Perovskite precursor solution, perovskite thin film and solar cell

Abstract

The invention belongs to the photovoltaic field, and particularly relates to a perovskite precursor solution, a perovskite thin film and a solar cell. A solvent of the perovskite precursor solution comprises a main solvent and an auxiliary solvent, the main solvent is N, N-diethyl formamide, the auxiliary solvent is selected from one or more of dimethyl propenyl urea, tetramethylurea, N, N-dimethylacetamide and N-methylacetamide, and the mass ratio of the main solvent to the auxiliary solvent is (1: 1)-(10: 1). The solvent of the perovskite precursor solution is green and low in toxicity, and controllable crystallization of the perovskite thin film can be realized by changing the perovskite nucleation and growth process so as to obtain the high-quality perovskite thin film. The use of a high-toxicity solvent is avoided, and the safety of the industrial environment is improved.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaics, and in particular relates to a perovskite precursor solution, a perovskite film and a solar cell. Background Art

[0002] Perovskite materials, due to their excellent optoelectronic properties, are used in a variety of fields, including solar cells, LEDs, and detectors. The band gap of perovskites can be adjusted to 1.60 to 1.70 eV, making them suitable for use in series or parallel stacking with silicon cells, thereby exceeding the Shockley limit and achieving higher photoelectric conversion efficiency. The photoelectric conversion efficiency of calcium-silicon two-terminal series stacked solar cells has exceeded 33%, making them the most promising next-generation photovoltaic cell.

[0003] However, solvents such as N,N-dimethylformamide (DMF) and anti-solvents such as toluene commonly used in the preparation of perovskites in the laboratory research stage are not suitable for industrial preparation due to their high toxicity. This is an important factor currently limiting its further development in industrialization and a challenge that needs to be urgently addressed.

[0004] The industrial preparation of perovskites must be carried out in a dry air environment, away from an inert gas atmosphere. Therefore, changes in key environmental factors have led to significant changes in the perovskite nucleation and crystallization process. The original classic mixed solvent system of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) is no longer applicable. The industrial preparation of perovskites in an air environment is more complex than the antisolvent method in an inert gas environment. The antisolvent-free method lacks the key steps of solvent extraction and pre-nucleation. One effective way to address this problem is to change the perovskite nucleation and growth process by changing the solvent to achieve controlled crystallization of the perovskite film and obtain high-quality perovskite films. Therefore, it is necessary to find more suitable mixed solvents to improve process compatibility and the photoelectric conversion efficiency of the battery. Summary of the Invention

[0005] The present invention addresses the above-mentioned problems existing in the prior art and proposes a perovskite precursor solution, a perovskite film, and a solar cell. The solvent of the perovskite precursor solution of the present invention includes a main solvent and a secondary solvent, the main solvent is N,N-diethylformamide (DEF), the secondary solvent is selected from one or more of dimethylpropylene urea (DMPU), tetramethyl urea (TMU), N,N-dimethylacetamide (DMAc), and N-methylacetamide (NMAc), and the mass ratio of the main solvent to the secondary solvent is 1:1-10:1. The solvent can change the arrangement of the lead iodine octahedron in the precursor solution, thereby changing the competitive behavior between the A-site cations and the solvent molecules during the nucleation process, thereby regulating crystallization and improving the crystal quality of the perovskite film, forming a good surface morphology and a larger grain size, thereby reducing residual solvent and residual impurities, forming a high-purity α-phase perovskite, and improving the light absorption performance of the film.

[0006] Specifically, the present invention provides a perovskite precursor solution, which includes a solvent and a perovskite structural material raw material, the solvent includes a main solvent and a secondary solvent, the main solvent is N,N-diethylformamide, and the secondary solvent is one or more selected from dimethylpropylene urea, tetramethyl urea, N,N-dimethylacetamide and N-methylacetamide, and the mass ratio of the main solvent to the secondary solvent is 1:1-10:1.

