CsPbBr3 inorganic perovskite composite material and preparation method thereof

Abstract

The invention relates to a CsPbBr3 inorganic perovskite composite material and a preparation method thereof. The preparation method comprises the following steps: S1, mixing thiocyanate, inorganic lead salt, inorganic cesium salt and a first carrier for reaction to obtain a first mixture; s2, carrying out mixing reaction on inorganic bromine salt and a second carrier to obtain a second mixture; s3, mixing and reacting the first mixture and the second mixture to obtain a head product; and S4, performing high-temperature calcination on the initial product to obtain the CsPbBr3 inorganic perovskite composite material. Compared with the prior art, the method has the advantages that the thiocyanate is introduced in the preparation process, the thiocyanate can be originally converted into lead sulfate to form a protective layer on the surface of CsPbBr3 during high-temperature calcination, the product has good stability, and the method has the advantages of being simple in preparation process and suitable for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular to a CsPbBr3 inorganic perovskite composite material and a preparation method thereof. Background Art

[0002] In recent years, the research on all-inorganic lead halide perovskite fluorescent material CsPbX3 has gradually become a research hotspot of new luminescent materials. However, the methods for synthesizing CsPbX3 mostly rely on organic ligands and solvents. For example, through the hot injection method, under the protection of nitrogen, oleylamine, oleic acid, 1-octadecene are used to react with cesium source, lead source and bromine source under heating conditions, and then an ice-water bath is used to form the product. Finally, the target product CsPbX3 quantum dots are obtained through centrifugal washing (Cen Wanying, Fan Ting, Lv Jiantao, etc. Synthesis and Luminescence Properties of Cesium Lead Bromide Quantum Dots [J]. Chinese Journal of Luminescence, 2017, 38(11): 1457-1460.). However, the presence of organic ligands limits the stability of quantum dots. When they come into contact with moisture, the perovskite structure will rapidly degrade, losing fluorescence activity. Moreover, such methods rely on inert gases and organic solvents, with complex reactions and high costs, which are not conducive to large-scale production. Therefore, a simple and economical preparation method for high-stability inorganic CsPbBr3 perovskite composite materials is needed.

[0003] Patent Publication No. CN117645870A discloses a blue-light perovskite quantum dot solution, a preparation method and an application thereof. The preparation method includes the following steps: providing green-light perovskite quantum dots, and mixing and reacting the green-light perovskite quantum dot solution with triphenylphosphine oxide and methylammonium thiocyanate to obtain a blue-light perovskite quantum dot solution. The organic ligands in perovskite quantum dots are prone to inactivation during long-term storage, reducing the fluorescence efficiency of quantum dots. In addition, the use of organic substances and solvents is not environmentally friendly. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide a CsPbBr3 inorganic perovskite composite material and a preparation method thereof. By introducing thiocyanate ions during the preparation process, and using the fact that thiocyanate ions can be converted into lead sulfate to form a protective layer on the surface of CsPbBr3 during high-temperature calcination, the product has good stability, and has the characteristics of simple preparation process and suitability for large-scale production.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] In one aspect, the present invention provides a preparation method of a CsPbBr3 inorganic perovskite composite material, which is characterized by including the following steps:

[0007] S1. Mix and react a thiocyanate, an inorganic lead salt, an inorganic cesium salt with a first carrier to obtain a first mixture;

[0008] S2. Mix the inorganic bromide salt with the second carrier and react to obtain a second mixture;

[0009] S3. Mix the first mixture and the second mixture and react to obtain a preliminary product;

[0010] S4. Calcinate the preliminary product at high temperature to obtain a CsPbBr3 inorganic perovskite composite material, and the preparation is completed.

[0011] Further, in step S1, the thiocyanate includes potassium thiocyanate (KSCN), sodium thiocyanate (NaSCN), lead thiocyanate (Pb(SCN)2), and aluminum thiocyanate (Al(SCN)3);

[0012] The inorganic lead salt includes lead bromide (PbBr2) and Pb(SCN)2;

[0013] The inorganic cesium salt includes cesium bromide (CsBr) and cesium acetate (CsAc).

