Method for preparing perovskite thin film, perovskite battery and method for manufacturing same

Abstract

The application relates to the technical field of batteries, and discloses a preparation method of a perovskite film, a perovskite battery and a manufacturing method thereof. The preparation method of the perovskite film comprises the following steps: depositing an inorganic substrate layer on the surface of a battery substrate, wherein the inorganic substrate layer comprises a first inorganic salt material; coating a compensation solution on the surface of the inorganic substrate layer, and forming a composite inorganic substrate layer after drying and annealing treatment, wherein the compensation solution comprises a second inorganic salt material and a loosening agent; and coating an organic salt solution on the surface of the composite inorganic substrate layer, and forming a perovskite film after drying and annealing treatment. The technical scheme provided by the application can solve the problems of poor element proportion regulation of the perovskite film, incomplete reaction caused by dense film layers and uncontrollable film layer morphology in the related art, and effectively improves the film forming quality of the perovskite film.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a preparation method of perovskite thin film, a perovskite battery and a manufacturing method thereof. BACKGROUND

[0002] In the preparation process of perovskite thin film, the two-step film forming method is widely used due to its good controllability and repeatability. The two-step film forming method is to first deposit an inorganic substrate layer on the surface of the substrate, and then coat an organic salt solution on the inorganic substrate layer to generate a perovskite thin film.

[0003] However, the two-step film forming process currently used in applications still has certain technical defects: the element proportion of the inorganic substrate layer is poorly controllable, and the film layer is usually too dense, which makes it difficult for the organic salt solution to penetrate and fully react, limiting the film forming quality of the perovskite thin film and affecting the photoelectric performance and stability of the perovskite thin film. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of perovskite thin film, a perovskite battery and a manufacturing method thereof, for improving the film forming quality of the perovskite thin film.

[0005] The first aspect of the present application provides a preparation method of perovskite thin film, comprising: depositing an inorganic substrate layer on the surface of a battery substrate, the inorganic substrate layer comprising a first inorganic salt material; coating a compensation solution on the surface of the inorganic substrate layer to form a composite inorganic substrate layer after drying and annealing treatment, the compensation solution comprising a second inorganic salt material and a loose agent; coating an organic salt solution on the surface of the composite inorganic substrate layer to form a perovskite thin film after drying and annealing treatment.

[0006] The preparation method provided by the present application introduces a compensation solution and forms a composite inorganic substrate layer before coating the organic solution, on the one hand, the compensation solution comprises a second inorganic salt material, the introduction of the second inorganic salt material can realize the accurate doping and control of inorganic components, which is conducive to the formation of a multi-component perovskite system with consistent composition, uniform element distribution and stable performance, on the other hand, the compensation solution also comprises a loose agent, the introduction of the loose agent can improve the morphology of the inorganic substrate layer and form a porous structure, so that the organic salt solution can penetrate into the composite inorganic substrate layer more fully and react, reducing the residual unreacted precursors, thereby the preparation method can effectively improve the crystalline quality, component uniformity and stability of the perovskite thin film, and improve the performance of the perovskite thin film and the photoelectric device containing the perovskite thin film.

[0007] In some embodiments, the first inorganic salt material comprises AX and BX2, A is a monovalent metal cation comprising at least one of cesium, rubidium, B is a divalent metal cation comprising at least one of lead, tin, X is a monovalent anion comprising at least one of halogen and halogen-like, halogen comprising at least one of iodine, bromine, chlorine; the second inorganic salt material comprises at least one of CsI, PbI2, CsBr, RbI, SnI2, PbBr2, RbBr, CsCl.

[0008] In some embodiments, the first inorganic salt material comprises PbI2 and CsBr, and the ratio of the two is 10:1; the second inorganic salt material comprises PbI2 and CsBr, and the ratio of the two is 1:1.

[0009] In some embodiments, the mass concentration of the second inorganic salt material in the compensation solution is 0.1 mg / mL-30 mg / mL.

[0010] In some embodiments, the bulking agent comprises at least one of dimethyl sulfone, N,N-dimethylformamide, N-methyl pyrrolidone.

[0011] In some embodiments, the mass percentage of the bulking agent in the compensation solution is 0.1%-20%.

[0012] In some embodiments, the solvent of the compensation solution comprises any one of isopropyl alcohol, ethanol, n-butanol.

[0013] In some embodiments, the inorganic substrate layer is deposited on the surface of the battery substrate by a dual-source vapor deposition method.

