Quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation and preparation method thereof

Abstract

The application discloses a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation and a preparation method thereof, and belongs to the field of luminescent materials and nanotechnology. The preparation method of the quasi-two-dimensional perovskite light-emitting film comprises the following steps: dissolving macromolecular cationic organic matter, monovalent cation halide and divalent cation halide in a polar organic solvent to obtain a precursor solution; and placing the precursor solution in an environment containing a special atmosphere to perform two-stage spin coating to obtain the quasi-two-dimensional perovskite light-emitting film. The special atmosphere is an atmosphere formed by volatilization of one or more of dimethyl sulfoxide, N-N dimethylformamide, isopropyl alcohol, ethyl acetate, chlorobenzene and toluene. According to the application, the composition ratio of the atmosphere environment can be regulated to realize light emission in the range of 380 nm-800 nm visible light-near infrared, and the quasi-two-dimensional perovskite film with excellent light-emitting performance, high environmental stability and high phase purity can be rapidly obtained without annealing and anti-solvent treatment.

Description

Technical Field

[0001] The present invention relates to the fields of luminescent materials and nanotechnology, and in particular to a quasi-two-dimensional perovskite luminescent film based on atmosphere regulation and a preparation method thereof. Background Art

[0002] In recent years, metal halide perovskite materials have attracted more and more researchers' attention as an excellent photovoltaic and luminescent material due to their advantages such as adjustable band gap, strong absorption capacity, high gain coefficient, and high photoluminescence quantum yield. Compared with three-dimensional perovskite materials, quasi-two-dimensional perovskite materials are made of long-chain molecular groups such as long-chain organic hydrophobic cations, such as naphthylamine (NMA). + ), phenylethylamine (PEA + ) separates the perovskite layers, forming a quantum confinement effect. At the same time, its quantum confinement effect does not depend on the macroscopic size or thickness of the material, but more on the microscopic thickness of the perovskite in each layer. This thickness is often replaced by the n value. When the n value approaches infinity, it is considered a three-dimensional material (Ma S, Cai M, Cheng T, et al. Sci China Mater, 2018, 61 (10): 1257.). Therefore, quasi-two-dimensional perovskites have stronger environmental stability and self-assembled multi-quantum well structure. They can obtain adjustable band gaps and large exciton binding energy by inducing dielectric and quantum confinement effects. At the same time, due to the rapid energy transfer mechanism between different n values, they can guide them to achieve high photoluminescence efficiency (Zhang L, Sun C, He T, et al. Light: Science & Applications, 2021, 10 (1): 61.), and have broader application prospects in light-emitting devices.

[0003] Quasi-two-dimensional perovskite films can achieve full-band luminescence by designing bandgap structures. They have extremely narrow bandwidths and extremely high photoluminescence efficiency. Therefore, their excellent optoelectronic properties have led to their widespread application in display, lighting, laser lighting, photodetection, and solar cells. The Institute of Semiconductors, Chinese Academy of Sciences, has disclosed a method for using two-dimensional perovskites to replace traditional organic hole transport layers to improve hole transport performance, effectively increase the brightness of light-emitting diodes, and achieve better carrier injection balance (application number: CN202211697423.4). South China University of Technology has published a tri(4-morpholino)phosphine oxide-doped quasi-two-dimensional perovskite film and its preparation method, resulting in a dense, pinhole-free, low-defect density, high-quality quasi-two-dimensional perovskite film; the luminous efficiency and luminous intensity of the prepared light-emitting device have been significantly improved. (Application number: CN202210920388.1).

