Stable perovskite precursor solution and preparation method and application thereof

Abstract

The invention provides a stable perovskite precursor solution and a preparation method and application thereof. The perovskite precursor solution comprises a solute, a solvent and a stabilizer; the stabilizer comprises a compound containing a reducing group and a hydrogen ion group capable of being ionized; the solute comprises bromomethylamine, formamidine iodide, chloromethylamine, cesium iodide, lead iodide and lead bromide. The preparation method comprises the following steps: mixing a solute and a solvent, adding a stabilizer into the mixture, and mixing to obtain the perovskite precursor solution. According to the invention, the specific composition of the perovskite precursor solution is designed, and a specific stabilizer is further used, so that the perovskite precursor solution with relatively high stability and a relatively good storage effect is prepared.

Description

[0001] This application claims priority to patent application number 2024114677622 (the filing date of the prior application is October 21, 2024, and the name of the invention is a stable perovskite precursor solution, preparation method and application thereof). Technical Field

[0002] The invention belongs to the technical field of perovskite solar cells, and in particular relates to a stable perovskite precursor solution and a preparation method and application thereof. Background Art

[0003] Before preparing perovskite films by solution method, appropriate temperature and stirring conditions are required to ensure the complete dissolution of precursor components. In the future industrial production process, perovskite ink usually needs to be prepared in large quantities and stored for days or even months, which may take a long time. Compared with the research hotspot of improving the efficiency and stability of perovskite solar cells, the stability of its precursor solution has never received enough attention.

[0004] In fact, the rheological properties of the perovskite precursor solution are closely related to the photoelectric performance of solar cells. It is essentially a uniformly dispersed colloidal solution rather than a pure solution. A slight change in the stoichiometric ratio of organic and inorganic components will have a significant effect on the size and morphological properties of the colloidal particles, thereby affecting the crystallization properties of the final perovskite film. Therefore, the composition of the precursor solution must remain highly stable under complex working conditions. This will help solve the technical difficulties of large-area component stability, preparation reproducibility, and insufficient product yield of perovskite solar cells.

[0005] For the methylamine lead iodide (MAPbI3) single perovskite system, as long as the solution system is sufficiently sealed, the material itself is still very stable. However, when methylamine and formamidine coexist in the solution system, a series of solution aging reactions will inevitably occur during the storage process due to the reactivity between the mixed components.

[0006] Therefore, in future large-scale production, the need for precise proportioning of precursor solutions will greatly increase the difficulty and complexity of the process. If the short-term effectiveness of the precursor cannot be overcome, the manufacturing cost will be greatly increased. In the existing wet process, the aging process mainly includes two aspects. First, the highly active iodine ions in the precursor solution will be oxidized to form iodine or I3 after contacting trace amounts of oxygen. - Secondly, the deprotonation reaction of organic cations and the subsequent amine-cation side reaction will lead to the degradation of the perovskite precursor solution, thereby deteriorating the photovoltaic performance and production yield of photovoltaic modules.

[0007] At the same time, it is equally important to prevent the degradation of the perovskite precursor solution. Improving its solution stability is to broaden the time window in which the solution is available. In existing studies, by introducing Lewis base molecules containing empty orbitals, additives carrying reducing groups, or directly adjusting the solution pH, the deprotonation of organic cations or the oxidation reaction of iodide ions can be effectively limited, forming a more stable perovskite colloidal solution. However, in mixed cation perovskite precursor solutions, the oxidation of iodide ions, the deprotonation of organic cations, and the subsequent amine-cation reaction often occur simultaneously, and a single-functional additive cannot simultaneously inhibit all side reactions. Therefore, finding a precursor stabilizer that can inhibit all side reactions is crucial for promoting the industrial application of perovskite solar cells at this stage.

[0008] The precursor solution used in the preparation of large-area perovskite films has a short shelf life and is prone to degradation after long-term storage. In addition, the current methods for stabilizing the precursor solution are relatively single and cannot fully solve problems such as solution aging.

[0009] Therefore, how to provide a perovskite precursor solution with higher stability and better storage effect has become a technical problem that needs to be solved urgently. Summary of the invention

[0010] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a stable perovskite precursor solution and a preparation method and application thereof. The present invention designs the specific composition of the perovskite precursor solution and further prepares a perovskite precursor solution with high stability and good storage effect by using a specific stabilizer.

