A perovskite solar cell with a hole transport layer doped with tin oxysulfide and a preparation method thereof

Abstract

The invention discloses a perovskite solar cell with a hole transport layer doped with tin oxysulfide and a preparation method thereof, comprising the following steps: washing and drying a glass / ITO substrate; spin-coating a diluted SnO2 colloid aqueous solution on the ITO glass; spin-coating a diluted Al2O3 isopropanol solution on the SnO2 film; spin-coating a 3D perovskite precursor solution on the Al2O3 film; spin-coating a BAI isopropanol solution on the 3D perovskite film; and spin-coating a hole transport layer Spiro‑OMeTAD:SnS 1‑x O 2x The dispersion is spin-coated onto a 2D perovskite film; a gold electrode is deposited onto the hole transport layer using vacuum evaporation. This method avoids the high-temperature treatment required in conventional solar cell fabrication, thereby reducing production costs. It also significantly improves the photoelectric conversion efficiency and stability of solar cells, making it suitable for large-scale industrial production, such as roll-to-roll and blade coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of material chemistry and biology, and in particular relates to a perovskite solar cell with a hole transport layer doped with tin oxysulfide and a preparation method thereof. Background Art

[0002] Currently, the main energy source for consumption is still natural gas, coal, oil and other non-renewable fossil fuels. However, the reserves of these energy sources are insufficient to meet the needs of social development. Therefore, social development that relies on fossil fuels is unstable. In order to meet the needs of social development and mitigate the greenhouse effect caused by fossil fuels, people urgently need to develop new green energy sources. Among the many renewable energy sources, solar energy has attracted researchers due to its huge energy, wide radiation range, and clean and pollution-free characteristics. Among them, perovskite materials have attracted researchers due to their excellent photoelectric properties, low-cost process preparation, and abundant raw material reserves. After decades of development, the efficiency of single-junction perovskite solar cells has increased from the initial 3.8% to 25.7%, taking another step towards its theoretical limit and commercialization.

[0003] In the traditional nip structure, the hole transport layer (HTL) is crucial. It not only extracts and transports holes and blocks electrons, but also bears the heavy responsibility of blocking water and oxygen penetration. The preferred hole transport materials for high-efficiency perovskite solar cells are often Spiro-OMeTAD and its additives Li-TFSI and TBP. The organic small molecule material Spiro-OMeTAD has poor hole mobility and conductivity, so it must rely on Li-TFSI and TBP. However, the hygroscopicity of Li-TFSI and the dedoping property of TBP affect the long-term stability of the battery, restricting the commercial development of perovskite batteries. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a hole transport layer doped with tin oxysulfide (Spiro-OMeTAD: SnS 1-x O 2x As a hole transport layer) perovskite solar cell and its preparation method. Without sacrificing the existing performance, using SnS 1-x O 2x The material further optimizes the battery based on the existing mature formula of Spiro-OMeTAD, effectively improving the dispersion state of the original additives in the hole transport layer, reducing the accumulation of Li-TFSI in the film, making the oxidation of Spiro-OMeTAD more complete and uniform, and lowering its Fermi level and valence band position. The method of the present invention has good repeatability, stability and photoelectric conversion efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] (1) Under ultrasonic conditions, the etched glass / ITO substrate (sheet resistance 15 Ω (sq)) was cleaned with detergent, deionized water, acetone, and isopropyl alcohol in sequence. -1 ) for 30 minutes, and then blow dry the glass / ITO substrate with nitrogen;

[0007] (2) diluting a SnO2 colloidal aqueous solution with deionized water in air; then spin-coating the diluted SnO2 colloidal aqueous solution on an ITO glass, annealing the solution after spin-coating, and then UV-treating the solution to obtain an ITO / SnO2 substrate;

[0008] (3) Spin coating an isopropyl alcohol solution of Al2O3 on the obtained ITO / SnO2 substrate, and annealing to obtain an ITO / SnO2 / Al2O3 substrate;

[0009] (4) In a nitrogen-filled glove box, the precursor solution of three-dimensional perovskite [Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 )3:CNT:TiO2 (abbreviated as CsFAMA:CNT:TiO2)], and after annealing, an ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 substrate was obtained;

[0010] (5) Spin coating an isopropanol solution of BAI on the obtained ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 substrate, and annealing to obtain an ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 substrate;

[0011] (6) Spin-coat the hole transport layer Spiro-OMeTAD:SnS on the obtained (BA)2PbI4 1-x O 2x dispersion to obtain ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS 1-x O 2x substrate;

[0012] (7) In ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS 1-x O 2xOn the substrate, gold electrodes were deposited by vacuum evaporation to obtain a structure of ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS 1-x O 2x / Au perovskite solar cells.

