Perovskite crystal, precursor solution, perovskite layer, perovskite cell, preparation method, photovoltaic module and electrical apparatus

Abstract

A perovskite crystal, a precursor solution, a perovskite layer, a perovskite cell, a preparation method, a photovoltaic module, and an electrical apparatus. The perovskite crystal comprises one or more perovskite grains; the perovskite crystal grain comprises a core part and a passivation layer located on at least part of the surface of the core part, the core part comprising a first perovskite component, and the passivation layer comprising a second perovskite component. The perovskite cell has high stability and high photoelectric conversion efficiency.

Description

Perovskite crystal, precursor solution, perovskite layer, perovskite cell, preparation method, photovoltaic module, electrical device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202310908816.3 filed on July 24, 2023, entitled “Perovskite crystals, precursor solutions, perovskite layers, perovskite cells, preparation methods, photovoltaic modules, and electrical devices,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to a perovskite crystal, a precursor solution, a perovskite layer, a perovskite cell, a preparation method, a photovoltaic module, and an electrical device. Background Art

[0004] With the development of modern industry, global energy shortage and environmental pollution problems are becoming increasingly prominent, and perovskite cells are receiving more and more attention as ideal renewable energy sources. Perovskite cells have potential advantages such as high efficiency and low cost, and are expected to show excellent competitiveness in the next generation of solar cells. Perovskite crystals and perovskite layers are one of the important components of perovskite cells, which will affect the performance of perovskite cells. However, the interior and surface of the perovskite layer prepared at present usually have a high defect state density, and defect-assisted non-radiative recombination and impurity scattering can affect the carrier dynamics process. Therefore, improving the bulk quality and interface quality of the perovskite layer and enhancing carrier transport are of great significance to improving the performance of battery devices. The above statements are only used to provide background technical information related to this application and do not necessarily constitute prior art.

[0005] Summary of the Invention

[0006] The present application provides a perovskite crystal, a precursor solution, a perovskite layer, a perovskite cell, a preparation method, a photovoltaic module, and an electrical device, which can enable the perovskite cell to have high stability and high photoelectric conversion efficiency.

[0007] In a first aspect, the present application provides a perovskite crystal, wherein the perovskite crystal includes one or more perovskite grains, wherein the perovskite grain includes a core and a passivation layer located on at least a portion of the surface of the core.

[0008] The core portion includes a first perovskite component, the passivation layer includes a second perovskite component, the first perovskite component includes one or more of ABX3, A2CDX6, and the second perovskite component includes one or more of APbX3, A in ABX3, A2CDX6 and APbX3 independently represents a monovalent inorganic cation, an organic cation or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation or an organic-inorganic mixed cation, X in ABX3, A2CDX6 and APbX3 independently represents a monovalent inorganic anion, an organic anion or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation or an organic-inorganic mixed cation.

[0009] The perovskite crystal provided in the embodiment of the present application includes one or more perovskite grains, the perovskite grains include a core and a passivation layer located on at least a portion of the surface of the core, the passivation layer includes a second perovskite component, and the second perovskite component includes a lead-based perovskite material APbX3, thereby not only making the perovskite crystal have high structural stability, but also making the perovskite crystal have a higher carrier transport ability, and also being beneficial to the energy level matching between the perovskite layer and the charge transport layer, thereby also being beneficial to improving the photoelectric conversion efficiency of the battery device.

[0010] In any embodiment, the passivation layer is integrally formed with the core portion, thereby further improving the stability and oxidation resistance of the perovskite crystal and promoting carrier transport, thereby facilitating high stability and high photoelectric conversion efficiency of a battery device using the perovskite crystal.

[0011] In any embodiment, the perovskite crystal further includes a third component, wherein the third component is located on the surface and / or grain boundary of the perovskite crystal, and the third component includes an alkyl group substituted with at least one of a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, a boric acid group, a cyano group, an amine group, a quaternary ammonium salt, and a thiol group, and the molecular size of the third component is greater than a first threshold value, and the first threshold value represents the maximum value of the ionic radius of the cations of the first perovskite component and the second perovskite component.

[0012] In any embodiment, the third component includes one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboronic acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0013] In any embodiment, the ratio of the thickness of the passivation layer to the grain size of the perovskite grains is greater than 0 and less than or equal to 0.33: 1. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0014] In any embodiment, the thickness of the passivation layer is 1 nm to 100 nm, thereby enabling the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0015] In any embodiment, the perovskite grains have a grain size of 300 nm to 1000 nm.

[0016] In any embodiment, the passivation layer is located on 80%-100% of the surface of the core portion, thereby helping the perovskite cell to have high stability.

[0017] In any embodiment, B includes Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ One or more of .

[0018] In any embodiment, A in ABX3, A2CDX6 and APbX3 independently comprises CH3NH3 + 、CH3CH2NH3 + 、CH(NH2)2 + 、Li + 、Na + , K + , Rb + 、Cs + One or more of .

[0019] In any embodiment, X in ABX3, A2CDX6 and APbX3 each independently represents a halogen ion.

[0020] In any embodiment, C represents a monovalent metal cation.

[0021] In any embodiment, D represents a trivalent metal cation.

[0022] A second aspect of the present application provides a precursor solution for preparing the perovskite crystal of the first aspect, wherein the precursor solution is obtained by mixing a first precursor solution and a second precursor solution.

[0023] The first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent.

[0024] The second precursor solution includes a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, wherein the third component includes at least one substituted alkyl group selected from the group consisting of sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt, and thiol group, and the molecular size of the third component is greater than a first threshold value, which represents the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution.

[0025] The second precursor solution includes a third component, and the molecular structure of the third component contains at least one functional group selected from sulfonic acid, phosphoric acid, carboxylic acid, boric acid, cyano, amine, quaternary ammonium salt, and thiol. Therefore, the third component in the second precursor solution can complex Pb 2+ . At the same time, the molecular size of the third component is larger than the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution. When preparing perovskite crystals by using the above-mentioned mixed precursor solution, due to the larger molecular size of the third component, it cannot be located in the cation position of the perovskite crystal, so these third components will exist as impurities. During the crystallization process, the third component will be squeezed to the grain boundary and surface of the perovskite crystal. And these third components contain 2+ Coordination or complexing groups, thus, during the grain growth process, the third component will drive Pb 2+ It detaches from the grain boundaries and surfaces of the perovskite crystals to form perovskite grains with a core-shell structure, and the passivation layer of the integrally formed perovskite grains can simultaneously passivate grain boundary defects and surface defects.

[0026] The first precursor solution and the second precursor solution are prepared separately, and the second precursor solution includes a third component, while the first precursor solution does not include the third component, so that the third component can complex the Pb in the second precursor solution. 2+ , and can reduce the third component to complex the optional metal cations in the first precursor solution, so that the core-shell structured perovskite grains can be formed integrally during the crystallization process.

[0027] In any embodiment, the third component includes one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboronic acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0028] In any embodiment, the molar ratio of the third component to PbX2 is 0.005:1-0.1:1. By adjusting the molar ratio of the third component to PbX2 within the above range, the crystallized perovskite grains can have a complete passivation layer, for example, the passivation layer is located on 80%-100% of the surface of the core, thereby improving the stability of the perovskite cell and also improving the photoelectric conversion efficiency of the perovskite cell.

[0029] In any embodiment, the first solvent includes dimethylformamide and dimethyl sulfoxide.

[0030] In any embodiment, the second solvent includes dimethylformamide and dimethyl sulfoxide.

[0031] A third aspect of the present application provides a perovskite layer, which includes the perovskite crystal of the first aspect of the present application.

[0032] In a fourth aspect, the present application provides a method for preparing a perovskite layer, comprising the following steps: providing a substrate; providing a precursor solution for forming a perovskite layer; coating the precursor solution for forming a perovskite layer on the substrate to form a thin film; and removing the solvent in the thin film to form a perovskite layer.

[0033] The precursor solution for forming the perovskite layer is obtained by mixing a first precursor solution and a second precursor solution, wherein the first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent, and the second precursor solution includes a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, wherein the third component includes at least one substituted alkyl group selected from sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt and thiol group, and the molecular size of the third component is greater than a first threshold value, and the first threshold value represents the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution.

[0034] The perovskite layer includes a perovskite crystal, which includes one or more perovskite grains. The perovskite grains include a core and a passivation layer located on at least a portion of the surface of the core. The core includes a first perovskite component, and the passivation layer includes a second perovskite component. The first perovskite component includes one or more of ABX3, A2CDX6, and APbX3. A in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, X in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic anion, an organic anion, or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation, or an organic-inorganic mixed cation.

[0035] The perovskite layer prepared by the method provided in the embodiments of the present application can enable the perovskite cell to have high stability and high photoelectric conversion efficiency.

[0036] In any embodiment, the third component includes one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboronic acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0037] In any embodiment, the molar ratio of the third component to PbX2 is 0.005:1-0.1:1. By adjusting the molar ratio of the third component to PbX2 within the above range, the crystallized perovskite grains can have a complete passivation layer, for example, the passivation layer is located on 80%-100% of the surface of the core, thereby improving the stability of the perovskite cell and also improving the photoelectric conversion efficiency of the perovskite cell.

[0038] In any embodiment, the first solvent includes dimethylformamide and dimethyl sulfoxide.

[0039] In any embodiment, the second solvent includes dimethylformamide and dimethyl sulfoxide.

[0040] In any embodiment, the step of removing the solvent in the thin film to form the perovskite layer includes the following steps: transferring the substrate with the thin film formed thereon to a hot stage for annealing to form the perovskite layer.

[0041] In a fifth aspect, the present application provides a perovskite cell, comprising: a first electrode, a second electrode, a perovskite layer, a first charge transport layer, and a second charge transport layer. The first electrode is located near the light-entering side, the perovskite layer is located between the first electrode and the second electrode, the first charge transport layer is located between the first electrode and the perovskite layer, and the second charge transport layer is located between the second electrode and the perovskite layer. The perovskite layer includes the perovskite layer of the third aspect of the present application, or a perovskite layer prepared by the method of the fourth aspect of the present application.

[0042] In a sixth aspect of the present application, a method for preparing a perovskite battery is provided, comprising the following steps: providing a first electrode; forming a first charge transport layer on the first electrode; providing a precursor solution for forming a perovskite layer; coating the precursor solution for forming the perovskite layer on the first charge transport layer to form a thin film; removing the solvent in the thin film to form a perovskite layer; forming a second charge transport layer on the perovskite layer; and forming a second electrode on the second charge transport layer.

[0043] The precursor solution for forming the perovskite layer is obtained by mixing a first precursor solution and a second precursor solution, wherein the first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent, and the second precursor solution includes a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, wherein the third component includes at least one substituted alkyl group selected from sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt and thiol group, and the molecular size of the third component is greater than a first threshold value, and the first threshold value represents the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution.

[0044] The perovskite layer includes a perovskite crystal, which includes one or more perovskite grains. The perovskite grains include a core and a passivation layer located on at least a portion of the surface of the core. The core includes a first perovskite component, and the passivation layer includes a second perovskite component. The first perovskite component includes one or more of ABX3, A2CDX6, and APbX3. A in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, X in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic anion, an organic anion, or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation, or an organic-inorganic mixed cation.

[0045] The perovskite cell prepared by the method provided in the embodiments of the present application can have high stability and high photoelectric conversion efficiency.

