Preparation method and application of right triangle all-inorganic perovskite nanowire array

Abstract

The invention discloses a preparation method and application of a right triangle full-inorganic perovskite nanowire array, and belongs to the field of perovskite application, the method comprises the following steps: a plane reflection grating is used as a female die, and the surface structure of the plane reflection grating is a right triangle structure; the method comprises the following steps: firstly, carrying out surface modification on the aluminum surface of the plane reflection grating by using perfluorooctyltrichlorosilane, then dispensing a PDMS main agent and a curing agent which are uniformly mixed on the modified surface of the plane reflection grating, and curing to obtain a PDMS soft template of a groove array of which the cross section is a right triangle; finally, under the action of a capillary tube, the perovskite precursor solution is sucked into a triangular channel formed by attaching the PDMS soft template and the target substrate, and the right triangle perovskite nanowire array is formed after heating crystallization. According to the invention, the reusability of the female die is improved, and the cost is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the application field of perovskite, and in particular to a preparation method of a right-angled triangle all-inorganic perovskite nanowire array and its application. Background Art

[0002] Halogen perovskites can be synthesized using a low-cost solution method and have the characteristics of long carrier diffusion length, high light absorption coefficient, and the ability to operate on flexible substrates. After absorbing photons, carriers can be generated in femtoseconds, but the recombination time is as long as microseconds, making them ideal materials for low-light detection. The relatively loose chemical bonds of the organic cations at the A position of the organic-inorganic hybrid perovskite and the low thermal decomposition temperature make the perovskite prone to chemical stability problems when exposed to the atmosphere, humidity, heat, and light environments. Therefore, while exploring strategies to enhance its stability, people have also turned their attention to all-inorganic halogen perovskite photosensitive materials. Using Cs + After replacing the organic group at position A, the formed all-inorganic perovskite exhibits high chemical stability.

[0003] Flat perovskite thin films are the predominant form factor for optoelectronic devices. However, grain boundaries in thin crystal films often serve as scattering sites for electrons and photons, leading to a series of problems such as high defect density and low stability, which significantly hinder device performance improvements. Furthermore, free-standing bulk perovskite single crystals are incompatible with the current trend toward integration and miniaturization of optoelectronic devices. Micro- and nanostructured patterns that enhance light scattering and absorption and reduce light reflection, photonic metasurfaces for two-dimensional topological photonics, and superwettability have become attractive research directions for optoelectronic applications. It has been reported that perovskite micro- and nanostructures are closely related to carrier lifetime and electron-hole recombination. One-dimensional perovskite micro / nanowires are of particular interest due to their larger surface area, well-defined one-dimensional crystal structure, unique crystallographic orientation, and axial / radial optical anisotropy. Consequently, they are less prone to defects and grain boundaries, which reduces carrier recombination rate and shortens recombination time. These properties significantly extend device lifetime and stability. Arranging perovskite wires into ordered arrays with specific locations can further improve current yield and active area. Due to their geometry, they also exhibit remarkable mechanical flexibility, suggesting a promising future for flexible device fabrication. Summary of the Invention

[0004] One of the objectives of the present invention is to provide a method for preparing a right-angled triangle all-inorganic perovskite nanowire array to solve the problems of high defect density and low stability of grain boundaries of crystal films in the prior art.

[0005] The present invention is achieved through the following technical solution, a method for preparing a right-angled triangle all-inorganic perovskite nanowire array, comprising the following steps: S100, modifying the surface of a plane reflection grating, and using the surface-modified plane reflection grating as a master mold, wherein the surface structure of the plane reflection grating is a right-angled triangle structure; S200, mixing a PDMS main agent and a curing agent to prepare a prepolymer, drop-coating the prepolymer on the surface of the master mold to allow it to disperse naturally, and curing to obtain a PDMS spatial confined growth template with a right-angled triangle cross-section, cutting the PDMS spatial confined growth template to obtain a PDMS soft template; S300, adding PbBr to the DMSO liquid. 2. Stir until the PbBr2 powder is completely dissolved to prepare a first mixed solution, add CsBr to the first mixed solution, stir until the CsBr powder is completely dissolved to prepare a second mixed solution, filter the two mixed solutions using a filter membrane syringe to remove undissolved impurities, and prepare a precursor solution; S400, clean the target substrate, and after cleaning, laminate the PDMS soft template and the target substrate, and drop the precursor solution on one side of the triangular channel formed after the PDMS soft template and the target substrate are laminated, and use capillary action to absorb the perovskite precursor solution into the triangular channel, and then heat and crystallize it. After crystallization, remove the PDMS soft template to prepare a perovskite nanowire array.

