Thermal shock resistant perovskite solar cell and preparation method thereof

Abstract

The invention provides a thermal shock resistant perovskite solar cell and a preparation method thereof. The thermal shock resistant perovskite solar cell sequentially comprises a conductive substrate, an electron transport layer, a light absorption layer, a hole transport layer and a metal electrode layer from bottom to top, and an FPI layer is introduced between a perovskite layer and the electron transport layer. The FPI molecular passivation layer introduced by the method is anchored on a TiO2 and perovskite interface through a unique'molecular bridge 'structure, so that the modulus difference between a perovskite layer and an electron transport layer is greatly reduced, the release of interface stress is remarkably promoted, and meanwhile, the interface stress energy is reduced; 2, the occurrence of a perovskite thin film phase separation phenomenon and the generation of degradation products are inhibited; thirdly, the vertical growth of perovskite thin film crystal grains and the carrier transport efficiency are promoted; higher photoelectric conversion efficiency and good long-term stability are realized. The perovskite solar cell prepared by the method has the characteristics of simple process, excellent stability, good repeatability and the like, is suitable for large-scale popularization and application, and has a good application prospect.

Description

Technical Field

[0001] This application belongs to the field of perovskite solar cell technology, and particularly relates to a thermal shock resistant perovskite solar cell and its preparation method. Background Technology

[0002] Since the Industrial Revolution, fossil fuels have been a crucial driver of socio-economic development. However, fossil fuels are non-renewable energy sources; their reserves are finite, and extraction rates far exceed their formation rates, inevitably leading to depletion. To reduce dependence on fossil fuels and achieve sustainable development, the development of clean and efficient renewable energy sources is urgently needed. Solar energy, as a clean and sustainable energy source, is considered one of the important ways to solve the energy crisis and environmental pollution problems. Unlike the geographically concentrated distribution of fossil resources such as oil or natural gas, solar energy can be obtained almost globally. This widespread distribution makes solar energy highly universal, capable of meeting the energy needs of different regions.

[0003] In recent years, solar cell technology has developed rapidly. From traditional crystalline silicon solar cells to emerging thin-film batteries, researchers are constantly seeking breakthroughs to improve energy conversion efficiency, reduce manufacturing costs, and expand the practical applications of the technology. Against this backdrop, perovskite solar cells have become a research hotspot due to their excellent photoelectric performance, low-cost fabrication processes, and abundant raw materials. The core material of perovskite solar cells is an organic-inorganic hybrid perovskite with an ABX3 structure, where the A-site is typically a large-radius monovalent organic cation (such as MA). + or FA + ) or inorganic cations (such as Cs) + The B site is occupied by a divalent metal cation (such as Pb). 2+ or Sn 2+ The X-position is occupied by a halide anion (such as I). - or Br - Due to its low exciton binding energy, long carrier lifetime and diffusion length, dual carrier transport characteristics, high absorption coefficient in the visible and near-infrared regions, and high defect tolerance, the photoelectric conversion efficiency of perovskite solar cells has rapidly increased from the initial 3.8% to 27.3% in just over a decade, approaching the level of traditional silicon-based solar cells.

[0004] However, during device operation, external thermal stress, light exposure, and other interferences accumulate and propagate at the buried interface, leading to structural instability of the perovskite layer. Since the buried interface is difficult to repair in the future, it ultimately results in poor film morphology, impaired charge transport properties, and low photoelectric conversion efficiency and poor stability of perovskite solar cells. Summary of the Invention The present invention provides a method for enhancing the interface stability of perovskite solar cells by introducing FPI molecules containing flexible alkyl chains between the perovskite layer and the electron transport layer. By regulating the stress at the interface and suppressing the generation of thin film phase separation, the device efficiency and stability are significantly improved.

[0005] The first aspect of this application provides a thermal shock resistant perovskite solar cell, comprising a transparent conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer and an electrode layer sequentially connected along a predetermined direction, wherein an FPI interface modification layer is introduced between the perovskite layer and the electron transport layer.

