JP2022031598A - Mesoscopic photoelectric conversion element using perovskite compound and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a mesoscopic photoelectric conversion element using a perovskite compound having both output characteristics and productivity. SOLUTION: An electron transport layer 14, a mesoporous nanocrystal layer 15, an insulating spacer layer 16 and a porous hole collecting layer 17 are laminated in this order on a transparent conductive substrate 13 on which a transparent conductive layer 12 is laminated. A mesoscopic photoelectric conversion element in which all of the mesoporous nanocrystalline layer, the insulating spacer layer, and the porous hole collecting layer are filled with a halide-based perovskite compound, which is an ideal factor that is a parameter of the output current of the photoelectric conversion element. Is 1 or more and 1.3 or less. By performing the vacuum heating annealing treatment in which the annealing treatment is performed at 60 to 150 ° C. for 3 to 30 minutes under a reduced pressure of 1 to 1000 Pa, the aging time can be shortened and the output characteristics can be improved. [Selection diagram] Fig. 1

Description

The present invention relates to a mesoscopic photoelectric conversion element using a perovskite compound and a method for producing the same.

In order to meet the demand for energy sources that are environmentally sustainable and economically sustainable, research on the practical application of high-efficiency power generation systems that can be manufactured at low cost is being widely conducted. The photoelectric conversion element is a device that directly converts solar energy into electric energy by using a light absorbing material, and is a metal halogen as a compound having a perovskite type crystal structure as a light absorbing material (hereinafter referred to as "perovskite compound"). Research results have been reported that photoelectric conversion elements using compounds can achieve relatively high photoelectric conversion efficiency, and are attracting attention. Of particular interest is a mesoscopic photoelectric conversion element in which an organic-inorganic mixed perovskite compound capable of solution treatment is supported on a mesoscopic metal oxide having a large surface area.

In Patent Document 1, a hole blocking layer (electron transport layer), a mesoporous nanocrystal layer, an insulating spacer layer, and a hole collecting layer are laminated on a conductive base on which a transparent conductive layer is laminated, and supported on the mesoscopic nanocrystal layer. A mesoscopic photoelectric conversion element using a perovskite compound that imparts a photoelectric conversion function carried on the perovskite compound, that is, a photogeneration carrier generated in the photoelectric conversion layer by using the negative electrode side (conductive base) as the main incident surface. Disclosed is a mesoscopic photoelectric conversion element using a perovskite compound that efficiently collects light by taking it out to the outside, and a method for manufacturing the same.

It is disclosed that the mesoscopic photoelectric conversion element using the perovskite compound is remarkably excellent in durability among the photoelectric conversion elements using the perovskite compound (Non-Patent Document 1). Further, in the mesoscopic photoelectric conversion element using the perovskite compound, the output characteristics are improved by the aging treatment (70% RH, 40 ° C., 200h) by temperature annealing after supporting the perovskite compound on the mesoporous metal oxide layer. Is disclosed (Non-Patent Document 2).
On the other hand, it is known that a mesoscopic photoelectric conversion element using a perovskite compound causes thermal deterioration. It is considered that the cause is that lead iodide is precipitated from the perovskite compound by incorporating cations such as methylammonium and formamidinium constituting the perovskite compound into the porous hole collecting layer made of porous carbon. (Non-Patent Document 3). For this reason, the aging treatment disclosed in Non-Patent Document 2 employs a relatively low temperature of 40 ° C., which does not cause thermal deterioration, but requires a treatment time of 200 hours due to the low annealing temperature.

However, in order to realize a low-cost and high-efficiency photoelectric conversion element, there is a demand for a method for manufacturing a mesoscopic photoelectric conversion element using a perovskite compound that achieves both output characteristics and productivity by shortening the aging time.

Special Table 2016-523453 Gazette

Mei, Anyi, et al. "A hole-conductor-free, fully printable mesoscopic perovskite solar cell with high stability." science 345.6194 (2014): 295-298. Hashmi, Syed Ghufran, et al. "High performance carbon-based printed perovskite solar cells with humidity assisted thermal treatment." Journal of Materials Chemistry A 5.24 (2017): 12060-12067. Baranwal, Ajay K., et al. "Thermal degradation analysis of sealed perovskite solar cell with porous carbon electrode at 100 ° C for 7000 h." Energy Technology 7.2 (2019): 245-252.

In view of the above problems, the present invention is to provide a method for manufacturing a mesoscopic photoelectric conversion element using a perovskite compound that achieves both output characteristics and productivity by shortening the aging time.

The present invention can be carried out according to (Aspect 1) to (Aspect 7) described below.

(Aspect 1) An electron transport layer, a mesoporous nanocrystal layer, an insulating spacer layer, and a porous hole collecting layer are laminated in this order on a transparent conductive substrate on which a transparent conductive layer is laminated, and the mesoporous nanocrystals are formed. A perovskite compound composed of a halide-based organic-inorganic mixed perovskite compound represented by the following general formula (1) and a halide-based inorganic perovskite compound alone or in combination of two or more in any of the layer, the insulating spacer layer, and the porous hole collecting layer. It is a mesoscopic photoelectric conversion element filled with the above, and the ideal factor which is a parameter of the output current of the photoelectric conversion element is 1 or more and 1.3 or less.
[A] [B] [X] ₃ (1)

(Aspect 2) The mesoporous nanocrystal layer and the insulating spacer layer are formed of a metal oxide composed of a metal oxide selected from titanium oxide, zirconium dioxide, aluminum oxide, and silicon dioxide alone or in a mixture of two or more. The mesoscopic photoelectric conversion element according to (Aspect 1).

(Aspect 3) An electron transport layer, an insulating spacer layer, and a porous hole collecting layer are laminated in this order on a transparent conductive substrate on which a transparent conductive layer is laminated, and the insulating spacer layer and the porous hole are formed. A mesoscopic photoelectric conversion element in which any of the collecting layers is filled with a perovskite compound composed of a halide-based organic-inorganic mixed perovskite compound represented by the above general formula (1) alone or by mixing two or more thereof, and the photoelectric conversion element. It is a mesoscopic photoelectric conversion element characterized in that the ideal factor, which is a parameter of the output current of the above, is 1 or more and 1.3 or less.

