Preparation method of one-dimensional cesium-lead-bromine nanowire film, film material, element and equipment

Abstract

The invention discloses a preparation method of a one-dimensional cesium-lead-bromine nanowire film, a film material, an element and equipment. The preparation method comprises the following steps: preparing a first solution containing a proper amount of acetone, toluene and a surfactant; weighing lead bromide and cesium bromide in a molar ratio of 1: 1, and grinding into uniform powder; in a constant-temperature water bath, adding the powder into the first solution, and stirring for reaction; after the reaction is finished, separating and washing to obtain a pure cesium-lead-bromine nanowire; dispersing the cesium-lead-bromine nanowires in a mixed solvent of normal octane and normal hexane to obtain a nanowire dispersion liquid required for preparing the thin film; and coating the nanowire dispersion liquid on a substrate, and drying at room temperature to obtain the uniform one-dimensional cesium-lead-bromine nanowire film with high polarization luminescence and polarization response. According to the invention, the preparation process of the one-dimensional cesium-lead-bromine nanowire film is optimized, and the preparation of the macroscopic orientation cesium-lead-bromine nanowire film with high polarization luminescence and polarization response is realized, so that the preparation of an optical device with good anisotropy and polarization performance is realized.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, specifically relating to a method for preparing one-dimensional cesium lead bromine nanowire thin films, as well as film materials, components, and equipment. Background Technology

[0002] Cesium lead bromide perovskite is a semiconductor material with excellent optoelectronic properties and great application potential. Its high light absorption coefficient and other advantages make it suitable for applications such as solar cells, light-emitting diodes, photodetectors, and sensors. Compared to bulk materials, its nanomaterials exhibit unique nanomaterial properties due to their nanoscale particle size, such as surface and interface effects and small-size effects. The morphology and size of its nanocrystals have gradually been controlled.

[0003] Compared to three-dimensional, two-dimensional, and zero-dimensional cesium lead-bromine nanomaterials, one-dimensional cesium lead-bromine nanomaterials possess superior intrinsic linearly polarized luminescence properties due to their one-dimensional structure and excellent aspect ratio. However, their fabrication methods are subject to many limitations, making it difficult to fabricate nanowires with excellent aspect ratios on a large scale. Regarding nanowire thin films, high-performance perovskite nanowire arrays have been reported using the anodic aluminum oxide template method; however, research on achieving uniformly oriented and highly uniform perovskite nanowire thin films using traditional film-forming processes is scarce.

[0004] Therefore, in order to address the above-mentioned technical problems, it is necessary to provide a method for preparing one-dimensional cesium lead bromine nanowire thin films, as well as film materials, components, and equipment. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing one-dimensional cesium lead bromine nanowire thin films, as well as film materials, components, and equipment.

[0006] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution:

[0007] A method for preparing a one-dimensional cesium lead-bromine nanowire thin film includes: preparing a first solution comprising appropriate amounts of acetone, toluene, and a surfactant; weighing lead bromide and cesium bromide in a 1:1 molar ratio and grinding them into uniform powders; adding the powder to the first solution and stirring the reaction in a constant-temperature water bath; separating and washing the nanowires after the reaction to obtain pure cesium lead-bromine nanowires; dispersing the nanowires in a mixed solvent of n-octane and n-hexane to obtain the nanowire dispersion required for film preparation; coating the nanowire dispersion onto a substrate and drying at room temperature to obtain a uniform one-dimensional cesium lead-bromine nanowire thin film with high polarization luminescence and polarization response. In this method, the equimolar mixing of lead bromide and cesium bromide ensures sufficient combination of cesium ions with lead and bromide ions during the reaction, avoiding a decrease in product purity or structural defects due to imbalance in the raw material ratio. The grinding process increases the contact area of ​​the raw materials, accelerates the reaction rate, and ensures reaction uniformity.

[0008] In one or more embodiments of the present invention, the concentration of the nanowire dispersion is 0.05-0.2 g / mL.

[0009] In one or more embodiments of the present invention, the volume ratio of n-octane to n-hexane in the mixed solvent is (0.66-6):1.

