Perovskite precursor solution and perovskite thin film and preparation method and application thereof

Abstract

The application discloses a perovskite precursor solution and a perovskite film as well as a preparation method and application thereof, the perovskite precursor solution comprises lead iodide, methyl amine iodide, an organic solvent and octyl amine chloride; the perovskite film is obtained by spin coating and near-infrared radiation treatment of the perovskite precursor solution. By adding the additive octyl amine chloride (OACl) in the preparation process of the perovskite precursor solution, the hydrophobicity of the perovskite is enhanced, the perovskite grain size is increased, and thus the stability and performance of the perovskite solar cell are improved. In addition, the perovskite precursor solution is directly heated by using the near-infrared method to achieve the effect of quickly removing the solvent, the temperature and the solvent evaporation rate are controlled by irradiation time, compared with the existing preparation technology, the organic solvent is quickly removed by dropwise adding an anti-solvent in the spin coating process, and thus the operation is more convenient, and the safety hidden danger is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of thin-film solar cells, and in particular to a perovskite precursor solution and a perovskite thin film, as well as a preparation method and application thereof. Background Art

[0002] Since the beginning of the 21st century, global energy has been dominated by fossil fuels, which cause significant environmental pollution. Therefore, clean, pollution-free renewable energy sources will be the primary energy sources used in the future to achieve carbon neutrality. Renewable energy sources such as ocean energy, wind energy, and solar energy have become important components of my country's energy mix. Solar energy is one of the cleanest and most affordable forms of energy. Photovoltaic power generation, as a form of solar radiation, boasts clean and sustainable characteristics. Perovskite solar cells (PSCs), as third-generation solar cells, have been extensively studied in recent years due to their low cost, high efficiency, and simple fabrication. Perovskite solar cells utilize photovoltaic efficiency to generate electricity. Under sunlight, excitons within the perovskite layer dissociate, generating free charge carriers. Electrons migrate freely to the cathode, while holes travel freely to the anode, creating a potential difference that generates current. The high absorption coefficient, tunable band gap, and long carrier lifetime of organic-inorganic perovskites enable ultra-high power conversion efficiencies (PCEs), currently exceeding 25%.

[0003] Perovskite films prepared using existing technologies often exhibit numerous surface defects, such as point defects (I- vacancies, Pb2+ vacancies) and surface defects (holes and high roughness). The inherent hydrophilicity of the material makes it extremely sensitive to humidity and temperature, resulting in low stability and a rapid degradation of performance. Spin coating methods for preparing perovskite films offer advantages such as simplicity and ease of operation. Typically, perovskite thin films are prepared by spin coating to obtain a wet perovskite film. During the spin coating process, an antisolvent is added to rapidly remove the organic solvent, followed by annealing and crystallization on a heating plate to form the perovskite film. This method has certain drawbacks, such as the precise timing of the antisolvent addition window, which can otherwise lead to the formation of numerous defects and reduced performance of perovskite solar cells. Furthermore, most antisolvents are highly toxic, posing safety risks. Therefore, optimizing the perovskite precursor solution used to prepare perovskite thin films and improving the film preparation process are crucial to improving the performance of perovskite solar cells. Summary of the Invention

[0004] The present invention addresses the technical problems of numerous defects in perovskite films prepared by prior art and potential safety hazards posed by the use of anti-solvents in the preparation process. The present invention aims to provide a perovskite precursor solution and perovskite film, as well as a preparation method and application thereof, that can improve the stability and performance of perovskite solar cells.

[0005] One of the objects of the present invention is to provide a perovskite precursor solution, which includes lead iodide (PbI2), methylammonium iodide (MAI), an organic solvent and octylammonium chloride (OACl).

[0006] Preferably, the concentration of the lead iodide is 0.8 to 1.2 mol / L; the concentration of the methylammonium iodide is 0.8 to 1.2 mol / L; the molar concentration of the octylammonium chloride is 1 to 5% of the molar concentration of the lead iodide;

[0007] The organic solvent is a mixed solution of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the volume ratio of the dimethylformamide to the dimethyl sulfoxide is 5:1 to 9:1.

[0008] Another object of the present invention is to provide a method for preparing a perovskite film, comprising the following steps:

[0009] S1. Preparing an electron transport layer on a clean substrate;

[0010] S2, preheating the perovskite precursor solution and the substrate prepared in step S1;

[0011] S3. Spin-coating the preheated perovskite precursor solution on the preheated substrate to obtain a perovskite wet film, and irradiating the perovskite wet film with near-infrared light during the spin-coating process to obtain a perovskite thin film.

