Large-area perovskite thin film and preparation method and application thereof

Abstract

The invention provides a large-area perovskite thin film, which is based on GBL / GVL and GVL / NMP green solvents, and solves the problems of difficulty in large-area thin film preparation, environment unfriendliness and high cost caused by a traditional solvent. A new way is provided for large-scale and high-efficiency preparation of the perovskite thin film, and the method has extremely important significance and wide application prospects in the field of renewable energy sources.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a large-area perovskite film and a preparation method and application thereof. Background Art

[0002] Perovskite solar cell modules (PSM) are strong competitors for the next generation of photovoltaic technology due to their high efficiency, good solution processability and low cost. At present, for the commercialization of perovskite photovoltaic technology, the environmental friendliness and sustainability of the perovskite thin film preparation method and the sufficient time window for controlling crystallization in the preparation of perovskite thin films are crucial. In addition to the safety issue of lead toxicity, the use of organic solvents is another pain point in the preparation process of PSM. The scalable solution preparation of perovskite thin films is plagued by the problem of solvent volatility. If harmful solvents are used, it will cause more environmental problems. Traditional perovskite thin film preparation technology often uses toxic solvents such as N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and chlorobenzene. During the preparation process, the perovskite precursor is generally dissolved in these organic solvents and a thin film is formed on the substrate by spin coating, doctor blade coating, etc. The use of traditional solvents has the following disadvantages:

[0003] 1. Environmentally unfriendly: Organic solvents such as DMF and DMSO are highly toxic and pose potential hazards to the environment and the health of operators. These solvents generate hazardous gases and liquid waste during production, use, and disposal, which is inconsistent with the concept of green chemistry.

[0004] 2. High cost: Traditional organic solvents are relatively expensive and difficult to recycle. Solvent costs account for a significant portion of the cost of large-scale perovskite film production. The extensive use of these solvents also results in high post-processing costs, including waste disposal and solvent recovery.

[0005] To overcome these challenges and promote the sustainable development and large-scale commercial application of perovskite photovoltaic technology, the preparation of large-area perovskite thin films based on green solvents has become a research hotspot. Perovskite films prepared using green solvents have been applied not only to traditional single-junction rigid solar cells but also to a variety of novel device structures, such as flexible solar cells and perovskite-silicon tandem solar cells. These achievements have further promoted the commercialization of perovskite photovoltaic technology and broadened the application prospects of green solvent-based perovskite thin film preparation technology in the renewable energy sector.

[0006] However, current perovskite film preparation based on green solvent technology struggles to achieve uniform, dense, and fully phase-transitioned thin films. Due to the complexing and volatility properties of green solvents, they struggle to match the perovskite nucleation and crystallization processes, leading to uneven film formation when preparing large-area films. The resulting film quality is significantly inferior to that achieved using traditional solvents like DMF and DMSO, severely limiting film quality. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention provides large-area perovskite films based on green solvents such as GBL / GVL and GVL / NMP. These solutions address the difficulties, environmental unfriendliness, and high costs associated with traditional solvents in preparing large-area films. This provides a new approach for the large-scale, high-efficiency production of perovskite films, which holds significant significance and broad application prospects in the renewable energy sector.

[0008] In one aspect, the present invention provides a large-area perovskite film, which is prepared by coating and annealing a perovskite precursor solution; the perovskite precursor solution contains FAI, PbI2, MACl and a solvent; the solvent is selected from one or more of GVL, NMP and GBL; the area of ​​the large-area perovskite film is 100 to 10,000 cm 2 .

[0009] Preferably, the area of ​​the large-area perovskite film is 400 to 5000 cm 2 .

[0010] Preferably, the non-uniformity U of the large-area perovskite film is ≤5%. More preferably, the non-uniformity U of the large-area perovskite film is ≤4%. Further preferably, the non-uniformity U of the large-area perovskite film is ≤3%.

[0011] Preferably, the coating method is selected from slit coating, blade coating, screen printing, spray coating or spin coating.

[0012] More preferably, the film coating is performed by blade coating.

[0013] Preferably, the annealing method is selected from hot stage annealing, oven annealing or crystallization furnace annealing.

[0014] More preferably, the annealing method is hot stage annealing.

[0015] In one or more embodiments, the solvent is a mixture of GVL and NMP.

[0016] Preferably, in the mixed solution of GVL and NMP, the volume ratio of GVL to NMP is (10-1):1.

[0017] More preferably, in the mixed solution of GVL and NMP, the volume ratio of GVL to NMP is 8:1.