(Aspect 4) The insulating spacer layer is formed of a metal oxide composed of a metal oxide selected from titanium oxide, zirconium dioxide, aluminum oxide, and silicon dioxide alone or in a mixture of two or more, and the insulating spacer is formed. The mesoscopic photoelectric conversion element according to (Aspect 3), wherein the density of the metal oxide layer constituting the layer is higher on the porous hole collecting layer side than on the electron transporting layer side.

(Aspect 5) A function of sequentially laminating an electron transport layer, a mesoporous nanocrystal layer, an insulating spacer layer, and a porous hole collecting layer on a transparent conductive substrate on which a transparent conductive layer is laminated by forming and firing in this order. From the layer forming step and the porous hole collecting layer side, a solution containing a precursor capable of forming the perovskite compound represented by the general formula (1) is dropwise and filled, and the porous hole collecting layer, the insulating spacer layer, and the mesoporous nano are filled. The photoelectric conversion functional layer forming step of forming a photoelectric conversion functional layer made of a perovskite compound on the crystal layer and the mesoscopic photoelectric conversion element having the photoelectric conversion functional layer formed are subjected to a reduced pressure of 1 to 1000 Pa at 60 to 150 ° C. and 3 to 30 min. This is a method for manufacturing a mesoscopic photoelectric conversion element, which comprises a vacuum heating annealing treatment step of annealing in the above.

(Aspect 6) A functional layer forming step in which an electron transport layer, an insulating spacer layer, and a porous hole collecting layer are formed and fired in this order on a transparent conductive substrate on which a transparent conductive layer is laminated, and sequentially laminated. From the porous hole collecting layer side, a solution containing a precursor that can form the perovskite compound represented by the general formula (1) is dropped and filled, and the porous hole collecting layer and the insulating spacer layer are photoelectrically converted with the perovskite compound. A photoelectric conversion functional layer forming step for forming the functional layer and a reduced pressure heating annealing step for annealing the mesoscopic photoelectric conversion element on which the photoelectric conversion functional layer is formed at 60 to 150 ° C. and 3 to 30 min under a reduced pressure of 1 to 1000 Pa. This is a method for manufacturing a mesoscopic photoelectric conversion element.

(Aspect 7) The insulating spacer layer is formed of a metal oxide composed of a metal oxide selected from titanium oxide, zirconium dioxide, aluminum oxide, and silicon dioxide, alone or in a mixture of two or more, and the insulating. The method for manufacturing a mesoscopic photoelectric conversion element according to (Aspect 6), wherein the density of the metal oxide layer constituting the spacer layer is higher on the porous hole collecting layer side than on the electron transporting layer side. be.

According to the present invention, the reduced pressure heating annealing treatment can improve the output characteristics in addition to shortening the aging time. This makes it possible to provide a method for manufacturing a mesoscopic photoelectric conversion element using a perovskite compound that achieves both output characteristics and productivity.
Since the influence of water is negligible in the vacuum heating annealing treatment, cations such as methylammonium and formamidinium constituting the perovskite compound are thermally activated by being incorporated into the porous hole collecting layer made of porous carbon. , It is possible to suppress the deterioration of the output characteristics due to the precipitation of lead iodide from the perovskite compound, and there is an effect of improving the bonding characteristics of the perovskite type semiconductor.

It is sectional drawing of the mesoscopic photoelectric conversion element which concerns on 1st Embodiment of this invention. It is sectional drawing of the mesoscopic photoelectric conversion element which concerns on 2nd Embodiment of this invention. It is a graph which shows the time-dependent change of the output characteristic by a reduced pressure heating annealing treatment condition. It is a graph which shows the relationship between the light irradiation intensity and the open circuit voltage before and after the reduced pressure heating annealing treatment of the mesoscopic photoelectric conversion element which concerns on 1st Embodiment of this invention.

Hereinafter, embodiments of the mesoscopic photoelectric conversion element of the present invention will be described with reference to FIGS. 1 and 2. The mesoscopic photoelectric conversion element of the present invention is not limited to these embodiments.

FIG. 1 is a schematic cross-sectional view of a mesoscopic photoelectric conversion element according to the first embodiment of the present invention. The mesoscopic photoelectric conversion element 1 has an electron transport layer 14, a mesoscopic nanocrystal layer 15, an insulating spacer layer 16, and a porous hole collecting layer on a transparent conductive substrate 13 in which a transparent conductive layer 12 is laminated on a transparent conductive substrate 11. It is composed of a multilayer structure in which 17s are laminated in this order. Further, the mesoporous nanocrystal layer 15, the insulating spacer layer 16, and the porous hole collecting layer 17 are filled with a perovskite compound (not shown).

FIG. 2 is a schematic cross-sectional view of the mesoscopic photoelectric conversion element according to the second embodiment of the present invention. In the mesoscopic photoelectric conversion element 2, the electron transport layer 24, the insulating spacer layer 26, and the porous hole collecting layer 27 are laminated in this order on the transparent conductive substrate 23 in which the transparent conductive layer 22 is laminated on the transparent conductive substrate 21. It is composed of a multi-layered structure. Further, the insulating spacer layer 26 and the porous hole collecting layer 27 are filled with a perovskite compound (not shown). The difference from the mesoscopic photoelectric conversion element 1 according to the first embodiment shown in FIG. 1 is that the mesoporous nanocrystal layer 15 is not included.

1. 1. Configuration of Mesoscopic Photoelectric Conversion Element (1) Transparent Conductive Substrate The transparent conductive substrate (13, 23) used in the present invention is a transparent conductive layer (12, 22) laminated on a transparent substrate (11, 21). be. Examples of the transparent substrate (11, 21) include transparent resin, optical glass, sapphire, and translucent ceramics, and any material worthy of constituting the mesoscopic photoelectric conversion element of the present invention can be used.
As the transparent resin, a material having high heat resistance, excellent chemical resistance and gas blocking property, and low cost is suitable. For example, polyolefins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), styrenes such as syndiotactic polystyrene (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PAr). ), Polysulfone (PSF), Polyethersulfone (PES), Polyetherimide (PEI), Transparent polyimide (PI), Cycloolefin copolymer (trade name: Arton), alicyclic polyolefin (trade name: Zeonoa), etc. There are polymethylmethacrylate, polymethylacrylate, polyethylene, polypropylene, cyclic polyolefin, fluorinated cyclic polyolefin, polyimide, polyvinylphenol, polyethersulfone, polyphenylene sulfide, cellulose triacetate.
The optical glass is a glass used for lenses for optical instruments, prisms, etc., which is made by strictly controlling the refractive index, Abbe number, and uniformity, and contains lead oxide (PbO) in the components. There are crown glass-based ones that do not contain and flint glass-based ones that contain lead oxide (PbO). For example, crown type (SiO ₃ -B ₂ O ₃ -R ₂ OR = Na, K), flint type (SiO ₂ -B ₂ O ₃ -PbO), barium flint type (SiO ₂ -BaO-PbO), barium. There is a crown type (SiO ₂ -B ₂ O ₃ -BaO), and there are also special compositions such as rare earths, especially lanthanum type containing a large amount of lanthanum, and phosphate type and fluoride type.
Examples of the translucent ceramics include translucent alumina (Al ₂ O ₃ ), translucent magnesia (MgO), and PLZT ((Pb, La) (Zr, Ti) O ₃ ).