[0006] A molecule with a flexible alkyl chain (such as FPI) is introduced at the interface between the electron transport layer and the perovskite layer. The FPI molecule is a fluoroiodine quaternary ammonium salt, anchored to titanium dioxide at its lower end via hydrogen bonds, and interacting with the perovskite at its upper end via F ions. A flexible alkyl chain connects them in the middle, ensuring both carrier transport performance and flexibility. Most commercially available materials are P-type insertion materials, but this patent uses an N-type material, which modulates the titanium dioxide electron transport layer, aligning with the structural optimization expectations of this application. Simultaneously, by utilizing its ability to release the high stress buildup between the electron transport layer and the perovskite layer, phase separation and defect passivation are suppressed, improving the long-term stability of the perovskite solar cell. The described perovskite solar cell structure consists of a glass substrate, an FTO transparent electrode, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a metal electrode connected sequentially.

[0007] In any embodiment, the transparent conductive glass is fluorine-doped tin oxide (FTO) conductive glass with a resistance of 12 Ωsq. -1 .

[0008] In any embodiment, the electron transport layer has a thickness of 20nm-80nm and is made of TiO2.

[0009] In any embodiment, the FPI interface modification layer is in the form of a thin film with a thickness of 1nm-10nm.

[0010] In any embodiment, the perovskite layer is a thin film with a thickness of 400 nm-800 nm, has an ABX3 crystal structure, and the A-site includes MA. + FA + Cs + At least one of them, with the B site being Pb 2+ X is I - , Br - Cl - At least one of them.

[0011] In any embodiment, the hole transport layer is a thin film with a thickness of 10 nm-60 nm, and the material used is 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene (Spiro-MeOTAD). In any embodiment, the electrode layer material is a metal material with high conductivity commonly used in perovskite solar cells, including gold, silver, copper, and molybdenum, and the electrode layer thickness is 50nm-150nm.

[0012] The second aspect of this application provides a method for fabricating a thermally shock-resistant perovskite solar cell, comprising the following steps: (1) Clean the FTO conductive glass; (2) Chemical bath deposition of TiO2 electron transport layer; (3) Preparation of FPI passivation layer: FPI solution is dropped onto the surface of TiO2 electron transport layer and spin-coated. After spin-coating, the layer is placed on a hot table at 100-120℃ and heated for 10-20 minutes to ensure complete evaporation of solvent. After cooling, ozone treatment is performed. (4) Preparation of perovskite thin film: The perovskite precursor solution is dropped onto the FPI passivation layer and spin-coated; 1 ml of diethyl ether is quickly added as an anti-solvent 10-14 s before the end of spin-coating; the perovskite thin film after spin-coating is pre-annealed at 90-110℃ for about 1-2 minutes to avoid the formation of excessively large or unevenly distributed grains due to rapid evaporation of solvent during the final annealing, thereby reducing pinholes and defects, until the film color turns black; finally, the pre-annealed perovskite thin film is annealed on a hot stage at 150℃ for 15-20 minutes to ensure that the solvent is completely evaporated and a perovskite layer is formed. (5) Hole transport layer preparation: 15 μL of Spiro-OMeTAD solution was added to the perovskite layer and spin-coated to obtain the hole transport layer; (6) Metal electrode preparation: A gold electrode is deposited on the hole transport layer using a vacuum evaporation coating apparatus.

[0013] Using deionized water as the passivation layer solvent, FPI solutions of different concentrations were prepared. The synthesized FPI reagent was weighed according to the concentration and placed into ampoules, followed by the addition of deionized water. The mixture was stirred for at least 4 hours to obtain a uniformly dissolved FPI solution. 50 μl of the FPI solution was dropped onto the surface of a TiO2 substrate and spin-coated at 5000 rpm for 30 seconds. After spin-coating, the substrate was heated on a hot table at 110°C for 15 minutes. After cooling, the FPI passivation layer was obtained.

