Halogenated perovskite-type solar cell and method for manufacturing halogenated perovskite-type solar cell

Abstract

A halogenated perovskite-type solar cell (1) comprising: a first electrode (20); a hole transport layer (30) that contains a hole-transporting compound and is provided on the first electrode (20); a perovskite compound layer (40) that contains a perovskite compound and is provided on the hole transport layer (30); an electron transport layer (50) that contains an electron-transporting compound and is provided on the perovskite compound layer (40); and a second electrode (60) that is provided on the electron transport layer (50), wherein the hole transport layer (30) contains at least one of tin metal and tin oxide (SnOx1), or at least one of germanium metal and germanium oxide (GeOx2), and the perovskite compound, as a metal cation, contains tin but does not contain lead.

Description

Halogenated perovskite solar cell and method for manufacturing halogenated perovskite solar cell

[0001] The present invention relates to a halogenated perovskite solar cell and a method for manufacturing the halogenated perovskite solar cell. This application claims priority to Japanese Patent Application No. 2023-171679, filed on October 2, 2023, the contents of which are incorporated herein by reference.

[0002] Because halide perovskite solar cells contain lead, there is a strong market demand for lead-free perovskite solar cells. A promising alternative to lead-based perovskite solar cells is the tin-based perovskite solar cell (see, for example, Patent Document 1 and Non-Patent Documents 1 to 5).

[0003] International Publication No. 2019 / 139153

[0004] Nano Energy 2019, 58, 130-137J. Phys. Chem. Lett. , 9, 1682-1688, 2018J. Phys. Chem. Lett. 2019, 10, 17, 5277-5283 ACS Appl. Mater. Interfaces, 2019, 11, 34, 31105-31110 Nano Energy, 2020, 74, 104858

[0005] However, while the photoelectric conversion efficiency of lead-based perovskite solar cells is 25% to 26%, that of tin-based perovskite solar cells is only about 10%. Furthermore, although an organic polymer (PEDOT-PSS) is used as the hole transport agent, its use poses the problem of low durability.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a halogenated perovskite solar cell that achieves a photoelectric conversion efficiency higher than that of conventional solar cells and improves the durability that is a problem with tin-based perovskite solar cells that use an organic polymer as a hole transport agent, and has excellent durability, as well as a method for manufacturing a halogenated perovskite solar cell.

[0007] The present invention has the following aspects: [1] A halide perovskite solar cell comprising: a first electrode; a hole transport layer containing a hole transport compound and provided on the first electrode; a perovskite compound layer containing a perovskite compound and provided on the hole transport layer; an electron transport layer containing an electron transport compound and provided on the perovskite compound layer; and a second electrode provided on the electron transport layer, wherein the hole transport layer is a tin oxide layer containing tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２ [2] A halide perovskite solar cell comprising at least one of the tin oxide (SnO ｘ１ ) in which x1 is 1.2 to 1.9, and the germanium oxide (GeO ｘ２ ) x2 is 1.2 to 1.9. [3] The halogenated perovskite solar cell according to [1], wherein tin metal and tin oxide (SnO ｘ１ [4] The halide perovskite solar cell according to [1] or [2], further comprising a charge transport auxiliary layer containing at least one of tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２[5] The halogenated perovskite solar cell according to any one of [1] to [3], wherein the perovskite compound contains Cs or an alkylamine as an organic cation. [6] The halogenated perovskite solar cell according to [5], wherein the alkylamine contains a methylammonium halide (MA) or a formamidium halide (FA). [7] A method for manufacturing a halogenated perovskite solar cell, comprising: a hole transport layer forming step of forming a hole transport layer on a first electrode; a compound layer forming step of forming a perovskite compound layer on the hole transport layer; and an electron transport layer forming step of forming an electron transport layer on the perovskite compound layer, wherein in the hole transport layer forming step, tin metal is deposited on the first electrode and then an oxidation treatment is performed to form the hole transport layer containing tin oxide on the first electrode, or germanium metal is deposited on the first electrode and then an oxidation treatment is performed to form the hole transport layer containing germanium oxide on the first electrode. [8] The method for manufacturing a halogenated perovskite solar cell according to [7], wherein in the electron transport layer forming step, tin metal is deposited on the perovskite compound layer and then an oxidation treatment is performed to form the electron transport layer containing tin oxide on the perovskite compound layer, or germanium metal is deposited on the first electrode and then an oxidation treatment is performed to form the hole transport layer containing germanium oxide on the first electrode. [9] The method for producing a halogenated perovskite solar cell according to [7] or [8], further comprising a step of forming a charge transport auxiliary layer between the perovskite compound layer and the electron transport layer.

[0008] According to the present invention, it is possible to provide a halide perovskite solar cell that has a higher photoelectric conversion efficiency than conventional tin-based perovskite solar cells and has improved durability compared to tin-based perovskite solar cells that use an organic polymer as a hole transport agent. The effects of the present invention are believed to be due to the fact that tin metal or tin oxide, or germanium metal or germanium oxide, has good electron and hole transport properties, and that by contacting the perovskite layer, it reduces the concentration of tetravalent tin ions, which is one of the reasons for the low photoelectric conversion efficiency of tin-based perovskite, and stabilizes divalent tin ions. Furthermore, it also has the effect of planarizing the perovskite layer, which is believed to contribute to improving the photoelectric conversion efficiency when used in the tin-based perovskite solar cell.