[0046] In any embodiment, the third component includes one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboronic acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0047] In any embodiment, the molar ratio of the third component to PbX2 is 0.005:1-0.1:1. By adjusting the molar ratio of the third component to PbX2 within the above range, the crystallized perovskite grains can have a complete passivation layer, for example, the passivation layer is located on 80%-100% of the surface of the core, thereby improving the stability of the perovskite cell and also improving the photoelectric conversion efficiency of the perovskite cell.

[0048] In any embodiment, the first solvent includes dimethylformamide and dimethyl sulfoxide.

[0049] In any embodiment, the second solvent includes dimethylformamide and dimethyl sulfoxide.

[0050] In any embodiment, the step of removing the solvent in the thin film to form the perovskite layer includes the following steps: transferring the first electrode formed with the thin film to a hot stage for annealing to form the perovskite layer.

[0051] The seventh aspect of the present application provides another perovskite layer, which includes a middle part and a passivation part located on at least a portion of the surface of the middle part; the middle part includes perovskite crystals; the passivation part includes a first passivation part located on the upper surface and / or lower surface of the middle part along the thickness direction and a second passivation part located on the outer peripheral surface of the middle part; the first passivation part and the second passivation part each independently include a passivation material, and the passivation material includes one or more of lead-based perovskite materials, lead sulfide, silicon carbide, oxides, polymers, and organic small molecules.

[0052] By applying a passivation material to the upper and / or lower surfaces of the middle portion along the thickness direction, as well as the outer periphery of the middle portion, the defect state density of the perovskite layer can be reduced, non-radiative recombination and impurity scattering can be minimized, and the stability of the battery device can be improved. Lead-based perovskite materials, lead sulfide, silicon carbide, oxides, polymers, and organic small molecules have passivation capabilities and can also transport carriers, thereby enabling the battery device to achieve high photoelectric conversion efficiency.

[0053] In any embodiment, the ratio of the thickness of the first passivation portion to the thickness of the middle portion is 1:5-1:20. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0054] In any embodiment, the ratio of the thickness of the second passivation portion to the thickness of the middle portion is 1:5-1:20. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0055] In any embodiment, the thickness of the middle portion is 400 nm-1000 nm.

[0056] In any embodiment, the oxide includes one or more of lead oxide, silicon oxide, aluminum oxide, and tin oxide, thereby not only improving the stability of the battery device, but also promoting carrier transport and improving the photoelectric conversion efficiency of the battery device.

[0057] In any embodiment, the polymer includes one or more of a homopolymer and a copolymer of at least one monomer selected from vinyl chloride, thiophene and its derivatives, carbazole and its derivatives, and styrenesulfonic acid. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0058] In any embodiment, the organic small molecule includes a compound containing at least one of a halogen atom and a heteroatom, and the heteroatom includes one or more of N, S, and O. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0059] In any embodiment, the perovskite crystal includes the perovskite crystal of the first aspect of the present application.

[0060] In an eighth aspect, the present application provides another perovskite cell, comprising: a first electrode, a second electrode, a perovskite layer, a first charge transport layer, and a second charge transport layer. The first electrode is located near the light-entering side, the perovskite layer is located between the first electrode and the second electrode, the first charge transport layer is located between the first electrode and the perovskite layer, and the second charge transport layer is located between the second electrode and the perovskite layer. The perovskite layer includes the perovskite layer according to the seventh aspect of the present application.

[0061] In any embodiment, the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, and the LUMO energy level of the first passivation portion is lower than the CBM energy level of the intermediate portion. This facilitates carrier transport and improves the photoelectric conversion efficiency of the battery device.

[0062] In any embodiment, the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, and the HOMO energy level of the first passivation portion is greater than the VBM energy level of the intermediate portion. This facilitates carrier transport and improves the photoelectric conversion efficiency of the battery device.

[0063] In any embodiment, the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, and the passivation portion includes a first passivation portion located on a surface of the middle portion away from the first charge transport layer and a second passivation portion located on a peripheral surface of the middle portion, and the LUMO energy level of the first passivation portion is lower than the CBM energy level of the middle portion. This facilitates carrier transport and improves the photoelectric conversion efficiency of the battery device.

[0064] In any embodiment, the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, the passivation portion includes a first passivation portion located on a surface of the middle portion away from the first charge transport layer, and a second passivation portion located on a peripheral surface of the middle portion, and the HOMO energy level of the first passivation portion is greater than the VBM energy level of the middle portion. This facilitates carrier transport and improves the photoelectric conversion efficiency of the battery device.

[0065] The ninth aspect of the present application provides a method for preparing the perovskite battery of the eighth aspect of the present application, comprising the following steps: providing a first electrode; forming a first charge transport layer on the first electrode; forming a perovskite layer on the first charge transport layer; forming a second charge transport layer on the perovskite layer; and forming a second electrode on the second charge transport layer.

[0066] In any embodiment, a method of forming the perovskite layer on the first charge transport layer includes a solution method, a hydrothermal method, and a vapor deposition method.

[0067] In any embodiment, the step of forming a perovskite layer on the first charge transport layer includes the following steps: providing a passivation material and a precursor solution for forming the intermediate portion; mixing the passivation material and the precursor solution for forming the intermediate portion, and applying the mixture to the first charge transport layer to form the perovskite layer, wherein the molar ratio of the passivation material to the precursor for forming the intermediate portion is 0.01:1-0.25:1. By adjusting the molar ratio of the passivation material to the precursor for forming the intermediate portion within the above range, a first passivation portion can be formed on the upper surface and / or lower surface of the intermediate portion along the thickness direction, and a second passivation portion can be simultaneously formed on the outer peripheral surface of the intermediate portion.

[0068] In any embodiment, the step of forming a perovskite layer on the first charge transport layer includes the following steps: providing a precursor solution for forming the middle portion, wherein the precursor solution for forming the middle portion is obtained by mixing a first precursor solution and a second precursor solution, wherein the first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent, and the second precursor solution includes a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, wherein the third component includes a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, a boric acid group, a cyano group, an amine group, At least one substituted alkyl selected from the group consisting of a quaternary ammonium salt and a thiol group, and the molecular size of the third component is greater than a first threshold value, the first threshold value representing the maximum ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution; the precursor solution for forming the intermediate portion is applied to the first charge transport layer to form a thin film; the solvent in the thin film is removed to form the intermediate portion; and a passivation material is applied to the upper surface and outer peripheral surface of the intermediate portion to complete the preparation of the perovskite layer. In this manner, the perovskite crystals formed in the intermediate portion include the perovskite crystals of the first aspect of the present application.

[0069] In any embodiment, before coating the precursor solution for forming the intermediate portion on the first charge transport layer to form a thin film, the method further includes applying a passivation material on the first charge transport layer.

[0070] The tenth aspect of the present application provides a photovoltaic module, which includes the perovskite cell of the fifth aspect of the present application, or the perovskite cell prepared by the method of the sixth aspect of the present application, or the perovskite cell of the eighth aspect of the present application, or the perovskite cell prepared by the method of the ninth aspect of the present application.

[0071] The eleventh aspect of the present application provides an electrical device, which includes one or more of the perovskite cell of the fifth aspect of the present application, the perovskite cell prepared by the method of the sixth aspect of the present application, the perovskite cell of the eighth aspect of the present application, the perovskite cell prepared by the method of the ninth aspect of the present application, and the photovoltaic component of the tenth aspect of the present application, and the perovskite cell and the photovoltaic component are used to supply power to the electrical device.

[0072] The electrical device of the present application includes the perovskite battery provided by the present application, and thus has at least the same advantages as the perovskite battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on the drawings without inventive effort.

[0074] FIG1 is a schematic diagram of the structure of perovskite grains provided in some embodiments of the present application.

[0075] FIG2 is a schematic structural diagram of a perovskite battery provided in some embodiments of the present application.

[0076] FIG3 is a schematic structural diagram of a perovskite battery provided in some other embodiments of the present application.

[0077] FIG4 is a schematic structural diagram of a perovskite battery provided in some other embodiments of the present application.

[0078] In the accompanying drawings, which are not necessarily drawn to scale, the reference numerals are as follows: 1, first electrode; 2, first charge transport layer; 3, perovskite layer; 4, second charge transport layer; 5, second electrode; 31, perovskite grain; 311, core portion; 312, passivation layer; 32, intermediate portion; 33, passivation portion; 331, first passivation portion; 332, second passivation portion. DETAILED DESCRIPTION

[0079] Below, the embodiments of the perovskite crystal, precursor solution, perovskite layer, perovskite cell, preparation method, photovoltaic module, and electrical device of the present application are described in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0080] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0081] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0082] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of this application.

[0083] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0084] Unless otherwise specified, in this application, the terms "first", "second", etc. are used to distinguish different objects rather than to describe a specific order or a primary-secondary relationship.

[0085] Unless otherwise specified, the terms used in this application have the common meanings that are commonly understood by those skilled in the art.

[0086] Unless otherwise specified, the values ​​of the parameters mentioned in this application can be measured using various test methods commonly used in the art, for example, they can be measured according to the test methods provided in this application. Unless otherwise specified, the test temperature for each parameter is 25°C.

[0087] The term "small organic molecule" is used in the ordinary sense of the art. Typically, small organic molecules contain carbon atoms. It will be understood by those skilled in the art that the term "small organic molecule" does not generally include compounds that are primarily in ionic form, such as carbides.

[0088] [Perovskite crystal]

[0089] In a first aspect, embodiments of the present application provide a perovskite crystal that can be used in a perovskite battery.

[0090] FIG1 is a schematic diagram of the structure of perovskite grains provided in some embodiments of the present application.

[0091] As shown in FIG. 1 , the perovskite crystal includes one or more perovskite grains 31 . The perovskite grain 31 includes a core 311 and a passivation layer 312 located on at least a portion of the surface of the core 311 .

[0092] The core portion 311 includes a first perovskite component, and the passivation layer 312 includes a second perovskite component.

[0093] The first perovskite component includes one or more of ABX3, A2CDX6, and the second perovskite component includes one or more of APbX3.

[0094] A in ABX3, A2CDX6 and APbX3 each independently represents a monovalent inorganic cation, an organic cation or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation or an organic-inorganic mixed cation, X in ABX3, A2CDX6 and APbX3 each independently represents a monovalent inorganic anion, an organic anion or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation or an organic-inorganic mixed cation.

[0095] The perovskite crystal includes one or more perovskite grains, and thus the perovskite crystal can be either a single crystal or a polycrystalline.

[0096] The operating principle of a perovskite cell is generally as follows: under illumination, the perovskite layer absorbs photon energy, generating electron-hole pairs in its valence band. Electrons are excited to the conduction band, leaving holes in the valence band. The conduction band energy level of the perovskite layer is typically higher than that of the electron transport layer, allowing electrons to transfer from the perovskite layer to the electron transport layer, and then to the conductive electrode. The valence band energy level of the perovskite layer is typically lower than that of the hole transport layer, allowing holes to transfer from the hole transport layer to the conductive electrode. When connected to an external circuit, this completes the circuit, generating a photocurrent.

[0097] Perovskite crystals, such as tin-lead mixed perovskite crystals, have problems such as easy oxidation, non-uniformity and rapid nucleation and crystallization, which result in a high defect state density inside and on the surface of the perovskite layer. Defect-assisted non-radiative recombination and impurity scattering can affect the carrier dynamics process.