[0012] Preferably, the method further comprises

[0013] S4, annealing the perovskite film obtained in step S3.

[0014] Preferably, the preheating in step S2 is: heating the substrate at 100-120° C. for 5-8 minutes, and heating the perovskite precursor solution to 50-70° C.;

[0015] The spin coating in step S3 is to spin-coat 30 to 50 μL of the perovskite precursor solution on a 1×1 cm 2 The spin coating speed is 3000 r / min to 4000 r / min on the substrate, and the spin coating time is 25 to 30 s; the radiation refers to irradiating the perovskite wet film with near-infrared light at a distance of 20 cm to 30 cm from the perovskite wet film 15 to 25 s after the spin coating is completed, the radiation time is 15 to 25 s, and the radiation intensity is 5 to 7 W / sr.

[0016] Preferably, the cleaned substrate in step S1 is prepared by ultrasonically cleaning the substrate with 100-130 mL of ethanol, detergent, deionized water, and ethanol in sequence for 15-20 minutes; drying the substrate at 50-70° C. for 5-10 minutes, and then treating the substrate with ultraviolet ozone for 15-20 minutes, wherein the ultraviolet ozone intensity is 28-32 mW / cm;

[0017] The preparation of the electron transport layer in step S1 is as follows: 15-17 wt% tin dioxide aqueous dispersion and ultrapure water are mixed in a volume ratio of 1:5 to obtain a tin oxide solution, and then 50-60 μL of the tin oxide solution is coated on a 1×1 cm 2 on a substrate, and then annealing at 140-150° C. for 25-30 min to obtain a tin dioxide electron transport layer.

[0018] Preferably, the perovskite precursor solution in step S2 is: 0.8-1.2 mmol of lead iodide and 0.8-1.2 mmol of methylammonium iodide are dissolved in 1 mL of an organic solvent, and then octyl ammonium chloride is added and stirred for 5-8 hours to obtain the perovskite precursor solution; wherein the molar amount of the octyl ammonium chloride is 1-5% of the molar amount of the lead iodide;

[0019] The organic solvent is a mixed solution of dimethylformamide and dimethyl sulfoxide, and the molar ratio of the dimethylformamide to the dimethyl sulfoxide is 5:1 to 9:1.

[0020] Preferably, the annealing in step S4 is to heat the perovskite film obtained in step S3 at 100-120° C. for 5-10 minutes.

[0021] Another object of the present invention is to provide an application of a perovskite film as a light absorption layer of a perovskite solar cell.

[0022] Preferably, the light absorbing layer of the perovskite solar cell is a perovskite layer;

[0023] The structure of the perovskite solar cell includes, in sequence: a glass substrate, an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode; or the structure of the perovskite solar cell includes, in sequence: a glass substrate, an electron transport layer, a perovskite layer and a carbon electrode.

[0024] The positive progress effect of the present invention is:

[0025] The present invention improves the performance of the perovskite film by adding an additive octylamine chloride (OACl) during the preparation of the perovskite precursor solution. The amino part in OACl can react with the Pb in the perovskite layer. 2+ Vacancies combine, and Cl can combine with I in the perovskite layer -The vacancies are combined to passivate the defects of the perovskite layer. The perovskite layer is extremely sensitive to moisture and will decompose in large quantities in an environment with high humidity. OACl has a long alkyl chain, which can enhance the hydrophobicity of the perovskite and increase the perovskite grain size, thereby improving the stability and performance of the perovskite solar cell. At the same time, the present invention also uses a near-infrared method to directly heat the perovskite precursor solution to achieve the effect of rapid solvent removal, and controls the temperature and solvent evaporation rate by the irradiation time. Compared with the existing preparation technology, the anti-solvent is added during the spin coating process to quickly remove the organic solvent, which is more convenient to operate and greatly reduces safety hazards. In addition, the preparation method combined with the near-infrared method and the carbon electrode and the additive octyl ammonium chloride (OACl) can achieve low-cost, high-performance and stable perovskite solar cells (PSC), which is very important for the future development strategy of achieving carbon neutrality. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] In Examples 1 to 3, perovskite solar cells were prepared, each having a cell structure consisting of a glass substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a silver metal electrode, wherein the glass substrate was indium tin oxide (ITO substrate).