[0013] In step (2), the dilution process of the SnO2 colloidal aqueous solution is as follows: a commercially available SnO2 colloidal aqueous solution (solid content is 20 wt%) is diluted with deionized water, and the diluted SnO2 colloidal aqueous solution has a solid content of 10~15wt%, and is used after stirring for at least 60 minutes; the annealing conditions are first annealing at 120°C for 5 minutes, then annealing at 150°C for 10 minutes, and the UV treatment time is 30 minutes.

[0014] In step (3), the process of preparing the isopropanol solution of Al2O3 is as follows: the original Al2O3 isopropanol dispersion is diluted with isopropanol at a volume ratio of 6:1, and the diluted Al2O3 solution is shaken evenly before use; the annealing condition is 150°C for 10 to 20 minutes.

[0015] In step (4), the 3D perovskite precursor solution is specifically Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 )3: CNT:TiO2 (abbreviated as CsFAMA:CNT:TiO2) perovskite precursor solution, the preparation process is as follows: a certain amount of CNT:TiO2 powder is dissolved in DMF / DMSO (v:v=8.5 / 1.5) mixed solvent to obtain a concentration of 0.025 mg mL -1 Then, PbI2, PbBr2, FAI, MAI, and CsI were dissolved in the sonicated mixed polar solution at a molar ratio of 0.05:0.81:0.14:0.78:0.22 to obtain a concentration of 1.4 mol L -1 Cs 0.05 (MA 0.15 FA 0.85 ) 0.95 Pb(I 0.85 Br 0.15 )3: CNT:TiO2 solution was stirred for at least 12 hours before use. Perovskite films were prepared using a two-step procedure (1000 rpm for 5 seconds and 4000 rpm for 13 seconds). The antisolvent, diethyl ether, was rapidly added dropwise to the rotating substrate 8 seconds after the start of the second step. Annealing conditions were 90°C for 5 minutes, followed by 120°C for 10 minutes.

[0016] In step (5), the preparation process of BAI isopropanol solution is as follows: BAI powder is dissolved in isopropanol to obtain 5 mg mL -1 The BAI isopropanol solution was stirred for at least 12 hours before use; the annealing condition was 100°C for 10 minutes.

[0017] In step (6), Spiro-OMeTAD:SnS 1-x O 2x The preparation process of the dispersion is as follows: a certain amount of SnS 1-x O 2x Dissolved in chlorobenzene solution, and obtained uniformly dispersed SnS after ultrasonication. 1-x O 2x chlorobenzene dispersion, add 1 mL of SnS 1-x O 2x 72.5 mg of Spiro-OMeTAD powder, 28.5 μL of TBP and 18 μL of Li-TFSI in acetonitrile were added to the chlorobenzene dispersion and stirred for 5-10 hours before use without annealing.

[0018] Among them, SnS 1-x O 2x The preparation process is as follows: sinter tin sulfide in a muffle furnace at 100℃~250℃ for 20~30 minutes to properly oxidize it to obtain SnS with different x values. 1-x O 2x , 0 <x<0.5。

[0019] Spiro-OMeTAD:SnS prepared by the above preparation method 1-x O 2x As a hole transport layer of perovskite solar cells, specifically, the thickness of SnO2 film is 40 nm, the thickness of Al2O3 film is 100 nm, the thickness of 3D perovskite film is 500 nm, the thickness of 2D perovskite film is 70 nm, Spiro-OMeTAD:SnS 1-x O 2x The thickness of the film is 100 nm, and the thickness of the gold electrode is 100 nm.

