Perovskite light absorption layer and preparation method thereof, and perovskite solar cell
By pre-forming a wetting layer on the coating platform, the edge effect in the coating process of perovskite solar cells is solved, and the uniformity of the perovskite absorption layer and the improvement of the photoelectric performance are achieved, which is suitable for the industrial application of perovskite solar cells.
Patent Information
- Application Number
- CN202510975415.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-15
- Publication Date
- 2025-10-03
AI Technical Summary
During the coating process of perovskite solar cells, the edge effect leads to differences in wettability between the liquid film and the coating platform surface, resulting in problems such as liquid breakage, accumulation, shrinkage or uneven thickness, affecting device performance and resource utilization.
A wetting layer is pre-formed on the coating platform. During coating, a wetting solution similar to the perovskite precursor solution is used to ensure that the liquid film spreads smoothly at the edge of the substrate to avoid sudden changes in wettability. A uniform perovskite light-absorbing layer is formed through annealing treatment.
It significantly improves the quality and uniformity of the perovskite light-absorbing layer, enhances the optoelectronic performance and the feasibility of large-scale applications, is low-cost and compatible with existing production lines, and does not require equipment upgrades or major process adjustments.
Smart Images
Figure CN120751912A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of solar cells, and in particular to a perovskite light-absorbing layer and a preparation method thereof, and a perovskite solar cell. Background Art
[0002] Perovskite materials are widely used in perovskite solar cells due to their excellent optoelectronic properties and low cost. However, when coating perovskite materials over large areas of perovskite solar cells, edge effects are an unavoidable and urgent technical challenge that needs to be addressed. Edge effects refer to the problem of coating fluid breaking, accumulation, shrinkage, or uneven thickness at the edges of the film during the coating process due to uneven fluid dynamics, surface tension, and adhesion.
[0003] Currently, during the perovskite film coating process, when the coating head moves to the tail end of the substrate, a "liquid break" phenomenon easily occurs due to the difference in wettability between the liquid film and the coating platform surface. This leads to liquid accumulation or uneven thickness at the tail end, seriously affecting device performance. This process not only affects the quality and uniformity of the perovskite film, restricting its photovoltaic performance and large-scale application, but also partially blocks the substrate edge area from being used as the active area of the device, resulting in resource waste and reduced battery utilization.
[0004] To address the edge effect, some technicians have adjusted coating speed and pressure, but with limited success. Others have optimized the substrate's surface affinity (e.g., plasma treatment), but this process is complex and lacks stability. Others have designed specialized coating head structures, but this is costly and has limited applicability. Therefore, a low-cost, simple, and effective technology to address the edge effect is urgently needed.
[0005] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the Invention
[0006] The present application provides a perovskite light absorbing layer and a preparation method thereof, and a perovskite solar cell to solve or alleviate the above-mentioned technical problems. The preparation method of the perovskite light absorbing layer in the technical solution of the present application can improve the quality and uniformity of the perovskite light absorbing layer.
[0007] In a first aspect, an embodiment of the present application provides a method for preparing a perovskite light absorbing layer, comprising: forming a wetting layer on the coating platform; Placing a substrate on the coating platform, wherein the substrate comprises a first edge and a second edge; and a connecting area on the coating platform connected to the second edge has the wetting layer; coating a perovskite precursor solution on the substrate in a direction from the first edge to the second edge, wherein the perovskite precursor solution reaches the second edge and contacts the wetting layer, thereby forming an initial perovskite light-absorbing layer on the substrate; The initial perovskite light absorbing layer is annealed to form a perovskite light absorbing layer.
[0008] Optionally, forming a wetting layer on the coating platform comprises: Applying a wetting solution on the coating platform and drying the solution to form the wetting layer; wherein the wetting solution comprises a halide and an organic solvent; The halide includes one or both of organic halide and metal halide salt.
[0009] Optionally, the organic halide includes one or more of methylammonium iodide (MAI), formamidine hydroiodide (FAI), methylammonium bromide (MABr), formamidine hydrobromide (FABr), methylammonium chloride (MACl), and formamidine hydrochloride (FACl).
[0010] Optionally, the metal halide salt includes one or more of PbI2, PbCl2, and PbBr2.