[0018] In one or more embodiments, the solvent is a mixture of GVL and GBL.

[0019] Preferably, in the mixed solution of GVL and GBL, the volume ratio of GVL to GBL is (1-2):(1-2).

[0020] More preferably, in the mixed solution of GVL and GBL, the volume ratio of GVL to GBL is 6:4.

[0021] In one or more embodiments, the area of ​​the large-area perovskite film is 400 to 3000 cm 2 .

[0022] Preferably, the area of ​​the large-area perovskite film is 900 to 2400 cm 2 .

[0023] In one or more embodiments, the molar ratio of FAI, PbI2, and MAC1 in the perovskite precursor solution is

[0024] In another aspect, the present invention provides a method for preparing a large-area perovskite film according to any embodiment of the present invention, the method comprising the following steps:

[0025] S1: prepare perovskite precursor solution;

[0026] S2: coating film;

[0027] S3: Annealing.

[0028] Preferably, the area of ​​the large-area perovskite film is 400 to 3000 cm 2 More preferably, the area of ​​the large-area perovskite film is 900 to 2400 cm 2 .

[0029] Preferably, the non-uniformity U of the large-area perovskite film is ≤5%. More preferably, the non-uniformity U of the large-area perovskite film is ≤4%. Further preferably, the non-uniformity U of the large-area perovskite film is ≤3%.

[0030] Preferably, the step S1 comprises adding FAI, PbI2, and MACl into a solvent to obtain a perovskite precursor solution.

[0031] More preferably, the molar ratio of FAI, PbI2, and MACl is 1:1:0.4.

[0032] More preferably, the solvent is a mixture of GVL and NMP. Further preferably, in the mixture of GVL and NMP, the volume ratio of GVL to NMP is (10-1):1. Further preferably, in the mixture of GVL and NMP, the volume ratio of GVL to NMP is 8:1.

[0033] More preferably, the solvent is a mixture of GVL and GBL. Further preferably, in the mixture of GVL and GBL, the volume ratio of GVL to GBL is (1-2):(1-2). Further preferably, in the mixture of GVL and GBL, the volume ratio of GVL to GBL is 6:4. Preferably, the coating method is selected from slit coating, blade coating, screen printing, spray coating, or spin coating.

[0034] More preferably, the coating method is knife coating. Further preferably, during the knife coating process, the coating speed is 30-40 mm / s, the slit gap is 80 μm-150 μm, the solution flow rate is 30-40 μL / s, and the ambient humidity is 5-20%.

[0035] Preferably, the annealing method is selected from hot stage annealing, oven annealing or crystallization furnace annealing.

[0036] More preferably, the annealing method is hot stage annealing. Further preferably, the annealing temperature during the hot stage annealing process is 100-150° C., and the annealing time is 30-60 minutes.

[0037] In another aspect, the present invention provides a solar cell module, comprising the large-area perovskite thin film according to any one of the embodiments of the present invention.

[0038] In one or more embodiments, the solar cell module is composed of a conductive glass layer, a hole transport layer, a self-assembled monolayer, an electron transport layer, an electrode layer and the large-area perovskite film described in any embodiment of the present invention.

[0039] In another aspect, the present invention provides a use of a large-area perovskite film as described in any embodiment of the present invention in preparing a solar cell module.

[0040] In another aspect, the present invention provides use of the solar cell assembly according to any embodiment of the present invention in photovoltaic power generation.

[0041] The present invention achieves at least one beneficial effect as follows:

[0042] 1. Environmentally friendly

[0043] Different from traditional non-green solvents, the green solvent systems GVL / NMP and GBL / GVL provided by the present invention can effectively reduce pollution, improve production safety, and reduce carbon emissions and waste generation during the production process.

[0044] 2. Improve film quality

[0045] The good compatibility between the green solvent systems GVL / NMP and GBL / GVL provided by the present invention and the perovskite components is beneficial to ensuring the stability of the precursor solution and making the grain growth more uniform and dense, thereby facilitating the formation of high-quality and high-performance perovskite films.

[0046] 3. Broaden the operating window

[0047] The green solvent systems GVL / NMP and GBL / GVL provided by the present invention can significantly improve the stability of perovskite, facilitate the storage and transportation of solutions in large-scale production, and provide more time and space for parameter optimization for thin film preparation.