(2) Transparent conductive layer As the material of the transparent conductive layer (12, 22) of the present invention, conductive metals such as platinum, gold, silver, copper, aluminum, indium, titanium, conductive carbon and highly conductive are used. Conductive organic materials typified by molecules, specifically, conductive carbon includes carbon black, carbon nanofibers, carbon nanotubes, graphene, carbon fibers, and fullerene, and conductive polymers include polyacetylene and PEDOT poly3. There are oligothiophene, polypyrrole, polyaniline, polyparaphenylene, and polyparaphenylene vinylene with 4-ethylenedioxythiophene and polystyrene sulphonic acid. Conductive metal oxides such as tin oxide, zinc oxide, conductive composite metal oxides such as indium-tin oxide (ITO), indium-zinc oxide (IZO), fluorine-doped tin oxide (FTO), Ag. There are nanowires, gold nanoparticles, silver nanoparticles, etc. Conductive metal oxides and conductive composite metal oxides are preferable in terms of having high optical transparency, and indium-tin oxide composite oxides (ITO) and indium-indium- are excellent in heat resistance and chemical stability. Zinc oxide (IZO) is particularly preferred. In the material constituting the transparent conductive layer, the composition content may be mixed with other materials, and the form and the like are not limited.
The method of forming the transparent conductive layer (12, 22) on the transparent substrate (11, 21) is not particularly limited. A sputtering method, a vapor deposition method, or a method of applying a dispersion can be selected. The light transmittance (measurement wavelength: 550 nm) of the transparent conductive substrate (13, 23) of the present invention is preferably 30% or more, more preferably 50% or more, most preferably 60% or more, and particularly 75%. % Or more is preferable. The conductivity and transparency of the transparent conductive substrate can be compatible with each other by optimizing the method of forming the transparent conductive layer, for example, by optimizing the vapor deposition time, the amount of the dispersion liquid applied, and the like.

(3) Electron transport layer The mesoscopic photoelectric conversion element (1, 2) of the present invention has an electron transport layer (14, 24) on a transparent conductive substrate (13, 23).
The electron transport layer (14, 24) has a function of transporting electrons generated in the photoelectric conversion functional layer carrying a perovskite compound (not shown) to the transparent conductive substrate (13, 23). The electron transport layer (14, 24) is formed of an electron transport material capable of exerting this function. Examples of the electron transport material include an organic material (organic electron transport material) and an inorganic material (inorganic electron transport material). Examples of the organic electron transport material include fullerene compounds such as [6,6] -Phenyl-C61-Butyric Acid Metyl Ester (PC61BM), perylene compounds such as perylenetetracarboxydiimide (PTCDI), and tetracyanoquinodimethane (TCNQ). ) And the like, or high molecular weight compounds and the like. Inorganic electron transport materials include titanium, tin, zinc, niobium, tantalum, tungsten, indium, gallium, neodymium, palladium or cadmium oxides (TIO ₂ , SnO ₂ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ and so on. There are WO ₃ , W ₂ O ₅ , In ₂ O ₃ , Ga ₂ O ₃ , Nd ₂ O ₃ , PbO, CdO).
Since the mesoscopic photoelectric conversion element (1, 2) of the present invention of the present invention is formed through a firing step, an inorganic material (inorganic electron transport material) is preferable. The electron transport layer (14, 24) can be formed by forming an inorganic electron transport material by a sputtering method, a vapor deposition method, a method of applying a dispersion, or the like.
The film thickness of the electron transport layer (14, 24) is not particularly limited, and is preferably 0.001 to 10 μm, more preferably 0.01 to 1 μm. It is also called a short-circuit prevention layer, and by providing it between the photoelectric conversion layer and the conductive substrate, it functions to prevent the reverse current generated when the photoelectric conversion layer and the conductive substrate are electrically connected.

(4) Mesoporous nanocrystal layer The mesoporous nanocrystal layer 15 of the present invention carries a perovskite compound having a photoelectric conversion function and has a function of forming a photoelectric conversion layer. The mesoporous nanocrystal layer 15 is formed of a mesoporous metal oxide capable of exerting this function. Here, the mesoporous material and the nanocrystalline material of the present invention satisfy the ordinary definitions in this field. That is, the mesoporous material is a porous material having a pore diameter of 2 to 100 nm, and the nanocrystal material is a nanomaterial having a size of 1 to 100 nm and having a crystal structure.
Examples of mesoporous metal oxides include TIM ₂ , SnO ₂ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ , WO ₃ , W ₂ O ₅ , In ₂ O ₃ , Ga ₂ O ₃ , Nd ₂ O ₃ , PbO, and so on. There are CdO, BaSnO ₃ , BaTiO ₃ , (Na _x Bi _1-x ) TiO ₃ , and the like.
The crystal granule diameter of the mesoporous nanocrystal 15 of the present invention is 20 to 100 nm, preferably 20 to 50 nm, and the thickness of the mesoporous nanocrystal layer 15 can be appropriately selected in relation to the insulating spacer layer 16 described later. For example, when the mesoporous nanocrystal layer 15 (500 nm to 700 nm) is used as the insulating spacer layer 16 (1000 nm to 3000 nm), and when the mesoporous nanocrystal layer 15 (1000 nm to 3000 nm) is used as the insulating spacer layer 16 (10 nm to 50 nm). There is.
When the mesoporous nanocrystal layer 15 (500 nm to 700 nm) and the insulating spacer layer 16 (1000 nm to 3000 nm) are used, the mesoporous nanocrystal layer 15 and the insulating spacer layer 16 are formed by a gravure coating method, a bar coating method, a printing method, or a spraying method. , Spin coating method, dip method, die coating method, etc. can be used to form a film.
When the mesoporous nanocrystal layer 15 (1000 nm to 3000 nm) and the insulating spacer layer 16 (10 nm to 50 nm) are used, the mesoporous nanocrystal layer 15 has a microporous structure formed by the printing process, but the insulating spacer layer 16 is , It becomes an amorphous structure formed by the vacuum vapor deposition method.
The insulating spacer layer 16 (10 nm to 50 nm) is a precursor that can form a perovskite compound on the mesoporous nanocrystal layer 15 from the porous hole collecting layer 17 side in the mesoscopic photoelectric conversion element (1) of the present invention. This is because the thickness of the insulating spacer layer 16 having an amorphous structure needs to be a thin film of 10 nm to 50 nm in order to drop-fill the solution containing the body.