[0009] 1 is a schematic cross-sectional view showing the structure of a halogenated perovskite solar cell according to one embodiment of the present invention. In Experimental Example 1, the P-SnO prepared by ultraviolet photoelectron spectroscopy and ultraviolet-visible light measurement was ｘ and commercially available SnO ２ 1 shows the results of measuring the valence band, band gap, and Fermi level of nanoparticles. 2 shows the results of PL measurement in Experimental Example 2. 3 shows the results of TRPL measurement in Experimental Example 2. 4 shows the J-V curve of a device with an HTL in Experimental Example 3. 5 shows the results of P-SnO ｘ 1 shows a statistical box chart of the J-V parameters of 20 individual devices with Sn metal or T-SnO and PEDOT:PSS HTLs. ｘ 1 is a scanning electron microscope image of the perovskite film after deposition. ｘ 1 is a scanning electron microscope image of the perovskite film after deposition. ｘ1 is a scanning electron microscope image of the perovskite film after deposition; 2 is a diagram showing the results of XPS measurement in Experimental Example 6; 3 is a diagram showing the results of XPS measurement in Experimental Example 6; 4 is a diagram showing the results of XPS measurement in Experimental Example 6; 5 is a diagram showing the relationship between PL intensity and decay time in Experimental Example 7; 6 is a diagram showing the relationship between PL intensity and decay time in Experimental Example 8; 7 is a diagram showing the relationship between PL intensity and decay time in Experimental Example 9; ｏｃ As a function of light intensity, in Experimental Example 10, perovskite without Sn metal deposition, perovskite containing Sn, and T-SnO ｘ 1 shows the J-V curves of S-PSCs based on perovskite containing tin oxide (SnO). Experimental Example 11 shows the relationship between photoelectric conversion efficiency and wavelength. Experimental Example 12 shows the results of an operational stability test at the maximum power point during 100 seconds of solar illumination. Experimental Example 13 shows the results of evaluating the long-term stability of an unencapsulated S-PSC. Experimental Example 14 shows the relationship between photocurrent density and voltage of an S-PSC. Experimental Example 15 shows the relationship between wavelength and photoelectric conversion efficiency of an S-PSC. Experimental Example 16 shows the relationship between the photoelectric conversion efficiency of a perovskite solar cell and tin oxide (SnO). ｘ ) is a diagram showing the relationship between X in Experimental Example 17. is a diagram showing the relationship between photocurrent density and voltage of a perovskite solar cell in Experimental Example 18. is a diagram showing the relationship between photocurrent density and voltage of a perovskite solar cell in Experimental Example 19. is a diagram showing the relationship between photocurrent density and voltage of a perovskite solar cell in Experimental Example 20. is a diagram showing the relationship between photocurrent density and voltage of a perovskite solar cell in Experimental Example 21.

[0010] The following describes embodiments of a halogenated perovskite solar cell and a method for manufacturing a halogenated perovskite solar cell according to the present invention. Note that these embodiments are specifically described to provide a better understanding of the gist of the invention, and do not limit the present invention unless otherwise specified.

[0011] [Halogenated Perovskite Solar Cell] Hereinafter, a halogenated perovskite solar cell according to one embodiment of the present invention will be described with reference to the drawings.

[0012] Figure 1 is a schematic cross-sectional view showing the structure of a halogenated perovskite solar cell of this embodiment. As shown in Figure 1, the halogenated perovskite solar cell 1 of this embodiment includes a substrate 10, a first electrode 20, a hole transport layer 30, a perovskite compound layer 40, an electron transport layer 50, and a second electrode 60. The substrate 10, the first electrode 20, the hole transport layer 30, the perovskite compound layer 40, the electron transport layer 50, and the second electrode 60 are stacked in this order. The halogenated perovskite solar cell 1 of this embodiment does not necessarily require the substrate 10.

[0013] "Substrate" The substrate 10 must maintain a certain level of hardness. Examples of the substrate 10 include a glass plate, a transparent plastic plate, a transparent plastic film, and a transparent inorganic crystal.

[0014] "First Electrode" The first electrode 20 is provided on the substrate 10. The first electrode 20 is made of a conductive material or metal that is transparent to visible light, and known materials used in ordinary photoelectric conversion elements or liquid crystal panels can be used. Examples of materials include indium tin oxide (hereinafter referred to as "ITO"), fluorine-doped tin oxide (hereinafter referred to as "FTO"), antimony-doped tin oxide (hereinafter referred to as "ATO"), indium zinc oxide, niobium titanium oxide, graphene, and metals such as gold, silver, Pt, Ti, and Cr. The first electrode 20 may be a single layer made of one of the above materials, or may be a laminate of multiple layers made of one of the above materials.

[0015] The thickness of the first electrode 20 is preferably 5 nm to 100 μm, and more preferably 50 nm to 10 μm.

[0016] A metal lead wire or the like may be used as the first electrode 20. Examples of materials for the metal lead wire include metals such as aluminum, copper, silver, gold, platinum, and nickel. Methods for providing the metal lead wire on the substrate 10 include a method in which a metal lead wire is provided on the substrate 10 by vapor deposition, sputtering, pressure bonding, or the like, and then ITO or FTO is provided thereon.

[0017] "Hole Transport Layer" The hole transport layer 30 contains a hole transport compound and is provided on the first electrode 20. The hole transport layer 30 is composed of a solid hole transport compound. The hole transport layer 30 contains tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２ That is, the hole transport layer 30 may contain only tin (Sn) metal, or may contain tin oxide (SnO ｘ１ ), and may contain only tin metal and tin oxide (SnO ｘ１ The hole transport layer 30 may contain only germanium (Ge) metal, or germanium oxide (GeO ｘ２ ), and may contain only germanium metal and germanium oxide (GeO ｘ２ The hole transport layer 30 may contain tin metal and tin oxide (SnO) at least in the region adjacent to the perovskite compound layer 40 in the thickness direction. ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２ That is, the hole transport layer 30 may contain at least one of tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２ ), or in the thickness direction, only the region adjacent to the perovskite compound layer 40 may be composed of tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２) and the other region may be composed of another solid hole transport compound. In the hole transport layer 30, the region adjacent to the perovskite compound layer 40 is referred to as a first layer 31. In the hole transport layer 30, the other region, i.e., the region adjacent to the first electrode 20 is referred to as a second layer 32.

[0018] In the hole transport layer 30, tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２ The thickness of the first layer 31 containing at least one of the above-mentioned (a) and (b) is preferably 2 nm or more and 1000 nm or less, and more preferably 10 nm or more and 100 nm or less. If the thickness of the first layer 31 is less than the lower limit, the hole collection ability decreases. If the thickness of the first layer 31 exceeds the upper limit, the light transmittance decreases and the electrical resistance increases.

[0019] When the hole transport layer 30 is composed of only the first layer 31, the hole transport layer 30 is an inorganic layer, and therefore durability at high temperatures is improved.

[0020] When the hole transport layer 30 includes the first layer 31 and the second layer 32 composed of another solid hole transport compound, the thickness of the second layer 32 is preferably 2 nm or more and 1000 nm or less, and more preferably 10 nm or more and 100 nm or less.

[0021] When the hole transport layer 30 is composed of the first layer 31 and the second layer 32, the hole transport layer 30 is an inorganic layer, and therefore durability at high temperatures is improved.

[0022] Furthermore, when the hole transport layer 30 contains tin metal or germanium metal in at least the second layer 32 adjacent to the perovskite compound layer 40 in the thickness direction, the thickness thereof is preferably 0.1 nm or more and 5 nm or less, and more preferably 0.2 nm or more and 1 nm or less.

