Perovskite ink composition, perovskite ink and preparation method thereof, perovskite thin film and preparation method and application thereof

Abstract

The invention provides a perovskite ink composition, perovskite ink and a preparation method thereof, a perovskite thin film and a preparation method and application thereof. The perovskite ink composition comprises AX, BX2, a solvent and a passivator, A represents a monovalent cation, B represents a divalent cation, and X represents a halide ion; the solvents comprise at least two organic solvents with different boiling points, and the solvents comprise at least two organic solvents with different solubility to the passivating agent. The perovskite ink formed by the perovskite ink composition can be applied to preparation of a perovskite thin film with high crystallization and low defect state density, can be used by adopting blade coating, ink-jet printing, slit coating, roll-to-roll printing and the like, and can effectively improve the production efficiency and reduce the production cost especially in the preparation process of a large-area perovskite battery. The technological process is simplified and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite solar cells, and in particular to a perovskite ink composition, a perovskite ink and a preparation method thereof, a perovskite film and a preparation method and application thereof. Background Art

[0002] In recent years, perovskite has attracted extensive research in the field of thin-film optoelectronic materials and devices due to its advantages such as ultra-long carrier transmission distance, high defect tolerance, and solution processing. High-efficiency perovskite devices are inseparable from surface defect passivation, and small area (<0.1cm 2 ) The efficiency of perovskite solar cells has exceeded 25%, which is comparable to traditional crystalline silicon cells. There are still some problems in the preparation of large-area perovskite solar cells that cannot be ignored. It is difficult to control the nucleation and crystallization of perovskite films prepared by technologies such as scraping, inkjet printing, slit coating or roll-to-roll printing, which leads to low-quality perovskite films with high defect density. At present, in the high-efficiency large-area perovskite component process, the passivation technology still adopts the preparation method of film post-processing, which will limit the further large-scale development of perovskite cells on the one hand, and increase the process of industrial production and increase the cost on the other hand.

[0003] Based on the above situation, designing a simple and effective passivation method suitable for the preparation of large-area perovskite films and reducing their defect density is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The main purpose of the present invention is to provide a perovskite ink composition, a perovskite ink and a preparation method thereof, a perovskite film and a preparation method and application thereof, so as to solve the problems in the prior art that the defect density of the perovskite film is high or the preparation process is difficult to implement.

[0005] In order to achieve the above-mentioned object, according to one aspect of the present invention, a perovskite ink composition is provided, which comprises: AX, BX2, a solvent and a passivator, wherein A represents a monovalent cation, B represents a divalent cation, and X represents a halogen ion; the solvent comprises at least two organic solvents with different boiling points, and the solvent comprises at least two organic solvents with different solubility in the passivator.

[0006] Furthermore, the boiling point difference between the organic solvent with the highest boiling point and the organic solvent with the lowest boiling point among the solvents is 20 to 150°C;

[0007] Preferably, the solvent includes at least two of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, γ-butyrolactone, 2-methoxyethanol, acetonitrile, ethanol, methanol, isopropanol, chlorobenzene, and ethyl acetate.

[0008] Further, the passivating agent includes any one or more of cesium acetate, cesium chloride, cesium iodide, cesium bromide, rubidium iodide, potassium chloride, 6TIC-4F, theophylline, caffeine, theobromine, 1-aminopyrene and phenylethylamine halide;

[0009] Preferably, the molar ratio of the passivator to AX is 1:1000 to 1:10;

[0010] Preferably, the concentration of the passivating agent in the solvent is 0.1 to 10 mol%.

[0011] Further, the passivating agent includes any one or more of cesium acetate, cesium chloride, cesium iodide, cesium bromide, rubidium iodide, and potassium chloride, and the solvent includes at least one of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, and γ-butyrolactone;

[0012] And / or, the passivating agent includes any one or more of 6TIC-4F, theophylline, caffeine, theobromine and 1-aminopyrene, and the solvent includes at least one of 2-methoxyethanol, acetonitrile, ethanol, methanol, isopropanol, chlorobenzene and ethyl acetate.

[0013] Furthermore, AX and BX2 can form ABX3 or A2(ABX3) n-1 BX4 structure; preferably, the mixture formed by the composition is a homogeneous solution.