[0014] Various passivation materials containing flexible alkyl chain molecular structures were screened, and carnitine hydrochloride was ultimately selected as the most suitable material for the existing perovskite formulation. Using deionized water as the passivation layer solvent, carnitine hydrochloride solutions of different concentrations were prepared. Purchased carnitine hydrochloride was weighed according to concentration and placed in ampoules, followed by the addition of deionized water. The mixture was stirred for at least 4 hours to obtain a uniformly dissolved carnitine hydrochloride solution. 50 μl of the carnitine hydrochloride solution was dropped onto the surface of the TiO2 electron transport layer and spin-coated at 5000 rpm for 30 seconds. After spin-coating, the layer was heated on a 110°C hot plate for 15 minutes. After cooling, the carnitine hydrochloride passivation layer was obtained.

[0015] In any embodiment, the concentration of the FPI solution is 7 mg / ml, and the amount of FPI solution added is 40-80 μL.

[0016] In any embodiment, the perovskite precursor solution is prepared by dissolving 0.885 mmol of FAI, 0.075 mmol of MAI, 0.05 mmol of CsI and 1.01 mmol of PbI2 in a mixed solvent of 840 μl of DMF and 160 μl of DMSO, stirring for more than 4 hours, and then filtering for later use.

[0017] In any embodiment, the preparation of the Spiro-OMeTAD solution is as follows: 70-80 mg of Spiro-OMeTAD is dissolved in 1 mL of chlorobenzene, and then 20-30 μl of tert-butylpyridine and 15-20 μl of lithium-(trifluoromethanesulfonyl)imide (520 mg / mL) are added as additives to the Spiro-OMeTAD solution and stirred for more than 4 hours. After filtration, the solution is ready for use.

[0018] In any embodiment, the water bath temperature in step (2) is 80-90℃ and the water bath time is 30-50 minutes.

[0019] In any embodiment, step (3) involves spin coating at a speed of 3000-5000 rpm for 30 seconds.

[0020] In any embodiment, step (4) involves spin coating at a low speed of 1000 rpm for 4 seconds followed by spin coating at a high speed of 5000 rpm for 20 seconds.

[0021] In any embodiment, the spin coating speed in step (5) is 3000-5000 rpm and the spin coating time is 20-30 s.

[0022] In any embodiment, the thickness of the metal electrode is 50-150 nm.

[0023] The beneficial effects of this application are: The perovskite solar cell, from bottom to top, consists of: an FTO transparent glass conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a Spiro-OMeTAD hole transport layer, and a metal electrode layer. The FPI molecular passivation layer introduced using this method is anchored at the TiO2-perovskite interface with a unique "molecular bridge" structure. The introduction of FPI has three main effects on the interface stability of the perovskite solar cell: 1. The introduction of FPI significantly reduces the modulus difference between the perovskite layer and the electron transport layer, significantly promoting the release of interfacial stress and reducing the interfacial thermally induced stress energy. 2. The introduction of FPI suppresses the occurrence of phase separation in the perovskite film and inhibits the formation of degradation products. 3. The introduction of FPI promotes the vertical growth of perovskite film grains and improves carrier transport efficiency. Perovskite solar cells with this passivation layer exhibit higher photoelectric conversion efficiency and good long-term stability. The perovskite solar cells prepared using this method are characterized by simple process, excellent stability, and good repeatability, making them suitable for large-scale application and showing great promise for future use.

