Blade coating preparation method of perovskite solar cell using potassium hexafluorophosphate

Abstract

The invention relates to the technical field of photovoltaic power generation, in particular to a blade coating preparation method of a perovskite solar cell using potassium hexafluorophosphate, and the method can effectively passivate defects of a perovskite film and inhibit ion migration through the introduced potassium hexafluorophosphate, thereby fundamentally reducing the hysteresis effect of a device, the potassium ions can be embedded into octahedral gaps of perovskite crystal lattices, the hexafluorophosphate ions can fill up iodine vacancy defects, the potassium ions and the hexafluorophosphate ions jointly inhibit migration of iodine ions in the perovskite crystal lattices, the photoelectric conversion efficiency of a finally prepared device is improved to 22.50% from 21.07%, the hysteresis factor is reduced to 4.1% from 11.8%, the film crystallization quality and the device stability are remarkably improved, and the performance of the device is improved. And an effective scheme is provided for large-area and industrial production of high-performance perovskite solar cells.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic power generation, and particularly relates to a doctor blade coating preparation method of a perovskite solar cell using potassium hexafluorophosphate. BACKGROUND

[0002] In recent years, perovskite solar cells have attracted extensive attention of scientists due to high power conversion efficiency, flexible device preparation, low cost and other advantages. Generally, a doctor blade coating method can be used to prepare large-area perovskite solar cells, which has great industrialization potential. However, the crystalline quality of a large-area perovskite thin film prepared under environmental conditions is usually poor due to the influence of water and oxygen, which leads to problems such as low efficiency, large hysteresis and poor stability of the prepared device.

[0003] For example, a perovskite film, a preparation method thereof and a perovskite solar cell are disclosed in Chinese Patent No. CN119451521A. The preparation method of the perovskite film comprises: preparing a divalent inorganic salt aqueous solution, the divalent inorganic salt in the divalent inorganic salt aqueous solution is an inorganic salt corresponding to a divalent cation of a perovskite, and the divalent inorganic salt aqueous solution contains a cationic surfactant; and performing film forming treatment on the divalent inorganic salt aqueous solution to obtain a divalent inorganic salt film; and converting the divalent inorganic salt in the divalent inorganic salt film into an organic-inorganic hybrid perovskite to obtain a perovskite film. Based on the action of the cationic surfactant, the surface tension of the divalent inorganic salt aqueous solution is reduced, the film forming process is easy to spread, and the nucleation-growth of the divalent inorganic salt is optimized, thereby reducing the risk of pinhole formation of the divalent inorganic salt film, and finally a smooth and dense perovskite film can be obtained. However, this scheme still has the problems of large hysteresis effect and low photoelectric conversion efficiency of the device when the doctor blade coating method is used to prepare the perovskite solar cell under environmental conditions (air environment) due to the poor crystalline quality of the perovskite thin film and serious ion migration. SUMMARY

[0004] To this end, the present application provides a doctor blade coating preparation method of a perovskite solar cell using potassium hexafluorophosphate, which is used to overcome the problems of large hysteresis effect and low photoelectric conversion efficiency of the device when the doctor blade coating method is used to prepare the perovskite solar cell under environmental conditions (air environment) due to the poor crystalline quality of the perovskite thin film and serious ion migration in the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides a doctor blade coating preparation method of a perovskite solar cell using potassium hexafluorophosphate, which comprises: Step S1, pretreating an indium tin oxide conductive glass to obtain a pretreated indium tin oxide conductive glass; Step S2, under the premise of environmental conditions, doctor blade coating a hole transport layer on the surface of the pretreated indium tin oxide conductive glass to obtain a first indium tin oxide conductive glass; Step S3, under the premise of environmental conditions, a perovskite precursor solution containing potassium hexafluorophosphate is scraped on the surface of the hole transport layer of the first indium tin oxide conductive glass to obtain a substrate, and the substrate is transferred into a vacuum cavity for vacuum treatment, the pressure of the vacuum cavity is 10 Pa, the treatment time of the vacuum treatment is 60 seconds, to obtain a vacuum-treated substrate, and the vacuum-treated substrate is placed on a hot stage at 120 DEG C for annealing for 10 minutes, so that a perovskite film is attached to the surface of the hole transport layer, to obtain a second indium tin oxide conductive glass; Step S4, an electron transport layer is spin-coated on the surface of the perovskite film of the second indium tin oxide conductive glass to obtain a third indium tin oxide conductive glass, and an interface buffer layer is spin-coated on the surface of the electron transport layer of the third indium tin oxide conductive glass to obtain a fourth indium tin oxide conductive glass; Step S5, a metal electrode is deposited on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass to obtain a low-hysteresis perovskite solar cell.

[0006] Further, the pretreatment of the indium tin oxide conductive glass in step S1 comprises: Step S11, the indium tin oxide conductive glass is ultrasonically cleaned with cleaning agent, deionized water, acetone and ethanol to obtain cleaned indium tin oxide conductive glass; Step S12, the cleaned indium tin oxide conductive glass is blown dry with a nitrogen gun to obtain dried indium tin oxide conductive glass; Step S13, the dried indium tin oxide conductive glass is ultraviolet ozone cleaned with an ultraviolet ozone cleaning machine for 20 minutes to obtain pretreated indium tin oxide conductive glass.

[0007] Further, the material of the hole transport layer in step S2 is poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine].

[0008] Further, the scraping of the hole transport layer on the surface of the pretreated indium tin oxide conductive glass in step S2 comprises: Step S21, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] is dissolved in a mixed solvent to obtain a pre-solution, and the pre-solution is heated and stirred at 60 DEG C to obtain a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution, wherein the mixed solvent comprises methanol and chloroform, the ratio of methanol to chloroform is 1:1, and the concentration of the mixed solvent is 1 mg / mL; Step S22, using a doctor blade method to 10 mm / s of the first doctor blade speed poly [bis (4-phenyl) (2, 4, 6-trimethylphenyl) amine] solution is scraped on the surface of the pre-processed indium tin oxide conductive glass, the doctor blade and the pre-processed indium tin oxide conductive glass between the gap is 200 μm, to obtain the doctor blade after the indium tin oxide conductive glass; Step S23, the doctor blade after the indium tin oxide conductive glass is placed on the hot stage at a temperature of 100 ℃ for 10 minutes, to obtain the first indium tin oxide conductive glass.