[0010] In one or more embodiments of the present invention, the coating thickness of the nanowire dispersion on the substrate is 50-500 μm.

[0011] In one or more embodiments of the present invention, the surfactant in the first solution is selected from oleic acid and oleylamine.

[0012] In one or more embodiments of the present invention, the surfactant in the first solution comprises oleic acid and oleylamine in a volume ratio of (1-2):1.

[0013] In one or more embodiments of the present invention, the first solution comprises: 0-200 mL acetone, 0-200 mL toluene, 10-20 mL oleic acid, and 10-20 mL oleylamine. In this scheme, the solvent and surfactant work synergistically, ensuring sufficient dissolution of the reactants and regulating the growth direction of the nanowires through the coordination effect of the surfactant, thus inhibiting particle aggregation and laying the foundation for preparing nanowires with excellent aspect ratios.

[0014] In one or more embodiments of the present invention, the first solution comprises: 160 mL acetone, 40 mL toluene, 20 mL oleic acid, and 10 mL oleylamine. The synergistic effect of the solvent and surfactant in this solution ensures the complete dissolution of the reactants and, through the coordination effect of the surfactant, regulates the growth direction of the nanowires, inhibiting particle aggregation and laying the foundation for the preparation of nanowires with excellent aspect ratios.

[0015] In one or more embodiments of the present invention, the film material prepared by the aforementioned method for preparing one-dimensional cesium lead bromine nanowire thin films has a uniform macroscopic orientation structure, excellent anisotropy and polarization performance, with a polarization degree of up to 0.53 for polarization emission, a polarization degree of up to 0.41 for polarization response, and a film roughness as low as 58 nm, providing a high-quality material basis for the preparation of high-performance optical components.

[0016] In one or more embodiments of the present invention, the optical element is prepared from the aforementioned film material. The optical fiber element has anisotropy and polarization performance, which can realize efficient polarized light emission and polarization response. It solves the problems of insufficient polarization performance and poor stability of traditional optical elements, and can meet the application requirements of polarized light emission and detection devices.

[0017] In one or more embodiments of the present invention, the optical device includes the aforementioned optical elements. This solution, with its superior polarization performance of optical elements, has broad application prospects in fields such as solar cells, light-emitting diodes, photodetectors, and sensors, and can significantly improve the photoelectric conversion efficiency, luminous stability, and detection sensitivity of the device.

[0018] Compared with existing technologies, the preparation method, film material, components, and equipment of the one-dimensional cesium lead bromine nanowire thin film of this invention optimizes the preparation process of one-dimensional cesium lead bromine nanowire thin films, realizing the preparation of macroscopically oriented cesium lead bromine nanowire thin films with high polarization luminescence and polarization response, thereby realizing the fabrication of optical devices with good anisotropy and polarization performance. Furthermore, the present invention optimizes the preparation process of one-dimensional cesium lead bromine nanowire thin films by employing a room-temperature liquid-phase synthesis method, eliminating the need for stringent conditions such as high temperature and inert gas protection. The process is simple and convenient to operate, and can synthesize one-dimensional cesium lead bromine nanowires with extremely excellent aspect ratios (up to 1000:1) on a large scale, significantly reducing production costs. By controlling the concentration of the nanowire dispersion, the ratio of the binary mixed solvent, and the coating process, the preparation of macroscopically oriented cesium lead bromine nanowire thin films with high polarization luminescence and polarization response is achieved. The films exhibit good uniformity and low roughness, solving the problems of inconsistent nanowire orientation and unstable film performance in traditional film deposition processes. The prepared film material and the optical components made from it have good anisotropy and excellent polarization performance, providing key technical support for the development of polarized light emission and detection devices, and expanding the application scope of cesium lead bromide perovskite materials in the field of semiconductor optoelectronic devices. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a scanning electron microscope image of one-dimensional cesium lead bromine nanowires in one embodiment of the present invention;

[0021] Figure 2 This is a transmission electron microscope image of one-dimensional cesium lead bromine nanowires in one embodiment of the present invention;