[0011] To achieve this object, the present invention adopts the following technical solutions:

[0012] In a first aspect, the present invention provides a stable perovskite precursor solution, wherein the perovskite precursor solution comprises a solute, a solvent and a stabilizer;

[0013] The stabilizer includes a compound containing a reducing group and a group capable of ionizing hydrogen ions;

[0014] The solutes include methylamine bromide, iodoformamidine, methylamine chloride, cesium iodide, lead iodide and lead bromide.

[0015] In the prior art, the shelf life of perovskite precursor solutions is short and they are prone to degradation after long-term storage. In addition, the current methods for stabilizing precursor solutions are relatively simple and cannot fully solve problems such as solution aging. The present invention designs the specific composition of the perovskite precursor solution and further uses a specific stabilizer to prepare a perovskite precursor solution with high stability and good storage effect. The stabilizer contains a reducing functional group and a group that can ionize hydrogen ions, thereby improving the photovoltaic performance and reproducibility of perovskite solar cells.

[0016] The aging problem of perovskite precursor solution mainly manifests itself in two aspects: first, iodine anions are easily oxidized to iodine in the air; second, methylamine cations (MA + ) after deprotonation, the generated methylamine (MA) reacts with the formamidinium cation (FA + ) to generate N-methylformamidinium cation (MFA + ) and N,N'-dimethylformamidinium cation (DMFA + ), the specific aging mechanism is shown in equations ①-③. By introducing carboxyl (-COOH) and thiol (-SH) groups that can ionize hydrogen ions, as well as hydrazine (-NHNH2) and thiol (-SH) groups with reducing functions, the above two aging problems can be effectively inhibited. The specific inhibition reaction mechanism is shown in equations ④-⑦.

[0017] The present invention prepares a perovskite precursor solution with high stability and good storage effect through the synergistic effect of the group capable of ionizing hydrogen ions and the reducing group in the stabilizer.

[0018]

[0019] The precursor solution provided by the present invention can be subsequently used for the preparation of large-area perovskite, and the photovoltaic performance of the prepared perovskite solar cell is little affected by the storage time of the precursor solution. The provided method can reduce the generation of byproduct iodine in the perovskite precursor solution and inhibit the deprotonation reaction of organic cations, improve the quality of perovskite film crystals, and avoid the waste of unused precursor solution. The perovskite solar cell is prepared with a newly prepared precursor solution and a precursor solution stored for 15 days, and the efficiency change does not exceed 5%.

[0020] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0021] As a preferred technical solution of the present invention, the ratio of the mass of the solute to the volume of the solvent is (0.8-1.2) g:1 mL, for example, it can be 0.8 g:1 mL, 0.85 g:1 mL, 0.9 g:1 mL, 0.95 g:1 mL, 1 g:1 mL, 1.05 g:1 mL, 1.1 g:1 mL, 1.15 g:1 mL or 1.2 g:1 mL, etc.

[0022] Taking the mass percentage of the solute as 100%, the mass percentage of the stabilizer is 0.3-1.5%, for example, it can be 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4% or 1.5%, etc.

[0023] The present invention can further improve the stability and storage effect of the perovskite precursor solution by controlling the amount of the stabilizer within a specific range. If the amount of the stabilizer is too little, the stability and storage effect of the perovskite precursor solution are poor; if the amount of the stabilizer is too much, the excess stabilizer will interfere with the perovskite nucleation and crystallization process, resulting in a decrease in the quality of the perovskite crystal, and ultimately affecting the photoelectric conversion efficiency and stability of the prepared device.

[0024] As a preferred technical solution of the present invention, the group capable of ionizing hydrogen ions includes any one of a carboxyl group (-COOH), a sulfonic acid group (-SO3H) or a phenol group (-C6H5OH) or a combination of at least two of them.

[0025] Preferably, the reducing group includes any one or a combination of at least two of a hydrazine group (—NH—NH 2 ), a thiol group (—SH), an amino group (—NH 2 ) or a hydroxyl group (—OH).

