Perovskite crystal, precursor solution, perovskite layer, perovskite battery, preparation method, photovoltaic module and power utilization device

Abstract

The invention provides a perovskite crystal, a precursor solution, a perovskite layer, a perovskite cell, a preparation method, a photovoltaic module and a power utilization device, the perovskite crystal comprises one or more perovskite crystal grains, and each perovskite crystal grain comprises a core part and a passivation layer located on at least part of the surface of the core part. The passivation layer and the core part are integrally formed, the core part comprises a first perovskite component, and the passivation layer comprises a second perovskite component. According to the invention, the perovskite cell has high stability and high photoelectric conversion efficiency.

Description

Technical Field

[0001] 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

[0002] 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 currently prepared 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. Summary of the invention

[0003] 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.

[0004] In a first aspect, the present application provides 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, and the passivation layer is formed integrally with the core.

[0005] 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.

[0006] 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 higher carrier transport ability, and also facilitating the energy level matching between the perovskite layer and the charge transport layer, thereby also facilitating the improvement of the photoelectric conversion efficiency of the battery device.

[0007] The core of the perovskite grain provided in the embodiment of the present application is formed integrally with the passivation layer, which can further improve the stability and oxidation resistance of the perovskite crystal, and can also promote carrier transport, thereby facilitating the battery device using it to have high stability and high photoelectric conversion efficiency.

[0008] Therefore, the perovskite cell using the perovskite crystal provided in the embodiment of the present application can have high stability and high photoelectric conversion efficiency.

[0009] In any embodiment, the perovskite crystal also 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.

[0010] In any embodiment, 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.

[0011] 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, and can be 0.02:1-0.14:1. In this way, the perovskite cell can have both high stability and high photoelectric conversion efficiency.

[0012] In any embodiment, the thickness of the passivation layer is 1 nm-100 nm, and can be 15 nm-56 nm, thereby enabling the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0013] In any embodiment, the grain size of the perovskite grains is 300nm-1000nm.

[0014] In any embodiment, the passivation layer is located on 80%-100% of the surface of the core, thereby helping the perovskite cell to have high stability.

[0015] 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, optionally, B includes Pb 2+ Sn 2+ One or two of, more optionally, B includes Sn 2+ Or include Pb 2+ and Sn 2+ .

[0016] 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, optionally, A in ABX3, A2CDX6 and APbX3 independently comprises CH3NH3 + 、CH3CH2NH3 + 、CH(NH2)2 + , Cs + One or more of .

[0017] In any embodiment, X in ABX3, A2CDX6 and APbX3 each independently represents a halogen ion, and optionally, X in ABX3, A2CDX6 and APbX3 each independently comprises F - , Cl - Br - ,I - More preferably, X in ABX3, A2CDX6 and APbX3 independently includes Cl - Br - ,I - One or more of .

[0018] In any embodiment, C represents a monovalent metal cation, optionally, C comprises Li + 、Na + , K +, Rb + , Cs + 、Ag + One or more of .

[0019] In any embodiment, D represents a trivalent metal cation, and optionally, D comprises In 3+ 、Bi 3+ , Sb 3+ One or more of .

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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 mixed precursor solution, due to the large molecular size of the third component, it cannot be located at 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+ The perovskite crystals are separated from the grain boundaries and surfaces to form core-shell structured perovskite grains, and the passivation layer of the perovskite grains formed integrally can play a role in passivating both grain boundary defects and surface defects.

[0024] 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 the third component can be reduced 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.

[0025] In any embodiment, 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.

[0026] In any embodiment, the molar ratio of the third component to PbX2 is 0.005: 1-0.1: 1, and can be optionally 0.01: 1-0.05: 1. By adjusting the molar ratio of the third component to PbX2 within the above range, the perovskite grains formed by crystallization 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 the photoelectric conversion efficiency of the perovskite battery.

[0027] In any embodiment, the first solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1.

[0028] In any embodiment, the second solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1.

[0029] A third aspect of the present application provides a perovskite layer, which includes the perovskite crystal of the first aspect of the present application.

[0030] 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.

[0031] 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 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.

[0032] The perovskite layer includes a perovskite crystal, and the perovskite crystal includes 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, and the passivation layer is formed integrally with the core portion. 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, 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.

[0033] 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.

[0034] In any embodiment, 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.

[0035] In any embodiment, the molar ratio of the third component to PbX2 is 0.005: 1-0.1: 1, and can be optionally 0.01: 1-0.05: 1. By adjusting the molar ratio of the third component to PbX2 within the above range, the perovskite grains formed by crystallization 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 the photoelectric conversion efficiency of the perovskite battery.