[0022] Figure 3 A high-resolution transmission electron microscope image of one-dimensional cesium lead bromine nanowires in one embodiment of the present invention: Fast Fourier Transform (FFT) diffraction pattern;

[0023] Figure 4This is a photoluminescence spectrum (excitation wavelength 365 nm) of a one-dimensional cesium lead bromine nanowire in one embodiment of the present invention;

[0024] Figure 5 This is the ultraviolet absorption spectrum of a one-dimensional cesium lead bromine nanowire in one embodiment of the present invention;

[0025] Figure 6 This is a scanning electron microscope image of the surface of a one-dimensional cesium lead bromine nanowire drop-coated film in one embodiment of the present invention;

[0026] Figure 7 This is a scanning electron microscope image of the surface of a one-dimensional cesium lead bromine nanowire coated film in one embodiment of the present invention;

[0027] Figure 8 This is a scanning electron microscope image of a cross-section of a one-dimensional cesium lead bromine nanowire thin film in one embodiment of the present invention;

[0028] Figure 9 This is a statistical chart showing the polarization performance test results of cesium lead bromine nanowire dispersions coated with thin films of different concentrations in one embodiment of the present invention.

[0029] Figure 10 This is a roughness statistical diagram characterized by atomic force microscopy of cesium lead bromine nanowire dispersions with different binary solvent ratios coated and dried thin films in one embodiment of the present invention.

[0030] Figure 11 This is an atomic microscope three-dimensional morphology image of a cross-section of a one-dimensional cesium lead bromine nanowire thin film in one embodiment of the present invention;

[0031] Figure 12 This is a statistical chart showing the polarization performance of cesium lead bromine nanowire dispersions with different binary solvent ratios coated and dried thin films in one embodiment of the present invention.

[0032] Figure 13 This is a figure-eight diagram showing the polarization luminescence performance test of a cross-section of a one-dimensional cesium lead bromine nanowire thin film in one embodiment of the present invention.

[0033] Figure 14 The figure shows a diagram illustrating the polarization response performance of a one-dimensional cesium lead bromine nanowire thin film cross-section in one embodiment of the present invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments disclosed herein. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0035] Existing hybrid organic-inorganic perovskite semiconductor nanocrystals and all-inorganic cesium lead bromide perovskite semiconductor nanocrystals used in polarization devices are mostly two-dimensional nanosheets and zero-dimensional quantum dots, while one-dimensional perovskite nanowires are difficult to synthesize, have high costs, and poor aspect ratios.

[0036] Currently, the main methods for preparing one-dimensional cesium lead bromine nanowires include hot injection, room-temperature ligand-assisted reprecipitation, and ultrasonication. The hot injection method requires stringent reaction conditions, including inert gas protection and a high-temperature environment, and the synthesized product requires multiple purification steps, thus consuming significant time, energy, and human resources, thereby increasing production costs. The room-temperature ligand-assisted reprecipitation method also suffers from difficulties in controlling product morphology due to its excessively rapid nucleation rate. The ultrasonic method yields nanowires only a few hundred nanometers in size, thus limiting their aspect ratio.

[0037] Currently, there are many reported methods for preparing nanowire-oriented thin films, such as 3D printing and electric field-assisted methods. However, these methods suffer from drawbacks such as complex processes, high equipment requirements, and limitations on material size. In contrast, blade coating, as a traditional film-forming process, is an effective and simple method for preparing macroscopically oriented nanowires. It allows nanowires to align along the shear force direction, resulting in a uniformly oriented single-domain structure. However, the hydrodynamics of solvent drying after blade coating can affect the uniformity of the film, thus impacting its performance.

[0038] Therefore, this invention provides a simple room-temperature liquid-phase synthesis method for preparing all-inorganic perovskite one-dimensional cesium lead bromine nanowires. This method can synthesize one-dimensional cesium lead bromine semiconductor nanowires with excellent aspect ratios on a large scale. By controlling the concentration of the nanowire dispersion and the ratio of the binary solvent (n-octane and n-hexane), macroscopically oriented cesium lead bromine nanowire films with high polarization luminescence and polarization response were successfully prepared. Their excellent anisotropy and superior polarization properties provide technical support for applications in polarized light emission and detection devices.