[0007] In one or more embodiments, the perovskite structure material raw material comprises A ions, B ions and X ions, wherein the A ions are monovalent cations, including one or more of cesium ions, rubidium ions, methylamine ions and formamidine ions; the B ions are divalent cations, including one or more of lead ions, copper ions, zinc ions, gallium ions, tin ions and calcium ions; the X ions are monovalent anions, including one or more of iodide ions, bromide ions, chloride ions, fluoride ions and thiocyanate ions; and the concentration of the B ions in the perovskite precursor solution is 1-3 mol / L.

[0008] The present invention also provides a method for preparing the perovskite film of the present invention, the method comprising coating the perovskite precursor solution described in any embodiment of the present invention, and then annealing to obtain the perovskite film.

[0009] In one or more embodiments, the method further comprises vacuum-treating the perovskite precursor solution after coating and before annealing.

[0010] In one or more embodiments, the coating method is selected from one or more of spin coating, blade coating, evaporation, printing, spray coating, spray pyrolysis and slot coating.

[0011] In one or more embodiments, the annealing temperature is 25-200°C;

[0012] In one or more embodiments, the annealing time is 1-60 min.

[0013] The present invention also provides a perovskite film prepared by the method described in any embodiment of the present invention.

[0014] In one or more embodiments, the perovskite film has a thickness of 10 nm to 100 μm.

[0015] In one or more embodiments, the perovskite film has a band gap of 0.9-3.0 eV.

[0016] In one or more embodiments, the perovskite film comprises a perovskite structure material having a chemical formula of ABX3.

[0017] The present invention also provides a solar cell, comprising the perovskite thin film described in any embodiment of the present invention.

[0018] In one or more embodiments, the solar cell is a stacked solar cell, which includes a first electrode, an electron transport layer, a first photoactive layer, a hole transport layer, an interface layer, a second photoactive layer, and a second electrode, wherein the first photoactive layer is a perovskite film, and the second photoactive layer is a crystalline silicon, perovskite, CdTe, CuIn x Ga (1-x) Se2 or GaAs, where 0<x<1.

[0019] In one or more embodiments, the first electrode includes one or more of tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, cerium-doped indium oxide, Au, Ag, Cu, Al, and Cr.

[0020] In one or more embodiments, the electron transport layer comprises C 60 、C 60 One or more of derivatives, tin oxide and titanium dioxide.

[0021] In one or more embodiments, the thickness of the electron transport layer is 5-200 nm.

[0022] In one or more embodiments, the hole transport layer includes [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, derivatives of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [2-(9H-carbazol-9-yl)butyl]phosphonic acid, derivatives of [2-(9H-carbazol-9-yl)butyl]phosphonic acid, 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, polyethylene terephthalate, polymers of 3-hexylthiophene, poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate, NiO X and CuSCN.

[0023] In one or more embodiments, the hole transport layer has a thickness of 5-100 nm.

[0024] In one or more embodiments, the interfacial layer includes one or more of tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, cerium-doped indium oxide, nanocrystalline silicon, and SnO 2 .

[0025] In one or more embodiments, the thickness of the interface layer is 5-100 nm.

[0026] In one or more embodiments, the second electrode includes one or more of tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, cerium-doped indium oxide, Au, Ag, Cu, Al, and Cr.

[0027] In one or more embodiments, the solar cell further includes a hole blocking layer located between the first electrode and the electron transport layer.

[0028] In one or more embodiments, the hole blocking layer is SnO2.

[0029] In one or more embodiments, the hole blocking layer has a thickness of 5-100 nm.

[0030] In one or more embodiments, the solar cell further includes an anti-reflection layer located on a surface of the first electrode.

[0031] In one or more embodiments, the antireflection layer is MgF2.

[0032] In one or more embodiments, the anti-reflection layer has a thickness of 10-500 nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the structure of a tandem solar cell in some embodiments of the present invention. DETAILED DESCRIPTION

[0034] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used herein. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0035] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0036] Herein, “comprising,” “including,” “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of,” for example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to have been disclosed herein.