[0020] Compared with the methods in existing literature, the method of the present invention can improve the performance of solar cells as much as possible under the same conditions, avoid the high-temperature treatment in the previous solar cell preparation process, thereby reducing production costs, and is conducive to the commercial large-scale preparation and production of perovskite cells. It is also suitable for large-scale roll-to-roll industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a schematic diagram of the battery structure of the present invention;

[0022] Figure 2 SnS 1-x O 2x (a) Full XPS spectrum and (b) high-resolution Sn 3d spectrum;

[0023] Figure 3 ITO / SnO2 / Al2O3 / CSFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD / Au and ITO / SnO2 / Al2O3 / CSFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS prepared in Example 1 1-x O 2x Current-voltage curve of the solar cell with Au / Au;

[0024] Figure 4 ITO / SnO2 / Al2O3 / CSFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD / Au and ITO / SnO2 / Al2O3 / CSFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS prepared in Example 1 1-x O 2x IPCE curve of solar cell with Au / Au;

[0025] Figure 5 SnS prepared in Example 1 1-x O 2x XRD pattern of

[0026] Figure 6 (a) V of the battery oc and (b) J sc as a function of light intensity (Ln(I)), and a linear fit to the data (solid line);

[0027] Figure 7 ITO / SnO2 / Al2O3 / CSFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD / Au and ITO / SnO2 / Al2O3 / CSFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS prepared in Example 1 1-x O 2x Stability test curve of solar cells with Au / Au.

[0028] In the attached figure, the SnS in the improved battery or device 1-x O 2xThe optimal concentration was 0.3 mg mL -1 . DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. However, the present invention can be implemented in many different forms, and the present invention should not be interpreted as being limited to the specific embodiments set forth herein.

[0030] For details on the preparation of CNT:TiO2, please refer to the literature Multifunctional CNT:TiO2 additives inspiro-OMeTAD layer for highly efficient and stable perovskite solar cells. EcoMat 2021, 1-13.

[0031] Example 1

[0032] A Spiro-OMeTAD:SnS 1-x O 2x The preparation method of the perovskite solar cell as the hole transport layer is as follows:

[0033] (1) Etching process of glass / ITO substrate: Cut the purchased large-area unetched glass / ITO substrate into small-area strips of 2 cm × 10 cm. Use a high-temperature tape with a width of 8 mm to stick it in the middle position along the 10 cm direction to ensure that the tape-free position on both sides is 6 mm. Mix commercially available concentrated hydrochloric acid and water in a volume ratio of 6:4 to form an acid solution. Place the glass / ITO with the tape into the acid solution, and then immediately add a certain amount of zinc powder. Shake the solution evenly and slowly to make the etching process uniform. After a period of time, take out the glass / ITO, remove the tape, and further cut it into 2 cm × 2 cm square glass / ITO to obtain the glass / ITO of the appropriate size used in the experiment.

[0034] (2) Under ultrasonic wave, the etched glass / ITO substrate (resistance 15 Ω (sq)) was cleaned with detergent, deionized water, acetone and isopropyl alcohol in sequence. -1 ) for 30 minutes. The glass / ITO substrate was then dried with nitrogen and treated with UV-ozone at 45°C for 30 minutes before coating the electron transport layer.

[0035] (3) The dilution process of the SnO2 colloidal aqueous solution is as follows: a commercially available SnO2 colloidal aqueous solution (solid content of 20 wt%) was diluted with deionized water at a volume ratio of 1:2. The solid content of the diluted SnO2 colloidal aqueous solution was 13.3 wt%, and the solution was stirred for 60 minutes before use. 100 μL of the obtained diluted SnO2 colloidal aqueous solution was spin-coated on a pre-cleaned ITO glass (5500 rpm, 10 s), and then annealed at 120°C for 5 minutes, annealed at 150°C for 10 minutes, and then treated with UV ozone at 45°C for 60 minutes.

[0036] (4) The original Al2O3 isopropanol dispersion (20 wt.%) was diluted with isopropanol at a volume ratio of 6:1 to obtain an Al2O3 precursor solution (2.86 wt.%). 100 μL of the diluted Al2O3 precursor solution was then spin-coated onto the ITO / SnO2 substrate at 3500 rpm for 20 seconds and heated at 150 °C for 10–20 minutes. Afterwards, the ITO / SnO2 / Al2O3 substrate was immediately transferred to a glove box.