[0009] Further, the preparation method of the perovskite precursor solution containing potassium hexafluorophosphate in step S3 comprises: Step S31, 21.84 mg of cesium iodide, 645.4 mg of lead iodide, 226.35 mg of formamidinium iodide, 5.8 mg of lead chloride, 1.0 mg-2.0 mg of potassium hexafluorophosphate are dissolved in 1 mL of mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone, to obtain an initial mixed solvent, wherein the volume ratio of N,N-dimethylformamide to N-methyl-2-pyrrolidone is 5:1; Step S31, the initial mixed solvent is stirred to obtain a perovskite precursor solution containing potassium hexafluorophosphate.

[0010] Further, the doctor blade parameters for doctor blading the perovskite precursor solution containing potassium hexafluorophosphate on the surface of the hole transport layer of the first indium tin oxide conductive glass in step S3 comprise: doctor blading the perovskite precursor solution containing potassium hexafluorophosphate on the surface of the hole transport layer of the first indium tin oxide conductive glass at a second doctor blade speed of 9 mm / s, and the gap between the hole transport layer and the doctor blade is 250 μm.

[0011] Further, the step S4 of spin coating an electron transport layer on the surface of the perovskite thin film of the second indium tin oxide conductive glass to obtain a third indium tin oxide conductive glass comprises: Step S411, the electron transport material [6,6]-phenyl-C61-butyric acid methyl ester is dissolved in chlorobenzene and stirred to obtain an electron transport spin coating solution, and the concentration of the electron transport spin coating solution is 22 mg / mL; Step S412, the electron transport spin coating solution is spin coated on the surface of the perovskite thin film by a spin coating method at a spin coating speed of 3000 rpm, and the spin coating time is 30 seconds, to obtain a third indium tin oxide conductive glass.

[0012] Further, the step S4 of spin coating an electron transport layer on the surface of the perovskite thin film of the second indium tin oxide conductive glass to obtain a third indium tin oxide conductive glass comprises: Step S421: Dissolve the interface buffer material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline in isopropanol and stir thoroughly at 60°C to obtain an interface buffer spin-coating solution with a concentration of 0.5 mg / mL. Step S422: The interface buffer spin coating solution is spin-coated onto the surface of the electron transport layer at a spin coating speed of 6000 rpm for 30 seconds to obtain the fourth indium tin oxide conductive glass.

[0013] Further, step S5, which involves depositing a metal electrode on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass to obtain a low-hysteresis perovskite solar cell, includes: Step S51: Select a metal electrode material; Step S52: The metal electrode material is deposited on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass using a vacuum deposition machine, thereby forming a metal electrode on the surface of the interface buffer layer to obtain a low-hysteresis perovskite solar cell. The electrode area of ​​the metal electrode is 0.09 cm². 2 .

[0014] Furthermore, the parameters of the vacuum coating machine include: a vacuum degree of 6 × 10⁻⁶. -4 Pa, evaporation rate is 0.1 nm / s.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the method provides a clean, flat, and surface-energy-optimized pretreated indium tin oxide conductive glass for the subsequent coating of the hole transport layer through step S1; the method also successfully prepares the hole transport layer in an air environment without the need for inert gas protection through step S2 by the coating method, overcoming the stringent atmospheric requirements and unsuitability for large-area production of the traditional spin coating method; and the potassium hexafluorophosphate introduced by the method in step S3 can effectively passivate perovskite film defects and inhibit ion migration, thereby reducing the hysteresis effect of the device from the root. Specifically, potassium ions can be embedded in the octahedral interstices of the perovskite lattice, and hexafluorophosphate ions can fill the iodine... The vacancy defects, together with the iodine ion migration in the perovskite lattice, inhibited the migration of iodine ions in the perovskite lattice. The photoelectric conversion efficiency of the final fabricated device was increased from 21.07% to 22.50%, and the hysteresis factor was reduced from 11.8% to 4.1%. The method achieved efficient extraction and transmission of photogenerated electrons through spin-coating an electron transport layer in step S4, and further optimized the contact with the top metal electrode through spin-coating an interface buffer layer. The energy level matching was better, which could block holes and prevent electrode metal diffusion, thus improving the electron collection efficiency and long-term operational stability of the device. The method completed the device structure of the perovskite solar cell by depositing metal electrodes in step S5, forming an effective charge collection and external circuit output path. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the coating process for perovskite solar cells using potassium hexafluorophosphate in this embodiment. Figure 2 This is a schematic diagram of the structure of the low-hysteresis perovskite solar cell in this embodiment; Figure 3 Here are the XRD patterns of the perovskite films with and without potassium hexafluorophosphate in this embodiment; Figure 4 Here are SEM images of potassium hexafluorophosphate with and without added potassium hexafluorophosphate in this embodiment; Figure 5 This is a JV curve diagram of perovskite solar cells with and without potassium hexafluorophosphate in this embodiment; Figure 6 The above are the EQE diagrams of the perovskite solar cells with and without potassium hexafluorophosphate in this embodiment. Figure 7 This is a comparison of the stability of perovskite solar cells with and without potassium hexafluorophosphate in this embodiment in a nitrogen glove box at 20°C. Figure 8 This is a JV curve of the perovskite solar cell module with potassium hexafluorophosphate added in this embodiment. Detailed Implementation

[0017] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0018] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0019] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0020] Please see Figure 1 As shown, this is a schematic flowchart of the coating preparation method for perovskite solar cells using potassium hexafluorophosphate in this embodiment. The method includes: Step S1: Pre-treat the indium tin oxide conductive glass to obtain pre-treated indium tin oxide conductive glass; Step S2: Under the premise of environmental conditions, a hole transport layer is scraped onto the surface of the pretreated indium tin oxide conductive glass to obtain the first indium tin oxide conductive glass. Step S3: Under environmental conditions, a perovskite precursor solution containing potassium hexafluorophosphate is coated onto the surface of the hole transport layer of the first indium tin oxide conductive glass to obtain a substrate. The substrate is then transferred to a vacuum chamber for vacuum treatment. The pressure of the vacuum chamber is 10 Pa, and the vacuum treatment time is 60 seconds to obtain a vacuum-treated substrate. The vacuum-treated substrate is then placed on a hot plate at 120°C for annealing for 10 minutes to attach a perovskite film to the surface of the hole transport layer, thus obtaining the second indium tin oxide conductive glass. Step S4: Spin-coat an electron transport layer on the perovskite film surface of the second indium tin oxide conductive glass to obtain a third indium tin oxide conductive glass; and spin-coat an interface buffer layer on the electron transport layer surface of the third indium tin oxide conductive glass to obtain a fourth indium tin oxide conductive glass. Step S5: Deposit a metal electrode on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass to obtain a low-hysteresis perovskite solar cell.

