A method for improving the quality of perovskite film for solar cells, perovskite solar cell and preparation method thereof

Abstract

The present application provides a method for improving the quality of a perovskite film for a solar cell, a perovskite solar cell, and a preparation method. The method for improving the quality of a perovskite film for a solar cell comprises the following steps: preparing a perovskite precursor solution; performing irradiation nucleation treatment on the prepared perovskite precursor solution using a laser; coating the perovskite precursor solution after the irradiation nucleation treatment on a substrate to obtain a perovskite film. The method has the beneficial effect of improving the uniformity, crystallization quality, and photoelectric performance of the prepared perovskite film, and is applicable to the technical field of perovskite solar cells.

Description

Technical Field

[0001] The present application relates to the field of perovskite solar cells, and in particular to a method for improving the quality of perovskite thin films for solar cells, a perovskite solar cell and a preparation method thereof. Background Art

[0002] Perovskite solar cells are a new solar cell technology that has garnered significant attention in recent years. Their unique materials and structural design make them a significant innovation in the solar energy field. Perovskite solar cells utilize a thin perovskite film as a light-absorbing layer. This material enables highly efficient photoelectric conversion and is relatively simple to manufacture, potentially significantly reducing production costs. Compared to traditional silicon-based solar cells, perovskite solar cells offer numerous advantages, including simplified manufacturing, flexible design, and excellent performance in low-light conditions. These advantages have garnered significant attention and are considered a key area of ​​future solar cell technology development.

[0003] In perovskite solar cell devices, the quality of the perovskite film plays a crucial role in device performance. The better the crystallinity and larger the grain size of the perovskite layer, the better the device performance. Perovskite precursors are the materials used to prepare perovskite films. Currently, a common method to improve device performance is to add additives with specific functional groups to the precursors. Lasers are often used to control nucleation in perovskite films, but this preparation process is complex and costly. Summary of the Invention

[0004] In order to solve one of the above technical defects, the present application provides a method for improving the quality of perovskite films for solar cells, a perovskite solar cell and a preparation method.

[0005] According to a first aspect of the present application, there is provided a method for improving the quality of a perovskite thin film for a solar cell, comprising the following steps:

[0006] Prepare perovskite precursor solution;

[0007] The prepared perovskite precursor solution is irradiated with laser for nucleation treatment;

[0008] The perovskite precursor solution after irradiation nucleation treatment is coated on a substrate to obtain a perovskite film.

[0009] Preferably, the perovskite precursor solution is any one of narrow-bandgap perovskite precursor solutions, or any one of wide-bandgap perovskite precursor solutions, or any one of intermediate-bandgap perovskite precursor solutions.

[0010] More preferably, the narrow bandgap perovskite precursor solution has a bandgap of 1.2 to 1.3 eV, and the narrow bandgap perovskite precursor solution comprises: FA 0.7 MA 0.3 Sn 0.5 Pb 0.5 I3 perovskite precursor solution, Cs 0.05 FA 0.5 MA 0.45 Pb 0.5 Sn 0.5 I3 perovskite precursor solution, Cs 0.1 FA 0.6 MA 0.3 Pb 0.5 Sn 0.5 I3 perovskite precursor solution;

[0011] The band gap of the wide band gap perovskite precursor solution is 1.63 to 2.3 eV, and the wide band gap perovskite precursor solution includes: FA 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3Perovskite precursor solution, FA 0.91 Cs 0.09 PbI 2.3 Br 0.7 Perovskite precursor solution, FA 0.8 Cs 0.2 Pb(I 0.7 Br 0.3 )3Perovskite precursor solution;

[0012] The intermediate bandgap perovskite precursor solution has a bandgap of 1.3 to 1.63 eV, and the intermediate bandgap perovskite precursor solution comprises: MA 0.7 FA 0.3 PbI3 perovskite precursor solution, Cs 0.03 (FA 0.97 MA 0.03 ) 0.97 Pb(I 0.97 Br 0.03 )3Perovskite precursor solution, FA 0.85 Cs 0.15 PbI 2.85 Br 0.15 Perovskite precursor solution.