[0004] Usually, when preparing quasi-two-dimensional perovskite films, it is difficult to directly obtain pure phase (i.e., uniform n value) quasi-two-dimensional perovskite films, but rather a mixture of multiple phases with different n values. The coexistence of different phases will lead to multiple energy transfer paths, which ultimately results in the generated light being multi-color broadband luminescence, limiting the effective application of quasi-two-dimensional perovskite films in the fields of lasers and monochromatic light sources. In the preparation process of quasi-two-dimensional perovskite films, in order to improve the phase purity, annealing or anti-solvent treatment is often used to assist nucleation growth, but at the same time, too many variables are introduced, such as annealing temperature, annealing time, and anti-solvent addition time, which are difficult to accurately control. The process is very complicated, making it difficult to obtain a uniform and dense film. In addition, since quasi-two-dimensional perovskites are sensitive to water and oxygen, they are easily decomposed and inactivated. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] A method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation comprises the following steps:

[0008] dissolving a macromolecular cationic organic compound, a monovalent cationic halide, and a divalent cationic halide in a polar organic solvent to obtain a precursor solution;

[0009] Placing the precursor solution in an environment containing a special atmosphere and performing two-stage spin coating to obtain the quasi-two-dimensional perovskite light-emitting film;

[0010] The special atmosphere is an atmosphere formed by volatilization of one or more of dimethyl sulfoxide, N-dimethylformamide, isopropyl alcohol, ethyl acetate, chlorobenzene, and toluene.

[0011] Preferably, the step of dissolving the macromolecular cationic organic compound, the monovalent cationic halide, and the divalent cationic halide in a polar organic solvent to obtain a precursor solution specifically includes:

[0012] adding a macromolecular cationic organic compound, a monovalent cationic halide, and a divalent cationic halide to a polar organic solvent to obtain a mixed solution;

[0013] The mixed solution is magnetically stirred at a temperature of 25-100° C. and then filtered to obtain a precursor solution.

[0014] Preferably, the macromolecular cationic organic compound is one or more of naphthylamine cationic organic compounds, phenylethylamine cationic organic compounds, n-butylamine cationic organic compounds, phenylbutylamine cationic organic compounds and triethylamine cationic organic compounds.

[0015] Preferably, the monovalent cation halide is a halide of one or more of potassium, cesium, rubidium, methylamine and formamidine.

[0016] Preferably, the divalent cation halide is a halide of one or more of lead, chromium, tin and germanium.

[0017] Preferably, the polar organic solvent includes at least one of dimethyl sulfoxide, N-dimethylformamide, γ-hydroxybutyrolactone, N-methylpyrrolidone and ethylene glycol methyl ether.

[0018] Preferably, the pressure of the tailor-made atmosphere is 0.5-3000 Pa.

[0019] Preferably, the two-stage spin coating method is as follows: in the special atmosphere environment, the precursor solution is spin-coated on the substrate at a rotation speed of 200-1000 rpm for 2-10 seconds, and then the rotation speed is increased to 2000-8000 rpm, and the second stage spin coating is performed for 20-90 seconds to form a quasi-two-dimensional perovskite film with a light emission wavelength of 380nm-800nm.

[0020] Another object of an embodiment of the present invention is to provide a quasi-two-dimensional perovskite light-emitting film prepared by the above-mentioned preparation method.

[0021] The preparation method of the quasi-two-dimensional perovskite luminescent film based on atmosphere regulation provided in an embodiment of the present invention is based on an organic-inorganic hybrid halide perovskite precursor solution. By adjusting the ambient atmosphere during spin coating, adjustable luminescence in the visible band of 380nm-800nm ​​is achieved. No additional annealing and anti-solvent treatment are required during the spin coating process, and a quasi-two-dimensional perovskite film with excellent luminescence performance, high environmental stability and high phase purity can be quickly obtained, which is of great significance for realizing laser emission and high-color purity display and lighting.

[0022] This preparation method has simple process, good controllability, and stable batch performance, which is conducive to the batch production of high-performance lasers. It is economical, convenient, and has good repeatability. The prepared quasi-two-dimensional perovskite film is uniform and dense, with low roughness, excellent luminescence performance, good environmental stability, high phase purity, low laser threshold, and high quality factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Diagram of the formation process of quasi-two-dimensional perovskite film;

[0024] Figure 2This is the photoluminescence spectrum of the quasi-two-dimensional perovskite film prepared in Example 1 of the present invention;

[0025] Figure 3 This is a scanning electron microscope image of the quasi-two-dimensional perovskite film prepared in Example 2 of the present invention;