[0014] Further, in step S1, the first carrier includes molecular sieve, silica gel, and quartz sand;

[0015] In step S2, the second carrier includes molecular sieve, silica gel, and quartz sand.

[0016] Further, in step S1, the molar ratio of thiocyanate ions in the thiocyanate, lead ions in the inorganic lead salt, cesium ions in the cesium salt, and the first carrier is 0.5 - 2:1:0.5 - 1:1 - 4, preferably 0.5 - 2:1:0.5 - 1:1 - 3.

[0017] Further, in step S2, mix the inorganic bromide salt, the thiocyanate, and the second carrier and react to obtain a second mixture;

[0018] The molar ratio of thiocyanate ions in the thiocyanate to lead ions in the inorganic lead salt in steps S1 and S2 is 0.5 - 2:1.

[0019] Further, in step S2, the inorganic bromide salt includes potassium bromide (KBr), lead bromide (PbBr2), and sodium bromide (NaBr);

[0020] The molar ratio of the inorganic bromide salt to the second carrier is 0.5 - 1:2.

[0021] Further, in step S3, the molar ratio of lead element in the first mixture to bromine element in the second mixture is 0.5 - 1.5:1.

[0022] Further, in steps S1, S2, and S3, the mixing reaction includes ball milling and grinding.

[0023] Further, in step S4, the temperature of the high-temperature calcination is 500°C to 650°C, and the heating rate is 5 to 10°C / min. If the calcination temperature is too low, it is not conducive to the formation of a lead sulfate protective layer. If the calcination temperature is too high, it is easy to cause the CsPbBr3 crystal grains to be too large, affecting the luminescence efficiency.

[0024] Further, in step S4, the equipment for the high-temperature calcination includes a tube furnace and a muffle furnace.

[0025] On the other hand, the present invention also provides a CsPbBr3 inorganic perovskite composite material, which is prepared by using the described preparation method.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) By introducing thiocyanate ions in the present invention, during the preparation process of ball milling or grinding, silica gel can be used as a carrier to load CsPbBr3 on the surface and prevent CsPbBr3 from agglomerating. Under high-temperature calcination, lead sulfate protective layer is in-situ formed between thiocyanate and lead ions. Under the protection of lead sulfate, the surface defects are reduced, and the resistance of CsPbBr3 to external humidity, heat and other factors is greatly improved. It can also maintain green fluorescence emission in water. Since there is no organic ligand, the reduction of fluorescence efficiency during the long-term storage of the CsPbBr3 perovskite composite material is delayed, enhancing the stability of the CsPbBr3 perovskite composite material.

[0028] (2) The present invention does not need to use organic substances as ligands or solvents as reaction media, and the preparation is simpler, greener and more economical. Description of the Drawings

[0029] Figure 1 Photographs of the CsPbBr3 perovskite composite material prepared in Example 1 and its appearance in water;

[0030] Figure 2 Photographs of the CsPbBr3 perovskite composite material prepared in Example 2 and its appearance in water;

[0031] Figure 3 Photographs of the CsPbBr3 perovskite composite material prepared in Example 3 and its appearance in water;

[0032] Figure 4 Photographs of the CsPbBr3 perovskite composite material prepared in Example 4 and its appearance in water;

[0033] Figure 5 Photographs of the CsPbBr3 perovskite composite material prepared in Comparative Example 1 and its appearance in water;

[0034] Figure 6The CsPbBr3 perovskite composite material prepared in Comparative Example 2 and its photo in water;

[0035] Figure 7 The CsPbBr3 perovskite composite material prepared in Comparative Example 3 and its photo in water;

[0036] Figure 8 The photo of the CsPbBr3 perovskite composite material prepared in Comparative Example 4;

[0037] Figure 9 The XRD characterization diagram of the CsPbBr3 perovskite composite material prepared in Example 1;

[0038] Figure 10 The fluorescence emission spectrum of the CsPbBr3 perovskite composite material prepared in Example 1;

[0039] Figure 11 The fluorescence emission spectrum of the CsPbBr3 perovskite composite material prepared in Example 2;

[0040] Figure 12 The fluorescence emission spectrum of the CsPbBr3 perovskite composite material prepared in Example 3;

[0041] Figure 13 The fluorescence emission spectrum of the CsPbBr3 perovskite composite material prepared in Example 4;

[0042] Figure 14 The fluorescence emission spectrum of the CsPbBr3 perovskite composite material prepared in Comparative Example 2;

[0043] Figure 15 The fluorescence emission spectrum of the CsPbBr3 perovskite composite material prepared in Comparative Example 3. Detailed implementation mode

[0044] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments. Based on the given embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

[0045] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art.