[0023] The hole transport layer 30 is made of tin oxide (SnO ｘ１ ) In the case of nanoparticles, SnO ２ When in contact with tin perovskite, SnO ｘX1 is preferably 1.2 to 1.9, more preferably 1.5 to 1.8.

[0024] Germanium oxide (GeO ｘ２ ) X2 is preferably 1.2 to 1.9, more preferably 1.5 to 1.8.

[0025] The solid hole transport compound of the second layer 32 can be either an inorganic compound or an organic compound.

[0026] For example, in the case of an organic solid compound, the layer may have a single layer structure made of a single material, or a laminate structure made of multiple compounds. In the case of a laminate structure, a polymer material is preferably used for the organic hole transport material layer in contact with the first electrode 20. By using a polymer material with excellent film-forming properties, the surface of the perovskite compound layer 40 can be made smoother, and the photoelectric conversion characteristics can be improved.

[0027] Known organic hole transport compounds can be used as the organic hole transport material used as the solid hole transport compound in the second layer 32. Specific examples include the oxadiazole compounds disclosed in JP-B-34-5466, triphenylmethane compounds disclosed in JP-B-45-555, pyrazoline compounds disclosed in JP-B-52-4188, hydrazone compounds disclosed in JP-B-55-42380, oxadiazole compounds disclosed in JP-A-56-123544, tetraarylbenzidine compounds disclosed in JP-A-54-58445, and stilbene compounds disclosed in JP-A-58-65440 or JP-A-60-98437.

[0028] The polymer material used for the organic hole transport layer in contact with the first electrode 20 used in the laminated structure is a known hole transport polymer material, and specific examples thereof include poly(3-n-hexylthiophene), poly(3-n-octyloxythiophene), poly(9,9'-dioctyl-fluorene-co-bithiophene), poly(3,3'''-didodecyl-quaterthiophene), poly(3,6-dioctylthieno[3,2-b]thiophene), and poly(2,5-bis(3-decylthiophen-2-yl)thieno[3,2-b]thiophene). polythiophene compounds such as poly(3,4-didecylthiophene-co-thieno[3,2-b]thiophene), poly(3,6-dioctylthieno[3,2-b]thiophene-co-thieno[3,2-b]thiophene), poly(3,6-dioctylthieno[3,2-b]thiophene-co-thiophene) or poly(3,6-dioctylthieno[3,2-b]thiophene-co-bithiophene); poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly[2-methoxy-5-(3,7-dimethyloctyloxy)- polyphenylene vinylene compounds such as poly[(2-methoxy-5-(2-ethylphenyloxy)-1,4-phenylene vinylene)-co-(4,4'-biphenylene vinylene)] or poly[(2-methoxy-5-(2-ethylphenyloxy)-1,4-phenylene vinylene)-co-(4,4'-biphenylene vinylene)]; poly(9,9'-didodecylfluorenyl-2,7-diyl), poly[(9,9-dioctyl-2,7-divinylene fluorene)-alt-co-(9,10-anthracene)], poly[(9,9-dioctyl-2,7-divinylene fluorene)-alt-co-(4,4'-biphenylene)], poly[(9,9-dioctyl-2 polyfluorene compounds such as poly[(9,9-dioctyl-2,7-diyl)-co-(N,N'-diphenyl)-N,N'-dioctyl-2,7-diyl]-alt-co-(N,N'-diphenyl)-N,N'-dioctyl-2,7-diyl ...N'-di(p-hexylphenyl)-1,4-diaminobenzene], poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(N,N'-bis(4-octyloxyphenyl)benzidine-N,N'-(1,4-diphenylene)], poly[(N,N'-bis(4-octyloxyphenyl)benzidine-N,N'-(1,4-diphenylene)], poly[(N,N'-bis(4-(2-ethylhexyloxy)phenyl)benzidine-N,N'-(1,4-diphenylene)], poly[phenylimino-1,4-phenylenevinylene-2,5-dioctyloxy-1,4-phenylenevinylene-1,4-phenylene], poly[p-tolylimino-1,4-fluorene] Examples of suitable charge transport materials include polyarylamine compounds such as poly[4-(2-ethylhexyloxy)phenylenevinylene-2,5-di(2-ethylhexyloxy)phenylimino-1,4-biphenylene] and poly[4-(2-ethylhexyloxy)phenylimino-1,4-biphenylene], and polythiadiazole compounds such as poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo(2,1',3)thiadiazole] and poly[3,4-didecylthiophene-co-(1,4-benzo(2,1',3)thiadiazole]. Among these, polythiophene compounds and polyarylamine compounds are particularly preferred in terms of carrier mobility and ionization potential. Furthermore, various additives may be added to the inorganic and organic charge transport materials listed above.

[0029] Examples of additives include metal iodides such as iodine, lithium iodide, sodium iodide, potassium iodide, cesium iodide, calcium iodide, copper iodide, iron iodide, and silver iodide; quaternary ammonium salts such as tetraalkylammonium iodide and pyridinium iodide; metal bromides such as lithium bromide, sodium bromide, potassium bromide, cesium bromide, and calcium bromide; bromides of quaternary ammonium compounds such as tetraalkylammonium bromide and pyridinium bromide; metal chlorides such as copper chloride and silver chloride; metal acetates such as copper acetate, silver acetate, and palladium acetate; and metal sulfates such as copper sulfate and zinc sulfate. Examples of suitable organic solvents include metal complexes such as ferrocyanide-ferricyanide or ferrocene-ferricinium ions, sulfur compounds such as sodium polysulfide or alkylthiol-alkyl disulfides, viologen dyes, hydroquinone, ionic liquids described in Inorg. Chem. 35 (1996) 1168, such as 1,2-dimethyl-3-n-propylimidazoinium iodide, 1-methyl-3-n-hexylimidazolinium iodide, 1,2-dimethyl-3-ethylimidazolium trifluoromethanesulfonate, 1-methyl-3-butylimidazolium nonafluorobutylsulfonate, and 1-methyl-3-ethylimidazolium bis(trifluoromethyl)sulfonylimide, basic compounds such as pyridine, 4-t-butylpyridine, and benzimidazole, and lithium compounds such as lithium trifluoromethanesulfonylimide and lithium diisopropylimide.

[0030] In order to improve the conductivity, an oxidizing agent may be added to convert a part of the organic charge transport material into a radical cation.