[0021] Specifically, the method for preparing perovskite solar cells using potassium hexafluorophosphate (PTP) via blade coating is applied in the industry of low-hysteresis perovskite solar cell fabrication. This method uses PTP as an additive to the perovskite precursor solution, which improves the crystallinity of the perovskite film and suppresses the hysteresis effect of blade-coated solar cells. Step S1 provides a clean, smooth, and surface-optimized pre-treated indium tin oxide (ITO) conductive glass for subsequent hole transport layer coating. Step S2 successfully prepares the hole transport layer in an air environment without inert gas protection via blade coating, overcoming the stringent atmospheric requirements and unsuitability for large-area production limitations of traditional spin coating methods. Step S3 introduces PTP, which effectively passivates perovskite film defects and inhibits ion migration, thereby improving the perovskite film's crystallinity and suppressing ion migration. To fundamentally reduce the hysteresis effect of the device, potassium ions can be embedded in the octahedral interstices of the perovskite lattice, and hexafluorophosphate ions can fill iodine vacancies. Together, they inhibit the migration of iodine ions in the perovskite lattice. The photoelectric conversion efficiency of the final fabricated device is increased from 21.07% to 22.50%, and the hysteresis factor is reduced from 11.8% to 4.1%. The method achieves efficient extraction and transmission of photogenerated electrons through spin-coating an electron transport layer in step S4, and further optimizes the contact with the top metal electrode through spin-coating an interface buffer layer, resulting in better energy level matching, blocking holes and preventing electrode metal diffusion, thus improving electron collection efficiency and long-term operational stability of the device. The method completes the device structure of the perovskite solar cell by depositing metal electrodes in step S5, forming an effective charge collection and external circuit output path.

[0022] Specifically, the environmental conditions refer to a normal atmospheric environment, rather than an experimental environment protected by inert gases (such as a nitrogen glove box) or with strict humidity and oxygen control.

[0023] Specifically, the pretreatment of the indium tin oxide conductive glass in step S1 includes: Step S11: Use cleaning agent, deionized water, acetone and ethanol to perform ultrasonic cleaning on indium tin oxide conductive glass to obtain cleaned indium tin oxide conductive glass; Step S12: Use a nitrogen gun to dry the cleaned indium tin oxide conductive glass to obtain dried indium tin oxide conductive glass. Step S13: Use an ultraviolet ozone cleaner to perform ultraviolet ozone cleaning on the dried indium tin oxide conductive glass for 20 minutes to obtain pretreated indium tin oxide conductive glass.

[0024] Specifically, ultrasonic cleaning refers to a process that uses the high-frequency vibration and cavitation effect generated by ultrasonic waves in a cleaning liquid (in this solution, the cleaning agent, deionized water, acetone, and ethanol, in that order) to perform physical and chemical synergistic cleaning on the surface of indium tin oxide conductive glass. Ultraviolet ozone cleaning refers to a method that places the ultrasonically cleaned indium tin oxide conductive glass in an ultraviolet ozone cleaning machine and uses the synergistic effect of short-wave ultraviolet light and ozone to perform deep treatment on the substrate surface.

[0025] Specifically, the material of the hole transport layer in step S2 is poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine].

[0026] Specifically, step S2, which involves coating a hole transport layer onto the pretreated indium tin oxide conductive glass surface, includes: Step S21: Dissolve poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] in a mixed solvent to obtain a pre-solution, and heat and stir the pre-solution at 60°C to obtain a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution. The mixed solvent includes methanol and chloroform, the ratio of methanol to chloroform is 1:1, and the concentration of the mixed solvent is 1 mg / mL. Step S22: Using a blade coating method, a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution is applied to the surface of the pretreated indium tin oxide conductive glass at a first blade coating speed of 10 mm / s to obtain blade-coated indium tin oxide conductive glass, wherein the gap between the blade and the pretreated indium tin oxide conductive glass is 200 μm. Step S23: Place the coated indium tin oxide conductive glass on a hot plate at 100°C and anneal for 10 minutes to obtain the first indium tin oxide conductive glass.

[0027] Specifically, the scraping method refers to a large-area coating technology that uses a controlled-moving scraper to evenly spread a solution on the substrate surface to form a wet film. The heating and stirring refers to a unit operation in which the material is placed under controlled temperature conditions and subjected to mechanical or magnetic disturbance to achieve rapid and uniform dissolution, mixing or reaction. The hot stage refers to a flat-plate heat treatment device with precise temperature control and uniform heating functions. The annealing refers to a heat treatment process in which the coated wet film or solid film is placed in a specific temperature field provided by the hot stage and held for a specified time to drive the film to undergo physical and chemical transformations, ultimately obtaining the target functional properties.

[0028] Specifically, the preparation method of the perovskite precursor solution containing potassium hexafluorophosphate in step S3 includes: Step S31: Dissolve 21.84 mg of cesium iodide, 645.4 mg of lead iodide, 226.35 mg of formamidinium iodide, 5.8 mg of lead chloride, and 1.0 mg to 2.0 mg of potassium hexafluorophosphate in 1 mL of a mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone to obtain an initial mixed solvent, wherein the volume ratio of N,N-dimethylformamide to N-methyl-2-pyrrolidone is 5:1. Step S31: Stir the initial mixed solvent thoroughly to obtain a perovskite precursor solution containing potassium hexafluorophosphate.

[0029] Specifically, thorough stirring refers to a stirring operation that uses continuous mechanical or magnetic disturbance to bring the solution system to a uniform and stable state at the molecular / ionic level.

[0030] Specifically, the coating parameters for applying the perovskite precursor solution containing potassium hexafluorophosphate to the hole transport layer surface of the first indium tin oxide conductive glass in step S3 include: applying the perovskite precursor solution containing potassium hexafluorophosphate to the hole transport layer surface of the first indium tin oxide conductive glass at a second coating speed of 9 mm / s, and the gap between the hole transport layer and the scraper is 250 μm.