[0039] Example 1

[0040] The preparation method of the one-dimensional cesium lead bromine nanowire thin film in this embodiment

[0041] (1) Preparation of liquid phase reaction solution: In a constant temperature water bath at 25℃, connect a 500mL three-necked flask to a spherical condenser, add 160mL of acetone and 40mL of toluene to the three-necked flask, and add 20mL of oleic acid and 10mL of oleylamine surfactant. Stir the solution for 15min at a speed of 4000r / min with a magnetic stirrer to ensure that the solution is fully mixed.

[0042] (2) Prepare the required solid reactants: Weigh 2.936 g (8 mmol) of lead bromide and 1.704 g (8 mmol) of cesium bromide and grind them;

[0043] (3) Pour the ground reaction solid powder into a three-necked flask and continue stirring for 4 hours;

[0044] (4) After the reaction is complete, the product is centrifuged at 5000 r / min and washed with toluene 2-3 times to obtain pure cesium lead bromine nanowires;

[0045] (5) The prepared cesium lead bromine nanowires were dispersed at a concentration of 0.1 g / mL in a mixed solvent of n-octane and n-hexane in a ratio of 4:1 to obtain the nanowire dispersion required for the preparation of the film.

[0046] (6) Apply a 0.1 g / mL one-dimensional cesium lead bromine nanowire dispersion using an adjustable applicator with a gap of 100 μm. Dry at room temperature to obtain a uniform one-dimensional cesium lead bromine nanowire film with high polarization luminescence and polarization response.

[0047] Figure 1 This is a scanning electron microscope image of one-dimensional cesium lead bromine nanowires. (Source: [Insert image here]) Figure 1 It can be seen that the one-dimensional cesium lead bromine nanowires are approximately 10 μm in length.

[0048] Figure 2 This is a transmission electron microscope image of one-dimensional cesium lead bromine nanowires. (From...) Figure 2 It can be seen that the diameter of the cesium lead bromine nanowires is approximately 10 nm. Combined with the results of scanning electron microscopy, it can be seen that its aspect ratio is excellent, approximately 1000:1, thus exhibiting excellent polarization properties.

[0049] Figure 3 The inset shows a high-resolution transmission electron microscope image of one-dimensional cesium lead-bromine nanowires and its fast Fourier transform (FFT) diffraction pattern. The FFT diffraction results in the image indicate that the synthesized cesium lead-bromine nanowires exhibit an orthorhombic phase, with the growth direction of the nanowires axially along the 001 direction and radially along the 110 direction.

[0050] Figure 4 This is the photoluminescence spectrum (excitation wavelength 365 nm) of a one-dimensional cesium lead bromine nanowire. The fluorescence emission peak is located at 516 nm.

[0051] Figure 5 The image shows the ultraviolet absorption spectrum of a one-dimensional cesium lead bromine nanowire. The ultraviolet absorption peak is located at 510 nm.

[0052] Figure 6 Scanning electron microscope image of the surface of a one-dimensional cesium lead bromine nanowire drop-coated film. Figure 7 Scanning electron microscope image of the surface of a one-dimensional cesium lead bromine nanowire coated film. Figure 6 Figure 7It can be seen that, compared with drop-coated films, the shear force of blade coating is very effective in controlling the orientation of nanowires, making them into macroscopic structures with consistent orientation.

[0053] Figure 8 This is a scanning electron microscope image of a cross-section of a one-dimensional cesium lead bromine nanowire thin film. The image shows that the film thickness is approximately 6 μm.

[0054] Figure 9 Statistical graph of polarization performance test results for cesium lead bromine nanowire dispersions coated with thin films at different concentrations. The graph shows that the polarization performance is optimal when the coating concentration is 0.1 g / mL, with polarization luminescence and response polarization degrees of 0.43 and 0.38, respectively.