[0036] In any embodiment, the first solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1.

[0037] In any embodiment, the second solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1.

[0038] In any embodiment, the step of removing the solvent in the thin film to form a 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. Optionally, the annealing temperature is 80° C.-210° C. Optionally, the annealing time is 1 min-30 min.

[0039] 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 close to the light incident 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 comprises 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.

[0040] 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 a 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.

[0041] 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 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.

[0042] The perovskite layer includes a perovskite crystal, and the perovskite crystal includes 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, and the passivation layer is formed integrally with the core portion. 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, 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.

[0043] The perovskite cell prepared by the method provided in the embodiments of the present application can have high stability and high photoelectric conversion efficiency.

[0044] In any embodiment, 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.

[0045] In any embodiment, the molar ratio of the third component to PbX2 is 0.005: 1-0.1: 1, and can be optionally 0.01: 1-0.05: 1. By adjusting the molar ratio of the third component to PbX2 within the above range, the perovskite grains formed by crystallization 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 the photoelectric conversion efficiency of the perovskite battery.

[0046] In any embodiment, the first solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1.

[0047] In any embodiment, the second solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1.

[0048] 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. Optionally, the annealing temperature is 80° C.-210° C. Optionally, the annealing time is 1 min-30 min.

[0049] 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.

[0050] By providing the passivation material on the upper surface and / or the lower surface of the middle part along the thickness direction and the peripheral surface of the middle part, the defect state density of the perovskite layer can be reduced, the non-radiative recombination and impurity scattering can be reduced, 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 have a high photoelectric conversion efficiency.

[0051] 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, and can be 1:6.5-1:15. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0052] 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, and can be 1:6.5-1:15. This allows the perovskite cell to have both high stability and high photoelectric conversion efficiency.

[0053] In any embodiment, the thickness of the middle portion is 400nm-1000nm.

[0054] In any embodiment, the oxide includes 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.

[0055] In any embodiment, the polymer includes one or more of homopolymers and copolymers of at least one monomer of vinyl chloride, thiophene and its derivatives, carbazole and its derivatives, and styrene sulfonic acid, and optionally includes one or more of polyvinyl chloride, polythiophene, polycarbazole, poly(3,4-ethylenedioxythiophene), and poly(styrene sulfonic acid). Thus, the perovskite cell can have both high stability and high photoelectric conversion efficiency.

[0056] In any embodiment, the organic small molecule includes 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, and optionally includes one or more of phenethylamine iodide, 2-(4-fluorophenyl)ethylamine hydroiodide, isobutylamine, 1-aminopentane, trimethylammonium bromide, tetramethylphosphonic acid carbazole, vinyl carbazole, 3,4-ethylenedioxythiophene, and styrene sulfonate. Thus, the perovskite cell can have both high stability and high photoelectric conversion efficiency.

[0057] In any embodiment, the perovskite crystal includes the perovskite crystal of the first aspect of the present application.

[0058] In an eighth aspect, the present application provides another perovskite battery, 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 close to the light incident 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, the second charge transport layer is located between the second electrode and the perovskite layer, and the perovskite layer includes the perovskite layer of the seventh aspect of the present application.

[0059] 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 middle portion, thereby facilitating the transport of carriers and improving the photoelectric conversion efficiency of the battery device.

[0060] 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, thereby facilitating the transport of carriers and improving the photoelectric conversion efficiency of the battery device.

[0061] In any embodiment, 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 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 LUMO energy level of the first passivation portion is lower than the CBM energy level of the middle portion. This is beneficial to promote the transport of carriers and improve 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, 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. This is beneficial to promote the transport of carriers and improve the photoelectric conversion efficiency of the battery device.

[0063] 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.

[0064] In any embodiment, a method of forming a perovskite layer on the first charge transport layer includes a solution method, a hydrothermal method, and a vapor deposition method.

[0065] 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 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, wherein the molar ratio of the passivation material to the precursor for forming the middle portion is 0.01:1-0.25:1, and can be optionally 0.01:1-0.1:1. 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.

[0066] 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, 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 second precursor compound DX3 dissolved in the first solvent. A-position precursor compounds AX, PbX2 and a third component in two solvents, the third component includes at least one substituted alkyl selected from sulfonic acid, phosphoric acid, 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, 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 film; the solvent in the film is removed to form the middle part; a passivation material is applied to the upper surface and the peripheral surface of the middle part to complete the preparation of the perovskite layer. Thus, the perovskite crystals formed in the middle part can include the perovskite crystals of the first aspect of the present application.