[0014] According to another aspect of the present application, a perovskite ink is provided, wherein the perovskite ink is prepared from any one of the above-mentioned compositions.

[0015] According to another aspect of the present application, a method for preparing a perovskite film is provided. The preparation method comprises: placing the above-mentioned perovskite ink on a substrate, and evaporating the solvent to obtain the perovskite film.

[0016] Further, the method of disposing the perovskite ink includes any one of blade coating, inkjet printing, slit coating and roll-to-roll printing.

[0017] Preferably, the method of evaporating the solvent comprises any one of heating, gas extraction and laser-assisted annealing;

[0018] Optionally, when the solvent is evaporated by heating, the heating temperature is 80 to 200°C.

[0019] According to another aspect of the present application, a perovskite film is provided, and the perovskite film is prepared by any one of the above preparation methods.

[0020] According to a fifth aspect of the present application, a photovoltaic device is provided, wherein the photovoltaic component contains the above-mentioned perovskite film.

[0021] By applying the technical solution of the present invention, the perovskite ink composition contains a perovskite precursor, a solvent and a passivator at the same time. Since the solvent is a mixed solvent with different boiling points and the solubility of the same passivator is different, the volatility of the solvent can be brought into play when it is used in the process of preparing the perovskite film. The passivator is integrated into the perovskite ink by utilizing the crystallization sequence from top to bottom in the preparation process. The perovskite ink formed by the perovskite ink composition can be applied to the preparation of perovskite films with high crystallinity and low defect state density, and can be used by scraping, inkjet printing, slit coating, roll-to-roll printing and the like. Especially in the preparation process of large-area perovskite batteries, it can effectively improve production efficiency, simplify the process flow and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 A physical picture of a perovskite film according to Example 1 of the present invention is shown;

[0024] Figure 2 PL spectra of the upper and lower surfaces of the perovskite film according to Example 1 and Comparative Example 1 of the present invention are shown;

[0025] Figure 3 PL spectra of the upper and lower surfaces of the perovskite film according to Example 2 of the present invention and Comparative Example 1 are shown;

[0026] Figure 4 PL spectra of the upper and lower surfaces of the perovskite thin film according to Example 3 of the present invention and Comparative Example 1 are shown;

[0027] Figure 5 PL spectra of the upper and lower surfaces of the perovskite films according to Example 4 of the present invention and Comparative Example 2 are shown. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0029] As analyzed in the background technology of this application, there are problems in the prior art such as high defect density of perovskite films or difficulty in implementing the preparation process. In order to solve this problem, this application provides a perovskite ink composition, perovskite ink and preparation method thereof, perovskite film and preparation method and application thereof.

[0030] According to a typical embodiment of the present application, a perovskite ink composition is provided, which comprises: AX, BX2, a solvent and a passivator, wherein A represents a monovalent cation, B represents a divalent cation, and X represents a halogen ion; the solvent comprises at least two organic solvents with different boiling points, and the solvent comprises at least two organic solvents with different solubility in the passivator.

[0031] The perovskite ink composition of the present application contains a perovskite precursor, a solvent and a passivator at the same time. Since the solvent contained is a mixed solvent with different boiling points and the solubility of the same passivator is different, the volatility of the solvent can be brought into play when it is used in the process of preparing the perovskite film. The passivator is integrated into the perovskite ink by utilizing the crystallization sequence from top to bottom in the preparation process. The perovskite ink formed by the perovskite ink composition can be applied to the preparation of perovskite films with high crystallinity and low defect state density, and can be used by scraping, inkjet printing, slit coating, roll-to-roll printing and the like. Especially in the preparation process of large-area perovskite batteries, it can effectively improve production efficiency, simplify the process flow and reduce production costs.

[0032] The solvent in the above composition can be selected from the prior art, with different boiling points and different solubility in the passivator in the composition, and it can have good solubility with other components in the composition. In some preferred embodiments of the present application, the boiling point of the organic solvent with the highest boiling point in the solvent differs from that of the organic solvent with the lowest boiling point by 20 to 150°C, and the integrated passivation effect of the top and bottom interfaces of the formed perovskite film is better. Exemplarily, the boiling point of the organic solvent with the highest boiling point in the solvent differs from that of the organic solvent with the lowest boiling point by 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C or any range between the two.

