Preparation of high-efficiency quasi-two-dimensional perovskite solar cells by fast-drying and slow-growth deposition method

Abstract

The application discloses a high-efficiency quasi-two-dimensional perovskite solar cell prepared by a quick-drying slow-growth deposition method, and comprises, from bottom to top, a substrate, a cathode, a cathode modification layer, an active layer, an anode modification layer and an anode, so as to form the high-efficiency quasi-two-dimensional perovskite solar cell. The active layer is prepared by the quick-drying slow-growth deposition method, and specifically comprises the following steps: GAI, MAI and PbI2 are added into a mixed solvent of ACN and MA / EtOH according to a stoichiometric ratio, NH4SCN and MACl are further added into the mixed solvent, then spin coating and deposition are carried out on the cathode modification layer, and (GA)2(MA) n‑1 Pb n I 3n+1 A quasi-two-dimensional perovskite thin film active layer, wherein n is greater than or equal to 3. The application adopts a simple spin coating process to deposit the quasi-two-dimensional perovskite active layer, avoids a dropwise adding process of an anti-solvent, and realizes a controllable orientation distribution in the active layer and a high-efficiency large-area quasi-two-dimensional perovskite solar cell.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cells, and more specifically to a fast-drying slow-growth deposition method and a high-efficiency quasi-two-dimensional perovskite solar cell prepared using this method. Background Technology

[0002] In recent years, perovskite solar cells have attracted increasing attention in the photovoltaic field due to their high efficiency, flexibility, and low-cost solution processing methods, which has greatly stimulated and accelerated their commercialization process (Science 2022, 377, 531. Nature 2022, 612, 266). Among them, quasi-two-dimensional perovskite solar cells have been proven to be more stable photovoltaic devices than three-dimensional perovskite solar cells due to their advantages such as higher lattice energy and lower ion migration activation energy. However, compared with the currently widely studied three-dimensional perovskite solar cells, their device efficiency still has considerable room for improvement. Therefore, in order to simultaneously meet the requirements of efficiency and stability, researchers are also seeking various measures to improve their device performance. Currently, the primary challenge in fabricating high-performance quasi-two-dimensional perovskite solar cells is to prepare flat films with high crystallinity and vertical orientation.

[0003] Typically, perovskite precursor solutions are mainly composed of high-boiling-point solvents such as dimethyl sulfoxide (DMSO), γ-butyrolactone (GBL), and N-methylpyrrolidone (NMP). This often prolongs solvent evaporation / film drying time and the perovskite crystallization process, which is also prolonged and at higher temperatures, and often results in very rough films. To address these issues, several specific processing methods have been developed, such as vacuum or gas-purged assisted drying, pulsed light sintering, and anti-solvent washing (Joule 2019, 3, 402. Science 2016, 353, 6294. Joule 2018, 2, 1313.). For example, anti-solvent deposition can rapidly extract the "free" solvent from the wet perovskite film, thereby obtaining a smooth and flat perovskite film. However, these methods are cumbersome and difficult to meet the needs of large-area preparation. Therefore, it is still very necessary to develop a simple but effective method to prepare high-quality perovskite films.

[0004] Controlling the composition of the precursor solution is an effective strategy for controlling perovskite crystallization and preparing high-quality, large-area perovskite thin films. The synergistic effect of highly volatile solvents (such as acetonitrile (ACN)) and high-boiling-point solid additives (such as organic molecules, ammonium salts and long-chain polymers, ionic liquids, or solvent coordination) is an effective method for depositing high-quality, large-area perovskite thin films. Compared with the traditional solvent DMF (N,N-dimethylformamide) / DMSO, the use of highly volatile solvents can significantly shorten the film curing time, achieve a rapid nucleation process, and induce the generation of a large number of nuclei, resulting in the deposition of dense, smooth, and pinhole-free large-area perovskite thin films. However, this solvent system often leads to undesirable film morphologies, such as small grain size, porous surfaces, and disordered grains, which negatively impact carrier transport and the performance of related devices. The introduction of high-boiling-point solid additives can mitigate the crystallization process and eliminate these effects by forming Lewis acid-base intermediate adducts or hydrogen bonds. Unfortunately, current research on improving the performance of quasi-two-dimensional perovskite solar cells mainly focuses on defect passivation and interface modification engineering, completely ignoring the potential application of these strategies in the fabrication of high-performance, large-area quasi-two-dimensional perovskite solar cells. Summary of the Invention