[0031] Specifically, step S4, which involves spin-coating an electron transport layer onto the perovskite thin film surface of the second indium tin oxide conductive glass to obtain the third indium tin oxide conductive glass, includes: Step S411: Dissolve the electron transport material [6,6]-phenyl-C61-butyrate methyl ester in chlorobenzene and stir thoroughly to obtain an electron transport spin-coating solution with a concentration of 22 mg / mL. In step S412, the electron transport spin coating solution is spin-coated onto the surface of the perovskite thin film at a spin coating speed of 3000 rpm for 30 seconds to obtain the third indium tin oxide conductive glass.

[0032] Specifically, spin coating refers to a coating technology that uses centrifugal force generated by high-speed rotation to evenly spread a solution dropped into the center of a substrate and ultimately form an ultra-thin, uniform solid film.

[0033] Specifically, step S4, which involves spin-coating an interface buffer layer onto the electron transport layer surface of the third indium tin oxide conductive glass to obtain the fourth indium tin oxide conductive glass, includes: Step S421: Dissolve the interface buffer material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline in isopropanol and stir thoroughly at 60°C to obtain an interface buffer spin-coating solution with a concentration of 0.5 mg / mL. Step S422: The interface buffer spin coating solution is spin-coated onto the surface of the electron transport layer at a spin coating speed of 6000 rpm for 30 seconds to obtain the fourth indium tin oxide conductive glass.

[0034] Specifically, step S5, which involves depositing a metal electrode on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass to obtain a low-hysteresis perovskite solar cell, includes: Step S51: Select a metal electrode material; Step S52: The metal electrode material is deposited on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass using a vacuum deposition machine, thereby forming a metal electrode on the surface of the interface buffer layer to obtain a low-hysteresis perovskite solar cell. The electrode area of ​​the metal electrode is 0.09 cm². 2 .

[0035] Specifically, the vacuum coating machine refers to a specialized device that, in a high vacuum environment, transforms solid metal materials into a gas phase and re-condenses them onto the substrate surface through physical vapor deposition, thereby forming a dense, uniform, and pure metal film. The metal electrode materials include silver, aluminum, and gold.

[0036] Specifically, the parameters of the vacuum coating machine include: a vacuum degree of 6 × 10⁻⁶. -4 Pa, evaporation rate is 0.1 nm / s. Example

[0037] The potassium hexafluorophosphate content in the mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone is 1.0 mg; The preparation method is as follows: The indium tin oxide conductive glass was ultrasonically cleaned using cleaning agent, deionized water, acetone, and ethanol to obtain cleaned indium tin oxide conductive glass. The cleaned indium tin oxide conductive glass was then dried using a nitrogen gun to obtain dried indium tin oxide conductive glass. Finally, the dried indium tin oxide conductive glass was cleaned using an ultraviolet ozone cleaner for 20 minutes to obtain pretreated indium tin oxide conductive glass. Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] was dissolved in a mixed solvent to obtain a pretreatment solution. The pretreatment solution was heated and stirred at 60°C to obtain a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution. The mixed solvent included methanol and chloroform in a 1:1 ratio. The concentration of the mixed solvent was 1 mg / mL. The poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution was applied to the surface of the pretreated indium tin oxide conductive glass using a blade coating method at a first coating speed of 10 mm / s to obtain a blade-coated indium tin oxide conductive glass. The gap between the blade and the pretreated indium tin oxide conductive glass was 200 μm. The blade-coated indium tin oxide conductive glass was then annealed on a hot plate at 100°C for 10 minutes to obtain the first indium tin oxide conductive glass. 21.84 mg of cesium iodide, 645.4 mg of lead iodide, 226.35 mg of formamidinium iodide, 5.8 mg of lead chloride, and 1.0 mg of potassium hexafluorophosphate were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone to obtain an initial mixed solvent, wherein the volume ratio of N,N-dimethylformamide to N-methyl-2-pyrrolidone was 5:1. The initial mixed solvent was stirred thoroughly to obtain a perovskite precursor solution containing potassium hexafluorophosphate. The solution was then applied at a second coating speed of 9 mm / s during the first... A perovskite precursor solution containing potassium hexafluorophosphate is coated onto the surface of the hole transport layer of indium tin oxide conductive glass. The gap between the hole transport layer and the scraper is 250 μm to obtain a substrate. The substrate is then transferred to a vacuum chamber for vacuum treatment. The pressure of the vacuum chamber is 10 Pa and the vacuum treatment time is 60 seconds to obtain a vacuum-treated substrate. The vacuum-treated substrate is then placed on a hot plate at 120°C and annealed for 10 minutes to allow a perovskite film to adhere to the surface of the hole transport layer, thus obtaining a second indium tin oxide conductive glass. The electron transport material [6,6]-phenyl-C61-butyrate methyl ester was dissolved in chlorobenzene and stirred thoroughly to obtain an electron transport spin-coating solution with a concentration of 22 mg / mL. The electron transport spin-coating solution was spin-coated onto the surface of the perovskite film at a spin-coating speed of 3000 rpm for 30 seconds to obtain indium tin oxide conductive glass. The interface buffer material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was dissolved in isopropanol and stirred thoroughly at 60°C to obtain an interface buffer spin-coating solution with a concentration of 0.5 mg / mL. The interface buffer spin-coating solution was spin-coated onto the surface of the electron transport layer at a spin-coating speed of 6000 rpm for 30 seconds to obtain indium tin oxide conductive glass. Using a vacuum coating machine at 6×10 -4 The silver metal electrode is deposited on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass at a vacuum of Pa and an evaporation rate of 0.1 nm / s, thereby forming a silver metal electrode on the surface of the interface buffer layer, resulting in a low-hysteresis perovskite solar cell. The electrode area of ​​the metal electrode is 0.09 cm². 2 . Example