[0031] Examples of oxidizing agents include tris(4-bromophenyl)aluminum hexachloroantimonate, silver hexafluoroantimonate, nitrosonium tetrafluoroborate, and silver nitrate. It is not necessary for the entire organic hole transport material to be oxidized by the addition of the oxidizing agent; only a portion of the material needs to be oxidized. The oxidizing agent may or may not be removed from the system after addition.

[0032] "Perovskite Compound Layer" The perovskite compound layer 40 contains a perovskite compound and is provided on the hole transport layer 30. The perovskite compound in this embodiment is a composite material of an organic compound and an inorganic compound, and may have a layered perovskite structure in which layers made of metal halide and layers in which organic cation molecules are arranged are alternately stacked. The perovskite compound is represented by the following general formula (1): X α Y β M γ (1)

[0033] In the general formula (1), X is a halogen atom, Y is an alkali metal or an alkylamine compound, M contains tin but does not contain lead, and X, Y, and M may each be composed of multiple elements, with an α:β:γ ratio of 3:1:1. Specifically, X can be a halogen atom such as chlorine, bromine, or iodine, which can be used alone or as a mixture. Y is Cs or an alkylamine. The alkylamine contains methylammonium halide (MA) or formamidium halide (FA). M is a bimetallic ion containing tin as the primary cation but not lead. That is, the perovskite compound contains tin as the metal cation but does not contain lead. The perovskite compound also contains Cs or an alkylamine as the organic cation.

[0034] “Electron Transport Layer” The electron transport layer 50 contains an electron transporting compound and is provided on the perovskite compound layer 40 .

[0035] The electron transport layer 50 contains tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２ In the region where the electron transport layer 50 and the perovskite compound layer 40 are adjacent to each other, it is preferable that the electron transport layer 50 contains at least one of tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２) is preferably contained. When the electron transport layer 50 is composed only of a layer containing an electron transport compound (hereinafter referred to as the "third layer"), the thickness of the third layer is preferably 5 nm or less, and more preferably 1 nm or less. X1 is preferably 0 to 1.9, and more preferably 1.0 to 1.8. X2 is preferably 1.0 to 1.9, and more preferably 1.0 to 1.8.

[0036] When the electron transport layer 50 includes the third layer and a layer composed of another electron transport compound (hereinafter referred to as the “fourth layer”), the thickness of the fourth layer is preferably 10 nm or more and 1000 nm or less, and more preferably 50 nm or more and 500 nm or less.

[0037] The fourth layer is a known electron transport layer, and examples thereof include fullerene-type conductive polymers, n-type small molecule organic semiconductors, graphene materials, and n-type metal oxides. SPIRO, C60, and [6,6]-phenyl-C ６１ -butylic acid methyl ester (PCBM) is used.

[0038] "Second Electrode" The second electrode 60 is formed on the electron transport layer 50. Examples of the second electrode 60 include metals such as platinum, gold, silver, copper, aluminum, rhodium, and indium; carbon-based compounds such as graphite, fullerene, and carbon nanotubes; conductive metal oxides such as ITO, FTO, and ATO; and conductive polymers such as polythiophene and polyaniline.

[0039] There is no particular limitation on the thickness of the second electrode 60. The second electrode 60 may be a single layer made of one of the materials constituting the first electrode 220 described above, or may be a laminate of multiple layers made of one of the materials described above.

[0040] "Charge Transport Assist Layer" A charge transport assist layer is formed between the perovskite compound layer 40 and the electron transport layer 50. The charge transport assist layer is a layer of tin metal and tin oxide (SnO ｘ１ ) is preferably provided as a charge transport auxiliary layer 70 containing at least one of the following.

[0041] The thickness of the charge transport assistance layer 70 is preferably 1 nm or less, more preferably 100 nm or less, and even more preferably 5 nm or more and 20 nm or less. X1 is preferably 1.0 to 1.9, and even more preferably 1.0 to 1.8.

[0042] By providing the charge transport assistance layer 70, the efficiency of charge transport from the perovskite compound layer 40 to the electron transport layer 50 is improved.

[0043] The halogenated perovskite solar cell of the present embodiment achieves a photoelectric conversion efficiency higher than that of conventional solar cells, and improves the durability that is a problem with tin-based perovskite solar cells that use an organic polymer as a hole transport agent, thereby providing a halogenated perovskite solar cell with an excellent lifespan.

[0044] [Method for manufacturing halogenated perovskite solar cell] A method for manufacturing a halogenated perovskite solar cell according to one embodiment of the present invention comprises a hole transport layer forming step (hereinafter referred to as the "first step") of forming a hole transport layer on a first electrode, a compound layer forming step (hereinafter referred to as the "second step") of forming a perovskite compound layer on the hole transport layer, and an electron transport layer forming step (hereinafter referred to as the "third step") of forming an electron transport layer on the perovskite compound layer. Hereinafter, the method for manufacturing a halogenated perovskite solar cell according to this embodiment will be described with reference to FIG. 1 .

[0045] "First Step" In the first step, the method for forming the first layer 31 includes a step of forming a precursor layer on the first electrode 20 and a step of oxidizing the precursor layer. Examples of the oxidation treatment that can be used include plasma treatment, oxidation with chemicals such as peroxides, and natural air oxidation. The method for forming the precursor layer is not particularly limited, and examples include a method for forming a thin film in a vacuum, such as vacuum deposition.

[0046] The precursor layer can be subjected to plasma treatment by a so-called plasma oxidation method, for example, by exposing the precursor layer to plasma excited at a plasma frequency of 13.56 MHz in a low-vacuum chamber containing oxygen for several seconds to obtain an oxide.

[0047] The inorganic and organic hole transport layers of the second layer 32 are formed directly on the first electrode 20. The method for producing the organic hole transport layer is not particularly limited, and examples include a method for forming a thin film in a vacuum, such as vacuum deposition, and a wet film-forming method. In consideration of production costs, the wet film-forming method is particularly preferred, and a method of coating on the first electrode 20 is preferred.

[0048] When a wet film-forming method is used, the coating method is not particularly limited and can be performed according to a known method. Examples of the coating method that can be used include dipping, spraying, wire bar coating, spin coating, roller coating, blade coating, and gravure coating. In addition, printing methods using relief printing, offset printing, gravure printing, intaglio printing, rubber printing, screen printing, and the like can also be used.

[0049] Furthermore, after providing the inorganic and organic compounds, a press treatment may be carried out. It is believed that the press treatment brings the inorganic and organic compounds into closer contact with the perovskite compound layer 4, thereby improving the photoelectric conversion characteristics.

