Preparation method and application of three-dimensional star-shaped polyhedral polymer bulk phase modified efficient and stable perovskite solar cell

Abstract

The invention discloses a preparation method and application of a three-dimensional star-shaped polyhedral polymer bulk phase modified efficient and stable perovskite solar cell, and relates to the technical field of solar photovoltaics. The method comprises the following steps: coating a perovskite precursor solution on a substrate for spin-coating operation, dropwise adding an anti-solvent containing a three-dimensional star-shaped polyhedral polymer in the spin-coating process, then continuing spin-coating for 10-20 seconds, and annealing at 100-120 DEG C for 15-30 minutes to obtain the three-dimensional star-shaped polyhedral polymer bulk phase modified efficient and stable perovskite thin film. According to the invention, the perovskite solar cell is prepared based on the bulk phase modification of the three-dimensional star-shaped polyhedral polymer, and the efficiency and stability of the perovskite cell are improved by regulating the modification concentration of the polymer.

Description

Technical Field

[0001] The present invention relates to the technical field of solar photovoltaics, and particularly to a preparation method and application of a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite solar cell. Background Art

[0002] In recent years, the power conversion efficiency of inverted perovskite solar cells has been continuously increasing, and the highest certified efficiency of the device has reached 26.7%. However, due to the crystal structure characteristics of perovskite materials and the difficult-to-precisely-control crystallization process, a large number of defects will inevitably form during the film formation process of the perovskite active layer. These defects can not only trap photo-generated carriers and reduce the power conversion efficiency of the device, but also serve as permeation channels for moisture and oxygen, affecting the long-term operation stability of the device. The current research on perovskite device defect passivation mainly includes additive engineering, component engineering, and interface engineering, etc. (Adv. Mater., 2022, 2108357). The reported modification materials currently include salts, small molecules, and polymers, etc., and these materials have improved the performance of perovskite solar cells to varying degrees. However, due to their high volatility and low thermal decomposition temperature, small molecule additives limit the long-term stability of the device and it is difficult to ensure the stability of perovskite solar cells in harsh environments. Therefore, it is necessary to develop three-dimensional polymer materials with higher stability and more functional groups to modify the device to further improve the power conversion efficiency and long-term stability of the device.

[0003] In terms of perovskite defect modification, the current research mainly focuses on organic small molecules or linear polymers, etc. Suo et al. designed a dimethylphenethylsulfonium iodide salt (DMPESI) to passivate the upper interface of the perovskite film, and the prepared device has excellent stability, and the loss of power conversion efficiency is less than 1% after maximum power point tracking for more than 4500 hours (Nat. Energy., 2024, 172 - 183). Qu et al. proposed a binary synergistic post-treatment strategy of mixing 4-tert-butylbenzylammonium iodide (tBBAI) and phenylpropylammonium iodide (PPAI) and spin-coating them on the surface of perovskite, which improved the crystallinity of the perovskite film and optimized the hole extraction and transport efficiency in the device. The perovskite solar cell after post-treatment achieved a certified power conversion efficiency of 26.0%, and the device still maintained 81% of the initial efficiency after maximum power point tracking for 450 hours (Nat. Commun., 2024, 8620). However, due to their linear structure, the above-mentioned polymers usually show a relatively single defect passivation effect, and it is difficult to expose the passivation groups. Therefore, polymers with a three-dimensional structure can be selected to modify the perovskite bulk defects to better passivate the defects in the perovskite bulk. Summary of the Invention

[0004] In view of the deficiencies in the above-mentioned background art, the present invention provides a preparation method and application of a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite solar cell. This method is first based on the bulk modification of a three-dimensional star-shaped polyhedron polymer to prepare a perovskite solar cell, and by regulating the modification concentration of the polymer, the efficiency and stability of the perovskite cell are improved. In practical applications, it is found that the efficiency of the perovskite device modified by the three-dimensional polymer can reach 25.12%, and it maintains 88.31% of the initial efficiency after aging in air for 5000 hours and 92.25% of the initial efficiency after operating at the maximum power point for 2500 hours. This preparation method of the perovskite solar cell has great commercial prospects and helps to further improve the stability of the perovskite cell.

[0005] The first object of the present invention is to provide a preparation method of a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film, including the following steps: Coat the perovskite precursor solution on a substrate for spin-coating operation, and during the spin-coating process, dropwise add an anti-solvent containing a three-dimensional star-shaped polyhedron polymer, then continue spin-coating for 10 - 20 seconds, and then anneal at 100 - 120 °C for 15 - 30 minutes to obtain a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film; Among them, the three-dimensional star-shaped polyhedron polymer is a three-dimensional star-shaped polyhedron oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer, and its concentration is 0.01 - 0.1 mg / mL.