(5) Insulation Spacer Layer The insulation spacer layer (16, 26) of the present invention is a porous hole collecting layer (holes) generated in a photoelectric conversion layer carrying a perovskite compound having a photoelectric conversion function. It is responsible for the hole transport function to transport to 17, 27).
The insulating spacer layer (16, 26) of the present invention is composed of mesoporous metal oxide. Mesoporous metal oxides include ZrO ₂ , SiO ₂ , Al _{2O 3} , CaTIO ₃ , BaTIO ₃ , PbZrO ₃ , BaTIO ₃ , PbTIO ₃ , PbZrO ₃ , _{ZnTIO 3} , BaZrO ₃ , Pb (Zr1 ₎ . ) O ₃ , (La _y Pb _1-y ) (Zr _1-x Ti _x ) O ₃ , (1-x) [Pb (Mg _1/3 Nb _2/3 ) O ₃ ] · x [PbTIO ₃ ], BiFeO ₃ , Pb (Zn _1/3 Nb _2/3 ) O ₃ , Pb (Mg _1/3 Nb _2/3 ) O ₃ , (Na _1/2 Bi _1/2 ) _{TIM 3} , (K ₁ ) _{/ 2} Bi _1/2 ) There are TiO ₃ , LiNbO ₃ , KNbO ₃ , KTaO ₃ , and the like.
The particle size of the insulating spacer layer (16) of the present invention is 10 to 100 nm, preferably 10 to 50 nm, which is smaller than that of the mesoporous nanocrystal 15 described above. This is because the density of the insulating spacer layer (16) is preferably higher than that of the mesoporous nanocrystal 15.
The film thickness of the insulating spacer layer (16) of the present invention can be appropriately selected in relation to the above-mentioned mesoporous nanocrystal layer 15. For example, when the mesoporous nanocrystal layer 15 (500 nm to 700 nm) is used as the insulating spacer layer 16 (1000 nm to 3000 nm), and when the mesoporous nanocrystal layer 15 (1000 nm to 3000 nm) is used as the insulating spacer layer 16 (10 nm to 50 nm). There is.

The insulating spacer layer (26) of the present invention has a function of supporting a perovskite compound having a hole transport function and a photoelectric conversion function to form a photoelectric conversion layer. Therefore, it is preferable that the density of the metal oxide layer constituting the insulating spacer layer (26) is higher on the porous hole collecting layer (27) side than on the electron transporting layer (24) side. As a method of providing a gradient in the density of the metal oxide layer, there is a method of sequentially laminating metal oxide fine particles having different particle sizes. Specifically, there is a method of sequentially stacking metal oxide fine particles having a large particle size on the electron transport layer (24) side and metal oxide fine particles having a small particle size on the porous hole collecting layer (27) side. be. However, the particle size of the insulating spacer layer (26) is 10 to 100 nm, preferably 10 to 50 nm. The film thickness of the insulating spacer layer (26) is 1000 nm to 4000 nm, and is preferably thicker than the film thickness of the insulating spacer layer (16) described above.

(6) Porous hole collecting layer The porous hole collecting layer (17, 27) of the present invention is composed of a porous conductive material which functions as a positive electrode. Specifically, porous metals (platinum, gold, silver, copper, aluminum, indium, titanium), porous conductive carbon (carbon black, carbon nanofibers, carbon nanotubes, graphene, carbon fiber, fullerene), porous Conductive polymers (polyacetylene, PEDOT poly 3,4-ethylenedioxythiophene, oligothiophene, polypyrrole, polyaniline, polyparaphenylene, polyparaphenylene vinylene with polystyrene sulphonic acid), porous metal oxides (tin oxide, Zinc oxide), porous conductive composite metal oxides (indium-tin oxide (ITO), indium-zinc oxide (IZO), fluorine-doped tin oxide (FTO)), Ag nanoparticles, gold nanoparticles, silver nanoparticles and so on. Porous metals, porous conductive carbon, porous metal oxides, and porous conductive composite metal oxides are particularly preferable in terms of excellent heat resistance and chemical stability.
The porous hole collecting layer (17, 27) of the present invention has a particle size of 20 to 100 nm, preferably 20 to 50 nm, and a film thickness of 50 nm to 10000 nm.

(7) Perovskite compound The photoelectric conversion functional layer of the mesoscopic photoelectric conversion element (1, 2) of the present invention contains a halide-based organic-inorganic mixed perovskite compound and a halide-based inorganic perovskite compound represented by the following general formula (1) alone or in combination of two or more. It is formed by supporting a perovskite compound composed of a mixture on a mesoporous metal oxide.
[A] [B] [X] ₃ (1)
Here, the basic structural form of the perovskite is an ABX ₃ structure, and has a three-dimensional network of vertex-shared BX ₆ octahedrons. The B component of the ABX ₃ structure is a metal cation capable of octahedral coordination of the X anion. The A cations are located in the 12 coordination holes between the BX ₆ octahedrons and are generally inorganic cations. By substituting A from an inorganic cation to an organic cation, an organic-inorganic hybrid perovskite compound is formed. The halide-based organic-inorganic mixed perovskite compound refers to an organic-inorganic mixed perovskite compound that combines desirable physical properties characteristic of both organic and inorganic components in a single molecular scale composite.