[0098] Providing a passivation layer with a passivating effect on the surface of the perovskite grains can improve the stability of the perovskite crystals, reduce the defect state density of the perovskite layer, and improve the oxidation resistance of the perovskite layer, thereby improving the stability of the battery device. However, the current passivation layer is usually formed by directly coating or depositing on the surface of the prepared perovskite crystal, which will form an interface between the perovskite crystal and the passivation layer on its surface. The existence of the interface will affect the stability of the perovskite crystal and also affect the carrier transport; at the same time, the defects at the grain boundaries of the perovskite grains cannot be passivated, thereby affecting the stability of the perovskite crystal. In addition, the current passivation layer on the surface of the perovskite crystal usually uses some inactive molecules, which will affect the transport of carriers and thus affect the photoelectric conversion efficiency of the battery device.

[0099] The perovskite crystal provided in the embodiment of the present application includes one or more perovskite grains, the perovskite grains include a core and a passivation layer located on at least a portion of the surface of the core, the passivation layer includes a second perovskite component, and the second perovskite component includes a lead-based perovskite material APbX3, thereby not only making the perovskite crystal have high structural stability, but also making the perovskite crystal have a higher carrier transport ability, and also being beneficial to the energy level matching between the perovskite layer and the charge transport layer, thereby also being beneficial to improving the photoelectric conversion efficiency of the battery device.

[0100] The passivation layer 312 is integrally formed with the core portion 311. The passivation layer and the core portion are integrally formed in that there is no interface between the passivation layer and the core portion, and the material of the passivation layer and the material of the core portion are different.

[0101] The core of the perovskite grain provided in the embodiment of the present application is formed integrally with the passivation layer, thereby further improving the stability and oxidation resistance of the perovskite crystal, and promoting carrier transport, thereby facilitating high stability and high photoelectric conversion efficiency of the battery device using the perovskite grain.

[0102] Therefore, the perovskite cell using the perovskite crystal provided in the embodiments of the present application can have high stability and high photoelectric conversion efficiency.

[0103] In some embodiments, B in ABX3 may include Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ One or more of .

[0104] In some embodiments, B in ABX3 may include Pb 2+ 、Sn 2+ One or both of them.

[0105] In some embodiments, B in ABX3 may include Sn 2+ , or, B in ABX3 also includes Pb 2+ and Sn 2+ .

[0106] Lead-tin perovskite cells are a new type of high-efficiency solar cell technology. Compared with other perovskite crystals, lead-tin mixed perovskite crystals have narrower band gaps and lower toxicity, making them ideal bottom cell materials for tandem cells. However, lead-tin perovskite cells have a serious oxidation problem, which is mainly due to the presence of Sn on the surface of the perovskite crystal and the passivation layer. 2+ . Sn 2+ It has strong reducing properties in redox reactions and is easily oxidized to Sn 4+ , and Sn 4+ The electronic structure of the lead-tin perovskite battery is unstable and easily forms electron-hole pairs, which increases the difficulty of carrier transmission inside the lead-tin perovskite battery and reduces the photoelectric conversion efficiency and stability of the lead-tin perovskite battery.

[0107] The perovskite crystal provided in the embodiment of the present application includes one or more perovskite grains, the perovskite grains including a core and a passivation layer located on at least a portion of the surface of the core, the passivation layer including a second perovskite component, and the second perovskite component including a lead-based perovskite material, thereby the surfaces of the perovskite grains, the perovskite crystals, and the perovskite layer are all stable Pb 2+ , which can reduce or even avoid Sn in the perovskite layer 2+ Oxidized to Sn 4+ , which can improve the stability of the battery device and also enable the battery device to have high photoelectric conversion efficiency.

[0108] In some embodiments, B in ABX3 may include Pb 2+ , and A in APbX3 may represent a monovalent inorganic cation. Alternatively, A in APbX3 may include Li + 、Na + , K + , Rb + 、Cs + More optionally, A in APbX3 may include Cs + .

[0109] When the first perovskite component also includes a lead-based perovskite material, by using a more stable monovalent inorganic cation at the A position in the second perovskite component in the passivation layer, it helps to improve the structural stability of the perovskite crystal and the stability of the battery device.

[0110] In some embodiments, A in ABX3, A2CDX6, and APbX3 may each independently comprise CH3NH3 + (abbreviated as MA + ), CH3CH2NH3 + 、CH(NH2)2 + (abbreviated as FA + )、Li + 、Na + , K + , Rb + 、Cs + Optionally, A in ABX3, A2CDX6 and APbX3 can each independently include CH3NH3 + 、CH3CH2NH3 + 、CH(NH2)2 + 、Cs + One or more of .

[0111] The A in ABX3, A2CDX6 and APbX3 can be the same or different, and this embodiment of the present application does not limit this.

[0112] In some embodiments, X in ABX3, A2CDX6 and APbX3 can each independently represent a halogen ion. Alternatively, X in ABX3, A2CDX6 and APbX3 can each independently include F - 、Cl - Br - , I - More preferably, X in ABX3, A2CDX6 and APbX3 can each independently include Cl - Br - , I - One or more of .

[0113] X in ABX3, A2CDX6 and APbX3 can be the same or different, and this is not limited in the embodiments of the present application.

[0114] In some embodiments, C in A2CDX6 may represent a monovalent metal cation. Alternatively, C in A2CDX6 may include Li + 、Na + , K + , Rb + 、Cs + 、Ag + One or more of .

[0115] In some embodiments, D in A2CDX6 may represent a trivalent metal cation. Alternatively, D in A2CDX6 may include In 3+ 、Bi 3+ 、Sb 3+ One or more of .

[0116] In some embodiments, the perovskite crystal further includes a third component, which is located on the surface and / or grain boundary of the perovskite crystal, and the third component includes an alkyl group substituted with at least one of sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt, and thiol group, and the molecular size of the third component is greater than a first threshold value, and the first threshold value represents the maximum value of the ionic radius of the cations of the first perovskite component and the second perovskite component.

[0117] Alternatively, the third component may include, but is not limited to, one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboronic acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0118] In some embodiments, a ratio of the thickness of the passivation layer of the perovskite grains to the grain size of the perovskite grains may be greater than 0 and less than or equal to 0.33:1.

[0119] Optionally, the ratio of the thickness of the passivation layer of the perovskite grains to the grain size of the perovskite grains can be 0.002:1-0.23:1, 0.005:1-0.20:1, 0.01:1-0.17:1, or 0.02:1-0.14:1. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0120] In some embodiments, the thickness of the passivation layer of the perovskite grains may be 1 nm to 100 nm. For example, the thickness of the passivation layer may be 1 nm, 3 nm, 5 nm, 10 nm, 15 nm, 20 nm, 28 nm, 44 nm, 56 nm, 65 nm, 71 nm, 80 nm, 94 nm, 100 nm, or a range consisting of any of the above values. Alternatively, the thickness of the passivation layer of the perovskite grains may be 10 nm to 94 nm, 12 nm to 71 nm, or 15 nm to 56 nm. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0121] The grain size of the perovskite grains is not specifically limited. In some embodiments, the grain size of the perovskite grains can be 300 nm-1000 nm. For example, the grain size of the perovskite crystals can be 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, or a range consisting of any of the above values.

[0122] The thickness of the passivation layer of a perovskite grain can be measured using a scanning electron microscope or a transmission electron microscope. During the test, 10 areas can be randomly selected from the perovskite layer. For each area, 3-5 cross-sectional images of the perovskite layer can be obtained using a scanning electron microscope or a transmission electron microscope. The maximum thickness of the passivation layer in each cross-sectional image is recorded, and the average value is taken as the thickness of the passivation layer of the perovskite grain.

[0123] The grain size of the perovskite grains can be tested using a scanning electron microscope or a transmission electron microscope. During the test, a top view of the perovskite layer can be obtained using a scanning electron microscope or a transmission electron microscope. Three areas are randomly selected from the top view of the perovskite layer (ensuring that the number of perovskite grains in each area is greater than or equal to 80). The grain size of all perovskite grains in the three areas is obtained, and then the average value is taken as the grain size of the perovskite grains. In the top view of the perovskite layer, the maximum length of each perovskite grain is used as the grain size of each perovskite grain.

[0124] In some embodiments, the passivation layer may be located on 80% to 100% of the surface of the core, thereby contributing to high stability of the perovskite cell.

[0125] In some embodiments, the first perovskite component may include but is not limited to CH3NH3PbI3 (abbreviated as MAPbI3), CH(NH2)2PbI3 (abbreviated as FAPbI3), Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 )3. CsPbI3, CsPbI2Br, CsPbIBr2, FAPb 0.5 Sn 0.5 I3、MAPb 0.5 Sn 0.5 I3, FASnI3, MASnI3, CsSnI3, Cs 0.2 FA 0.8 Pb 0.5 Sn 0.5 I3, MA 0.2 FA 0.8 Pb 0.5 Sn 0.5 I3, MA 0.5 FA 0.5 Pb 0.5 Sn 0.5 I3、Cs 0.2 MA 0.8 Pb 0.5 Sn 0.5 One or more of I3, Cs2NaInCl6, Cs2KBiCl6, and Cs2AgInCl6.

[0126] In some embodiments, the second perovskite component may include but is not limited to CH3NH3PbI3 (abbreviated as MAPbI3), CH(NH2)2PbI3 (abbreviated as FAPbI3), Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 )3, one or more of CsPbCl3, MAPbCl3, FAPbCl3, FAPbBr3, MAPbBr3, CsPbBr3, CsPbBr3, CsPbI3, CsPbI2Br, and CsPbIBr2.

[0127] [Precursor solution]

[0128] In a second aspect, the embodiments of the present application further provide a precursor solution for preparing the perovskite crystals provided in the first aspect of the embodiments of the present application.

[0129] The precursor solution is obtained by mixing a first precursor solution and a second precursor solution.

[0130] The first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent.

[0131] The second precursor solution includes a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, wherein the third component includes an alkyl group substituted with at least one of sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt, and thiol group, and the molecular size of the third component is greater than a first threshold value, which represents the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution.

[0132] The second precursor solution includes a third component, and the molecular structure of the third component contains at least one functional group selected from sulfonic acid, phosphoric acid, carboxylic acid, boric acid, cyano, amine, quaternary ammonium salt, and thiol. Therefore, the third component in the second precursor solution can complex Pb 2+ . At the same time, the molecular size of the third component is larger than the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution. When preparing perovskite crystals by using the above-mentioned mixed precursor solution, due to the larger molecular size of the third component, it cannot be located in the cation position of the perovskite crystal, so these third components will exist as impurities. During the crystallization process, the third component will be squeezed to the grain boundary and surface of the perovskite crystal. And these third components contain 2+ Coordination or complexing groups, thus, during the grain growth process, the third component will drive Pb 2+ It detaches from the grain boundaries and surfaces of the perovskite crystals to form perovskite grains with a core-shell structure, and the passivation layer of the integrally formed perovskite grains can simultaneously passivate grain boundary defects and surface defects.

[0133] The first precursor solution and the second precursor solution are prepared separately, and the second precursor solution includes a third component, while the first precursor solution does not include the third component, so that the third component can complex the Pb in the second precursor solution. 2+ , and can reduce the third component to complex the optional metal cations in the first precursor solution, so that the core-shell structured perovskite grains can be formed integrally during the crystallization process.

[0134] In the above preparation method, the second precursor solution can form the second perovskite component in the passivation layer.

[0135] In the above preparation method, the first precursor solution can form the first perovskite component in the core. Alternatively, the first precursor solution and the second precursor solution can jointly form the first perovskite component in the core. Thus, during the crystallization process, a portion of the second precursor solution forms the second perovskite component in the passivation layer, while another portion co-crystallizes with the first precursor solution to form the first perovskite component in the core.