[0048] 4. Reduce production costs

[0049] The green solvents GVL, NMP and GBL used in the present invention are widely available and inexpensive, which is beneficial to reducing the cost of raw materials for preparing perovskite thin films and improving the economic efficiency of production. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a structural diagram of a perovskite solar cell module (PSM).

[0051] Figure 2 This is a schematic diagram of the preparation process of PVSK solution.

[0052] Figure 3 Schematic diagram of the PVSK slit coating and annealing process.

[0053] Figure 4 This is the characteristic diagram of the perovskite film of the GVL / NMP system. Figure 4 a in the figure is the visual observation of the appearance of the perovskite film of the GVL / NMP system; Figure 4 b is the SEM observation of the perovskite film of the GVL / NMP system; Figure 4 Figure c is the SEM observation of the cross section of the perovskite film of the GVL / NMP system; Figure 4 Figure d is the coating thickness distribution diagram of the perovskite film in the GVL / NMP system.

[0054] Figure 5 This is the characteristic diagram of the perovskite film of the GBL / GVL system. Figure 5a in the figure is the visual observation of the appearance of the perovskite film of the GBL / GVL system; Figure 5 b is the SEM observation of the perovskite film of the GBL / GVL system; Figure 5 Figure c is the SEM observation of the cross section of the perovskite film of the GBL / GVL system; Figure 5 d in the figure is the coating thickness distribution diagram of the perovskite film of the GBL / GVL system.

[0055] Figure 6 This is the characteristic diagram of the perovskite film in the DMF / NMP system. Figure 6 a in the figure is the visual observation of the appearance of the perovskite film in the DMF / NMP system; Figure 6 b is the SEM observation of the perovskite film in the DMF / NMP system; Figure 6 Figure c is the SEM observation of the cross section of the perovskite film in the DMF / NMP system; Figure 6 Figure d is the coating thickness distribution diagram of the perovskite film in the DMF / NMP system.

[0056] Figure 7 This is a visual observation of the appearance of PSM using the GVL / NMP system. Figure 7 a in the figure is 300×300mm 2 Visual observation of the appearance of the dimensional PSM; Figure 7 b in the figure is 400×600mm 2 Dimensions Visual observation of the appearance of PSM.

[0057] Figure 8 This is a performance test chart of PSM using GVL / NMP system and GBL / GVL system. Figure 8 Figure a is a performance test diagram of PSM using the GVL / NMP system; Figure 8 Figure b is a performance test diagram of PSM using the GBL / GVL system. DETAILED DESCRIPTION

[0058] In the present invention, “large area” refers to a large area of ​​a perovskite solar cell module (PSM). Preferably, the area of ​​the PSM is 100 to 10,000 cm 2 .

[0059] In the present invention, PSM has Figure 3 The typical sandwich structure shown is composed of conductive glass (TCO glass), hole transport layer (HTL), self-assembled monolayers (SAMs), green solvent-based perovskite layer (PVSK), electron transport layer (ETL) and electrode layer (CE).

[0060] In the present invention, the conductive glass (TCO glass) serves as the carrier of the battery, providing physical support. Like the electrode layer, it also performs the electrical function of collecting electrons or holes from the transport layer and conducting them into the circuit. In the present invention, the TCO comprises one or more of fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and tungsten-doped tin oxide (IWO). Preferably, in the present invention, the TCO comprises ITO. More preferably, in the present invention, the TCO consists of ITO. Preferably, the conductive glass in the present invention is prepared by physical vapor deposition.

[0061] In the present invention, the hole transport layer (HTL) is used to receive holes generated by the perovskite layer, quickly collect and guide the transport of holes; at the same time, it provides a good substrate for the growth of subsequent layers, and can also adjust the electric field distribution inside the battery, reasonably guide the movement direction of charges, and improve the operating efficiency of the battery. In the present invention, the HTL comprises one or both of NiOx and poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA). Preferably, in the present invention, the HTL comprises NiOx. More preferably, in the present invention, the HTL consists of NiOx. Preferably, the HTL in the present invention is prepared by physical vapor deposition.

[0062] In the present invention, the self-assembled monolayer (SAMs) layer can form an interface dipole between the perovskite layer and the electrode layer. These dipoles can effectively regulate the energy level arrangement at the interface. In the present invention, the SAMs include one or both of (2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl)phosphonic acid (Me-2PACz) and [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz). Preferably, in the present invention, the SAMs include Me-2PACz. More preferably, in the present invention, the SAMs consist of Me-2PACz. In the present invention, the coating method of the self-assembled monolayer is selected from one or more of slit coating, blade coating, screen printing, spray coating and spin coating. In the present invention, the coating method of the self-assembled monolayer is selected from annealing treatment methods such as a hot stage, an oven, and a crystallization furnace.

