Method for realizing interface welding of perovskite solar cell by self-repairing polymer

Abstract

A method for realizing interface of perovskite solar cell by self-repairing polymer, a catalyst and a tin oxide aqueous solution are mixed, coated on an ITO transparent substrate to form a SnO2-based electron transport layer; a ternary cation perovskite solution is modified by a benzoxazine derivative, and is spin-coated on the surface of the SnO2-based electron transport layer according to a set process, and a film for welding the interface of the SnO2-based electron transport layer and the perovskite layer is obtained through annealing. The self-repairing polymer is obtained by ring-opening reaction of the benzoxazine derivative in the perovskite layer under the action of the catalyst in the SnO2 layer. The perovskite solar cell is welded by the self-repairing polymer to realize dynamic elimination of the interface, accelerate charge transport and extraction, has reversible bonds, in-situ thermal repair of crystal surface and grain boundary defects, regulates nucleation and crystallization of the perovskite, and improves the crystallization quality of the film. The method is simple in operation, low in cost and easy for large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of perovskite solar cell technology and relates to a method for achieving interface welding of perovskite solar cells using a self-healing polymer. Background Technology

[0002] Perovskite solar cells, as typical new energy devices, are considered highly likely for large-scale industrialization due to their low cost, solution-processability, ease of flexible substrate deposition, and excellent photoelectric performance. Currently, the certified energy conversion efficiency (25.7%) of perovskite solar cells is comparable to that of commercial silicon-based solar cells, but their lifespan still lags behind. High-efficiency and stable devices are not only related to the quality of the perovskite thin film but also to interface engineering (CN113299833B). The lower interface layer material has a positive impact on the quality of the perovskite thin film; microscopically, it can control the nucleation, crystallization, and growth of the perovskite film, while macroscopically, it can improve the uniformity of perovskite layer coverage and optimize interface contact.

[0003] To improve interfacial charge transport and perovskite film quality, researchers have employed strategies such as barium titanate interface modification (CN107946464B), ionic liquid-modified dual-interface (CN114975790A), and ammonium formate treatment at the buried interface (CN114695667A). These strategies have achieved certain results in suppressing nonradiative recombination at the interface, passivating surface grain boundary defects, and improving the morphology of perovskite films. However, the presence of the interface layer still limits the improvement of photoelectric conversion efficiency and stability of perovskite solar cells.

[0004] Seok et al. (SI Seok, et al., Nature, 2021, Vol. 598, p444-450) used Cl-bonded SnO2 to couple with Cl-containing perovskite precursors to form a coherent interface layer between the electron transport layer and the perovskite layer. Although this accelerated charge extraction and improved the photoelectric conversion efficiency of perovskite solar cells, the stability issues such as nucleation control of the perovskite layer and crystal plane fracture caused by residual stress have not yet been resolved, which restricts the industrialization of perovskite solar cells.

[0005] Jiang et al. (Angew. Chem. Int. Ed. 2020, Vol. 59, p16602-16608) designed a self-healing pyridine-based polymer to be introduced into perovskite thin films, which can improve the self-healing ability of grain boundary fatigue cracks. However, this is also an interface modification strategy and does not eliminate the interface. Therefore, developing a perovskite solar cell that is relatively inexpensive, easy to repair grain boundary defects, and dynamically eliminates interfaces is a key research focus. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for interface welding of perovskite solar cells using self-healing polymers.

[0007] This invention is achieved through the following technical solutions.

[0008] The present invention discloses a method for interface welding of perovskite solar cells using a self-healing polymer, comprising the following steps.

[0009] (1) Mix the catalyst aqueous solution with the tin oxide aqueous solution at 15~30℃ (V SnO2 :V H2O The catalyst and tin oxide were spin-coated at 3000 rpm onto a dry ITO transparent substrate at a mass ratio of 1:3 (0.01~0.5:100) for 30 seconds. The substrate was then annealed in air at 150°C for 30 minutes to form a SnO2-based electron transport layer.