[0013] Preferably, the preparation of the perovskite precursor solution comprises the following steps: weighing raw materials: 47.8 mg of CsBr, 219.3 mg of FAI and 691.5 mg of PbI2; dissolving the weighed raw materials in 1000 μl of a mixed solution, wherein the volume ratio of the mixed solution is DMF:DMSO=4:1; and stirring until the solution is transparent to obtain FA. 0.85 Cs 0.15 PbI 2.85 Br 0.15 Perovskite precursor solution.

[0014] Preferably, the laser is a femtosecond pulse laser, and the wavelength of the femtosecond pulse laser is 343-1030 nm and the average power is 200 mW.

[0015] Preferably, the substrate is ITO glass or FTO glass.

[0016] According to a second aspect of the present application, a method for preparing a perovskite solar cell is provided, wherein the perovskite solar cell has a formal structure or a trans structure; the perovskite solar cell includes a light absorption layer, and the light absorption layer is a perovskite film prepared by the method for improving the quality of perovskite films for solar cells as described in any of the above items.

[0017] Preferably, the method comprises the following steps: pre-treating the substrate; sequentially X The solution, the perovskite precursor solution after nucleation irradiation treatment, the PEAI solution, the PCBM solution and the BCP solution are coated on the pretreated substrate; the Ag electrode is evaporated in an evaporator to obtain a perovskite solar cell.

[0018] Preferably, the pretreatment of the substrate comprises the following steps: ultrasonically cleaning the substrate with detergent water, glass water, deionized water, anhydrous ethanol, acetone and isopropyl alcohol for a total of 20 minutes; then drying the substrate in an oven at 100°C for 30 minutes; and finally treating the substrate with ultraviolet-ozone for 20 minutes to remove surface organic matter.

[0019] According to a third aspect of the present application, a perovskite solar cell is provided, which is prepared using the above-described method for preparing a perovskite solar cell.

[0020] The perovskite film prepared by the method for improving the quality of perovskite films for solar cells provided by the present application has fewer surface pinholes, high crystallinity, dense grain distribution, and large grain size. In the present application, a femtosecond pulse laser is used to perform irradiation nucleation treatment on a configured perovskite precursor solution. The high peak power and ultrashort pulse characteristics of the femtosecond pulse laser enable the perovskite precursor solution to absorb photon energy, reducing the nucleation barrier of the perovskite precursor solution, facilitating nucleation, and the formed crystal nuclei can adsorb precursor molecules in the surrounding precursor solution, promote the formation of high-quality crystals, and improve the quality of the perovskite precursor solution. This can further improve the uniformity, crystallization quality, and photoelectric properties of the prepared perovskite film. At the same time, since laser irradiation is non-contact, direct contact with the outside world is avoided, and the perovskite precursor solution will not be contaminated or damaged, thus avoiding the deformation and stress concentration problems of the prepared perovskite film. The problem of chemical pollution and resource waste caused by adding additives with specific functional groups to improve the quality of perovskite films in the prior art is solved.

[0021] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the contents indicated in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0023] Figure 1 A structural diagram of a femtosecond pulse laser provided in Example 1 of the present application performing irradiation nucleation treatment on a perovskite precursor solution;

[0024] Figure 2 Dynamic light scattering diagrams of the perovskite precursor solution after irradiation nucleation treatment provided in Example 1 of the present application and the perovskite precursor solution provided in Comparative Example 1;

[0025] Figure 3 This is an SEM image of the perovskite film provided in Example 1 of the present application;

[0026] Figure 4 This is an SEM image of the perovskite film provided in Comparative Example 1 of this application;

[0027] Figure 5 X-ray diffraction patterns of the perovskite films provided in Example 1 and Comparative Example 1 of the present application;

[0028] Figure 6Performance diagram of the perovskite solar cell provided in Example 2, Example 3, Example 4 and Comparative Example 2 of the present application;

[0029] Figure 7 Performance diagram of the perovskite solar cell provided in Example 2 and Comparative Example 3 of the present application;

[0030] Figure 8 The inverse structure diagram of the perovskite solar cell provided in this application;

[0031] In the picture:

[0032] 1 is a femtosecond pulse laser, and 2 is a container. DETAILED DESCRIPTION

[0033] In order to make the technical solutions and advantages of the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, and are not an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless they conflict.