[0011] Optionally, the organic solvent includes one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), diphenyl sulfoxide (DPSO), acetonitrile (ACN), ethanol, and isopropanol.
[0012] Optionally, in the wetting solution, the molar concentration of the halide is 0.001 mol / L-3 mol / L.
[0013] Optionally, the wetting solution further comprises one or both of a crystallization regulator and a surfactant.
[0014] Optionally, the crystallization modifier includes one or more of methylamine hydrochloride (MACl), aminoacetamide hydrochloride (AAH), hydantoin, lead acetate (PbAc2), and fluorinated molecules.
[0015] Optionally, the surfactant includes one or more of thiourea, amide, and phosphate.
[0016] Optionally, the width of the wetting layer is greater than or equal to the liquid outlet width of the coating die head, and the length of the wetting layer is 1-10,000,000 mm.
[0017] In a second aspect, an embodiment of the present application provides a perovskite light-absorbing layer, which is formed using the preparation method of the perovskite light-absorbing layer provided by any of the above embodiments.
[0018] In a third aspect, an embodiment of the present application provides a perovskite solar cell, characterized in that it includes the perovskite light-absorbing layer provided in the above embodiment.
[0019] The above technical solution adopted in the embodiments of the present application may have the following advantages: During the perovskite film coating process, a wetting layer is pre-formed on the coating platform to effectively solve the "liquid break" phenomenon caused by the difference in wettability between the liquid film and the coating platform surface, avoiding problems such as liquid accumulation at the tail end or uneven thickness. When the perovskite precursor solution is coated on the tail end of the substrate, the pre-formed wetting layer has similar wetting properties to the perovskite precursor solution, allowing the liquid film to transition smoothly without breaking due to sudden changes in wettability. This significantly improves the quality and uniformity of the perovskite light-absorbing layer, thereby enhancing the photoelectric performance of the perovskite light-absorbing layer and the feasibility of large-scale application. In addition, this method is low-cost, simple and efficient, does not require complex modifications, is compatible with existing production lines, does not require equipment upgrades or major process adjustments, and has good industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.
[0021] Figure 1 is a flow chart of a method for preparing a perovskite light-absorbing layer according to an embodiment of the present application; Figure 2 is a schematic diagram of the layout of the wetting layer of an embodiment of the present application; Figure 3 3 are cross-sectional SEM images of the perovskite light-absorbing layers of Example 1 and Comparative Example 1.
[0022] Description of reference numerals: E. Sample placement area; A. The area on the coating platform connected to the first edge; F. The area on the coating platform connected to the second edge; B. The area on the coating platform connected to the third edge; D. The area on the coating platform connected to the fourth edge; C. The terminal area of coating. DETAILED DESCRIPTION
[0023] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, the sizes of layers, regions, and elements and their relative sizes may be exaggerated for clarity. The same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other unless there is a conflict.
[0024] like Figure 1 As shown, the embodiment of the present application provides a method for preparing a perovskite light absorbing layer, comprising: S100: forming a wetting layer on the coating platform; S200: placing a substrate on a coating platform, wherein the substrate includes a first edge and a second edge; and a connecting area on the coating platform connected to the second edge has a wetting layer; S300: coating a perovskite precursor solution on the substrate in a direction from the first edge to the second edge, wherein the perovskite precursor solution reaches the second edge and contacts the wetting layer, thereby forming an initial perovskite light-absorbing layer on the substrate; S400: performing annealing treatment on the initial perovskite light absorbing layer to form a perovskite light absorbing layer.
[0025] In the embodiment of the present application, during the perovskite thin film coating process, a wetting layer is pre-formed on the coating platform to effectively solve the "liquid cut-off" phenomenon caused by the difference in wettability between the liquid film and the surface of the coating platform, thereby avoiding problems such as liquid accumulation at the tail end or uneven thickness, and significantly improving the quality and uniformity of the perovskite light-absorbing layer, thereby improving the photoelectric performance of the perovskite light-absorbing layer and the feasibility of large-scale application.