[0050] The pressing method is not particularly limited, and examples thereof include a press molding method using a flat plate such as an IR tablet molding machine, and a roll pressing method using a roller or the like. The pressure for pressing is 10 kgf / cm. ２ More than 30 kgf / cm is preferable. ２ The above is more preferable. The time for the pressing treatment is not particularly limited, but it is preferable to perform the pressing treatment within one hour. Heat may also be applied during the pressing treatment.

[0051] During the above-mentioned pressing process, a release agent may be sandwiched between the pressing machine and the electrode. Examples of the release agent include fluororesins such as polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene copolymer, perfluoroalkoxy fluoride resin, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, and polyvinyl fluoride.

[0052] "Second Step" In the second step, a one-step precipitation method or a two-step precipitation method can be used to form the perovskite compound layer 40 containing a perovskite compound on the hole transport layer 30. The one-step precipitation method is a method of forming the perovskite compound layer 40 by applying a solution in which a metal halide (a mixture of lead halide and antimony halide) and an alkylamine halide are dissolved or dispersed in a solvent to the hole transport layer 30 and drying the solution. The two-step precipitation method is a method of forming the perovskite compound layer 40 by applying a solution in which a metal halide is dissolved or dispersed to the hole transport layer 30 and drying the solution, and then immersing the layer in a solution in which an alkylamine halide is dissolved in a solvent. The alkylamine halide preferably contains methylammonium halide (MA) or formamidium halide (FA). Of these methods, the two-step precipitation method is particularly preferred.

[0053] The solution can be applied to the hole transport layer 30 by immersion, spin coating, spraying, dipping, roller coating, air knife coating, etc. Alternatively, the perovskite compound layer 40 may be formed by precipitating a perovskite compound on the hole transport layer 30 in a supercritical fluid using carbon dioxide or the like.

[0054] In the two-step deposition method, methods for contacting the metal halide formed on the hole transport layer 30 with the solution of the halogenated alkylamine include immersion, spin coating, spraying, dipping, roller coating, and air knife coating. Deposition may also be achieved by contacting the metal halide with the halogenated alkylamine in a supercritical fluid such as carbon dioxide.

[0055] "Third Step" In the third step, the method for forming the third layer includes a step of forming a tin or germanium metal layer serving as a precursor on the perovskite compound layer 40, and a step of subjecting the metal layer to an oxidation treatment. Examples of the oxidation treatment that can be used include plasma treatment, oxidation with chemicals such as peroxides, and natural air oxidation. The method for forming the tin or germanium metal layer serving as a precursor is not particularly limited, and examples include a method of forming a thin film in a vacuum, such as vacuum deposition.

[0056] The precursor layer can be subjected to plasma treatment by a so-called plasma oxidation method, for example, by exposing the precursor layer to plasma excited at a plasma frequency of 13.56 MHz in a low-vacuum chamber containing oxygen for several seconds to obtain an oxide.

[0057] The method for forming the fourth layer is not particularly limited, and examples thereof include a method for forming a thin film in a vacuum, such as vacuum deposition.

[0058] "Fourth Step" The method for manufacturing a halogenated perovskite solar cell of the present embodiment preferably includes a step of forming a charge transport assistance layer 70 between the perovskite compound layer 40 and the electron transport layer 50 (hereinafter referred to as "fourth step").

[0059] The fourth step is performed after the second step. In the fourth step, the charge transport auxiliary layer 70 can be formed by a vapor deposition, sputtering, or coating process.

[0060] By forming the charge transport assistance layer 70 between the perovskite compound layer 40 and the electron transport layer 50, the tin ions (Sn ４＋ ) can be removed. This can improve the efficiency of charge transport from the perovskite compound layer 40 to the electron transport layer 50.

[0061] The method for manufacturing a halogenated perovskite solar cell according to the present embodiment achieves a photoelectric conversion efficiency higher than that of conventional solar cells, and improves the durability that has been a problem in tin-based perovskite solar cells that use an organic polymer as a hole transport agent, thereby providing a halogenated perovskite solar cell with an excellent lifespan.

[0062] The present invention will be explained in more detail below by way of experimental examples, but the present invention is not limited to the following experimental examples.

[0063] [Materials] The materials used in the following Experimental Examples 1 to 18, 21, and 22 are as follows: SnI ２ (99.99%, Sigma Aldrich), SnF ２ (99%, Sigma Aldrich), CsI (99.9%, Sigma Aldrich), GeI ２ (>99.8%, Sigma Aldrich), FAI (>98.0%, TCI), ethylenediammonium diiodide (EDAI ２ , 98.0%, Sigma Aldrich), diethylammonium iodide (98%, Sigma Aldrich), cesium iodide (CsI, 99.9%, Sigma Aldrich), 1,2-diaminoethane (EDA, 99%, Sigma Aldrich), Sn powder (Sigma Aldrich), PEDOT:PSS (Clevious PVP AI 4083), PCBM (99.5%, Sigma Aldrich), ICBA (1-Material), fullerene (C60, 99.9%, Sigma Aldrich), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, 99.9%, Sigma Aldrich). Aldrich), N,N-dimethylformamide (DMF, 99.8%, Sigma Aldrich), dimethyl sulfoxide (DMSO, 99.9%, Sigma Aldrich), chlorobenzene (CB, 99.8%, Sigma Aldrich). All chemicals were used without purification.

[0064] [Preparation of perovskite film] (Cs ０．０２ (FA ０．９ D.E.A. ０．１ )０．９８ ) ０．９８ EDA ０．０１ I ３ The perovskite precursor was 1M SnI ２ , 0.0196M CsI, 0.8644M FAI, 0.0960M DEAI, 0.01M EDAI ２ , 0.1M SnF ２ and 0.05 M GeI ２ The solvent used was a mixed solvent containing DMF and DMSO in a volume ratio of 4:1.