[0034] Example 1

[0035] Embodiment 1 of the present application provides a method for improving the quality of a perovskite thin film for a solar cell, comprising the following steps:

[0036] Prepare the perovskite precursor solution, including:

[0037] Weigh the raw materials: 47.8 mg cesium bromide (CsBr), 219.3 mg

[0038] Lead iodide (PbI2);

[0039] The weighed raw materials were dissolved in 1000 μl of a mixed solution with a volume ratio of DMF:DMSO = 4:1;

[0040] Then stir until the solution is transparent to obtain FA 0.85 Cs 0.15 PbI 2.85 Br 0.15 Perovskite precursor solution;

[0041] The prepared perovskite precursor solution is irradiated with a femtosecond pulse laser with a wavelength of 1030 nm and an average power of 200 mW for nucleation treatment; Figure 1 As shown, the perovskite precursor solution is placed in a container 2 and then irradiated by a femtosecond pulse laser 1;

[0042] The perovskite precursor solution after irradiation nucleation treatment is coated on a substrate to obtain a perovskite film; the substrate is ITO glass or FTO glass.

[0043] The perovskite film prepared by the method for improving the quality of perovskite films for solar cells provided by the present application has fewer surface pinholes, high crystallinity, dense grain distribution, and large grain size. In the present application, a femtosecond pulse laser is used to perform irradiation nucleation treatment on a configured perovskite precursor solution. The high peak power and ultrashort pulse characteristics of the femtosecond pulse laser enable the perovskite precursor solution to absorb photon energy, reducing the nucleation barrier of the perovskite precursor solution, facilitating nucleation, and the formed crystal nuclei can adsorb precursor molecules in the surrounding precursor solution, promote the formation of high-quality crystals, and improve the quality of the perovskite precursor solution. This can further improve the uniformity, crystallization quality, and photoelectric properties of the prepared perovskite film. At the same time, since laser irradiation is non-contact, direct contact with the outside world is avoided, and the perovskite precursor solution will not be contaminated or damaged, thus avoiding the deformation and stress concentration problems of the prepared perovskite film. The problem of chemical pollution and resource waste caused by adding additives with specific functional groups to improve the quality of perovskite films in the prior art is solved.

[0044] Example 2

[0045] A second embodiment of the present application provides a method for preparing a perovskite solar cell, wherein the perovskite solar cell has an inverted structure; the perovskite solar cell includes a light absorption layer, and the light absorption layer is a perovskite thin film prepared by the method for improving the quality of a perovskite thin film for a solar cell described in the first embodiment; the method comprises the following steps:

[0046] The substrate is pretreated, specifically comprising the following steps:

[0047] The substrate was ultrasonically cleaned in detergent water, glass water, deionized water, anhydrous ethanol, acetone, and isopropyl alcohol for a total of 20 minutes;

[0048] Then dry in a 100°C oven for 30 minutes;

[0049] Finally, the samples were treated with UV-ozone for 20 minutes to remove surface organic matter.

[0050] NiO X solution, perovskite precursor solution after nucleation irradiation treatment, PEAI solution, PCBM solution and BCP solution were coated on the pretreated substrate;

[0051] By evaporating Ag electrodes in an evaporation machine, you can get perovskite solar cells.