[0026] As a preferred technical solution of the present invention, the stabilizer is selected from any one of thioglycolic acid, dimercaptoacetic acid, mercaptopropionic acid, mercaptobutyric acid, mercaptobenzoic acid, mercaptophenylacetic acid, mercaptosuccinic acid, mercaptoglutaric acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 2-aminobenzoic acid hydrochloride, p-methylaminophenylhydrazine hydrochloride, 2-hydrazinebenzoic acid, 3-hydrazinebenzoic acid, and 4-hydrazinebenzoic acid.

[0027] As a preferred technical solution of the present invention, taking the sum of the mass percentages of the solutes as 100%, the solutes include the following components in mass percentage: 0.1-2% of methyl bromide, 10-30% of iodomethane, 0.5-5% of methyl chloride, 50-80% of lead iodide, 1-5% of lead bromide and the remainder of cesium iodide.

[0028] In the present invention, the mass percentage of methyl bromide in the solute can be 0.1%, 0.2%, 0.4%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8% or 2%, etc.

[0029] The mass percentage of iodoformamidine in the solute can be 10%, 12%, 15%, 18%, 20%, 23%, 25%, 27% or 30%, etc.

[0030] The mass percentage of chloromethylamine in the solute can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, etc.

[0031] The mass percentage of lead iodide in the solute can be 50%, 52%, 54%, 56%, 58%, 60%, 63%, 66%, 68%, 70%, 72%, 75%, 77%, 78% or 80%, etc.

[0032] The mass percentage of lead bromide in the solute can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, etc.

[0033] As a preferred technical solution of the present invention, the solvent includes any one of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone, or a combination of at least two thereof.

[0034] Preferably, the solvent comprises a combination of N,N-dimethylformamide and dimethyl sulfoxide, or the solvent comprises a combination of N,N-dimethylformamide and N-methylpyrrolidone.

[0035] Preferably, the solvent comprises a combination of N,N-dimethylformamide and dimethyl sulfoxide. Taking the volume percentage of the solvent as 100%, the solvent comprises the following components in volume percentage: 70-90% of N,N-dimethylformamide (for example, 70%, 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88% or 90%, etc.) and 10-30% of dimethyl sulfoxide (for example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, etc.).

[0036] Preferably, the solvent comprises a combination of N,N-dimethylformamide and N-methylpyrrolidone. Taking the volume percentage of the solvent as 100%, the solvent comprises the following components in volume percentage: 70-90% of N,N-dimethylformamide (for example, 70%, 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88% or 90%, etc.) and 10-30% of N-methylpyrrolidone (for example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, etc.).

[0037] In a second aspect, the present invention provides a method for preparing a stable perovskite precursor solution as described in the first aspect, the preparation method comprising the following steps:

[0038] After the solute and the solvent are mixed, a stabilizer is added thereto and mixed to obtain the perovskite precursor solution.

[0039] As a preferred technical solution of the present invention, the temperature at which the solute and the solvent are mixed is 65-75°C, for example, it can be 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C or 75°C.

[0040] Preferably, the solute and the solvent are mixed for 5 to 15 minutes, for example, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes or 15 minutes.

[0041] Preferably, the mixing temperature after adding the stabilizer is 65-75°C, for example, it can be 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C or 75°C, etc.

[0042] Preferably, the mixing time after adding the stabilizer is 10 to 14 hours, for example, it can be 10 hours, 10.5 hours, 11 hours, 11.5 hours, 12 hours, 12.5 hours, 13 hours, 13.5 hours or 14 hours.

[0043] As a preferred technical solution of the present invention, the preparation method specifically comprises the following steps:

[0044] After mixing the solute and the solvent at 65 to 75° C. for 5 to 15 minutes, a stabilizer is added thereto, and the mixture is mixed at 65 to 75° C. for 10 to 14 hours to obtain the perovskite precursor solution.

[0045] In a third aspect, the present invention provides a use of the stable perovskite precursor solution as described in the first aspect, wherein the perovskite precursor solution is used to prepare a perovskite solar cell.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) The present invention designs the specific composition of the perovskite precursor solution and further uses a stabilizer containing a reducing functional group and a group that can ionize hydrogen ions to prepare a perovskite precursor solution with high stability and good storage effect. The open circuit voltage of the perovskite solar cell prepared from the freshly prepared perovskite precursor solution is 1.13-1.19V, and the current density is 22.35-25.92mA·cm -2 The fill factor is 72.24-80.21%, the photoelectric conversion efficiency is 18.41-23.82%, and the open circuit voltage of the perovskite precursor solution decreases by 0-0.07V and the current density decreases by 0.37-3.96mA·cm after aging for 15 days under 50% relative humidity air storage conditions. -2 The fill factor changed by 0.04-10.52%, and the photoelectric conversion efficiency decreased by 0.85-7.33%. After aging for 120 days under nitrogen atmosphere, the open circuit voltage of the perovskite precursor solution decreased by 0-0.04 V and the current density decreased by 0.16-3.27 mA·cm -2 , the filling factor changed by 0.03 to 8.32%, and the photoelectric conversion efficiency decreased by 0.15 to 5.78%.