[0038] The potassium hexafluorophosphate content in the mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone is 1.5 mg; The preparation method is as follows: The indium tin oxide conductive glass was ultrasonically cleaned using cleaning agent, deionized water, acetone, and ethanol to obtain cleaned indium tin oxide conductive glass. The cleaned indium tin oxide conductive glass was then dried using a nitrogen gun to obtain dried indium tin oxide conductive glass. Finally, the dried indium tin oxide conductive glass was cleaned using an ultraviolet ozone cleaner for 20 minutes to obtain pretreated indium tin oxide conductive glass. Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] was dissolved in a mixed solvent to obtain a pretreatment solution. The pretreatment solution was heated and stirred at 60°C to obtain a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution. The mixed solvent included methanol and chloroform in a 1:1 ratio. The concentration of the mixed solvent was 1 mg / mL. The poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution was applied to the surface of the pretreated indium tin oxide conductive glass using a blade coating method at a first coating speed of 10 mm / s to obtain a blade-coated indium tin oxide conductive glass. The gap between the blade and the pretreated indium tin oxide conductive glass was 200 μm. The blade-coated indium tin oxide conductive glass was then annealed on a hot plate at 100°C for 10 minutes to obtain the first indium tin oxide conductive glass. 21.84 mg of cesium iodide, 645.4 mg of lead iodide, 226.35 mg of formamidinium iodide, 5.8 mg of lead chloride, and 1.5 mg of potassium hexafluorophosphate were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone to obtain an initial mixed solvent, wherein the volume ratio of N,N-dimethylformamide to N-methyl-2-pyrrolidone was 5:1. The initial mixed solvent was stirred thoroughly to obtain a perovskite precursor solution containing potassium hexafluorophosphate. The solution was then applied at a second coating speed of 9 mm / s. A perovskite precursor solution containing potassium hexafluorophosphate is coated onto the surface of the hole transport layer of indium tin oxide conductive glass. The gap between the hole transport layer and the scraper is 250 μm to obtain a substrate. The substrate is then transferred to a vacuum chamber for vacuum treatment. The pressure of the vacuum chamber is 10 Pa and the vacuum treatment time is 60 seconds to obtain a vacuum-treated substrate. The vacuum-treated substrate is then placed on a hot plate at 120°C and annealed for 10 minutes to allow a perovskite film to adhere to the surface of the hole transport layer, thus obtaining a second indium tin oxide conductive glass. The electron transport material [6,6]-phenyl-C61-butyrate methyl ester was dissolved in chlorobenzene and stirred thoroughly to obtain an electron transport spin-coating solution with a concentration of 22 mg / mL. The electron transport spin-coating solution was spin-coated onto the surface of the perovskite film at a spin-coating speed of 3000 rpm for 30 seconds to obtain indium tin oxide conductive glass. The interface buffer material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was dissolved in isopropanol and stirred thoroughly at 60°C to obtain an interface buffer spin-coating solution with a concentration of 0.5 mg / mL. The interface buffer spin-coating solution was spin-coated onto the surface of the electron transport layer at a spin-coating speed of 6000 rpm for 30 seconds to obtain indium tin oxide conductive glass. Using a vacuum coating machine at 6×10 -4 The silver metal electrode is deposited on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass at a vacuum of Pa and an evaporation rate of 0.1 nm / s, thereby forming a silver metal electrode on the surface of the interface buffer layer, resulting in a low-hysteresis perovskite solar cell. The electrode area of ​​the metal electrode is 0.09 cm². 2 . Example

[0039] The preparation method is as follows: The potassium hexafluorophosphate content in the mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone is 2.0 mg; The indium tin oxide conductive glass was ultrasonically cleaned using cleaning agent, deionized water, acetone, and ethanol to obtain cleaned indium tin oxide conductive glass. The cleaned indium tin oxide conductive glass was then dried using a nitrogen gun to obtain dried indium tin oxide conductive glass. Finally, the dried indium tin oxide conductive glass was cleaned using an ultraviolet ozone cleaner for 20 minutes to obtain pretreated indium tin oxide conductive glass. Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] was dissolved in a mixed solvent to obtain a pretreatment solution. The pretreatment solution was heated and stirred at 60°C to obtain a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution. The mixed solvent included methanol and chloroform in a 1:1 ratio. The concentration of the mixed solvent was 1 mg / mL. The poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution was applied to the surface of the pretreated indium tin oxide conductive glass using a blade coating method at a first coating speed of 10 mm / s to obtain a blade-coated indium tin oxide conductive glass. The gap between the blade and the pretreated indium tin oxide conductive glass was 200 μm. The blade-coated indium tin oxide conductive glass was then annealed on a hot plate at 100°C for 10 minutes to obtain the first indium tin oxide conductive glass. 21.84 mg of cesium iodide, 645.4 mg of lead iodide, 226.35 mg of formamidinium iodide, 5.8 mg of lead chloride, and 2.0 mg of potassium hexafluorophosphate were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone to obtain an initial mixed solvent, wherein the volume ratio of N,N-dimethylformamide to N-methyl-2-pyrrolidone was 5:1. The initial mixed solvent was stirred thoroughly to obtain a perovskite precursor solution containing potassium hexafluorophosphate. The solution was then applied at a second coating speed of 9 mm / s. A perovskite precursor solution containing potassium hexafluorophosphate is coated onto the surface of the hole transport layer of indium tin oxide conductive glass. The gap between the hole transport layer and the scraper is 250 μm to obtain a substrate. The substrate is then transferred to a vacuum chamber for vacuum treatment. The pressure of the vacuum chamber is 10 Pa and the vacuum treatment time is 60 seconds to obtain a vacuum-treated substrate. The vacuum-treated substrate is then placed on a hot plate at 120°C and annealed for 10 minutes to allow a perovskite film to adhere to the surface of the hole transport layer, thus obtaining a second indium tin oxide conductive glass. The electron transport material [6,6]-phenyl-C61-butyrate methyl ester was dissolved in chlorobenzene and stirred thoroughly to obtain an electron transport spin-coating solution with a concentration of 22 mg / mL. The electron transport spin-coating solution was spin-coated onto the surface of the perovskite film at a spin-coating speed of 3000 rpm for 30 seconds to obtain indium tin oxide conductive glass. The interface buffer material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was dissolved in isopropanol and stirred thoroughly at 60°C to obtain an interface buffer spin-coating solution with a concentration of 0.5 mg / mL. The interface buffer spin-coating solution was spin-coated onto the surface of the electron transport layer at a spin-coating speed of 6000 rpm for 30 seconds to obtain indium tin oxide conductive glass. Using a vacuum coating machine at 6×10 -4 The silver metal electrode is deposited on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass at a vacuum of Pa and an evaporation rate of 0.1 nm / s, thereby forming a silver metal electrode on the surface of the interface buffer layer, resulting in a low-hysteresis perovskite solar cell. The electrode area of ​​the metal electrode is 0.09 cm². 2 . Example