[0052] Specifically, NiO XThe solution is the HTL layer in the perovskite solar cell; the perovskite precursor solution after nucleation irradiation treatment is the Perovskite layer in the perovskite solar cell; the PEAI solution is the passivation layer, which can passivate the defects of the Perovskite layer; the PCBM solution is the ETL layer in the perovskite solar cell; the BCP solution is the buffer layer, which can buffer the electron transfer between the ETL layer and the Ag electrode.

[0053] Example 3

[0054] A third embodiment of the present application provides a method for preparing a perovskite solar cell, wherein the perovskite solar cell has an inverted structure; the perovskite solar cell includes a light absorption layer, and the light absorption layer is a perovskite thin film prepared by irradiating a prepared perovskite precursor solution with a femtosecond pulse laser having a wavelength of 343 nm and an average power of 200 mW to form a nucleus; the preparation method comprises the following steps:

[0055] The substrate is pretreated, specifically comprising the following steps:

[0056] The substrate was ultrasonically cleaned in detergent water, glass water, deionized water, anhydrous ethanol, acetone, and isopropyl alcohol for a total of 20 minutes;

[0057] Then dry in a 100°C oven for 30 minutes;

[0058] Finally, the samples were treated with UV-ozone for 20 minutes to remove surface organic matter.

[0059] NiO X solution, perovskite precursor solution after nucleation irradiation treatment, PEAI solution, PCBM solution and BCP solution were coated on the pretreated substrate;

[0060] By evaporating Ag electrodes in an evaporation machine, you can get perovskite solar cells.

[0061] Example 4

[0062] A fourth embodiment of the present application provides a method for preparing a perovskite solar cell, wherein the perovskite solar cell has an inverted structure; the perovskite solar cell includes a light absorption layer, and the light absorption layer is a perovskite thin film prepared by irradiating a prepared perovskite precursor solution with a femtosecond pulse laser having a wavelength of 515 nm and an average power of 200 mW to form a nucleus; the preparation method comprises the following steps:

[0063] The substrate is pretreated, specifically comprising the following steps:

[0064] The substrate was ultrasonically cleaned in detergent water, glass water, deionized water, anhydrous ethanol, acetone, and isopropyl alcohol for a total of 20 minutes;

[0065] Then dry in a 100°C oven for 30 minutes;

[0066] Finally, the samples were treated with UV-ozone for 20 minutes to remove surface organic matter.

[0067] NiO X solution, perovskite precursor solution after nucleation irradiation treatment, PEAI solution, PCBM solution and BCP solution were coated on the pretreated substrate;

[0068] By evaporating Ag electrodes in an evaporation machine, you can get perovskite solar cells.

[0069] By adopting the preparation method of the perovskite solar cell provided in the present application, since the perovskite precursor solution after the nucleation irradiation treatment is directly coated on the substrate, the various index parameters of the prepared perovskite solar cell are: short circuit current density J SC , open circuit voltage V OC , fill factor (FF) and solar-to-electricity efficiency (PCE) are all improved. At the same time, it can shorten the preparation time, facilitate expansion into industrial production, and further save manufacturing costs.

[0070] In order to demonstrate the beneficial effects of Example 1, Example 2, Example 3 and Example 4 of the present application, Comparative Example 1, Comparative Example 2 and Comparative Example 3 are listed below.

[0071] Comparative Example 1

[0072] Comparative Example 1 of the present application provides a method for improving the quality of a perovskite film for a solar cell, comprising the following steps:

[0073] Prepare the perovskite precursor solution, including:

[0074] Weigh the following raw materials: 47.8 mg of cesium bromide (CsBr), 219.3 mg of formamidine hydroiodide (FAI), and 691.5 mg of lead iodide (PbI2);

[0075] The weighed raw materials were dissolved in 1000 μl of a mixed solution with a volume ratio of DMF:DMSO = 4:1;

[0076] Then stir until the solution is transparent to obtain the perovskite precursor solution FA 0.85 Cs 0.15 PbI 2.85 Br 0.15 ;

[0077] The perovskite precursor solution was coated on an ITO glass substrate to obtain a perovskite film.