[0026] In an optional embodiment, the surrounding areas on the coating platform that are connected to the four sides of the substrate are all provided with a wetting layer. During the perovskite film coating process, the edge area of the substrate is more prone to edge effects such as liquid film breakage, accumulation, shrinkage or uneven thickness due to the different contact mode and force conditions with the coating platform and the middle area. By providing a wetting layer in the surrounding areas connected to the four sides of the substrate, it can be ensured that the edge area of the substrate and the middle area have the same wettability, so that the perovskite precursor solution can also be smoothly spread at the edge of the substrate, avoiding coating defects caused by differences in wettability, and can comprehensively solve the edge effect problem, thereby improving the quality and uniformity of the entire perovskite film.
[0027] In an optional embodiment, a wetting solution is first uniformly coated onto a predetermined area of a coating platform using a doctor blade method, with a coating thickness of 100 μm to 300 μm (e.g., 100 μm, 200 μm, 300 μm). The coating platform coated with the wetting solution is then placed on a hot plate at 50°C to 70°C (e.g., 50°C, 60°C, 70°C) and dried for 30 to 50 minutes (e.g., 30 minutes, 40 minutes, 50 minutes) to form a uniform wetting layer. Next, a substrate (measuring 25 mm x 75 mm) is placed on the coating platform, with the second edge of the substrate aligned with the wetting layer area on the coating platform. Subsequently, a perovskite precursor solution is uniformly coated onto the substrate using a doctor blade method, in a direction from the first edge of the substrate to the second edge, at a speed of 2 mm / s to 10 mm / s (e.g., 2 mm / s, 5 mm / s, 8 mm / s, 10 mm / s). When the perovskite precursor solution reaches the second edge of the substrate, it contacts the preformed wetting layer, forming a continuous liquid film. This avoids the "liquid break" phenomenon and forms a uniform initial perovskite light-absorbing layer on the substrate. Finally, the substrate coated with the initial perovskite light-absorbing layer is annealed on a hot plate at 100°C-150°C (e.g., 100°C, 110°C, 120°C, 130°C, 140°C, 150°C) for 5-20 minutes (e.g., 5 minutes, 10 minutes, 12 minutes, 15 minutes, 20 minutes). The solvent evaporates and the solute crystallizes on the substrate, forming a uniform and dense perovskite light-absorbing layer. The perovskite light-absorbing layer prepared by the preparation method of the present invention has a uniform thickness, a flat and defect-free surface, and uniform grain size.
[0028] In an optional embodiment, the base is a quadrilateral, comprising a first edge and a second edge disposed opposite to each other, and a third edge and a fourth edge disposed opposite to each other. Figure 2 As shown, the substrate is placed in the sample placement area E of the coating platform, with the first edge connected to area A of the coating platform, the second edge connected to area F of the coating platform, the third edge connected to area B of the coating platform, and the fourth edge connected to area D of the coating platform. Area C of the coating platform is the terminal area of the coating. During the coating process, coating is performed from the first edge to the second edge. The area on the coating platform with the wetting layer can be the connecting area F that connects only to the second edge, or it can include the connecting area that connects to at least one of the first edge, the third edge, and the fourth edge, ensuring that at least the connecting area that connects to the second edge has a wetting layer (that is, in addition to area F, it can also include at least one of area A, area B, and area D). For example, if the surrounding areas on the coating platform that connect to the four sides of the substrate all have a wetting layer, the liquid material can be spread more evenly at all edges, reducing the problem of uneven thickness caused by edge accumulation, and a film of uniform thickness can be obtained on the entire substrate.
[0029] In some embodiments, in step S100, forming a wetting layer on a coating platform includes: Applying the wetting solution on a coating platform and drying it to form a wetting layer; wherein the wetting solution comprises a halide and an organic solvent; The halide includes one or both of an organic halide and a metal halide salt.
[0030] In the embodiment of the present application, the composition of the wetting solution used is close to that of the perovskite precursor solution and has a viscosity similar to that of the perovskite precursor solution. When the perovskite precursor solution is applied, the lyophilicity of the substrate is increased, thereby solving the problem of liquid interruption during coating.