[0026] Figure 4 This is the laser emission spectrum of the quasi-two-dimensional perovskite film prepared in Example 2 of the present invention;

[0027] Figure 5 This is a graph showing the variation of the lasing intensity and full width at half maximum (FWHM) of the quasi-two-dimensional perovskite film prepared in Example 5 of the present invention with the pump flux. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] like Figure 1 As shown, in one embodiment of the present invention, a method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation is provided, which includes the following steps:

[0030] S1, dissolving a macromolecular cationic organic compound (AX), a monovalent cationic halide (A'X), and a divalent cationic halide (BX2) in a polar organic solvent to obtain a precursor solution (A-A'BX);

[0031] S2, placing the precursor solution in an environment containing a special atmosphere and performing two-stage spin coating to obtain the quasi-two-dimensional perovskite light-emitting film;

[0032] The special atmosphere is an atmosphere formed by volatilization of one or more of dimethyl sulfoxide (DMSO), N-dimethylformamide (DMF), isopropyl alcohol (IPA), ethyl acetate (EA), chlorobenzene (CB), and toluene (TL).

[0033] In a preferred embodiment of the present invention, the step of dissolving the macromolecular cationic organic compound, the monovalent cationic halide, and the divalent cationic halide in a polar organic solvent to obtain a precursor solution specifically includes:

[0034] S11, adding a macromolecular cationic organic compound AX, a monovalent cationic halide A'X, and a divalent cationic halide BX2 to a polar organic solvent to obtain a mixed solution;

[0035] S12. The mixed solution is magnetically stirred at a temperature of 25-100° C., and then filtered to obtain a precursor solution.

[0036] Specifically, the rotation speed of the magnetic stirring can be controlled at 200-5000 rpm, and the stirring time can be controlled at 0.5-12 h; the above-mentioned filtration step can be performed using a 0.22 μm or 0.45 μm nylon NY membrane disposable oil filter.

[0037] In addition, the composition of the quasi-two-dimensional perovskite light-emitting film is A2-A' n-1 B n X 3n+1 , where n represents the thickness of the perovskite layer between the organic layers; wherein the macromolecular cationic organic compound AX, the monovalent cationic halide A'X, and the divalent cationic halide BX2 can be dissolved in a polar organic solvent in any proportion at a molar ratio of 0.1:0.1:1-1.7:1.7:1 to form B 2+ The precursor solution A-A'BX has an ion concentration of 0.02-1.0 M molar concentration.

[0038] In a preferred embodiment of the present invention, the macromolecular cationic organic compound AX is one or more of a naphthylamine cationic organic compound (NMAX), a phenylethylamine cationic organic compound (PEAX), a n-butylamine cationic organic compound (BAX), a phenylbutylamine cationic organic compound (PBAX), and a triethylamine cationic organic compound (TEAX); the monovalent cationic halide A'X is a halide of one or more of potassium (K), cesium (Cs), rubidium (Rb), methylamine (MA), and formamidine (FA), that is, A' is one or more of K, Cs, Rb, MA, and FA; the divalent cationic halide BX2 is a halide of one or more of lead (Pb), chromium (Cr), tin (Sn), and germanium (Ge). It should be noted that the X mentioned above refers to a halogen element, specifically a mixture of one or more of Cl, Br, and I.

[0039] In a preferred embodiment of the present invention, the polar organic solvent includes at least one of dimethyl sulfoxide (DMSO), N-dimethylformamide (DMF), γ-hydroxybutyrolactone (GBL), N-methylpyrrolidone (NMP) and ethylene glycol monomethyl ether (MOE).

[0040] In a preferred embodiment of the present invention, the pressure of the tailor-made atmosphere is 0.5-3000 Pa.

[0041] In a preferred embodiment of the present invention, the two-stage spin coating method is as follows: in the aforementioned special atmosphere, a certain amount of precursor solution is spin-coated on the substrate at a speed of 200-1000 rpm for 2-10 seconds, and then the speed is increased to 2000-8000 rpm and the second stage spin coating is performed for 20-90 seconds to form a luminescent material with a wavelength of 380nm-800nm ​​and a composition of A2-A' n-1 B n X 3n+1 Quasi-two-dimensional perovskite films.