[0033] In order to realize the volatilization order of different solvents in the composition, make its gradient volatilization, and passivator reaches the specified surface or forms concentration gradient during volatilization, the single passivator in the composition is only dissolved in one of the solvents, or has a larger solubility difference in two solvents. In some embodiments of the present application, the solubility of a single passivator in at least two organic solvents in the composition differs by 5 times or more, such as 6 times, 7 times, 8 times, 9 times, 10 times, 11 times, 13 times, 15 times, 18 times, 20 times, 25 times, 30 times, 40 times, 50 times or any range between the two. The researchers of the present application found that when the solubility of a single passivator in at least two organic solvents in the composition differs by 5 times or more, the greater the solubility difference, the more obvious the effect of directional passivation, the smaller the difference, the easier it is to form a mixed gradient distribution.

[0034] Preferably, the solvent includes at least two of dimethylformamide (DMF), dimethylacetamide, dimethyl sulfoxide (DMSO), N-methylpyrrolidone, γ-butyrolactone, 2-methoxyethanol (2-ME), acetonitrile (ACN), ethanol, methanol, isopropanol (IPA), chlorobenzene, and ethyl acetate. The above solvents have good solubility for perovskite raw materials, and it is easy to select at least two solvents with different solubility for a single passivator.

[0035] The above-mentioned passivator can be selected from the prior art without special requirements, including but not limited to any one or more of cesium acetate, cesium chloride, cesium iodide, cesium bromide, rubidium iodide, potassium chloride, 6TIC-4F, theophylline, caffeine, theobromine, 1-aminopyrene and phenylethylamine halide. In order to further improve the passivation effect of the perovskite film formed by the composition and improve the comprehensive performance, in some embodiments of the present application, the molar ratio of the passivator to AX is 1:1000 to 1:10, preferably 1:1000 to 1:100. In some embodiments of the present application, the concentration of the passivator in the solvent is 0.1 to 10 mol%, preferably, the concentration of the passivator in the solvent is 0.1 to 10 mol%, which has a more obvious effect on improving the defect density of the perovskite film.

[0036] According to the principle of like dissolves like, strongly polar molecules are easily dissolved in strongly polar solvents, and weakly polar molecules are easily dissolved in weakly polar solvents. Often, based on the specific type of the passivator, a solvent with better solubility is selected, and one or more solvents with different boiling points and large solubility differences are used in combination, so as to achieve a low-boiling point solvent that evaporates first, and the passivator in it reaches the surface, and a high-boiling point solvent that evaporates later, and the passivator in it reaches the bottom.

[0037] In some typical embodiments of the present application, the passivator includes any one or more of cesium acetate, cesium chloride, cesium iodide, cesium bromide, rubidium iodide, and potassium chloride, and the solvent includes at least one of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone and γ-butyrolactone. These solvents not only have good solubility for AX and BX2, but also have good solubility for the above-mentioned passivators. Organic solvents that are insoluble or have poor solubility in the above-mentioned passivators such as cesium acetate can be selected for use in combination.

[0038] In some typical embodiments of the present application, the passivator includes any one or more of 6TIC-4F, theophylline, caffeine, theobromine and 1-aminopyrene, and the solvent includes at least one of 2-methoxyethanol, acetonitrile, ethanol, methanol, isopropanol, chlorobenzene and ethyl acetate. These solvents have good solubility for AX and BX2, and have slightly weak polarity and are easy to dissolve the above-mentioned passivators. Selecting one or more solvents therefrom can achieve a better passivation effect.

[0039] The composition of the present application has no limitation on the final perovskite formed. For example, it can be lead-based perovskite, lead-free perovskite and double perovskite. The perovskite structure includes three-dimensional ABX3 and all two-dimensional perovskites. The precursors AX and BX2 forming these perovskite structures in the composition can be selected from the prior art without special requirements. Those skilled in the art can select the corresponding perovskite precursor according to specific needs, and will not be introduced one by one here.

[0040] Preferably, the mixture formed by the composition is a homogeneous solution.