[0048] (2) The present invention further improves the comprehensive performance of the perovskite precursor solution by controlling the amount of the stabilizer within a specific range. The open circuit voltage of the perovskite solar cell prepared from the freshly prepared perovskite precursor solution is 1.16-1.19 V, and the current density is 23.18-25.92 mA·cm -2 , the fill factor is 74.64-80.15%, and the photoelectric conversion efficiency is 20.06-23.82%; after aging for 15 days in 50% relative humidity air, the open circuit voltage decreased by 0-0.02V, and the current density decreased by 0.37-2.28mA·cm -2 , the fill factor changed by 0.04-4.48%, and the photoelectric conversion efficiency decreased by 0.85-2.88%. Under nitrogen atmosphere storage conditions, after aging for 120 days, the open circuit voltage of the perovskite precursor solution decreased by 0-0.02V, and the current density decreased by 0.16-2.66mA·cm -2 , the filling factor changed by 0.03 to 4.64%, and the photoelectric conversion efficiency decreased by 0.15 to 4.19%. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1The SEM images of perovskite crystals prepared using the “fresh” or “aged for 15 days” perovskite precursor solutions provided in Example 1;

[0050] Figure 2 SEM images of perovskite crystals prepared using the “fresh” or “aged for 15 days” perovskite precursor solutions provided in Comparative Example 1;

[0051] Figure 3 This is a comparison chart of the ultraviolet absorption intensity of perovskite films prepared using the "fresh" or "aged for 15 days" perovskite precursor solution provided in Example 1;

[0052] Figure 4 A comparison chart of the ultraviolet absorption intensity of perovskite films prepared using the "fresh" or "aged for 15 days" perovskite precursor solutions provided in Comparative Example 1;

[0053] Figure 5 The graphs are respectively showing the change in efficiency of solar cells prepared with the perovskite precursor solutions provided in Example 1 and Comparative Example 1 as a function of the storage time of the precursor solutions (i.e., the aging time of the solutions);

[0054] Here, “fresh” refers to the test using the freshly prepared perovskite precursor solution, and “aged for 15 days” refers to the test after being stored in 50% relative humidity air for 15 days. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0056] Example 1-Example 11, Comparative Examples 1-3

[0057] Example 1 to Example 11 and Comparative Examples 1-3 respectively provide a perovskite precursor solution and a preparation method thereof. The specific composition of the perovskite precursor solution is shown in Table 1-2 below.

[0058] The preparation method of the above perovskite precursor solution is as follows:

[0059] After the solute and the solvent were mixed at 70° C. for 10 minutes, a stabilizer was added thereto, and the temperature was maintained at 70° C. and mixed for 12 hours to obtain the perovskite precursor solution.

[0060] Table 1

[0061]

[0062] Table 2

[0063]

[0064] Perovskite crystals were prepared using the "fresh" or "aged for 15 days" perovskite precursor solutions provided in Example 1 and Comparative Example 1, and the preparation method was as follows: the perovskite precursor solution was prepared in a specific ratio, and after ensuring that it was fully mixed and dissolved, an appropriate amount of stabilizer was added; the perovskite precursor solution was evenly coated on the substrate using a meniscus scraping method; then, the substrate was transferred to a hot stage at 150° C. and annealed for 10 minutes to prepare perovskite crystals.

[0065] The morphology of the above perovskite crystals was characterized using a Japanese JSM-7500F scanning electron microscope. The characterization results are as follows: Figure 1-2 As shown. Figure 1-2 It can be seen that the morphology of the perovskite crystals prepared by using the stabilizer-containing perovskite precursor solution (Example 1) remains basically unchanged, indicating that the component stability of the perovskite precursor solution provided in Example 1 is greatly enhanced and the storage property is good.