[0014] Embodiments of the second aspect of the application provide a preparation method of a perovskite battery, comprising: providing a silicon substrate, the silicon substrate comprising a first surface and a second surface arranged oppositely; making a first transparent electrode layer and a first metal electrode layer arranged in sequence on the first surface of the silicon substrate; making a second transparent electrode layer, a first carrier transport layer, a passivation layer, a perovskite thin film, a second carrier transport layer, a third transparent electrode layer and a second metal electrode layer arranged in sequence on the second surface of the silicon substrate, wherein the perovskite thin film is made by the preparation method of the first aspect.

[0015] The preparation method of the perovskite battery provided by the embodiments of the application can improve the quality of the perovskite thin film by making the perovskite thin film by the preparation method of the first aspect, thereby improving the photoelectric performance and stability of the perovskite battery.

[0016] The embodiment of the third aspect of the application provides a perovskite battery, which comprises a first metal electrode layer, a first transparent electrode layer, a silicon substrate, a second transparent electrode layer, a first carrier transport layer, a passivation layer, a perovskite thin film, a second carrier transport layer, a third transparent electrode layer and a second metal electrode layer which are sequentially stacked in a thickness direction, and the perovskite thin film is made by the preparation method of the first aspect.

[0017] The perovskite battery provided by the embodiment of the application has the perovskite thin film made by the preparation method of the first aspect, so that the photoelectric performance and stability of the battery are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 The flow chart of the preparation method of the perovskite thin film provided by the embodiment of the application is shown in the figure.

[0020] Figure 2 The flow chart of the preparation method of the perovskite battery provided by the embodiment of the application is shown in the figure.

[0021] Figure 3 The structure schematic diagram of the perovskite battery provided by the embodiment of the application is shown in the figure.

[0022] Figure 4 The test result diagram of the first group of test experiments of the application is shown in the figure.

[0023] Figure 5 The test result diagram of the embodiment in the second group of test experiments of the application is shown in the figure.

[0024] Figure 6 The test result diagram of Comparative Example 1 in the second group of test experiments of the application is shown in the figure.

[0025] Figure 7 The test result diagram of Comparative Example 2 in the second group of test experiments of the application is shown in the figure.

[0026] Figure 8 The test result diagram of the third group of test experiments of the application is shown in the figure.

[0027] Main element symbol explanation:

[0028] 1000, perovskite battery;

[0029] 1, silicon substrate; 21, first transparent electrode layer; 22, first metal electrode layer; 3, second transparent electrode layer; 4, first carrier transport layer; 5, passivation layer; 6, perovskite thin film; 7, second carrier transport layer; 81, third transparent electrode layer; 82, second metal electrode layer. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0031] It should be noted that when a component is referred to as being "fixed to" or "set to" another component, it can be directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the patent. The terms "first", "second" are only for the purpose of convenient description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0032] In the present application, the reference "one embodiment", "some embodiments" or "embodiments" means that in one or more embodiments of the present application, the specific features, structures or characteristics described in connection with the embodiment are included. Therefore, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in other some embodiments" and the like appearing in different places in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. In addition, in one or more embodiments, specific features, structures or characteristics can be combined in any suitable manner.

[0033] In a first aspect, the embodiments of the present application provide a preparation method of a perovskite thin film 6.

[0034] Please refer to Figure 1 and Figure 3 The preparation method provided by the embodiments of the present application comprises:

[0035] S110, depositing an inorganic substrate layer on the surface of the battery substrate, the inorganic substrate layer comprising a first inorganic salt material.

[0036] The battery substrate is the bottom substrate used to mount the perovskite thin film 6. For example, the perovskite battery 1000 includes a first metal electrode layer 22, a first transparent electrode layer 21, a silicon substrate 1, a second transparent electrode layer 3, a first carrier transport layer 4, a passivation layer 5, a perovskite thin film 6, a second carrier transport layer 7, a third transparent electrode layer 81, and a second metal electrode layer 82, which are stacked sequentially. The battery substrate may be composed of the first metal electrode layer 22, the first transparent electrode layer 21, the silicon substrate 1, the second transparent electrode layer 3, the first carrier transport layer 4, and the passivation layer 5.

[0037] There are many ways to deposit inorganic substrates, such as vapor deposition, spin coating, inkjet printing, slot coating, etc.

[0038] S120. A compensation solution is coated on the surface of an inorganic substrate layer, and after drying and annealing, a composite inorganic substrate layer is formed. The compensation solution includes a second inorganic salt material and a loosening agent.