[0136] A in the first precursor solution and A in the second precursor solution can be the same or different; X in the first precursor solution and X in the second precursor solution can be the same or different; X in the A-site precursor compound AX in the first precursor solution and X in the B-site precursor compound BX2 can be the same or different; X in the A-site precursor compound AX in the second precursor solution and X in PbX2 can be the same or different. Those skilled in the art can make adjustments based on actual conditions to prepare the above-mentioned perovskite crystals.

[0137] In some embodiments, the third component may include, but is not limited to, one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboronic acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0138] In some embodiments, the molar ratio of the third component to PbX2 can be 0.005:1-0.1:1, optionally 0.01:1-0.05:1.

[0139] By adjusting the molar ratio of the third component to PbX2 within the above range, the crystallized perovskite grains can have a complete passivation layer, for example, the passivation layer is located on 80%-100% of the surface of the core, which is beneficial to improving the stability of the perovskite battery and also beneficial to improving the photoelectric conversion efficiency of the perovskite battery. When the molar ratio of the third component to PbX2 is small, the passivation layer of the crystallized perovskite grains may not be complete, which is not conducive to modifying the grain boundary defects and surface defects of the perovskite crystals, thereby reducing the stability of the prepared battery device. When the molar ratio of the third component to PbX2 is large, the excess third component may complex with the metal cations in the first perovskite component, which is not conducive to the formation of core-shell structured perovskite grains, and is not conducive to improving the stability of the battery device. In addition, excessive third components will also accumulate (or stack) on the surface and grain boundary positions of the perovskite crystals, thereby increasing the interface resistance of the perovskite layer, affecting the transport of carriers, and further affecting the photoelectric conversion efficiency of the battery device.

[0140] In some embodiments, the first solvent may include, but is not limited to, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Optionally, the volume ratio of dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) may be 2:1-9:1.

[0141] In some embodiments, the second solvent may include, but is not limited to, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Optionally, the volume ratio of dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) may be 2:1-9:1.

[0142] [Perovskite layer]

[0143] In a third aspect, the embodiments of the present application further provide a perovskite layer, which includes the perovskite crystal provided in the first aspect of the embodiments of the present application.

[0144] [Method for preparing perovskite layer]

[0145] In a fourth aspect, the embodiments of the present application also provide a method for preparing the perovskite layer provided in the third aspect of the embodiments of the present application.

[0146] The method comprises the following steps: providing a substrate; providing a precursor solution for forming a perovskite layer; coating the precursor solution for forming the perovskite layer on the substrate to form a thin film; and removing the solvent in the thin film to form the perovskite layer.

[0147] A precursor solution for forming a perovskite layer is obtained by mixing a first precursor solution and a second precursor solution. The first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes the first solvent and an A-site precursor compound AX, a C-site precursor compound CX, and a D-site precursor compound DX3 dissolved in the first solvent. The second precursor solution includes a second solvent and the A-site precursor compound AX, PbX2, and a third component dissolved in the second solvent. The third component includes an alkyl group substituted with at least one of sulfonic acid, phosphate, carboxylic acid, boric acid, cyano, amine, quaternary ammonium salt, and thiol, and the molecular size of the third component is greater than a first threshold value, which represents the maximum ionic radius of the cations of the precursor compounds in the first and second precursor solutions.

[0148] The perovskite layer includes a perovskite crystal, each of which includes one or more perovskite grains. The perovskite grains include a core and a passivation layer located on at least a portion of the surface of the core. The core includes a first perovskite component, and the passivation layer includes a second perovskite component. The first perovskite component includes one or more of ABX3, A2CDX6, and the second perovskite component includes one or more of APbX3. A in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, X in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic anion, an organic anion, or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation, or an organic-inorganic mixed cation.

[0149] In some embodiments, the perovskite crystal further includes a third component located on the surface and / or grain boundaries of the perovskite crystal.

[0150] The third component in the second precursor solution can complex Pb 2+ , and the molecular size of the third component is larger than the maximum ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution. When the perovskite layer is formed by using the above-mentioned mixed precursor solution, due to the larger molecular size of the third component, it cannot be located in the cation position of the perovskite crystal, so these third components will exist as impurities. During the crystallization process, the third component will be squeezed to the grain boundary and surface of the perovskite crystal. And these third components contain 2+ Coordination or complexing groups, thus, during the grain growth process, the third component will drive Pb 2+ It detaches from the grain boundaries and surfaces of the perovskite crystals to form perovskite grains with a core-shell structure, and the passivation layer of the integrally formed perovskite grains can simultaneously passivate grain boundary defects and surface defects.

[0151] The first precursor solution and the second precursor solution are prepared separately, and the second precursor solution includes a third component, while the first precursor solution does not include the third component, so that the third component can complex the Pb in the second precursor solution. 2+ , and can reduce the third component to complex the optional metal cations in the first precursor solution, so that the core-shell structured perovskite grains can be formed integrally during the crystallization process.

[0152] Therefore, the perovskite layer prepared by the method provided in the embodiments of the present application can make the perovskite cell have high stability and high photoelectric conversion efficiency.

[0153] In the above preparation method, the second precursor solution can form the second perovskite component in the passivation layer.

[0154] In the above preparation method, the first precursor solution can form the first perovskite component in the core. Alternatively, the first precursor solution and the second precursor solution can jointly form the first perovskite component in the core. Thus, during the crystallization process, a portion of the second precursor solution forms the second perovskite component in the passivation layer, while another portion co-crystallizes with the first precursor solution to form the first perovskite component in the core.

[0155] A in the first precursor solution and A in the second precursor solution may be the same or different; X in the first precursor solution and X in the second precursor solution may be the same or different; X in the A-site precursor compound AX in the first precursor solution and X in the B-site precursor compound BX2 may be the same or different; X in the A-site precursor compound AX in the second precursor solution and X in PbX2 may be the same or different. Those skilled in the art may adjust according to actual conditions.

[0156] In some embodiments, the third component may include, but is not limited to, one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboronic acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0157] In some embodiments, the molar ratio of the third component to PbX2 can be 0.005:1-0.1:1, optionally 0.01:1-0.05:1.

[0158] By adjusting the molar ratio of the third component to PbX2 within the above range, the crystallized perovskite grains can have a complete passivation layer, for example, the passivation layer is located on 80%-100% of the surface of the core, which is beneficial to improving the stability of the perovskite battery and also beneficial to improving the photoelectric conversion efficiency of the perovskite battery. When the molar ratio of the third component to PbX2 is small, the passivation layer of the crystallized perovskite grains may not be complete, which is not conducive to modifying the grain boundary defects and surface defects of the perovskite crystals, thereby reducing the stability of the prepared battery device. When the molar ratio of the third component to PbX2 is large, the excess third component may complex with the metal cations in the first perovskite component, which is not conducive to the formation of core-shell structured perovskite grains, and is not conducive to improving the stability of the battery device. In addition, excessive third components will also accumulate (or stack) on the surface and grain boundary positions of the perovskite crystals, thereby increasing the interface resistance of the perovskite layer, affecting the transport of carriers, and further affecting the photoelectric conversion efficiency of the battery device.

[0159] In some embodiments, the first solvent may include, but is not limited to, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Optionally, the volume ratio of dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) may be 2:1-9:1.

[0160] In some embodiments, the second solvent may include, but is not limited to, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Optionally, the volume ratio of dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) may be 2:1-9:1.

[0161] In some embodiments, the step of removing the solvent in the thin film to form the perovskite layer includes the following steps: transferring the substrate with the thin film formed thereon to a hot stage for annealing to form the perovskite layer.

[0162] In some embodiments, the annealing temperature may be 80° C.-210° C. When the annealing temperature is within the above range, the second perovskite component may form a complete passivation layer, and the decomposition problem of the passivation layer may be reduced.

[0163] In some embodiments, the annealing time may be 1 min to 30 min. When the annealing time is within the above range, the second perovskite component can form a complete passivation layer and the decomposition problem of the passivation layer can be reduced.

[0164] [Perovskite battery]

[0165] In a fifth aspect, an embodiment of the present application also provides a perovskite battery.

[0166] FIG2 is a schematic structural diagram of a perovskite battery provided in some embodiments of the present application.

[0167] As shown in Figure 2, the perovskite cell includes a first electrode 1, a second electrode 5, a perovskite layer 3, a first charge transport layer 2, and a second charge transport layer 4. The first electrode 1 is close to the light incident side, the perovskite layer 3 is located between the first electrode 1 and the second electrode 5, the first charge transport layer 2 is located between the first electrode 1 and the perovskite layer 3, and the second charge transport layer 4 is located between the second electrode 5 and the perovskite layer 3.

[0168] The perovskite layer 3 includes the perovskite layer provided in the third aspect of the embodiment of the present application, or the perovskite layer prepared by the method provided in the fourth aspect of the embodiment of the present application. Therefore, the perovskite cell provided in the embodiment of the present application can have high stability and high photoelectric conversion efficiency.

[0169] The thickness of the perovskite layer 3 is not particularly limited and can be selected according to actual needs. In some embodiments, the thickness of the perovskite layer 3 can be 400 nm-1000 nm.

[0170] The perovskite cell provided in the embodiments of the present application may be a regular structure cell or a reverse structure cell.

[0171] In some embodiments, the first charge transport layer 2 is a hole transport layer, and the second charge transport layer 4 is an electron transport layer, thereby forming an inverted structure battery.

[0172] In some embodiments, the first charge transport layer 2 is an electron transport layer, and the second charge transport layer 4 is a hole transport layer, thereby forming a formal structure battery.

[0173] The type of electron transport material in the electron transport layer is not particularly limited and can be selected according to actual needs. For example, the electron transport material can include one or more of an organic electron transport material, an inorganic electron transport material, and an organic-inorganic hybrid electron transport material.

[0174] In some embodiments, the electron transport material may include but is not limited to one or more of the following materials and their derivatives and materials obtained by doping or passivation: [6,6]-phenyl C 61 Methyl butyrate (abbreviated as PC 61 BM), [6,6]-phenyl C 71 Methyl butyrate (abbreviated as PC 71 BM), fullerene C60, fullerene C70, SnO2, TiO2, ZnO. When the electron transport material is within the above range, its conduction band bottom energy level can better match the conduction band bottom energy level of the perovskite layer, thereby facilitating electron transport.

[0175] The thickness of the electron transport layer is not particularly limited and can be selected according to actual needs. For example, in some embodiments, the thickness of the electron transport layer can be 1 nm-300 nm.

[0176] The type of hole transport material in the hole transport layer is not particularly limited and can be selected according to actual needs. For example, the hole transport material can include one or more of organic small molecule hole transport materials, organic polymer hole transport materials, and inorganic hole transport materials.

[0177] In some embodiments, the hole transport material may include, but is not limited to, one or more of the following materials and their derivatives and materials obtained by doping or passivation: poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (abbreviated as PTAA), poly3-hexylthiophene (abbreviated as P3HT), triphenylamine with triptycene as the core (abbreviated as H101), 3,4-ethylenedioxythiophene-methoxytriphenylamine (abbreviated as EDOT-OMeTPA), N-(4-phenylamino)carbazole-spirobifluorene (abbreviated as CzPAF-SBF), poly(3,4-ethylenedioxythiophene):polystyrenesulfonic acid (abbreviated as PEDOT:PSS), 2,2',7,7'-tetrakis(N,N-p-methoxyanilino)-9,9'-spirobifluorene (abbreviated as Spiro-OMeTAD), methoxytriphenylamine-fluoroformamidine (abbreviated as OMeTPA-FA), polythiophene, nickel oxide (NiO x , 0<x<1), molybdenum oxide (MoO3), cuprous iodide (CuI), cuprous oxide (Cu2O), cuprous thiocyanate (CuSCN).

