, rhodium, nickel, cobalt, zinc, magnesium, calcium, silicon, yttrium, strontium, and barium. Two or more kinds of metals may be mentioned. As a constituent material of the semiconductor film, for example, an elemental element such as silicon or germanium, a compound having an element of Group 3 to Group 5 or Group 13 to Group 15 of the periodic table, metal oxide, metal sulfide , Metal selenide, or metal nitride. Examples of the constituent material of the conductive film include tin-doped indium oxide (ITO), fluorine-doped indium oxide (FTO), zinc oxide (ZnO), aluminum-doped zinc oxide (AZO), and gallium-doped zinc oxide (GZO). , Tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), tungsten oxide (WO ₃ ), and the like. In the present invention, a conductive film made of a conductive oxide is preferable. An indium oxide (ITO) film is more preferable. Examples of the constituent material of the insulating film include aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), and silicon oxynitride (Si _4). O ₅ N ₃ ) and the like are mentioned, but an insulating film made of an insulating oxide is preferable, and a titania film is more preferable.

  Note that the means for forming the metal film, the semiconductor film, the conductive film, and the insulating film is not particularly limited, and may be a known means. Examples of such forming means include mist CVD, sputtering, CVD (vapor deposition), SPD (spray pyrolysis deposition), vapor deposition, ALD (atomic layer deposition), and coating ( For example, dipping, dripping, doctor blade, inkjet, spin coating, brush coating, spray coating, roll coater, air knife coating, curtain coating, wire bar coating, gravure coating, inkjet coating, and the like).

  In the present invention, the conductive film or the insulating film is preferably formed on the substrate, the conductive film is formed on the substrate, and the conductive film is further formed on the conductive film. More preferably, an insulating film is formed. In the present invention, the substrate preferably includes a tin-doped indium oxide film or a titania film, and more preferably includes a tin-doped indium oxide film and a titania film.

  In the present invention, a perovskite film may be provided directly on the substrate, or a perovskite film may be provided via another layer such as a buffer layer (buffer layer) or a stress relaxation layer. The means for forming other layers such as a buffer layer (buffer layer) and a stress relaxation layer is not particularly limited and may be a known means. In the present invention, the mist CVD method is preferable.

(Annealing process)
In the annealing process, an annealing process is performed on the film obtained in the film forming process. The annealing treatment means is not particularly limited and may be a known means, and the treatment conditions are not particularly limited. The annealing temperature is not particularly limited, but is preferably 500 ° C. or lower.

  By producing a perovskite film as described above, a perovskite film having a good perovskite structure can be obtained easily and easily. Moreover, the film thickness of the obtained perovskite film can also be easily adjusted by adjusting the film formation time.

  The perovskite film is useful for photoelectric conversion elements and the like. In the present invention, for example, when the perovskite film is used for a photoelectric conversion element or the like, the perovskite film may be used for a photoelectric conversion element or the like after using a known means such as peeling the perovskite film from the substrate or the like. You may use for a photoelectric conversion element etc. as it is.

  Hereinafter, a suitable example when the perovskite film is used for a photoelectric conversion element will be described.

  When the perovskite film is used for a photoelectric conversion element, in the method for producing a perovskite thin film, the base is preferably a transparent substrate, and more preferably a transparent conductive substrate having an electrode formed on the surface. . The transparent substrate preferably has a light transmittance measured according to JIS K 7361-1: 1997 of 10% or more, more preferably 50% or more, and most preferably 80 to 100%. .

  As the transparent substrate, any of a rigid substrate (for example, a glass substrate and an acrylic substrate) and a flexible substrate (for example, a film substrate) is preferably used. The rigid substrate is preferably a glass substrate in terms of heat resistance, and the type of glass is not particularly limited.

  Examples of the flexible substrate include polyester resin films such as polyethylene terephthalate (PET), polyethylene naphthalate, and modified polyester, polyethylene (PE) resin films, polypropylene (PP) resin films, polystyrene resin films, and cyclic olefin resins. Polyolefin resin film such as polyvinyl chloride, polyvinyl resin such as polyvinyl chloride, polyvinylidene chloride, polyvinyl acetal resin film such as polyvinyl butyral (PVB), polyether ether ketone (PEEK) resin film, polysulfone (PSF) resin film, Polyethersulfone (PES) resin film, polycarbonate (PC) resin film, polyamide resin film, polyimide resin film, acrylic resin film, triace It can be exemplified Le cellulose (TAC) resin film. In addition to these resin films, an inorganic glass film may be used as the substrate.