[0006] Preferably, the perovskite precursor solution is obtained by dissolving cesium iodide, lead bromide, methylammonium hydrobromide, methylammonium hydrochloride, formamidinium hydroiodide, and lead iodide in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide; the anti-solvent is chlorobenzene or ethyl acetate.

[0007] The second object of the present invention is to provide a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film.

[0008] The third object of the present invention is to provide an application of a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film in a solar cell.

[0009] The fourth object of the present invention is to provide a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite solar cell, including a conductive glass, a hole transport layer, a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film, an electron transport layer, and an electrode stacked in sequence; Among them, the hole transport layer includes nickel oxide and [2-(9H-carbazol-9-yl)ethyl]phosphonic acid; The electron transport layer includes [6,6]-phenyl C61 butyric acid methyl ester and fullerene.

[0010] The fifth objective of the present invention is to provide a method for preparing a three-dimensional star-shaped polyhedron polymer phase-modified highly efficient and stable perovskite solar cell, comprising the following steps: Perform surface treatment on the conductive glass; Prepare a hole transport layer on the conductive glass; Prepare a three-dimensional star-shaped polyhedron polymer phase-modified highly efficient and stable perovskite thin film on the three-dimensional polymer layer; Prepare an electron transport layer on the perovskite thin film; Prepare an electrode on the electron transport layer.

[0011] Preferably, preparing a hole transport layer on the conductive glass includes: Drop nickel oxide ink on the conductive glass, and obtain a nickel oxide thin film through spin coating and annealing; Spin coat an ethanol solution of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid on the nickel oxide thin film, and obtain a 2PACz thin film through annealing treatment, thus obtaining the hole transport layer.

[0012] Preferably, preparing an electron transport layer on the perovskite thin film includes: Dissolve [6,6]-phenyl C61 butyric acid methyl ester and fullerene in chlorobenzene to obtain an electron transport layer precursor solution; Drop the electron transport layer precursor solution on the perovskite thin film, and prepare the electron transport layer through spin coating and annealing.

[0013] Preferably, preparing an electrode on the electron transport layer includes: Under vacuum conditions, deposit gold and chromium as electrodes by thermal evaporation.

[0014] The sixth objective of the present invention is to provide an application of a solar cell in the field of photovoltaics.

[0015] Compared with the prior art, the beneficial effects of the present invention are: The present invention provides a method for preparing and an application of a three-dimensional star-shaped polyhedron polymer phase-modified highly efficient and stable perovskite solar cell. The PSAN polymer adopted in the present invention has rich functional groups. There is an interaction between the nitrile group in the PSAN polymer and the undercoordinated lead ions in the perovskite. The electron-rich nitrile group in the PSAN polymer can effectively passivate the uncoordinated Pb atoms and reduce the formation of metallic Pb. After the PSAN polymer additive is introduced into the perovskite layer through an antisolvent, it cannot enter the perovskite lattice, but is distributed at the grain boundaries and upper surface of the perovskite, delays the crystallization of the perovskite by binding with Pb, and forms large grains penetrating the cross section. After the crystallization is completed, it remains in the perovskite layer and continuously exerts a passivation function by acting on the undercoordinated Pb.

[0016] The efficiency of the perovskite device modified by PSAN polymer in the present invention can reach 25.12%, and it maintains 88.31% of the initial efficiency after aging for 5000 hours in air. While the efficiency of the perovskite battery prepared by the conventional method is 22.45%, and it only maintains 61.21% of the initial efficiency after aging for 5000 hours in air. After operating for 2500 hours under continuous standard sunlight irradiation, the photoelectric conversion efficiency of the device modified by PSAN polymer remains at 23.68%, which is equivalent to 92.25% of the initial efficiency, demonstrating excellent long-term stability. This preparation method has broad commercial application prospects and helps to promote the industrial application of perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a perovskite solar cell.

[0018] Figure 2 It is the environmental stability test curve of the perovskite solar cell before and after polymer modification.

[0019] Figure 3 It is the current density-open circuit voltage test curve of the perovskite solar cell before and after polymer modification.

[0020] Figure 4 It is the operation stability test curve of the perovskite solar cell before and after polymer modification. DETAILED DESCRIPTION OF THE INVENTION

[0021] In order to enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and drawings, but the specific embodiments cited shall not be construed as limiting the present invention.