[0037] (5) 3D perovskite precursor solution Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 )3: The preparation process of CNT:TiO2 (CsFAMA:CNT:TiO2) is as follows: a certain amount of CNT:TiO2 powder was dissolved in a DMF / DMSO (v:v=8.5 / 1.5) mixed solution to obtain a concentration of 0.025 mg mL -1 18.2 mg of CsI, 194.5 mg of FAI, 31.7 mg of MAI, 500.2 mg of PbI2, and 115.6 mg of PbBr2 were dissolved in 1 mL of the mixed polar solution obtained above to obtain a concentration of 0.025 mg / mL. -1 The molar concentration of CNT:TiO2 solution was 1.4 mol L -1 Cs 0.05 (MA 0.15 FA 0.85 ) 0.95 Pb(I 0.85 Br 0.15)3:CNT:TiO2 solution was stirred for 12 hours before use. 30 μL of the perovskite precursor solution was dropped onto an ITO / SnO2 / Al2O3 substrate. The perovskite film was prepared using a two-step procedure (1000 rpm for 5 s and 4000 rpm for 13 s). Eight seconds after the start of the second step, 800 μL of the antisolvent diethyl ether was rapidly added to the rotating substrate. After the rotation ended, the sample was immediately transferred to a hot plate and annealed at 90°C for 5 minutes and then at 120°C for 10 minutes to obtain an ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 substrate.

[0038] (6) Preparation of BAI isopropanol solution: 5 mg of BAI powder was dissolved in 1 mL of isopropanol solution and stirred for 12 hours before use. After the film cooled, a 5 mg / mL solution was coated on the perovskite film at a speed of 6000 rpm. −l 50 μL of BAI isopropanol solution was added, and the film was annealed at 100 °C for 10 min to remove excess solvent, obtaining a 70 nm thick 2D perovskite layer.

[0039] (7) SnS 1-x O 2x Preparation process: Using 99% pure stannous sulfide purchased from Aladdin, the oxygen content is regulated by controlling the temperature and time. For example, stannous sulfide is sintered in a muffle furnace at 100°C, 150°C, 200°C, and 250°C for 20 minutes to properly oxidize, resulting in SnS with different x values. 1-x O x , the value range of x is 0 <x<0.5。

[0040] In this application, stannous sulfide was sintered in a muffle furnace at 100°C for 20 minutes to be properly oxidized to obtain SnS with x=0.35. 1-x O 2x , namely SnS 0.65 O 0.7 .

[0041] Table 1. Sn 3d 5 / 2 Data obtained after peak separation

[0042]

[0043] Measured SnS 1-x O 2x Full XPS spectrum ( Figure 2 Figure a) is used to analyze the elemental complex, which shows obvious characteristic peaks of Sn, S and O. High-resolution Sn 3d spectrum is shown in Figure 3 Figure 2As shown in b, it is used to determine the oxidation state of the Sn element, which can be divided into two components at 485.50 eV and 487.17 eV, corresponding to Sn 2+ (blue part) and Sn 4+ (Green part). Table 1 is Sn 3d 5 / 2 From the data obtained after peak separation processing, it can be seen that the content of tetravalent Sn is 35.0% and the content of divalent Sn is 65.0%, that is, x is equal to 0.35 and 1-x is equal to 0.65.

[0044] A certain amount of SnS 1-x O 2x (x=0.35) was dissolved in chlorobenzene and uniformly dispersed SnS was obtained after ultrasonication. 1-x O 2x Chlorobenzene dispersion, SnS 0.65 O 0.7 The concentrations were 0 mg mL -1 , 0.2 mg mL -1 , 0.3 mg mL -1 , 0.6 mg mL -1 , with the optimal concentration being 0.3 mg mL -1 . Add 1 mL of chlorobenzene or 1 mL of 0.3 mg mL -1 SnS 1-x O 2x 72.5 mg of Spiro-OMeTAD powder, 28.5 μL of TBP, and 18 μL of commercially available Li-TFSI in acetonitrile (the concentration of Li-TFSI was 520 mg mL) were added to the chlorobenzene dispersion. -1 After the film cooled, 25 μL of Spiro-OMeTAD or Spiro-OMeTAD:SnS 1-x O 2x The solution was coated on the (BA)2PbI4 thin film at a rotation speed of 4500 rpm and dried naturally (without annealing step).

[0045] (8) A gold electrode with a thickness of 100 nm was obtained by thermal evaporation in a vacuum chamber. The effective area of ​​the battery was controlled to be 0.04 cm 2 , the structure of the battery is as follows Figure 1 shown.