  When the perovskite film is used for a photoelectric conversion element, a first electrode, an electron transport layer, a semiconductor and a photoelectric conversion layer having a perovskite structure, a hole transport layer, and a second electrode are provided on the transparent substrate. Thus, a photoelectric conversion element can be manufactured.

  The first electrode is usually disposed between the transparent substrate and the photoelectric conversion layer, and is provided on one surface which is opposite to the light incident direction of the transparent substrate. However, in the present invention, the first electrode is particularly limited. Not. The first electrode preferably has a light transmittance of 60% or more, more preferably 80% or more, and most preferably 90% to 100%. The light transmittance is the same as that described in the description of the transparent substrate.

The material for forming the first electrode is not particularly limited, and may be a known material. For example, metals such as platinum, gold, silver, copper, aluminum, rhodium and indium, SnO ₂ , CdO, ZnO, CTO (CdSnO ₃ , Cd ₂ SnO ₄ , CdSnO ₄ ), In ₂ O ₃ , CdIn ₂ O ₄ And the like. Among these, gold or silver is preferable as the metal, and a grid-patterned film having openings or a film in which fine particles or nanowires are dispersed and applied is preferably used in order to impart light transmittance. . The metal oxide is preferably a composite (dope) material obtained by adding one or more selected from Sn, Sb, F and Al to the metal oxides exemplified above. More preferably, conductive metal oxides such as In ₂ O ₃ (ITO) doped with Sn, SnO ₂ doped with Sb, SnO ₂ (FTO) doped with F, and the like are mentioned. FTO is most preferred. The amount of the material forming the first electrode applied to the substrate is not particularly limited, but is preferably about 1 to 100 g per 1 m ^{2 of} the substrate.

  The means for forming the first electrode is not particularly limited as long as the object of the present invention is not impaired, and may be a known means. As a means for forming the first electrode, for example, mist CVD method, sputtering method, CVD method (vapor deposition method), SPD method (spray pyrolysis deposition method), vapor deposition method, ALD (atomic layer deposition) method, coating method, etc. (For example, dipping, dripping, doctor blade, inkjet, spin coating, brush coating, spray coating, roll coater, air knife coating, curtain coating, wire bar coating, gravure coating, inkjet coating, etc.).

  The first electrode is preferably a transparent conductive substrate provided on the transparent substrate. The average thickness of the transparent conductive substrate is not particularly limited, but is preferably in the range of about 0.1 mm to 5 mm. The surface resistance of the transparent conductive substrate is preferably 50Ω / □ or less, more preferably 20Ω / □ or less, and most preferably 10Ω / □ or less. The lower limit of the surface resistance of the transparent conductive substrate is preferably as low as possible and need not be specified. The preferable range of the light transmittance of the transparent conductive substrate is the same as the preferable range of the light transmittance of the transparent substrate.

The electron transport layer usually has a film shape (layer shape) as a short-circuit preventing means, a sealing means, and a rectifying action, and is disposed between the first electrode and the photoelectric conversion layer (semiconductor layer). The electron transport layer is preferably made of a porous structure. When the porosity of the electron transport layer is C [%] and the porosity of the semiconductor layer is D [%], D / C is preferably about 1.1 or more, for example, about 5 More preferably, it is more preferably about 10 or more. In addition, since it is preferable that the upper limit of D / C is as large as possible, it is not particularly limited, but is usually about 1000 or less. Thereby, an electron carrying layer and a semiconductor layer can exhibit those functions more suitably, respectively. The electron transport layer is usually formed on the first electrode.
More specifically, the porosity C of the electron transport layer is preferably a dense layer, more specifically, for example, preferably about 20% or less, and about 5% or less. More preferably, it is most preferably about 2% or less. Thereby, effects, such as a short circuit prevention and a rectification | straightening effect | action, can be improved more. Here, since the lower limit of the porosity of the electron transport layer is preferably as small as possible, it is not particularly limited, but is usually about 0.05% or more.