[0006] Furthermore, the stirring temperature of the first mixed solution and the second mixed solution is 60-70°C.

[0007] Furthermore, the surface material of the planar reflection grating is aluminum. By modifying the surface of the planar reflection grating, the separation smoothness of the master mold and PDMS and the reusability of the master mold are improved. The surface modification of the planar reflection grating is achieved by self-assembling a layer of perfluorooctyltrichlorosilane film on the aluminum surface of the planar reflection grating.

[0008] Furthermore, the surface of the plane reflection grating is modified, including the following sub-steps: S110, placing the plane reflection grating on a polytetrafluoroethylene cleaning rack, placing it in an ethanol solvent and performing a first ultrasonic cleaning, after the first cleaning is completed, using deionized water to perform a second cleaning on the plane reflection grating by a spraying and overflowing method, after the second cleaning is completed, using an acetone solution to perform a third ultrasonic cleaning on the plane reflection grating, and finally using deionized water to perform a fourth cleaning on the plane reflection grating by a spraying and overflowing method; S120, using UV-ozone to treat the plane reflection grating after cleaning to increase the number of surface hydroxyl groups of the plane reflection grating; S130, placing perfluorooctyltrichlorosilane and the plane reflection grating in a vacuum drying oven, and using a vapor deposition method to self-assemble a perfluorooctyltrichlorosilane monolayer film on the surface of the plane reflection grating; S140, after the self-assembly of the perfluorooctyltrichlorosilane monolayer film is completed, placing the plane reflection grating in a muffle furnace for heat treatment.

[0009] Furthermore, the light intensity of UV-ozone treatment was 60 mW / cm 2 , the processing time is 25min.

[0010] Furthermore, the annealing treatment is performed by preheating at 100°C for 30 minutes and then heating to 165°C for annealing for 15 minutes.

[0011] Furthermore, step S200 includes the following sub-steps: Step S200 includes the following sub-steps: S210, mixing the PDMS main agent and the curing agent in a mass ratio of 10:1, and standing in a vacuum negative pressure vacuum drying oven to remove bubbles to obtain a prepolymer; S220, drop-coating the prepolymer on the surface of the master mold, naturally dispersing it evenly under the action of gravity, and using a constant temperature oven for mirror curing, the curing temperature is 60°C, and the curing time is 4 hours to prepare a PDMS spatial confined growth template with a cross-sectional shape of a right triangle; S230, cutting the PDMS spatial confined growth template into a size of 1×1 cm for the growth of perovskite nanowire arrays.

[0012] Furthermore, the target substrate in step S400 is a Si substrate.

[0013] Furthermore, the temperature of the crystallization reaction in step S400 is 70° C., and the reaction time is 45 minutes.

[0014] Furthermore, cleaning the target substrate includes: placing the target substrate on a polytetrafluoroethylene cleaning rack, placing it in an ethanol solvent and ultrasonically cleaning it for 10 minutes; then using deionized water to clean the cleaned Si substrate by a spraying and overflowing method for 10 minutes; then using an acetone solution to ultrasonically clean the cleaned Si substrate for 10 minutes; finally using deionized water to clean the cleaned Si substrate by a spraying and overflowing method for 10 minutes, and after cleaning, using nitrogen to blow dry the target substrate.

[0015] Another aspect of the present invention provides a right-angled triangle all-inorganic perovskite nanowire array, which is prepared according to the method described above.