[0178] The thickness of the hole transport layer is not particularly limited and can be selected according to actual needs. For example, in some embodiments, the thickness of the hole transport layer can be 5 nm-1000 nm.

[0179] In some embodiments, the electrode material of the first electrode 1 may include an organic conductive material, an inorganic conductive material, or an organic-inorganic hybrid conductive material. As an example, the electrode material of the first electrode 1 may include, but is not limited to, one or more of a first transparent conductive metal oxide, carbon, and a metal, and may optionally include one or more of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), indium-doped zinc oxide (IZO), gold, silver, aluminum, copper, and carbon, and more optionally include one or more of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), and indium-doped zinc oxide (IZO).

[0180] The thickness of the first electrode is not particularly limited and can be selected according to actual needs. For example, in some embodiments, the thickness of the first electrode 1 can be 10 nm-700 nm.

[0181] In some embodiments, the electrode material of the second electrode 5 may include an organic conductive material, an inorganic conductive material, or an organic-inorganic hybrid conductive material. As an example, the electrode material of the second electrode 5 may include, but is not limited to, one or more of a first transparent conductive metal oxide, carbon, and a metal, and may optionally include one or more of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), indium-doped zinc oxide (IZO), gold, silver, aluminum, copper, and carbon, and more optionally include one or more of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), and indium-doped zinc oxide (IZO).

[0182] The thickness of the second electrode 5 is not particularly limited and can be selected according to actual needs. For example, in some embodiments, the thickness of the second electrode 5 can be 10 nm-700 nm.

[0183] In some embodiments, the perovskite cell further includes a substrate, such as a glass substrate, and a transparent metal conductive oxide may be disposed on the surface of the substrate.

[0184] The perovskite cell provided in the embodiments of the present application is not limited to the above structure, and may also include other functional layers.

[0185] [Method for preparing perovskite battery]

[0186] In a sixth aspect, the embodiments of the present application also provide a method for preparing the perovskite battery provided in the fifth aspect of the embodiments of the present application.

[0187] The method includes the following steps: providing a first electrode; forming a first charge transport layer on the first electrode; providing a precursor solution for forming a perovskite layer; coating the precursor solution for forming the perovskite layer on the first charge transport layer to form a thin film; removing the solvent in the thin film to form a perovskite layer; forming a second charge transport layer on the perovskite layer; and forming a second electrode on the second charge transport layer.

[0188] A precursor solution for forming a perovskite layer is obtained by mixing a first precursor solution and a second precursor solution. The first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes the first solvent and an A-site precursor compound AX, a C-site precursor compound CX, and a D-site precursor compound DX3 dissolved in the first solvent. The second precursor solution includes a second solvent and the A-site precursor compound AX, PbX2, and a third component dissolved in the second solvent. The third component includes an alkyl group substituted with at least one of sulfonic acid, phosphate, carboxylic acid, boric acid, cyano, amine, quaternary ammonium salt, and thiol, and the molecular size of the third component is greater than a first threshold value, which represents the maximum ionic radius of the cations of the precursor compounds in the first and second precursor solutions.

[0189] The perovskite layer of the perovskite cell includes a perovskite crystal, each of which includes one or more perovskite grains. The perovskite grains include a core and a passivation layer located on at least a portion of the surface of the core. The core includes a first perovskite component, and the passivation layer includes a second perovskite component. The first perovskite component includes one or more of ABX3, A2CDX6, and the second perovskite component includes one or more of APbX3. A in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, X in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic anion, an organic anion, or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation, or an organic-inorganic mixed cation.

[0190] In some embodiments, the perovskite crystal further includes a third component located on the surface and / or grain boundaries of the perovskite crystal.

[0191] The third component in the second precursor solution can complex Pb 2+ , and the molecular size of the third component is larger than the maximum ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution. When the perovskite layer is formed by using the above-mentioned mixed precursor solution, due to the larger molecular size of the third component, it cannot be located in the cation position of the perovskite crystal, so these third components will exist as impurities. During the crystallization process, the third component will be squeezed to the grain boundary and surface of the perovskite crystal. And these third components contain 2+ Coordination or complexing groups, thus, during the grain growth process, the third component will drive Pb 2+It detaches from the grain boundaries and surfaces of the perovskite crystals to form perovskite grains with a core-shell structure, and the passivation layer of the integrally formed perovskite grains can simultaneously passivate grain boundary defects and surface defects.

[0192] The first precursor solution and the second precursor solution are prepared separately, and the second precursor solution includes a third component, while the first precursor solution does not include the third component, so that the third component can complex the Pb in the second precursor solution. 2+ , and can reduce the third component to complex the optional metal cations in the first precursor solution, so that the core-shell structured perovskite grains can be formed integrally during the crystallization process.

[0193] Therefore, the perovskite cell prepared by the method provided in the embodiments of the present application can have high stability and high photoelectric conversion efficiency.

[0194] In the above preparation method, the second precursor solution can form the second perovskite component in the passivation layer.

[0195] In the above preparation method, the first precursor solution can form the first perovskite component in the core. Alternatively, the first precursor solution and the second precursor solution can jointly form the first perovskite component in the core. Thus, during the crystallization process, a portion of the second precursor solution forms the second perovskite component in the passivation layer, while another portion co-crystallizes with the first precursor solution to form the first perovskite component in the core.

[0196] A in the first precursor solution and A in the second precursor solution may be the same or different; X in the first precursor solution and X in the second precursor solution may be the same or different; X in the A-site precursor compound AX in the first precursor solution and X in the B-site precursor compound BX2 may be the same or different; X in the A-site precursor compound AX in the second precursor solution and X in PbX2 may be the same or different. Those skilled in the art may adjust according to actual conditions.

[0197] In some embodiments, the third component may include, but is not limited to, one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboronic acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0198] In some embodiments, the molar ratio of the third component to PbX2 can be 0.005:1-0.1:1, optionally 0.01:1-0.05:1.

[0199] By adjusting the molar ratio of the third component to PbX2 within the above range, the crystallized perovskite grains can have a complete passivation layer, for example, the passivation layer is located on 80%-100% of the surface of the core, which is beneficial to improving the stability of the perovskite battery and also beneficial to improving the photoelectric conversion efficiency of the perovskite battery. When the molar ratio of the third component to PbX2 is small, the passivation layer of the crystallized perovskite grains may not be complete, which is not conducive to modifying the grain boundary defects and surface defects of the perovskite crystals, thereby reducing the stability of the prepared battery device. When the molar ratio of the third component to PbX2 is large, the excess third component may complex with the metal cations in the first perovskite component, which is not conducive to the formation of core-shell structured perovskite grains, and is not conducive to improving the stability of the battery device. In addition, excessive third components will also accumulate (or stack) on the surface and grain boundary positions of the perovskite crystals, thereby increasing the interface resistance of the perovskite layer, affecting the transport of carriers, and further affecting the photoelectric conversion efficiency of the battery device.

[0200] In some embodiments, the first solvent may include, but is not limited to, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Optionally, the volume ratio of dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) may be 2:1-9:1.

[0201] In some embodiments, the second solvent may include, but is not limited to, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Optionally, the volume ratio of dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) may be 2:1-9:1.

[0202] In some embodiments, the step of removing the solvent in the thin film to form the perovskite layer includes the following steps: transferring the first electrode formed with the thin film to a hot stage for annealing to form the perovskite layer.

[0203] In some embodiments, the annealing temperature is 80° C.-210° C. When the annealing temperature is within the above range, the second perovskite component can form a complete passivation layer and the decomposition problem of the passivation layer can be reduced.

[0204] In some embodiments, the annealing time is 1 min to 30 min. When the annealing time is within the above range, the second perovskite component can form a complete passivation layer and the decomposition problem of the passivation layer can be reduced.

[0205] The film formation method of the first electrode 1, the first charge transport layer 2, the second charge transport layer 4, and the second electrode 5 is not specifically limited, and a film formation method known in the art may be used, for example, chemical bath deposition, chemical vapor deposition, electrochemical deposition, physical epitaxial growth, thermal evaporation, atomic layer deposition, magnetron sputtering, precursor liquid spin coating, precursor liquid slit coating, precursor liquid blade coating, mechanical pressing, sol-gel method, pulsed laser deposition, etc.

[0206] [Perovskite layer]

[0207] Seventhly, the embodiments of the present application further provide another perovskite layer (referred to herein as perovskite layer II for distinction), which can be used in perovskite cells and will be described below with reference to the accompanying drawings.

[0208] The perovskite layer includes a central portion and a passivation portion located on at least a portion of the surface of the central portion. The central portion includes perovskite crystals. The passivation portion includes a first passivation portion located on the upper and / or lower surface of the central portion along the thickness direction, and a second passivation portion located on the outer periphery of the central portion. The first passivation portion and the second passivation portion each independently include a passivation material, which includes one or more of a lead-based perovskite material, lead sulfide, silicon carbide, an oxide, a polymer, and an organic small molecule.

[0209] By applying a passivation material to the upper and / or lower surfaces of the middle portion along the thickness direction, as well as the outer periphery of the middle portion, the defect state density of the perovskite layer can be reduced, non-radiative recombination and impurity scattering can be minimized, and the stability of the battery device can be improved. Lead-based perovskite materials, lead sulfide, silicon carbide, oxides, polymers, and organic small molecules have passivation capabilities and can also transport carriers, thereby enabling the battery device to achieve high photoelectric conversion efficiency.

[0210] Figures 3 and 4 are schematic diagrams of the structure of a perovskite cell using a perovskite layer II. The perovskite layer 3 includes a middle portion 32 and a passivation portion 33 located on at least a portion of the surface of the middle portion 32.

[0211] As shown in FIG. 3 , in some embodiments, the passivation portion 33 may include a first passivation portion 331 located on both the upper and lower surfaces of the middle portion 32 and a second passivation portion 332 located on the outer circumference of the middle portion 32 .

[0212] As shown in FIG. 4 , in some embodiments, the passivation portion 33 may include a first passivation portion 331 located on the upper surface of the middle portion 32 along the thickness direction and a second passivation portion 332 located on the outer circumference of the middle portion 32 .

[0213] In other embodiments, the passivation portion 33 may further include a first passivation portion 331 located on the lower surface of the middle portion 32 along the thickness direction and a second passivation portion 332 located on the outer circumference of the middle portion 32 .

[0214] The upper surface of the middle portion along the thickness direction may be a surface of the middle portion away from the light incident side along the thickness direction, and the lower surface of the middle portion along the thickness direction may be a surface of the middle portion along the thickness direction close to the light incident side.

[0215] In some embodiments, a surface of the middle portion away from the light incident side in the thickness direction (i.e., the upper surface) and the outer peripheral surface of the middle portion are both provided with a passivation material, thereby improving the stability and oxidation resistance of the prepared battery device.

[0216] In some embodiments, the ratio of the thickness of the first passivation portion 331 to the thickness of the middle portion 32 may be 1:5-1:20, optionally 1:6.5-1:15, or 1:6.5-1:12. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0217] The thickness of the first passivation portion 331 refers to the thickness of the first passivation portion located on one of the two surfaces of the middle portion 32 along the thickness direction.