  The average thickness (film thickness) of the electron transport layer is, for example, preferably about 0.001 to 10 μm, and more preferably about 0.005 to 0.5 μm. Thereby, the said effect can be improved more.

The constituent material of the electron transport layer is not particularly limited, but an n-type semiconductor can be used. For example, in the case of inorganic substances, zinc, niobium, tin, titanium, vanadium, indium, tungsten, tantalum, zirconium, molybdenum, manganese, iron, copper, nickel, iridium, rhodium, chromium, ruthenium or oxides thereof, α-type oxidation Oxide semiconductors such as gallium, β-type gallium oxide, IGZO, nitride semiconductors such as GaN, silicon-containing semiconductors such as SiC, strontium titanate, calcium titanate, barium titanate, magnesium titanate, strontium niobate Perovskites such as these, or composite oxides or oxide mixtures thereof, or one or a combination of two or more of various metal compounds such as CdS, CdSe, TiC, Si ₃ N ₄ , SiC, and BN Can do. In the case of organic substances, fullerene or a derivative thereof (for example, phenyl-C61-butyric acid methyl ester ([60] PCBM), phenyl-C61-butyric acid n-butyl ester ([60] PCBnB), phenyl-C61-butyric acid isobutyl ester) ([60] PCBiB), phenyl-C61-butyric acid n-hexyl ester ([60] PCBH), phenyl-C61-butyric acid n-octyl ester ([60] PCBO), diphenyl-C62-bis (butyric acid methyl ester) ( Bis [60] PCBM), phenyl-C71-butyric acid methyl ester ([70] PCBM), phenyl-C85-butyric acid methyl ester ([84] PCBM), thienyl-C61-butyric acid methyl ester ([60] ThCBM), C60 Pyrrolidine tris acid, C60 pyrrolidine tri Acid ethyl ester, N-methylfulleropyrrolidine (MP-C60), (1,2-methanofullerene C60) -61-carboxylic acid, (1,2-methanofullerene C60) -61-carboxylic acid t-butyl ester) , Octaazaporphyrins, etc., perfluoro compounds in which hydrogen atoms of p-type organic semiconductor compounds are substituted with fluorine atoms (for example, perfluoropentacene or perfluorophthalocyanine), naphthalene tetracarboxylic anhydride, naphthalene tetracarboxylic diimide, perylene tetra Examples thereof include aromatic carboxylic acid anhydrides such as carboxylic acid anhydrides and perylene tetracarboxylic acid diimides, and polymer compounds containing the imidized product thereof as a skeleton.

  For example, when the hole transport layer is a p-type semiconductor and a metal is used for the electron transport layer, the work function value is smaller than that of the hole transport layer, and Schottky contact is performed. It is preferable to use what to do. Also, for example, when using a metal oxide for the electron transport layer, it is possible to use one that is in ohmic contact with the transparent conductive layer and whose energy level of the conduction band is lower than that of the porous semiconductor layer. preferable. At this time, the efficiency of electron transfer from the porous semiconductor layer (photoelectric conversion layer) to the electron transport layer can be improved by selecting an oxide as a constituent material of the electron transport layer. Especially, the titanium oxide layer which has as a main component the titanium oxide which has the electrical conductivity equivalent to a semiconductor layer (photoelectric converting layer) is preferable as an electron carrying layer. In this case, the titanium oxide layer may be either anatase-type titanium oxide or a rutile-type titanium oxide having a relatively high dielectric constant.

  The means for forming the electron transport layer is not particularly limited as long as the object of the present invention is not impaired, and may be a known means. Examples of means for forming the electron transport layer include mist CVD, sputtering, CVD (vapor phase growth), SPD (spray pyrolysis deposition), vapor deposition, ALD (atomic layer deposition), (For example, dipping, dripping, doctor blade, inkjet, spin coating, brush coating, spray coating, roll coater, air knife coating, curtain coating, wire bar coating, gravure coating, inkjet coating, etc.).

  The photoelectric conversion layer usually includes a semiconductor and a perovskite structure. Here, the perovskite structure includes the perovskite film described above. In the present invention, the perovskite thin film is preferably composed of a semiconductor layer containing the semiconductor formed on a part or all of the surface.