[0040] This embodiment is a low-hysteresis perovskite solar cell array with a monolithic series structure; The preparation method is as follows: P1 laser scribing of ITO conductive glass: P1 scribing was performed on indium tin oxide conductive glass (2.89 cm * 2.89 cm) using a laser etching machine. The scribing speed was 200 mm / s, the laser frequency was 50 kHz, the laser power was 12 W, and the scribing width was approximately 40 micrometers. The indium tin oxide conductive glass was ultrasonically cleaned using cleaning agent, deionized water, acetone, and ethanol to obtain cleaned indium tin oxide conductive glass. The cleaned indium tin oxide conductive glass was then dried using a nitrogen gun to obtain dried indium tin oxide conductive glass. Finally, the dried indium tin oxide conductive glass was cleaned using an ultraviolet ozone cleaner for 20 minutes to obtain pretreated indium tin oxide conductive glass. Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] was dissolved in a mixed solvent to obtain a pretreatment solution. The pretreatment solution was heated and stirred at 60°C to obtain a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution. The mixed solvent included methanol and chloroform in a 1:1 ratio. The concentration of the mixed solvent was 1 mg / mL. The poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution was applied to the surface of the pretreated indium tin oxide conductive glass using a blade coating method at a first coating speed of 10 mm / s to obtain a blade-coated indium tin oxide conductive glass. The gap between the blade and the pretreated indium tin oxide conductive glass was 200 μm. The blade-coated indium tin oxide conductive glass was then annealed on a hot plate at 100°C for 10 minutes to obtain the first indium tin oxide conductive glass. 21.84 mg of cesium iodide, 645.4 mg of lead iodide, 226.35 mg of formamidinium iodide, 5.8 mg of lead chloride, and 2.0 mg of potassium hexafluorophosphate were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone to obtain an initial mixed solvent, wherein the volume ratio of N,N-dimethylformamide to N-methyl-2-pyrrolidone was 5:1. The initial mixed solvent was stirred thoroughly to obtain a perovskite precursor solution containing potassium hexafluorophosphate. The solution was then applied at a second coating speed of 9 mm / s. A perovskite precursor solution containing potassium hexafluorophosphate is coated onto the surface of the hole transport layer of indium tin oxide conductive glass. The gap between the hole transport layer and the scraper is 250 μm to obtain a substrate. The substrate is then transferred to a vacuum chamber for vacuum treatment. The pressure of the vacuum chamber is 10 Pa and the vacuum treatment time is 60 seconds to obtain a vacuum-treated substrate. The vacuum-treated substrate is then placed on a hot plate at 120°C and annealed for 10 minutes to allow a perovskite film to adhere to the surface of the hole transport layer, thus obtaining a second indium tin oxide conductive glass. The electron transport material [6,6]-phenyl-C61-butyrate methyl ester was dissolved in chlorobenzene and stirred thoroughly to obtain an electron transport spin-coating solution with a concentration of 22 mg / mL. The electron transport spin-coating solution was spin-coated onto the surface of the perovskite film at a spin-coating speed of 3000 rpm for 30 seconds to obtain indium tin oxide conductive glass. The interface buffer material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was dissolved in isopropanol and stirred thoroughly at 60°C to obtain an interface buffer spin-coating solution with a concentration of 0.5 mg / mL. The interface buffer spin-coating solution was spin-coated onto the surface of the electron transport layer at a spin-coating speed of 6000 rpm for 30 seconds to obtain indium tin oxide conductive glass. P2 laser scribing of indium tin oxide conductive glass: P2 scribing of indium tin oxide conductive glass was performed using a laser etching machine with a wavelength of 532 nm green light, a scribing speed of 200 mm / s, a laser frequency of 100 kHz, a laser power of 4 W, and a scribing width of approximately 90 micrometers. Using a vacuum coating machine at 6×10 -4 The silver metal electrode is deposited on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass at a vacuum of Pa and an evaporation rate of 0.1 nm / s, thereby forming a silver metal electrode on the surface of the interface buffer layer and obtaining a low-hysteresis perovskite solar cell. The electrode area of ​​the metal electrode is 0.09 cm². 2 ; P3 laser scribing of silver metal electrodes: P3 scribing of silver metal electrodes was performed using a laser etching machine with a wavelength of 532 nm green light, a scribing speed of 200 mm / s, a laser frequency of 50 kHz, a laser power of 6 W, and a scribing width of approximately 50 micrometers. P4 laser edge cleaning of silver metal electrodes: P4 edge cleaning of silver metal electrodes is performed using a laser etching machine with a wavelength of 532 nm green light, a scribing speed of 200 mm / s, a laser frequency of 50 kHz, a laser power of 6 W, and an edge cleaning width of 5 mm. The monolithic series-connected low-hysteresis perovskite solar cell array comprises five sub-cells, each 4 mm wide and 1.89 mm long, with a module aperture area of ​​3.78 cm². 2 .

[0041] The sub-cell refers to a single low-hysteresis perovskite solar cell.