(7-1) Halide-based Organic-Inorganic Mixed Perovskite Compound The halide-based organic-inorganic mixed perovskite compound of the present invention is a compound represented by any of the following general formulas (2) to (5).
CH ₃ NH ₃ M ¹ X ₃ (2)
(In the formula, M ¹ is a divalent metal ion, and X is F, Cl, Br, I.)
R ¹ (NH ₃ ) ₂ M ¹ X ₄ (3)
(In the formula, R ¹ is an alkyl group having 2 or more carbon atoms, an alkenyl group, an aralkyl group, an aryl group, a heterocyclic group or an aromatic heterocyclic group, M1 is a divalent metal ion, and X is a divalent metal ion. F, Cl, Br, I.)
CH ₃ NH ₃ SnX ₃ (4)
In the formula, X is F, Cl, Br, I. )
R ² (NH ₃ ) ₂ SnX ₄ (5)
(In the formula, R ² is an alkyl group having 2 or more carbon atoms, an alkenyl group, an aralkyl group, an aryl group, a heterocyclic group or an aromatic heterocyclic group, and X is F, Cl, Br, I.)

The inorganic framework in the halide-based organic-inorganic mixed perovskite compound has a layer of metal halide octahedra sharing vertices. Anionic metal halide layers, such as M ¹ X ₃ ^2- , M ¹ X ₄ ^2- ), are generally divalent metals in order to balance with the positive charge from the cationic organic layer.
Specifically, the metals constituting the anionic metal halide layer of the halide-based organic-inorganic mixed perovskite compound are M ¹ example, Cu ²⁺ , Ni ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Pd ²⁺ , Ge ²⁺ , Sn ²⁺ , Pb ²⁺ , Eu ²⁺ ).
The halide constituting the anionic metal halide layer of the halide-based organic-inorganic mixed perovskite compound is a fluoride, a chloride, a bromide, an iodide, or a combination thereof. The halide is preferably bromide or iodide.

The R ¹ of the general formula (3) is a substituted or unsubstituted alkyl group having 2 to 40 carbon atoms, a linear, branched or cyclic alkyl chain, preferably 2 to 30 carbon atoms, and more preferably 2 to 30 carbon atoms. The number is 2 to 20, and the number of carbon atoms is most preferably 2 to 18. Specifically, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, isooctyl group, nonyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group and octadecyl group. Examples thereof include a group, an icosanyl group, a docosanyl group, a triacontanyl group, a tetraacontanyl group, a cyclopentyl group, a cyclohexyl group and the like.
The substituted or unsubstituted aralkyl group having 2 to 40 carbon atoms means a lower alkyl group substituted with an aryl group, the alkyl moiety is linear or branched, and the preferred carbon number is 1 to 5. It is more preferably 1, and the aryl portion preferably has 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms. Specific examples thereof include a benzyl group, a phenylethyl group, a phenylpropyl group, a naphthylmethyl group, a naphthylethyl group and the like.
The alkenyl group preferably has 3 to 30 carbon atoms, more preferably 3 to 20 carbon atoms, and most preferably 3 to 12 carbon atoms. For example, a vinyl group, a 1-propenyl group, a 2-propenyl group, a 2-butenyl group, an oleyl group, an allyl group and the like can be mentioned. Examples of the alkynyl group include acetylenyl, propargyl group, 3-pentynyl group, 2-hexylnyl and 2-decanyl.
The aryl group preferably includes a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms, for example, phenyl, naphthyl and the like. ), More preferably a phenyl group having 6 to 20 carbon atoms or a naphthyl group having 10 to 24 carbon atoms, and still more preferably a phenyl group having 6 to 12 carbon atoms or a naphthyl group having 10 to 16 carbon atoms. Examples thereof include a phenyl group, a p-chlorophenyl group, a mesityl group, a tolyl group, a xylyl group, a naphthyl group, an anthryl group, an azulenyl group, an acenaphthenyl group, a fluorenyl group, a phenanthryl group, an indenyl group, a pyrenyl group and a biphenylyl group. These groups may further have a substituent. Examples of the heterocyclic group include a pyrrolidyl group, an imidazolidyl group, a morphoryl group, an oxazolidyl group and the like. These groups may further have a substituent.
Examples of the aromatic heterocyclic group include a frill group, a thienyl group, a pyridyl group, a pyridazinyl group, a pyrimidinyl group, a pyrazinyl group, a triazinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, a quinazolinyl group, a carbazolyl group, a carbolinyl group and a diaza. Carbazolyl group Indicates that one of the arbitrary carbon atoms constituting the carboline ring of the carborinyl group is replaced with a nitrogen atom), a phthalazinyl group and the like. These groups may further have a substituent.
Specific examples of the halide-based organic-inorganic hybrid perovskite compound include CH ₃ NH ₃ PbI ₃ , CH ₃ NH ₃ PbBr ₃ , CH ₃ (CH ₂ ) nCHCH ₃ (NH ₃ ) ₂ PbI ₄ [n = 5 to 8], There are C ₆ H ₅ C ₂ H ₄ (NH ₃ ) ₂ PbBr ₄ , CH ₃ NH ₃ SnI ₃ .

(7-2) Halide-based Inorganic Perovskite Compound The halide-based inorganic perovskite compound of the present invention is represented by the following general formula (6).
CsM ² X ₃ (6)
(In the formula, M ² is a divalent metal ion, and X is F, Cl, Br, I.)

Specifically, the metal constituting the anionic metal halide layer of the halide-based inorganic perovskite compound is M ² (eg, Cu ²⁺ , Ni ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Pd. ²⁺ , Ge ²⁺ , Sn ²⁺ , Pb ²⁺ , Eu ²⁺ ).
The halide constituting the anionic metal halide layer of the halide-based inorganic perovskite compound is a fluoride, a chloride, a bromide, an iodide, or a combination thereof. The halide is preferably bromide or iodide.
Specific examples of the halide-based inorganic perovskite compound include CsSnI ₃ and CsSnBr ₃ .