[0022] The purpose of the present invention is to provide a preparation method and application of a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite solar cell. First, a perovskite solar cell is prepared based on the bulk modification of a three-dimensional star polyhedron polymer, and by adjusting the modification concentration of the polymer, the efficiency and stability of the perovskite battery are improved. It is found in practical applications that the efficiency of the perovskite device modified by the three-dimensional polymer can reach 25.12%, and it maintains 88.31% of the initial efficiency after aging for 5000 hours in air, and maintains 92.25% of the initial efficiency after operating for 2500 hours at the maximum power point. This preparation method of the perovskite solar cell has great commercial prospects and helps to further improve the stability of the perovskite battery.

[0023] In order to achieve the above purpose, the first aspect of the present invention provides a preparation method of a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite thin film, including the following steps: The perovskite precursor solution is coated on a substrate for spin-coating. During the spin-coating process, an anti-solvent containing a three-dimensional star-shaped polyhedral polymer is added dropwise. Subsequently, spin-coating is continued for 10 - 20 seconds, and then annealing is carried out at 100 - 120 °C for 15 - 30 minutes to obtain a highly efficient and stable perovskite thin film modified by a three-dimensional star-shaped polyhedral polymer; Among them, the three-dimensional star-shaped polyhedral polymer is a three-dimensional star-shaped polyhedral oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer, and its concentration is 0.01 - 0.1 mg / mL.

[0024] The perovskite precursor solution is obtained by dissolving cesium iodide, lead bromide, methylammonium hydrobromide, methylammonium hydrochloride, formamidinium hydroiodide, and lead iodide in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide. Specifically, the perovskite precursor solution is obtained by dissolving 0.075 mol / L cesium iodide, 0.077 mol / L lead bromide, 0.071 mol / L methylammonium hydrobromide, 0.166 mol / L methylammonium hydrochloride, 1.354 mol / L formamidinium hydroiodide, and 1.573 mol / L lead iodide in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide with a volume ratio of 4:1.

[0025] The anti-solvent is chlorobenzene or ethyl acetate.

[0026] Exemplarily, a method for preparing a highly efficient and stable perovskite thin film modified by a three-dimensional star-shaped polyhedral polymer includes: Spin-coat the perovskite precursor solution at a speed of 1000 rpm for 10 seconds, and then spin-coat at a speed of 5000 rpm for 40 seconds on a 2PACz thin film. 140 μL of anti-solvent chlorobenzene (CB) or 160 μL of anti-solvent ethyl acetate (EA) is quickly added 12 seconds before the operation of spin-coating at a speed of 5000 rpm for 40 seconds is completed. Subsequently, annealing is carried out at 110 °C for 20 minutes; Among them, the three-dimensional star-shaped polyhedral oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer (PSAN) is pre-dissolved in chlorobenzene (CB) or ethyl acetate (EA) solution to obtain a highly efficient and stable perovskite thin film modified by a three-dimensional star-shaped polyhedral polymer.

[0027] The PSAN polymer used in the present invention has rich functional groups. There is an interaction between the nitrile groups in the PSAN polymer and the undercoordinated lead ions in the perovskite. The electron-rich nitrile groups in the PSAN polymer can effectively passivate the uncoordinated Pb atoms and reduce the formation of metallic Pb. After the PSAN polymer additive is introduced into the perovskite layer through an anti-solvent, it cannot enter the perovskite lattice but is distributed at the grain boundaries and the upper surface of the perovskite. By binding with Pb, it delays the perovskite crystallization, forms large grains that penetrate the cross-section, and remains in the perovskite layer after crystallization is completed. By acting with the undercoordinated Pb, it continuously exerts a passivation function.

[0028] The second aspect of the present invention provides a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite thin film.

[0029] The third aspect of the present invention provides an application of a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite thin film in a solar cell.

[0030] The fourth aspect of the present invention provides a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite solar cell, including a conductive glass, a hole transport layer, a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite thin film, an electron transport layer, and an electrode stacked in sequence; Among them, the hole transport layer includes nickel oxide and [2-(9H-carbazol-9-yl)ethyl]phosphonic acid; The electron transport layer includes [6,6]-phenyl C61 butyric acid methyl ester and fullerene.

[0031] The fifth aspect of the present invention provides a preparation method of a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite solar cell, including the following steps: Perform surface treatment on the conductive glass; Prepare a hole transport layer on the conductive glass; Prepare a three-dimensional star polyhedron polymer bulk-modified highly efficient and stable perovskite thin film on the three-dimensional polymer layer; Prepare an electron transport layer on the perovskite thin film; Prepare an electrode on the electron transport layer.

[0032] Among them, preparing a hole transport layer on the conductive glass includes: Drop nickel oxide ink on the conductive glass, and obtain a nickel oxide thin film through spin coating and annealing; Spin coat an ethanol solution of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid on the nickel oxide thin film, and obtain a 2PACz thin film through annealing treatment, thus obtaining the hole transport layer.