[0042] Comparative Example 1: No potassium hexafluorophosphate added; The preparation method is as follows: The indium tin oxide conductive glass was ultrasonically cleaned using cleaning agent, deionized water, acetone, and ethanol to obtain cleaned indium tin oxide conductive glass. The cleaned indium tin oxide conductive glass was then dried using a nitrogen gun to obtain dried indium tin oxide conductive glass. Finally, the dried indium tin oxide conductive glass was cleaned using an ultraviolet ozone cleaner for 20 minutes to obtain pretreated indium tin oxide conductive glass. Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] was dissolved in a mixed solvent to obtain a pretreatment solution. The pretreatment solution was heated and stirred at 60°C to obtain a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution. The mixed solvent included methanol and chloroform in a 1:1 ratio. The concentration of the mixed solvent was 1 mg / mL. The poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution was applied to the surface of the pretreated indium tin oxide conductive glass using a blade coating method at a first coating speed of 10 mm / s to obtain a blade-coated indium tin oxide conductive glass. The gap between the blade and the pretreated indium tin oxide conductive glass was 200 μm. The blade-coated indium tin oxide conductive glass was then annealed on a hot plate at 100°C for 10 minutes to obtain the first indium tin oxide conductive glass. 21.84 mg of cesium iodide, 645.4 mg of lead iodide, 226.35 mg of formamidinium iodide, and 5.8 mg of lead chloride were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone to obtain an initial mixed solvent, wherein the volume ratio of N,N-dimethylformamide to N-methyl-2-pyrrolidone was 5:1. The initial mixed solvent was stirred thoroughly to obtain a perovskite precursor solution containing potassium hexafluorophosphate. This precursor solution was then applied to the first indium tin oxide substrate at a second coating speed of 9 mm / s. A perovskite precursor solution containing potassium hexafluorophosphate is coated onto the surface of the hole transport layer of the electro-glass. The gap between the hole transport layer and the scraper is 250 μm to obtain a substrate. The substrate is then transferred to a vacuum chamber for vacuum treatment. The pressure of the vacuum chamber is 10 Pa, and the vacuum treatment time is 60 seconds to obtain a vacuum-treated substrate. The vacuum-treated substrate is then placed on a hot plate at 120°C and annealed for 10 minutes to allow a perovskite film to adhere to the surface of the hole transport layer, thus obtaining a second indium tin oxide conductive glass. The electron transport material [6,6]-phenyl-C61-butyrate methyl ester was dissolved in chlorobenzene and stirred thoroughly to obtain an electron transport spin-coating solution with a concentration of 22 mg / mL. The electron transport spin-coating solution was spin-coated onto the surface of the perovskite film at a spin-coating speed of 3000 rpm for 30 seconds to obtain indium tin oxide conductive glass. The interface buffer material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was dissolved in isopropanol and stirred thoroughly at 60°C to obtain an interface buffer spin-coating solution with a concentration of 0.5 mg / mL. The interface buffer spin-coating solution was spin-coated onto the surface of the electron transport layer at a spin-coating speed of 6000 rpm for 30 seconds to obtain indium tin oxide conductive glass. Using a vacuum coating machine at 6×10 -4 The silver metal electrode is deposited on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass at a vacuum of Pa and an evaporation rate of 0.1 nm / s, thereby forming a silver metal electrode on the surface of the interface buffer layer, resulting in a perovskite solar cell. The electrode area of ​​the metal electrode is 0.09 cm². 2 Table 1 is a comparison table of photovoltaic parameters for the low-hysteresis perovskite solar cells prepared in Examples 1, 2, and 3 and Comparative Example 1 under AM 1.5G standard sunlight irradiation. ; Among them, V OC J represents the open-circuit voltage. SCrepresents the short-circuit current density, FF represents the fill factor, PCE represents the photoelectric conversion efficiency, and HI represents the hysteresis factor.

[0043] As shown in Table 1, the photoelectric conversion efficiency of the battery is low at only 21.07% without the addition of potassium hexafluorophosphate, and it has a high hysteresis factor of 11.8%. After adding 1-2 mg / mL of potassium hexafluorophosphate, the photoelectric conversion efficiency of the battery is improved, and the hysteresis factor is also significantly reduced.

[0044] Table 2 shows the performance test results of the low-hysteresis perovskite solar cell array with a monolithic tandem structure prepared in Example 4 under AM 1.5G standard sunlight irradiation: ; Table 2 shows the aperture area of ​​3.78 cm². 2 The PCE of the low-hysteresis perovskite solar cell array with monolithic tandem structure is very close between forward and reverse scans, and the hysteresis factor is only 0.7%, indicating that the hysteresis effect has been significantly resolved.

[0045] Please participate Figure 2 The diagram shown is a schematic representation of the low-hysteresis perovskite solar cell in this embodiment. 1 is an indium tin oxide conductive glass, 2 is a hole transport layer, 3 is a perovskite thin film, 4 is an electron transport layer, 5 is an interface buffer layer, and 6 is a metal electrode. The hole transport layer 2 covers the upper surface of the indium tin oxide conductive glass 1. The perovskite thin film 3 is attached to the upper surface of the hole transport layer 2. The electron transport layer 4 is spin-coated onto the upper surface of the perovskite thin film 3. The interface buffer layer 5 is spin-coated onto the upper surface of the electron transport layer 4. The metal electrode 6 is deposited on the upper surface of the interface buffer layer 5.

[0046] Please see Figure 3 As shown, the XRD patterns of the perovskite films with and without potassium hexafluorophosphate in this embodiment are shown. The perovskite film with added potassium hexafluorophosphate exhibits a significantly enhanced diffraction peak at 14°, indicating an improvement in the film's crystallinity. Furthermore, the shift of the diffraction peak to lower angles indicates lattice expansion, which is due to potassium ions occupying interstitial sites in the lattice.

[0047] Please see Figure 4 As shown, this is a SEM image of the film with and without potassium hexafluorophosphate in this embodiment. The grain size of the film with potassium hexafluorophosphate is increased, which helps to reduce bulk recombination and promote the transport of charge carriers in the film.

[0048] Please see Figure 5 As shown, this is a JV curve diagram of the perovskite solar cells with and without potassium hexafluorophosphate in this embodiment. The JV of the device is... SC There has been an improvement, and the lag has been greatly reduced.

[0049] Please see Figure 6 As shown, this is the EQE graph of the perovskite solar cell with and without potassium hexafluorophosphate in this embodiment. The perovskite solar cell with potassium hexafluorophosphate shows improved external quantum efficiency in the 300-800 nm range, and the integrated current density increases from 22.75 mA / cm². 2 Increased to 23.44 mA / cm 2 .

[0050] Please see Figure 7 As shown, this is a comparison of the stability of perovskite solar cells with and without potassium hexafluorophosphate in this embodiment in a nitrogen glove box at 20°C. After 500 hours of storage, the perovskite solar cell without potassium hexafluorophosphate only maintained 81% of its initial efficiency, while the perovskite solar cell with potassium hexafluorophosphate maintained more than 95% of its initial efficiency.

[0051] Please see Figure 8 As shown, it is the JV curve of the perovskite solar cell module with potassium hexafluorophosphate added in this embodiment. The forward and reverse scan curves of the module are almost overlapping, indicating that the hysteresis effect has almost completely disappeared.