[0042] The embodiments of the present invention use an atmosphere regulation method to control the nucleation and growth process of metal halide quasi-two-dimensional perovskite films, and can obtain uniform and dense quasi-two-dimensional perovskite films without annealing or antisolvent treatment. This allows for simple and controllable regulation of the perovskite band gap. Compared with quasi-two-dimensional perovskites prepared using traditional antisolvent inert environment methods, the perovskite band gap can be easily and controllably adjusted. The perovskite band gap is more widely regulated, with improved stability, denser and more uniform film morphology, narrower luminescence half-width, and superior optical properties. Furthermore, the film exhibits a low laser threshold and a high quality factor. This method can be used to manufacture quasi-two-dimensional perovskite thin-film lasers with high photoluminescence quantum yield and high stability, or for high-color-purity displays and lighting.

[0043] The following embodiments are some specific implementation cases and experimental cases in practical applications of the present invention, but are not limited thereto.

[0044] Example 1: This example provides a method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation, which includes the following steps:

[0045] (1) PbX2 with a molar concentration of 0.2 M and appropriate proportions of NMAX and FAX were dissolved in a mixed solution of NMP and DMF in a certain proportion;

[0046] (2) The mixed solution was placed on a magnetic stirrer at 800 rpm at 45°C for 8 h, and then filtered through a 0.45 μm nylon NY membrane disposable oil filter to obtain a (NMA)-(FA)PbX perovskite precursor solution for later use;

[0047] (3) Enter the appropriate atmospheric pressure according to Table 1 below, and adjust the atmospheric composition according to the halogen ions and target wavelength;

[0048] (4) In the aforementioned atmosphere, a certain amount of precursor solution was initially spin-coated on the substrate at a speed of 500 rpm for 5 seconds, and then the speed was increased to 3000 rpm and a second spin-coating was performed for 30 seconds to finally obtain a composition of (NM A)2(FA) n-1 Pb n X 3n+1quasi-two-dimensional perovskite films, where n represents the thickness of the perovskite layer between the organic layers, and X is a mixture of one or more of Cl, Br, and I. The performance test results of the quasi-two-dimensional perovskite films obtained under different process control are shown in Table 1.

[0049] Table 1

[0050]

[0051] The quasi-two-dimensional perovskite film prepared in the above embodiment achieves adjustable wavelength emission in the range of 445nm-723nm, with a PLQY of up to 99%, a half-peak width of the excited laser of 0.17nm, and a lasing threshold of 3.7μJ / cm 2 , and its photoluminescence spectrum is as follows Figure 2 shown.

[0052] Example 2: This example provides a method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation, which comprises the following steps:

[0053] (1) PbX2 with a molar concentration of 0.4 M and appropriate proportions of PEAX and CsX were dissolved in a mixed solution of DMSO and DMF at a certain ratio;

[0054] (2) The mixed solution was placed on a magnetic stirrer at 90°C and a speed of 1500 rpm for 2 h, and then filtered through a 0.22 μm nylon NY membrane disposable oil filter to obtain a (PEA)-Cs PbX perovskite precursor solution for later use;

[0055] (3) Enter the appropriate atmospheric pressure according to Table 2 below, and adjust the atmospheric composition according to the halogen ions and target wavelength;

[0056] (4) In the aforementioned atmosphere, a certain amount of precursor solution was initially spin-coated on the substrate at a speed of 500 rpm for 5 seconds, and then the speed was increased to 4500 rpm and a second spin-coating was performed for 25 seconds to finally obtain a composition of (PEA)2Cs n-1 Pb n X 3n+1 quasi-two-dimensional perovskite films, where n represents the thickness of the perovskite layer between the organic layers, and X is a mixture of one or more of Cl, Br, and I. The performance test results of the quasi-two-dimensional perovskite films obtained under different process control are shown in Table 2.