[0016] The present invention also provides an application of a right-angled triangle all-inorganic perovskite nanowire array, which is prepared according to the method described above, including the following applications: (1) application in preparing flexible perovskite solar cells; (2) application in preparing high current yield perovskite solar cells; (3) application in preparing high active area perovskite solar cells.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] 1. The present invention utilizes a vapor deposition method to self-assemble a trichloro(1H,1H,2H,2H-perfluorooctyl)silane monolayer on the aluminum surface of a master mold, and obtains a surface with a larger contact angle through an annealing process. This surface modification improves the anti-fouling performance and high wettability of the master mold surface without destroying the surface structure of the master mold, facilitates the separation of the PDMS material from the mold, ensures the integrity of the PDMS transfer structure, improves the reusability of the master mold, and greatly reduces costs.

[0019] 2. The present invention uses a solution method for synthesis, which is low-cost, simple and adjustable, and has great potential for large-scale manufacturing and industrialization in optoelectronic devices.

[0020] 3. The right-angled triangle all-inorganic perovskite nanowire array prepared by the present invention has a larger specific surface area, which helps to enhance the scattering and absorption of light. In addition, the one-dimensional linear structure of the parallel arranged perovskite nanowires has good mechanical stability and can be made into flexible devices. The array-shaped nanowire structure facilitates the integrated application of micro-nano optoelectronic devices, which is of great significance for the miniaturization and integration of devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0022] Figure 1 This is a flow chart of the method provided in Example 1 of the present invention.

[0023] Figure 2 This is a contact angle diagram of the aluminum surface after cleaning with ethanol, acetone and deionized water provided in Example 2 of the present invention.

[0024] Figure 3 This is a contact angle diagram of the aluminum surface after UV-ozone treatment provided in Example 2 of the present invention.

[0025] Figure 4 This is a contact angle diagram of the aluminum surface after surface modification with trichloro(1H,1H,2H,2H-perfluorooctyl)silane provided in Example 2 of the present invention.

[0026] Figure 5 This is a contact angle diagram of the modified aluminum surface after heat treatment provided in Example 2 of the present invention.

[0027] Figure 6 This is a SEM top view of the triangular PDMS soft template provided in Example 3 of the present invention.

[0028] Figure 7 This is a SEM side view of the triangular PDMS soft template provided in Example 3 of the present invention.

[0029] Figure 8 This is an SEM image of the perovskite nanowire array provided in Example 3 of the present invention.

[0030] Figure 9 This is a fluorescence micrograph of the perovskite nanowire array provided in Example 3 of the present invention.

[0031] Figure 10 This is the X-ray diffraction (XRD) pattern of the perovskite nanowire array provided in Example 3 of the present invention on a glass substrate.

[0032] Figure 11 This is the PL emission peak diagram of the perovskite nanowire array provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0034] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention pertains. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of this invention. All references mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related thereto. In the event of a conflict with any incorporated reference, the present specification controls. As used herein, the terms "including," "comprising," "having," "containing," and the like are open-ended, meaning to include, but not be limited to, the terms "a," "an," and "an" include plural references unless the context clearly indicates otherwise. It should be noted that the terms "first," "second," and the like are used solely for convenience of description and distinction and are not to be construed as indicating or implying relative importance. As used herein, the term "about" refers to a range of ±20% of the value that follows it. In some embodiments, the term "about" refers to a range of ±10% of the value that follows it. In some embodiments, the term "about" refers to a range of ±5% of the value that follows it.

[0035] Example 1

[0036] Figure 1 The flowchart of the method of this embodiment is shown. It can be seen from the figure that this embodiment includes the following contents:

[0037] Step 1: A plane reflection grating is used as a master mold, wherein the surface structure of the plane reflection grating is a right-angled triangle structure.

[0038] Specifically, the surface material of the planar reflection grating is aluminum. By modifying the surface of the planar reflection grating, the separation smoothness of the master mold and PDMS and the reusability of the master mold are improved. The surface modification of the planar reflection grating is achieved by treating the surface aluminum material of the planar reflection grating with trichlorosilane.

[0039] Specifically, modifying the surface of the planar reflection grating may include the following sub-steps:

[0040] 1) Place the plane reflection grating on a polytetrafluoroethylene cleaning rack and perform a first ultrasonic cleaning in an ethanol solvent. After the first cleaning is completed, perform a second cleaning using deionized water by spraying and overflowing. After the second cleaning is completed, perform a third ultrasonic cleaning using an acetone solution. Finally, perform a fourth cleaning using deionized water by spraying and overflowing.