[0063] In the present invention, the perovskite (PVSK) layer is the core part of the device, responsible for absorbing sunlight and generating electron-hole pairs; preferably, the present invention prepares the perovskite layer based on a green solvent system, which not only obtains high-quality PVSK films but also meets the requirements of a non-toxic and environmentally friendly process. In the present invention, the coating method of the perovskite layer is selected from one or more of slit coating, blade coating, screen printing, spray coating and spin coating. In the present invention, the coating method of the perovskite layer is selected from annealing treatment methods such as hot plates, ovens, and crystallization furnaces to complete the phase transition and crystallization process of the perovskite and obtain a fully covered perovskite film. Preferably, the coating method of the perovskite layer in the present invention is blade coating.

[0064] In the present invention, the function of the electron transport layer (ETL) is to extract the photogenerated electrons in the PSVK layer so that the electrons are smoothly transported from the ETL layer to the electrode. In the present invention, the ETL comprises fullerene (C 60 ) and bathocuproine (BCP) in one or both. Preferably, in the present invention, the ETL consists of fullerene and bathocuproine.

[0065] Electrode layer (CE): The presence of electrodes enables the battery to connect effectively to an external circuit. Through appropriate contact and connection methods, the current generated by the battery can be conducted from the copper electrodes to an external load, providing power to the external device. In the present invention, the CE comprises one or more of gold (Au), silver (Cu), copper (Cu), FTO, ITO, and IWO. Preferably, in the present invention, the CE comprises Cu and ITO. More preferably, in the present invention, the CE consists of Cu and ITO.

[0066] Example 1: Preparation process of perovskite thin film in PSM based on green solvent system

[0067] This embodiment uses a green solvent-based perovskite precursor solution to prepare a large-area perovskite film in a PSM. The green solvent is preferably a combination of one or more of γ-butyrolactone (GBL), γ-valerolactone (GVL), and monomethyldipyrrolidone (NMP).

[0068] γ-Butyrolactone has good solubility and is biodegradable by microorganisms in the natural environment; γ-Valerolactone is a renewable resource with good chemical and thermal stability; and methyldipyrrolidone is highly recyclable, has low toxicity, and is more environmentally friendly, meeting the requirements of sustainable development. In large-area PSMs, these green solvents can significantly improve the storage stability of precursor solutions, broaden the operating window for crystallization control, and simplify the preparation process, all while maintaining the quality of perovskite films.

[0069] (1) Preparation of perovskite precursor solution

[0070] Perovskite precursor solution preparation process Figure 2 The specific steps are as follows:

[0071] S1: Weigh FAI (formamidine hydroiodide), PbI2 (lead iodide) and MACl (methylammonium chloride) in a molar ratio of 1:1:0.4 as perovskite precursor materials.

[0072] S2: Prepare a green solvent system, add the perovskite precursor material to the green solvent system, and stir at room temperature overnight to obtain a perovskite precursor solution. The green solvent system is a GVL / NMP system or a GBL / GVL system. The volume ratio of GVL / NMP in the GVL / NMP system is 8:1; the volume ratio of GBL / GVL in the GBL / GVL system is 6:4.

[0073] (2) Preparation of perovskite films

[0074] The preparation process of PVSK layer (i.e. perovskite thin film layer) is as follows Figure 3 The specific method is as follows:

[0075] The perovskite precursor solution obtained in (1) is coated onto the substrate covered with the SAMs layer using a slit coating knife by blade coating; the wet film with an ideal film thickness can be adjusted by controlling the liquid feeding amount and film forming parameters; after the coating is completed, the perovskite is subjected to annealing treatment such as a hot plate to complete the phase change and crystallization process of the perovskite, thereby obtaining a fully covered perovskite film.

[0076] Example 2: Perovskite film based on GVL / NMP system

[0077] Perovskite films based on the dual green solvents GVL and NMP were prepared using the method of Example 1. Their appearance and microstructure were observed using a scanning electron microscope (SEM), and their coating uniformity was measured. U represents a quantitative indicator of film thickness uniformity, representing the percentage of film thickness non-uniformity. The value of U is negatively correlated with film thickness uniformity; U is calculated using the formula U = [(MAX - MIN) / (MAX + MIN)] × 100%.