[0028] Step S1: Prepare an electron transport layer on a clean substrate. 2 Indium tin oxide (ITO) glass substrates are sequentially placed on V 清洗溶液 Ultrasonic cleaning in mL ethanol, detergent, ultrapure water and ethanol 超声清洗 min, and then put the cleaned glass substrate into the oven at T 烘干 Drying at ℃ 烘干 min, the dried glass substrate is treated with UV ozone t 紫外臭氧处理 min. Mix 200 μL of 15 wt% tin dioxide (SnO2) aqueous dispersion with 1 mL of ultrapure water and stir thoroughly to obtain a tin oxide solution with a volume ratio of 1:5 between the tin dioxide colloidal dispersion and ultrapure water. Then take V 氧化锡 μL tin oxide solution is coated on a 1×1 cm 2 On the ITO glass substrate, place T 退火 Annealing on a heating plate at t 退火 min to obtain a tin dioxide electron transport layer.

[0029] Step S2: preheat the perovskite precursor solution and the substrate prepared in step S1. 碘化铅 mmol lead iodide (PbI2) and n 甲基碘化胺 mmol methylammonium iodide (MAI) was dissolved in a mixed solvent of dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) with a volume ratio of 9:1 (the total volume of the mixed solvent was 1 mL), and then n 辛基氯化胺 mmol of octyl ammonium chloride (OACl), stir thoroughly 搅拌 h to obtain the perovskite precursor solution.

[0030] The glass substrate on which the electron transport layer in step S1 was deposited was subjected to ultraviolet ozone treatment for 15 minutes. After the treatment, the glass substrate containing the electron transport layer was placed on a T 预热基板 Preheat on the heating table at t 预热基板 min, and the perovskite precursor solution is heated to T 前驱体溶液 ℃.

[0031] Step S3: Spin-coat the preheated perovskite precursor solution on the preheated substrate to obtain a perovskite wet film, and irradiate the perovskite wet film with near-infrared light during the spin-coating process to obtain a perovskite thin film. 2 The electron transport layer of tin dioxide is spin-coated on the surface of V 前驱体溶液 μL of the perovskite precursor solution was used to obtain a perovskite wet film, and the spin coating speed was V 旋涂 r / min, the spin coating time is t 旋涂 s, before the end of spin coating t 近红外光 s uses near-infrared light to generate a perovskite wet film S at a distance 辐射距离 Radiation treatment of perovskite wet film at t cm 近红外光 s to obtain perovskite thin films.

[0032] Step S4: annealing the perovskite film obtained in step S3. 加热薄膜 Heat on a heating table at t 加热薄膜 min to get 1×1cm 2 of the perovskite layer.

[0033] Step S5a, spin-coating the hole transport layer solution on the perovskite layer obtained in step S4, and obtaining the hole transport layer after sufficient oxidation. The hole transport layer solution is 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene solution, and the preparation method is as follows: dissolving 520mg of lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) in 1mL of acetonitrile to obtain lithium bis(trifluoromethanesulfonyl)imide solution, and then adding 17.5μL of lithium bis(trifluoromethanesulfonyl)imide solution, 28.8μL of 4-tert-butylpyridine and 1mL of chlorobenzene to 72.3mg of 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiroOMeTAD), and stirring thoroughly overnight to obtain a clear hole transport layer solution. Then take V 空穴传输层用溶液 μL of the hole transport layer solution was spin-coated on the 1×1 cm 2 On the perovskite layer, the spin coating speed is 4000 r / min, the spin coating time is 30 s, and then it is oxidized in air for 24 hours to obtain the hole transport layer.

[0034] Step S6: Evaporating a metal electrode on the hole transport layer: Using a ZHDS400 evaporator, a silver electrode is evaporated in a high vacuum to plate the silver metal onto the hole transport layer in step S5 to obtain a silver electrode.

[0035] In Examples 4 to 6, perovskite solar cells were prepared, each having a cell structure consisting of a glass substrate, an electron transport layer, a perovskite layer, and a carbon electrode, wherein the glass substrate was indium tin oxide (ITO substrate).

[0036] Step S1: Prepare an electron transport layer on a clean substrate. 2 Indium tin oxide (ITO) glass substrates are sequentially placed on V 清洗溶液 Ultrasonic cleaning in mL ethanol, detergent, ultrapure water and ethanol 超声清洗 min, and then put the cleaned glass substrate into the oven at T 烘干 Drying at ℃ 烘干 min, the dried glass substrate is treated with UV ozone t 紫外臭氧处理 min. Mix 200 μL of 15 wt% tin dioxide (SnO2) aqueous dispersion with 1 mL of ultrapure water and stir thoroughly to obtain a tin oxide solution. Then take V 氧化锡 μL tin oxide solution is coated on a 1×1 cm 2 ITO glass substrate, then placed on T 退火 Annealing on a heating plate at t 退火 min to obtain a tin dioxide electron transport layer.