[0041] 2) Use UV-ozone treatment to clean the planar reflection grating to increase the number of surface hydroxyl groups of the planar reflection grating. The light intensity of UV-ozone treatment is 60mW / cm 2, the processing time is 25min.

[0042] 3) A perfluorooctyltrichlorosilane monolayer was self-assembled on the surface of a planar reflection grating using vapor deposition.

[0043] 4) After deposition, the planar reflection grating was placed in a muffle furnace for heat treatment. The heat treatment consisted of preheating at 100°C for 30 minutes and then annealing at 165°C for 15 minutes.

[0044] Step 2: Mix the PDMS main agent and the curing agent to prepare a prepolymer, and drop the prepolymer on the surface of the master mold to allow it to disperse naturally. After curing, a PDMS spatial confined growth template with a right-angled triangle cross-section is prepared. The PDMS spatial confined growth template is cut to obtain a PDMS soft template.

[0045] Specifically, the following sub-steps may be included:

[0046] 1) PDMS base and curing agent were mixed in a mass ratio of 10:1 and placed in a vacuum drying oven to remove bubbles to obtain a prepolymer.

[0047] 2) The prepolymer was drop-coated onto the master mold surface and evenly dispersed under gravity. The prepolymer was then image-cured in a thermostat at 60°C for 4 hours, resulting in a PDMS spatially confined growth template with a right-angled triangle cross-section.

[0048] 3) Cutting the PDMS spatial confinement growth template into a size of 1×1 cm for the growth of perovskite nanowire arrays.

[0049] Step 3: Add PbBr2 to the DMSO liquid, stir or heat and stir at 70°C until the PbBr2 powder is completely dissolved to prepare a first mixed solution, add CsBr to the first mixed solution, stir or heat and stir at 70°C until the CsBr powder is completely dissolved to prepare a second mixed solution, filter the two mixed solutions using a filter membrane syringe to remove undissolved impurities, and prepare a precursor solution.

[0050] Step 4: S400, cleaning the target substrate, which can be a Si substrate, and the cleaning process is to place the target substrate on a polytetrafluoroethylene cleaning rack, place it in an ethanol solvent and use ultrasonic cleaning for 10 minutes; then use deionized water to clean the cleaned Si substrate by spraying and overflowing for 10 minutes; then use acetone solution to ultrasonically clean the cleaned Si substrate for 10 minutes; finally, use deionized water to clean the cleaned Si substrate by spraying and overflowing for 10 minutes, and after cleaning, use nitrogen to blow dry the target substrate.

[0051] After cleaning, the PDMS soft template is bonded to the target substrate, and the precursor solution is dripped onto one side of the triangular channel formed after the PDMS soft template and the target substrate are bonded. The perovskite precursor solution is sucked into the triangular channel by capillary action, and then heated and crystallized. After crystallization is completed, the PDMS soft template is removed to prepare a titanium ore nanowire array.

[0052] Example 2

[0053] The difference between this embodiment and embodiment 1 is that the surface modification operation on the aluminum surface of the reflection grating master mold is different, and the remaining steps are the same as those in embodiment 1.

[0054] In this embodiment, a method for surface modification of an aluminum surface of a reflection grating master mold using trichloro(1H,1H,2H,2H-perfluorooctyl)silane (PFTCS) is provided. This embodiment includes the following steps:

[0055] Step 1: Clean the plane reflection grating. Place the reflection grating on a polytetrafluoroethylene cleaning rack and ultrasonically clean it in an ethanol solvent for 10 minutes. Then, use deionized water to clean the cleaned plane reflection grating by spraying and overflowing for 10 minutes. Use acetone solution to ultrasonically clean the cleaned plane reflection grating for 10 minutes. Then, use deionized water to clean the cleaned plane reflection grating by spraying and overflowing for 10 minutes.

[0056] like Figure 2 As shown, the contact angle of the master mold surface after cleaning is about 74°.

[0057] Step 2: Increase the number of surface hydroxyl groups and place the plane reflection grating obtained in step 1 under a light intensity of 60 mW / cm 2 UV ozone treatment for 25 minutes under the conditions of Figure 3 As shown, the contact angle of the master mold surface after UV-ozone treatment is about 5°.