[0067] In any embodiment, the method of applying the passivation material on the upper surface and the outer peripheral surface of the middle portion comprises a vapor deposition method.

[0068] In any embodiment, 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.

[0069] In any embodiment, the method of applying the passivation material on the first charge transport layer comprises a vapor deposition method.

[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] In order 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 implementation methods of the present application, and for ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0074] Figure 1 It is a schematic diagram of the structure of perovskite grains provided in some embodiments of the present application.

[0075] Figure 2 It is a schematic diagram of the structure of the perovskite battery provided in some embodiments of the present application.

[0076] Figure 3 It is a schematic diagram of the structure of the perovskite battery provided in other embodiments of the present application.

[0077] Figure 4 This is a schematic diagram of the structure of a perovskite battery provided in some other embodiments of the present application.

[0078] In the accompanying drawings, the drawings may not be drawn according to the actual 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; 312, passivation layer; 32, middle; 33, passivation; 331, first passivation; 332, second passivation. 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 specifically disclosed with appropriate reference to the accompanying drawings. However, there are 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 structures 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 descriptions 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] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a 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 a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present 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 real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it 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] If not otherwise specified, all embodiments and optional embodiments of the present application may be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of the present application.

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

[0083] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means 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), which means 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] If not 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 commonly understood 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 by various test methods commonly used in the art, for example, they can be measured according to the test methods given in this application. Unless otherwise specified, the test temperature of each parameter is 25°C.

[0087] The term "organic small molecule" adopts its common meaning in the art. Typically, an organic small molecule contains carbon atoms. And those skilled in the art will understand that the term "organic small molecule" does not usually include compounds that are mainly in ionic form, such as carbides, etc.

[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] Figure 1 It is a schematic diagram of the structure of perovskite grains provided in some embodiments of the present application.

[0091] like Figure 1 As shown, the perovskite crystal includes one or more perovskite grains 31 , and 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 , and the passivation layer 312 is formed integrally with 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 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.

[0095] The passivation layer and the core portion are formed integrally, which means that there is no interface between the passivation layer and the core portion, and the material of the passivation layer is different from the material of the core portion.

[0096] The perovskite crystal includes one or more perovskite grains, so the perovskite crystal can be either a single crystal or a polycrystalline.

[0097] The working principle of perovskite cells is generally as follows: under illumination, the perovskite layer absorbs photon energy, generates electron-hole pairs in its valence band, and the electrons are excited to the conduction band, leaving holes in the valence band. The conduction band energy level of the perovskite layer is generally higher than the conduction band energy level of the electron transport layer, so that electrons can be transferred from the conduction band position of the perovskite layer to the conduction band position of the electron transport layer, and then to the conductive electrode; the valence band energy level of the perovskite layer is generally lower than the valence band energy level of the hole transport layer, so that holes can be transferred to the conductive electrode through the hole transport layer. When the external circuit is connected, a complete loop is formed, generating photocurrent.

[0098] Perovskite crystals, such as tin-lead mixed perovskite crystals, have problems such as easy oxidation, non-uniform 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 will affect the carrier dynamics process.

[0099] Providing a passivation layer with a passivation 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 the carrier transport; at the same time, the defects at the grain boundaries of the perovskite grains cannot be passivated, which will affect 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, thereby affecting the photoelectric conversion efficiency of the battery device.

[0100] 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 higher carrier transport ability, and also facilitating the energy level matching between the perovskite layer and the charge transport layer, thereby also facilitating the improvement of the photoelectric conversion efficiency of the battery device.

[0101] The core of the perovskite grain provided in the embodiment of the present application is formed integrally with the passivation layer, which can further improve the stability and oxidation resistance of the perovskite crystal, and can also promote carrier transport, thereby facilitating the battery device using it to have high stability and high photoelectric conversion efficiency.

[0102] Therefore, the perovskite cell using the perovskite crystal provided in the embodiment 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 the following.

[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 highly efficient 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 stacked cells. However, lead-tin perovskite cells have a more 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 property in redox reaction and is easily oxidized to Sn 4+ , and Sn 4+ The electronic structure is unstable and easily forms electron-hole pairs, which increases the difficulty of carrier transport 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 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, so that the surfaces of the perovskite grains, the perovskite crystals, and the perovskite layer are all stable Pb 2+ , thereby reducing or even avoiding Sn in the perovskite layer 2+ Oxidized to Sn 4+ , which can improve the stability of the battery device and also make the battery device 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. Optionally, 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 include CH3NH3 + (abbreviated as MA + )、CH3CH2NH3 + 、CH(NH2)2 + (abbreviated as FA + )、Li + 、Na + , K + , Rb + , Cs + Optionally, A in ABX3, A2CDX6 and APbX3 may independently include CH3NH3 + 、CH3CH2NH3 + 、CH(NH2)2 + , Cs + One or more of .