[0218] In some embodiments, the ratio of the thickness of the second passivation portion to the thickness of the middle portion 32 may be 1:5-1:20, optionally 1:6.5-1:15, or 1:6.5-1:12. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0219] The thickness of the second passivation portion 332 refers to the thickness of the second passivation portion located on one of the four surfaces (ie, the outer peripheral surface) of the middle portion 32 in two directions perpendicular to the thickness direction.

[0220] In some embodiments, the thickness of the middle portion may be 400 nm to 1000 nm.

[0221] In some embodiments, the oxide may include one or more of lead oxide, silicon oxide, aluminum oxide, and tin oxide, which can not only improve the stability of the battery device, but also promote carrier transport and improve the photoelectric conversion efficiency of the battery device.

[0222] In some embodiments, the polymer may include one or more homopolymers and copolymers of at least one monomer selected from vinyl chloride, thiophene and its derivatives, carbazole and its derivatives, and styrene sulfonic acid. For example, the polymer may include one or more selected from polyvinyl chloride, polythiophene, polycarbazole, poly(3,4-ethylenedioxythiophene), and poly(styrene sulfonic acid). This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0223] In some embodiments, the organic small molecule may include a compound containing at least one of a halogen atom and a heteroatom, wherein the heteroatom includes one or more of N, S, and O. Optionally, the molecular weight of the organic small molecule is less than 2000.

[0224] Organic small molecules include halogen atoms and / or heteroatoms. Halogen atoms and heteroatoms have greater electronegativity and higher charge density, and can interact with metal cations in perovskite crystals to form ligands. The molecular size of organic small molecules is generally larger than the maximum ionic radius of the cations in the perovskite crystal, making it difficult for them to enter the perovskite crystal lattice. Therefore, when the perovskite layer is crystallized, the organic small molecules can exist as impurities and can be detached to the grain boundaries and surfaces of the perovskite crystals, thereby passivating grain boundary defects and surface defects.

[0225] In some embodiments, the organic small molecule may include one or more of alkylamines and derivatives thereof, aromatic amines and derivatives thereof, nitrogen heterocyclic compounds and derivatives thereof, thiophene and derivatives thereof, carbazole and derivatives thereof, pentafluoroiodobenzene and derivatives thereof. The derivative of a compound generally refers to a substance after an atom or atomic group in the compound is replaced by another atom or atomic group. As an example, the organic small molecule may include one or more of phenylethylamine iodide, 2-(4-fluorophenyl)ethylamine hydroiodide, isobutylamine, 1-aminopentane, trimethylammonium bromide, tetramethylphosphonic acid carbazole, vinylcarbazole, 3,4-ethylenedioxythiophene, and styrenesulfonate. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0226] In some embodiments, the perovskite crystals in the middle portion may include the perovskite crystals provided in the first aspect of the embodiment of the present application.

[0227] [Perovskite battery]

[0228] In an eighth aspect, the embodiments of the present application also provide another perovskite battery.

[0229] As shown in Figures 3 and 4, the perovskite cell includes a first electrode 1, a second electrode 5, a perovskite layer 3, a first charge transport layer 2, and a second charge transport layer 4. The first electrode 1 is close to the light incident side, the perovskite layer 3 is located between the first electrode 1 and the second electrode 5, the first charge transport layer 2 is located between the first electrode 1 and the perovskite layer 3, and the second charge transport layer 4 is located between the second electrode 5 and the perovskite layer 3. The perovskite layer 3 includes another perovskite layer (i.e., perovskite layer II) provided in the seventh aspect of the embodiment of the present application, so the perovskite cell can have high stability and high photoelectric conversion efficiency.

[0230] In some embodiments, the first charge transport layer 2 is a hole transport layer, the second charge transport layer 4 is an electron transport layer, and the LUMO energy level of the first passivation portion 331 is lower than the CBM energy level of the intermediate portion 32. This facilitates carrier transport and improves the photoelectric conversion efficiency of the battery device.

[0231] In some embodiments, the first charge transport layer 2 is an electron transport layer, the second charge transport layer 4 is a hole transport layer, and the HOMO energy level of the first passivation portion 331 is greater than the VBM energy level of the intermediate portion 32. This facilitates carrier transport and improves the photoelectric conversion efficiency of the battery device.

[0232] In some embodiments, the first charge transport layer 2 is a hole transport layer, the second charge transport layer 4 is an electron transport layer, and the passivation portion 33 includes a first passivation portion 331 located on the surface of the middle portion 32 away from the first charge transport layer 2 and a second passivation portion 332 located on the outer peripheral surface of the middle portion 32. The LUMO energy level of the first passivation portion 331 is lower than the CBM energy level of the middle portion 32. This facilitates carrier transport and improves the photoelectric conversion efficiency of the battery device.

[0233] In some embodiments, the first charge transport layer 2 is an electron transport layer, the second charge transport layer 4 is a hole transport layer, and the passivation portion 33 includes a first passivation portion 331 located on the surface of the middle portion 32 away from the first charge transport layer 2 and a second passivation portion 332 located on the outer peripheral surface of the middle portion 32. The HUMO energy level of the first passivation portion 331 is greater than the VBM energy level of the middle portion 32. This facilitates carrier transport and improves the photoelectric conversion efficiency of the battery device.

[0234] The other components and structures of the perovskite battery can refer to the perovskite battery provided in the fifth aspect of the embodiment of the present application and will not be described in detail here.

[0235] [Method for preparing perovskite battery]

[0236] In a ninth aspect, the embodiments of the present application also provide a method for preparing the perovskite battery provided in the eighth aspect of the embodiments of the present application.

[0237] The method includes the following steps: providing a first electrode; forming a first charge transport layer on the first electrode; forming a perovskite layer on the first charge transport layer; forming a second charge transport layer on the perovskite layer; and forming a second electrode on the second charge transport layer.

[0238] In some embodiments, a method of forming the perovskite layer on the first charge transport layer may include a solution method, a hydrothermal method, a vapor deposition method, and the like.

[0239] In some embodiments, the step of forming a perovskite layer on the first charge transport layer includes the following steps: providing a passivation material and a precursor solution for forming the middle portion; mixing the passivation material and the precursor solution for forming the middle portion and applying them to the first charge transport layer to form the perovskite layer, and the molar ratio of the passivation material to the precursor for forming the middle portion (i.e., perovskite crystal) is 0.01:1-0.25:1, and can be optionally 0.01:1-0.1:1.

[0240] By adjusting the molar ratio of the passivation material to the precursor for forming the middle portion within the above range, a first passivation portion can be formed on the upper surface and / or lower surface of the middle portion along the thickness direction, and a second passivation portion can be formed on the outer peripheral surface of the middle portion at the same time.

[0241] In some embodiments, the step of forming a perovskite layer on the first charge transport layer includes the following steps: providing a precursor solution for forming the middle portion, the precursor solution for forming the middle portion is obtained by mixing a first precursor solution and a second precursor solution, the first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent, and the second precursor solution includes a second solvent and a C-site precursor compound CX dissolved in the second solvent. The A-position precursor compounds AX, PbX2 and a third component, the third component includes at least one substituted alkyl group selected from the group consisting of sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt and thiol group, and the molecular size of the third component is greater than a first threshold value, the first threshold value represents the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution; the precursor solution for forming the middle part is coated on the first charge transport layer to form a thin film; the solvent in the thin film is removed to form the middle part; the passivation material provided in the embodiment of the present application is applied to the upper surface and the outer peripheral surface of the middle part to complete the preparation of the perovskite layer.

[0242] Thereby, the perovskite crystal formed in the middle portion may include the perovskite crystal provided by the first aspect of the embodiment of the present application.

[0243] Optionally, the method of applying the passivation material on the upper surface and the outer peripheral surface of the middle portion includes a vapor deposition method.

[0244] In some embodiments, before coating the precursor solution for forming the middle portion on the first charge transport layer to form a thin film, the process further includes applying the passivation material provided in the embodiments of the present application on the first charge transport layer.

[0245] Optionally, the method of applying the passivation material on the first charge transport layer comprises a vapor deposition method.

[0246] The film formation method of the first electrode, the first charge transport layer 2, the second charge transport layer 4, and the second electrode 5 is not subject to specific restrictions, and a film formation method known in the art can be used, for example, chemical bath deposition, chemical vapor deposition, electrochemical deposition, physical epitaxial growth, thermal evaporation, atomic layer deposition, magnetron sputtering, precursor liquid spin coating, precursor liquid slit coating, precursor liquid scraping, mechanical pressing, sol-gel method, pulsed laser deposition, etc.

[0247] The perovskite cell provided in the embodiments of the present application can be used alone as a single-junction perovskite cell, or can be made into a stacked cell with perovskite-type or other types of perovskite cells, such as a perovskite-perovskite stacked cell or a perovskite-crystalline silicon stacked cell.

[0248] [Photovoltaic panels]

[0249] An embodiment of the present application also provides a photovoltaic module, which includes the perovskite cell provided in the embodiment of the present application or the perovskite cell prepared by the method provided in the embodiment of the present application. The perovskite cell can be used as a power source for the photovoltaic module after processes such as series and parallel connection and packaging.

[0250] In some embodiments, the photovoltaic module includes a single-junction perovskite cell, a perovskite-perovskite tandem cell, or a perovskite-crystalline silicon tandem cell provided in the embodiments of the present application.

[0251] [Electrical devices]

[0252] An embodiment of the present application also provides an electrical device, which includes one or more of the perovskite cell provided in the embodiment of the present application, the perovskite cell prepared by the method provided in the embodiment of the present application, and the photovoltaic module provided in the embodiment of the present application. The above-mentioned perovskite cell and photovoltaic module can be used to supply power to the electrical device.

[0253] In some embodiments, the power-consuming device may be a common device including the perovskite cell or photovoltaic module provided in the embodiments of the present application, such as equipment used in the fields of communications, transportation, industry and agriculture, lighting, etc. As examples, the power-consuming device may include satellites, communications equipment, traffic lights, lighthouses, wireless telephone booths, monitoring equipment for oil drilling, power systems, camping lanterns, electric vehicles, and electronic device chargers.

[0254] Example

[0255] The following examples describe the present disclosure in more detail and are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further processing, and all instruments used in the examples are commercially available.

[0256] Example 1-1

[0257] Preparation of the first electrode

[0258] Take a 2.0 cm × 2.0 cm FTO conductive glass, remove 0.35 cm of FTO at each end by laser etching to expose the glass substrate; ultrasonically clean the laser-etched FTO conductive glass several times with water, acetone, and isopropyl alcohol in sequence; blow the cleaned FTO conductive glass dry with a nitrogen gun, and then place it in a UV ozone machine for further cleaning and set aside.

[0259] Preparation of hole transport layer

[0260] The FTO conductive glass was placed on a suction cup, and the PEDOT:PSS aqueous solution was rotated on the FTO conductive glass at a speed of 5000 rpm for 30 seconds. It was then placed on a heating table and annealed at 150°C for 10 minutes. After cooling to room temperature (25°C), a hole transport layer with a thickness of 50 nm was obtained, which was then placed in an ultra-purified glove box filled with nitrogen.

[0261] Preparation of perovskite layer

[0262] 335 mg of SnI2 and 216 mg of formamidine iodide (FAI) were dissolved in a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio of 4:1) to obtain a formamidine tin iodide (FASnI3) precursor solution. The concentration of FASnI3 was 1 mol / L. 414 mg of PbI2 and 85 mg of methylamine iodide (MAI) were dissolved in a mixed solvent of dimethylphosphonic acid, DMF, and DMSO to obtain a methylamine lead iodide (MAPbI3) precursor solution. The concentration of MAPbI3 was 1 mol / L. The volume ratio of DMF and DMSO was 4:1, and the molar ratio of dimethylphosphonic acid to PbI2 was 0.02:1. The FASnI3 and MAPbI3 precursor solutions were mixed by stirring to obtain a precursor solution.