[0078] Figure 2The dynamic light scattering diagram of the perovskite precursor solution after irradiation nucleation treatment provided in Example 1 of the present application and the perovskite precursor solution provided in Comparative Example 1 is as follows: Figure 2 As shown, the size of the colloids in the perovskite precursor solution after the irradiation nucleation treatment in Example 1 is relatively large.

[0079] Figure 3 This is a SEM image of the perovskite film provided in Example 1 of this application. Figure 4 The SEM image of the perovskite film provided in Comparative Example 1 of this application is as follows: Figure 3 、 Figure 4 As shown, the perovskite film prepared in Example 1 has fewer surface pinholes and larger grain size than the perovskite film prepared in Comparative Example 1.

[0080] Figure 5 The X-ray diffraction patterns of the perovskite films provided in Example 1 and Comparative Example 1 of the present application are as follows: Figure 5 As shown, the perovskite film is strongest at the (001) peak. Compared with the comparative example 1, the (001) / (011) ratio of the perovskite film provided in Example 1 increases from 3.28 to 5.12, the (001) / (111) ratio increases from 5.67 to 7.16, the (001) / (002) ratio increases from 1.65 to 1.73, the (001) / (012) ratio increases from 1.66 to 2.63, and the (001) / (022) ratio increases from 2.81 to 4.29. Therefore, the perovskite film provided in Example 1 has a stronger crystallinity than the perovskite film provided in Comparative Example 1.

[0081] Comparative Example 2

[0082] Comparative Example 2 of the present application provides a method for preparing a perovskite solar cell. Compared with Example 2, the difference is that:

[0083] 1. The light absorbing layer is a perovskite film prepared by the method for improving the quality of perovskite films for solar cells described in Comparative Example 1;

[0084] 2. Sequentially add NiO X solution, perovskite precursor solution, PEAI solution, PCBM solution and BCP solution are coated on the substrate.

[0085] Figure 6 The performance diagram of the perovskite solar cell provided in Example 2, Example 3, Example 4 and Comparative Example 2 of this application is as follows: Figure 6 As shown, the performance of the perovskite solar cells prepared in Example 2, Example 3 and Example 4 compared with the perovskite solar cell prepared in Comparative Example 2: short-circuit current density J SC , open circuit voltage V OC, fill factor FF and solar power conversion efficiency PCE are all improved. Among them, the short-circuit current density J SC Example 2 increased 0.51 mA·cm compared with Comparative Example 2. -2 The third embodiment increases 0.59 mA·cm compared with the second comparative embodiment. -2 The fourth embodiment increases 0.56 mA·cm compared with the second comparative embodiment. -2 ; Open circuit voltage V OC The second embodiment increases by 0.0269V compared with the second comparative example, the third embodiment increases by 0.0032V compared with the second comparative example, and the fourth embodiment increases by 0.0042V compared with the second comparative example; the fill factor FF of the second embodiment increases by 3.43% compared with the second comparative example, the third embodiment increases by 1.94% compared with the second comparative example, and the fourth embodiment increases by 1.49% compared with the second comparative example; the solar energy conversion efficiency PCE of the second embodiment increases by 1.74% compared with the second comparative example, the third embodiment increases by 1.23% compared with the second comparative example, and the fourth embodiment increases by 0.79% compared with the second comparative example.

[0086] Comparative Example 3

[0087] Comparative Example 3 of the present application provides a method for preparing a perovskite solar cell. Compared with Comparative Example 2, the difference is that:

[0088] After the perovskite precursor solution is coated on the substrate to form a perovskite film, the perovskite film is irradiated with a femtosecond pulse laser with a wavelength of 1030 nm and an average power of 200 mW;

[0089] Then, PEAI solution, PCBM solution and BCP solution were coated on the substrate in sequence.