[0039] Specifically, a compensation solution is coated onto the surface of an inorganic substrate to form a wet film, which is then dried and annealed to obtain a composite inorganic substrate. Understandably, the compensation solution interacts with the inorganic substrate to ultimately combine and form the composite inorganic substrate. The elemental ratios of the composite inorganic substrate are optimized, resulting in a more uniform elemental composition and a three-dimensional interconnected porous structure.

[0040] There are various methods for applying the compensation solution, such as scraping, inkjet printing, slot coating, etc.

[0041] There are many drying methods, such as hot table heating, air blowing drying, vacuum drying, infrared irradiation, flash drying, natural drying, inert gas purging drying, etc.

[0042] The process parameters for annealing are as follows: annealing temperature is limited to 50℃-300℃, annealing time is limited to 5s-2000s, and the annealing atmosphere is air, nitrogen, argon or inert gas protective atmosphere.

[0043] The compensation solution includes a solvent and a second inorganic salt material and a loosening agent dissolved in the solvent. The second inorganic salt material is used to introduce multiple ions to achieve precise and uniform element doping and composition control. The loosening agent is used to regulate the growth and arrangement of inorganic grains during the annealing process, playing a role in creating pores, expanding intergranular gaps, and improving the layered structure. The introduction of the loosening agent can form a porous structure in the composite inorganic substrate layer, providing more permeation channels for the subsequent organic salt solution and providing space for the uniform dispersion of multiple elements.

[0044] S130. An organic salt solution is coated on the surface of the composite inorganic substrate, and after drying and annealing, a perovskite thin film 6 is formed.

[0045] Specifically, an organic salt reaction solution is coated on the surface of a composite inorganic substrate, and after drying, a perovskite pre-crystallized film is formed. Then, the perovskite pre-crystallized film is annealed to obtain a fully reacted perovskite film 6.

[0046] There are various methods for coating organic salt solutions, such as inkjet printing, spin coating, slot coating, etc.

[0047] There are many drying methods, such as hot table heating, air blowing drying, vacuum drying, infrared irradiation, flash drying, natural drying, inert gas purging drying, etc.

[0048] The process parameters for annealing are as follows: annealing temperature is limited to 50℃-300℃, annealing time is limited to 5s-2000s, and the annealing atmosphere is air, nitrogen, argon or inert gas protective atmosphere.

[0049] The method for preparing the perovskite thin film 6 provided in this application introduces a compensation solution and forms a composite inorganic substrate layer before coating with an organic solution. On the one hand, the compensation solution includes a second inorganic salt material. Introducing the second inorganic salt material can achieve precise doping and control of inorganic components, which is beneficial to forming a multi-element perovskite system with consistent composition, uniform element distribution, and stable performance. On the other hand, the compensation solution also includes a loosening agent. Introducing the loosening agent can improve the morphology of the inorganic substrate layer and form a porous structure, so that the organic salt solution can penetrate into the composite inorganic substrate layer more fully and react, reducing the residue of unreacted precursors. Therefore, this preparation method can effectively improve the crystal quality, compositional uniformity, and stability of the perovskite thin film 6, and improve the performance of the perovskite thin film 6 and the optoelectronic devices containing the perovskite thin film 6.

[0050] In some embodiments, the first inorganic salt material comprises AX and BX2, where A is a monovalent metal cation, including cesium (Cs). ＋ ), Rubidium (Rb ＋ At least one of the following, B is a divalent metal cation, including lead (Pb). 2+ ), Tin (Sn) 2+ X is at least one of the following, where X is a monovalent anion, including halogens and halogen-like substances (SCN). - At least one of the following, halogens including iodine (I) - ), bromine (Br - ), chlorine (Cl) - The second inorganic salt material includes at least one of CsI, PbI2, CsBr, RbI, SnI2, PbBr2, RbBr, and CsCl.

[0051] As an example, the first inorganic salt material may include one or more of CsI, CsBr, RbCl, RbI, SnI2, PbBr2, RbBr, CsCl, SnBr2, and SnI2, and be mixed in a certain proportion.

[0052] As an example, the second inorganic salt material may include one or more of CsI, PbI2, CsBr, RbI, SnI2, PbBr2, RbBr, and CsCl, and be mixed in a certain proportion.

[0053] The elements in the first inorganic salt material and the elements in the second inorganic salt material can be the same or different.

[0054] In the above embodiments, the first and second inorganic salt materials have rich element types and can be used to prepare perovskite thin films 6 with multi-element co-doping. At the same time, the element types of the first and second inorganic salt materials are highly matched, and the introduction of supplementary solution can effectively supplement the elemental defects of the inorganic substrate and achieve precise composition control.