The semiconductor is not particularly limited and may be a known one. Examples of the semiconductor include simple elements such as silicon and germanium, compounds having elements of Group 3 to Group 5, Group 13 to Group 15 of the periodic table, metal oxides, metal sulfides, and metal selenium. Or a metal nitride. Preferred semiconductors include, for example, gallium oxide, titanium oxide, tin oxide, zinc oxide, iron oxide, tungsten oxide, zirconium oxide, hafnium oxide, and strontium oxide. Oxide, indium, cerium, yttrium, lanthanum, vanadium, niobium oxide or tantalum oxide, cadmium sulfide, zinc sulfide, lead sulfide, silver sulfide, antimony or bismuth sulfide, Examples thereof include cadmium or lead selenide, cadmium telluride, and the like. Other compound semiconductors include phosphides such as zinc, gallium, indium, and cadmium, gallium-arsenic or copper-indium selenides, copper-indium sulfides, and titanium nitrides. More specifically, specific examples of the semiconductor include Ga ₂ O ₃ , TiO ₂ , SnO ₂ , Fe ₂ O ₃ , WO ₃ , ZnO, Nb ₂ O ₅ , CdS, ZnS, PbS, and Bi ₂ S _3. , CdSe, CdTe, GaP, InP, GaAs, CuInS ₂ , CuInSe ₂ , Ti ₃ N _{4 and the} like. The semiconductors described above may be used alone, or a plurality of semiconductors may be used in combination. For example, several kinds of the above-described metal oxides or metal sulfides can be used in combination, or several kinds may be mixed and used. At this time, when a component is added as a semiconductor in addition to the metal oxide or metal sulfide, the mass ratio of the additional component to the metal oxide or metal sulfide semiconductor is preferably 30% or less.

  Examples of the shape of the semiconductor include a filler shape, a particle shape, a conical shape, a columnar shape, a tubular shape, and a flat plate shape, and are not particularly limited. Further, as the semiconductor layer, a film-like layer formed by agglomerating these filler-like, particle-like, conical, columnar, tubular, and other semiconductors may be used. In this case, a semiconductor whose surface is previously coated with a perovskite film may be used, or the perovskite film may be coated after a semiconductor layer is formed. In addition, when the shape of a semiconductor is a particle form, it is a primary particle and it is preferable that an average particle diameter is about 1-5000 nm, and it is more preferable that it is about 2-100 nm. The “average particle size” of the semiconductor is an average particle size (primary average particle size) of primary particle diameters when 100 or more samples are observed with an electron microscope.

  The method for forming the semiconductor is not particularly limited as long as the object of the present invention is not hindered, and known means can be used. Examples of the semiconductor forming means include a mist CVD method, a sputtering method, a CVD method (vapor deposition method), an SPD method (spray pyrolysis deposition method), an evaporation method, an ALD (atomic layer deposition) method, and the like. .

  The semiconductor may be surface-treated using an organic base. Examples of the organic base include diarylamine, triarylamine, pyridine, 4-t-butylpyridine, polyvinylpyridine, quinoline, piperidine, and amidine, among which pyridine, 4-t-butylpyridine, and polyvinylpyridine are preferable. . The surface treatment method is not particularly limited, and a known means may be used. For example, when the organic base is a liquid, a solution (organic base solution) dissolved in an organic solvent is prepared as it is, and the semiconductor is placed in the liquid or organic base solution at about 0 to 80 ° C. for about 1 The surface treatment of the semiconductor can be performed by immersing for 24 minutes.

  The covering means for the perovskite film is as described above. In the present invention, a substrate in which a semiconductor, an electron transport layer, and a first electrode are formed can be used for forming the perovskite film.

  The hole transport layer usually contains a polymer (preferably a conductive polymer). The hole transport layer usually has a function of supplying electrons to the perovskite film oxidized by photoexcitation to reduce the hole, and transporting holes generated at the interface with the photoelectric conversion layer to the second electrode. In addition, it is preferable that the hole transport layer is filled not only in the layered portion formed on the porous semiconductor layer but also in the voids of the porous semiconductor layer.