[0052] Specifically, the perovskite solar cell with added potassium hexafluorophosphate refers to the low-hysteresis perovskite solar cell in Examples 1, 2 and 3, the perovskite solar cell without added potassium hexafluorophosphate refers to the perovskite solar cell in Comparative Example 1, and the perovskite solar cell module with added potassium hexafluorophosphate refers to the low-hysteresis perovskite solar cell array with monolithic series structure in Example 4.

[0053] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a perovskite solar cell using potassium hexafluorophosphate by doctor blading, characterized by, The method comprises the following steps: S1, pretreating the indium tin oxide conductive glass to obtain pretreated indium tin oxide conductive glass; S2, under the premise of environmental conditions, coating a hole transport layer on the surface of the pretreated indium tin oxide conductive glass by scraping to obtain first indium tin oxide conductive glass; S3, under the premise of environmental conditions, coating a perovskite precursor solution containing potassium hexafluorophosphate on the surface of the hole transport layer of the first indium tin oxide conductive glass by scraping to obtain a substrate, and transferring the substrate into a vacuum cavity for vacuumizing treatment, the pressure of the vacuum cavity is 10 Pa, the treatment time of the vacuumizing treatment is 60 seconds, to obtain a vacuumized substrate, and placing the vacuumized substrate on a hot stage at 120 DEG C for annealing for 10 minutes, so that a perovskite film is attached to the surface of the hole transport layer, to obtain second indium tin oxide conductive glass; S4, coating an electron transport layer on the surface of the perovskite film of the second indium tin oxide conductive glass by spin coating to obtain third indium tin oxide conductive glass, and coating an interface buffer layer on the surface of the electron transport layer of the third indium tin oxide conductive glass by spin coating to obtain fourth indium tin oxide conductive glass; S5, depositing a metal electrode on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass to obtain a perovskite solar cell with low hysteresis. 2.The method of claim 1, wherein the method is characterized by, The pretreatment of the indium tin oxide conductive glass in the step S1 comprises the following steps: S11, ultrasonic cleaning the indium tin oxide conductive glass by using cleaning agent, deionized water, acetone and ethanol to obtain cleaned indium tin oxide conductive glass; S12, drying the cleaned indium tin oxide conductive glass by using a nitrogen gun to obtain dried indium tin oxide conductive glass; S13, ultraviolet ozone cleaning the dried indium tin oxide conductive glass by using an ultraviolet ozone cleaning machine, the cleaning time is 20 minutes, to obtain pretreated indium tin oxide conductive glass. 3.The method of claim 1, wherein the method is characterized by, The material of the hole transport layer in the step S2 is poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]. 4.The method of claim 3, wherein the method is characterized by, The step S2 of coating the hole transport layer on the surface of the pretreated indium tin oxide conductive glass by scraping comprises the following steps: S21, dissolving poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] in a mixed solvent to obtain a pre-solution, and heating and stirring the pre-solution at 60 DEG C to obtain a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution, wherein the mixed solvent comprises methanol and chloroform, the ratio of methanol to chloroform is 1:1, and the concentration of the mixed solvent is 1 mg / mL; S22, coating the poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] solution on the surface of the pretreated indium tin oxide conductive glass by scraping at a first scraping speed of 10 mm / s to obtain scraped indium tin oxide conductive glass, wherein the gap between the scraper and the pretreated indium tin oxide conductive glass is 200 microns; S23, placing the scraped indium tin oxide conductive glass on a hot stage at a temperature of 100 DEG C for annealing for 10 minutes to obtain first indium tin oxide conductive glass. 5.The method of claim 1, wherein the method is characterized by, The preparation method of the perovskite precursor solution containing potassium hexafluorophosphate in the step S3 comprises: In step S31, 21.84 mg of cesium iodide, 645.4 mg of lead iodide, 226.35 mg of formamidinium iodide, 5.8 mg of lead chloride, and 1.0-2.0 mg of potassium hexafluorophosphate are dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide and N-methyl-2-pyrrolidone, to obtain an initial mixed solvent, wherein the volume ratio of N,N-dimethylformamide to N-methyl-2-pyrrolidone is 5:1; In step S31, the initial mixed solvent is stirred to obtain a perovskite precursor solution containing potassium hexafluorophosphate. 6.The method of claim 1, wherein the method is characterized by, The squeegee parameters for squeegeeing the perovskite precursor solution containing potassium hexafluorophosphate on the surface of the hole transport layer of the first indium tin oxide conductive glass in the step S3 comprise: squeegeeing the perovskite precursor solution containing potassium hexafluorophosphate on the surface of the hole transport layer of the first indium tin oxide conductive glass at a second squeegee speed of 9 mm / s, and the gap between the hole transport layer and the squeegee is 250 μm. 7.The method of claim 1, wherein the method is characterized by, The step S4 comprises: In step S411, an electron transport material [6,6]-phenyl-C61-butyric acid methyl ester is dissolved in chlorobenzene and stirred to obtain an electron transport spin-coating solution, and the concentration of the electron transport spin-coating solution is 22 mg / mL; In step S412, the electron transport spin-coating solution is spin-coated on the surface of the perovskite film by a spin-coating method at a spin-coating speed of 3000 rpm, and the spin-coating time is 30 seconds, to obtain a third indium tin oxide conductive glass. 8.The method of claim 1, wherein the method is characterized by, The step S4 comprises: In step S421, an interface buffer material 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline is dissolved in isopropanol and stirred at 60°C under heating to obtain an interface buffer spin-coating solution, and the concentration of the interface buffer spin-coating solution is 0.5 mg / mL; In step S422, the interface buffer spin-coating solution is spin-coated on the surface of the electron transport layer by a spin-coating method at a spin-coating speed of 6000 rpm, and the spin-coating time is 30 seconds, to obtain a fourth indium tin oxide conductive glass. 9.The method of claim 1, wherein the method is characterized by, The step S5 comprises: In step S51, a metal electrode material is selected; Step S52, using a vacuum coating machine to deposit the metal electrode material on the surface of the interface buffer layer of the fourth indium tin oxide conductive glass, so that the surface of the interface buffer layer generates a metal electrode, to obtain a low hysteresis perovskite solar cell, wherein the electrode area of the metal electrode is 0.09cm 2 .

10. The method for preparing perovskite solar cells using potassium hexafluorophosphate according to claim 9, characterized in that, The parameters of the vacuum coating machine include: vacuum degree is 6x10 -4 Pa, evaporation rate is 0.1 nm / s.

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