[0055] In some embodiments, the first inorganic salt material includes PbI2 and CsBr in a ratio of 10:1; the second inorganic salt material includes PbI2 and CsBr in a ratio of 1:1.

[0056] The ratio of PbI2 to CsBr in the first inorganic salt material / second inorganic salt material refers to the mass ratio.

[0057] Understandably, the proportions of each element in the second inorganic salt material can be adjusted based on the proportions of the elements in the first inorganic salt material and the requirements for film formation on the inorganic substrate.

[0058] In the above embodiments, by adjusting the proportion of each element in the first inorganic salt material, the film quality of the inorganic substrate layer can be improved. By adjusting the proportion of each element in the second inorganic salt material, the missing elements in the inorganic substrate layer can be accurately supplemented, effectively balancing the overall element ratio of the composite substrate layer and achieving composition optimization.

[0059] In some embodiments, the mass concentration of the second inorganic salt material in the compensation solution is 0.1 mg / mL to 30 mg / mL.

[0060] For example, the mass concentration of the second inorganic salt material can be 0.1 mg / mL, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, or 30 mg / mL.

[0061] If the concentration of inorganic salt material in the compensation solution is too low, it may result in insufficient introduction of dopant elements, failing to effectively repair defects in the inorganic substrate layer. Conversely, if the concentration is too high, it may lead to an excess of solute in the solution, causing the precipitation of a large number of crystals during the drying process and affecting the film quality. In the above embodiments, limiting the mass concentration of the second inorganic salt material in the compensation solution to a reasonable range ensures the defect repair and composition optimization capabilities of the compensation solution while reducing the negative impacts of high concentrations.

[0062] In some embodiments, the loosening agent includes at least one of dimethyl sulfone (DMSO), N,N-dimethylformamide (DMF), and N-methylpyrrolidone (NMP).

[0063] Dimethyl sulfone has a moderate boiling point and a slow evaporation rate, which allows it to gradually form uniform and fine pores during drying and annealing, making it suitable for fabricating porous and dense composite inorganic substrates.

[0064] N,N-Dimethylformamide has a low boiling point and a fast evaporation rate, which can quickly form well-connected pores during drying and annealing, making it suitable for situations with short process cycles or thick inorganic substrate layers.

[0065] N-methylpyrrolidone has a high boiling point and a slow evaporation rate, which allows it to form structures with larger pore size and higher porosity during drying and annealing processes, making it suitable for fabricating high-porosity composite inorganic substrates.

[0066] In some embodiments, the mass percentage of the loosening agent in the compensation solution is 0.1%-20%.

[0067] For example, the mass percentage of the loosening agent can be 0.1%, 5%, 10%, 15%, or 20%. Understandably, the mass percentage of the loosening agent is related to factors such as the type of loosening agent and the film structure of the inorganic substrate.

[0068] The mass ratio of the loosening agent in the compensation solution affects the modification effect and process stability. In the above embodiments, by reasonably limiting the proportion of the loosening agent, it is helpful to improve the density, distribution uniformity and connectivity of the pore structure.

[0069] In some embodiments, the solvent of the compensation solution includes any one of isopropanol, ethanol, and n-butanol.

[0070] The solvent can dissolve the second inorganic salt material and the loosening agent, forming a stable compensating solution.

[0071] The solvent provided in the above embodiments can evaporate quickly during the drying and annealing process and is not easy to remain in the composite inorganic substrate layer, thereby avoiding side reactions with the organic salt solution that would affect the quality of the perovskite film 6.

[0072] In some embodiments, the organic salt solution comprises an organic salt material, which includes C(C) ions, where C is a monovalent organic cation, including methylamine (MA) or formamidinium (FA) groups, or phenylethylamine halides (PEA). - X is at least one of the following, where X is a monovalent anion, including halogens and halogen-like substances (SCN). - At least one of the following, halogens including iodine (I) - ), bromine (Br - ), chlorine (Cl) - At least one of the following.

[0073] In some embodiments, the solvent for the organic salt solution includes any one of isopropanol, ethanol, and n-butanol.

[0074] In some embodiments, an inorganic substrate layer is deposited on the surface of the battery substrate using a dual-source vapor deposition method.

[0075] Dual-source vapor deposition refers to placing two inorganic salt materials in independent vacuum evaporation sources. By controlling the parameters of each evaporation source, the two materials are simultaneously sublimated or evaporated into gaseous atoms or molecules, which are then deposited together on the surface of the battery substrate to form a uniform inorganic substrate layer.