[0033] Preparing an electron transport layer on the perovskite thin film includes: Dissolve methyl [6,6]-phenyl C61 butyrate and fullerene in chlorobenzene to obtain an electron transport layer precursor solution; Drop the electron transport layer precursor solution onto the perovskite film, and spin-coat and anneal it to prepare the electron transport layer.

[0034] Prepare an electrode on the electron transport layer, including: depositing gold and chromium as the electrode by thermal evaporation under vacuum conditions.

[0035] It should be noted that the indium tin oxide is used as the conductive glass in the examples.

[0036] Exemplarily, see Figure 1 As shown, a preparation method of a highly efficient and stable perovskite solar cell with three-dimensional star polyhedron polymer bulk modification mainly includes the following steps: Immerse indium tin oxide (ITO) glass in deionized water, add a small amount of cleaning agent and use a brush to remove the oil stain on the surface of the ITO glass, then ultrasonically rinse it with deionized water, acetone and IPA respectively, and finally place it in an ethanol solution for standby.

[0037] Before use, blow-dry the cleaned ITO glass with a nitrogen gun to promote the volatilization of ethanol, and then treat the surface of the ITO glass with a UV-ozone machine for 15 min. Take an appropriate amount of nickel oxide (NiO x ) ink and drop it on the above ITO glass. After a spin-coating process at 3000 rpm for 30 s, anneal it on a heating table at 100 °C for 10 min to obtain the NiO x layer.

[0038] Dissolve 0.5 mg of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) in 1 mL of absolute ethanol, stir it in the dark for more than 12 hours to obtain a uniform 2PACz precursor solution. Transfer the treated substrate to a glove box. On the NiO x film, take 50 μL of the 2PACz precursor solution, spin-coat it at 3000 rpm for 30 seconds, and anneal it at 100 °C for 10 minutes to obtain a uniform 2PACz film.

[0039] Next, the perovskite precursor solution was spin-coated on the 2PACz film at 1000 rpm for 10 s and then at 5000 rpm for 40 s. Twelve seconds before the operation of spin-coating at 5000 rpm for 40 s was completed, 140 μL of the antisolvent chlorobenzene (CB) or 160 μL of the antisolvent ethyl acetate (EA) was quickly added. Subsequently, the ITO glass was transferred to a heating platform and annealed at 110 °C for 20 min. Among them, for the perovskite film modified with three-dimensional star polyhedral oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer (abbreviated as PSAN), the polymer (PSAN, 0.06 mg / mL) was pre-dissolved in chlorobenzene (CB) or ethyl acetate (EA) solution, and then the above steps were repeated to obtain the PSAN-modified perovskite film.

[0040] Subsequently, [6,6]-phenyl C61 butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) were dissolved in chlorobenzene at a mass ratio of 4:1 to prepare an electron transport layer precursor solution with a concentration of 25 mg mL −1 . The solution was stirred at room temperature for at least 12 h and then filtered for use. After that, an appropriate amount of the electron transport layer precursor solution was dropped on the perovskite film and spin-coated at 3000 rpm. After 30 s, it was transferred to a heating platform at 60 °C and annealed for 10 min to obtain the electron transport layer.

[0041] Finally, under a vacuum condition of 2×10 −6 mbar (effective area is 0.1 cm 2 ), 100 nm of gold (Au) and 5 nm of chromium (Cr) were deposited by thermal evaporation to prepare the device.

[0042] The sixth aspect of the present invention provides an application of a solar cell in the photovoltaic field.

[0043] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used can be purchased on the market unless otherwise specified.

[0044] Example 1 A preparation method of a highly efficient and stable perovskite solar cell modified by a three-dimensional star polyhedral polymer bulk phase mainly comprises the following steps: The indium tin oxide (ITO) glass was soaked in deionized water, a small amount of cleaning agent was added, and the oil stain on the surface of the ITO glass was removed with a brush. Then, it was ultrasonically rinsed with deionized water, acetone and IPA respectively, and finally placed in an ethanol solution for standby. Before use, the cleaned ITO glass was purged with a nitrogen gun to promote the volatilization of ethanol, and then the surface of the ITO glass was treated with an ultraviolet-ozone machine for 15 min.

[0045] Take an appropriate amount of nickel oxide (NiO x ) ink and drop it on the above-mentioned ITO glass. After a spin-coating process at 3000 rpm for 30 s, then anneal it on a heating stage at 100 °C for 10 min to obtain the NiO x layer. Dissolve 0.5 mg of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) in 1 mL of absolute ethanol and stir it in the dark for more than 12 hours to obtain a uniform 2PACz precursor solution. Transfer the treated substrate to a glove box. On the NiO x film, take 50 μL of the 2PACz precursor solution and spin-coat it with parameters of 3000 rpm and 30 s, and then anneal it at 100 °C for 10 min to obtain a uniform 2PACz film.