[0066] The perovskite film was prepared using the "fresh" or "aged for 15 days" perovskite precursor solution provided in Example 1 and Comparative Example 1, and the preparation method was as follows: the perovskite precursor solution was uniformly coated on the substrate through a meniscus to form a perovskite film (the scraper speed was 5 mm / s, and the distance between the scraper and the substrate was 100 μm).

[0067] The UV absorption results of the above perovskite films were characterized by using a UV-visible spectrometer (Perkin Elmer Lambda 750). The characterization results are as follows: Figure 3-4 As shown. Figure 3-4 It can be seen that: with the aging time, the ultraviolet absorption of the perovskite film prepared from the perovskite precursor solution without using a stabilizer (Comparative Example 1) changes significantly; while the ultraviolet absorption of the perovskite film prepared from the perovskite precursor solution using a stabilizer (Example 1) remains basically unchanged, indicating that after adding the stabilizer, the component stability of the precursor solution is greatly enhanced.

[0068] Perovskite solar cells were prepared using the perovskite precursor solutions provided in Example 1 and Comparative Example 1 with different storage times, and the preparation method was as follows: first, a polyethylene terephthalate (PET) substrate was ultrasonically treated with detergent, acetone, deionized water and isopropanol for 15 minutes, and then dried with a nitrogen flow; then, the pre-cleaned substrate was placed in a UV chamber for UV-ozone treatment for 5 minutes, a silicon wafer was used as a scraper, and UV-ozone treatment was performed for 10 minutes, and then, after being immersed in an octadecyltrichlorosilane / toluene mixed solution for 20 minutes, it was thermally annealed on a hot stage at 120° C. for 20 minutes; then, the substrate was heated to 40° C. by a semi-solidified state, and the reaction mixture was heated to 100° C. by a heat treatment process; then, the substrate was heated to 40° C. by a heat treatment process; and finally, the substrate was heated to 100° C. by a semi-solidified state. The [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (Meo-2PACz) solution was deposited by meniscus printing (the gap between the scraper and the substrate was 50 μm, and the scraper moving speed was 10 mm / s), and then placed on a hot stage at 100°C in air for annealing for 30 minutes; the perovskite precursor solution was uniformly printed on the MeO-2PACz substrate through a meniscus (the scraper speed was 5 mm / s, and the distance between the scraper and the substrate was 100 μm), and then the perovskite film was placed on a hot stage at 150°C for annealing for 10 minutes; then, the electron transport layer (6,6)-phenyl-C 61 -Methyl butyrate (PC 61 The BM solution was spun at 6000 rpm for 30 seconds and annealed at 90°C for 30 minutes, and then the barrier layer bathocuproin (BCP) was spin-coated at 6000 rpm for 60 seconds; finally, - 4 Under vacuum conditions of 1.5 Pa, metallic silver with a thickness of 100 nm was deposited by thermal evaporation as the top electrode.

[0069] The efficiency of the above perovskite solar cells was characterized using a solar cell device performance test system (Keithley 2400 source meter and SS-F5-3A solar simulator). The characterization results are shown in Figure 5 As shown. Figure 5 It can be seen that the device efficiency of the perovskite precursor solution without adding stabilizer (Comparative Example 1) dropped to less than 30% of the initial efficiency after storage for 15 days, while the device efficiency of the perovskite precursor solution with added stabilizer (Example 1) dropped by less than 5% after storage for 15 days, indicating that after adding stabilizer, the storage stability of the perovskite precursor solution is greatly enhanced.

[0070] The perovskite solar cells prepared using the perovskite precursor solutions provided in the above embodiments and comparative examples with different storage times and storage conditions are prepared by the same method as above.

[0071] The performance (open circuit voltage (Voc / V), current density (Jsc / mA·cm) of the perovskite solar cells prepared from the perovskite precursor solutions provided in the above examples and comparative examples were analyzed.-2 ), fill factor (FF / %), conversion efficiency (PCE%)), the specific test method is as follows:

[0072] The current density-voltage curves were characterized using a Keithley 2400 source meter. The current was measured under a solar simulator (SS-F5-3A, 100 mW cm -2 , AM 1.5G) with reference silicon solar cells calibrated by NREL. All measurements were performed in a nitrogen environment at room temperature; the reverse scan range was 1.2 V to -0.2 V, the forward scan range was -0.2 V to 1.2 V, each step was 20 mV, and the scan rate was 0.2 V s -1 , the delay time is 30ms.