[0263] The precursor solution was spin-coated onto the hole transport layer at 1000 rpm for 10 seconds, then at 4000 rpm for 40 seconds. At the 30th second mark, 400 μL of chlorobenzene was quickly added dropwise. The layer was then annealed at 100°C for 10 minutes and cooled to room temperature to produce a perovskite layer with a thickness of 800 nm. The perovskite grains in the perovskite layer consisted of a core portion and a passivation layer located on at least a portion of the core portion's surface. The perovskite component in the core portion was a tin-lead mixed perovskite material, while the perovskite component in the passivation layer was a lead-based perovskite material, namely MAPbI3.

[0264] Preparation of electron transport layer

[0265] 40 μL of PCBM solution was spun on the surface of the perovskite layer at 4000 rpm for 30 seconds to obtain an electron transport layer with a thickness of 25 nm, and then a BCP layer with a thickness of 15 nm was evaporated.

[0266] Preparation of the second electrode

[0267] The sample obtained above was placed in an evaporation machine, and an Ag electrode was evaporated to a thickness of 10 nm to obtain a battery device.

[0268] Examples 1-2 to 1-6

[0269] The preparation of the battery device is the same as that of Example 1-1, except that the molar ratio of dimethylphosphonic acid to PbI2 is different when preparing the methylamine lead iodide (MAPbI3) precursor solution. The specific parameters are detailed in Table 1.

[0270] Examples 1-7 to 1-11

[0271] The preparation of the battery device is the same as that of Example 1-1, except that different third components are used in the preparation of the methylamine lead iodide (MAPbI3) precursor solution. The types of the third components are detailed in Table 1.

[0272] Comparative Example 1-1

[0273] Except for the different preparation process of the perovskite layer, the preparation of the battery device is the same as that of Example 1-1.

[0274] 335 mg of SnI2 and 216 mg of formamidine iodide (FAI) were dissolved in a mixed solvent consisting of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio of 4:1) to obtain a formamidine tin iodide (FASnI3) precursor solution, and the concentration of FASnI3 was 1 mol / L. 414 mg of PbI2 and 85 mg of methylamine iodide (MAI) were dissolved in a mixed solvent consisting of DMF and DMSO (volume ratio of 4:1) to obtain a methylamine lead iodide (MAPbI3) precursor solution, and the concentration of MAPbI3 was 1 mol / L. The FASnI3 precursor solution and the MAPbI3 precursor solution were mixed by stirring to obtain (FASnI3) 0.5 (MAPbI3) 0.5 Precursor solution.

[0275] Spin coating on the hole transport layer (FASnI3) 0.5 (MAPbI3) 0.5 The precursor solution was spin-coated at 1000 rpm for 10 seconds and then at 4000 rpm for 40 seconds, and 400 μL of chlorobenzene was quickly added at 30 seconds. After that, the solution was annealed at 100°C for 10 minutes and cooled to room temperature to obtain a perovskite layer.

[0276] Comparative Example 1-2

[0277] Except for the different preparation process of the perovskite layer, the preparation of the battery device is the same as that of Example 1-1.

[0278] The prepared FTO / PEDOT:PS substrate was placed in an evaporator, and then 335 mg of stannous iodide (evaporation source 1), 216 mg of formamidine iodide (evaporation source 2), 414 mg of lead iodide (evaporation source 3), 85 mg of methylamine iodide (evaporation source 4), 100 mg of lead iodide (evaporation source 5), and 32 mg of methylamine iodide (evaporation source 6) were added to different evaporation sources.

[0279] The stannous iodide in evaporation source 1 and the lead iodide in evaporation source 3 were heated at 270°C for evaporation and deposited on the substrate. Then, the formamidine iodide in evaporation source 2 and the methylamine iodide in evaporation source 4 were heated at 140°C for evaporation and deposited on the substrate. After the deposition, the mixture was annealed at 100°C for 10 minutes in a nitrogen environment to obtain MA. 0.5 FA 0.5 Pb 0.5 Sn 0.5 I3. Then, the lead iodide in the evaporation source 5 is heated at 270°C and evaporated and deposited onto the MA 0.5 FA 0.5 Pb 0.5 Sn 0.5Then, methylamine iodide in evaporation source 6 is heated at 140°C and evaporated onto MA 0.5 FA 0.5 Pb 0.5 Sn 0.5 After the deposition is completed, the perovskite layer is annealed in a nitrogen environment at 100°C for 10 minutes to obtain the perovskite layer. The perovskite grains in the perovskite layer include a core and a passivation layer located on at least part of the surface of the core. The perovskite component in the core is MA 0.5 FA 0.5 Pb 0.5 Sn 0.5 I3, the perovskite component in the passivation layer is MAPbI3.

[0280] The performance of the battery devices provided in Examples 1-1 to 1-11 and Comparative Examples 1-1 to 1-2 was tested. The results are shown in Table 1.

[0281] The test standard refers to IEC61215. Crystalline silicon solar cells are used to calibrate the light intensity to the intensity of one sun, AM 1.5. During the test, the battery device is connected to a digital source meter and tested under light to obtain an IV curve. Based on the IV curve and the data fed back by the test equipment, the short-circuit current Jsc (unit: mA / cm 2 ), open-circuit voltage Voc (V), maximum light output current Jmpp (mA), and maximum light output voltage Vmpp (V). The fill factor (FF) of the perovskite cell (in %) was calculated using the formula FF = Jsc × Voc / (Jmpp × Vmpp). The photoelectric conversion efficiency (PCE) of the perovskite cell (in %) was calculated using the formula PCE = (Jsc × Voc × FF) / Pw, where Pw represents the input power (in mW).

[0282] The test instrument can be Guangyan’s solar simulator.

[0283] Table 1

[0284] It can be seen from the test results of Examples 1-1 to 1-11 and Comparative Example 1-1 that by integrally forming perovskite grains with a core-shell structure, the perovskite cell can have high stability and high photoelectric conversion efficiency.

[0285] The test results of Comparative Examples 1-2 show that vapor deposition of a passivation layer on the surface of the prepared tin-lead mixed perovskite grains results in the formation of an interface between the core and shell of the final perovskite grains. This interface affects carrier transport and has little effect on improving the stability of the perovskite crystals. Therefore, the perovskite cells prepared in Comparative Examples 1-2 exhibit low stability and photoelectric conversion efficiency.

[0286] Example 2-1

[0287] Except for the different preparation process of the perovskite layer, the preparation of the battery device is the same as that of Example 1-1.

[0288] Preparation of perovskite layer

[0289] 335mg SnI2 and 216mg of formamidine iodide (FAI) were dissolved in a mixed solvent consisting of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio of 4:1) to obtain a formamidine tin iodide (FASnI3) precursor solution, with a FASnI3 concentration of 1 mol / L. 414mg PbI2 and 85mg of methylamine iodide (MAI) were dissolved in a mixed solvent consisting of DMF and DMSO (volume ratio of 4:1) to obtain a methylamine lead iodide (MAPbI3) precursor solution, with a MAPbI3 concentration of 1 mol / L. The FASnI3 precursor solution and the MAPbI3 precursor solution were mixed by stirring, and 3ml of PbS colloidal quantum dot solution dissolved in n-octane was added. After stirring for 10 minutes, the n-octane in the solution was washed away with isopropanol to obtain (FASnI3) 0.5 (MAPbI3) 0.5 Precursor solution.

[0290] Spin coating on the hole transport layer (FASnI3) 0.5 (MAPbI3) 0.5 The precursor solution was spin-coated at 1000 rpm for 10 seconds and then at 4000 rpm for 40 seconds, and 400 μL of chlorobenzene was quickly added at 30 seconds. After that, the solution was annealed at 100°C for 10 minutes and cooled to room temperature to obtain a perovskite layer.

[0291] The perovskite layer includes a middle portion and a passivation portion. The passivation portion includes a first passivation portion located on an upper surface and a lower surface of the middle portion in a thickness direction and a second passivation portion located on an outer peripheral surface of the middle portion.

[0292] Examples 2-2 to 2-5

[0293] The preparation of the battery device is the same as that of Example 2-1, except that (FASnI3) is prepared 0.5 (MAPbI3) 0.5 When preparing the precursor solution, the amount of PbS colloidal quantum dot solution used is different. The specific parameters are shown in Table 2.

[0294] Examples 2-6 to 2-10

[0295] The preparation of the battery device is the same as that of Example 2-1, except that (FASnI3) is prepared 0.5 (MAPbI3) 0.5When preparing the precursor solution, different passivation materials are used. The specific parameters are shown in Table 2.

[0296] Comparative Example 2-1

[0297] The preparation of the battery device is the same as that of Example 2-1, except that (FASnI3) is prepared 0.5 (MAPbI3) 0.5 When preparing the precursor solution, the amount of PbS colloidal quantum dot solution used is different. The specific parameters are shown in Table 2.

[0298] The performance of the battery devices provided in Examples 2-1 to 2-10 and Comparative Example 2-1 was tested. The results are shown in Table 2.

[0299] Table 2

[0300] It can be seen from the test results in Table 2 that by providing passivation material on the upper surface and / or lower surface of the middle part of the perovskite layer along the thickness direction and the outer peripheral surface of the middle part, the perovskite cell can have high stability and high photoelectric conversion efficiency.

[0301] It can be seen from the test results of Comparative Example 2-1 that when the outer surface of the perovskite layer does not have a passivation material, the stability and photoelectric conversion efficiency of the prepared perovskite cell are relatively low.

[0302] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A perovskite crystal, wherein: The perovskite crystal includes one or more perovskite grains, each of which includes a core and a passivation layer located on at least a portion of the surface of the core. The core portion includes a first perovskite component, and the passivation layer includes a second perovskite component. The first perovskite component includes one or more of ABX3 and A2CDX6, and the second perovskite component includes one or more of APbX3. A in ABX3, A2CDX6 and APbX3 independently represents a monovalent inorganic cation, an organic cation or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation or an organic-inorganic mixed cation, X in ABX3, A2CDX6 and APbX3 independently represents a monovalent inorganic anion, an organic anion or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation or an organic-inorganic mixed cation.

2. The perovskite crystal according to claim 1, wherein The passivation layer and the core portion.

3. The perovskite crystal according to any one of claims 1 to 2, wherein: The perovskite crystal also includes a third component, which is located on the surface and / or grain boundary of the perovskite crystal. The third component includes an alkyl group substituted with at least one of sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt, and thiol group, and the molecular size of the third component is greater than a first threshold value, and the first threshold value represents the maximum value of the ionic radius of the cations of the first perovskite component and the second perovskite component.

4. The perovskite crystal according to claim 3, wherein: The third component includes one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboric acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

5. The perovskite crystal according to any one of claims 1 to 4, wherein: The ratio of the thickness of the passivation layer to the grain size of the perovskite grains is greater than 0 and less than or equal to 0.33:1; and / or, The thickness of the passivation layer is 1 nm-100 nm.

6. The perovskite crystal according to any one of claims 1 to 5, wherein: The grain size of the perovskite grains is 300nm-1000nm; and / or, The passivation layer is located on 80%-100% of the surface of the core portion.