[0046] Next, prepare a perovskite precursor solution containing the following components: 0.075 mol / L cesium iodide, 0.077 mol / L lead bromide, 0.071 mol / L methylammonium hydrobromide, 0.166 mol / L methylammonium hydrochloride, 1.354 mol / L formamidinium hydroiodide, 1.573 mol / L lead iodide, and a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the two solvents is 4:1). Spin-coat the perovskite precursor solution at a speed of 1000 rpm for 10 s, and then spin-coat it at a speed of 5000 rpm for 40 s on the 2PACz film. At the 12th second before the operation is completed, quickly add 160 μL of the antisolvent ethyl acetate (EA). Transfer the ITO glass to a heating platform and anneal it at 110 °C for 20 min. For the perovskite film modified with three-dimensional star-shaped polyhedral oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer (abbreviated as PSAN), first dissolve the polymer (PSAN, 0.06 mg / mL) in chlorobenzene (CB) solution in advance, and then repeat the above steps to obtain the PSAN-modified perovskite film.

[0047] Subsequently, dissolve [6,6]-phenyl-C61-butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) in chlorobenzene according to a mass ratio of 4:1 to prepare an electron transport layer precursor solution with a concentration of 25 mg mL −1 and stir it at room temperature for at least 12 h and then filter it for use. Then, take an appropriate amount of the electron transport layer precursor solution and drop it on the perovskite film. After spin-coating at 3000 rpm for 30 s, transfer it to a heating stage at 60 °C and anneal it for 10 min to obtain the electron transport layer.

[0048] Finally, at 2×10 −6Under a vacuum condition of mbar (effective area: 0.1 cm 2 ), gold (Au) of 100 nm and chromium (Cr) of 5 nm were deposited by thermal evaporation method to fabricate the device.

[0049] Test results: The photoelectric conversion efficiency of the fabricated perovskite solar cell was 25.12%. After aging for 5000 hours in an air environment of 25 °C and 50 ± 5% RH, the cell efficiency was 88.31% of the initial efficiency. Under the condition of continuous standard sunlight intensity irradiation at 45 °C, the encapsulated perovskite solar cell maintained 92.25% of the initial efficiency when operating at the maximum power point for 2500 hours.

[0050] Example 2 A preparation method of a highly efficient and stable perovskite solar cell with three-dimensional star polyhedron polymer bulk modification, the main steps are as follows: The indium tin oxide (ITO) glass was soaked in deionized water, a small amount of cleaning agent was added and the oil stains on the surface of the ITO glass were removed with a brush, then ultrasonic rinsing was carried out with deionized water, acetone and IPA respectively, and finally it was placed in an ethanol solution for standby. Before use, the cleaned ITO glass was purged with a nitrogen gun to promote the volatilization of ethanol, and then the surface of the ITO glass was treated with an ultraviolet-ozone machine for 15 min.

[0051] An appropriate amount of nickel oxide (NiO x ) ink was dropped on the above-mentioned ITO glass. After a spin-coating process at 3000 rpm for 30 s, it was annealed on a heating table at 100 °C for 10 min to obtain the NiO x layer. 0.5 mg of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) was dissolved in 1 mL of absolute ethanol and stirred in the dark for more than 12 hours to obtain a uniform 2PACz precursor solution. The treated substrate was transferred to a glove box. On the NiO x film, 50 μL of the 2PACz precursor solution was taken and spin-coated with parameters of 3000 rpm and 30 seconds, and annealed at 100 °C for 10 minutes to obtain a uniform 2PACz film.

[0052] Next, prepare a perovskite precursor solution containing the following components: 0.075 mol / L cesium iodide, 0.077 mol / L lead bromide, 0.071 mol / L methylammonium hydrobromide, 0.166 mol / L methylammonium hydrochloride, 1.354 mol / L formamidinium hydroiodide, 1.573 mol / L lead iodide, and a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the two solvents is 4:1). Spin-coat the perovskite precursor solution at a speed of 1000 rpm for 10 seconds, and then spin-coat it at a speed of 5000 rpm for 40 seconds on the 2PACz film. At the 12th second before the operation is completed, quickly add 160 μL of the antisolvent ethyl acetate (EA). Transfer the ITO glass to a heating platform and anneal it at 110 °C for 20 minutes. For the perovskite film modified with three-dimensional star-shaped polyhedral oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer (abbreviated as PSAN), first dissolve the polymer (PSAN, 0.00 mg / mL) in chlorobenzene (CB) solution in advance, and then repeat the above steps to obtain the PSAN-modified perovskite film.