[0055] Figure 10 Atomic force microscopy (AFM) graphs showing the roughness of cesium-lead-bromine nanowire dispersions coated with dried films in different binary solvent ratios. Figure 11 This is an atomic microscopy three-dimensional morphology image of a cross-section of a one-dimensional cesium lead bromine nanowire thin film. Figure 10 It can be seen from the data that the optimal binary solvent ratio is 4:1 (n-octane:n-hexane), which yields the film with the lowest roughness. Figure 11 It can be seen that the roughness of the lowest nanowire film is 58 nm, and the film uniformity is greatly improved.

[0056] Figure 12 Statistical graph of polarization performance test of cesium lead bromine nanowire dispersions coated and dried thin films with different binary solvent ratios. Figure 13 The figure shows the polarization luminescence performance test of a one-dimensional cesium lead bromine nanowire thin film. Figure 14 The image shows a figure-eight diagram illustrating the polarization response performance of a one-dimensional cesium lead-bromine nanowire thin film cross-section. (Source: [Insert figure here]) Figure 12 It can be seen that the polarization performance of the cesium lead-bromine nanowire film is also optimal under the best binary solvent ratio, demonstrating that appropriate binary solvent control can significantly improve the polarization performance of the cesium lead-bromine nanowire film. Figure 13 , Figure 14 Polarization performance tests showed that the polarization luminescence and response polarization degree of the cesium lead bromine nanowire thin film coated with the optimal binary solvent ratio were increased to 0.53 and 0.41, respectively.

[0057] Example 2

[0058] The only difference between this embodiment and Example 1 is that the mixing ratio of n-octane to n-hexane is 0.66:1. Figure 10 As shown, the lowest nanowire film roughness is 80 nm, and the film uniformity is greatly improved. Figure 12 As shown, the polarization luminescence and response polarization degree of the cesium lead bromine nanowire thin film were increased to 0.44 and 0.38, respectively.

[0059] Example 3

[0060] The only difference between this embodiment and Example 1 is that the mixing ratio of n-octane to n-hexane is 6:1. Figure 10 As shown, the lowest nanowire film roughness is 62 nm, and the film uniformity is greatly improved. Figure 12 As shown, the polarization luminescence and response polarization degree of the cesium lead bromine nanowire thin film were increased to 0.47 and 0.38, respectively.

[0061] Example 4

[0062] The only difference between this embodiment and Example 1 is that the concentration of one-dimensional cesium lead bromine nanowires in the nanowire dispersion is 0.05 g / mL. The minimum nanowire film roughness is 62 nm, and the film uniformity is greatly improved. Figure 9 As shown, the polarization luminescence and response polarization degree of the cesium lead bromine nanowire thin film were increased to 0.41 and 0.36, respectively.

[0063] Example 5

[0064] The only difference between this embodiment and Example 1 is that the concentration of one-dimensional cesium lead bromine nanowires in the nanowire dispersion is 0.2 g / mL. The minimum nanowire film roughness is 75 nm, and the film uniformity is greatly improved. Figure 9 As shown, the polarization luminescence and response polarization degree of the cesium lead bromine nanowire thin film were increased to 0.36 and 0.36, respectively.

[0065] Example 6

[0066] The only difference between this embodiment and Example 1 is that the first solution comprises 100 mL acetone, 100 mL toluene, 20 mL oleic acid, and 10 mL oleylamine. The one-dimensional cesium lead-bromine nanowires in this embodiment have a length of approximately 5 μm and a diameter of approximately 30 nm. The lowest nanowire film roughness obtained is 70 nm, and the film uniformity is significantly improved. The polarization emission and response polarization degree of the cesium lead-bromine nanowire film are improved to 0.38 and 0.36, respectively.

[0067] Example 7

[0068] The only difference between this embodiment and Example 1 is that the first solution comprises 160 mL acetone, 40 mL toluene, 10 mL oleic acid, and 20 mL oleylamine. The one-dimensional cesium lead-bromine nanowires in this embodiment have a length of approximately 2 μm and a diameter of approximately 50 nm. The lowest nanowire film roughness obtained is 80 nm, and the film uniformity is significantly improved. The polarization emission and response polarization degree of the cesium lead-bromine nanowire film are improved to 0.37 and 0.36, respectively.