[0076] The above design helps to improve the precision of element ratio control in the substrate layer and improve the uniformity of film thickness.

[0077] In summary, the preparation method provided in this application, by introducing a compensation solution, can solve the problems of insufficient penetration, incomplete reaction and multi-component doping in the traditional two-step film formation process, and can prepare dense, uniformly composed, highly stable and high-quality perovskite thin films.

[0078] Secondly, embodiments of this application provide a method for preparing a perovskite solar cell 1000.

[0079] Please refer to Figure 2 and Figure 3 The method for fabricating the perovskite solar cell 1000 provided in this application includes:

[0080] S210. A silicon substrate 1 is provided, the silicon substrate 1 including a first surface and a second surface disposed opposite to each other.

[0081] S220. A first transparent electrode layer 21 and a first metal electrode layer 22 are sequentially stacked on the first side of the silicon substrate 1.

[0082] S230. A second transparent electrode layer 3, a first carrier transport layer 4, a passivation layer 5, a perovskite thin film 6, a second carrier transport layer 7, a third transparent electrode layer 81, and a second metal electrode layer 82 are sequentially stacked on the second side of the silicon substrate 1, wherein the perovskite thin film 6 is fabricated using the preparation method of the embodiments of the first aspect.

[0083] The method for manufacturing the perovskite solar cell 1000 provided in this application improves the quality of the perovskite thin film 6 by using the preparation method of the first aspect, thereby improving the photoelectric performance and stability of the perovskite solar cell 1000.

[0084] Thirdly, embodiments of this application provide a perovskite solar cell 1000.

[0085] Please follow Figure 3 The perovskite solar cell 1000 provided in this application includes a first metal electrode layer 22, a first transparent electrode layer 21, a silicon substrate 1, a second transparent electrode layer 3, a first carrier transport layer 4, a passivation layer 5, a perovskite thin film 6, a second carrier transport layer 7, a third transparent electrode layer 81, and a second metal electrode layer 82, which are sequentially stacked along the thickness direction. The perovskite thin film 6 is fabricated using the preparation methods of the embodiments of the first aspect.

[0086] The perovskite solar cell 1000 provided in this application improves the photoelectric performance and stability of the cell by fabricating a perovskite thin film 6 using the preparation method of the first aspect.

[0087] To verify the technical effects of the perovskite thin film 6 preparation method and the perovskite battery 1000 fabrication method provided in the embodiments of this application, a specific embodiment and two comparative examples are provided below for explanation.

[0088] An embodiment provides a method for manufacturing a perovskite solar cell 1000, comprising the following steps:

[0089] S1: A silicon substrate 1 is provided, the silicon substrate 1 including a first surface and a second surface disposed opposite to each other.

[0090] S2: A first transparent electrode layer 21 is formed on the first side of the silicon substrate 1.

[0091] The first transparent electrode layer 21 can be fabricated using magnetron sputtering, regardless of the location, with the equipment power limited to 10W-400W.

[0092] For example, the first transparent electrode layer 21 is fabricated using magnetron sputtering: the sample is placed in a magnetron sputtering device, an ITO target is set, the power is controlled at 85W, the running time is 0.8h, and the film thickness is 80nm.

[0093] S3: A first metal electrode layer 22 is formed on the side of the first transparent electrode layer 21 away from the silicon substrate 1.

[0094] The first metal electrode layer 22 can be fabricated using vapor deposition, with the vapor deposition vacuum degree limited to 1×10⁻⁶. -5 Pa-1×10 -4 Pa, the evaporation temperature is limited to 200℃-2000℃, and the evaporation rate is limited to 0.1Å / S-5Å / S.

[0095] For example, the first metal electrode layer 22 is fabricated using vapor deposition: the sample is placed on a mask and placed in the vapor deposition chamber, and the vapor deposition vacuum degree is set to 8 × 10⁻⁶. -4 Evaporation is performed at Pa, the evaporation voltage is adjusted to the evaporation temperature, and the evaporation rate is controlled at 1.5 Å / S to deposit silver onto the first transparent electrode layer 21. The evaporation thickness of the silver layer is 120 nm.

[0096] S4: A second transparent electrode layer 3 is fabricated on the second side of the silicon substrate 1.

[0097] The second transparent electrode layer 3 can be fabricated using magnetron sputtering, regardless of the location, with the equipment power limited to 10W-400W.

[0098] For example, the second transparent electrode layer 3 is fabricated using magnetron sputtering: the sample is placed in a magnetron sputtering device, an ITO target is set, the power is controlled at 70W, the running time is 1h, and the film thickness is 40nm.