[0005] To address the aforementioned technical problems and shortcomings in the field, this invention provides a method for preparing high-efficiency quasi-two-dimensional perovskite solar cells using a fast-drying, slow-growth deposition method. The fast-drying refers to the rapid curing of the quasi-two-dimensional perovskite film using a highly volatile solvent, and the slow-growth refers to the use of specific solid additives to delay the growth of (GA)2(MA). n-1 Pb n I 3n+1 The crystallization of quasi-two-dimensional perovskite crystals enables slow and efficient crystal growth and specific orientation of quasi-two-dimensional perovskites.

[0006] A method for preparing a high-efficiency quasi-two-dimensional perovskite solar cell using a fast-drying, slow-growth deposition method includes: sequentially depositing a substrate, a cathode, a cathode modification layer, an active layer, an anode modification layer, and an anode from bottom to top to form the high-efficiency quasi-two-dimensional perovskite solar cell;

[0007] The active layer is prepared using a fast-drying, slow-growth deposition method, specifically comprising: adding GAI (guanidinium iodide, CAS No.: 19227-70-4), MAI (methylamine iodide, CAS No.: 14965-49-2), and PbI2 (lead iodide) in stoichiometric ratios to a mixed solvent of ACN (acetonitrile) and MA / EtOH (methylamine in ethanol, methylamine / ethanol solution). NH4SCN (ammonium thiocyanate) and MACl (chloromethylamine, methylamine hydrochloride, CAS No.: CH3NH3Cl, CAS No.: 593-51-1) are also added to the mixed solvent. The mixture is then spin-coated onto the cathode modification layer and annealed to obtain (GA)2(MA). n-1 Pb n I 3n+1 The active layer of a quasi-two-dimensional perovskite thin film, where n ≥ 3. For example, when n = 5, the stoichiometric ratio of GAI, MAI, and PbI2 is 2:4:5.

[0008] This invention employs a simple spin-coating process to deposit a quasi-two-dimensional perovskite active layer, avoiding the drop-addition process of anti-solvents, thereby achieving a large-area quasi-two-dimensional perovskite solar cell with controllable orientation distribution and high efficiency in the active layer.

[0009] for (GA)2(MA) n-1 Pb n I 3n+1 The present invention utilizes highly volatile acetonitrile and methylamine / ethanol solution to achieve rapid solution solidification, realizing a rapid nucleation process and inducing a large number of nuclei, ultimately obtaining a dense, smooth, and pinhole-free perovskite film. Furthermore, the present invention introduces high-boiling-point solid additives NH4SCN and CH3NH3Cl, achieving a slow but effective crystal growth step, making (GA)2(MA) n-1 Pb n I 3n+1 The perovskite crystal grains are further enlarged; on the other hand, the introduction of high-boiling-point solid additives NH4SCN and CH3NH3Cl also promotes the perovskite towards the (111) and (202) preferred orientations by delaying crystallization, which is particularly important for quasi-two-dimensional perovskites. Therefore, the quasi-two-dimensional perovskite solar cell obtained in this invention achieves a synergistic improvement in open-circuit voltage, short-circuit current, and fill factor, and its energy conversion efficiency exceeds that of quasi-two-dimensional perovskite solar cells prepared by anti-solvent deposition method, based on (GA)2(MA). n-1 Pb n I 3n+1 (n=5) 1cm 2Quasi-two-dimensional perovskite solar cells achieved a maximum power conversion efficiency of 19.08%, higher than the 15.08% of quasi-two-dimensional perovskite solar cells prepared by the corresponding anti-solvent deposition method. This is also the highest efficiency achieved to date for 1cm... 2 The highest efficiency of quasi-two-dimensional perovskite solar cells.