[0031] In an optional embodiment, the preparation method of the wetting solution includes: dissolving a halide (organic halide and / or metal halide salt), a crystallization regulator (if any) and a surfactant (if any) in an organic solvent according to a ratio, and stirring at room temperature for 3-5 hours (for example, 3 hours, 4 hours, 5 hours) to obtain a transparent and uniform wetting solution.
[0032] In some embodiments, the organic halide includes one or more of methylammonium iodide (MAI), formamidine hydroiodide (FAI), methylammonium bromide (MABr), formamidine hydrobromide (FABr), methylammonium chloride (MACl), and formamidine hydrochloride (FACl).
[0033] In some embodiments, the metal halide salt includes one or more of PbI2, PbCl2, and PbBr2.
[0034] In some embodiments, the organic solvent includes one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), diphenyl sulfoxide (DPSO), acetonitrile (ACN), ethanol, and isopropanol.
[0035] In some embodiments, the molar concentration of the halide in the wetting solution is 0.001 mol / L-3 mol / L.
[0036] In the wetting solution, when the molar concentration of the halide is between 0.001mol / L and 3mol / L (for example, 0.001mol / L, 0.01mol / L, 0.1mol / L, 0.5mol / L, 1mol / L, 2mol / L, and 3mol / L), the uniformity and stability of the wetting layer can be guaranteed. If the halide concentration is too low, a sufficiently thick and uniform wetting layer may not be formed, resulting in discontinuity or uneven thickness of the wetting layer during the coating process. This will not effectively improve the interaction between the coating platform and the perovskite precursor solution, and thus the edge effect problem cannot be effectively solved. When the halide concentration is too high, the wetting layer may be too thick, making it difficult to evenly coat the coating platform. It may even cause problems such as crystallization during the drying process, affecting the performance and uniformity of the wetting layer.
[0037] In some embodiments, the wetting solution further includes one or both of a crystallization modifier and a surfactant.
[0038] In some embodiments, the crystallization modifier includes one or more of methylamine hydrochloride (MACl), aminoacetamide hydrochloride (AAH), hydantoin, lead acetate (PbAc2), and fluorinated molecules.
[0039] In an optional embodiment, the fluorinated molecule includes one or both of CF3-PEABr and CF3-PEACl.
[0040] These crystallization modifiers can modulate the crystallization of the halide during the wetting layer formation process, resulting in an amorphous, weakly crystalline wetting layer. Compared to dry films, amorphous, weakly crystalline films exhibit better wettability as wet films. In an optional embodiment, the molar concentration of the crystallization modifier in the wetting solution is 0.001 mol / L to 3 mol / L (e.g., 0.001 mol / L, 0.01 mol / L, 0.1 mol / L, 0.5 mol / L, 1 mol / L, 2 mol / L, 3 mol / L).
[0041] In some embodiments, the surfactant includes one or more of thiourea, amide, and phosphate ester.
[0042] These surfactants can assist in coating while reducing the defect states of the wetting layer and passivating ion migration.
[0043] In some embodiments, the width of the wetting layer is greater than or equal to the liquid outlet width of the coating die, and the length of the wetting layer is 1-10,000,000 mm. The length of the wetting layer needs to be determined based on the size of the substrate sample to be coated. If square meter coating is involved, the length of the wetting layer should be adjusted to the actual situation. In a specific embodiment, the width of the wetting layer is 30 mm, the length of the wetting layer is 100 mm, and the liquid outlet width of the coating die is 25 mm.
[0044] An embodiment of the present application provides a perovskite light-absorbing layer, which is formed using the preparation method of the perovskite light-absorbing layer provided by any of the above embodiments.
[0045] An embodiment of the present application provides a perovskite solar cell, comprising the perovskite light-absorbing layer provided in the above embodiment.
[0046] In an optional embodiment, a perovskite solar cell comprises: a substrate, a perovskite light-absorbing layer, an electron transport layer, and electrodes. The substrate comprises a substrate, a conductive layer, and a hole transport layer attached to the substrate surface. The substrate can be glass or a silicon wafer. The conductive layer can be a fluorine-doped SnO2 layer, and the hole transport layer can be a nickel oxide layer (30 nm thick). The substrate can be ultrasonically cleaned for 20 minutes using an activator, deionized water, ethanol, and acetone, followed by drying. After the perovskite light-absorbing layer is formed, C60 (electron transport layer), BCP, and an Ag electrode can be deposited sequentially on the perovskite light-absorbing layer using thermal evaporation.