[0057] Table 2

[0058]

[0059] The quasi-two-dimensional perovskite film prepared in the above embodiment achieves adjustable wavelength emission in the range of 382nm-659nm, with a PLQY of up to 96%, a half-peak width of the excited laser of 0.15nm, and a lasing threshold of 4.7μJ / cm 2 , and its scanning electron microscope image and laser emission spectrum are shown as follows: Figure 3 and Figure 4 shown.

[0060] Example 3: This example provides a method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation, which comprises the following steps:

[0061] (1) Dissolve 0.6 M molar concentration of PbX2 and appropriate proportions of BAX and MAX in a mixed solution of MOE and DMF;

[0062] (2) The mixed solution was placed on a magnetic stirrer at 800 rpm at 60°C for 6 h, and then filtered through a 0.22 μm nylon NY membrane disposable oil filter to obtain a (BA)-(MA)PbX perovskite precursor solution for later use;

[0063] (3) Enter the appropriate atmospheric pressure according to Table 3 below, and adjust the atmospheric composition according to the halogen ions and target wavelength;

[0064] (4) In the aforementioned atmosphere, a certain amount of precursor solution was initially spin-coated on the substrate at a speed of 500 rpm for 5 seconds, and then the speed was increased to 2800 rpm and a second spin-coating was performed for 40 seconds to finally obtain a composition of (BA)2(MA) n-1 Pb n X 3n+1 quasi-two-dimensional perovskite films, where n represents the thickness of the perovskite layer between the organic layers, and X is a mixture of one or more of Cl, Br, and I. The performance test results of the quasi-two-dimensional perovskite films obtained under different process control are shown in Table 3.

[0065]

[0066]

[0067] The quasi-two-dimensional perovskite film prepared in the above embodiment achieves adjustable wavelength emission in the range of 392nm-690nm, with a PLQY of up to 95%, a half-peak width of the excited laser of 0.13nm, and a lasing threshold of 2.6μJ / cm 2 .

[0068] Example 4: This example provides a method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation, which comprises the following steps:

[0069] (1) Dissolve 0.18 M molar concentration of SnX2 and appropriate proportions of PBAX and FAX in a mixed solution of DMSO and DMF;

[0070] (2) The mixed solution was placed on a magnetic stirrer at 75°C and a speed of 1800 rpm for 4 h, and then filtered through a 0.22 μm nylon NY membrane disposable oil filter to obtain a (PBA)-(FA)SnX perovskite precursor solution for later use;

[0071] (3) Enter the appropriate atmospheric pressure according to Table 4 below, and adjust the atmospheric composition according to the halogen ions and target wavelength;

[0072] (4) In the aforementioned atmosphere, a certain amount of precursor solution was initially spin-coated on the substrate at a speed of 500 rpm for 5 seconds, and then the speed was increased to 5000 rpm and a second spin-coating was performed for 15 seconds to finally obtain a composition of (PBA)2(FA) n-1 Sn n X 3n+1 quasi-two-dimensional perovskite films, where n represents the thickness of the perovskite layer between the organic layers, and X is a mixture of one or more of Cl, Br, and I. The performance test results of the quasi-two-dimensional perovskite films obtained under different process control are shown in Table 4.

[0073] Table 4

[0074]

[0075] The quasi-two-dimensional perovskite film prepared in the above embodiment achieves adjustable wavelength emission in the range of 406nm-763nm, with a PLQY of up to 98%, a half-peak width of the excited laser of 0.11nm, and a lasing threshold of 3.2μJ / cm 2 .