[0010] (2) The benzoxazine derivative is dispersed in an organic solvent, and the mass ratio of the benzoxazine derivative to the ternary cation perovskite solution is 0.01~0.5:1. The mixture is stirred at 600~900 rpm for 1~4 h to form a uniform modified perovskite solution.

[0011] (3) In an N2 glove box, spin-coat the solution described in step (2) onto the surface of the SnO2-based electron transport layer described in step (1). Spin-coating is performed in two stages. In the first stage, the rotation speed is 500-1000 rpm, the duration is 6-10 s, and the acceleration is 100-500 rpm. In the second stage, the rotation speed is 5000 rpm, the duration is 25-30 s, and the acceleration is 1000 rpm. At the 5th to 10th s from the end, the antisolvent is added dropwise. Then, the mixture is annealed at 150℃ for 10-30 min to obtain a perovskite film with a self-healing polymer welded interface between the SnO2-based electron transport layer and the perovskite layer.

[0012] (4) When the perovskite film described in step (3) is cooled to 25°C, a spiro-based hole transport layer material is deposited on its surface. The spin coating speed is 4000 ~ 5000 rpm and the duration is 30 s.

[0013] (5) Finally, a 100 nm metal electrode was deposited under vacuum conditions to obtain a perovskite solar cell.

[0014] The catalyst mentioned in step (1) of this invention is one of p-toluenesulfonic acid, imidazole or cyclohexyl-p-toluenesulfonic acid, and the mass concentration of the aqueous solution of the catalyst is 1~5 mg / mL.

[0015] The benzoxazine derivative described in step (2) of this invention has the following general structural formula: ;

[0016] Where R1 = CH2, or etc.; R2 = H, Cl or Br, etc.; n = 1~10.

[0017] The organic solvent is one or two of ultra-dry chloroform, N,N-dimethylformamide (DMF), N-methylpyrrolidone or dimethyl sulfoxide (DMSO), and the mass concentration of the benzoxazine derivative in the organic solvent is 5~20 mg / mL.

[0018] The molecular formula of the ternary cationic perovskite is Cs. 0.05 FA 0.85 MA 0.10 Pb(I 0.97 Br 0.03 3; The ternary cation perovskite solution is obtained by dissolving CsI, MACl, MABr, FAI, and PbI2 in a mixed solvent of DMF and DMSO, with a volume ratio of DMF to DMSO of 4:1; The mass concentrations of CsI, MACl, MABr, FAI, and PbI2 are 19.80 mg / mL, 13.53 mg / mL, 16.20 mg / mL, 224.40 mg / mL, and 742.20 mg / mL, respectively.

[0019] The antisolvent mentioned in step (3) of the present invention is chlorobenzene, or chlorobenzene containing benzoxazine derivatives, with a mass concentration of 0.01~1 mg / mL.

[0020] Self-healing polymers are polymers obtained by ring-opening reactions of benzoxazine derivatives in the perovskite layer under the catalysis of the SnO2 layer. Their general structural formula is as follows: ;

[0021] In the formula, m = 42 ~ 100.

[0022] The average molecular weight of the self-healing polymer is 10178~43658.

[0023] The perovskite solar cell interface welding described in this invention involves a catalyst in the SnO2-based electron transport layer that promotes a ring-opening reaction of benzoxazine derivatives in the ternary cationic perovskite to form a self-healing polymer. The atoms or characteristic groups in the self-healing polymer can both chemically interact with the perovskite layer and interact with the SnO2-based electron transport layer. The self-healing polymer plays a role in chemically welding the interface between the SnO2-based electron transport layer and the perovskite layer.