[0024] This invention introduces a fiber optic interface (FPI) stress control layer between the perovskite layer and the electron transport layer. Utilizing the "flexibility" of long alkyl chains, the FPI connects the perovskite and electron transport layers as "bridge molecules." The F ions on the FPI interact with the perovskite film, suppressing lead iodide formation. Simultaneously, the FPI reduces the surface roughness of the electron transport layer, promoting the orderly growth of subsequent perovskite crystals. The FPI interface control layer can also regulate the significant interfacial modulus difference between the perovskite and titanium oxide layers. During heating, the large amount of thermal stress accumulated at the interface can be effectively released, mitigating the negative effects of thermal stress accumulation, such as cracking. Furthermore, the FPI has a significant effect on phase separation in the perovskite film, exhibiting a significant inhibitory effect on phase separation in perovskite devices with different band gaps. In addition, the addition of FPI material promotes vertical grain growth, thereby significantly improving the long-term stability and device efficiency of perovskite solar cells. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the perovskite solar cell structure of this application; Figure 2 This is a statistical graph of the photoelectric conversion efficiency of perovskite solar cells prepared in Comparative Example 1 and when the FPI solution concentration of this application is 7 mg / ml. Figure 3 These are morphology images of the perovskite bottom interface when the concentration of FPI solution in Comparative Example 1 and this application is 7 mg / ml; Figure 4 This is a statistical chart of the photoelectric conversion efficiency of perovskite solar cells prepared with FPI solutions of different concentrations according to this application.

[0026] Figure 5 This is a statistical graph of the photoelectric conversion efficiency of perovskite solar cells prepared with different concentrations of carnitine hydrochloride solutions according to this application; Figure 6 The images show the phase separation of the perovskite thin film in Comparative Example 1 and the present application when the FPI solution concentration is 7 mg / ml. Detailed Implementation

[0027] Except for FPI, all raw materials used in this invention are commercially available chemically pure reagents. The invention will be further described in detail below with reference to specific embodiments. Without departing from the spirit of this invention, it should not be limited to the specific content described in the following embodiments.

[0028] However, during device operation, external thermal stress, light exposure, and other disturbances typically act first on the buried interface, accumulating and propagating, further exacerbating the structural instability of the perovskite layer. Worse still, because the buried interface forms in the early stages of thin film fabrication, it is difficult to effectively repair in subsequent processes. Therefore, this interface often becomes a core region for defect enrichment, stress concentration, and preferential decomposition reactions. During perovskite crystallization and subsequent thermal cycling, the thermal expansion mismatch between the perovskite layer and the underlying transport layer generates enormous interfacial stress at the buried interface during the initial crystallization stage. This induces harmful microstructural defects at the buried interface, including microcracks, voids, and localized strain concentration zones. More critically, this thermomechanical stress disrupts perovskite nucleation kinetics, hinders the formation of an ordered lattice, leads to poor film morphology, impaired charge transport properties, and accelerates degradation pathways under operating conditions.

[0029] By introducing flexible alkyl chains into the perovskite and oxide electron transport layers, a unique "molecular bridge" structure is anchored at the TiO2-perovskite interface. This soft interface generates extremely low modulus and reduces interfacial stress energy, thereby suppressing defect formation and minimizing phase separation. Simultaneously, the functional groups in the FPI passivate defects, inducing vertically oriented perovskite crystallization, resulting in a dense film with fewer pores and improved structural uniformity. Perovskite solar cells equipped with this passivation layer exhibit high photoelectric conversion efficiency and good long-term stability. Example 1 This invention utilizes deionized water as the passivation layer solvent to prepare FPI solutions of different concentrations. The synthesized FPI reagent is weighed according to its concentration and placed into ampoules, followed by the addition of deionized water. The mixture is stirred for at least 4 hours to obtain a uniformly dissolved FPI solution. The prepared FPI solution is then spin-coated onto the prepared TiO2 electron transport layer and annealed at 110°C for 15 minutes to obtain the FPI passivation layer.

[0030] The specific steps for preparing FPI solutions of different concentrations according to this invention are as follows: FPI solution preparation: Prepare FPI solutions at concentrations of 3, 7, and 11 mg / ml, place them on a magnetic stirrer and stir for more than 4 hours to ensure that the FPI is fully dissolved, and then filter to obtain the FPI spin-coating solution.