[0047] In an optional embodiment, the perovskite material in the perovskite light absorbing layer has a three-dimensional structure, and its general structural formula can be: ABX3; wherein A is a monovalent cation, including but not limited to a cesium ion (Cs + ), rubidium ions (Rb + ), methylamino cation (CH3NH3 + ), amidino cation (CH2(NH2)2 + ) is a mixture of one or more of: B is a divalent cation, including but not limited to lead ions (Pb 2+ ), copper ions (Cu 2+ ), zinc ions (Zn 2+ ), gallium ions (Ga 2+ ), tin ions (Sn 2+ ), calcium ions (Ca 2+ ) is a mixture of one or more of: X is a monovalent anion, including but not limited to iodide ion (I - ), bromide ion (Br - ), chloride ion (Cl - ), fluoride ion (F - ), thiocyanate ion (SCN -). The perovskite material can be one or more of at least one of methylamine lead iodide (MAPbI3, CH3NH2PbI3), formamidinium lead iodide (FAPbI3, CH2(NH2)2PbI3), cesium lead iodide (CsPbI3), methylammonium tin iodide (CH3NH3SnI3), cesium tin iodide (CsSnI3), cesium lead bromide (CsPbBr3), methylammonium tin bromide (CH3NH3SnBr3), cesium tin bromide (CsSnBr3), and methylammonium lead bromide (CH3NH3PbBr3). For example, the perovskite material can be methylamine lead iodide, which can be prepared using PbI2 (lead iodide) and CH3NH3I (methylamine iodide).
[0048] The following specific examples further illustrate the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and substance of the present invention, modifications or replacements made to the structure of the present invention are within the scope of the present invention.
[0049] Example 1 The method for preparing the perovskite light absorbing layer of Example 1 comprises: S100a: applying the wetting solution on the coating platform, drying it, and forming a wetting layer on the coating platform; S200a: placing a substrate on a coating platform, wherein the substrate includes a first edge and a second edge; and a connecting area on the coating platform connected to the second edge has a wetting layer; S300a: coating a perovskite precursor solution on the substrate in a direction from the first edge to the second edge, wherein the perovskite precursor solution reaches the second edge and contacts the wetting layer, thereby forming an initial perovskite light-absorbing layer on the substrate; S400a: annealing the initial perovskite light absorbing layer to form a perovskite light absorbing layer; The wetting solution includes halides (organic halides and metal halide salts), organic solvents, crystallization regulators and surfactants; The organic halide is MAI (methylammonium iodide), the metal halide salt is PbI2, the organic solvent is a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the volume ratio of DMF to DMSO is 4:1; in the wetting solution, the molar concentration of MAI is 1.0 mol / L, and the molar concentration of PbI2 is 0.8 mol / L; the crystallization modifier is methylamine hydrochloride (MACl), with a molar concentration of 0.5 mol / L; and the surfactant is thiourea, with a molar concentration of 0.05 mol / L.
[0050] Example 2 The perovskite light absorbing layer of Example 2 was prepared using a preparation method of the perovskite light absorbing layer similar to that of Example 1, except that, in the wetting solution of Example 2, the organic halide was MACl (methylammonium chloride), the metal halide salts were PbI2 and PbCl2, the organic solvent was a mixed solvent of N,N-dimethylformamide (DMF) and acetonitrile (ACN), and the volume ratio of DMF to ACN was 2:1; in the wetting solution, the molar concentration of MACl was 1.0 mol / L, the molar concentration of PbI2 was 1.5 mol / L, and the molar concentration of PbCl2 was 0.5 mol / L; the crystallization modifiers were hydantoin and lead acetate (PbAc2), the molar concentration of Hydantoin was 0.8 mol / L, and the molar concentration of PbAc2 was 0.4 mol / L; and the surfactant was amide with a molar concentration of 0.1 mol / L.