[0053] Subsequently, [6,6]-phenyl C61 butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) were dissolved in chlorobenzene according to a mass ratio of 4:1 to prepare an electron transport layer precursor solution with a concentration of 25 mg mL −1 and stirred at least for 12 h at room temperature and then filtered for use. Then, take an appropriate amount of the electron transport layer precursor solution and drop it on the perovskite film, spin-coat it at 3000 rpm, and after 30 s, transfer it to a heating platform at 60 °C and anneal it for 10 min to obtain the electron transport layer.

[0054] Finally, under a vacuum condition of 2×10 −6 mbar (the effective area is 0.1 cm 2 ), deposit 100 nm of gold (Au) and 5 nm of chromium (Cr) by thermal evaporation to prepare the device.

[0055] Test results: The photoelectric conversion efficiency of the prepared perovskite solar cell is 22.45%. After aging for 5000 hours in an air environment at 25 °C and 50 ± 5% RH, the cell efficiency is 61.21% of the initial efficiency. Under the condition of continuous standard sunlight intensity irradiation at 45 °C, the encapsulated perovskite solar cell maintains 60.02% of the initial efficiency when operating at the maximum power point for 2500 hours.

[0056] Example 3 A preparation method of a highly efficient and stable perovskite solar cell modified by a three-dimensional star-shaped polyhedral polymer bulk phase, the main steps are as follows: Immerse indium tin oxide (ITO) glass in deionized water, add a small amount of cleaning agent and use a brush to remove the oil stains on the surface of the ITO glass. Then, perform ultrasonic rinsing with deionized water, acetone, and IPA respectively. Finally, place it in an ethanol solution for standby. Before use, blow-dry the cleaned ITO glass with a nitrogen gun to promote the volatilization of ethanol, and then treat the surface of the ITO glass with an ultraviolet-ozone machine for 15 min.

[0057] Take an appropriate amount of nickel oxide (NiO x ) ink and drop it on the above-mentioned ITO glass. After a spin-coating process at 3000 rpm for 30 s, then anneal it on a heating stage at 100 °C for 10 min to obtain the NiO x layer. Dissolve 0.5 mg of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) in 1 mL of anhydrous ethanol and stir it in the dark for more than 12 hours to obtain a uniform 2PACz precursor solution. Transfer the treated substrate to a glove box. On the NiO x film, take 50 μL of the 2PACz precursor solution and perform spin-coating with parameters of 3000 rpm and 30 s, and then anneal it at 100 °C for 10 min to obtain a uniform 2PACz film.

[0058] Next, prepare a perovskite precursor solution containing the following components: 0.075 mol / L cesium iodide, 0.077 mol / L lead bromide, 0.071 mol / L methylammonium hydrobromide, 0.166 mol / L methylammonium hydrochloride, 1.354 mol / L formamidinium hydroiodide, 1.573 mol / L lead iodide, and a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the two solvents is 4:1). Spin-coat the perovskite precursor solution at a speed of 1000 rpm for 10 s, and then spin-coat it at a speed of 5000 rpm for 40 s on the 2PACz film. At the 12th second before the operation is completed, quickly add 140 μL of the antisolvent chlorobenzene (CB). Transfer the ITO glass to a heating platform and anneal it at 110 °C for 20 min. For the perovskite film modified with three-dimensional star-shaped polyhedral oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer (abbreviated as PSAN), first dissolve the polymer (PSAN, 0.03 mg / mL) in an ethyl acetate (EA) solution in advance, and then repeat the above steps to obtain the PSAN-modified perovskite film.

[0059] Subsequently, dissolve [6,6]-phenyl-C61-butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) in chlorobenzene at a mass ratio of 4:1 to prepare a concentration of 25 mg mL −1The electron transport layer precursor solution is stirred at least for 12 h at room temperature and then filtered for later use. Then, an appropriate amount of the electron transport layer precursor solution is dropped onto the perovskite film and spin-coated at 3000 rpm for 30 s. After that, it is transferred to a heating stage at 60 °C and annealed for 10 min to obtain the electron transport layer.

[0060] Finally, under a vacuum condition of 2×10 −6 mbar (with an effective area of 0.1 cm 2 ), gold (Au) of 100 nm and chromium (Cr) of 5 nm are deposited by thermal evaporation to fabricate the device.