[0069] Comparative Example 1

[0070] The only difference between this comparative example and Example 1 is that the concentration of one-dimensional cesium lead bromine nanowires in the nanowire dispersion is 0.33 g / mL. The minimum nanowire film roughness is 90 nm, and the film uniformity is greatly improved. Figure 9 As shown, the polarization luminescence and response polarization degree of the cesium lead bromine nanowire thin film were increased to 0.36 and 0.32, respectively.

[0071] In summary, through comparative analysis of the above embodiments and comparative examples, it can be seen that in the preparation method of the one-dimensional cesium lead bromine nanowire thin film of the present invention, the composition of the first solution (especially the optimal ratio of 160 mL acetone, 40 mL toluene, 20 mL oleic acid, and 10 mL oleylamine), the concentration of the nanowire dispersion (0.1 g / mL is optimal), the mixing ratio of n-octane and n-hexane (4:1 is optimal), and the coating process parameters have a significant impact on the morphology of the nanowires, the uniformity of the film, and the polarization properties.

[0072] This invention successfully fabricated one-dimensional cesium lead-bromine nanowires with an aspect ratio as high as 1000:1, and macroscopically oriented nanowire films with a roughness as low as 58 nm, a polarization degree of polarization emission as high as 0.53, and a polarization response degree of polarization as high as 0.41, through optimized fabrication processes. These films exhibit excellent anisotropy and superior polarization performance, solving problems in existing technologies such as the difficulty in fabricating one-dimensional cesium lead-bromine nanowires, poor aspect ratio, poor film orientation and uniformity, and insufficient polarization performance. This provides key technical support for the development of polarized light emission and detection devices and expands the application scope of cesium lead-bromine perovskite materials in the field of semiconductor optoelectronic devices.

[0073] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0074] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing one-dimensional cesium lead bromine nanowire thin films, including... Prepare a first solution comprising appropriate amounts of acetone, toluene, and surfactant; weigh lead bromide and cesium bromide in a molar ratio of 1:1 and grind them into a uniform powder; add the powder to the first solution in a constant temperature water bath and stir to react; After the reaction was completed, the purified cesium lead bromine nanowires were obtained by separation and washing. Cesium lead bromine nanowires were dispersed in a mixed solvent of n-octane and n-hexane to obtain the nanowire dispersion required for film preparation. A uniform one-dimensional cesium lead bromine nanowire thin film with high polarization luminescence and polarization response can be obtained by coating the nanowire dispersion onto a substrate and drying it at room temperature.

2. The method for preparing one-dimensional cesium lead bromine nanowire thin films according to claim 1, characterized in that, The concentration of the nanowire dispersion is 0.05-0.2 g / mL.

3. The method for preparing one-dimensional cesium lead bromine nanowire thin films according to claim 1, characterized in that, The volume ratio of n-octane to n-hexane in the mixed solvent is (0.66-6):

1.

4. The method for preparing a one-dimensional cesium lead bromine nanowire thin film according to claim 1, characterized in that, The nanowire dispersion is coated on the substrate with a thickness of 50-500 μm.

5. The method for preparing a one-dimensional cesium lead bromine nanowire thin film according to claim 1, characterized in that, The surfactant in the first solution is selected from oleic acid and oleylamine.

6. The method for preparing a one-dimensional cesium lead bromine nanowire thin film according to claim 5, characterized in that, The surfactant in the first solution includes oleic acid and oleylamine in a volume ratio of (1-2):

1.

7. The method for preparing a one-dimensional cesium lead bromine nanowire thin film according to claim 1, 5, or 6, characterized in that, The first solution comprises: 0-200 mL acetone, 0-200 mL toluene, 10-20 mL oleic acid, and 10-20 mL oleylamine.

8. A membrane material prepared by the method for preparing one-dimensional cesium lead bromine nanowire thin films according to any one of claims 1-7.

9. An optical element prepared from the film material according to claim 8, wherein the optical fiber element has anisotropy and polarization properties.

10. An optical device, comprising the optical element according to claim 9.

Images