[0041] According to another typical embodiment of the present application, a perovskite ink is provided, and the perovskite ink is prepared by any of the above-mentioned compositions. The perovskite ink is a mixed solvent with different boiling points, and the volatile characteristics of the solvent can be exerted in the process of applying it to the preparation of the perovskite film. The passivator is fused in the perovskite ink by using the crystallization order from top to bottom in the preparation process, and the integrated passivation of the top and bottom interfaces is realized with the perovskite crystallization process, avoiding the possibility of poor wettability after conventional bottom passivation, and enhancing the force of the passivation molecule on the perovskite surface. The perovskite ink formed by the perovskite ink composition can be applied to the preparation of perovskite films with high crystallization and low defect state density, and can be used in the manner of scraping, inkjet printing, slit coating, roll-to-roll printing, etc., especially for the preparation process of large-area perovskite batteries, it is possible to effectively improve production efficiency, simplify process flow, and reduce production costs.

[0042] A person skilled in the art can easily prepare the above perovskite ink composition into perovskite ink according to the prior art method. As an example, the method for preparing perovskite ink from the above perovskite ink composition is as follows: after mixing AX, BX2, solvent and passivating agent in the composition, stirring continuously for 1 to 24 hours, the perovskite ink is obtained.

[0043] According to another typical embodiment of the present application, a method for preparing a perovskite film is provided. The method comprises placing the above-mentioned perovskite ink on a substrate, and evaporating the solvent to obtain the perovskite film.

[0044] The preparation method utilizes the mixed solvent with different boiling points of the above-mentioned perovskite ink, which can give play to the volatile characteristics of the solvent in the process of preparing the perovskite film. In the process of preparing the perovskite film, the crystallization sequence from top to bottom is used to fuse the passivator into the perovskite ink, and the integrated passivation of the top and bottom interfaces is realized with the perovskite crystallization process. Since the bottom passivation and the perovskite are prepared as a whole, the possibility of poor wettability after conventional bottom passivation is avoided; since the top passivation and the perovskite are prepared as a whole, the force of the passivation molecule on the perovskite surface is enhanced. The preparation method can be applied to the preparation of high-crystallization and gradient-doped perovskite films, and can be used by scraping, inkjet printing, slit coating, roll-to-roll printing, etc., especially in the preparation process of large-area perovskite cells, it can effectively improve production efficiency, simplify the process flow, and reduce production costs.

[0045] In some embodiments of the present application, the method of setting the perovskite ink includes any one of blade coating, inkjet printing, slit coating and roll-to-roll printing, which is convenient for improving the production efficiency of the perovskite film, especially for the preparation process of large-area perovskite batteries, the effect is better, not only effectively reducing the defect density, but also simplifying the process flow and significantly reducing production costs.

[0046] The method of evaporating the solvent can be selected from the prior art, including but not limited to any one of heating, gas extraction and laser-assisted annealing. In some embodiments of the present application, when the solvent is evaporated by heating, the heating temperature is 80-200° C., the volatilization efficiency is high, and the passivation effect is good, which is conducive to further improving the comprehensive performance of the prepared perovskite film.

[0047] According to another embodiment of the present application, a perovskite film is provided, and the perovskite film is prepared by any of the above-mentioned preparation methods. The perovskite film utilizes the above-mentioned perovskite ink having a mixed solvent with different boiling points, and can give play to the characteristics of the volatile characteristics of the solvent in the process of preparing the perovskite film. In the process of preparing the perovskite film, the crystallization sequence from top to bottom is used to fuse the passivator into the perovskite ink, and the integrated passivation of the top and bottom interfaces is realized with the perovskite crystallization process. Since the bottom passivation and the perovskite are prepared as a whole, the possibility of poor wettability after the bottom passivation is avoided; since the top passivation and the perovskite are prepared as a whole, the force of the passivation molecule on the perovskite surface is enhanced. The above-mentioned perovskite film can be prepared by a variety of methods, and is particularly suitable for the production and preparation of large-area perovskite batteries.

[0048] According to another embodiment of the present application, a photovoltaic device is provided, wherein the photovoltaic device contains the above-mentioned perovskite film.

[0049] The photovoltaic device of the present application adopts the above-mentioned perovskite film. Since the top and bottom interfaces are integrated and passivated during the perovskite crystallization process, the possibility of poor wettability after bottom passivation is avoided, the force of the passivation molecules on the perovskite surface is enhanced, the defect density is low, and the performance of the photovoltaic device can be significantly improved. Moreover, the above-mentioned perovskite film preparation process is simple, which can significantly reduce the production cost of photovoltaic devices, especially suitable for the production and preparation of large-area perovskite photovoltaic devices.