[0065] Fabrication of Perovskite Solar Cells: FTO substrates were cleaned in an ultrasonic bath using distilled water, acetone, and isopropanol for 15 minutes each. The as-cleaned FTO substrates were then plasma-treated for 5 minutes. PEDOT:PSS was spin-coated at 5,000 rpm for 50 seconds under ambient conditions to form a PEDOT:PSS film on the FTO substrate. The PEDOT:PSS film was then annealed at 180 °C for 20 minutes. Perovskite precursors were spin-coated at 5,000 rpm for 50 seconds in a nitrogen-filled glove box to form a perovskite film on the PEDOT:PSS film. 500 μL of chlorobenzene antisolvent was quickly poured onto the rotating FTO substrate in 15 seconds. The resulting perovskite film was annealed at 70 °C for 20 minutes. EDA passivation was performed by spin-coating a 0.15 mM EDA solution in chlorobenzene onto the perovskite film. Subsequently, PCBM:ICBA (1 mg / mL, 4:1 (mass ratio), chlorobenzene) was deposited. The film was then annealed at 5000 rpm for 30 seconds and then at 70°C for 10 minutes. Next, 20 nm of C60, 7 nm of BCP, and 120 nm of Ag were sequentially deposited by thermal evaporation. For samples containing Sn metal in the hole transport layer, a 1 nm Sn layer was deposited on the PEDOT:PSS. SnO was also used for the hole transport layer. ｘFor samples containing a Sn layer, the Sn layer was formed by plasma treatment (FEMTO, 50 / 60 Hz, Germany) for 2 seconds. For samples containing Sn metal in the electron transport layer on the perovskite film, a 1 nm Sn layer was deposited on the perovskite film. Also, for samples containing SnO in the electron transport layer, ｘ For the samples containing a layer, the Sn layer was formed by plasma treatment (FEMTO, 50 / 60 Hz, Germany) for 2 seconds.

[0066] [Characteristics] The methods and instruments used for characterization of perovskite solar cells are as follows: UV-visible spectrum (JASCO V-670 spectrophotometer); photoluminescence spectroscopy and time-resolved photoluminescence spectroscopy (Photonics Co., Ltd., Japan, Quantaurus-Tau); film morphology (FE-SEM, JEOL JSM-6340; AFM, JEOL-JSPM 5200); XRD pattern (Rigaku Ultima III X-ray diffractometer); X-ray photoelectron spectroscopy (XPS, JEOL JPS-9200); solar simulator (Bunmei Keiki CEP-2000SRR); IPCE spectrum (monochromatic xenon lamp spectrometer CEP-2000SRR).

[0067] [Experimental Example 1] Ultraviolet photoelectron spectroscopy (UPS) and ultraviolet-visible measurements were performed to determine whether the SnO prepared as a hole transport layer ｘ (P-SnO ｘ ) and commercially available SnO ２ Nanoparticles (C-SnO ２ The valence band, band gap, and Fermi level of C-SnO were measured. The results are shown in Figure 2. ２ P-SnO ｘ There is a large amount of Sn ２＋ This is because P-SnO ｘ This is the reason why P-SnO has a deeper Fermi level. Its ambipolar transport properties were also confirmed by field-effect transistor measurements with different plasma treatment times. ｘ When the Sn:O ratio is 1:1.77, the －３ cm ２ v－１ s －１ Thus, a higher hole mobility (FET) can be obtained.

[0068] [Experimental Example 2] EDA ２＋ A Sn perovskite film was fabricated using P-SnO as an absorption layer. ｘ To study the charge carrier dynamics in the above perovskite, we first prepared P-SnO ｘ The thickness of the P-SnO film was optimized. ｘ has been developed to synthesize P-SnO perovskites, characterized by strong photoluminescence (PL) quenching, shorter PL lifetime, and high device performance. ｘ Then, PL and TRPL measurements showed that P-SnO ｘ The upper perovskite exhibits faster carriers (Fig. 3, Fig. 4). X-ray diffraction measurements confirmed that the nucleation and growth of the perovskite film were not affected by the different HTLs. Contact angle measurements also confirmed that the P-SnO ｘ Preparation conditions and C-SnO ２ This confirms the results obtained by high-temperature annealing (180°C) of PEDOT:PSS. Note that no change in the morphology of the perovskite was observed by scanning electron microscopy.

[0069] [Experimental Example 3] Figure 5 shows the J-V curves of devices with various HTLs. ｘ The S-PSC with －２ Short circuit current density (J ｓｃ ), 0.70V open circuit photovoltage (V ｏｃ ), and a fill factor (FF) of 0.74. The PCE is 10.89 ± 0.51%, which is comparable to that of PEDOT:PSS-based S-PSCs (10.39 ± 0.72%).

[0070] [Experimental Example 4] FIG. ｘ Figure 1 shows statistical box charts of J-V parameters of 20 individual devices with P-SnO and PEDOT:PSS HTL. ｘ On the V-based device, ｏｃincreases, FF increases, and J ｓｃ decreases and performance improves slightly. ｏｃ The increase in J is thought to be responsible for the delay in charge recombination, and the slightly decreased J ｓｃ is related to the light transmittance. ２ The base device is V ｏｃ is 0.51V, J ｓｃ is 20.65mAcm －２ , FF is 0.31, showing poor performance (2.79±0.40%). ２ indicates that the material is not suitable for HTL because it has strong n-type properties.

[0071] [Experimental Example 5] In order to further improve the device performance, a SnO ｘ (T-SnO ｘ First, the plasma treatment time was optimized. From the XPS results, it was found that Sn metal was converted into Sn with only 2 seconds of plasma treatment. ４＋ (SnO ２ ) can be converted into Sn. ２＋ No signal was detected. This is because T-SnO ｘ is SnO ２ This means that the film is a mixture of Sn metal and T-SnO, which is thought to be beneficial for electron transport and perovskite protection. ｘ It was found that there was little effect on the perovskite film after deposition. ｘ This is because the characteristic diffraction peaks of Sn or T-SnO on the perovskite film were not observed. ｘ This may be explained by the thin thickness of the SnO. ｘ was confirmed to be uniformly distributed on the perovskite film (Figs. 7 to 9).

[0072] [Experimental Example 6] The change in the valence state of Sn on the perovskite film was identified by XPS measurement. As shown in Figures 10 to 12, the two split peaks of Sn are ２＋and Sn ４＋ In the case of perovskite without Sn metal deposition, Sn ４＋ / Sn ２＋ The ratio of Sn to Sn is 0.96. ２＋ As the content of Sn increases, ４＋ / Sn ２＋ The ratio drops to 0.70. This is because SnO is ４＋ Sn ２＋ It is thought that this is because Sn ０ Furthermore, the peak of Sn after plasma oxidation of Sn metal was also observed. ４＋ As the content increases, Sn becomes T-SnO ｘ The transition to T-SnO was confirmed. ｘ layer, and the T-SnO ｘ The layer forms a perovskite protective layer.

[0073] [Experimental Example 7] Sn metal is T-SnO ｘ After the perovskite was converted to T-SnO, a decrease in PL intensity and decay time was observed. ｘ Fast charge transfer to the cation was demonstrated (Figure 13).