[0037] Step S2: preheat the perovskite precursor solution and the substrate prepared in step S1. 碘化铅 mmol lead iodide (PbI2) and n 甲基碘化胺 mmol methylammonium iodide (MAI) was dissolved in a mixed solvent of dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) with a volume ratio of 9:1 (the total volume of the mixed solvent was 1 mL), and then n 辛基氯化胺 mmol of octyl ammonium chloride (OACl), stir thoroughly 搅拌 h formation concentration is C 前驱体溶液 mol / L perovskite precursor solution.

[0038] The glass substrate on which the electron transport layer in step S1 was deposited was subjected to ultraviolet ozone treatment for 15 minutes. After the treatment, the glass substrate containing the electron transport layer was placed on a T 预热基板 Preheat on the heating table at t 预热基板 min, and the perovskite precursor solution is heated to T 前驱体溶液 ℃.

[0039] Step S3: Spin-coat the preheated perovskite precursor solution on the preheated substrate to obtain a perovskite wet film, and irradiate the perovskite wet film with near-infrared light during the spin-coating process to obtain a perovskite thin film. 2 The electron transport layer of tin dioxide is spin-coated on the surface of V 前驱体溶液 μL of the perovskite precursor solution was used to obtain a perovskite wet film, and the spin coating speed was V 旋涂 r / min, the spin coating time is t 旋涂 s, before the end of spin coating t 近红外光 s uses near-infrared light to generate a perovskite wet film S at a distance 辐射距离 Radiation treatment of perovskite wet film at t cm 近红外光 s to obtain perovskite thin films.

[0040] Step S4: annealing the perovskite film obtained in step S3. 加热薄膜 Heat on a heating table at t 加热薄膜 min to get 1×1cm 2 of the perovskite layer.

[0041] Step S5b: Apply carbon slurry by scraping onto the perovskite layer obtained in step S4, and anneal the slurry to obtain a carbon electrode. A small amount of carbon slurry is applied directly to the surface of the perovskite layer obtained in step S4 using a glass slide to completely cover the entire surface of the perovskite layer. The slurry is then annealed at 100° C. for 30 minutes to obtain a carbon electrode.

[0042] The preparation steps of the perovskite solar cells of Examples 7 to 12 are consistent with the preparation steps of the corresponding Examples 1 to 6. The experimental parameters in the preparation processes of Examples 1 to 12 are shown in Table 1.

[0043] Table 1 Experimental parameters for preparing perovskite solar cells in Examples 1 to 12

[0044]

[0045]

[0046]

[0047] Table 1 Experimental parameters for preparing perovskite solar cells in Examples 1 to 12 (continued)

[0048]

[0049]

[0050]

[0051] Comparative Examples 1 to 3 prepare perovskite solar cells whose cell structures are glass substrate, electron transport layer, perovskite layer, hole transport layer and metal electrode silver in sequence, wherein the glass substrate is indium tin oxide (ITO substrate).

[0052] Comparative Examples 4 to 6 prepare perovskite solar cells whose cell structures are glass substrate, electron transport layer, perovskite layer and carbon electrode in sequence, wherein the glass substrate is indium tin oxide (ITO substrate).

[0053] The preparation processes of the comparative examples 1 to 6 are consistent with the preparation processes of the examples 1 to 6, with the differences shown in Table 2 below. The experimental parameters in the preparation processes are shown in Table 3.

[0054] Table 2 Summary of the differences between Examples 1 to 6 and Comparative Examples 1 to 6 during the preparation process

[0055] Additives in perovskite precursor solutions Method for removing organic solvents during spin coating Examples 1 to 6 Octyl ammonium chloride (OACl) Near-infrared method Comparative Example 1 - Near-infrared method Comparative Example 2 Octyl ammonium chloride (OACl) Antisolvent method Comparative Example 3 - Antisolvent method Comparative Example 4 - Near-infrared method Comparative Example 5 Octyl ammonium chloride (OACl) Antisolvent method Comparative Example 6 - Antisolvent method