[0031] The perovskite solar cell assembled according to this invention is assembled in the following steps: (1) Clean the 1.8*1.2 cm FTO conductive glass substrate. Clean the FTO conductive glass substrate with acetone, deionized water and ethanol in sequence by ultrasonic cleaning for 30 minutes each time. Dry it with nitrogen to remove the stains on the surface of the FTO conductive glass substrate and obtain a clean FTO conductive glass substrate. Then treat it with ozone for 15 minutes under the UV lamp of the ultraviolet ozone treatment machine.

[0032] (2) Chemical bath deposition of TiO2 electron transport layer: Using a 1000 μl pipette, 3.3 ml of TiCl4 solution was slowly added to 150 ml of deionized water in four portions, stirring continuously until homogeneous. During the water bath deposition process, the water bath was heated to 90°C and maintained for 50 minutes. After deposition, the prepared TiO2 substrate was rinsed sequentially with deionized water and anhydrous ethanol. Subsequently, the rinsed TiO2 substrate was dried with a nitrogen gun and treated with ozone for 15 minutes.

[0033] (3) Preparation of FPI passivation layer: 50 μl of FPI solution was dropped onto the surface of TiO2 substrate and spin-coated at 5000 rpm for 30 s. After spin-coating, the substrate was placed on a hot table at 110°C for 15 minutes and then cooled and treated with ozone for 15 minutes.

[0034] (4) The perovskite thin film was prepared using a one-step anti-solvent method. The perovskite precursor solution was spin-coated at a low speed of 1000 rpm for 4 seconds, followed by a high speed of 5000 rpm for 20 seconds. 1 ml of diethyl ether was rapidly added as an anti-solvent 12 seconds before the end of the spin-coating. After spin-coating, the perovskite thin film was pre-annealed at 90°C for about 1 minute until the film turned black. Finally, the pre-annealed perovskite thin film was annealed on a hot plate at 150°C for 15 minutes. After cooling, it was removed for later use.

[0035] (5) Spin-coat the prepared Spiro-OMeTAD solution onto the prepared perovskite film at a spin speed of 5000 rpm for 30 s.

[0036] (6) Gold electrodes are prepared on the surface of the prepared device by vacuum evaporation at a vacuum degree of 10. -4 At a deposition rate of 1.0 Å / s, a gold electrode with a thickness of approximately 100 nm was obtained.

[0037] At this point, the assembly of this perovskite solar cell with a flexible alkyl chain FPI passivation layer is complete.

[0038] By introducing an FPI passivation layer at the interface between the electron transport layer and the perovskite layer, the molecule can be firmly anchored to the surface of the TiO2 electron transport layer, increasing the surface smoothness of the TiO2 electron transport layer. Simultaneously, it bridges the modulus difference between the perovskite layer and the TiO2 electron transport layer, allowing it to function long-term at the buried interface and improving the long-term stability of the perovskite solar cell. The perovskite solar cell prepared using this method possesses advantages such as low cost, high carrier transport efficiency, high photoelectric conversion efficiency, and low interfacial stress energy, meeting the development requirements for long-term stability of perovskite solar cells under both light and thermal conditions.

[0039] Example 2 This invention tested the addition of another passivation material containing flexible alkyl chains (carnitine hydrochloride) between the perovskite layer and the electron transport layer. Using deionized water as the passivation layer solvent, carnitine hydrochloride solutions of different concentrations were prepared. Purchased carnitine hydrochloride was weighed according to concentration and placed in ampoules, followed by the addition of deionized water. The mixture was stirred for at least 4 hours to obtain a uniformly dissolved carnitine hydrochloride solution. The prepared carnitine hydrochloride solution was then spin-coated onto the prepared TiO2 electron transport layer and annealed at 110°C for 15 minutes to obtain the carnitine hydrochloride passivation layer.