[0051] Example 3 The perovskite light absorbing layer of Example 3 was prepared using a preparation method of the perovskite light absorbing layer similar to that of Example 1, with the only difference being that, in the wetting solution of Example 3, the organic halide was FAI (formamidine hydroiodide), the metal halide was PbI2, the organic solvent was a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the volume ratio of DMF to DMSO was 1:1; in the wetting solution, the molar concentration of the halide FAI was 1.0 mol / L, and the molar concentration of PbI2 was 1.5 mol / L; the crystallization modifier was the fluorinated molecule CF3-PEABr, with a molar concentration of 0.7 mol / L; and the surfactant was a phosphate ester, with a molar concentration of 0.2 mol / L.
[0052] Example 4 The perovskite light absorbing layer of Example 4 was prepared by a method for preparing a perovskite light absorbing layer similar to that of Example 1, except that, in the wetting solution of Example 4, the organic halide was MAI (methylammonium iodide) and FABr (formamidine hydrobromide), the metal halide was PbI2 and PbBr2, the organic solvent was a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), wherein the volume ratio of DMF:DMSO was 3:1; in the wetting solution, the molar concentration of MAI was 0.8 mol / L, and the molar concentration of FABr was 0.8 mol / L. The molar concentration of PbI2 is 0.4 mol / L, the molar concentration of PbBr2 is 0.7 mol / L, and the molar concentration of PbBr2 is 0.3 mol / L; the crystallization regulators are lead acetate (PbAc2) and fluorinated molecule CF3-PEABr, of which the molar concentration of PbAc2 is 0.2 mol / L and the molar concentration of CF3-PEABr is 0.1 mol / L; the surfactant is a mixture of thiourea and phosphate, of which the molar concentration of thiourea is 0.06 mol / L and the molar concentration of phosphate is 0.04 mol / L.
[0053] Example 5 The perovskite light absorbing layer of Example 5 was prepared using a method for preparing a perovskite light absorbing layer similar to that of Example 1, with the only difference being that in the wetting solution of Example 5, the organic halide was MAI (methylammonium iodide) and the organic solvent was isopropyl alcohol; in the wetting solution, the molar concentration of MAI was 1.6 mol / L; the crystallization modifier was the fluorinated molecule CF3-PEACl, with a molar concentration of 0.15 mol / L; and the surfactant was thiourea, with a molar concentration of 0.08 mol / L.
[0054] Example 6 The perovskite light absorbing layer of Example 6 was prepared using a preparation method of the perovskite light absorbing layer similar to that of Example 1, with the only difference being that in the wetting solution of Example 6, the metal halide salt was PbI2, the organic solvent was a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the volume ratio of DMF:DMSO was 3:1; in the wetting solution, the molar concentration of PbI2 was 1.5 mol / L; and the crystallization modifier was aminoacetamide hydrochloride (AAH), and the molar concentration of AAH was 0.2 mol / L.
[0055] Example 7 The perovskite light absorbing layer of Example 7 was prepared using a method for preparing a perovskite light absorbing layer similar to that of Example 1, with the only difference being that in the wetting solution of Example 7, the organic halide was MAI (methylammonium iodide) and FABr (formamidine hydrobromide), and the organic solvent was a mixed solvent of isopropanol and ethanol, wherein the volume ratio of isopropanol to ethanol was 1:1; in the wetting solution, the molar concentration of MAI was 0.8 mol / L, and the molar concentration of FABr was 0.4 mol / L.
[0056] Example 8 The perovskite light absorbing layer of Example 8 was prepared using a method for preparing a perovskite light absorbing layer similar to that of Example 1, except that the wetting solution of Example 8 did not include a surfactant; the organic halide was FAI (formamidine hydroiodide) and MABr (methylammonium bromide), the metal halide was PbI2 and PbBr2, and the organic solvent was a mixed solvent of dimethyl sulfoxide (DMSO) and acetonitrile (ACN), wherein the volume ratio of DMSO to ACN was 3:2; in the wetting solution, the molar concentration of FAI was 1.2 mol / L, the molar concentration of MABr was 0.3 mol / L, the molar concentration of PbI2 was 1.0 mol / L, and the molar concentration of PbBr2 was 0.2 mol / L; the crystallization modifiers were aminoacetamide hydrochloride (AAH) and hydantoin, the molar concentration of AAH was 0.3 mol / L, and the molar concentration of hydantoin was 0.2 mol / L.