[0056] The specific difference between the anti-solvent method and the near-infrared method in Table 2 is that in step S3, the preheated glass substrate is placed in a KW-4A spin coater at a temperature of 1×1 cm 2 The electron transport layer of tin dioxide is spin-coated on the surface of V 前驱体溶液The spin coating process of the perovskite wet film was obtained by spinning μL of the perovskite precursor solution. The spin coating process of removing the organic solvent by the anti-solvent method was divided into two steps: the first step was low-speed spin coating at a speed of 1000 r / min for 10 seconds, and the second step was high-speed spin coating at a speed of 4000 r / min for 30 seconds. Within 6 to 7 seconds of high-speed spin coating, the perovskite wet film was obtained by spinning the perovskite precursor solution on a 1×1 cm 2 150 μL of anti-solvent chlorobenzene was dropped onto the electron transport layer to remove the organic solvent to obtain a perovskite film.

[0057] Table 3 Comparative experimental parameters of perovskite solar cells prepared in Examples 1 to 6

[0058]

[0059]

[0060]

[0061] Performance Effect Example

[0062] The perovskite solar cell devices prepared in Examples 1 to 6 were irradiated using a CME-Sol8040-3A solar simulator at a light intensity of one sun AM1.5G. During the test, the device temperature was maintained at room temperature (25°C). During the test, the short-circuit current density (J) of the perovskite solar cell devices prepared in Examples 1 to 6 and Comparative Examples 1 to 6 was measured. SC ), open circuit voltage (V OC ), fill factor (FF) and power conversion efficiency (PCE) tests, and the test results are shown in Table 4.

[0063] Table 4 Performance test results of perovskite solar cell devices prepared in Examples 1 to 6 and Comparative Examples 1 to 6

[0064]

[0065] By comparing the test data of Example 1 and Comparative Example 1 (without OACl addition), and Example 4 and Comparative Example 4 (without OACl addition) in Table 4, it can be found that the fill factor (FF) and short-circuit current density (J SC ) has been significantly improved, indicating that the addition of octyl ammonium chloride (OACl) can effectively increase the grain size of the perovskite film and passivate the defects of the perovskite film, so that the prepared perovskite film has better surface morphology and density.

[0066] By comparing the test data of Example 2 and Comparative Example 2 (using the anti-solvent method) and Example 5 and Comparative Example 5 (using the anti-solvent method) in Table 4, it can be found that whether it is a silver electrode perovskite solar cell or a carbon electrode perovskite solar cell, compared with the perovskite solar cell prepared by removing the organic solvent using the anti-solvent method, the perovskite solar cell prepared by removing the organic solvent using the near-infrared method has a higher short-circuit current density (J SC ) and filling factor (FF), in other words, the perovskite film prepared by near-infrared treatment has better crystallinity and better film quality.

[0067] By comparing the test data of Example 3 and Comparative Example 3 (no OACl added and anti-solvent method adopted) and Example 6 and Comparative Example 6 (no OACl added and anti-solvent method adopted) in Table 4, it can be found that: whether it is a silver electrode perovskite solar cell or a carbon electrode perovskite solar cell, the perovskite solar cells prepared by combining the near-infrared method and the OACl addition method, i.e., Example 3 and Example 6, have a short-circuit current density (J SC ), open circuit voltage (V OC ) and fill factor (FF) are significantly improved, resulting in a power conversion efficiency (PCE) far greater than that of the perovskite solar cells prepared in Comparative Examples 3 and 6. In other words, the perovskite film prepared by combining the near-infrared method with the octylamine chloride (OACl) addition method can be significantly improved, with a smoother and denser surface and larger and more uniform grain size in the film.

[0068] In an inert atmosphere (N2), a CME-Sol8040-3A solar simulator was used to continuously irradiate the perovskite solar cell devices prepared in Example 3 and Comparative Example 3 (without adding octyl ammonium chloride (OACl) and using the anti-solvent method), and Example 6 and Comparative Example 6 (without adding octyl ammonium chloride (OACl) and using the anti-solvent method) at a light intensity of one sunlight intensity AM1.5G. The power conversion efficiency (PCE) attenuation of the devices was tested. The test results are shown in Table 5.