[0078] Depend on Figure 4 As can be seen from a in the figure, the surface of the perovskite film based on the GVL / NMP system is flat and smooth, showing a metallic luster and transparent texture. Figure 4 As can be seen in b, the perovskite grains in the film present regular or irregular polyhedron shapes, with a grain size of about 600nm. The grains are closely connected to each other, forming a dense network structure with clearly discernible grain boundaries. The overall flatness is good, with no obvious macro defects such as holes or cracks. Figure 4 As can be seen from the image c, the film presents a clear multilayer structure with distinct boundaries between the layers; the perovskite layer presents a dense granular stacking morphology with particles tightly bound together and an average thickness of about 608nm. Figure 4 As can be seen from d in the figure, the thickness of the film from the coating starting position (starting edge) to the coating direction is relatively uniform, and the uniformity U% is only 4.03%.

[0079] In summary, the perovskite film prepared based on the green solvent GVL / NMP has excellent crystallization and uniform thickness.

[0080] Example 3: Perovskite film based on GBL / GVL system

[0081] Perovskite films based on the dual green solvents GBL and GVL were prepared using the method of Example 1. Their appearance and microstructure were observed using SEM, and their coating uniformity was measured. U% is a quantitative indicator of film thickness uniformity, calculated using the formula U% = (MAX - MIN) / (MAX + MIN).

[0082] Depend on Figure 5 As can be seen from a in the figure, it is a perovskite film based on the GBL / GVL system. Figure 5 Figure b is the SEM image of the thin film sample, and the grain size is about 600 nm. Figure 5 Figure c is a SEM image of the film cross section, showing that the particles are tightly bound together and the average thickness is about 600 nm. Figure 5 Figure d is the distribution diagram of the uniformity of the perovskite coating, and the uniformity U% is only 2.83%, achieving excellent crystallization and highly uniform perovskite film.

[0083] Example 4: Perovskite films based on DMF / DMSO and DMF / NMP systems

[0084] Perovskite films based on the dual non-green solvents DMF and DMSO, and perovskite films based on the non-green solvent DMF and the green solvent NMP, were prepared using the method of Example 1. Their appearance and microstructure were observed using SEM, and their coating uniformity was measured. U% is a quantitative indicator of film thickness uniformity, calculated using the formula: U% = (MAX - MIN) / (MAX + MIN).

[0085] The PVSK layer using the DMF / DMSO system cannot undergo a crystalline phase transition in air and therefore cannot be made into a thin film.

[0086] For perovskite films using the DMF / NMP system, Figure 6 As can be seen from a in the figure, there are a lot of holes on the surface of the film, which seriously affect the overall quality of the film. Figure 6 As can be seen in b, the film surface is covered with holes and defects of different sizes, the grain size is significantly different, and the grain boundaries are rough and discontinuous, reflecting that the DMF / NMP system lacks effective control over the perovskite crystal growth process, resulting in many defects in the film. Figure 6 As can be seen from the c in the figure, the thickness of the film layer is about 513nm. Figure 6As shown in Figure d, the perovskite film produced using the DMF / NMP system has a relatively uneven thickness, with a significant difference between the thickest and thinnest locations. The uniformity (U%) is 5.86%. In summary, the perovskite film produced using the DMF / NMP solvent system suffers from poor crystallization quality and poor uniformity.

[0087] Example 4: PSM based on GVL / NMP system and GBL / GVL system

[0088] The structure was prepared by conventional methods such as Figure 3 The PSM shown in FIG. 1 is shown. The PVSK layer is prepared using the same method as in Example 1, using a GVL / NMP system and a GBL / GVL system as solvents, respectively. The PVSK layer is coated at a speed of 30-40 mm / s, a slit gap of 80 μm to 150 μm, a solution flow rate of 30-40 μL / s, and an ambient humidity of 5-20%. The PVSK layer is annealed on a hot plate at a temperature of 100-150°C for 30-60 minutes.

[0089] Appearance observation

[0090] Referring to the above parameter range, the GVL / NMP system was used to prepare large-area PSMs of two different sizes. The specific parameters are shown in Table 1 below.

[0091]

[0092] Depend on Figure 7 It can be seen that using the GVL / NMP system, for 300×300mm 2 size( Figure 7 , a) and 400×600mm 2 ( Figure 7 , b) PSMs of different sizes can produce perovskite films with excellent crystallization and uniform thickness distribution.

[0093] Performance testing

[0094] The performance parameters of perovskite solar cells are important criteria for evaluating their energy conversion capabilities. Based on the parameter ranges of this example, large-area PSMs were fabricated using both the GVL / NMP system and the GBL / GVL system, and their key performance was tested.