[0058] Step 3: Self-assembly of a trichloro(1H,1H,2H,2H-perfluorooctyl)silane monolayer: Place the reflection grating obtained in step 2 and 2 μl of trichloro(1H,1H,2H,2H-perfluorooctyl)silane in a vacuum drying oven and perform vapor deposition for 45 minutes at a temperature of 25°C and a vacuum degree of -80 kPa. Figure 4 As shown in FIG, after vapor deposition of trichloro(1H,1H,2H,2H-perfluorooctyl)silane, the contact angle of the master mold surface is about 106°.

[0059] Step 4: Place the reflection grating obtained in step 3 in a muffle furnace, preheat at 100°C for 30 minutes, and anneal at 165°C for 15 minutes. Figure 5 As shown in FIG, after heat treatment, the contact angle of the master mold surface is about 116°.

[0060] In this embodiment, a trichloro(1H,1H,2H,2H-perfluorooctyl)silane monolayer is self-assembled on the aluminum surface of a planar reflection grating master mold by vapor deposition, and heat treatment is performed to cause the long-chain perfluoroalkyl group (-CF3(CF2)5) to migrate to the outer surface, causing the fluorine element to accumulate on the outer surface, thereby obtaining a modified surface.

[0061] Each step of the surface modification in this embodiment was tested, and the test results were as follows:

[0062] In this embodiment, Figure 2 The contact angle of the aluminum surface after cleaning with acetone, ethanol, and deionized water is about 74°.

[0063] Figure 3 The contact angle of the aluminum surface after UV ozone treatment is about 5°, which is about 69° lower than the angle measured after cleaning with acetone, ethanol and deionized water. This indicates that the number of surface hydroxyl groups has increased, providing reaction sites for the subsequent self-assembly of perfluorooctyltrichlorosilane monolayer film.

[0064] Figure 4 After a monolayer of trichloro(1H,1H,2H,2H-perfluorooctyl)silane was assembled on an aluminum surface, the measured contact angle was approximately 106°. This increase of approximately 100° compared to the UV-ozone treatment indicates that trichloro(1H,1H,2H,2H-perfluorooctyl)silane has self-assembled onto the aluminum surface, significantly improving the anti-fouling properties and high wettability of the master mold surface, facilitating the separation of the PDMS material from the master mold.

[0065] Figure 5 The contact angle measured on the heat-treated aluminum surface is approximately 116°, an increase of approximately 10° compared to the pre-treatment surface. This increase can be attributed to the migration and microphase separation of long-chain perfluoroalkyl chains (-CF3(CF2)5) at high temperatures. Specifically, the long-chain perfluoroalkyl chains (-CF3(CF2)5) migrate toward the outer surface, causing the fluorine element to accumulate there. This ensures the structural integrity of the PDMS soft mold, improves reusability, and significantly reduces costs.

[0066] Example 3

[0067] The difference between this embodiment and embodiment 1 is that the method for preparing the PDMS triangular nanowire soft template is different, and the remaining steps are the same as those in embodiment 1.

[0068] The method for preparing the PDMS triangular nanowire soft template in this embodiment includes the following steps:

[0069] Step 1: Mix the PDMS base and curing agent in a ratio of 10:1, and place in a -80 kPa vacuum drying oven for 20 minutes to remove bubbles to obtain a prepolymer.

[0070] Step 2: Apply the prepolymer dropwise onto the surface of the treated master template, allowing it to disperse evenly under gravity. Finally, cure the template in a 60°C oven for four hours to create a PDMS spatially confined growth template with a right-angled triangular cross-section.

[0071] Step 3: The prepared PDMS template is cut into 1×1 cm size for the subsequent growth of perovskite nanowire arrays.

[0072] The PDMS triangular nanowire soft template prepared in this example was tested. Figure 6 The SEM top view of the triangular PDMS soft template prepared by the method steps in this embodiment is shown. Figure 7 The following SEM images show the triangular PDMS soft template prepared using the method steps in this example. Both images demonstrate the structural integrity of the surface-modified PDMS soft template, with a smooth surface and sharp edges. The PDMS nearly perfectly replicates the right-angled triangular groove structure of the master mold, making it suitable for subsequent growth of synthetic perovskite nanowire arrays.