[0090] Figure 7 The performance diagram of the perovskite solar cell provided in Example 2 and Comparative Example 3 of this application is as follows: Figure 7 As shown, the performance of the perovskite solar cell prepared in Example 2 compared with the perovskite solar cell prepared in Comparative Example 3: short-circuit current density J SC Increase by 0.41 mA·cm -2 , open circuit voltage V OC The results show that the voltage increased by 0.061V, the fill factor (FF) increased by 10.4%, and the solar-to-electricity efficiency (PCE) increased by 4.01%. Therefore, the method of using laser to irradiate the perovskite precursor solution for nucleation treatment and then coating the irradiated nucleation-treated perovskite precursor solution on a substrate to obtain a perovskite film has better performance than the method of directly irradiating the perovskite film with laser, and can shorten the preparation time of the cell, which can effectively save costs.

[0091] Figure 8The inverse structure diagram of the perovskite solar cell provided in this application is as follows: Figure 8 As shown, the present application also provides a perovskite solar cell with an inverted structure, that is, it is prepared by the preparation method of the perovskite solar cell described in Example 2. The perovskite solar cell includes, from bottom to top: a substrate (Glass), a base (ITO glass or FTO glass), a hole transport layer (HTL), a light absorption layer (perovskite film Perovskite), an electron transport layer (ETL), and a top electrode (Ag);

[0092] It can also be a formal structure. The perovskite solar cell includes from bottom to top: substrate, base, electron transport layer, light absorption layer, hole transport layer, and top electrode.

[0093] Since the perovskite thin film prepared in Example 1 of the present application has a large grain size, the perovskite solar cell prepared therefrom has good performance.

[0094] For the purpose of being concise and saving space, this application uses FA 0.85 Cs 0.15 PbI 2.85 Br 0.15 The examples and comparative examples are listed using the perovskite precursor solution as an example, which is not intended to limit the perovskite precursor solution. In fact, the perovskite precursor solution can be CH(NH2)2PbI3 perovskite precursor solution, CH(NH2)2PbBr3 perovskite precursor solution, CH3NH3PbBr3 perovskite precursor solution, CH3NH3PbI3 perovskite precursor solution, CH3NH3PbI 3-X Cl X CH(NH2)2PbI 3-X Cl X One or more perovskite precursor solutions, or any one of narrow-bandgap perovskite precursor solutions, or any one of wide-bandgap perovskite precursor solutions, or any one of intermediate-bandgap perovskite precursor solutions. The narrow-bandgap perovskite precursor solution has a bandgap of 1.2 to 1.3 eV, and the narrow-bandgap perovskite precursor solution includes: FA 0.7 MA 0.3 Sn 0.5 Pb 0.5 I3 perovskite precursor solution, Cs 0.05 FA 0.5 MA 0.45 Pb 0.5 Sn 0.5 I3 perovskite precursor solution, Cs 0.1 FA 0.6 MA 0.3 Pb 0.5 Sn 0.5I3 perovskite precursor solution; the band gap of the wide band gap perovskite precursor solution is 1.63 to 2.3 eV, and the wide band gap perovskite precursor solution includes: FA 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3Perovskite precursor solution, FA 0.91 Cs 0.09 PbI 2.3 Br 0.7 Perovskite precursor solution, FA 0.8 Cs 0.2 Pb(I 0.7 Br 0.3 )3 perovskite precursor solution; the band gap of the intermediate band gap perovskite precursor solution is 1.3 to 1.63 eV, and the intermediate band gap perovskite precursor solution includes: MA 0.7 FA 0.3 PbI3 perovskite precursor solution, Cs 0.03 (FA 0.97 MA 0.03 ) 0.97 Pb(I 0.97 Br 0.03 )3Perovskite precursor solution, FA 0.85 Cs 0.15 PbI 2.85 Br 0.15 Perovskite precursor solution.