The solvent for preparing the halide-based perovskite compound precursor solution used in the present invention is not particularly limited as long as it can dissolve the halide-based perovskite compound precursor. Ethers (eg, methylformate, ethylformate, propylformate, pentylformate, methylacetate, ethylacetate, pentylacetate, etc.), ketones (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, acetone, etc. Dimethyl ketone, diisobutylketone, cyclopentanone, cyclohexanone, methylcyclohexanone, etc.), ethers (eg, diethyl ether, methyl-tert-butyl ether, diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3- Dioxolane, 4-methyldioxolane, tetrahydrofuran, methyl tetrahydrofuran, anisole, phenetol, etc.), alcohols, examples, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, 2-Methyl-2-butanol, methoxypropanol, diacetone alcohol, cyclohexanol, 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, etc.), Glycol ether cellosolves (eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, triethylene glycol dimethyl ether, etc.), amide-based solvents, N, N-dimethylformamide (DMF) ), Acetamide, N, N-dimethylacetamide, etc.), nitrile-based solvent examples, acetonitrile, isobutyronitrile, propionitrile, methoxynitrile, etc.), carboat-based agents (eg, ethylene carbonate, propylene carbonate, etc.), halogenation There are hydrocarbons (eg, methylene chloride, dichloromethane, chloroform, etc.), hydrocarbons (eg, n-pentane, cyclohexane, n-hexane, benzene, toluene, xylene, etc.), dimethylsulfoxide. These may have a branched structure or an annular structure. It may have two or more functional groups of esters, ketones, ethers and alcohols, that is, -O-, -CO-, -COO-, -OH). Hydrogen atoms in the hydrocarbon moieties of esters, ketones, ethers and alcohols may be substituted with halogen atoms, especially fluorine atoms).

The halide-based organic-inorganic mixed perovskite compound and the halide-based inorganic perovskite compound of the present invention can be synthesized by a self-assembling reaction using a precursor solution. The thin film of the halide-based organic-inorganic mixed perovskite compound and the halide-based inorganic perovskite compound of the present invention is a gravure coating method after dissolving the halide-based organic-inorganic mixed perovskite compound or the halide-based inorganic perovskite compound or a mixture thereof in an organic solvent. It can be formed by a coating method such as a bar coating method, a screen printing method, a spray method, a spin coating method, a dip method, or a die coating method. Further, a film can be formed by a vacuum vapor deposition method. The film thickness of the photoelectric conversion layer of the present invention is preferably 1 to 500 nm.

Next, an embodiment of the mesoscopic photoelectric conversion element (1, 2) that exhibits the effect of the present invention is shown below as Table 1 and Examples. The evaluation of the mesoscopic photoelectric conversion element (1, 2) in the present invention was carried out according to the evaluation method described in <Example 1> below.

<Example 1>
(1) Functional layer forming step (1-1) Preparation of transparent conductive substrate FTO (fluorine-doped tin oxide) with a film thickness of 1 μm and a sheet resistance of 10 Ω / cm □ on a borosilicate glass substrate (Soda Glass) by a CVD method. ) An FTO substrate on which a film was formed was prepared. This FTO substrate was washed with water, acetone and ethanol, dried, and then organic substances were removed by irradiation with an ultraviolet ozone lamp to prepare a film-forming substrate (FTO substrate).

(1-2) Film formation and firing of electron transport layer The above-mentioned film-forming substrate (TIAA 2-propanol solution, manufactured by Aldrich) heated to 550 ° C. on a hot plate. It was spray-coated on the FTO substrate). The applied solution reacts with the moisture in the air and the organic component is discharged as CO ₂ , so that a titanium oxide layer (electron transport layer) having a thickness of about 50 nm is formed on the substrate. Then, it was calcined at 500 ° C. for 45 minutes to form an electron transport layer made of titanium oxide.

(1-3) Formation and firing of mesoporous nanocrystal layer After cooling to room temperature, a paste containing titanium oxide nanoparticles (average particle size: about 20 nm) (TIO ₂ sol manufactured by JGC Catalysts and Chemicals Co., Ltd.) is placed on the electron transport layer. A mesoporous titanium oxide nanocrystal layer made of titanium oxide having a thickness of 500 nm was formed by screen printing on the surface, heating and drying at 150 ° C. for 6 minutes, and then sintering at a maximum of 500 ° C. in an oven.

(1-4) Film formation and firing of insulating spacer layer After cooling to room temperature, a paste containing zirconium dioxide nanoparticles (average particle diameter: about 20 nm) (Zr-Nanoxide paste manufactured by SOLARONIX, using terpineol as an ink medium) Is screen-printed on a mesoporous nanocrystal layer, heated and dried at 150 ° C for 6 minutes, and then sintered in an oven at a maximum of 500 ° C to obtain an insulating spacer layer made of a 1000 nm-thick zirconium dioxide porous body. A film was formed.

(1-5) Film formation and firing of a porous hole collecting layer After cooling to room temperature, a paste containing a carbon electrode paste (particle size: about 1 to 20 nm) (Elcocurve B / SP manufactured by SOLARONIX) is applied as an insulating spacer layer. A porous hole collecting layer made of 15000 nm thick porous carbon was formed by screen printing on the surface and sintering at 400 ° C. in an oven.
As described above, the functional layer of the mesoscopic photoelectric conversion element composed of the porous hole collecting layer / insulating spacer layer / mesoporous titanium oxide nanocrystal layer / electron transport layer / FTO substrate was formed.

(2) Photoelectric conversion functional layer forming step (2-1) Preparation of halide-based perovskite compound precursor solution In a three-necked flask, 1 g of a methylamine [CH ₃ NH ₂ ] solution and 100 ml of methanol [CH ₃ OH] are placed, and nitrogen is added. Hydrogen iodide acid [HI] was added while bubbling to adjust the pH to about 3 to 4, and then the mixture was stirred with a magnetic stirrer for 1 hour. After distilling this solution with an evaporator, it was dried at 40 ° C. and repurified to synthesize methylamine iodide [CH ₃ NH ₃ I]. Next, the synthesized methylamine iodide [CH ₃ NH ₃ I] and lead iodide [PbI ₂ ] have a molar ratio of 1: 1 and a concentration of 40 wt% in γ butyrolactone [(C ₄ H ₆ O ₂ ]]. A solution of gamma butyrolactone [(C ₄ H ₆ O ₂ ]) of halide-based organic-inorganic mixed perovskite compound A [CH ₃ NH ₃ PbI ₃ ] was prepared.

(2-2) Photoelectric conversion functional layer formation Function of mesoscopic photoelectric conversion element composed of porous hole collecting layer / insulating spacer layer / mesoporous titanium oxide nanocrystal layer / electron transport layer / FTO substrate manufactured in the functional layer forming step. ^A mesoporous titanium oxide nanocrystalline layer / A halide-based perovskite compound precursor solution was infiltrated to the interface of the electron transport layer and heated to 50 ° C. to form a photoelectric conversion functional layer on the mesoporous titanium oxide nanocrystal layer of the halide-based perovskite compound precursor film.