[0037] Herein, all features such as values, amounts, amounts, and concentrations defined in numerical ranges or percentage ranges are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0038] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0039] Herein, the sum of the percentages of the various components of the composition is 100%.

[0040] Herein, when describing embodiments or examples, it should be understood that they are not intended to limit the present invention to these embodiments or examples. On the contrary, all substitutes, modifications and equivalents of the methods and materials described herein are encompassed within the scope of the present invention.

[0041] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0042] The present invention provides a perovskite precursor solution, which includes a solvent and a perovskite structural material raw material. The solvent includes a main solvent and a secondary solvent. The main solvent is DEF, and the secondary solvent is selected from one or more of DMPU, TMU, DMAc, and NMAc. In the solvent of the perovskite precursor solution, the mass ratio of the main solvent to the secondary solvent is 1:1-10:1.

[0043] The perovskite precursor solution of the present invention comprises a primary solvent of DEF and a secondary solvent selected from one or more of DMPU, TMU, DMAc, and NMAc. The primary solvent to secondary solvent ratio is 1:1 to 10:1, for example, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1. For example, the solvent of the perovskite precursor solution can be DEF and DMPU with a mass ratio of 1:1, DEF and DMPU with a mass ratio of 2:1, DEF and DMPU with a mass ratio of 4:1, DEF and DMPU with a mass ratio of 6:1, DEF and DMPU with a mass ratio of 8:1, DEF and DMPU with a mass ratio of 10:1, DEF and TMU with a mass ratio of 1:1, DEF and TMU with a mass ratio of 10:1, DEF and DMAc with a mass ratio of 1:1, DEF and DMAc with a mass ratio of 10:1, DEF and NMAc with a mass ratio of 1:1, and DEF and NMAc with a mass ratio of 10:1.

[0044] In the present invention, the perovskite structure material raw materials of the perovskite precursor solution include A ions, B ions and X ions, wherein the A ions are monovalent cations and can be selected from one or more of cesium ions, rubidium ions, methylamine ions, and formamidine ions; the B ions are divalent cations and can be selected from one or more of lead ions, copper ions, zinc ions, gallium ions, tin ions, and calcium ions; and the X ions are monovalent anions and can be selected from one or more of iodide ions, bromide ions, chloride ions, fluoride ions, and thiocyanate ions.

[0045] In the present invention, the concentration of B ions in the perovskite precursor solution can be 1-3 mol / L, for example, 1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, 2.0 mol / L, and 2.5 mol / L.

[0046] The method for preparing a perovskite film of the present invention comprises: coating the perovskite precursor solution of the present invention, and then annealing to obtain the perovskite film.

[0047] In the present invention, the coating method can be selected from one or more of spin coating, blade coating, evaporation, printing, spray coating, spray pyrolysis, and slit coating.

[0048] In the present invention, the annealing temperature may be 25-200°C, for example, 50°C, 75°C, 100°C, 125°C, or 150°C.

[0049] In the present invention, the annealing time may be 1-60 min, for example, 5 min, 10 min, 15 min, 20 min, or 30 min.

[0050] In the present invention, the thickness of the perovskite film can be 10nm-100μm, for example, 50nm, 100nm, 500nm, 1000nm, 2μm, 5μm, 10μm, 20μm, 50μm, 100μm; the band gap can be 0.9-3.0eV, for example, 0.9eV, 1.0eV, 1.1eV, 1.2eV, 1.3eV, 1.4eV, 1.5eV, 1.6eV, 1.7eV, 1.8eV, 1.9eV, 2.0eV, 2.1eV, 2.2eV, 2.3eV, 2.4eV, 2.5eV, 2.6eV, 2.7eV, 2.8eV, 2.9eV, 3.0eV.

[0051] The present invention provides a solar cell comprising the perovskite thin film described herein. The solar cell in the present invention may be a tandem solar cell. In the present invention, the tandem solar cell may sequentially comprise: a first electrode, an electron transport layer, a first photoactive layer, a hole transport layer, an interface layer, a second photoactive layer, and a second electrode.