7. The perovskite crystal according to any one of claims 1 to 6, wherein: B includes Pb 2+ Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ 、Zn 2+ ,Ge 2+ , Fe 2+ 、Co 2+ 、Ni 2+ One or more of .

8. The perovskite crystal according to any one of claims 1 to 7, wherein: A in ABX3, A2CDX6 and APbX3 independently comprises CH3NH3 + 、CH3CH2NH3 + 、CH(NH2)2 + , Li + 、Na + , K + , Rb + , Cs + One or more of; and / or, X in ABX3, A2CDX6 and APbX3 each independently represents a halogen ion; and / or, C represents a monovalent metal cation; and / or, D represents a trivalent metal cation.

9. A precursor solution for preparing the perovskite crystal according to any one of claims 1 to 8, wherein: The precursor solution is obtained by mixing a first precursor solution and a second precursor solution, The first precursor solution includes a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or includes a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent. The second precursor solution includes a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, wherein the third component includes an alkyl group substituted with at least one of sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt and thiol group, and the molecular size of the third component is greater than a first threshold value, and the first threshold value represents the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution.

10. The precursor solution according to claim 9, wherein The third component includes one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboric acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid; and / or, The molar ratio of the third component to PbX2 is 0.005:1-0.1:1; and / or, The first solvent comprises dimethylformamide and dimethyl sulfoxide; and / or, The second solvent includes dimethylformamide and dimethyl sulfoxide.

11. A perovskite layer, wherein: The perovskite layer comprises the perovskite crystal according to any one of claims 1 to 8.

12. A method for preparing a perovskite layer, wherein: The steps include: providing a substrate; Providing a precursor solution for forming a perovskite layer, wherein the precursor solution for forming the perovskite layer is obtained by mixing a first precursor solution and a second precursor solution, wherein the first precursor solution comprises a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or comprises a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent, and the second precursor solution comprises a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, wherein the third component comprises an alkyl group substituted with at least one of a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, a boric acid group, a cyano group, an amine group, a quaternary ammonium salt and a thiol group, and the molecular size of the third component is greater than a first threshold value, and the first threshold value represents the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution; Applying the precursor solution for forming a perovskite layer on the substrate to form a thin film; The solvent in the film is removed to form a perovskite layer, wherein the perovskite layer includes perovskite crystals, the perovskite crystals include one or more perovskite grains, the perovskite grains include a core portion and a passivation layer located on at least a portion of the surface of the core portion, the core portion includes a first perovskite component, the passivation layer includes a second perovskite component, the first perovskite component includes one or more of ABX3, A2CDX6, the second perovskite component includes one or more of APbX3, A in ABX3, A2CDX6 and APbX3 independently represents a monovalent inorganic cation, an organic cation or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation or an organic-inorganic mixed cation, X in ABX3, A2CDX6 and APbX3 independently represents a monovalent inorganic anion, an organic anion or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation or an organic-inorganic mixed cation.

13. The method according to claim 12, wherein: The third component includes one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboric acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid; and / or, The molar ratio of the third component to PbX2 is 0.005:1-0.1:1; and / or, The first solvent comprises dimethylformamide and dimethyl sulfoxide; and / or, The second solvent includes dimethylformamide and dimethyl sulfoxide.

14. The method according to any one of claims 12 to 13, wherein: The step of removing the solvent in the thin film to form the perovskite layer includes the following steps: transferring the substrate formed with the thin film to a hot stage for annealing to form the perovskite layer.

15. A perovskite battery, comprising: A first electrode, close to the light incident side; a second electrode; a perovskite layer, located between the first electrode and the second electrode; a first charge transport layer, located between the first electrode and the perovskite layer; as well as a second charge transport layer, located between the second electrode and the perovskite layer, in, The perovskite layer comprises the perovskite layer according to claim 10, and a perovskite layer prepared by the method according to any one of claims 12-14.

16. A method for preparing a perovskite battery, wherein: The steps include: providing a first electrode; forming a first charge transport layer on the first electrode; Providing a precursor solution for forming a perovskite layer, wherein the precursor solution for forming the perovskite layer is obtained by mixing a first precursor solution and a second precursor solution, wherein the first precursor solution comprises a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or comprises a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent, and the second precursor solution comprises a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, wherein the third component comprises an alkyl group substituted with at least one of a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, a boric acid group, a cyano group, an amine group, a quaternary ammonium salt and a thiol group, and the molecular size of the third component is greater than a first threshold value, and the first threshold value represents the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution; Applying the precursor solution for forming the perovskite layer on the first charge transport layer to form a thin film; Removing the solvent in the film to form a perovskite layer, wherein the perovskite layer includes perovskite crystals, the perovskite crystals include one or more perovskite grains, the perovskite grains include a core portion and a passivation layer located on at least a portion of the surface of the core portion, the core portion includes a first perovskite component, the passivation layer includes a second perovskite component, the first perovskite component includes one or more of ABX3, A2CDX6, and the second perovskite component includes one or more of APbX3, A in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, B represents a divalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, X in ABX3, A2CDX6, and APbX3 independently represents a monovalent inorganic anion, an organic anion, or an organic-inorganic mixed anion, C represents a monovalent inorganic cation, an organic cation, or an organic-inorganic mixed cation, and D represents a trivalent inorganic cation, an organic cation, or an organic-inorganic mixed cation; forming a second charge transport layer on the perovskite layer; A second electrode is formed on the second charge transport layer.

17. The method according to claim 16, wherein: The third component includes one or more of dimethylphosphonic acid, 2,2-dimethylethyleneboric acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid; and / or, The molar ratio of the third component to PbX2 is 0.005:1-0.1:1; and / or, The first solvent comprises dimethylformamide and dimethyl sulfoxide; and / or, The second solvent includes dimethylformamide and dimethyl sulfoxide.

18. The method according to any one of claims 16 to 17, wherein: The step of removing the solvent in the thin film to form a perovskite layer includes the following steps: transferring the first electrode formed with the thin film to a hot stage for annealing to form a perovskite layer.

19. A perovskite layer, wherein: The perovskite layer includes a middle portion and a passivation portion located on at least a portion of the surface of the middle portion; The intermediate portion includes a perovskite crystal; The passivation portion includes a first passivation portion located on the upper surface and / or lower surface of the middle portion along the thickness direction and a second passivation portion located on the outer peripheral surface of the middle portion; The first passivation part and the second passivation part independently include a passivation material, and the passivation material includes one or more of a lead-based perovskite material, lead sulfide, silicon carbide, an oxide, a polymer, and an organic small molecule.

20. The perovskite layer according to claim 19, wherein The ratio of the thickness of the first passivation portion to the thickness of the middle portion is 1:5-1:20; and / or, The ratio of the thickness of the second passivation portion to the thickness of the middle portion is 1:5-1:20; and / or, The thickness of the middle portion is 400nm-1000nm.

21. The perovskite layer according to any one of claims 19 to 20, wherein: The oxide includes one or more of lead oxide, silicon oxide, aluminum oxide, and tin oxide; and / or, The polymer includes one or more of homopolymers and copolymers of at least one monomer selected from vinyl chloride, thiophene and its derivatives, carbazole and its derivatives, and styrene sulfonic acid; and / or, The organic small molecules include compounds containing at least one of a halogen atom and a heteroatom, and the heteroatom includes one or more of N, S, and O.

22. The perovskite layer according to any one of claims 19 to 21, wherein: The perovskite crystal comprises the perovskite crystal according to any one of claims 1 to 8.

23. A perovskite battery, comprising: A first electrode, close to the light incident side; a second electrode; a perovskite layer, located between the first electrode and the second electrode; a first charge transport layer, located between the first electrode and the perovskite layer; as well as a second charge transport layer, located between the second electrode and the perovskite layer, in, The perovskite layer comprises the perovskite layer according to any one of claims 19-22.

24. The perovskite cell according to claim 23, wherein: The first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, and the LUMO energy level of the first passivation portion is lower than the CBM energy level of the intermediate portion; or The first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, and a HOMO energy level of the first passivation portion is greater than a VBM energy level of the intermediate portion.

25. The perovskite cell according to claim 24, wherein: The first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, the passivation portion includes a first passivation portion located on a surface of the middle portion away from the first charge transport layer and a second passivation portion located on an outer peripheral surface of the middle portion, and the LUMO energy level of the first passivation portion is lower than the CBM energy level of the middle portion; or The first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, the passivation portion includes a first passivation portion located on the surface of the middle portion away from the first charge transport layer and a second passivation portion located on the outer peripheral surface of the middle portion, and the HOMO energy level of the first passivation portion is greater than the VBM energy level of the middle portion.

26. A method for preparing a perovskite cell according to any one of claims 23 to 25, wherein: The steps include: providing a first electrode; forming a first charge transport layer on the first electrode; forming a perovskite layer on the first charge transport layer; forming a second charge transport layer on the perovskite layer; A second electrode is formed on the second charge transport layer.

27. The method according to claim 26, wherein: Methods for forming a perovskite layer on the first charge transport layer include a solution method, a hydrothermal method, and a vapor deposition method.

28. The method according to claim 26 or 27, wherein: The step of forming a perovskite layer on the first charge transport layer comprises the following steps: providing a passivation material and a precursor solution for forming the intermediate portion; The passivation material and the precursor solution for forming the intermediate portion are mixed and applied to the first charge transport layer to form a perovskite layer, The molar ratio of the passivation material to the precursor for forming the middle portion is 0.01:1-0.25:

1.

29. The method according to claim 26, wherein: The step of forming a perovskite layer on the first charge transport layer comprises the following steps: Providing a precursor solution for forming a middle portion, wherein the precursor solution for forming the middle portion is obtained by mixing a first precursor solution and a second precursor solution, the first precursor solution comprising a first solvent and an A-site precursor compound AX and a B-site precursor compound BX2 dissolved in the first solvent, or comprising a first solvent and an A-site precursor compound AX, a C-site precursor compound CX and a D-site precursor compound DX3 dissolved in the first solvent, the second precursor solution comprising a second solvent and an A-site precursor compound AX, PbX2 and a third component dissolved in the second solvent, the third component comprising an alkyl group substituted with at least one of sulfonic acid group, phosphoric acid group, carboxylic acid group, boric acid group, cyano group, amine group, quaternary ammonium salt and thiol group, and the molecular size of the third component is greater than a first threshold value, the first threshold value representing the maximum value of the ionic radius of the cations of the precursor compounds in the first precursor solution and the second precursor solution; Applying the precursor solution for forming the middle portion on the first charge transport layer to form a thin film; removing the solvent from the film to form a middle portion; A passivation material is applied to the upper surface and the outer peripheral surface of the middle portion to complete the preparation of the perovskite layer.

30. The method of claim 29, wherein: Before coating the precursor solution for forming the middle portion on the first charge transport layer to form a thin film, the method further includes applying a passivation material on the first charge transport layer.

31. A photovoltaic module, wherein: Including the perovskite battery according to claim 15, or the perovskite battery prepared by the method described in any one of claims 16-18, or the perovskite battery according to any one of claims 23-25, or the perovskite battery prepared by the method described in any one of claims 26-30.

32. An electrical device, wherein: It comprises one or more of the perovskite cell according to claim 15, the perovskite cell prepared by the method described in any one of claims 16-18, the perovskite cell according to any one of claims 23-25, the perovskite cell prepared by the method described in any one of claims 26-30, and the photovoltaic module according to claim 31, wherein the perovskite cell and the photovoltaic module are used to supply power to the electrical device.

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