[0050] The above photovoltaic device includes a nip structure and a pin structure. The specific composition and preparation method can refer to the prior art and will not be described in detail here.

[0051] The beneficial effects that can be achieved by the present application will be further illustrated below in combination with embodiments and comparative examples.

[0052] Example 1

[0053] At room temperature, 0.8 mmol of iodomethane (FAI), 0.2 mmol of cesium iodide (CsI), 0.4 mmol of lead iodide (PbI2), 0.6 mmol of lead bromide (PbBr2) and 0.01 mmol of cesium acetate (CsAc, 1.92 mg) were mixed and added into 1 ml of a mixed solvent of DMF:DMSO:2-ME with a volume ratio of 8:1:1, and stirred for 1 h to obtain FA. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3 Initial perovskite ink. The above perovskite ink was coated on a glass substrate and then annealed on a hot plate at 100°C for 10 minutes to obtain a perovskite film, such as Figure 1 The photoluminescence spectra (PL) of the upper and lower surfaces are shown in Figure 2 shown.

[0054] Example 2

[0055] At room temperature, 0.8 mmol of iodomethane (FAI), 0.2 mmol of cesium iodide (CsI), 0.4 mmol of lead iodide (PbI2), 0.6 mmol of lead bromide (PbBr2) and 0.01 mmol of theophylline (1.80 mg) were mixed and added into 1 ml of a mixed solvent of ACN:2-ME with a volume ratio of 1:1, and stirred for 1 h to obtain FA. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4)3 Initial perovskite ink. The above perovskite ink was coated on a glass substrate and then annealed on a hot plate at 100°C for 10 minutes to obtain a perovskite film. The photoluminescence spectra (PL) of the upper and lower surfaces are shown in Figure 3 shown.

[0056] Example 3

[0057] At room temperature, 0.8 mmol of iodomethane (FAI), 0.2 mmol of cesium iodide (CsI), 0.4 mmol of lead iodide (PbI2), 0.6 mmol of lead bromide (PbBr2), 0.01 mmol of cesium acetate (CsAc, 1.92 mg) and 0.01 mmol of theophylline (Theophylline, 1.80 mg) were mixed and added into 1 ml of a mixed solvent of DMF: DMSO: ACN: 2-ME with a volume ratio of 7:1:1:1, and stirred for 1 h to obtain FA. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3 Initial perovskite ink. The above perovskite ink was coated on a glass substrate and then annealed on a hot plate at 100°C for 10 minutes to obtain a perovskite film. The photoluminescence spectra (PL) of the upper and lower surfaces are shown in Figure 4 shown.

[0058] Example 4

[0059] At room temperature, 2.7 mmol of methylamine iodide (MAI), 1.8 mmol of amylamine iodide (AAI), 3.6 mmol of lead iodide (PbI2), and 0.001 mmol of 6TIC-4F (1.57 mg) were mixed and added into 1 ml of a mixed solvent of DMF:DMSO:IPA with a volume ratio of 90:3:7, and stirred for 1 h to obtain (AA)2MA3Pb4I 13 Initial perovskite ink. The above perovskite ink was coated on a glass substrate and then annealed on a hot plate at 100°C for 10 minutes to obtain a perovskite film. The photoluminescence spectra (PL) of the upper and lower surfaces are shown in Figure 2. Figure 5 shown.

[0060] Comparative Example 1

[0061] At room temperature, 0.8 mmol of iodomethane (FAI), 0.2 mmol of cesium iodide (CsI), 0.4 mmol of lead iodide (PbI2) and 0.6 mmol of lead bromide (PbBr2) were mixed and added into 1 ml of a mixed solvent of DMF and DMSO in a ratio of 4:1, and stirred for 20 min to obtain FA. 0.8 Cs 0.2 Pb(I0.6 Br 0.4 )3 Initial perovskite ink. The above perovskite ink was coated on a glass substrate by slit coating, and then annealed on a hot plate at 100°C for 10 minutes to obtain a perovskite film. The photoluminescence spectra (PL) of the upper and lower surfaces are shown in Figure 2 or Figure 3 or Figure 4 shown.