[0046] Figure 3The unmodified cells with the structures of ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD / Au and ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS 1-x O 2x The current density-voltage curve of the improved battery with Au is shown in Table 2. The photovoltaic parameters of the two devices are shown in Table 2. From the forward scan data in the table, it can be clearly seen that the voltage of the improved battery is increased from 1.20 V to 1.23 V, and the current density is increased from 24.85 mA cm -2 increased to 25.50 mA cm -2 The fill factor increased from 0.75 to 0.78, and the photoelectric conversion efficiency increased from 22.7% to 24.5%. At the same time, the hysteresis factor (HI) of the improved cell was significantly reduced. The inset shows the photoelectric conversion efficiency statistics of 30 devices under the same experimental and test conditions, respectively. It can be clearly seen that the improved cell has better efficiency and reproducibility.

[0047] Table 2. Parameter statistics of PSC devices before and after improvement.

[0048]

[0049] Figure 4 The unmodified cells of ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD / Au and the cells of ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS 1-x O 2x Monochromatic incident photon-to-electron conversion efficiency (IPCE) spectra of the improved cells with and without SnS 1-x O 2x The integrated currents of the PSCs were 24.06 mA cm -2 and 24.29 mA cm -2 , which is consistent with the J obtained from the JV curve sc Very well matched.

[0050] Figure 5 Shows SnS 1-x O 2x From the XRD pattern, the characteristic peaks of SnS and SnO2 can be clearly found, proving the existence of these two materials.

[0051] Figure 6a in the figure shows the open circuit voltage V oc The relationship between the illumination intensity I and the illumination intensity I. It can be seen that the slope of the linear fitting of the unmodified battery of ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD / Au is 1.60k B T / e, and based on ITO / SnO2 / Al2O3 / CsFAMA:CNT:TiO2 / (BA)2PbI4 / Spiro-OMeTAD:SnS 1-x O 2x The slope of the linear fitting of the improved battery with Au / Au is 1.41 k B T / e, where k B is the Boltzmann constant, T is the temperature, e is the charge, and the slope k B The magnitude of the T / e deviation from 1 reflects the defect-assisted nature of the device, and the above results further confirm that non-radiative recombination in the perovskite layer is largely suppressed. sc The logarithm of is proportional to the logarithm of the light intensity I, which can be expressed by In(J sc )αλIn(I) indicates that Figure 6 b in the figure shows that it contains SnS 1-x O 2x The slope of the fitting line of the perovskite solar cell is λ (0.97) higher than that of the perovskite solar cell without SnS. 1-x O 2x The fitting slope λ (0.96) of the perovskite solar cell is closer to 1, which indicates that the SnS 1-x O 2x The defect-assisted recombination in the PSCs is less.

[0052] Figure 7 The results show that the morphology of the spherical nanostructured ... 1-x O 2x Stability test of PSCs at room temperature with a humidity of 30%±10%, continuous illumination with standard sunlight and a temperature of 85°C. 1-x O 2x The PSC based on Spiro-OMeTAD still maintained 94.4% of its initial efficiency after 1680 hours, while the PSC based on Spiro-OMeTAD only maintained 61.0% of its initial efficiency after 1680 hours. 1-x O 2xThe PSC based on Spiro-OMeTAD maintained 82.2% of its initial efficiency, while the PSC based on Spiro-OMeTAD only maintained 56.5% of its initial efficiency. 1-x O 2x The PSC based on MgO maintained 89.8% of its initial efficiency, while the PSC based on Spiro-OMeTAD only maintained 71.9% of its initial efficiency. Therefore, the three tests above show that the optimized battery exhibits excellent stability under various conditions.

[0053] The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Without departing from the principle of the present invention, any improvement and modification should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a perovskite solar cell with a hole transport layer doped with tin oxysulfide, characterized in that: The following steps are involved: (1) Clean and dry the etched glass / ITO substrate and treat it with UV ozone before use; (2) diluting the SnO2 colloidal aqueous solution with deionized water; then spin-coating the diluted SnO2 colloidal aqueous solution on the ITO glass, annealing after spin coating, and then performing UV treatment to obtain an ITO / SnO2 substrate; (3) Spin coating an isopropyl alcohol solution of Al2O3 on the obtained ITO / SnO2 substrate, and annealing to obtain an ITO / SnO2 / Al2O3 substrate; (4) In a nitrogen-filled glove box, a three-dimensional (3D) perovskite precursor solution was spin-coated on the obtained ITO / SnO2 / Al2O3 substrate, and after annealing, an ITO / SnO2 / Al2O3 / 3D perovskite substrate was obtained; the 3D perovskite precursor solution was specifically Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 )3: CNT:TiO2 (CsFAMA:CNT:TiO2) perovskite precursor solution, the preparation process is as follows: a certain amount of CNT:TiO2 powder is dissolved in a DMF / DMSO mixed solvent with a volume ratio of 8.5:1.5 to obtain a concentration of 0.025 mg mL -1 CsI, FAI, MAI, PbI2, and PbBr2 were dissolved in 1 mL of a mixed polar solution at a molar ratio of 0.05:0.81:0.14:0.78:0.