[0010] In the mixed solvent, the concentration of PbI2 is preferably 0.5–0.7 M, more preferably 0.6 M, to obtain the desired thickness of (GA)2(MA). n-1 Pb n I 3n+1 Quasi-two-dimensional perovskite thin film active layers, for example, with a PbI2 concentration of 0.6 M, can achieve a thickness of approximately 300 nm for (GA)2(MA). n-1 Pb n I 3n+1 The active layer of the quasi-two-dimensional perovskite thin film exhibits excellent conductivity and good light absorption performance at this thickness.

[0011] To achieve better curing rate and dissolution effect, the volume ratio of ACN to MA / EtOH in the mixed solvent is preferably 1 to 2.5:3, more preferably 2:3, and the mass concentration of MA (methylamine) in MA / EtOH is preferably 20% to 40%, more preferably 30%.

[0012] In the mixed solvent, NH4SCN and MACl are preferably added in an equimolar ratio.

[0013] Preferably, in the mixed solvent, the molar concentrations of NH4SCN and MACl are each independently 1% to 20% of the molar concentration of PbI2. This concentration range exhibits good film quality.

[0014] Further preferably, in the mixed solvent, the molar concentrations of NH4SCN and MACl are both 10% of the molar concentration of PbI2. At this concentration, larger grains and higher crystallinity can be observed.

[0015] Preferably, the annealing temperature is 60–100°C and the time is 5–15 min.

[0016] In a preferred embodiment, the substrate is transparent glass; the cathode is ITO (indium tin oxide); the cathode modification layer is SnO2 (tin dioxide); the anode modification layer is a mixture of Spiro-OMeTAD (2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'spirobifluorene), LiTFSI (Bis(trifluoromethane)sulfonimide lithium salt), and 4-tert-butylpyridine (TBP); and the anode is Ag.

[0017] The present invention also provides a high-efficiency quasi-two-dimensional perovskite solar cell prepared by the method.

[0018] Compared with the prior art, the innovation of this invention lies in the first application of a highly volatile solvent system to a quasi-two-dimensional perovskite system that is highly dependent on orientation to achieve good device performance, and the realization of (GA)2(MA) by means of specific solid additives. n-1 Pb n I 3n+1 The slow growth of crystals brings the following advantages:

[0019] 1. This strategy utilizes a highly volatile methylamine / acetonitrile solvent system to promote (GA)2(MA) n-1 Pb n I 3n+1 Quasi-two-dimensional perovskite films solidify rapidly within 2–3 seconds, enabling a rapid nucleation process and inducing a large number of nuclei. This ultimately yields dense, smooth, and pinhole-free perovskite films, which greatly contributes to improving the manufacturing efficiency for the future commercialization of perovskites.

[0020] 2. The introduction of high-boiling-point solid additives NH4SCN and CH3NH3Cl achieves a slow but effective (GA)2(MA) synthesis. n-1 Pb n I 3n+1 The crystal growth step further increases the size of the perovskite crystal grains; on the other hand, the introduction of high-boiling-point solid additives NH4SCN and CH3NH3Cl also promotes the perovskite toward (111) and (202) preferred orientations by delaying crystallization, which is particularly important for quasi-two-dimensional perovskites.

[0021] 3. In large-scale device manufacturing, perovskite nucleation and film formation require higher standards. However, with antisolvent deposition, the crystallization process and uniformity of the film are jointly controlled by the curing and antisolvent drop-off processes. The resulting perovskite films often have low crystallinity, high defect density, and numerous small grains with many grain boundaries, severely affecting device performance. Unlike antisolvent deposition, the fast-drying, slow-growth deposition method of this invention controls film uniformity solely through the curing process, avoiding the drop-off of antisolvent. A dense, pinhole-free film can be obtained with simple spin coating, easily coating larger substrate areas without affecting film quality, thus being more conducive to the fabrication of large-area devices.