[0074] [Experimental Example 8] Perovskite / fullerene and perovskite / T-SnO ｘ The relationship between PL intensity and decay time for the PL and TRPL of fullerene is shown in Figure 14. ｘ It was found that the introduction of this material made it possible to collect and transport electrons at high speeds.

[0075] [Experimental Example 9] In FIG. ｏｃ as a function of light intensity. ｘ The devices containing ZnSe exhibited lower slopes of 1.46 KbT / q and 1.25 KbT / q than the perovskite-based devices (1.65 KbT / q).

[0076] [Experimental Example 10] FIG. 16 shows the results of the perovskite without Sn metal deposition, the perovskite containing Sn, and the T-SnO ｘFigure 1 shows the J-V curves of S-PSCs based on perovskite containing Sn. The photoelectric conversion efficiency of the perovskite without Sn metal deposition was 10.64±0.36%. After Sn metal deposition, the photoelectric conversion efficiency of the device increased (12.09±0.51%). This is mainly due to the J ｓｃ This is thought to be due to an increase in the trap density. ｘ The photoelectric conversion efficiency was 13.08±0.33%.

[0077] Experimental Example 11 FIG. 17 shows the relationship between photoelectric conversion efficiency and wavelength.

[0078] Example 12 The results of operational stability tests at maximum power point during 100 seconds of solar illumination are shown in Figure 18. All three devices were found to exhibit stable power output.

[0079] Experimental Example 13: The long-term stability of unencapsulated S-PSC was evaluated. ｘ It was found that the S-PSCs with Sn metal deposition exhibited a narrower performance distribution for 10 individual cells than the devices without Sn metal deposition (FIG. 19).

[0080] [Experimental Example 14] FTO / P-SnO ｘ / Perovskite / T-SnO ｘ We fabricated an S-PSC with a structure of ZnO / fullerene / BCP / Ag. Figure 20 shows the relationship between the photocurrent density and voltage of this S-PSC.

[0081] [Experimental Example 15] The relationship between wavelength and photoelectric conversion efficiency of the S-PSC obtained in Experimental Example 13 is shown in Figure 21. The photoelectric conversion efficiency was 14.09% (13.5±0.32%), and V ｏｃ This is thought to have been achieved by a further increase in

[0082] [Experimental Example 16] Tin oxide (SnO ｘ The perovskite solar cell was fabricated in the same manner as the above-described perovskite solar cell, except that in the above-described formula (1), X was set to 1.75 to 2.2. ｘThe X in the formula (1) was adjusted by changing the oxidation time of tin. The photoelectric conversion efficiency of the obtained perovskite solar cell and the tin oxide (SnO ｘ 22 shows the relationship between X and the photoelectric conversion efficiency. The results shown in FIG. 22 show that when X is in the range of 1.75 to 1.9, the photoelectric conversion efficiency is excellent. On the other hand, when X exceeds 1.9, the photoelectric conversion efficiency is poor.

[0083] [Experimental Example 17] Tin oxide (SnO ｘ A perovskite solar cell was fabricated in the same manner as in the above-described method for manufacturing a perovskite solar cell, except that in the above-described method, X was set to 1.4. ｘ The value of X in the above formula was adjusted by changing the oxidation time of tin. ｘ We fabricated a perovskite solar cell that had an organic hole transport layer containing [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) adjacent to a hole transport layer containing 2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) between the electrode and the hole transport layer. The organic hole transport layer was formed by coating or vapor deposition. Figure 23 shows the relationship between the photocurrent density and voltage of the perovskite solar cell. The results shown in Figure 23 indicate that the perovskite solar cell with the organic hole transport layer had lower resistance.

[0084] [Experimental Example 18] [Materials] The materials used in the following Experimental Example 18 are as follows: SnI ２ (99.99%, Sigma Aldrich), SnF ２ (99%, Sigma Aldrich), CsI (99.9%, Sigma Aldrich), GeI ２ (>99.8%, Sigma Aldrich), FAI (>98.0%, TCI), ethylenediammonium diiodide (EDAI ２, 98.0%, Sigma Aldrich), diethylammonium iodide (98%, Sigma Aldrich), cesium iodide (CsI, 99.9%, Sigma Aldrich), 1,2-diaminoethane (EDA, 99%, Sigma Aldrich), Sn powder (Sigma Aldrich), PEDOT:PSS (Clevious PVP AI 4083), PCBM (99.5%, Sigma Aldrich), ICBA (1-Material), fullerene (C60, 99.9%, Sigma Aldrich), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, 99.9%, Sigma Aldrich). Aldrich), N,N-dimethylformamide (DMF, 99.8%, Sigma Aldrich), dimethyl sulfoxide (DMSO, 99.9%, Sigma Aldrich), chlorobenzene (CB, 99.8%, Sigma Aldrich). All chemicals were used without purification.

[0085] [Preparation of perovskite film] (Cs ０．０２ (FA ０．９ D.E.A. ０．１ ) ０．９８ ) ０．９８ EDA ０．０１ I ３ The perovskite precursor was 1M SnI ２ , 0.0196M CsI, 0.8644M FAI, 0.0960M DEAI, 0.01M EDAI ２ , 0.1M SnF ２ and 0.05 M GeI ２ The solvent used was a mixed solvent containing DMF and DMSO in a volume ratio of 4:1.

[0086] Fabrication of Perovskite Solar Cells: FTO substrates were cleaned in an ultrasonic bath using distilled water, acetone, and isopropanol for 15 minutes each. The as-cleaned FTO substrates were then plasma-treated for 5 minutes. PEDOT:PSS was spin-coated at 5,000 rpm for 50 seconds under ambient conditions to form a PEDOT:PSS film on the FTO substrate. The PEDOT:PSS film was then annealed at 180 °C for 20 minutes. Perovskite precursors were spin-coated at 5,000 rpm for 50 seconds in a nitrogen-filled glove box to form a perovskite film on the PEDOT:PSS film. 500 μL of chlorobenzene antisolvent was quickly poured onto the rotating FTO substrate in 15 seconds. The resulting perovskite film was annealed at 70 °C for 20 minutes. EDA passivation was performed by spin-coating a 0.15 mM EDA solution in chlorobenzene onto the perovskite film. Subsequently, PCBM:ICBA (1 mg / mL, 4:1 (mass ratio), chlorobenzene) was deposited. The film was then annealed at 5000 rpm for 30 seconds and then at 70°C for 10 minutes. Next, 20 nm of C60, 7 nm of BCP, and 120 nm of Ag were sequentially deposited by thermal evaporation. For samples containing Ge metal in the hole transport layer, a 1 nm Ge layer was deposited on the PEDOT:PSS. GeO was also deposited as a hole transport layer. ｘ For samples containing a Ge layer, the Ge layer was formed by plasma treatment (FEMTO, 50 / 60 Hz, Germany) for 2 seconds. For samples containing Ge metal in the electron transport layer on the perovskite film, a 1 nm Ge layer was deposited on the perovskite film. Also, the electron transport layer contained GeO. ｘ For samples containing a layer, the Ge layer was formed by plasma treatment (FEMTO, 50 / 60 Hz, Germany) for 2 seconds.