[0061] Test results: The photoelectric conversion efficiency of the fabricated perovskite solar cell is 23.44%. After aging for 5000 hours in an air environment at 25 °C and 50 ± 5% RH, the cell efficiency is 70.56% of the initial efficiency. Under continuous standard sunlight intensity irradiation conditions at 45 °C, the encapsulated perovskite solar cell maintains 72.32% of the initial efficiency when operating at the maximum power point for 2500 hours.

[0062] Example 4 A preparation method of a highly efficient and stable perovskite solar cell with three-dimensional star polyhedron polymer bulk modification, the main steps are as follows: The indium tin oxide (ITO) glass is immersed in deionized water, a small amount of cleaning agent is added, and the oil stains on the surface of the ITO glass are removed with a brush. Then, ultrasonic rinsing is carried out with deionized water, acetone and IPA respectively. Finally, it is placed in an ethanol solution for later use. Before use, the cleaned ITO glass is purged with a nitrogen gun to promote the volatilization of ethanol, and then the surface of the ITO glass is treated with an ultraviolet-ozone machine for 15 min.

[0063] An appropriate amount of nickel oxide (NiO x ) ink is dropped onto the above-mentioned ITO glass. After a spin-coating process at 3000 rpm for 30 s, it is annealed on a heating stage at 100 °C for 10 min to obtain the NiO x layer. 0.5 mg of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) is dissolved in 1 mL of anhydrous ethanol and stirred in the dark for more than 12 hours to obtain a uniform 2PACz precursor solution. The treated substrate is transferred to a glove box. On the NiO x film, 50 μL of the 2PACz precursor solution is taken and spin-coated at 3000 rpm for 30 s, and annealed at 100 °C for 10 min to obtain a uniform 2PACz film.

[0064] Next, prepare a perovskite precursor solution containing the following components: 0.075 mol / L cesium iodide, 0.077 mol / L lead bromide, 0.071 mol / L methylammonium hydrobromide, 0.166 mol / L methylammonium hydrochloride, 1.354 mol / L formamidinium hydroiodide, 1.573 mol / L lead iodide, and a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the two solvents is 4:1). Spin-coat the perovskite precursor solution at a speed of 1000 rpm for 10 seconds, and then spin-coat it at a speed of 5000 rpm for 40 seconds on the 2PACz film. At the 12th second before the operation is completed, quickly add 160 μL of the antisolvent ethyl acetate (EA), transfer the ITO glass to a heating platform, and anneal it at 110 °C for 20 minutes. For the perovskite film modified with three-dimensional star-shaped polyhedral oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer (abbreviated as PSAN), first dissolve the polymer (PSAN, 0.09 mg / mL) in a chlorobenzene (CB) solution in advance, and then repeat the above steps to obtain the PSAN-modified perovskite film.

[0065] Subsequently, dissolve [6,6]-phenyl C61 butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) in chlorobenzene at a mass ratio of 4:1 to prepare an electron transport layer precursor solution with a concentration of 25 mg mL −1 and stir it at room temperature for at least 12 h before filtering for use. Then, take an appropriate amount of the electron transport layer precursor solution and drop it on the perovskite film, spin-coat it at 3000 rpm, and after 30 s, transfer it to a heating platform at 60 °C and anneal it for 10 min to obtain the electron transport layer.

[0066] Finally, under a vacuum condition of 2×10 −6 mbar (the effective area is 0.1 cm 2 ), deposit 100 nm of gold (Au) and 5 nm of chromium (Cr) by thermal evaporation to fabricate the device.

[0067] Test results: The photoelectric conversion efficiency of the fabricated perovskite solar cell is 23.89%. After aging for 5000 hours in an air environment at 25 °C and 50 ± 5% RH, the cell efficiency is 74.27% of the initial efficiency. Under continuous standard sunlight intensity irradiation conditions at 45 °C, the encapsulated perovskite solar cell maintains 75.91% of the initial efficiency when operating at the maximum power point for 2500 hours.

[0068] To illustrate the relevant performance of the solar cell provided by the present invention, it is described in conjunction with the accompanying drawings.

[0069] Figure 1Schematic diagram of a perovskite solar cell. ITO Glass represents an indium tin oxide glass substrate, NiO x represents a nickel oxide layer, 2PACz represents [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, Perovskite represents the perovskite active layer, PSAN represents a three-dimensional star-shaped polyhedral oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer, PCBM + C60 represents the electron transport layer, Cr represents the chromium electrode, and Au represents the gold electrode.

[0070] Figure 2 The environmental stability of the perovskite cells of Example 1 (blue dotted line) and Example 2 (red dotted line) is illustrated. Evolution of the normalized PCE of the perovskite cells before and after PSAN modification in air at dark state, 25 °C, and 50 ± 5% relative humidity. Modifying the perovskite with PSAN results in a significant change in the stability of the perovskite cells before and after modification, indicating that modifying the perovskite film with PSAN effectively improves the environmental stability of the perovskite cells.