[0022] Due to the aforementioned advantages, the quasi-two-dimensional perovskite solar cell prepared by this invention achieves a power conversion efficiency of 20.44%, which is higher than that of quasi-two-dimensional perovskite solar cells prepared by the corresponding anti-solvent deposition method (17.60%). This is also one of the highest efficiencies of quasi-two-dimensional perovskite solar cells to date. Furthermore, the fast-drying, slow-growth deposition method shows great promise for large-area perovskite applications; a 1cm [cell diameter] perovskite solar cell prepared based on this method... 2 Quasi-two-dimensional perovskite solar cells achieved a champion efficiency of 19.08%, the highest currently achieved for a 1cm² solar cell. 2 The highest efficiency of large-area quasi-two-dimensional perovskite solar cells. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the preparation of the active layer of a quasi-two-dimensional perovskite solar cell using the antisolvent deposition method and the fast-drying slow-growth deposition method in a specific embodiment of the present invention.

[0024] Figure 2 The test area is 0.05979 cm². 2 The current-voltage curves of high-efficiency quasi-two-dimensional perovskite solar cells prepared by antisolvent deposition and fast-drying slow-growth deposition methods under illumination are presented. The precursor solvent for the active layer prepared by antisolvent deposition was a 4:1 volume ratio DMF (N,N-dimethylformamide):DMSO (dimethyl sulfoxide) mixed solution, which also contained 0.1M MACl / NH4SCN mixed solid additives. During spin coating, 500 μL of ethyl acetate antisolvent was added to the substrate, and the active layer underwent 10 min of annealing at 150℃ and 10 min of annealing at 100℃. The precursor solvent for the active layer prepared by fast-drying slow-growth deposition method was a 2:3 volume ratio ACN:MA (ETOH) mixed solution, which also contained 0.06M MACl / NH4SCN mixed solid additives, and underwent 5 min of annealing at 80℃.

[0025] Figure 3 The test area is 1cm 2Current-voltage curves of quasi-two-dimensional perovskite solar cells prepared by antisolvent deposition and fast-drying slow-growth deposition methods under illumination are presented. The precursor solvent for the active layer prepared by antisolvent deposition was a DMF:DMSO mixed solution with a volume ratio of 4:1, which also contained a 0.1M MACl / NH4SCN mixed solid additive. During spin coating, 500 μL of ethyl acetate antisolvent was added to the substrate, and the active layer underwent 10 min of annealing at 150℃ and 10 min of annealing at 100℃. The precursor solvent for the active layer prepared by fast-drying slow-growth deposition method was an ACN:MA(ETOH) mixed solution with a volume ratio of 2:3, which also contained a 0.06M MACl / NH4SCN mixed solid additive, and underwent 5 min of annealing at 80℃.

[0026] Figure 4 Figures show the GIWAXS test results for quasi-two-dimensional perovskite films prepared by antisolvent deposition and fast-drying slow-growth deposition methods. For the antisolvent deposition method, the precursor solvent for the active layer was a DMF:DMSO mixture (4:1 volume ratio). During spin coating, 500 μL of ethyl acetate antisolvent was added to the substrate, and the active layer underwent consecutive annealing treatments at 150°C for 10 min and at 100°C for 10 min. For the fast-drying slow-growth deposition method, the precursor solvent for the active layer was an ACN:MA(ETOH) mixture (2:3 volume ratio), and it underwent annealing treatment at 80°C for 5 min.

[0027] Figure 5 Figures show the GIWAXS test results for quasi-two-dimensional perovskite films prepared by antisolvent deposition and fast-drying slow-growth deposition methods. The precursor solvent for the active layer prepared by antisolvent deposition was a DMF:DMSO mixed solution with a volume ratio of 4:1, which also contained a 0.1M MACl / NH4SCN mixed solid additive. During spin coating, 500 μL of ethyl acetate antisolvent was added to the substrate, and the active layer underwent consecutive annealing treatments at 150°C for 10 min and at 100°C for 10 min. The precursor solvent for the active layer prepared by fast-drying slow-growth deposition method was an ACN:MA(ETOH) mixed solution with a volume ratio of 2:3, which also contained a 0.06M MACl / NH4SCN mixed solid additive, and underwent annealing treatment at 80°C for 5 min.