[0057] Example 9 The perovskite light absorbing layer of Example 9 was prepared using a preparation method of the perovskite light absorbing layer similar to that of Example 1, except that the wetting solution of Example 9 did not include a crystallization modifier; the organic halide was MACl (methylammonium chloride) and FACl (formamidine hydrochlorate), the metal halide was PbCl2, and the organic solvent was a mixed solvent of ethanol and isopropanol, wherein the volume ratio of ethanol to isopropanol was 3:1; in the wetting solution, the molar concentration of MACl was 0.5 mol / L, the molar concentration of FACl was 0.5 mol / L, and the molar concentration of PbCl2 was 0.4 mol / L; and the surfactant was a mixture of amide and phosphate, wherein the molar concentration of amide was 0.08 mol / L, and the molar concentration of phosphate was 0.05 mol / L.
[0058] Example 10 The perovskite light absorbing layer of Example 10 was prepared using a preparation method of the perovskite light absorbing layer similar to that of Example 1, except that the wetting solution of Example 10 did not include a crystallization regulator and a surfactant; the organic halide was FAI (formamidine hydroiodide), the metal halide was PbI2, and the organic solvent was dimethyl sulfoxide (DMSO); in the wetting solution, the molar concentration of FAI was 0.001 mol / L, and the molar concentration of PbI2 was 0.001 mol / L.
[0059] Comparative Example 1 In order to more clearly illustrate the technical effects of the embodiments of the present application, the present application also provides a preparation method of the perovskite light-absorbing layer of Comparative Example 1, which does not include pre-forming a wetting layer on the coating platform.
[0060] The preparation method of the perovskite light-absorbing layer of Comparative Example 1 comprises: S100b: placing a substrate on a coating platform, the substrate comprising a first edge and a second edge; and no wetting layer is provided on the coating platform; S200b: coating a perovskite precursor solution on the substrate in a direction from the first edge to the second edge; S300b: annealing the initial perovskite light absorbing layer to form a perovskite light absorbing layer.
[0061] The perovskite precursor solution and annealing process in Comparative Example 1 are the same as those in Example 1, respectively.
[0062] This application will use the preparation method of the perovskite light-absorbing layer of Examples 1 to 10 and Comparative Example 1 to form solar cells and prepare corresponding photovoltaic modules, and test the open circuit voltage Voc, short circuit current density Jsc, fill factor FF, and photoelectric conversion efficiency PCE of the corresponding photovoltaic modules. The test results are shown in Table 1.
[0063] Table 1
[0064] It can be seen from the data in Table 1 that, compared with Comparative Example 1, the open circuit voltage, short circuit current density, fill factor and photoelectric conversion efficiency of the photovoltaic modules of Examples 1 to 10 of the present application are improved.
[0065] The present application also tested the perovskite light absorbing layer of Example 1 and Comparative Example 1 by using a step profiler and SEM testing method. The cross-sectional SEM images of the perovskite light absorbing layer of Example 1 and Comparative Example 1 are shown in FIG. Figure 3 shown. Figure 3Figure a is a cross-sectional SEM image of the middle region of the perovskite light absorbing layer of Comparative Example 1, Figure b is a cross-sectional SEM image of the region 0.2 mm from the second edge of the perovskite light absorbing layer of Comparative Example 1, and Figure c is a cross-sectional SEM image of the region 0.2 mm from the second edge of the perovskite light absorbing layer of Example 1. The thickness of the middle region of the perovskite light absorbing layer of Comparative Example 1 was measured to be 613 nm, and the thickness of the region 0.2 mm from the second edge was 941 nm. The thickness of the middle region of the perovskite light absorbing layer of Example 1 was measured to be 614 nm, and the thickness of the region 0.2 mm from the second edge was 624 nm.
[0066] From the above content, it can be seen that the edge portion of the perovskite light-absorbing layer prepared by the method of Comparative Example 1 is thicker, resulting in reduced device performance; while the perovskite light-absorbing layer prepared by the methods of Examples 1-10 of the present application has a uniform thickness (especially significantly improving the problem of rear-end liquid accumulation), thereby improving device performance.