[0111] The A in ABX3, A2CDX6 and APbX3 may be the same or different, and this is not limited in the embodiments of the present application.

[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 may independently include Cl - Br - ,I -One or more of .

[0113] X in ABX3, A2CDX6 and APbX3 may 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 also 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-dimethylethyleneboric acid, n-butylamine, glutaronitrile, 4-chlorobenzyl mercaptan, hydrocinnamic acid, and ethylsulfonic acid.

[0118] In some embodiments, a ratio of a thickness of a passivation layer of a perovskite grain to a grain size of the perovskite grain 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, 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-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. Optionally, the thickness of the passivation layer of the perovskite grains may be 10 nm-94 nm, 12 nm-71 nm, 15 nm-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 300nm-1000nm. For example, the grain size of the perovskite crystals can be 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, or a range consisting of any of the above values.

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

[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, and three areas are randomly selected on the top view of the perovskite layer (ensuring that the number of perovskite grains in each area is greater than or equal to 80), and 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 taken as the grain size of each perovskite grain.

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

[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, 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 also 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, and the first threshold value represents the maximum value of the ionic radius of the cation of the precursor compound 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 mixed precursor solution, due to the large molecular size of the third component, it cannot be located at 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+ The perovskite crystals are separated from the grain boundaries and surfaces to form core-shell structured perovskite grains, and the passivation layer of the perovskite grains formed integrally can play a role in passivating both 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 the third component can be reduced 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 a 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 together form the first perovskite component in the core, whereby, during the crystallization process, a portion of the second precursor solution forms the second perovskite component in the passivation layer, and 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 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 make adjustments according to 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 perovskite grains formed by crystallization 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 improve the stability of the perovskite battery and 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 perovskite grains formed by crystallization 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 be complexed with the metal cations in the first perovskite component, which is not conducive to the formation of perovskite grains with a core-shell structure, and is not conducive to improving the stability of the battery device. In addition, too much third component will also accumulate (or stack) on the surface and grain boundary position of the perovskite crystal, thereby increasing the interface resistance of the perovskite layer, affecting the transmission 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 a perovskite layer on the substrate to form a thin film; and removing the solvent in the thin film to form the perovskite layer.

[0147] The precursor solution for forming the 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 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, 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 precursor compounds in the first precursor solution and the second precursor solution.

[0148] The perovskite layer includes a perovskite crystal, the perovskite crystal 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, and the passivation layer is formed integrally with 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 boundary 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 value of the 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 large molecular size of the third component, it cannot be located at the cation position of the perovskite crystal, so these third components will exist as impurities. During the crystallization process, the third components will be squeezed to the grain boundaries and surfaces of the perovskite crystals. And these third components contain 2+ Coordination or complexing groups, thus, during the grain growth process, the third component will drive Pb 2+ The perovskite crystals are separated from the grain boundaries and surfaces to form core-shell structured perovskite grains, and the passivation layer of the perovskite grains formed integrally can play a role in passivating both 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 the third component can be reduced 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 embodiment 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 a 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 together form the first perovskite component in the core, whereby, during the crystallization process, a portion of the second precursor solution forms the second perovskite component in the passivation layer, and 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 make adjustments 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 perovskite grains formed by crystallization 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 improve the stability of the perovskite battery and 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 perovskite grains formed by crystallization 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 be complexed with the metal cations in the first perovskite component, which is not conducive to the formation of perovskite grains with a core-shell structure, and is not conducive to improving the stability of the battery device. In addition, too much third component will also accumulate (or stack) on the surface and grain boundary position of the perovskite crystal, thereby increasing the interface resistance of the perovskite layer, affecting the transmission 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-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, the embodiments of the present application also provide a perovskite battery.

[0166] Figure 2 It is a schematic diagram of the structure of the perovskite battery provided in some embodiments of the present application.

[0167] like Figure 2 As shown, 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 specifically limited and can be selected according to actual needs. In some embodiments, the thickness of the perovskite layer 3 can be 400nm-1000nm.

[0170] The perovskite cell provided in the embodiment 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 inverse 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 specifically 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 C61 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, the bottom energy level of its conduction band can better match the bottom energy level of the conduction band of the perovskite layer, which is conducive to promoting the transmission of electrons.