[0028] Figure 6 This image shows the SEM (scanning electron microscope) morphology of a highly efficient quasi-two-dimensional perovskite thin film prepared by a fast-drying, slow-growth deposition method. The precursor solvent for the active layer was a 2:3 volume ratio ACN:MA(ETOH) mixed solution, which was annealed at 80°C for 5 minutes.

[0029] Figure 7SEM images show the morphology of a high-efficiency quasi-two-dimensional perovskite film prepared by a fast-drying, slow-growth deposition method. The precursor solvent for the active layer is a 2:3 volume ratio ACN:MA(ETOH) mixed solution, which also contains a 0.06 M concentration of MACl / NH4SCN mixed solid additive, and is annealed at 80 °C for 5 min. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions reported in the literature or under conditions recommended by the manufacturer.

[0031] Comparative Example 1

[0032] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes each, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The sheet was then transferred to a dry air glove box. (See antisolvent deposition method). Figure 1 ): Add (GA)2(MA) at a concentration of 1M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor (n=5) was prepared in a 4:1 DMF:DMSO mixture. Before spin coating, 0.1 M NH4SCN and 0.1 M CH3NH3Cl (MACl) were added. The mixture was spin-coated at 4000 rpm for 25 s, with 500 μL of ethyl acetate as a countersolvent added dropwise to the substrate at the 9th second to obtain the active layer. The active layer was then subjected to consecutive annealing treatments at 150 °C for 10 min and 100 °C for 10 min. Then, a Spiro-OMeTAD modification layer was spin-coated onto the active layer using a Spiro-OMeTAD chlorobenzene solution composed of 72.3 mg Spiro OMeTAD, 17.5 μL of lithium bis(trifluoromethane)sulfonylimide salt solution (520 mg LiTFSI in 1 ml acetonitrile), 28.8 μL of 4-tert-butylpyridine, and 1 ml of chlorobenzene. Finally, a 100 nm thick Ag electrode (anode) was deposited using a vapor deposition apparatus, resulting in a test area of ​​0.05979 cm². 2 Quasi-two-dimensional perovskite solar cells.

[0033] At a light intensity of 100mW / cm 2Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, and the PCE (power conversion efficiency) was found to be 17.60%.

[0034] Figure 2 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0035] Comparative Example 2

[0036] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes each, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The sheet was then transferred to a dry air glove box. (See antisolvent deposition method). Figure 1 ): Add (GA)2(MA) at a concentration of 1M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor (n=5) was prepared in a 4:1 DMF:DMSO mixture. Before spin coating, 0.1 M NH4SCN and 0.1 M CH3NH3Cl (MACl) were added. The mixture was spin-coated at 4000 rpm for 25 s, with 500 μL of ethyl acetate as a countersolvent added dropwise to the substrate at the 9th second to obtain the active layer. The active layer was then subjected to consecutive annealing treatments at 150 °C for 10 min and 100 °C for 10 min. Then, a Spiro-OMeTAD modification layer was spin-coated onto the active layer using a Spiro-OMeTAD chlorobenzene solution composed of 72.3 mg Spiro OMeTAD, 17.5 μL of bis(trifluoromethane)sulfonylimide lithium salt solution (520 mg LiTFSI in 1 ml acetonitrile), 28.8 μL of 4-tert-butylpyridine, and 1 ml of chlorobenzene. Finally, a 100 nm thick Ag electrode (anode) was deposited using a vapor deposition apparatus, resulting in a test area of ​​1 cm². 2 Quasi-two-dimensional perovskite solar cells.

[0037] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, and the PCE was found to be 15.08%. (Comparison) Figure 2 , Figure 3 In the anti-solvent deposition method, as the size of the fabricated quasi-two-dimensional perovskite solar cells increases, the PCE decreases significantly faster than in the fast-drying slow-growth deposition method of this invention.