[0040] The specific steps for preparing carnitine hydrochloride solutions of different concentrations according to this invention are as follows: Preparation of carnitine hydrochloride solution: Prepare carnitine hydrochloride solutions at concentrations of 0, 1, and 2 mg / ml, and stir on a magnetic stirrer for more than 4 hours to ensure that the carnitine hydrochloride is fully dissolved. After filtration, the carnitine hydrochloride spin coating solution is obtained.

[0041] The perovskite solar cell assembled according to this invention is assembled in the following steps: (1) Clean the 1.8*1.2 cm FTO conductive glass substrate. Clean the FTO conductive glass substrate with acetone, deionized water and ethanol in sequence by ultrasonic cleaning for 30 minutes each time. Dry it with nitrogen to remove the stains on the surface of the FTO conductive glass substrate and obtain a clean FTO conductive glass substrate. Then treat it with ozone for 15 minutes under the UV lamp of the ultraviolet ozone treatment machine.

[0042] (2) Chemical bath deposition of TiO2 electron transport layer: Using a 1000 μl pipette, 3.3 ml of TiCl4 solution was slowly added to 150 ml of deionized water in four portions, stirring continuously until homogeneous. During the water bath deposition process, the water bath was heated to 90°C and maintained for 50 minutes. After deposition, the prepared TiO2 substrate was rinsed sequentially with deionized water and anhydrous ethanol. Subsequently, the rinsed TiO2 substrate was dried with a nitrogen gun and treated with ozone for 15 minutes.

[0043] (3) Preparation of carnitine hydrochloride passivation layer: 50 μl of carnitine hydrochloride solution was dropped onto the surface of TiO2 substrate and spin-coated at 5000 rpm for 30 s. After spin-coating, the substrate was placed on a hot table at 110°C for 15 minutes and then cooled and treated with ozone for 15 minutes.

[0044] (4) The perovskite thin film was prepared using a one-step anti-solvent method. The perovskite precursor solution was spin-coated at a low speed of 1000 rpm for 4 seconds, followed by a high speed of 5000 rpm for 20 seconds. 1 ml of diethyl ether was rapidly added as an anti-solvent 12 seconds before the end of the spin-coating. After spin-coating, the perovskite thin film was pre-annealed at 90°C for about 1 minute until the film turned black. Finally, the pre-annealed perovskite thin film was annealed on a hot plate at 150°C for 15 minutes. After cooling, it was removed for later use.

[0045] (5) Spin-coat the prepared Spiro-OMeTAD solution onto the prepared perovskite film at a spin speed of 5000 rpm for 30 s.

[0046] (6) Gold electrodes are prepared on the surface of the prepared device by vacuum evaporation at a vacuum degree of 10. -4 At a deposition rate of 1.0 Å / s, a gold electrode with a thickness of approximately 100 nm was obtained.

[0047] At this point, the perovskite solar cell with a carnitine hydrochloride passivation layer is assembled.

[0048] By introducing a carnitine hydrochloride passivation layer at the interface between the electron transport layer and the perovskite layer, tests including photoelectric conversion efficiency and stress simulations revealed a reduction in interfacial stress. We hypothesize that the flexible alkyl chain molecular structure may play a role in releasing interfacial stress in perovskite solar cells. The perovskite solar cells with the added carnitine hydrochloride passivation layer also exhibited higher photoelectric conversion efficiency and stronger long-term stability compared to the control group.

[0049] Comparative Example 1 Comparative Example 1 removed step (3) from Example 1 to obtain a test thin film and perovskite solar cell without an FPI layer.

[0050] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A thermal shock resistant perovskite solar cell, characterized in that, It includes a transparent conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer and an electrode layer connected sequentially along a set direction, with an FPI interface modification layer introduced between the perovskite layer and the electron transport layer.