[0024] The advantages of this invention compared to existing technologies are as follows: This invention prepares a self-healing polymer by introducing a benzoxazine derivative at the SnO2-based electron transport layer / perovskite layer interface via a ring-opening reaction, achieving interface welding, dynamically eliminating the interface, and accelerating charge transport and extraction; it possesses reversible bonds, enabling in-situ thermal repair of crystallographic defects; and it regulates the nucleation and crystallization of perovskite, improving the crystal quality of the thin film. The method is simple to operate, low in cost, and easy to scale up for production. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a perovskite solar cell module fabricated using a self-healing polymer welding interface method according to the present invention. In the diagram, 1 is an ITO transparent substrate; 2 is a SnO2-based electron transport layer; 3 is a self-healing polymer; 4 is a perovskite layer; 5 is a Spiro-based hole transport layer; and 6 is an Ag electrode.

[0026] Figure 2 This is a schematic diagram illustrating the principle of using the self-healing polymer to achieve interface welding in perovskite solar cells according to the present invention. Specifically, 3. The hydroxyl groups in the self-healing polymer form hydrogen bonds with the hydroxyl groups in 2. The N and O atoms containing lone electrons in the self-healing polymer form coordination bonds with the lead ions in 4. The self-healing polymer acts as a chemical welder between 2. The SnO2-based electron transport layer and 4. The perovskite layer.

[0027] Figure 3 Photographs showing the thermal repair properties of the α,ω-dichlorobenzoxazine-poly(dimethylsiloxane) ring-opening polymer. In the images: a) polymer broken at room temperature; b) polymer fused together after being heated to 113.5℃; c) polymer broken again after cooling to room temperature; d) polymer fused together again after being heated to 114.4℃.

[0028] Figure 4 The JV performance test curves are for the perovskite solar cell modules obtained in the reference and Example 1. Implementation

[0029] The present invention will be further described in detail through the following embodiments.

[0030] Unless otherwise specified, all reagents used in the embodiments can be purchased from the market.

[0031] Comparative examples: Preparation of reference perovskite thin films and battery modules.

[0032] Tin oxide aqueous solution (V) SnO2 :V H2O A 1:3 ratio of DMF and DMSO was spin-coated onto a dry ITO transparent substrate at 3000 rpm for 30 s, followed by annealing in air at 150°C for 30 min to form a SnO2-based electron transport layer. A ternary cation perovskite solution was prepared by dissolving 19.80 mg CsI, 13.53 mg MACl, 16.20 mg MABr, 224.40 mg FAI, and 742.20 mg PbI2 in 1 mL of a 4:1 DMF / DMSO mixture. In an N2 glove box, the reference perovskite solution was spin-coated onto the SnO2-based electron transport layer surface in two stages: the first stage was at 1000 rpm with an acceleration of 200 rpm for 10 s, and the second stage was at 5000 rpm with an acceleration of 1000 rpm for 30 s. The spin-coating was completed on the 10th s from the end of the spin-coating process. Chlorobenzene was added dropwise at s, and then annealed at 150℃ for 10 min to obtain a reference perovskite film. When the perovskite film was cooled to 25℃, a spiro-based hole transport layer material was deposited on its surface at 4500 rpm for 30 s spin coating. Finally, a 100 nm thick metal electrode was deposited under vacuum to obtain a reference perovskite solar cell.

[0033] Example 1

[0034] The preparation of benzoxazine derivatives, taking α,ω-dichlorobenzoxazine-poly(dimethylsiloxane) as an example.

[0035] (3-aminopropyl)-terminated polydimethylsiloxane (1.25 g, 0.5 mM), p-chlorophenol (128.5 mg, 1 mM), and paraformaldehyde (0.24 g, 8 mM) were dissolved in 60 mL of chloroform in a three-necked flask. The mixture was refluxed under N2 protection for 24 h. Solid impurities were removed by vacuum filtration, and the filtrate was rotary evaporated to remove all chloroform. The filtrate was then purified by nanofiltration and vacuum dried at room temperature for 12 h to obtain oily α,ω-dichlorobenzoxazine-poly(dimethylsiloxane).