[0087] The relationship between photocurrent density and voltage of perovskite solar cells is shown in Figure 24. The results shown in Figure 24 indicate that perovskite solar cells with a hole transport layer containing germanium (Ge) have low resistance. In other words, the efficiency was improved by evaporating germanium metal.

[0088] [Experimental Example 19] Tin oxide (SnO ｘ The relationship between photocurrent density and voltage for a perovskite solar cell having a hole transport layer containing tin oxide (SnO) and a perovskite solar cell having a hole transport layer containing germanium (Ge) is shown in FIG. 25. From the results shown in FIG. 25, it can be seen that the perovskite solar cell having a hole transport layer containing germanium (Ge) has a higher photocurrent density than the perovskite solar cell having a hole transport layer containing tin oxide (SnO). ｘ The results showed that the resistance of the perovskite solar cell was lower than that of a perovskite solar cell with a hole transport layer containing tin and germanium.

[0089] Experimental Example 20 A perovskite solar cell was fabricated using the same method as the perovskite solar cell described above, except that the thickness of the hole transport layer was set to 0.1 nm to 1.0 nm. The plasma oxidation process used to form the hole transport layer was performed once. Figure 26 shows the relationship between the photocurrent density and voltage of the perovskite solar cell. The results shown in Figure 26 indicate that a perovskite solar cell with a hole transport layer thickness of 0.3 nm had the lowest resistance. This means that a thinner hole transport layer resulted in higher efficiency.

[0090] Experimental Example 21: Perovskite solar cells were fabricated using the same method as the perovskite solar cell described above, except that the thickness of the hole transport layer was set to 0.1 nm to 1.0 nm. Oxidation by plasma treatment was performed twice when forming the hole transport layer. Figure 27 shows the relationship between photocurrent density and voltage for perovskite solar cells. The results shown in Figure 27 indicate that perovskite solar cells with a hole transport layer thickness of 0.5 nm have the lowest resistance. This indicates that the introduction of germanium improves efficiency.

[0091] As described above, in the halogenated perovskite solar cell of the present invention, the hole transport layer contains tin metal and tin oxide (SnO ｘ１) can effectively reduce trap density and accelerate electron transport. Therefore, the photoelectric conversion efficiency of the perovskite solar cell is improved to 13.08±0.33%, and the initial photoelectric conversion efficiency can be maintained even after storage for 50 days under a nitrogen atmosphere. Furthermore, the electron transport layer contains at least one of tin metal or tin oxide (SnO ｘ１ ), the photoelectric conversion efficiency was 14.09% (13.5±0.32%), which exceeded the photoelectric conversion efficiency (13.39±0.72%) of PEDOT:PSS-based perovskite solar cells.

[0092] REFERENCE SIGNS LIST 1 halogenated perovskite solar cell 10 substrate 20 first electrode 30 hole transport layer 31 first layer 32 second layer 40 perovskite compound layer 50 electron transport layer 60 second electrode 70 charge transport auxiliary layer

Claims

1. A halide perovskite solar cell comprising a first electrode, a hole transport layer containing a hole transport compound and provided on the first electrode, a perovskite compound layer containing a perovskite compound and provided on the hole transport layer, an electron transport layer containing an electron transport compound and provided on the perovskite compound layer, and a second electrode provided on the electron transport layer, wherein the hole transport layer is a tin oxide layer containing tin metal and tin oxide (SnO ｘ１ ), or at least one of germanium metal and germanium oxide (GeO ｘ２ ) wherein the perovskite compound contains tin but does not contain lead as a metal cation.

2. The tin oxide (SnO ｘ１ ) in which x1 is 1.2 to 1.9, and the germanium oxide (GeO ｘ２ 2. The halogenated perovskite solar cell according to claim 1, wherein x2 is 1.2 to 1.

9.

3. Between the perovskite compound layer and the electron transport layer, tin metal and tin oxide (SnO ｘ１ 2. The halide perovskite solar cell according to claim 1 , further comprising a charge transport auxiliary layer comprising at least one of:

4. The hole transport layer includes a first layer adjacent to the perovskite compound layer side and a second layer adjacent to the first electrode side, and the first layer is made of tin metal and tin oxide (SnO ｘ１ ) or at least one of germanium metal and germanium oxide (GeO ｘ２ 2. The halogenated perovskite solar cell according to claim 1 , comprising at least one of:

5. The halogenated perovskite solar cell according to claim 1, wherein the perovskite compound contains Cs or an alkylamine as an organic cation.

6. The halogenated perovskite solar cell of claim 5, wherein the alkylamine comprises a methylammonium halide (MA) or a formamidium halide (FA).

7. A method for producing a halogenated perovskite solar cell, comprising: a hole transport layer forming step of forming a hole transport layer on a first electrode; a compound layer forming step of forming a perovskite compound layer on the hole transport layer; and an electron transport layer forming step of forming an electron transport layer on the perovskite compound layer, wherein in the hole transport layer forming step, tin metal is deposited on the first electrode and then an oxidation treatment is performed to form the hole transport layer containing tin oxide on the first electrode, or germanium metal is deposited on the first electrode and then an oxidation treatment is performed to form the hole transport layer containing germanium oxide on the first electrode.

8. The method for producing a halogenated perovskite solar cell according to claim 7, wherein in the electron transport layer formation step, tin metal is deposited on the perovskite compound layer and then an oxidation treatment is performed to form the electron transport layer containing tin oxide on the perovskite compound layer, or germanium metal is deposited on the first electrode and then an oxidation treatment is performed to form the hole transport layer containing germanium oxide on the first electrode.

9. The method for producing a halogenated perovskite solar cell according to claim 7, further comprising the step of forming a charge transport auxiliary layer between the perovskite compound layer and the electron transport layer.

Images