[0071] Figure 3 The power conversion efficiency of the perovskite cells of Example 1 (blue dotted line) and Example 2 (red dotted line) is illustrated. Short-circuit current density - open-circuit voltage curves of the perovskite cells before and after PSAN modification. The efficiency of the perovskite cells is significantly improved before and after modification, demonstrating the effectiveness of the three-dimensional star-shaped polymer modification.

[0072] Figure 4 The operational stability of the perovskite cells of Example 1 (blue dotted line) and Example 2 (red dotted line) is illustrated. Operational stability tests of the perovskite cells before and after PSAN polymer modification. After operating for 2500 hours under continuous standard sunlight illumination, the power conversion efficiency of the PSAN polymer-modified device remains at 23.68%, equivalent to 92.25% of the initial efficiency, indicating that the perovskite device can have excellent operational stability after PSAN polymer modification.

[0073] This invention describes the preferred embodiments and their effects. However, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0074] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method for efficiently and stably modifying the bulk phase of a three-dimensional star-shaped polyhedron polymer perovskite thin film, characterized in that, It includes the following steps: Coat the perovskite precursor solution on a substrate and perform a spin-coating operation. During the spin-coating process, add an anti-solvent containing a three-dimensional star-shaped polyhedron polymer dropwise, then continue spin-coating for 10 - 20 seconds, and then anneal at 100 - 120 °C for 15 - 30 minutes to obtain a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film; Among them, the three-dimensional star-shaped polyhedron polymer is a three-dimensional star-shaped polyhedron oligosilsesquioxane-polystyrene-b-polyacrylonitrile polymer, and its concentration is 0.01 - 0.1 mg / mL.

2. The preparation method of the three-dimensional star polyhedron polymer-phase modified highly efficient and stable perovskite thin film according to claim 1, characterized in that The perovskite precursor solution is obtained by dissolving cesium iodide, lead bromide, methylammonium hydrobromide, methylammonium hydrochloride, formamidinium hydroiodide, and lead iodide in a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide; the anti-solvent is chlorobenzene or ethyl acetate.

3. A three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film prepared by the method according to claim 1 or 2.

4. An application of the three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film according to claim 3 in a solar cell.

5. A three-dimensional star-shaped polyhedron polymer phase-modified highly efficient and stable perovskite solar cell, characterized in that, It includes a conductive glass, a hole transport layer, a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film, an electron transport layer, and an electrode stacked in sequence; Among them, the hole transport layer includes nickel oxide and [2-(9H-carbazol-9-yl)ethyl]phosphonic acid; The electron transport layer includes [6,6]-phenyl C61 butyric acid methyl ester and fullerene.

6. A method for preparing a three-dimensional star-shaped polyhedron-aggregated bulk-modified highly efficient and stable perovskite solar cell according to claim 5, characterized in that, It includes the following steps: Perform surface treatment on the conductive glass; Prepare a hole transport layer on the conductive glass; Prepare a three-dimensional star-shaped polyhedron polymer bulk-modified highly efficient and stable perovskite thin film on the three-dimensional polymer layer; Prepare an electron transport layer on the perovskite thin film; Prepare an electrode on the electron transport layer.

7. The preparation method of the three-dimensional star-shaped polyhedron-aggregated object-phase modified highly efficient and stable perovskite solar cell according to claim 6, wherein, Preparing a hole transport layer on the conductive glass includes: Drop nickel oxide ink on the conductive glass, and obtain a nickel oxide thin film through spin-coating and annealing; Spin-coat an ethanol solution of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid on the nickel oxide thin film, and obtain a 2PACz thin film through annealing treatment, thus obtaining the hole transport layer.

8. The preparation method of the three-dimensional star-shaped polyhedron-aggregated and bulk-modified highly efficient and stable perovskite solar cell according to claim 6, wherein, Preparing an electron transport layer on the perovskite thin film includes: Dissolve [6,6]-phenyl C61 butyric acid methyl ester and fullerene in chlorobenzene to obtain an electron transport layer precursor solution; Drop the electron transport layer precursor solution on the perovskite thin film, and obtain the electron transport layer through spin-coating and annealing.

9. The preparation method of the three-dimensional star-shaped polyhedron-aggregated object-phase modified highly efficient and stable perovskite solar cell according to claim 6, wherein, Preparing an electrode on the electron transport layer includes: Under vacuum conditions, deposit gold and chromium as electrodes by thermal evaporation.

10. An application of the solar cell according to claim 5 in the photovoltaic field.

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