[0067] In summary, in the embodiments of the present application, during the perovskite film coating process, by pre-forming a wetting layer on the coating platform, the "liquid break" phenomenon caused by the difference in wettability between the liquid film and the coating platform surface is effectively solved, and problems such as liquid accumulation or uneven thickness at the tail end are avoided. When the perovskite precursor solution is coated on the tail end of the substrate, because the pre-formed wetting layer has similar wetting properties to the perovskite precursor solution, the liquid film can transition smoothly and will not break due to sudden changes in wettability, significantly improving the quality and uniformity of the perovskite light-absorbing layer, thereby improving the photoelectric performance of the perovskite light-absorbing layer and the feasibility of large-scale application. In addition, this method is low-cost, simple and efficient, does not require complex modifications, has good compatibility with existing production lines, does not require equipment upgrades or major process adjustments, and has good industrial application prospects.
[0068] It should be noted that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting this application. The directional words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.
[0069] It should be noted that the terms "first", "second", "front", "back", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0070] It should also be noted that references to "one embodiment," "another embodiment," "an embodiment," etc., in this application refer to specific features, structures, or characteristics described in conjunction with that embodiment as included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that such feature, structure, or characteristic, when implemented in conjunction with other embodiments, also fall within the scope of this application.
[0071] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0072] It should also be noted that the above are only preferred embodiments of the present application and do not limit the scope of patent protection of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of the present application.
Claims
1. A method for preparing a perovskite light-absorbing layer, characterized in that: include: forming a wetting layer on the coating platform; placing a substrate on the coating platform, the substrate comprising a first edge and a second edge; The connecting area on the coating platform connected to the second edge has the wetting layer; coating a perovskite precursor solution on the substrate in a direction from the first edge to the second edge, wherein the perovskite precursor solution reaches the second edge and contacts the wetting layer, thereby forming an initial perovskite light-absorbing layer on the substrate; The initial perovskite light absorbing layer is annealed to form a perovskite light absorbing layer.
2. The method for preparing a perovskite light absorbing layer according to claim 1, wherein: The step of forming a wetting layer on the coating platform comprises: Applying a wetting solution on the coating platform and drying the solution to form the wetting layer; wherein the wetting solution comprises a halide and an organic solvent; The halide includes one or both of organic halide and metal halide salt.
3. The method for preparing a perovskite light absorbing layer according to claim 2, wherein: The organic halide includes one or more of methylammonium iodide, formamidine hydroiodide, methylammonium bromide, formamidine hydrobromide, methylammonium chloride, and formamidine hydrochloride.
4. The method for preparing a perovskite light absorbing layer according to claim 2, wherein: The metal halide salt includes one or more of PbI2, PbCl2, and PbBr2.
5. The method for preparing a perovskite light absorbing layer according to claim 2, wherein: The organic solvent includes one or more of N,N-dimethylformamide, dimethyl sulfoxide, diphenyl sulfoxide, acetonitrile, ethanol, and isopropanol.
6. The method for preparing a perovskite light absorbing layer according to claim 2, wherein: In the wetting solution, the molar concentration of the halide is 0.001 mol / L-3 mol / L.
7. The method for preparing a perovskite light absorbing layer according to claim 2, wherein: The wetting solution further comprises one or both of a crystallization regulator and a surfactant.
8. The method for preparing a perovskite light absorbing layer according to claim 7, wherein: The crystallization modifier includes one or more of methylamine hydrochloride, aminoacetamide hydrochloride, hydantoin, lead acetate, and fluorinated molecules.
9. The method for preparing a perovskite light absorbing layer according to claim 7, wherein: The surfactant includes one or more of thiourea, amide, and phosphate.
10. The method for preparing a perovskite light absorbing layer according to claim 1, wherein: The width of the wetting layer is greater than or equal to the liquid outlet width of the coating die head, and the length of the wetting layer is 1-10,000,000 mm.
11. A perovskite light-absorbing layer, characterized in that: The perovskite light absorbing layer is formed by the preparation method of any one of claims 1 to 10.
12. A perovskite solar cell, characterized in that: Comprising the perovskite light-absorbing layer as claimed in claim 11.