[0069] Table 5 Performance attenuation test of perovskite solar cell devices prepared in Example 3 and Comparative Example 3, Example 6 and Comparative Example 6

[0070]

[0071] As can be seen from Table 5 above, the performance of the perovskite solar cell devices prepared in Comparative Example 3 and Comparative Example 6 dropped sharply within the first 100 hours, and then stabilized and slightly dropped to 50-60% of the initial power conversion efficiency after 500 hours. In contrast, the perovskite solar cell devices prepared in Example 3 and Example 6 using a near-infrared method and the addition of octylamine chloride (OACl) were able to maintain a power conversion efficiency (PCE) of more than 80% of the initial power conversion efficiency (PCE) after 100 hours under the same environmental conditions, and still maintained more than 80% of the initial power conversion efficiency (PCE) after 500 hours. In summary, when the perovskite film prepared by the present invention is used as a light absorption layer in a perovskite solar cell device, the stability and performance of the perovskite solar cell device are superior to those of the perovskite solar cell device prepared by the prior art.

[0072] The present invention has been described in detail above with reference to the embodiments. A person skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the present invention shall be protected within the scope defined by the appended claims.

Claims

1. A method for preparing a perovskite film, characterized in that The method comprises the following steps: S1. Preparing an electron transport layer on a clean substrate; S2. Preheating the perovskite precursor solution and the substrate prepared in step S1; wherein the perovskite precursor solution comprises lead iodide, methylammonium iodide, an organic solvent, and octylammonium chloride; S3, spin-coating the preheated perovskite precursor solution on the preheated substrate to obtain a perovskite wet film, and irradiating the perovskite wet film with near-infrared light during the spin-coating process to obtain a perovskite thin film; The preheating in step S2 is to heat the substrate at 100-120° C. for 5-8 minutes and heat the perovskite precursor solution to 50-70° C.; The irradiation in step S3 refers to irradiating the perovskite wet film with near-infrared light 15 to 25 seconds after the spin coating is completed.

2. The method according to claim 1, wherein The concentration of the lead iodide is 0.8-1.2 mol / L; the concentration of the methylammonium iodide is 0.8-1.2 mol / L; the molar concentration of the octylammonium chloride is 1-5% of the molar concentration of the lead iodide; The organic solvent is a mixed solution of dimethylformamide and dimethyl sulfoxide, and the volume ratio of the dimethylformamide to the dimethyl sulfoxide is 5:1 to 9:

1.

3. The method according to claim 1, wherein The method further includes S4, annealing the perovskite film obtained in step S3.

4. The method according to claim 1, wherein The spin coating in step S3 is to spin-coat 30~50 μL of the perovskite precursor solution on a 1×1 cm 2 The spin coating speed is 3000 r / min~4000 r / min on the substrate, and the spin coating time is 25~30 s; the radiation refers to irradiating the perovskite wet film with near-infrared light at a distance of 20 cm~30 cm from the perovskite wet film, the radiation time is 15~25 s, and the radiation intensity is 5~7 W / sr.

5. The method according to claim 1, wherein The cleaned substrate in step S1 is cleaned by ultrasonically cleaning the substrate with 100-130 mL of ethanol, detergent, deionized water, and ethanol in sequence for 15-20 minutes; drying the substrate at 50-70° C. for 5-10 minutes, and then treating the substrate with ultraviolet ozone for 15-20 minutes at an intensity of 28-32 mW / cm; The preparation of the electron transport layer in step S1 is as follows: 15-17 wt% tin dioxide aqueous dispersion is mixed with ultrapure water in a volume ratio of 1:5 to obtain a tin oxide solution, and then 50-60 μL of the tin oxide solution is coated on a 1×1 cm 2 The SnO2 electron transport layer was obtained by annealing at 140-150 °C for 25-30 min.

6. The method according to claim 1, wherein The perovskite precursor solution in step S2 is prepared by dissolving 0.8-1.2 mmol of lead iodide and 0.8-1.2 mmol of methylammonium iodide in 1 mL of an organic solvent, adding octyl ammonium chloride, and stirring for 5-8 hours. The molar amount of octyl ammonium chloride is 1-5% of the molar amount of lead iodide. The organic solvent is a mixed solution of dimethylformamide and dimethyl sulfoxide, and the molar ratio of the dimethylformamide to the dimethyl sulfoxide is 5:1 to 9:

1.

7. The method according to claim 3, wherein The annealing in step S4 refers to heating the perovskite film obtained in step S3 at 100-120° C. for 5-10 minutes.

8. Use of the perovskite film prepared by the method according to claim 1 as a light absorption layer of a perovskite solar cell.

9. The use according to claim 8, characterized in that The light absorbing layer of the perovskite solar cell is a perovskite layer; The structure of the perovskite solar cell includes, in sequence: a glass substrate, an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode; or The structure of the perovskite solar cell includes: a glass substrate, an electron transport layer, a perovskite layer and a carbon electrode in sequence.

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