[0073] The above performance characterization results are shown in Table 3-4 below:

[0074] Table 3 Storage conditions: 50% relative humidity air

[0075]

[0076] Table 4 Storage conditions are nitrogen atmosphere

[0077]

[0078]

[0079] From the above content, it can be seen that the present invention designs the specific composition of the perovskite precursor solution and further uses a stabilizer containing a reducing functional group and a group that can ionize hydrogen ions to prepare a perovskite precursor solution with high stability and good storage effect; the perovskite solar cell prepared from the freshly prepared perovskite precursor solution has an open circuit voltage of 1.13-1.19 V and a current density of 22.35-25.92 mA·cm -2 , the filling factor is 72.24~80.21%, and the photoelectric conversion efficiency is 18.41~23.82%.

[0080] Under 50% relative humidity air storage conditions, after aging for 15 days, the perovskite precursor solution prepared has an open circuit voltage of 1.10-1.17 V and a current density of 19.56-25.09 mA·cm -2 , the fill factor is 66.37-79.40%, and the photoelectric conversion efficiency is 14.67-22.82%. Compared with the perovskite solar cells prepared using fresh perovskite precursor solution, the open circuit voltage is reduced by 0-0.07 V, and the current density is reduced by 0.37-3.96 mA·cm -2, the filling factor changed by 0.04 to 10.52%, and the photoelectric conversion efficiency decreased by 0.85 to 7.33%.

[0081] Under nitrogen atmosphere storage conditions, the perovskite solar cell prepared from the perovskite precursor solution after aging for 120 days has an open circuit voltage of 1.13-1.18 V and a current density of 20.31-25.23 mA·cm -2 , the fill factor is 68.45-80.15%, and the photoelectric conversion efficiency is 15.85-23.67%. Compared with the perovskite solar cells prepared using fresh perovskite precursor solution, the open circuit voltage is reduced by 0-0.04 V, and the current density is reduced by 0.16-3.27 mA·cm -2 , the filling factor changed by 0.03 to 8.32%, and the photoelectric conversion efficiency decreased by 0.15 to 5.78%.

[0082] At the same time, by comparing Examples 1-9 with Examples 10-11, it can be seen that the present invention further improves the comprehensive performance of the perovskite precursor solution by controlling the amount of the stabilizer within a specific range. The open circuit voltage of the perovskite solar cell prepared from the freshly prepared perovskite precursor solution is 1.16-1.19V, and the current density is 23.18-25.92mA·cm -2 , the fill factor is 74.64-80.15%, the photoelectric conversion efficiency is 20.06-23.82%; after aging for 15 days in 50% relative humidity air, the open circuit voltage is 1.15-1.17V, and the current density is 21.74-25.09mA·cm -2 The fill factor is 70.16-79.40%, the photoelectric conversion efficiency is 17.54-22.82%, and the open circuit voltage is reduced by 0-0.02 V and the current density is reduced by 0.37-2.28 mA·cm compared with the perovskite solar cells prepared using fresh perovskite precursor solution. -2 The fill factor changed by 0.04-4.48%, and the photoelectric conversion efficiency decreased by 0.85-2.88%. Under nitrogen atmosphere storage conditions, the open circuit voltage of the perovskite solar cell prepared from the perovskite precursor solution after aging for 120 days was 1.15-1.18 V, and the current density was 21.95-25.23 mA·cm -2 , the fill factor is 71.97-80.15%, and the photoelectric conversion efficiency is 18.17-23.67%. Compared with the perovskite solar cells prepared using fresh perovskite precursor solution, the open circuit voltage is reduced by 0-0.02 V, and the current density is reduced by 0.16-2.66 mA·cm -2 , the filling factor changed by 0.03 to 4.64%, and the photoelectric conversion efficiency decreased by 0.15 to 4.19%.

[0083] From the comparison between Example 3 and Comparative Example 1, it can be seen that the present invention prepares a perovskite precursor solution with higher stability and better storage effect by using a stabilizer.