[0038] Figure 3 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0039] Example 1

[0040] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The wafer was then transferred to a dry air glove box. (See fast-drying slow-growth deposition method). Figure 1 ): Add (GA)2(MA) at a concentration of 0.6M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor with n=5 was prepared by spin-coating a mixed solution of ACN:MA / EtOH (MA concentration of 30% by volume) at a ratio of 2:3. Before spin-coating, 0.06 M NH4SCN and 0.06 M CH3NH3Cl (MACl) were added. The solution was spin-coated at 4000 rpm for 60 s to obtain the active layer. The active layer was then annealed at 80 °C for 5 min. Then, a Spiro-OMeTAD modification layer was spin-coated onto the active layer using a Spiro-OMeTAD chlorobenzene solution composed of 72.3 mg Spiro OMeTAD, 17.5 μL of bis(trifluoromethane)sulfonylimide lithium salt solution (520 mg LiTFSI in 1 ml acetonitrile), 28.8 μL of 4-tert-butylpyridine, and 1 ml of chlorobenzene. Finally, a 100 nm thick Ag electrode (anode) was deposited using a vapor deposition apparatus, resulting in a test area of ​​0.05979 cm². 2 Quasi-two-dimensional perovskite solar cells.

[0041] At a light intensity of 100mW / cm 2 Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the device was tested, and the PCE was found to be 20.44%.

[0042] Figure 2 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0043] Example 2

[0044] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The wafer was then transferred to a dry air glove box. (See fast-drying slow-growth deposition method). Figure 1 ): Add (GA)2(MA) at a concentration of 0.6M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor with n=5 was spin-coated in a 2:3 volume ratio (ACN:MA / EtOH, where MA in MA / EtOH is 30% by mass) solution. Before spin-coating, 0.06 M NH4SCN and 0.06 M CH3NH3Cl (MACl) were added. The solution was spin-coated at 4000 rpm for 60 s to obtain the active layer. The active layer was then annealed at 80 °C for 5 min. A Spiro-OMeTAD modification layer was then spin-coated onto the active layer using a Spiro-OMeTAD chlorobenzene solution composed of 72.3 mg Spiro OMeTAD, 17.5 μL of bis(trifluoromethane)sulfonylimide lithium salt solution (520 mg LiTFSI in 1 ml acetonitrile), 28.8 μL of 4-tert-butylpyridine, and 1 ml of chlorobenzene. Finally, a 100 nm thick Ag electrode (anode) was deposited using a vapor deposition apparatus to obtain a test area of ​​1 cm². 2 Quasi-two-dimensional perovskite solar cells.

[0045] At a light intensity of 100mW / cm 2 The current-voltage curve of the device was tested under AM1.5 simulated sunlight, and the PCE was found to be 19.08%.

[0046] Figure 3 The device is given under illumination of 100 mW / cm². 2 The AM1.5 simulated current-voltage curve under sunlight.

[0047] Comparative Example 3

[0048] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes each, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The sheet was then transferred to a dry air glove box. (See antisolvent deposition method). Figure 1): Add (GA)2(MA) at a concentration of 1M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor (n=5) was spin-coated for 25 s at 4000 rpm in a DMF:DMSO mixture (4:1 volume ratio). At the 9th second, 500 μL of ethyl acetate was added dropwise to the substrate as an anti-solvent to obtain the active layer. The active layer was then subjected to consecutive annealing treatments at 150 °C for 10 min and 100 °C for 10 min to obtain a quasi-two-dimensional perovskite solar cell active layer film obtained by anti-solvent deposition.

[0049] The film was subjected to GIWAXS testing using a Xeuss 2.0 SAXS / WAXS laboratory beamline, which revealed that the perovskite film prepared by antisolvent deposition exhibited strong diffraction rings, indicating random orientation.

[0050] Figure 4 The test results for the GIWAXS thin film are presented.