[0036] Example 2

[0037] A 2 mg / mL aqueous solution of p-toluenesulfonic acid was reacted with an aqueous solution of tin oxide (V) at 15°C. SnO2 :V H2OA homogeneous aqueous solution with a mass ratio of 0.3:100 was formed by mixing α,ω-dichlorobenzoxazine-poly(dimethylsiloxane) at a ratio of 1:3. This solution was then spin-coated onto a dry ITO transparent substrate at 3000 rpm for 30 seconds and annealed in air at 150°C for 30 minutes to form a SnO2-based electron transport layer. A self-made α,ω-dichlorobenzoxazine-poly(dimethylsiloxane) was dispersed in DMF with a mass concentration of 19.80 mg CsI, 13.53 mg MACl, 16.20 mg MABr, 224.40 mg FAI, and 742.20 mg PbI2. This solution was dissolved in 1 mL of a 4:1 mixture of DMF and DMSO to prepare a ternary cationic perovskite solution. The mass ratio of α,ω-dichlorobenzoxazine-poly(dimethylsiloxane) to the perovskite solution was 0.3:1. The solution was mixed at 900 rpm. A uniform modified perovskite solution was formed. In an N2 glove box, the uniform modified perovskite solution was spin-coated onto the surface of a SnO2-based electron transport layer. The spin-coating was performed in two stages: the first stage had a rotation speed of 1000 rpm, an acceleration of 200 rpm, and a duration of 10 s; the second stage had a rotation speed of 5000 rpm, an acceleration of 1000 rpm, and a duration of 30 s. Chlorobenzene was added dropwise at the 10th second before the end of the spin-coating. The mixture was annealed at 150℃ for 20 min. α,ω-dichlorobenzoxazine-poly(dimethylsiloxane) underwent ring-opening polymerization catalyzed by p-toluenesulfonic acid to obtain a self-healing polymer with an average molecular weight of 16047, which welded the interface between the SnO2-based electron transport layer and the perovskite layer. When the perovskite film cooled to 25℃, a spiro-based hole transport layer material was deposited on its surface at a rotation speed of 4500 rpm for 30 seconds. Finally, a 100 nm thick metal electrode was deposited under vacuum conditions to obtain a perovskite solar cell.

[0038] Example 3

[0039] A 5 mg / mL imidazole aqueous solution was reacted with a tin oxide aqueous solution (V) at 30°C. SnO2 :V H2OA homogeneous aqueous solution with a mass ratio of 0.5:100 was formed by mixing α,ω-dibenzoxazine-poly(ethylene glycol) at a ratio of 1:3 and spin-coating it onto a dry ITO transparent substrate at 3000 rpm for 30 s. The substrate was then annealed in air at 150°C for 30 min to form a SnO2-based electron transport layer. A self-made α,ω-dibenzoxazine-poly(ethylene glycol) was dispersed in N,N-dimethylformamide and dimethyl sulfoxide at a volume ratio of 4:1, with a mass concentration of 5 mg / mL. 19.80 mg CsI, 13.53 mg MACl, 16.20 mg MABr, 224.40 mg FAI, and 742.20 mg PbI2 were dissolved in 1 mL of a 4:1 mixture of DMF and DMSO to prepare a ternary cationic perovskite solution. The mass ratio of α,ω-dibenzoxazine-poly(ethylene glycol) to the perovskite solution was 0.5:1. The mixture was stirred at 600 rpm for 4 minutes. A uniform modified perovskite solution was formed. In an N2 glove box, the uniform modified perovskite solution was spin-coated onto the surface of a SnO2-based electron transport layer. The spin-coating was performed in two stages: the first stage had a rotation speed of 1000 rpm, an acceleration of 500 rpm, and a duration of 8 s; the second stage had a rotation speed of 5000 rpm, an acceleration of 1000 rpm, and a duration of 30 s. Chlorobenzene was added dropwise at the 5th second before the end of the stage, and the mixture was annealed at 150℃ for 30 min. α,ω-dibenzoxazine-poly(ethylene glycol) under imidazole catalysis underwent ring-opening polymerization to obtain a self-healing polymer-bonded perovskite film with an average molecular weight of 10536, welding the interface between the SnO2-based electron transport layer and the perovskite layer. When the perovskite film cooled to 25℃, Spiro-based hole transport layer material was deposited on its surface at a rotation speed of 5000 rpm for 30 s. Finally, 100 μm of material was evaporated under vacuum conditions. A perovskite solar cell was obtained by using a metal electrode with a thickness of nm.