[0084] From the comparison between Example 3 and Comparative Examples 2-3, it can be seen that the present invention further improves the shelf life of the perovskite precursor solution by designing the structure of the stabilizer and further using a stabilizer containing a reducing functional group and a group that can ionize hydrogen ions.

[0085] In summary, the present invention designs the specific composition of the perovskite precursor solution and further uses a stabilizer containing a reducing functional group and a group that can ionize hydrogen ions, thereby preparing a perovskite precursor solution with high stability and good storage effect, and further preparing a perovskite solar cell with excellent performance.

[0086] The applicant declares that the present invention illustrates the detailed process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A stable perovskite precursor solution, characterized in that: The perovskite precursor solution includes a solute, a solvent and a stabilizer; The stabilizer includes a compound containing a reducing group and a group capable of ionizing hydrogen ions; The solutes include methylamine bromide, iodoformamidine, methylamine chloride, cesium iodide, lead iodide and lead bromide.

2. The perovskite precursor solution according to claim 1, characterized in that The ratio of the mass of the solute to the volume of the solvent is (0.8-1.2) g:1 mL; Taking the mass percentage of the solute as 100%, the mass percentage of the stabilizer is 0.3-1.5%.

3. The perovskite precursor solution according to claim 1 or 2, characterized in that: The group capable of ionizing hydrogen ions includes any one of a carboxyl group, a sulfonic acid group or a phenol group, or a combination of at least two of them; Preferably, the reducing group includes any one of a hydrazine group, a thiol group, an amino group or a hydroxyl group, or a combination of at least two of them.

4. The perovskite precursor solution according to any one of claims 1 to 3, characterized in that: The stabilizer is selected from any one of thioglycolic acid, dimercaptoacetic acid, mercaptopropionic acid, mercaptobutyric acid, mercaptobenzoic acid, mercaptophenylacetic acid, mercaptosuccinic acid, mercaptoglutaric acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 2-aminobenzoic acid hydrochloride, p-methylaminophenylhydrazine hydrochloride, 2-hydrazinebenzoic acid, 3-hydrazinebenzoic acid, and 4-hydrazinebenzoic acid.

5. The perovskite precursor solution according to any one of claims 1 to 4, characterized in that: Taking the sum of the mass percentages of the solute as 100%, the solute includes the following components in mass percentage: 0.1-2% of methyl bromide, 10-30% of iodomethane, 0.5-5% of methyl chloride, 50-80% of lead iodide, 1-5% of lead bromide and the balance of cesium iodide.

6. The perovskite precursor solution according to any one of claims 1 to 5, characterized in that: The solvent includes any one of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone, or a combination of at least two thereof; Preferably, the solvent comprises a combination of N,N-dimethylformamide and dimethyl sulfoxide, or the solvent comprises a combination of N,N-dimethylformamide and N-methylpyrrolidone; Preferably, the solvent comprises a combination of N,N-dimethylformamide and dimethyl sulfoxide, and based on the volume percentage of the solvent being 100%, the solvent comprises the following components in volume percentages: 70-90% of N,N-dimethylformamide and 10-30% of dimethyl sulfoxide; Preferably, the solvent comprises a combination of N,N-dimethylformamide and N-methylpyrrolidone. Taking the volume percentage of the solvent as 100%, the solvent comprises the following components in volume percentage: 70-90% of N,N-dimethylformamide and 10-30% of N-methylpyrrolidone.

7. A method for preparing a stable perovskite precursor solution according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: After the solute and the solvent are mixed, a stabilizer is added thereto and mixed to obtain the perovskite precursor solution.

8. The preparation method according to claim 7, characterized in that: The temperature at which the solute and the solvent are mixed is 65 to 75°C; Preferably, the solute and solvent are mixed for 5 to 15 minutes; Preferably, the mixing temperature after adding the stabilizer is 65 to 75°C; Preferably, the mixing time after adding the stabilizer is 10 to 14 hours.

9. The preparation method according to claim 7 or 8, characterized in that: The preparation method specifically comprises the following steps: After mixing the solute and the solvent at 65 to 75° C. for 5 to 15 minutes, a stabilizer is added thereto and mixed at 65 to 75° C. for 10 to 14 hours to obtain the perovskite precursor solution.

10. A use of the stable perovskite precursor solution according to any one of claims 1 to 6, characterized in that: The perovskite precursor solution is used to prepare a perovskite solar cell.

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