[0062] Comparative Example 2

[0063] At room temperature, 2.7 mmol of methylamine iodide (MAI), 1.8 mmol of amylamine iodide (AAI), and 3.6 mmol of lead iodide (PbI2) were mixed and added into 1 ml of a mixed solvent of DMF:DMSO:IPA with a volume ratio of 90:3:7, and stirred for 1 h to obtain (AA)2MA3Pb4I 13 Initial perovskite ink. The above perovskite ink was coated on a glass substrate and then annealed on a hot plate at 100°C for 10 minutes to obtain a perovskite film. The photoluminescence spectra (PL) of the upper and lower surfaces are shown in Figure 2. Figure 5 shown.

[0064] The perovskite films prepared in the above-mentioned embodiments and comparative examples were tested by PL spectroscopy, and the peak photon number of PL intensity on the upper and lower surfaces of the perovskite films is shown in Table 1 below.

[0065] Table 1

[0066]

[0067] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the perovskite ink composition contains a perovskite precursor, a solvent and a passivator at the same time, and because the solvent contained is a mixed solvent with different boiling points, and the solubility of the same passivator is different, the volatility of the solvent can be brought into play when it is used in the process of preparing the perovskite film, and the passivator is integrated into the perovskite ink by utilizing the crystallization order from top to bottom in the preparation process. The perovskite ink formed by the perovskite ink composition can be applied to the preparation of highly crystalline and gradient-doped perovskite films, and can be used by scraping, inkjet printing, slit coating, roll-to-roll printing, etc., especially for the preparation process of large-area perovskite batteries, it can effectively improve production efficiency, simplify the process flow, and reduce production costs.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A perovskite ink composition, characterized in that: include: AX, BX2, solvent and passivator, wherein A represents a monovalent cation, B represents a divalent cation, and X represents a halogen ion; the solvent comprises at least two organic solvents with different boiling points, and the solvent comprises at least two organic solvents with different solubility in the passivator.

2. The composition according to claim 1, characterized in that The boiling point difference between the organic solvent with the highest boiling point and the organic solvent with the lowest boiling point among the solvents is 20 to 150°C; Preferably, the solvent includes at least two of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, γ-butyrolactone, 2-methoxyethanol, acetonitrile, ethanol, methanol, isopropanol, chlorobenzene, and ethyl acetate.

3. The composition according to claim 1, characterized in that The passivating agent includes any one or more of cesium acetate, cesium chloride, cesium iodide, cesium bromide, rubidium iodide, potassium chloride, 6TIC-4F, theophylline, caffeine, theobromine, 1-aminopyrene and phenylethylamine halide; Preferably, the molar ratio of the passivating agent to the AX is 1:1000 to 1:10; Preferably, the concentration of the passivating agent in the solvent is 0.1 to 10 mol%.

4. The composition according to claim 3, characterized in that The passivating agent includes any one or more of cesium acetate, cesium chloride, cesium iodide, cesium bromide, rubidium iodide, and potassium chloride, and the solvent includes at least one of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, and γ-butyrolactone; And / or, the passivating agent includes any one or more of 6TIC-4F, theophylline, caffeine, theobromine and 1-aminopyrene, and the solvent includes at least one of 2-methoxyethanol, acetonitrile, ethanol, methanol, isopropanol, chlorobenzene and ethyl acetate.

5. The composition according to claim 1, characterized in that The AX and BX2 can form ABX3 or A2(ABX3) n-1 BX4 structure; Preferably, the mixture formed by the composition is a homogeneous solution.

6. A perovskite ink, characterized in that: Prepared from the composition according to any one of claims 1 to 5.

7. A method for preparing a perovskite film, characterized in that: The perovskite ink according to claim 6 is placed on a substrate, and the solvent is evaporated to obtain a perovskite film.

8. The preparation method according to claim 7, characterized in that: The method of setting the perovskite ink includes any one of doctor blade coating, inkjet printing, slit coating and roll-to-roll printing; Preferably, the method of evaporating the solvent comprises any one of heating, gas extraction and laser-assisted annealing; Optionally, when the solvent is evaporated by heating, the heating temperature is 80-200°C.

9. A perovskite film, characterized in that: It is prepared by the preparation method according to claim 7 or 8.

10. A photovoltaic device, characterized in that: A perovskite thin film comprising the perovskite thin film according to claim 9.

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