[0040] Example 4

[0041] A 1 mg / mL aqueous solution of cyclohexyl-p-toluenesulfonic acid was reacted with an aqueous solution of tin oxide (V) at 20°C. SnO2 :V H2OA homogeneous aqueous solution with a mass ratio of 0.01:100 was formed by mixing α,ω-dibenzoxazine heptane (1:3) and spin-coating it onto a dry ITO transparent substrate at 3000 rpm for 30 s. The substrate was then annealed in air at 150°C for 30 min to form a SnO2-based electron transport layer. A self-made α,ω-dibenzoxazine heptane was dispersed in N-methylpyrrolidone at a mass concentration of 10 mg / mL. 19.80 mg CsI, 13.53 mg MACl, 16.20 mg MABr, 224.40 mg FAI, and 742.20 mg PbI2 were dissolved in 1 mL of a 4:1 mixture of DMF and DMSO to prepare a ternary cationic perovskite solution. The mass ratio of α,ω-dibenzoxazine heptane to the perovskite solution was 0.01:1. The mixture was stirred at 800 rpm for 2 seconds. A uniform modified perovskite solution was formed. In an N2 glove box, the uniform modified perovskite solution was spin-coated onto the surface of a SnO2-based electron transport layer. The spin-coating was performed in two stages: the first stage had a rotation speed of 500 rpm, an acceleration of 100 rpm, and a duration of 6 s; the second stage had a rotation speed of 5000 rpm, an acceleration of 1000 rpm, and a duration of 30 s. Chlorobenzene was added dropwise at the 10th second before the end of the spin-coating. The mixture was annealed at 150℃ for 10 min. α,ω-dibenzoxazine-heptane underwent ring-opening polymerization catalyzed by cyclohexyl-p-toluenesulfonic acid to obtain a self-healing polymer-bonded perovskite film with an average molecular weight of 10178, forming a welded interface between the SnO2-based electron transport layer and the perovskite layer. When the perovskite film cooled to 25℃, Spiro-based hole transport layer material was deposited on its surface at a rotation speed of 5000 rpm for 30 s. Finally, 100 μm of material was evaporated under vacuum conditions. A perovskite solar cell was obtained by using a metal electrode with a thickness of nm.

[0042] Example 5

[0043] A 3 mg / mL aqueous solution of p-toluenesulfonic acid was reacted with an aqueous solution of tin oxide (V) at 20°C. SnO2 :V H2OA homogeneous aqueous solution with a mass ratio of 0.5:100 was formed by mixing α,ω-dibromobenzoxazine-poly(dimethylsiloxane) at a ratio of 1:3 and spin-coating it onto a dry ITO transparent substrate at 3000 rpm for 30 s. The substrate was then annealed in air at 150°C for 30 min to form a SnO2-based electron transport layer. A self-made α,ω-dibromobenzoxazine-poly(dimethylsiloxane) was dispersed in ultra-dry chloroform at a mass concentration of 15 mg / mL. 19.80 mg CsI, 13.53 mg MACl, 16.20 mg MABr, 224.40 mg FAI, and 742.20 mg PbI2 were dissolved in 1 mL of a 4:1 mixture of DMF and DMSO to prepare a ternary cationic perovskite solution. The mass ratio of α,ω-dibromobenzoxazine-poly(dimethylsiloxane) to the perovskite solution was 0.5:1. The mixture was stirred at 900 rpm for 4 minutes. A uniform modified perovskite solution was formed. In an N2 glove box, the uniform modified perovskite solution was spin-coated onto the surface of a SnO2-based electron transport layer. The spin-coating was performed in two stages: the first stage had a rotation speed of 500 rpm, an acceleration of 100 rpm, and a duration of 6 s; the second stage had a rotation speed of 5000 rpm, an acceleration of 1000 rpm, and a duration of 30 s. Chlorobenzene was added dropwise at the 8th s before the end of the stage, and the mixture was annealed at 150℃ for 10 min. α,ω-dibromobenzoxazine-poly(dimethylsiloxane) underwent ring-opening polymerization catalyzed by p-toluenesulfonic acid to obtain a self-healing polymer-bonded perovskite film with an average molecular weight of 43658, welding the interface between the SnO2-based electron transport layer and the perovskite layer. When the perovskite film cooled to 25℃, Spiro-based hole transport layer material was deposited on its surface at a rotation speed of 5000 rpm for 30 s. Finally, 100 μm of material was evaporated under vacuum conditions. A perovskite solar cell was obtained by using a metal electrode with a thickness of nm.