[0099] S5: A first carrier transport layer 4 is formed on the side of the second transparent electrode layer 3 away from the silicon substrate 1.

[0100] Regardless of location, NIOx can be prepared as the first carrier transport layer 4 on the surface of the second transparent electrode layer 3 using magnetron sputtering, with a film thickness of 8 nm.

[0101] S6: A passivation layer 5 is formed on the side of the first carrier transport layer 4 away from the second transparent electrode layer 3.

[0102] Specifically, Meo-2pacz was dissolved in ethanol to obtain a passivation layer 5 solution with a concentration of 5 mg / mL. Then, the prepared passivation layer 5 solution was coated onto the surface of the first carrier transport layer 4 using a slit coating process. After annealing, the passivation layer 5 was obtained, wherein the annealing temperature was 150 °C and the annealing time was 20 min.

[0103] S7: Deposit an inorganic substrate layer on the surface of the passivation layer 5 away from the first carrier transport layer 4.

[0104] Inorganic substrates can be deposited using processes such as vapor deposition, spin coating, inkjet printing, and slot coating, regardless of the location.

[0105] For example, the inorganic substrate layer includes a first inorganic salt material, which includes PbI2 and CsBr in a ratio of 10:1; the inorganic substrate layer is deposited using a dual-source co-evaporation process, with the evaporation rate controlled at 5 Å / s and the evaporation film thickness at 400 nm.

[0106] S8: A compensation solution is coated on the side of the inorganic substrate layer away from the passivation layer 5 to form a composite inorganic substrate layer.

[0107] Specifically, a compensation solution is prepared, coated on the surface of an inorganic substrate to form a wet film, and then the wet film is dried and annealed to obtain a composite inorganic substrate.

[0108] The preparation of the compensation solution includes: preparing a compensating agent, which includes a second inorganic salt material and a loosening agent; dissolving the second inorganic salt material and the loosening agent in a volatile solvent to form the compensation solution.

[0109] For example, the second inorganic salt material includes PbI2 and CsBr in a 1:1 ratio with a mass concentration of 10 mg / mL. The loosening agent is N,N-dimethylformamide, accounting for 20% by mass, and the solvent is isopropanol. The compensation solution is coated onto the surface of the inorganic substrate using inkjet printing. It is then dried using a hot plate heating method at a temperature of 80°C. After drying, it is annealed at a temperature of 180°C for 300 seconds under an argon protective atmosphere.

[0110] S9: An organic salt solution is coated on the side of the composite inorganic substrate away from the passivation layer 5 to form a perovskite thin film 6.

[0111] Specifically, an organic salt solution is prepared and coated onto the surface of a composite inorganic substrate. After drying, a perovskite pre-crystallized film is formed. The perovskite pre-crystallized film is then annealed to obtain a fully reacted perovskite film 6.

[0112] For example, FAI, MAI, and FABr are mixed in a certain proportion and dissolved in n-butanol to form an organic salt solution with a concentration of 15 mg / mL. The organic salt solution is coated onto the surface of the composite inorganic substrate using inkjet printing, dried by blowing air, and then annealed at a temperature of 120°C for 800 s.

[0113] S10: A second carrier transport layer 7 is fabricated on the side of the perovskite thin film 6 away from the passivation layer 5.

[0114] For example, 34 nm of C60 and 20 nm of SnO2 were sequentially deposited on the surface of the perovskite film 6 using a vapor deposition method.

[0115] S11: A third transparent electrode layer 81 is fabricated on the side of the second carrier transport layer 7 away from the perovskite thin film 6.

[0116] The third transparent electrode layer 81 can be fabricated using magnetron sputtering, regardless of the location, with the equipment power limited to 30W-200W.

[0117] S12: A second metal electrode layer 82 is fabricated on the side of the third transparent electrode layer 81 away from the second carrier transport layer 7.

[0118] The second metal electrode layer 82 can be fabricated using vapor deposition, with the vapor deposition vacuum degree limited to 1×10⁻⁶. -5 Pa-1×10 -4 Pa, the evaporation temperature is limited to 200℃-2000℃, and the evaporation rate is limited to 0.1Å / S-5Å / S.

[0119] For example, the second metal electrode layer 82 is fabricated using vapor deposition: the sample is placed on a mask and placed in the vapor deposition chamber, and the vapor deposition vacuum degree is set to 8 × 10⁻⁶. -4 Evaporation was performed at Pa, the evaporation voltage was adjusted to the evaporation temperature, and the evaporation rate was controlled at 1.5 Å / S to deposit silver onto the third transparent electrode layer 81. The evaporation thickness of the silver layer was 100 nm.