(3) Vacuum heating annealing treatment step A mesoscopic photoelectric conversion element in which a photoelectric conversion functional layer is formed on a mesoporous titanium oxide nanocrystal layer is placed in a vacuum chamber with a heating function, and under reduced pressure heating (80 ° C., 100 Pa), 3 min, 6 min, 12 min. The output characteristics (optical current-voltage characteristics) were measured every 20 min and 30 min.

(4) Evaluation of photoelectric conversion function A pseudo-solar light source (solar simulator, Pexel) capable of irradiating class A white light (100 mW / cm ² ) as a spectral match with the standard sunlight spectrum (AM1.5G). Using PEC-L15) manufactured by Technologies, the photocurrent-voltage characteristics when irradiated with pseudo-sunlight of 100 mW / cm ² were measured. The temperature of the measurement stage was maintained at room temperature (25 ° C.) by a Pelche element (cooling module). The relationship between the light irradiation intensity and the open circuit voltage is shown.
The slope of the graph has a relationship of nkT / q. Here, n is an ideal factor (n value), k is a Boltzmann constant, T is an absolute temperature, and q is an elementary charge. Since k, T, and q are all known numbers, they are ideal from the slope of the graph. The factor (n value) was calculated. For the light irradiation intensity when calculating the ideal factor (n value), white light (100 mW / cm ² ) is dimmed using a neutral density filter (absorption type ND filter manufactured by SCHOTT), and white light (100 mW / cm ² ) is irradiated. The value of the light irradiation intensity was quantified by a Si-based photodiode detector (BS-520BK manufactured by Spectrometer Co., Ltd.) whose current value at the time is known.

<Example 2>
The mesoscopic of Example 2 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under reduced pressure heating (90 ° C., 100 Pa). A photoelectric conversion element was obtained.

<Example 3>
The mesoscopic of Example 3 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under reduced pressure heating (100 ° C., 100 Pa). A photoelectric conversion element was obtained.

<Example 4>
The mesoscopic of Example 4 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under reduced pressure heating (110 ° C., 100 Pa). A photoelectric conversion element was obtained.

<Example 5>
The mesoscopic of Example 5 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under reduced pressure heating (80 ° C., 1000 Pa). A photoelectric conversion element was obtained.

<Example 6>
After forming the electron transport layer, the mesoporous nanocrystal layer is not formed, and after cooling to room temperature, a paste containing zirconium dioxide nanoparticles (average particle size: about 20 nm) (Zr-Nanoxide paste manufactured by SOLARONIX, ink medium) is used. (Use terpineol as a material) is screen-printed on the electron transport layer, heated and dried at 150 ° C for 6 minutes, and then sintered in an oven at a maximum of 500 ° C to form a 1500 nm-thick zirconium dioxide porous body. A mesoscopic photoelectric conversion element of Example 6 was obtained in the same manner as in Example 1 except that an insulating spacer layer was formed.
As described above, the functional layer of the mesoscopic photoelectric conversion element composed of the porous hole collecting layer / insulating spacer layer / electron transport layer / FTO substrate was formed.

<Example 7>
After forming the electron transport layer, the mesoporous nanocrystal layer is not formed, and after cooling to room temperature, a paste containing zirconium dioxide nanoparticles (average particle size: about 20 nm) (Zr-Nanoxide paste manufactured by SOLARONIX, ink medium) is used. (Use terpineol as a material) is screen-printed on the electron transport layer, heated and dried at 150 ° C for 6 minutes, and then sintered in an oven at a maximum of 500 ° C to form a 1500 nm-thick zirconium dioxide porous body. An insulating spacer layer was formed. The screen printing was performed multiple times by adjusting the amount of terpineol added as an ink medium so that the density of the insulating spacer layer was higher on the porous hole collecting layer side than on the electron transporting layer side. Other than that, the mesoscopic photoelectric conversion element of Example 7 was obtained in the same manner as in Example 1.
As described above, the functional layer of the mesoscopic photoelectric conversion element composed of the porous hole collecting layer / insulating spacer layer (with difference in density) / electron transport layer / FTO substrate was formed.

<Comparative Example 1>
The mesoscopic of Comparative Example 1 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under reduced pressure heating (120 ° C., 100 Pa). A photoelectric conversion element was obtained.

<Comparative Example 2>
The mesoscopic of Comparative Example 2 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under reduced pressure heating (130 ° C., 100 Pa). A photoelectric conversion element was obtained.

<Comparative Example 3>
Comparative Example 3 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under normal pressure heating (70 ° C., 101325 Pa). A mesoscopic photoelectric conversion element was obtained.

<Comparative Example 4>
Comparative Example 4 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under normal pressure heating (90 ° C., 101325 Pa). A mesoscopic photoelectric conversion element was obtained.

<Comparative Example 5>
Comparative Example 5 in the same manner as in Example 1 except that the output characteristics (photocurrent-voltage characteristics) were measured every 3 min, 6 min, 12 min, 20 min, and 30 min under normal pressure heating (110 ° C., 101325 Pa). A mesoscopic photoelectric conversion element was obtained.

FIG. 3 is a graph in which changes over time in output characteristics are measured by changing the conditions of vacuum heating annealing treatment (Examples 1 to 4 and Comparative Examples 1 to 5). Under reduced pressure heating conditions (Examples 1 to 4; 100 Pa, 80 ° C. to 110 ° C.), the output was improved with an annealing time of 3 min. On the other hand, the output characteristics deteriorated under the same heating conditions under atmospheric pressure (Comparative Examples 3 to 5). However, the output characteristics were deteriorated under the reduced pressure heating conditions (Comparative Examples 1 and 2; 100 Pa, 120 ° C to 130 ° C).
From this result, it was clarified that the annealing time (200 h) disclosed in Non-Patent Document 2 can be significantly shortened under the reduced pressure heating condition (100 Pa, 80 ° C. to 110 ° C.).

FIG. 4 is a graph showing the relationship between the light irradiation intensity and the open circuit voltage before and after annealing in Example 2. By annealing, the ideal factor (n value) changed from 1.55 to 1.29. This suggests that the reduced pressure heating annealing treatment of the present invention improves the bonding characteristics of the perovskite type semiconductor, reduces the leakage current, and improves the output characteristics.