22. The concentration obtained above was 0.025 mg mL -1 The molar concentration of CNT:TiO2 solution was 1.4 mol L -1 Cs 0.05 (MA 0.15 FA 0.85 ) 0.95 Pb(I 0.85 Br 0.15 )3: CNT:TiO2 solution, and use after stirring for at least 12 hours; (5) Spin coating an isopropanol solution of BAI on the obtained ITO / SnO2 / Al2O3 / 3D perovskite substrate, and obtaining a two-dimensional (2D) perovskite film after annealing to obtain an ITO / SnO2 / Al2O3 / 3D perovskite / 2D perovskite substrate; (6) Spin coating the hole transport layer Spiro-OMeTAD:SnS on the 2D perovskite film 1-x O 2x Dispersion liquid, ITO / SnO2 / Al2O3 / 3D perovskite / 2D perovskite / Spiro-OMeTAD:SnS 1-x O 2x substrate; (7) Using vacuum evaporation method to obtain ITO / SnO2 / Al2O3 / 3D perovskite / 2D perovskite / Spiro-OMeTAD:SnS 1-x O 2x Gold electrodes were evaporated on the substrate to obtain a structure of ITO / SnO2 / Al2O3 / 3D perovskite / 2D perovskite / Spiro-OMeTAD:SnS 1-x O 2x / Au perovskite solar cells.

2. The preparation method according to claim 1, characterized in that In step (2), the solid content of the diluted SnO2 colloidal aqueous solution is 10-15 wt%, and it is stirred for at least 60 minutes after dilution before use; the annealing conditions are first annealing at 120°C for 5 minutes and then annealing at 150°C for 10 minutes.

3. The preparation method according to claim 1, characterized in that In step (3), the process of preparing the isopropanol solution of Al2O3 is as follows: the original Al2O3 isopropanol dispersion is diluted with isopropanol at a volume ratio of 6:1, and the diluted Al2O3 solution is shaken evenly before use; the annealing condition is annealing at 150°C for 10 to 20 minutes.

4. The preparation method according to claim 1, characterized in that In step (4), the annealing conditions are first annealing at 90°C for 5 minutes and then annealing at 120°C for 10 minutes.

5. The preparation method according to claim 1, characterized in that In step (5), the isopropanol solution of BAI was prepared as follows: BAI powder was dissolved in isopropanol to obtain 5 mg mL -1 The BAI isopropanol solution was stirred for at least 12 hours before use; the annealing condition was 100°C for 10 minutes.

6. The preparation method according to claim 1, characterized in that In step (6), Spiro-OMeTAD:SnS 1-x O 2x The preparation process of the dispersion is as follows: a certain amount of SnS 1-x O 2x Dissolved in chlorobenzene, SnS in the solution 1-x O 2x The concentration is 0.2 mg / mL -1 ~0.6 mg mL -1 After ultrasonication, uniformly dispersed SnS 1-x O 2x chlorobenzene dispersion, add 1 mL of SnS 1-x O 2x To the chlorobenzene dispersion, 72.5 mg of Spiro-OMeTAD powder, 28.5 μL of TBP, and 18 μL of Li-TFSI in acetonitrile were added and stirred for 5 to 10 hours before use.

7. The preparation method according to claim 1 or 6, characterized in that SnS 1-x O 2x The preparation process is as follows: sinter tin sulfide in a muffle furnace at 100℃~250℃ for 20~30 minutes to properly oxidize it to obtain SnS with different x values. 1-x O 2x , 0 <x<0.5。 8. A perovskite solar cell with a hole transport layer doped with tin oxysulfide, prepared by the preparation method according to any one of claims 1 to 7.

9. The perovskite solar cell according to claim 8, characterized in that The thickness of SnO2 film is 40 nm, the thickness of Al2O3 film is 100 nm, the thickness of 3D perovskite film is 500 nm, the thickness of 2D perovskite film is 70 nm, Spiro-OMeTAD:SnS 1-x O 2x The thickness of the film is 100 nm, and the thickness of the gold electrode is 100 nm.

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