[0120] Comparative Example 1 provides a method for fabricating a perovskite solar cell 1000, which differs from the embodiment in that step S8 is omitted, and the organic salt solution is directly coated on the surface of the inorganic substrate layer.

[0121] Comparative Example 2 provides a method for fabricating a perovskite solar cell 1000. The difference from the embodiment is that step S8 is omitted and step S7 is replaced by: the first inorganic salt material includes PbI2 and CsBr, and the ratio of the two is 10:1. PbI2 and CsBr are dissolved in a mixed solvent with a DMF:DMSO volume ratio of 10:1. The inorganic substrate layer is prepared by a slot coating process.

[0122] Firstly, the thickness of the perovskite thin film 6 prepared in the examples and comparative examples was measured using a profilometer, and the film thickness distribution was statistically analyzed. The statistical results are shown in the appendix of the instruction manual. Figure 4 .

[0123] Comparing the examples and Comparative Examples 1 and 2, it can be seen that using the vapor deposition process to prepare the inorganic substrate layer can effectively improve the uniformity of the perovskite film thickness 6.

[0124] Secondly, using EDS elemental analysis, the content distribution of four elements—Pb, I, Cs, and Br—in the inorganic substrates prepared in the examples and comparative examples was tested. The test results are shown in the appendix of the instruction manual. Figures 5-7 .

[0125] Comparing Comparative Example 1 and Comparative Example 2, it can be seen that when using the slot coating process to fabricate the inorganic substrate, the element ratio within the film layer is more uniform.

[0126] Comparative examples and Comparative Example 1 show that the uniformity of the vapor deposition element ratio distribution of the composite inorganic substrate obtained after adding the compensation solution is improved.

[0127] Thirdly, the perovskite thin film 6 prepared in the examples and comparative examples was tested using photoluminescence (PL) spectroscopy. Specifically, the excitation wavelength was set to 450 nm, the detection range was 700–900 nm, and the testing environment was a nitrogen atmosphere. The test results are shown in the appendix of the instruction manual. Figure 8 .

[0128] The PL characteristics of the embodiment show high-intensity and uniformly distributed in-plane PL luminescence. Specifically, the uniform elemental ratio of the composite inorganic substrate layer in the embodiment provides an ideal nucleation and growth substrate for the uniform and dense crystallization of the perovskite film 6, resulting in a low defect density (such as pinholes and halogen vacancies), which effectively suppresses non-radiative recombination channels and achieves high radiative recombination efficiency. In other words, the fabrication method of the embodiment can produce a high-performance, highly uniform perovskite film 6.

[0129] The PL characteristics of Comparative Example 1 show a significantly weaker overall luminescence intensity and uneven brightness, exhibiting a mottled pattern of alternating bright and dark areas. Specifically, the uneven elemental ratio in the inorganic substrate layer of Comparative Example 1 introduces disordered nucleation sites, leading to abnormal perovskite crystal growth and the generation of numerous defect states (such as point defects and grain boundary defects). These defects act as non-radiative recombination centers, severely quenching PL luminescence and causing performance degradation of the perovskite film 6. In other words, the inhomogeneity of the inorganic substrate layer directly degrades the quality of the perovskite film 6, introducing a high density of non-radiative recombination centers and severely impairing the open-circuit voltage and fill factor of the device.

[0130] The PL characteristics of Comparative Example 2 show that the luminescence exhibits a distinct banded intensity distribution highly correlated with the coating traces. Specifically, the solution accumulation during the slit coating process leads to uneven thickness of the inorganic substrate layer, which in turn causes differences in the subsequent crystallization environment of the perovskite (solvent evaporation, crystallization kinetics) within the microscopic region. The crystallinity, coverage, and even band gap of the perovskite may differ between thicker and thinner areas, thus manifesting as periodic fluctuations in PL intensity. In other words, the substrate fabrication process directly affects the film quality of the perovskite thin film 6, requiring further optimization of process parameters to improve issues such as film thickness uniformity.