[0175] The thickness of the electron transport layer is not specifically 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 specifically 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-anilino)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 specifically 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 may 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 specifically 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 may 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 specifically 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 embodiment 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 comprises 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 a 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] The precursor solution for forming the 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 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, 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 precursor compounds in the first precursor solution and the second precursor solution.

[0189] The perovskite layer of the perovskite cell includes a perovskite crystal, the perovskite crystal includes one or more perovskite grains, the perovskite grains include a core and a passivation layer located on at least part of the surface of the core, and the passivation layer is formed integrally with 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 boundary 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 value of the 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 large molecular size of the third component, it cannot be located at the cation position of the perovskite crystal, so these third components will exist as impurities. During the crystallization process, the third components will be squeezed to the grain boundaries and surfaces of the perovskite crystals. And these third components contain 2+ Coordination or complexing groups, thus, during the grain growth process, the third component will drive Pb 2+ The perovskite crystals are separated from the grain boundaries and surfaces to form core-shell structured perovskite grains, and the passivation layer of the perovskite grains formed integrally can play a role in passivating both 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 the third component can be reduced 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 a 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 together form the first perovskite component in the core, whereby, during the crystallization process, a portion of the second precursor solution forms the second perovskite component in the passivation layer, and 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 make adjustments 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 perovskite grains formed by crystallization 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 improve the stability of the perovskite battery and 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 perovskite grains formed by crystallization 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 be complexed with the metal cations in the first perovskite component, which is not conducive to the formation of perovskite grains with a core-shell structure, and is not conducive to improving the stability of the battery device. In addition, too much third component will also accumulate (or stack) on the surface and grain boundary position of the perovskite crystal, thereby increasing the interface resistance of the perovskite layer, affecting the transmission 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-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 also be reduced.

[0205] The film forming methods of the first electrode 1, the first charge transport layer 2, the second charge transport layer 4, and the second electrode 5 are not specifically limited, and film forming methods 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 scraping, mechanical pressing, sol-gel method, pulsed laser deposition, etc.

[0206] [Perovskite layer]

[0207] In a seventh aspect, the embodiments of the present application further provide another perovskite layer (referred to as perovskite layer II for distinction), which can be used in perovskite cells. The following is an explanation with reference to the accompanying drawings.

[0208] The perovskite layer includes a middle part and a passivation part located on at least part of the surface of the middle part, the middle part includes perovskite crystals, and 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 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.

[0209] By providing the passivation material on the upper surface and / or the lower surface of the middle part along the thickness direction and the peripheral surface of the middle part, the defect state density of the perovskite layer can be reduced, the non-radiative recombination and impurity scattering can be reduced, 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 have a high photoelectric conversion efficiency.

[0210] Figure 3 and Figure 4 Schematic diagram 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] like Figure 3 As shown, in some embodiments, the passivation portion 33 may include a first passivation portion 331 located on both the upper surface and the lower surface of the middle portion 32 and a second passivation portion 332 located on the outer circumference of the middle portion 32 .

[0212] like Figure 4As shown, 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 some 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 peripheral surface 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 close to the light incident side along the thickness direction.

[0215] In some embodiments, a surface (ie, the upper surface) of the middle portion away from the light incident side in the thickness direction and the outer peripheral surface of the middle portion are both provided with passivation materials, 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, 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, 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-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 of homopolymers and copolymers of at least one monomer of vinyl chloride, thiophene and its derivatives, carbazole and its derivatives, and styrene sulfonic acid. For example, the polymer may include one or more of polyvinyl chloride, polythiophene, polycarbazole, poly(3,4-ethylenedioxythiophene), and poly(styrene sulfonic acid). This may allow 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 2,000.

[0224] Organic small molecules include halogen atoms and / or heteroatoms, which 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 usually larger than the maximum value of the ionic radius of cations in perovskite crystals, so it is not easy to enter the lattice of perovskite crystals. Therefore, when crystallizing to form a perovskite layer, organic small molecules can exist as impurities and can be separated from the grain boundaries and surfaces of perovskite crystals, playing a role in passivating grain boundary defects and surface defects.