[0052] In the present invention, the first electrode can be selected from one or more of tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), cerium-doped indium oxide (ICO), Au, Ag, Cu, Al and Cr.

[0053] In the present invention, the electron transport layer can be selected from C 60 、C 60 One or more of derivatives, tin oxide and titanium dioxide.

[0054] In the present invention, the thickness of the electron transport layer can be 5-200 nm, for example, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 120 nm, 140 nm, 160 nm, 180 nm, or 200 nm.

[0055] In the present invention, the first photoactive layer may be the perovskite film described in any embodiment of the present invention.

[0056] In the present invention, the hole transport layer can be selected from [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, derivatives of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [2-(9H-carbazol-9-yl)butyl]phosphonic acid, derivatives of [2-(9H-carbazol-9-yl)butyl]phosphonic acid, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, polyethylene terephthalate, polymers of 3-hexylthiophene, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, NiO X and CuSCN.

[0057] In the present invention, the thickness of the hole transport layer can be 5-100 nm, for example, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.

[0058] In the present invention, the interface layer can be selected from one or more of tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, cerium-doped indium oxide, nanocrystalline silicon and SnO2.

[0059] In the present invention, the thickness of the interface layer can be 5-100 nm, for example, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.

[0060] In the present invention, the second photoactive layer can be selected from crystalline silicon, perovskite, CdTe, CuIn x Ga (1-x) One or more of Se2 and GaAs, wherein 0<x<1.

[0061] In the present invention, the thickness of the second photoactive layer may be 50-500 nm, for example, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, or 450 nm.

[0062] In the present invention, the second electrode may be selected from one or more of tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, cerium-doped indium oxide, Au, Ag, Cu, Al and Cr.

[0063] In the present invention, the solar cell may further include a hole blocking layer between the first electrode and the electron transport layer. The hole blocking layer may be SnO2. The thickness of the hole blocking layer may be 5-100 nm, for example, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.

[0064] In the present invention, the solar cell may further include an antireflection layer located on the surface of the first electrode. The antireflection layer may be MgF2. The thickness of the antireflection layer may be 10-500 nm, for example, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 200 nm, 300 nm, or 400 nm.

[0065] The beneficial effects achieved by the present invention include:

[0066] This invention utilizes green solvents such as DEF and DMPU to replace the traditional toxic solvent DMF. This modifies the arrangement of lead-iodine octahedra in the precursor solution, thereby altering the competition between A-site cations and solvent molecules during the nucleation process. This achieves the goal of regulating crystallization and improving the crystal quality of the perovskite film. This results in a favorable surface morphology and larger grain size, while reducing residual solvent and impurities, forming high-purity α-phase perovskite and enhancing the film's light absorption properties. This invention provides a simple method for improving perovskite cells by controlling the crystallization process through solvents.

[0067] The present invention will be described below using specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents, and materials used in the examples and comparative examples are conventional methods, reagents, and materials in the art, unless otherwise stated. The starting compounds in the examples and comparative examples can all be purchased from commercial sources.

[0068] Example 1

[0069] In this embodiment 1, a stacked solar cell was prepared according to the following steps:

[0070] (1) N-type silicon wafer polishing, the velvet depth is 300nm;

[0071] (2) using PECVD to prepare front intrinsic amorphous silicon and n-type amorphous silicon with a total thickness of 25 nm;

[0072] (3) Back side intrinsic amorphous silicon, p-type amorphous silicon, with a total thickness of 20 nm;

[0073] (4) using sputtering to prepare a front transparent conductive oxide layer ITO with a thickness of 50 nm;

[0074] (5) Sputtering was used to prepare a back transparent conductive oxide layer ITO with a thickness of 130 nm;

[0075] (6) NiOx was prepared on the front side by magnetron sputtering with a thickness of 30 nm;