[0044] Example 6

[0045] A 2 mg / mL aqueous solution of p-toluenesulfonic acid was reacted with an aqueous solution of tin oxide (V) at 15°C. SnO2 :V H2OA homogeneous aqueous solution with a mass ratio of 0.30:100 was formed by mixing a 1:3 ratio of CsI, MACl, MABr, FAI, and PbI2 in air at 150°C for 30 min to form a SnO2-based electron transport layer. A ternary cationic perovskite solution was prepared by dissolving 19.80 mg CsI, 13.53 mg MACl, 16.20 mg MABr, 224.40 mg FAI, and 742.20 mg PbI2 in 1 mL of a 4:1 mixture of DMF and DMSO. The perovskite solution was then spin-coated onto the SnO2-based electron transport layer in an N2 glove box in two stages: the first stage at 1000 rpm with an acceleration of 200 rpm for 10 s, and the second stage at 5000 rpm with an acceleration of 1000 rpm for 25 s. The spin-coating was completed in the fifth-to-last stage. Chlorobenzene containing a self-made α,ω-dibromobenzoxazine heptane at a concentration of 1 mg / mL was added dropwise at 150 °C for 20 min. The mixture was then annealed at 150 °C for 20 min. The α,ω-dibromobenzoxazine heptane underwent ring-opening polymerization catalyzed by p-toluenesulfonic acid to obtain a self-healing polymer welding perovskite film with an average molecular weight of 42722, which welded the interface between the SnO2-based electron transport layer and the perovskite layer. When the perovskite film was cooled to 25 °C, Spiro-based hole transport layer material was deposited on its surface at a rotation speed of 5000 rpm for 30 s. Finally, a 100 nm thick metal electrode was deposited under vacuum to obtain a perovskite solar cell.

[0046] Example 7

[0047] A 2 mg / mL imidazole aqueous solution was reacted with a tin oxide aqueous solution at 15°C (V SnO2 :V H2OA homogeneous aqueous solution with a mass ratio of 0.01:100 was formed by mixing a 1:3 ratio of sodium chloride and sodium sulfate. This solution was then spin-coated onto a dry ITO transparent substrate at 3000 rpm for 30 s, followed by annealing in air at 150°C for 30 min to form a SnO2-based electron transport layer. A ternary cationic perovskite solution was prepared by dissolving 19.80 mg CsI, 13.53 mg MACl, 16.20 mg MABr, 224.40 mg FAI, and 742.20 mg PbI2 in 1 mL of a 4:1 mixture of DMF and DMSO. This perovskite solution was then spin-coated onto the SnO2-based electron transport layer in an N2 glove box in two stages: the first stage at 1000 rpm with an acceleration of 200 rpm for 10 s, and the second stage at 5000 rpm with an acceleration of 1000 rpm for 30 s. The spin-coating was completed in the 10th stage from the end of the spin-coating process. Chlorobenzene containing a self-made α,ω-dichlorobenzoxazine poly(ethylene glycol) at a mass concentration of 0.01 mg / mL was added dropwise at 150 °C for 30 min. The mixture was then annealed at 150 °C for 30 min. α,ω-dichlorobenzoxazine poly(ethylene glycol) underwent ring-opening polymerization catalyzed by imidazole to obtain a self-healing polymer-bonded perovskite film with an average molecular weight of 34264, forming a SnO2-based electron transport layer and perovskite layer interface. When the perovskite film was cooled to 25 °C, Spiro-based hole transport layer material was deposited on its surface at a spin-coating speed of 5000 rpm for 30 s. Finally, a 100 nm thick metal electrode was deposited under vacuum to obtain a perovskite solar cell.