2. The thermal shock resistant perovskite solar cell according to claim 1, characterized in that, The transparent conductive glass is fluorine-doped tin oxide conductive glass with a resistance of 12Ω sq. -1 The electron transport layer has a thickness of 20nm-80nm and is made of TiO2. The FPI interface modification layer is a thin film with a thickness of 1nm-10nm.

3. The thermal shock resistant perovskite solar cell according to claim 1, characterized in that, The perovskite layer is a thin film with a thickness of 400nm-800nm, and has an ABX3 crystal structure, with A-sites including MA. + FA + Cs + At least one of them, with the B site being Pb 2+ X is I - , Br - Cl - At least one of the following: the hole transport layer is in the form of a thin film with a thickness of 10nm-60nm, and the material used is 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene (Spiro-MeOTAD); the electrode layer material includes gold, silver, copper, and molybdenum, and the electrode layer thickness is 50nm-150nm.

4. A method for preparing a thermally shock resistant perovskite solar cell, characterized in that, Includes the following steps: (1) Clean the FTO conductive glass; (2) Chemical bath deposition of TiO2 electron transport layer; (3) Preparation of FPI passivation layer: FPI solution is dropped onto the surface of TiO2 electron transport layer, spin-coated, and after spin-coating, it is placed on a hot table at 100-120℃ and heated for 10-20 minutes until the solvent is completely evaporated. After cooling, ozone treatment is performed. (4) Preparation of perovskite thin film: The perovskite precursor solution is dropped onto the FPI passivation layer and spin-coated; 1 ml of diethyl ether is quickly added as an anti-solvent 10-14 s before the end of spin-coating; the perovskite thin film after spin-coating is pre-annealed at 90-110℃ for about 1-2 minutes until the film turns black; finally, the pre-annealed perovskite thin film is annealed on a hot plate at 150℃ for 15-20 minutes until the solvent is completely evaporated and a perovskite layer is formed. (5) Hole transport layer preparation: 15 μL of Spiro-OMeTAD solution was added to the perovskite layer and spin-coated to obtain the hole transport layer; (6) Metal electrode preparation: A gold electrode is deposited on the hole transport layer using a vacuum evaporation coating apparatus.

5. The method for preparing a thermally shock-resistant perovskite solar cell according to claim 4, characterized in that, The concentration of the FPI solution is 7 mg / ml, and the amount of FPI solution added is 40-80 μL.

6. The method for preparing a thermally shock-resistant perovskite solar cell according to claim 4, characterized in that, Preparation of the perovskite precursor solution: Dissolve 0.885 mmol of FAI, 0.075 mmol of MAI, 0.05 mmol of CsI and 1.01 mmol of PbI2 in a mixed solvent of 840 μl of DMF and 160 μl of DMSO, stir for more than 4 hours, filter and set aside.

7. The method for preparing a thermally shock-resistant perovskite solar cell according to claim 4, characterized in that, Preparation of the Spiro-OMeTAD solution: Dissolve 70-80 mg of Spiro-OMeTAD in 1 mL of chlorobenzene, then add 20-30 μl of tert-butylpyridine and 15-20 μl of lithium-(trifluoromethanesulfonyl)imide (520 mg / mL) as additives to the Spiro-OMeTAD solution and stir for more than 4 hours. Filter and set aside.

8. The method for preparing a thermally shock-resistant perovskite solar cell according to claim 4, characterized in that, In step (2), the water bath temperature is 80-90℃ and the water bath time is 30-50 minutes; in step (3), spin coating is performed at a speed of 3000-5000 rpm for 30 seconds.

9. The method for preparing a thermally shock-resistant perovskite solar cell according to claim 4, characterized in that, In step (4), spin coating is performed at a low speed of 1000 rpm for 4 seconds, and then at a high speed of 5000 rpm for 20 seconds; in step (5), the spin coating speed is 3000-5000 rpm and the spin coating time is 20-30 seconds.

10. The method for preparing a thermally shock-resistant perovskite solar cell according to claim 4, characterized in that, The thickness of the metal electrode is 50-150 nm.

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