[0225] In some embodiments, the organic small molecule may include one or more of alkylamines and their derivatives, aromatic amines and their derivatives, nitrogen heterocyclic compounds and their derivatives, thiophene and its derivatives, carbazole and its derivatives, pentafluoroiodobenzene and its derivatives. The derivative of a compound generally refers to a substance after an atom or a group of atoms in the compound is replaced by another atom or a group of atoms. As an example, the organic small molecule may include one or more of phenethyl iodinated amine, 2-(4-fluorophenyl)ethylamine hydroiodide, isobutylamine, 1-aminopentane, trimethylammonium bromide, tetramethylphosphonic acid carbazole, vinyl carbazole, 3,4-ethylenedioxythiophene, and styrene sulfonate. 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 embodiments of the present application.

[0227] [Perovskite battery]

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

[0229] like Figure 3 and Figure 4As shown, 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 middle portion 32. This is beneficial to promote the transport of carriers and improve 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 middle portion 32. This is beneficial to promote the transport of carriers and improve 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, 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, and the LUMO energy level of the first passivation portion 331 is lower than the CBM energy level of the middle portion 32. This is beneficial to promote the transmission of carriers and improve 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, 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, and the HUMO energy level of the first passivation portion 331 is greater than the VBM energy level of the middle portion 32. This is beneficial to promote the transmission of carriers and improve 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 comprises 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 crystals) 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, 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 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, and the second precursor solution includes a second solvent and a The A-position precursor compound AX, PbX2 and a third component, the third component includes at least one substituted alkyl 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; 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 method further includes applying a passivation material provided in an embodiment 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 forming 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 forming 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 scraping, mechanical pressing, sol-gel method, pulsed laser deposition, etc.

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

[0248] [Photovoltaic modules]

[0249] The embodiments of the present application also provide a photovoltaic module, which includes the perovskite cell provided in the embodiments of the present application or the perovskite cell prepared by the method provided in the embodiments of the present application. The perovskite cell can be used as a power source for the photovoltaic module after processes such as series-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 a device used in the fields of communication, transportation, industry and agriculture, lighting, etc. As an example, the power-consuming device may include satellites, communication equipment, traffic lights, lighthouses, wireless telephone booths, monitoring equipment in the field of oil drilling, power supply systems, camping lights, electric vehicles, chargers for electronic devices, etc.

[0254] Example

[0255] The following examples more specifically describe the disclosure of the present application, which are intended for illustrative purposes only, as it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the disclosure of the present application. Unless otherwise stated, 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 can be used directly without further processing, and the instruments used in the examples are commercially available.

[0256] Example 1-1

[0257] Preparation of the first electrode

[0258] Take 2.0cm×2.0cm FTO conductive glass, remove 0.35cm of FTO at both ends by laser etching to expose the glass substrate; ultrasonically clean the laser-etched FTO conductive glass several times with water, acetone, and isopropanol in turn; blow dry the solvent of the cleaned FTO conductive glass under a nitrogen gun, and then put it into 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, then placed on a heating table, annealed at 150°C for 10 minutes, cooled to room temperature (25°C) to obtain a hole transport layer, and then placed in an ultra-purified glove box filled with nitrogen.

[0261] Preparation of perovskite layer

[0262] 335 mg 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 PbI2 and 85 mg of methylamine iodide (MAI) were dissolved in a mixed solvent consisting of dimethylphosphonic acid, DMF and DMSO to obtain a methylamine lead iodide (MAPbI3) precursor solution, and 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 precursor solution and the MAPbI3 precursor solution were mixed by stirring to obtain a precursor solution.

[0263] The precursor solution is spin-coated on the hole transport layer at a speed of 1000 rpm for 10 seconds and then at a speed of 4000 rpm for 40 seconds, and 400 μL of chlorobenzene is quickly added at the 30th second, followed by annealing at 100°C for 10 minutes and cooling to room temperature to obtain a 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 a tin-lead mixed perovskite material, and the perovskite component in the passivation layer is 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 s to obtain an electron transport layer, and then an 8-15 nm BCP passivation layer was evaporated.

[0266] Preparation of the second electrode

[0267] The sample obtained above was placed in a vapor deposition machine to vapor deposit an Ag electrode 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 shown 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 a different third component is used in the preparation of the methylamine lead iodine (MAPbI3) precursor solution. The type of the third component is 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 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 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 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, followed by annealing at 100° C. for 10 minutes and cooling 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, and 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, annealing was performed in a nitrogen environment at 100°C for 10 minutes 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 MA0.5 FA 0.5 Pb 0.5 Sn 0.5 I3, and then methylamine iodide in evaporation source 6 is heated at 140°C to evaporate and deposit onto MA 0.5 FA 0.5 Pb 0.5 Sn 0.5 After the deposition is completed, annealing is performed in a nitrogen environment at 100°C for 10 minutes to obtain a 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 reach the intensity of one sun, AM 1.5. During the test, the battery device is connected to the digital source meter, tested under light, and the IV curve is obtained. The short-circuit current Jsc (unit: mA / cm 2 ), open circuit voltage Voc (unit V), maximum light output current Jmpp (unit mA) and maximum light output voltage Vmpp (unit V). The fill factor FF of the perovskite cell is calculated by the formula FF = Jsc × Voc / (Jmpp × Vmpp), unit %. The photoelectric conversion efficiency PCE of the perovskite cell is calculated by the formula PCE = (Jsc × Voc × FF) / Pw, unit %; Pw represents the input power, unit mW.