[0051] Comparative Example 4

[0052] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes each, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The sheet was then transferred to a dry air glove box. (See antisolvent deposition method). Figure 1 ): Add (GA)2(MA) at a concentration of 1M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor (n=5) was prepared in a DMF:DMSO mixture (4:1 volume ratio). Before spin-coating, 0.1 M NH4SCN and 0.1 M CH3NH3Cl (MACl) were added. The mixture was spin-coated at 4000 rpm for 25 s, with 500 μL of ethyl acetate as an antisolvent added dropwise to the substrate at the 9th second to obtain the active layer. The active layer was then annealed consecutively at 150 °C for 10 min and 100 °C for 10 min to obtain a quasi-two-dimensional perovskite solar cell active layer film obtained by antisolvent deposition.

[0053] The film was subjected to GIWAXS testing using a Xeuss 2.0 SAXS / WAXS laboratory beamline, and similar experimental results were obtained as in Comparative Example 3. This indicates that the introduction of MACl / NH4SCN into the DMF:DMSO mixed solvent of the antisolvent deposition method has no effect on the crystallinity and crystal orientation of the film.

[0054] Figure 5 The test results for the GIWAXS thin film are presented.

[0055] Comparative Example 5

[0056] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The wafer was then transferred to a dry air glove box. (See fast-drying slow-growth deposition method). Figure 1 ): Add (GA)2(MA) at a concentration of 0.6M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor (n=5) was spin-coated for 60 s at 4000 rpm in a 2:3 volume ratio of ACN:MA / EtOH (MA mass concentration in MA / EtOH was 30%) to obtain an active layer. The active layer was then annealed at 80 °C for 5 min to obtain a quasi-two-dimensional perovskite solar cell active layer film obtained by a fast-drying, slow-growth deposition method.

[0057] The thin film was subjected to GIWAXS testing using a Xeuss 2.0 SAXS / WAXS laboratory beamline, yielding some discrete Bragg spots and patterns at q = 0.3 and... Nearby, diffraction rings associated with 1D GAPbI3 confirmed the randomness of the orientation in Comparative Example 5.

[0058] Figure 4 The test results for the GIWAXS thin film are presented.

[0059] Example 3

[0060] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The wafer was then transferred to a dry air glove box. (See fast-drying slow-growth deposition method). Figure 1): Add (GA)2(MA) at a concentration of 0.6M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor (n=5) was prepared by spin-coating a mixed solution of ACN:MA / EtOH (MA concentration of 30%) in a volume ratio of 2:3. Before spin-coating, 0.06 M NH4SCN and 0.06 M CH3NH3Cl (MACl) were added. The solution was spin-coated at 4000 rpm for 60 s to obtain the active layer. The active layer was then annealed at 80 °C for 5 min to obtain a quasi-two-dimensional perovskite solar cell active layer film obtained by a fast-drying, slow-growth deposition method.

[0061] The film was subjected to GIWAXS testing using a Xeuss 2.0 SAXS / WAXS laboratory beamline. Compared to Comparative Example 5, an increase was observed along q... z Direction represents peak and along q xy The discrete Bragg spots representing the (111) and (202) peaks confirm that the introduction of MACl / NH4SCN into the fast-drying solvent system of the fast-drying slow-growth deposition method of the present invention facilitates perovskite growth perpendicular to the substrate; furthermore, compared with Comparative Example 5, at q = 0.3 and Nearby, the diffraction rings associated with 1D GAPbI3 disappeared significantly, further confirming that the introduction of MACl / NH4SCN into the fast-drying solvent system of the fast-drying slow-growth deposition method of this invention contributes to the preferred orientation during the perovskite growth process.

[0062] Figure 5 The test results for the GIWAXS thin film are presented.

[0063] Comparative Example 6

[0064] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The wafer was then transferred to a dry air glove box. (See fast-drying slow-growth deposition method). Figure 1 ): Add (GA)2(MA) at a concentration of 0.6M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1A quasi-two-dimensional perovskite precursor (n=5) was spin-coated for 60 s at 4000 rpm in a 2:3 volume ratio of ACN:MA / EtOH (MA mass concentration in MA / EtOH was 30%) to obtain an active layer. The active layer was then annealed at 80 °C for 5 min to obtain a quasi-two-dimensional perovskite solar cell active layer film obtained by a fast-drying, slow-growth deposition method.