Examples of the constituent material of the hole transport layer include iodides such as selenium and copper iodide (CuI), cobalt complexes such as layered cobalt oxide, CuSCN, MoO ₃ , NiO, and organic hole transport materials. . Examples of the iodide include copper iodide (CuI). Examples of the layered cobalt oxide include A _x CoO ₂ (A = Li, Na, K, Ca, Sr, Ba; 0 ≦ X ≦ 1). Examples of the organic hole transport material include polythiophene derivatives such as poly-3-hexylthiophene (P3HT) and polyethylenedioxythiophene (PEDOT), 2,2 ′, 7,7′-tetrakis- (N, N— Fluorene derivatives such as di-p-methoxyphenylamine) -9,9'-spirobifluorene (spiro-MeO-TAD), carbazole derivatives such as polyvinylcarbazole, triphenylamine derivatives, diphenylamine derivatives, polysilane derivatives, polyaniline derivatives, etc. Is mentioned.

  The method for forming the hole transport layer is not particularly limited as long as the object of the present invention is not impaired, and known means can be used. Examples of the hole transport layer forming means include mist CVD, sputtering, CVD (vapor deposition), SPD (spray pyrolysis deposition), vapor deposition, ALD (atomic layer deposition), Application methods (for example, dipping, dripping, doctor blade, inkjet, spin coating, brush coating, spray coating, roll coater, air knife coating, curtain coating, wire bar coating, gravure coating, inkjet coating, etc.) can be mentioned.

  The second electrode is not particularly limited as long as it has conductivity and functions as an electrode. For example, even if it is an insulating material, if the conductive substance layer is provided on the side facing the hole transport layer and can be used as an electrode, it can be used as the second electrode. In the present invention, the second electrode preferably has good contact with the hole transport layer. The second electrode preferably has a small work function difference from the hole transport layer and is chemically stable. Such a material is not particularly limited, but is a metal thin film such as gold, silver, copper, aluminum, platinum, rhodium, magnesium, indium, carbon, carbon black, a conductive polymer, a conductive metal oxide (indium -Organic conductors such as tin composite oxide, tin oxide doped with fluorine, and the like. The average thickness of the second electrode is not particularly limited, but is preferably about 10 to 1000 nm. The surface resistance of the second electrode is not particularly limited, but is preferably low. Specifically, the range of the surface resistance of the second electrode is preferably 80Ω / □ or less, more preferably 20Ω / □. It is as follows. The lower limit of the surface resistance of the second electrode is preferably as low as possible and is not particularly limited, but may be 0.1Ω / □ or more.

  The method for forming the second electrode is not particularly limited as long as the object of the present invention is not impaired, and known means can be used. Examples of the means for forming the second electrode include mist CVD, sputtering, CVD (vapor phase growth), SPD (spray pyrolysis deposition), and vapor deposition.

  The photoelectric conversion element obtained as described above is useful as a power generation means and can be applied to various uses. Specifically, it is equipped with a photoelectric conversion element, and further useful for a photoelectric conversion apparatus having a configuration including an inverter device, an electric motor, a lighting fixture, etc. that converts a direct current output from the photoelectric conversion element into an alternating current. There is a solar cell etc. as a suitable use.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1
1. Film Forming Apparatus A mist CVD apparatus 1 used in this example will be described with reference to FIG. The mist CVD apparatus 1 includes a carrier gas source 2 for supplying a carrier gas, a flow rate adjusting valve 3 for adjusting the flow rate of the carrier gas sent out from the carrier gas source 2, and a mist generation source 4 in which a raw material solution 4a is accommodated. A container 5 for containing water 5a, an ultrasonic vibrator 6 attached to the bottom surface of the container 5, a film forming chamber 7, a supply pipe 9 connecting the mist generating source 4 to the film forming chamber 7, And a hot plate 8 installed in the membrane chamber 7. A substrate 10 is installed on the hot plate 8.

2. Preparation of raw material solution Methylammonium lead iodide was mixed with γ-butyrolactone to obtain a raw material solution. The molar concentration of methylammonium lead iodide in the solution is 0.011 mol / L.

3. Preparation of film formation The raw material solution 4a obtained in the above was accommodated in the mist generating source 4. Next, a 15 mm square glass / ITO substrate was placed on the hot plate 8 as the substrate 10, and the hot plate 8 was operated to raise the temperature in the film forming chamber 7 to 120 ° C. Next, the flow rate control valves 3a and 3b are opened, the carrier gas is supplied from the carrier gas supply means 2a and 2b, which are carrier gas sources, into the film forming chamber 7, and the atmosphere in the film forming chamber 7 is sufficiently filled with the carrier gas. After the replacement, the carrier gas flow rate was adjusted to 4 L / min. Nitrogen was used as the carrier gas.