[0076] Example 5: This example provides a method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation, which comprises the following steps:

[0077] (1) Dissolve 0.3 M molar concentration of SnX2 and appropriate proportions of TEAX and MAX in a mixed solution of GBL and DMF in a certain proportion;

[0078] (2) The mixed solution was placed on a magnetic stirrer at 1000 rpm at 25°C for 12 h, and then filtered through a 0.45 μm nylon NY membrane disposable oil filter to obtain a (TEA)-(MA)SnX perovskite precursor solution for later use;

[0079] (3) Enter the appropriate atmospheric pressure according to Table 5 below, and adjust the atmospheric composition according to the halogen ions and target wavelength;

[0080] (4) In the aforementioned atmosphere, a certain amount of precursor solution was initially spin-coated on the substrate at a speed of 800 rpm for 5 seconds, and then the speed was increased to 2000 rpm and a second spin-coating was performed for 50 seconds to finally obtain a composition of (TEA)2(MA) n-1 Sn n X 3n+1 quasi-two-dimensional perovskite films, where n represents the thickness of the perovskite layer between the organic layers, and X is a mixture of one or more of Cl, Br, and I. The performance test results of the quasi-two-dimensional perovskite films obtained under different process control are shown in Table 5.

[0081] Table 5

[0082]

[0083] The quasi-two-dimensional perovskite film prepared in the above embodiment achieves adjustable wavelength emission in the range of 410nm-796nm, with a PLQY of up to 97%, a half-peak width of the excited laser of 0.19nm, and a lasing threshold of 29μJ / cm 2 The variation of the lasing intensity and full width at half maximum (FWHM) with the pump flux is shown in the figure below: Figure 5 shown.

[0084] Based on the above-mentioned ideal embodiment of the present invention, and through the above description, relevant personnel can make various changes and modifications without departing from the scope of the technical concept of the present invention. The technical scope of the present invention is not limited to the contents of the specification.

Claims

1. A method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere regulation, characterized in that: The following steps are involved: dissolving a macromolecular cationic organic compound, a monovalent cationic halide, and a divalent cationic halide in a polar organic solvent to obtain a precursor solution; Placing the precursor solution in an environment containing a special atmosphere and performing two-stage spin coating to obtain the quasi-two-dimensional perovskite light-emitting film; The special atmosphere is an atmosphere formed by volatilization of one or more of dimethyl sulfoxide, N-dimethylformamide, isopropyl alcohol, ethyl acetate, chlorobenzene, and toluene.

2. The method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere control according to claim 1, characterized in that: The step of dissolving a macromolecular cationic organic compound, a monovalent cationic halide, and a divalent cationic halide in a polar organic solvent to obtain a precursor solution specifically comprises: adding a macromolecular cationic organic compound, a monovalent cationic halide, and a divalent cationic halide to a polar organic solvent to obtain a mixed solution; The mixed solution is magnetically stirred at a temperature of 25-100° C. and then filtered to obtain a precursor solution.

3. The method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere control according to claim 1 or 2, characterized in that: The macromolecular cationic organic matter is one or more of naphthylamine cationic organic matter, phenylethylamine cationic organic matter, n-butylamine cationic organic matter, phenylbutylamine cationic organic matter and triethylamine cationic organic matter.

4. The method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere control according to claim 1 or 2, characterized in that: The monovalent cation halide is one or more halides of potassium, cesium, rubidium, methylamine and formamidine.

5. The method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere control according to claim 1 or 2, characterized in that: The divalent cation halide is a halide of one or more of lead, chromium, tin and germanium.

6. The method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere control according to claim 1 or 2, characterized in that: The polar organic solvent includes at least one of dimethyl sulfoxide, N-dimethylformamide, γ-hydroxybutyrolactone, N-methylpyrrolidone and ethylene glycol methyl ether.

7. The method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere control according to claim 1 or 2, characterized in that: The pressure of the specially prepared atmosphere is 0.5-3000 Pa.

8. The method for preparing a quasi-two-dimensional perovskite light-emitting film based on atmosphere control according to claim 1, characterized in that: The two-stage spin coating method is as follows: in the special atmosphere environment, the precursor solution is spin-coated on the substrate at a rotation speed of 200-1000 rpm for 2-10 seconds, and then the rotation speed is increased to 2000-8000 rpm, and the second stage spin coating is performed for 20-90 seconds to form a quasi-two-dimensional perovskite film with a light emission wavelength of 380nm-800nm.

9. A quasi-two-dimensional perovskite luminescent film prepared by the preparation method according to any one of claims 1 to 8.

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