Claims

1. A method for interfacial welding of perovskite solar cells using a self-healing polymer, characterized in that: Includes the following steps: (1) The catalyst aqueous solution was mixed with the tin oxide aqueous solution at 15~30℃ and spin-coated onto the surface of a dry ITO transparent substrate at 3000 rpm for 30 s. The substrate was then annealed in air at 150℃ for 30 min to form a SnO2-based electron transport layer. The V of the tin oxide aqueous solution was... SnO2 :V H2O The ratio is 1:3, and the mass ratio of catalyst to tin oxide is 0.01~0.5:100; (2) The benzoxazine derivative is dispersed in an organic solvent, and the mass ratio of the benzoxazine derivative to the ternary cationic perovskite solution is 0.01~0.5:

1. The mixture is stirred at 600~900 rpm for 1~4 h to form a uniform modified perovskite solution. (3) In an N2 glove box, spin-coat the solution described in step (2) onto the surface of the SnO2-based electron transport layer described in step (1). Spin-coating is done in two stages. In the first stage, the rotation speed is 500~1000 rpm, the duration is 6~10s, and the acceleration is 100~500 rpm. In the second stage, the rotation speed is 5000 rpm, the duration is 25~30s, and the acceleration is 1000 rpm. In the last 5~10s, the antisolvent is added dropwise. Then, the mixture is annealed at 150℃ for 10~30 min to obtain a perovskite film with a self-healing polymer welded interface between the SnO2-based electron transport layer and the perovskite layer. (4) When the perovskite film described in step (3) is cooled to 25°C, a spiro-based hole transport layer material is deposited on its surface. The spin coating speed is 4000~5000 rpm and the duration is 30 s. (5) Finally, a 100 nm metal electrode was deposited under vacuum conditions to obtain a perovskite solar cell. The catalyst mentioned in step (1) is one of p-toluenesulfonic acid, imidazole or cyclohexyl p-toluenesulfonic acid, and the mass concentration of the aqueous solution of the catalyst is 1~5 mg / mL; The benzoxazine derivative described in step (2) has the following general structural formula: Where R1 = CH2, or R2 = H, Cl, or Br; n = 1~10; The organic solvent mentioned in step (2) is one or two of ultra-dry chloroform, N,N-dimethylformamide (DMF), N-methylpyrrolidone or dimethyl sulfoxide (DMSO), and the mass concentration of the benzoxazine derivative in the organic solvent is 5~20 mg / mL; The ternary cationic perovskite molecular formula mentioned in step (2) is Cs 0.05 FA 0.85 MA 0.10 Pb(I 0.97 Br 0.03 3; The ternary cation perovskite solution is obtained by dissolving CsI, MACl, MABr, FAI, and PbI2 in a mixed solvent of DMF and DMSO, with a volume ratio of DMF to DMSO of 4:1; the mass concentrations of CsI, MACl, MABr, FAI, and PbI2 are 19.80 mg / mL, 13.53 mg / mL, 16.20 mg / mL, 224.40 mg / mL, and 742.20 mg / mL, respectively. The antisolvent mentioned in step (3) is chlorobenzene, or chlorobenzene containing benzoxazine derivatives, with a mass concentration of 0.01~1 mg / mL.

2. The self-healing polymer formed by the method for interfacial welding of perovskite solar cells using a self-healing polymer as described in claim 1, characterized in that... The general structural formula is as follows: In the formula, m = 42~100; the average molecular weight of the self-healing polymer is 10178~43658.

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