[0076] (7) Proportionally preparing a perovskite solution: uniformly mixing the raw materials of the perovskite structure (FAI, CsBr, PbI2, PbBr2) and an organic solvent to obtain a mixture, wherein the mass ratio of the main solvent DEF to the secondary solvent DMPU in the solvent is 1:1, to form a perovskite precursor solution. The molar concentration of FAI is 1.079 mol / L, the molar concentration of CsBr is 0.221 mol / L, the molar concentration of PbI2 is 1.079 mol / L, and the molar concentration of PbBr2 is 0.221 mol / L;

[0077] (8) The perovskite precursor solution was spin-coated at a speed of 4000 rpm, and then transferred to a vacuum chamber for 1 min, and then placed on a substrate for annealing at 100 °C for 20 min to form a perovskite light-absorbing layer with a thickness of 1 μm and a band gap of 1.66 eV;

[0078] (9) Place the substrate with the perovskite light absorbing layer in a vacuum coating apparatus. When the pressure in the chamber is less than 4×10 -6 Torr, started with At a rate of 30 nm, C was evaporated on the surface of the perovskite light absorbing layer. 60 , to form an electron transport layer;

[0079] (10) SnO2 was prepared by atomic layer deposition with a thickness of 20 nm;

[0080] (11) The ITO layer was prepared by sputtering with a thickness of 100 nm;

[0081] (12) Using thermal evaporation method to prepare Ag metal gate line layer with a thickness of 200nm;

[0082] (13) The MgF2 antireflection layer was prepared by thermal evaporation with a thickness of 100 nm.

[0083] Example 2

[0084] A stacked solar cell was prepared according to the method of Example 1, with the only difference being that in step 7, the solvent DEF:DMPU = 1:1 was changed to DEF:DMPU = 10:1.

[0085] Example 3

[0086] A stacked solar cell was prepared according to the method of Example 1, with the only difference being that in step 7, the solvent DEF:DMPU = 1:1 was changed to DEF:TMU = 1:1.

[0087] Example 4

[0088] A stacked solar cell was prepared according to the method of Example 1, except that in step 7, the solvent DEF:DMPU = 1:1 was changed to DEF:DMAc = 1:1.

[0089] Example 5

[0090] A stacked solar cell was prepared according to the method of Example 1, with the only difference being that in step 7, the solvent DEF:DMPU = 1:1 was changed to DEF:NMAc = 1:1.

[0091] Comparative Example 1

[0092] A stacked solar cell was prepared according to the method of Example 1, except that in step 7, the solvent DEF:DMPU = 1:1 was changed to DMF:DMSO = 3:1.

[0093] Comparative Example 2

[0094] A stacked solar cell was prepared according to the method of Example 1, with the only difference being that in step 7, the solvent DEF:DMPU = 1:1 was changed to DEF:DMPU = 1:10.

[0095] Test Case

[0096] Solar cell device performance test: Under standard test conditions (AM1.5, 25℃, 1000W / m2 ), the open circuit voltage, short circuit current density, fill factor and energy conversion efficiency of the stacked solar cells of Examples 1-5 and Comparative Examples 1-2 were obtained by using a steady-state test on an IV tester.

[0097] (1) Open circuit voltage (V oc ): The voltage value corresponding to the current being zero.

[0098] (2) Short-circuit current density (J sc ): The current value when the voltage is zero is the short-circuit current (I sc ), the current per unit battery surface area is the short-circuit current density.

[0099] (3) Fill Factor: The maximum output power of the battery (P max ) to the ratio of the product of open circuit voltage and short circuit current, the calculation formula is (P max / V oc *I sc ), where the maximum power point is the point where the battery output power reaches its maximum value.

[0100] (4) Photoelectric conversion efficiency (PCE): Energy conversion efficiency refers to the ratio of maximum output power to incident light power (Pin), and the calculation formula is (Pmax / Pin)*100%.

[0101] The test results of the open circuit voltage, short circuit current density, fill factor and photoelectric conversion efficiency of the stacked solar cells prepared in Examples 1-5 and Comparative Examples 1-2 are shown in Table 1.