[0073] Example 4

[0074] The difference between this embodiment and embodiment 1 lies in the difference in the preparation of the precursor solution and the final preparation of the titanite nanowire array. The remaining steps are the same as those in embodiment 1.

[0075] The preparation of the precursor solution and the final preparation of the titanite nanowire array in this embodiment include the following steps:

[0076] Step 1: Clean a 5 ml sample bottle with ethanol and deionized water respectively, and then place it in a 60 °C oven to dry the water.

[0077] Step 2: Prepare the CsPbBr3 precursor solution. Use a pipette to draw 2 ml of DMSO into a 5 ml sample vial. Weigh 1 mol of PbBr2 into the vial using a balance and stir at 70°C for 5 minutes until the PbBr2 powder is completely dissolved. Then weigh 1 mol of CsBr into the vial and stir at 70°C for 2 hours to completely dissolve the PbBr2 and CsBr. Filter the precursor solution using a 0.22 μm pore filter syringe to remove undissolved impurities, resulting in a clear and transparent precursor solution.

[0078] Step 3: Clean the Si substrate. Place the Si bottom on a polytetrafluoroethylene cleaning rack and ultrasonically clean it in an ethanol solvent for 10 minutes. Then, use deionized water to clean the cleaned Si substrate by spraying and overflowing for 10 minutes. Use acetone solution to ultrasonically clean the cleaned Si bottom for 10 minutes. Then, use deionized water to clean the cleaned Si substrate by spraying and overflowing for 10 minutes, and finally blow dry with nitrogen.

[0079] Step 4: Lay the prepared PDMS soft template on the cleaned Si substrate. Use a pipette to drop the precursor solution onto one side of the triangular channel formed by the two substrates. Capillary action draws the precursor solution into the channel. Finally, place the template on a heating plate and heat at 70°C for 45 minutes to crystallize, producing a perovskite nanowire array with a right-angled triangular microstructure.

[0080] The perovskite nanowire array prepared in this example was tested. Figure 8 shows an SEM image of the perovskite nanowire array prepared by the method in this embodiment; Figure 9 Fluorescence micrographs of the perovskite nanowire array prepared using the method of this example are shown. These two images show that the perovskite nanowire array prepared using the method of this example is regularly arranged with a period of approximately 3.33 μm. Individual nanowires have good morphology, with clear boundaries between adjacent nanowires and a consistent, uniform morphology, forming a right-angled triangle structure.

[0081] Figure 10 The X-ray diffraction (XRD) pattern of CsPbBr3 nanowires, a perovskite nanowire array prepared using the method of this example, on a glass substrate is shown. The pattern shows distinct double diffraction peaks at 15.2° and 30.7°. Comparison with a standard PDF card also confirms that the prepared nanowires are CsPbBr3.

[0082] Figure 10 The PL emission peak diagram of the CsPbBr3 nanowires of the perovskite nanowire array prepared by the method in this embodiment is shown. It can be seen from the figure that a PL emission peak of about 530 nm and a half-peak width of about 20.6 nm are presented, showing a high color purity.

[0083] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a right-angled triangle all-inorganic perovskite nanowire array, characterized in that: The preparation method comprises: S100, modifying the surface of the planar reflection grating, and using the modified planar reflection grating as a master mold, The surface structure of the planar reflection grating is a right-angled triangle structure; S200, mixing the PDMS main agent and the curing agent to prepare a prepolymer, The prepolymer is drop-coated on the surface of the master mold to disperse naturally, and after curing, a PDMS spatial confined growth template with a right-angled triangle cross-section is prepared. cutting the PDMS spatially confined growth template to obtain a PDMS soft template; S300, adding PbBr2 to the DMSO liquid and stirring until the PbBr2 powder is completely dissolved to prepare a first mixed solution, adding CsBr to the first mixed solution and stirring until the CsBr powder is completely dissolved to prepare a second mixed solution, Filtering the two mixed solutions using a filter membrane syringe to remove undissolved impurities to prepare a precursor solution; S400, cleaning the target substrate, and after cleaning, laminating the PDMS soft template to the target substrate. The precursor solution is dropped onto one side of the triangular channel formed after the PDMS soft template and the target substrate are bonded together, and the perovskite precursor solution is sucked into the triangular channel by capillary action, and then heated and crystallized. After crystallization is completed, the PDMS soft template is removed to prepare the perovskite nanowire array.