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

[0283] Table 1

[0284]

[0285]

[0286] 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.

[0287] From the test results of Comparative Examples 1-2, it can be seen that by vapor deposition on the surface of the prepared tin-lead mixed perovskite grains to form a passivation layer, an interface is formed between the core and shell of the finally prepared perovskite grains. The existence of the interface affects the carrier transport, and the effect of improving the stability of the perovskite crystal is not obvious. Therefore, the stability and photoelectric conversion efficiency of the perovskite battery prepared in Comparative Examples 1-2 are both low.

[0288] Example 2-1

[0289] 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.

[0290] Preparation of perovskite layer

[0291] 335 mg 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 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, and 3 ml 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.

[0292] Spin coating on 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, followed by annealing at 100° C. for 10 minutes and cooling to room temperature to obtain a perovskite layer.

[0293] The perovskite layer includes a middle portion and a passivation portion, wherein the passivation portion includes a first passivation portion located on an upper surface and a lower surface of the middle portion along a thickness direction and a second passivation portion located on an outer peripheral surface of the middle portion.

[0294] Examples 2-2 to 2-5

[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, the amount of PbS colloidal quantum dot solution used is different, and the specific parameters are shown in Table 2.

[0296] Examples 2-6 to 2-10

[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, different passivation materials are used. The specific parameters are shown in Table 2.

[0298] Comparative Example 2-1

[0299] 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, and the specific parameters are shown in Table 2.

[0300] 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.

[0301] Table 2

[0302]

[0303] 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.

[0304] It can be seen from the test results of Comparative Example 2-1 that when the outer peripheral surface of the perovskite layer does not have a passivation material, the stability and photoelectric conversion efficiency of the prepared perovskite battery are relatively low.

[0305] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A perovskite crystal, characterized in that: The perovskite crystal includes one or more perovskite grains, and the perovskite grain includes a core portion and a passivation layer located on at least a portion of the surface of the core portion, and the passivation layer is formed integrally with the core portion. 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, characterized in that The perovskite crystal further includes a third component, the third component is located on the surface and / or grain boundary of the perovskite crystal, the third component includes an alkyl group substituted by 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; Optionally, 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.

3. The perovskite crystal according to any one of claims 1 to 2, characterized in that: 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 may be 0.02:1-0.14:1; and / or, The thickness of the passivation layer is 1 nm-100 nm, and can be optionally 15 nm-56 nm.

4. The perovskite crystal according to any one of claims 1 to 3, characterized in that 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.

5. The perovskite crystal according to any one of claims 1 to 4, characterized in that: 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, optionally, B includes Pb 2+ Sn 2+ One or two of, more optionally, B includes Sn 2+ Or include Pb 2+ and Sn 2+ .

6. The perovskite crystal according to any one of claims 1 to 5, characterized in that: A in ABX3, A2CDX6 and APbX3 independently comprises CH3NH3 + 、CH3CH2NH3 + 、CH(NH2)2 + , Li + 、Na + , K + , Rb + , Cs + One or more of, optionally, A in ABX3, A2CDX6 and APbX3 independently comprises CH3NH3 + 、CH3CH2NH3 + 、CH(NH2)2 + , Cs + One or more of; and / or, X in ABX3, A2CDX6 and APbX3 each independently represents a halogen ion. Optionally, X in ABX3, A2CDX6 and APbX3 each independently comprises F - , Cl - Br - ,I - More preferably, X in ABX3, A2CDX6 and APbX3 independently includes Cl - Br - ,I - One or more of; and / or, C represents a monovalent metal cation, and optionally, C includes Li + 、Na + , K + , Rb + , Cs + 、Ag + One or more of; and / or, D represents a trivalent metal cation, and optionally, D includes In 3+ 、Bi 3+ , Sb 3+ One or more of .

7. A precursor solution for preparing the perovskite crystal according to any one of claims 1 to 6, characterized in that: 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.