[0131] Fourthly, the performance of the perovskite solar cells 1000 prepared in the above embodiments and comparative examples was tested using a solar simulator. Specifically, a standard solar intensity calibration was performed on a 1.0 cm² area.2 The test object underwent a long-term IV test, with the starting voltage set to 2V, the cutoff voltage to 0V, and the range to 100mA. The test results were rounded to two decimal places. The test results are as follows:

[0132] Test object Short-circuit current density Jsc(mA / cm2 2 )]]> Open circuit voltage Voc (mV) Fill factor FF (%) Photoelectric conversion efficiency PCE (%) Example 19.25 1.93 80.50 29.12 Comparative example 1 17.85 1.52 79.80 21.65 Comparative example 2 15.10 1.85 76.40 21.33

[0133] The experimental data in the table above show that:

[0134] First, Jsc is strongly correlated with film uniformity and defect density. In the example, the perovskite film 6 is uniform and has few defects, and photogenerated carriers are effectively collected, hence Jsc is the highest. In Comparative Example 1, severe defect recombination and in Comparative Example 2, uneven film thickness leading to obstructed current paths or high local series resistance both reduce carrier collection efficiency and decrease Jsc.

[0135] Second, Voc directly reflects the degree of nonradiative recombination. The sharp drop in Voc in Comparative Example 1 proves that substrate elemental inhomogeneity introduces a large number of defects, which become powerful nonradiative recombination centers, severely lowering Voc. The higher Voc in Comparative Example 2 indicates that its defect density is lower, and recombination is mainly affected by physical morphology.

[0136] Third, the FF (Fluorescence Filter) is related to the series / parallel resistance of the device. In the example, the film is uniform, resulting in low series resistance and high FF. Comparative Example 2 has the lowest FF, which is directly related to its non-uniform physical morphology. Fluctuations in film thickness lead to increased series resistance and local leakage (reduced parallel resistance), thus significantly lowering the FF.

[0137] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for preparing a perovskite thin film, characterized in that, include: An inorganic substrate layer is deposited on the surface of a battery substrate, the inorganic substrate layer comprising a first inorganic salt material; A compensation solution is coated on the surface of the inorganic substrate layer, and after drying and annealing, a composite inorganic substrate layer is formed. The compensation solution includes a second inorganic salt material and a loosening agent. An organic salt solution is coated on the surface of the composite inorganic substrate, and a perovskite film is formed after drying and annealing. The first inorganic salt material includes AX and BX2, where A is a monovalent metal cation, including at least one of cesium and rubidium, B is a divalent metal cation, including at least one of lead and tin, and X is a monovalent anion, including at least one of halogens and halogen-like substances, wherein the halogen includes at least one of iodine, bromine, and chlorine; the second inorganic salt material includes at least one of CsI, PbI2, CsBr, RbI, SnI2, PbBr2, RbBr, and CsCl.

2. The method for preparing perovskite thin films according to claim 1, characterized in that, The first inorganic salt material comprises PbI2 and CsBr, and the ratio of the two is 10:1; the second inorganic salt material comprises PbI2 and CsBr, and the ratio of the two is 1:

1.

3. The method for preparing perovskite thin films according to claim 1, characterized in that, The mass concentration of the second inorganic salt material in the compensation solution is 0.1 mg / mL to 30 mg / mL.

4. The method for preparing perovskite thin films according to claim 1, characterized in that, The loosening agent includes at least one of dimethyl sulfone, N,N-dimethylformamide, and N-methylpyrrolidone.

5. The method for preparing perovskite thin films according to claim 1, characterized in that, The mass percentage of the loosening agent in the compensation solution is 0.1%-20%.

6. The method for preparing perovskite thin films according to claim 1, characterized in that, The solvent of the compensation solution includes any one of isopropanol, ethanol, and n-butanol.

7. The method for preparing perovskite thin films according to claim 1, characterized in that, The inorganic substrate layer is deposited on the surface of the battery substrate using a dual-source vapor deposition method.

8. A method for preparing a perovskite solar cell, characterized in that, include: A silicon substrate is provided, the silicon substrate including a first surface and a second surface disposed opposite to each other; A first transparent electrode layer and a first metal electrode layer are sequentially stacked on the first side of the silicon substrate; A second transparent electrode layer, a first carrier transport layer, a passivation layer, a perovskite thin film, a second carrier transport layer, a third transparent electrode layer, and a second metal electrode layer are sequentially stacked on the second side of the silicon substrate, wherein the perovskite thin film is fabricated using the preparation method described in any one of claims 1-7.

9. A perovskite battery, characterized in that, The material comprises a first metal electrode layer, a first transparent electrode layer, a silicon substrate, a second transparent electrode layer, a first carrier transport layer, a passivation layer, a perovskite thin film, a second carrier transport layer, a third transparent electrode layer, and a second metal electrode layer, which are sequentially stacked along the thickness direction. The perovskite thin film is fabricated using the preparation method described in any one of claims 1-7.

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