2. The method for preparing a right-angled triangle all-inorganic perovskite nanowire array according to claim 1, characterized in that: The stirring temperature of the first mixed solution and the second mixed solution is 60-70°C.

3. The method for preparing a right-angled triangle all-inorganic perovskite nanowire array according to claim 1, characterized in that: The surface material of the plane reflection grating is aluminum. By modifying the surface of the plane reflection grating, the separation smoothness of the master mold and PDMS and the reusability of the master mold are improved. The surface modification of the planar reflection grating is achieved by self-assembling a layer of perfluorooctyltrichlorosilane film on the aluminum surface of the planar reflection grating.

4. The method for preparing a right-angled triangle all-inorganic perovskite nanowire array according to claim 3, characterized in that: The surface modification of the planar reflection grating comprises the following sub-steps: S110, placing the plane reflection grating on a polytetrafluoroethylene cleaning rack, placing it in an ethanol solvent and performing a first cleaning with ultrasonic waves, After the first cleaning is completed, the plane reflection grating is cleaned for the second time using deionized water by spraying and overflowing. After the second cleaning is completed, the plane reflection grating is cleaned for the third time using an acetone solution and ultrasonic cleaning. Finally, the plane reflection grating is cleaned for the fourth time using deionized water by spraying and overflowing; S120, using UV-ozone treatment to clean the planar reflection grating to increase the number of surface hydroxyl groups of the planar reflection grating; S130, placing perfluorooctyltrichlorosilane and a plane reflection grating in a vacuum drying oven, and self-assembling a perfluorooctyltrichlorosilane monolayer film on the surface of the plane reflection grating by vapor deposition; S140. After the self-assembly of the perfluorooctyltrichlorosilane monolayer film is completed, the plane reflection grating is placed in a muffle furnace for heat treatment.

5. The method for preparing a right-angled triangle all-inorganic perovskite nanowire array according to claim 1, characterized in that: The step S200 includes the following sub-steps: S210, mixing the PDMS main agent and the curing agent in a mass ratio of 10:1, and allowing the mixture to stand in a vacuum drying oven to remove bubbles, thereby obtaining a prepolymer; S220, drop the prepolymer onto the surface of the master mold and disperse it evenly under the action of gravity. The PDMS spatial confined growth template with a right-angled triangle cross-section was prepared by mirror curing in a constant temperature oven at 60°C for 4 hours. S230, cutting the PDMS spatial confinement growth template into a size of 1×1 cm for the growth of perovskite nanowire arrays.

6. The method for preparing a right-angled triangle all-inorganic perovskite nanowire array according to claim 1, characterized in that: The target substrate in step S400 is a Si substrate.

7. The method for preparing a right-angled triangle all-inorganic perovskite nanowire array according to claim 1, characterized in that: The temperature of the crystallization reaction in step S400 is 70° C., and the reaction time is 45 minutes.

8. The method for preparing a right-angled triangle all-inorganic perovskite nanowire array according to claim 1, characterized in that: The cleaning target substrate comprises: The target substrate was placed on a polytetrafluoroethylene cleaning rack and ultrasonically cleaned in ethanol solvent for 10 minutes; Then, the cleaned Si substrate was cleaned with deionized water by spraying and overflowing for 10 minutes; The cleaned Si substrate was then ultrasonically cleaned with acetone solution for 10 minutes; Finally, the cleaned Si substrate was cleaned with deionized water by spraying and overflowing for 10 minutes, and nitrogen was used to blow dry the target substrate after cleaning.

9. A right-angled triangle all-inorganic perovskite nanowire array, characterized in that: The all-inorganic perovskite nanowire array is prepared according to the preparation method according to any one of claims 1 to 8.

10. An application of a right-angled triangle all-inorganic perovskite nanowire array, characterized in that: The perovskite nanowire array is prepared according to the preparation method according to any one of claims 1 to 8, Applications include: (1) Application in the preparation of flexible perovskite solar cells; (2) Application in the preparation of high current yield perovskite solar cells; (3) Application in the preparation of high-active-area perovskite solar cells.

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