4). Formation of Perovskite Film Next, the ultrasonic vibrator 6 was vibrated at 2.4 MHz, and the vibration was propagated to the raw material solution 4a through the water 5a, whereby the raw material solution 4a was atomized to generate the mist 4b. . The mist 4b is introduced into the film forming chamber 7 by the carrier gas through the supply pipe 9, and the mist thermally reacts in the film forming chamber 7 at 120 ° C. under atmospheric pressure. A film was formed on top. The film thickness was 1 μm and the film formation time was 20 minutes.
Next, the obtained film was annealed at 350 ° C. for 1 hour. The obtained film was a perovskite film.

(Example 2)
A perovskite film was produced in the same manner as in Example 1 except that the film formation temperature was 130 ° C. When the crystal film was identified using an X-ray diffractometer in the same manner as in Example 1, the obtained film was a perovskite film.

(Example 3)
A perovskite film was produced in the same manner as in Example 1 except that the film formation temperature was 125 ° C. When the crystal film was identified using an X-ray diffractometer in the same manner as in Example 1, the obtained film was a perovskite film.

Example 4
A perovskite film was produced in the same manner as in Example 1 except that the film formation temperature was 110 ° C. When the crystal film was identified using an X-ray diffractometer in the same manner as in Example 1, the obtained film was a perovskite film.

(Example 5)
A perovskite film was produced in the same manner as in Example 1 except that argon was used as a carrier gas instead of nitrogen. And when the crystal film was identified using the X-ray-diffraction apparatus like Example 1, the obtained film | membrane was a perovskite film | membrane.

(Comparative Example 1)
The same raw material solution as used in Example 1 was sprayed onto a glass / ITO substrate placed on a hot plate (temperature: 140 ° C.) to try to obtain a perovskite film. I didn't do it.

  The perovskite film of the present invention is useful for photoelectric conversion elements and the like, and can be used in industrial fields such as solar cells and optical sensors.

DESCRIPTION OF SYMBOLS 1 Mist CVD apparatus 2 Carrier gas source 3 Flow control valve 4 Mist generation source 4a Raw material solution 4b Mist 5 Container 5a Water 6 Ultrasonic vibrator 7 Deposition chamber 8 Hot plate 9 Supply pipe 10 Substrate

Claims (13)

  A perovskite structure precursor solution containing γ-butyrolactone as a solvent is atomized or formed into droplets, and the resulting mist or droplets are conveyed to a substrate with a carrier gas, and then the mist or droplets are thermally reacted to cause the above-described reaction. A method for producing a perovskite film, comprising forming a film of the perovskite structure on a substrate and then performing an annealing treatment.   The production method according to claim 1, wherein the precursor solution contains an organometallic halide.   The manufacturing method of Claim 1 or 2 in which a precursor solution contains an ammonium compound.   The manufacturing method in any one of Claims 1-3 in which the solvent of the precursor solution is comprised with the organic solvent.   The manufacturing method of Claim 4 with which the organic solvent is comprised with the aprotic solvent. The production method according to claim 4 or 5, wherein the organic solvent is represented by the following formula (1).
(In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent. , R ¹ and R ² may combine to form a ring.) The manufacturing method of Claim 4 or 5 in which an organic solvent contains the compound represented by following formula (2).
(Wherein R ³ , R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom, a halogen atom or an optionally substituted hydrocarbon group or an optionally substituted heterocyclic ring. Represents a group, and any two groups selected from R ³ , R ⁴ and R ⁵ may combine to form a ring.)   The manufacturing method in any one of Claims 1-7 which perform a thermal reaction at the temperature of 250 degrees C or less.   The manufacturing method according to claim 1, wherein the substrate is a glass substrate.   The manufacturing method according to claim 1, wherein the substrate includes a tin-doped indium oxide film.   The manufacturing method according to claim 1, wherein the substrate includes a titania film.   A perovskite film manufactured using the manufacturing method according to claim 1. A photoelectric conversion element comprising the perovskite film according to claim 12.