8. The precursor solution according to claim 7, characterized in that 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 can be optionally 0.01:1-0.05:1; and / or, The first solvent comprises dimethylformamide and dimethyl sulfoxide, and optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1; and / or, The second solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:

1.

9. A perovskite layer, characterized in that: The perovskite layer comprises the perovskite crystal according to any one of claims 1 to 6.

10. A method for preparing a perovskite layer, characterized in that: 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, and the passivation layer is formed integrally with 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, ABX 3. A in 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.

11. The method according to claim 10, characterized in that 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 can be optionally 0.01:1-0.05:1; and / or, The first solvent comprises dimethylformamide and dimethyl sulfoxide, and optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1; and / or, The second solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:

1.

12. The method according to any one of claims 10-11, characterized in that: The step of removing the solvent in the thin film to form a perovskite layer comprises the following steps: transferring the substrate formed with the thin film to a hot stage for annealing to form a perovskite layer, Optionally, the annealing temperature is 80° C.-210° C.; and / or, Optionally, the annealing time is 1 min-30 min.

13. 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, It is characterized in that The perovskite layer includes the perovskite layer according to claim 8 and the perovskite layer prepared by the method according to any one of claims 10-12.

14. A method for preparing a perovskite battery, characterized in that: 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; 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, and the passivation layer is formed integrally with 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, ABX 3. A in 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.

15. The method according to claim 14, characterized in that 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 can be optionally 0.01:1-0.05:1; and / or, The first solvent comprises dimethylformamide and dimethyl sulfoxide, and optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:1; and / or, The second solvent includes dimethylformamide and dimethyl sulfoxide. Optionally, the volume ratio of dimethylformamide to dimethyl sulfoxide is 2:1-9:

1.

16. The method according to any one of claims 14-15, characterized in that: 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, Optionally, the annealing temperature is 80° C.-210° C.; and / or, Optionally, the annealing time is 1 min-30 min.

17. A perovskite layer, characterized in that: 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.

18. The perovskite layer according to claim 17, characterized in that The ratio of the thickness of the first passivation portion to the thickness of the middle portion is 1:5-1:20, and can be 1:6.5-1:15; 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 can be 1:6.5-1:15; and / or, The thickness of the middle portion is 400nm-1000nm.

19. The perovskite layer according to any one of claims 17 to 18, characterized in that 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 optionally includes one or more of polyvinyl chloride, polythiophene, polycarbazole, poly(3,4-ethylenedioxythiophene), and poly(styrene sulfonic acid); and / or, The organic small molecule includes 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, and optionally includes one or more of phenethylammonium iodide, 2-(4-fluorophenyl)ethylamine hydroiodide, isobutylamine, 1-aminopentane, trimethylammonium bromide, tetramethylphosphonic acid carbazole, vinyl carbazole, 3,4-ethylenedioxythiophene, and styrene sulfonate.

20. The perovskite layer according to any one of claims 17 to 19, characterized in that The perovskite crystal comprises the perovskite crystal according to any one of claims 1 to 6.

21. 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, It is characterized in that The perovskite layer comprises the perovskite layer according to any one of claims 17-20.

22. The perovskite cell according to claim 21, characterized in that 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.

23. The perovskite cell according to claim 21, characterized in that 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.

24. A method for preparing a perovskite battery according to any one of claims 21 to 23, characterized in that: 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.

25. The method according to claim 24, characterized in that Methods for forming a perovskite layer on the first charge transport layer include a solution method, a hydrothermal method, and a vapor deposition method.

26. The method according to claim 24 or 25, characterized in that 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, and can be optionally 0.01:1-0.1:

1.

27. The method according to claim 24, characterized in that 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; Applying a passivation material on the upper surface and the outer peripheral surface of the middle portion to complete the preparation of the perovskite layer; 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.

28. The method according to claim 27, characterized in that 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. Optionally, the method of applying the passivation material on the first charge transport layer includes vapor deposition.

29. A photovoltaic module, characterized in that: Including the perovskite battery according to claim 13, or the perovskite battery prepared by the method described in any one of claims 14-16, or the perovskite battery according to any one of claims 21-23, or the perovskite battery prepared by the method described in any one of claims 24-28.

30. An electrical device, characterized in that: It comprises one or more of the perovskite cell according to claim 13, the perovskite cell prepared by the method described in any one of claims 14-16, the perovskite cell according to any one of claims 21-23, the perovskite cell prepared by the method described in any one of claims 24-28, and the photovoltaic module according to claim 29, wherein the perovskite cell and the photovoltaic module are used to supply power to the electrical device.

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