[0095] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0096] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for improving the quality of perovskite thin films for solar cells, characterized in that: The following steps are involved: Prepare perovskite precursor solution; The prepared perovskite precursor solution is irradiated with laser for nucleation treatment; The perovskite precursor solution after irradiation nucleation treatment is coated on a substrate to obtain a perovskite film; The perovskite precursor solution is any one of narrow-bandgap perovskite precursor solutions, or any one of wide-bandgap perovskite precursor solutions, or any one of intermediate-bandgap perovskite precursor solutions; The narrow bandgap perovskite precursor solution includes: FA 0.7 MA 0.3 Sn 0.5 Pb 0.5 I3 perovskite precursor solution, Cs 0.05 FA 0.5 MA 0.45 Pb 0.5 Sn 0.5 I3 perovskite precursor solution, Cs 0.1 FA 0.6 MA 0.3 Pb 0.5 Sn 0.5 I3 perovskite precursor solution; The wide bandgap perovskite precursor solution includes: FA 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3Perovskite precursor solution, FA 0.91 Cs 0.09 PbI 2.3 Br 0.7 Perovskite precursor solution, FA 0.8 Cs 0.2 Pb(I 0.7 Br 0.3 )3Perovskite precursor solution; The intermediate bandgap perovskite precursor solution includes: MA 0.7 FA 0.3 PbI3 perovskite precursor solution, Cs 0.03 (FA 0.97 MA 0.03 ) 0.97 Pb(I 0.97 Br 0.03 )3Perovskite precursor solution, FA 0.85 Cs 0.15 PbI 2.85 Br 0.15 Perovskite precursor solution.

2. The method for improving the quality of perovskite thin films for solar cells according to claim 1, characterized in that: The band gap of the narrow-bandgap perovskite precursor solution is 1.2-1.3 eV, the band gap of the wide-bandgap perovskite precursor solution is 1.63-2.3 eV, and the band gap of the intermediate-bandgap perovskite precursor solution is 1.3-1.63 eV.

3. The method for improving the quality of perovskite thin films for solar cells according to claim 1, characterized in that: The preparation of the perovskite precursor solution comprises the following steps: Weigh the raw materials: 47.8 mg of CsBr, 219.3 mg of FAI and 691.5 mg of PbI2; The weighed raw materials were dissolved in 1000 μl of a mixed solution with a volume ratio of DMF:DMSO = 4:1; Then stir until the solution is transparent to obtain FA 0.85 Cs 0.15 PbI 2.85 Br 0.15 Perovskite precursor solution.

4. The method for improving the quality of perovskite thin films for solar cells according to claim 1, characterized in that: The laser is a femtosecond pulse laser with a wavelength of 343-1030 nm and an average power of 200 mW.

5. The method for improving the quality of perovskite thin films for solar cells according to claim 1, characterized in that: The substrate is ITO glass or FTO glass.

6. A method for preparing a perovskite solar cell, characterized in that: The perovskite solar cell is a regular structure or a trans structure; The perovskite solar cell includes a light absorbing layer, and the light absorbing layer is a perovskite thin film prepared by the method for improving the quality of a perovskite thin film for a solar cell according to any one of claims 1 to 5.

7. The method for preparing a perovskite solar cell according to claim 6, wherein: The following steps are involved: Pre-treating the substrate; NiO X The solution, the perovskite precursor solution after nucleation irradiation treatment, the PEAI solution, the PCBM solution and the BCP solution are coated on the pretreated substrate; the Ag electrode is evaporated in an evaporator to obtain a perovskite solar cell.

8. The method for preparing a perovskite solar cell according to claim 7, wherein: The substrate is pretreated, comprising the following steps: The substrate was ultrasonically cleaned in detergent water, glass water, deionized water, anhydrous ethanol, acetone, and isopropyl alcohol for a total of 20 minutes; Then dry in a 100°C oven for 30 minutes; Finally, the samples were treated with UV-ozone for 20 minutes to remove surface organic matter.

9. A perovskite solar cell, characterized in that: The perovskite solar cell is prepared using the method for preparing the perovskite solar cell according to claim 7 or 8.

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