(5) Summary As disclosed in Non-Patent Document 3, the phenomenon that cations such as methylammonium and formamidinium constituting the perovskite compound are thermally incorporated into the porous hole collecting layer made of porous carbon is thermally taken. It is believed that the output characteristics are reduced by activation and precipitation of lead iodide from the perovskite compound. In the present invention, the output characteristics were improved under reduced pressure heating conditions (Examples 1 to 4; 100 Pa, 80 ° C. to 110 ° C.), and the output characteristics were decreased under similar heating conditions under atmospheric pressure (Comparative Examples 3 to 5). The influence of moisture can be considered as a factor that makes such a difference. That is, under the heating condition under atmospheric pressure, the thermal deterioration disclosed in Non-Patent Document 3 is accelerated by the moisture (precipitation of lead iodide is promoted), whereas under the reduced pressure heating condition, the moisture Since the influence is negligible, it is considered that the perovskite type semiconductor enjoys only the merit of improving the bonding characteristics while suppressing thermal deterioration.

The mesoscopic photoelectric conversion element of the present invention can provide a photoelectric conversion element having an excellent photoelectric conversion function and a low manufacturing cost.

1, 2 Mesoscopic photoelectric conversion element 11,21 Transparent substrate 12, 22 Transparent conductive layer 13, 23 Transparent conductive substrate 14, 24 Electron transport layer 15 Mesoporous nanocrystal layer 16, 26 Insulation spacer layer 17, 27 Porous hole collection Layer 3 current

Claims (7)

An electron transport layer, a mesoscopic nanocrystal layer, an insulating spacer layer, and a porous hole collecting layer are laminated in this order on a transparent conductive substrate on which a transparent conductive layer is laminated, and the mesoporous nanocrystal layer and the insulating spacer are formed. A mesoscopic photoelectric conversion element in which both the layer and the porous hole collecting layer are filled with a perovskite compound composed of a halide-based organic-inorganic mixed perovskite compound represented by the following general formula (1) alone or by mixing two or more thereof. The mesoscopic photoelectric conversion element is characterized in that the ideal factor, which is a parameter of the output current of the photoelectric conversion element, is 1 or more and 1.3 or less.
[A] [B] [X] ₃ (1)
In the formula, [A] is methylammonium (CH ₃ NH ₃ ⁺ ), formamidinium CH (NH ₃ ) ₂ ²⁺ , R ¹ (NH ₃ ) ₂ ²⁺ ; R ¹ is an alkyl group having 2 or more carbon atoms, alkenyl. An organic cation selected from a group, an aralkyl group, an aryl group, a heterocyclic group or an aromatic heterocyclic group, or Cs ⁺ , Rb ⁺ , Cu ⁺ , Pd ⁺ , Pt ⁺ , Ag ⁺ , Au ⁺ , Rh ⁺ or Ru. One or more inorganic cations selected from ⁺ , [B] is one or more divalent inorganic cations selected from Pb ²⁺ , Sn ²⁺ , and X is F ⁻ , Cl ⁻ , Br ⁻ ,. It is a halide anion selected ^from I-. The mesoporous nanocrystal layer and the insulating spacer layer are formed of a metal oxide composed of a metal oxide selected from titanium oxide, zirconium dioxide, aluminum oxide, and silicon dioxide alone or in a mixture of two or more. The mesoscopic photoelectric conversion element according to claim 1. An electron transport layer, an insulating spacer layer, and a porous hole collecting layer are laminated in this order on a transparent conductive substrate on which a transparent conductive layer is laminated, and any of the insulating spacer layer and the porous hole collecting layer. It is also a mesoscopic photoelectric conversion element filled with a perovskite compound composed of a halide-based organic-inorganic mixed perovskite compound represented by the above general formula (1) alone or by mixing two or more thereof, and the output current of the photoelectric conversion element. A mesoscopic photoelectric conversion element characterized in that the ideal factor as a parameter is 1 or more and 1.3 or less. The insulating spacer layer is formed of a metal oxide composed of a metal oxide selected from titanium oxide, zirconium dioxide, aluminum oxide, and silicon dioxide alone or in a mixture of two or more, and constitutes the insulating spacer layer. The mesoscopic photoelectric conversion element according to claim 3, wherein the density of the metal oxide layer is higher on the porous hole collecting layer side than on the electron transporting layer side. A functional layer forming step in which an electron transport layer, a mesoporous nanocrystal layer, an insulating spacer layer, and a porous hole collecting layer are formed and fired in this order on a transparent conductive substrate on which a transparent conductive layer is laminated. , A solution containing a precursor capable of constituting the perovskite compound represented by the general formula (1) is dropped and filled from the porous hole collecting layer side, and the porous hole collecting layer, the insulating spacer layer, and the mesoporous nanocrystal layer are filled with the perovskite. The photoelectric conversion functional layer forming step of forming the photoelectric conversion functional layer made of a compound and the mesoscopic photoelectric conversion element on which the photoelectric conversion functional layer is formed are annealed at 60 to 150 ° C. and 3 to 30 minutes under a reduced pressure of 1 to 1000 Pa. A method for manufacturing a mesoscopic photoelectric conversion element, which comprises a vacuum heating annealing treatment step. A functional layer forming step in which an electron transport layer, an insulating spacer layer, and a porous hole collecting layer are formed and fired in this order and sequentially laminated on a transparent conductive substrate on which a transparent conductive layer is laminated, and a porous hole. A solution containing a precursor capable of constituting the perovskite compound represented by the general formula (1) is dropped and filled from the collecting layer side to form a photoelectric conversion functional layer made of the perovskite compound in the porous hole collecting layer and the insulating spacer layer. This consists of a photoelectric conversion functional layer forming step and a vacuum heating annealing step of annealing the mesoscopic photoelectric conversion element on which the photoelectric conversion functional layer is formed under a reduced pressure of 1 to 1000 Pa at 60 to 150 ° C. for 3 to 30 minutes. A method for manufacturing a mesoscopic photoelectric conversion element. The insulating spacer layer is formed of a metal oxide composed of a metal oxide selected from titanium oxide, zirconium dioxide, aluminum oxide, and silicon dioxide, alone or in a mixture of two or more, and constitutes the insulating spacer layer. The method for manufacturing a mesoscopic photoelectric conversion element according to claim 6, wherein the density of the metal oxide layer is higher on the porous hole collecting layer side than on the electron transporting layer side.

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