[0102] Table 1: Open circuit voltage, short circuit current density, fill factor and energy conversion efficiency of the stacked solar cells prepared in Examples 1-5 and Comparative Examples 1-2

[0103]

[0104]

[0105] As can be seen from Table 1, the open circuit voltage, fill factor and energy conversion efficiency of the tandem solar cell of the embodiment prepared using the solvent of the present invention are significantly improved compared with the tandem solar cell of the comparative example.

Claims

1. A perovskite precursor solution, characterized in that The precursor solution includes a solvent and a perovskite structure material raw material, the solvent includes a main solvent and a secondary solvent, the main solvent is N,N-diethylformamide, the secondary solvent is one or more selected from dimethylpropylene urea, tetramethyl urea, N,N-dimethylacetamide and N-methylacetamide, and the mass ratio of the main solvent to the secondary solvent is 1:1-10:

1.

2. The perovskite precursor solution according to claim 1, wherein The perovskite structure material raw material comprises A ions, B ions and X ions; The A ion is a monovalent cation, including one or more of cesium ions, rubidium ions, methylamine ions and formamidine ions; the B ion is a divalent cation, including one or more of lead ions, copper ions, zinc ions, gallium ions, tin ions and calcium ions; the X ion is a monovalent anion, including one or more of iodide ions, bromide ions, chloride ions, fluoride ions and thiocyanate ions; the concentration of the B ions in the perovskite precursor solution is 1-3 mol / L.

3. A method for preparing a perovskite film, characterized in that: The method comprises coating the perovskite precursor solution according to claim 1 or 2, and then annealing to obtain a perovskite film.

4. The method according to claim 3, wherein The method has one or more of the following characteristics: The method further includes vacuum treating the perovskite precursor solution after coating and before annealing; The coating method is selected from one or more of spin coating, blade coating, evaporation, printing, spray coating, spray pyrolysis and slot coating; The annealing temperature is 25-200° C.; The annealing time is 1-60 min.

5. A perovskite film prepared by the method according to claim 3 or 4.

6. The perovskite film according to claim 5, wherein The perovskite film has a thickness of 10 nm to 100 μm; The perovskite film band gap is 0.9-3.0 eV; The perovskite film contains a perovskite structural material, and the chemical formula of the perovskite structural material is ABX3.

7. A solar cell, characterized in that: The solar cell comprises the perovskite thin film according to claim 5 or 6.

8. The solar cell according to claim 7, wherein The solar cell is a stacked solar cell, which includes a first electrode, an electron transport layer, a first photoactive layer, a hole transport layer, an interface layer, a second photoactive layer and a second electrode. The first photoactive layer is a perovskite film, and the second photoactive layer is a crystalline silicon, perovskite, CdTe, CuIn x Ga (1-x) Se2 or GaAs, where 0<x<1.

9. The solar cell according to claim 8, wherein The solar cell has one or more of the following features: The first electrode comprises one or more of tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, cerium-doped indium oxide, Au, Ag, Cu, Al, and Cr; The electron transport layer includes C 60 、C 60 one or more of derivatives, tin oxide and titanium dioxide; The thickness of the electron transport layer is 5-200 nm; The hole transport layer includes [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, derivatives of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, [2-(9H-carbazol-9-yl)butyl]phosphonic acid, derivatives of [2-(9H-carbazol-9-yl)butyl]phosphonic acid, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, polyethylene terephthalate, polymers of 3-hexylthiophene, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, NiO X and one or more of CuSCN; The thickness of the hole transport layer is 5-100 nm; The interface layer comprises one or more of tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, cerium-doped indium oxide, nanocrystalline silicon and SnO2; The thickness of the interface layer is 5-100 nm; The second electrode includes one or more of tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, cerium-doped indium oxide, Au, Ag, Cu, Al, and Cr.

10. The solar cell according to claim 8, wherein The solar cell further comprises a hole blocking layer between the first electrode and the electron transport layer, wherein the hole blocking layer is SnO2 and has a thickness of 5-100 nm; and / or The solar cell further includes an anti-reflection layer located on the surface of the first electrode. The anti-reflection layer is made of MgF2 and has a thickness of 10-500 nm.

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