[0095] Depend on Figure 8 As shown in a, the open circuit voltage of the PSM using the GVL / NMP system is 47.925 V and the short circuit current is 0.549 mA / cm 2 , the filling factor is 76.65%, and the photoelectric conversion efficiency reaches 20.17%. Figure 8As shown in Figure b, the open circuit voltage of the PSM using the GBL / GVL system is 46.588 V, the short circuit current is 0.573 mA / cm2, the fill factor is 76.21%, and the photoelectric conversion efficiency reaches 20.34%.

[0096] The above results show that the PSMs using the GVL / NMP system and the GBL / GVL system both exhibit stable performance and can achieve high photoelectric conversion efficiency.

[0097] In summary, the present invention provides two green solvent systems (GVL / NMP and GBL / GVL) suitable for perovskite film formation. The prepared perovskite solution has good solubility and stability, excellent coating performance, and the film prepared therefrom has high phase purity and micron-scale grain size, and can be applied to large areas (>200×200mm 2 ) in the PSM, showing stable photoelectric performance and high photoelectric conversion efficiency.

[0098] The present invention achieves at least one beneficial effect as follows:

[0099] 1. Environmentally friendly

[0100] Different from traditional non-green solvents, the green solvent systems GVL / NMP and GBL / GVL provided by the present invention can effectively reduce pollution and improve production safety. With the improvement of environmental awareness and the increasingly stringent relevant regulations, the use of green solvents is more in line with the requirements of sustainable development, which will help promote the green development of the perovskite solar cell industry and reduce carbon emissions and waste generation in the production process.

[0101] 2. Improve film quality

[0102] The excellent compatibility of the green solvent systems GVL / NMP and GBL / GVL provided by the present invention with perovskite components helps ensure the stability of the precursor solution, thereby facilitating the formation of high-quality perovskite films. These green solvent systems GVL / NMP and GBL / GVL provide more uniform and dense grain growth, reducing the formation of defects and voids, and facilitating the preparation of high-performance, void-free perovskite films with uniform thickness.

[0103] 3. Broaden the operating window

[0104] The green solvent systems GVL / NMP and GBL / GVL provided by the present invention can significantly improve the stability of perovskite, facilitate the storage and transportation of solutions in large-scale production, and provide more time and space for parameter optimization for film preparation, thereby reducing the requirements for process precision and facilitating the controllable preparation of large-area, high-quality perovskite films.

[0105] 4. Reduce production costs

[0106] The green solvents GVL, NMP, and GBL used in the present invention are widely available and inexpensive, which helps reduce the raw material costs for perovskite thin film preparation and improve production economics. Furthermore, the use of green solvents can simplify the preparation process, reducing the complex operations and additional processing steps required by non-green or hazardous solvents during the production process, thereby improving production efficiency and further reducing production costs.

Claims

1. A large-area perovskite film, characterized in that: The large-area perovskite film is prepared by coating and annealing a perovskite precursor solution; the perovskite precursor solution contains FAI, PbI2, MACl and a solvent; the solvent is selected from one or more of GVL, NMP and GBL; the area of ​​the large-area perovskite film is 100 to 10,000 cm 2 .

2. The large-area perovskite film according to claim 1, wherein: The solvent is a mixture of GVL and NMP.

3. The large-area perovskite film according to claim 1, wherein: The solvent is a mixture of GVL and GBL.

4. The large-area perovskite film according to claim 1, wherein: The area of ​​the large-area perovskite film is 400 to 3000 cm 2 .

5. The large-area perovskite film according to claim 1, wherein: In the perovskite precursor solution, the molar ratio of FAI, PbI2, and MACl is 1:1:0.

4.

6. A method for preparing a large-area perovskite film according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: S1: prepare perovskite precursor solution; S2: coating film; S3: Annealing.

7. A solar cell module, characterized in that: The solar cell module comprises the large-area perovskite thin film according to any one of claims 1 to 5.

8. The solar cell assembly according to claim 7, wherein The solar cell assembly consists of a conductive glass layer, a hole transport layer, a self-assembled monolayer, an electron transport layer, an electrode layer and the large-area perovskite film according to any one of claims 1 to 5.

9. Use of the large-area perovskite film according to any one of claims 1 to 5 in the preparation of a solar cell module.

10. Use of the solar cell assembly according to claim 7 or 8 in photovoltaic power generation.

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