[0065] The morphology of the film was characterized using field emission scanning electron microscopy, revealing a smooth and flat perovskite film with small grain size. This confirmed that highly volatile solvents are beneficial for improving the coverage and uniformity of the film, but are lacking in delaying crystal growth.

[0066] Figure 6 The test results of the film morphology are presented.

[0067] Example 4

[0068] Transparent conductive glass coated with ITO (cathode) was sequentially ultrasonically cleaned with cleaning agent, deionized water, acetone, isopropanol, and anhydrous ethanol for 15 minutes, dried, and then treated with ultraviolet ozone for 20 minutes. A layer of SnO2 was then spin-coated onto the conductive glass surface at 3000 rpm, followed by annealing at 150°C for 30 minutes. The wafer was then transferred to a dry air glove box. (See fast-drying slow-growth deposition method). Figure 1 ): Add (GA)2(MA) at a concentration of 0.6M (based on PbI2, with GAI and MAI added in stoichiometric ratio). n-1 Pb n I 3n+1 A quasi-two-dimensional perovskite precursor (n=5) was prepared by spin-coating a mixed solution of ACN:MA / EtOH (MA concentration of 30%) in a volume ratio of 2:3. Before spin-coating, 0.06 M NH4SCN and 0.06 M CH3NH3Cl (MACl) were added. The solution was spin-coated at 4000 rpm for 60 s to obtain the active layer. The active layer was then annealed at 80 °C for 5 min to obtain a quasi-two-dimensional perovskite solar cell active layer film obtained by a fast-drying, slow-growth deposition method.

[0069] The morphology of the film was characterized using field emission scanning electron microscopy, revealing a perovskite film without pinholes, with fewer grain boundaries, larger grains, and good vertical penetration. This confirms that the introduction of MACl / NH4SCN into the fast-drying solvent system of the fast-drying slow-growth deposition method of this invention helps to delay the growth of (GA)2(MA). n-1 Pb n I 3n+1 A faster crystal growth rate is more conducive to building high-performance devices.

[0070] Figure 7 The test results of the film morphology are presented.

[0071] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A method for preparing high-efficiency quasi-two-dimensional perovskite solar cells using a fast-drying, slow-growth deposition method, characterized in that, include: From bottom to top, a substrate, a cathode, a cathode modification layer, an active layer, an anode modification layer, and an anode are sequentially arranged to form the high-efficiency quasi-two-dimensional perovskite solar cell. The active layer is prepared using a fast-drying, slow-growth deposition method, specifically comprising: adding GAI, MAI, and PbI2 in stoichiometric ratios to a mixed solvent of ACN and MA / EtOH, wherein NH4SCN and MACl are also added to the mixed solvent; then spin-coating the mixture onto the cathode modification layer and annealing to obtain (GA)2(MA). n-1 Pb n I 3n+1 Quasi-two-dimensional perovskite thin film active layer, where n≥3; In the mixed solvent, the volume ratio of ACN to MA / EtOH is 1 to 2.5:3, and the mass concentration of MA in MA / EtOH is 20% to 40%. In the mixed solvent, the molar concentrations of NH4SCN and MACl are each independently 1% to 20% of the molar concentration of PbI2; The annealing temperature is 60–100°C, and the time is 5–15 minutes.

2. The method according to claim 1, characterized in that, The concentration of PbI2 in the mixed solvent is 0.5–0.7 M.

3. The method according to claim 1, characterized in that, In the mixed solvent, NH4SCN and MACl are added in an equimolar ratio.

4. The method according to claim 1, characterized in that, The substrate is transparent glass; the cathode is ITO; the cathode modification layer is SnO2; the anode modification layer is a mixture of Spiro-OMeTAD, LiTFSI and 4-tert-butylpyridine; and the anode is Ag.

5. A high-efficiency quasi-two-dimensional perovskite solar cell prepared by the method according to any one of claims 1 to 4.

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