[0046] The ball mill is a planetary ball mill, purchased from Changsha Miqi Instrument Co., Ltd.; the muffle furnace is purchased from Luoyang Sigma High Temperature Furnace Co., Ltd.; the reagents used in the following examples and comparative examples are all purchased from Shanghai Titan Technology Co., Ltd.

[0047] Example 1

[0048] In Example 1, the molar ratio of lead ions to thiocyanate ions is 1:1.

[0049] A preparation method of a CsPbBr3 inorganic perovskite composite material, characterized by comprising the following steps:

[0050] S1. Ball-mill 0.8083 g of Pb(SCN)2 (99%, RG), 0.4798 g of CsAc (99%, RG), and 2 g of silica gel (300-400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a first mixture;

[0051] S2. Ball-mill 0.9 g of KBr (≥99%, AR) and 2 g of silica gel (300-400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a second mixture;

[0052] S3. Mix and react the first mixture obtained in step S1 and the second mixture obtained in step S2, and ball-mill in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a crude product;

[0053] S4. Calcinate the crude product in a muffle furnace at 650 °C for 0.5 h with a heating rate of 5 °C / min to obtain the CsPbBr3 inorganic perovskite composite material, and the preparation is completed.

[0054] Example 2

[0055] Compared with Example 1, most of them are the same, except that 0.1215 g of KSCN (99%) is additionally introduced in step S1, and the molar ratio of lead ions to thiocyanate ions is 1:1.5.

[0056] A preparation method of a CsPbBr3 inorganic perovskite composite material, characterized by comprising the following steps:

[0057] S1. Ball-mill 0.8083 g of Pb(SCN)2 (99%, RG), 0.4798 g of CsAc (99%, RG), 0.1215 g of KSCN (99%), and 2 g of silica gel (300-400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a first mixture;

[0058] S2. Grind 0.9 g of KBr (≥99%, AR) and 2 g of silica gel (300 - 400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a second mixture;

[0059] S3. Mix and react the first mixture obtained in step S1 and the second mixture obtained in step S2, and grind in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a preliminary product;

[0060] S4. Calcinate the preliminary product in a muffle furnace at 650 °C for 0.5 h with a heating rate of 5 °C / min to obtain a CsPbBr3 inorganic perovskite composite material, and the preparation is completed.

[0061] Example 3

[0062] Compared with Example 2, most of them are the same, except that the additional KSCN introduced in step S1 is 0.2430 g, and the molar ratio of lead ions to thiocyanate ions is 1:2.

[0063] A method for preparing a CsPbBr3 inorganic perovskite composite material, characterized by comprising the following steps:

[0064] S1. Grind 0.8083 g of Pb(SCN)2 (99%, RG), 0.2430 g of KSCN (99%), 0.4798 g of CsAc (99%, RG), and 2 g of silica gel (300 - 400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a first mixture;

[0065] S2. Grind 0.9 g of KBr (≥99%, AR) and 2 g of silica gel (300 - 400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a second mixture;

[0066] S3. Mix and react the first mixture obtained in step S1 and the second mixture obtained in step S2, and grind in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a preliminary product;

[0067] S4. Calcinate the preliminary product in a muffle furnace at 650 °C for 0.5 h with a heating rate of 5 °C / min to obtain a CsPbBr3 inorganic perovskite composite material, and the preparation is completed.

[0068] Example 4

[0069] Compared with Example 1, most of them are the same, except that the reaction instrument used in steps S1, S2, and S3 is a pulverizer.

[0070] A method for preparing a CsPbBr3 inorganic perovskite composite material, characterized by comprising the following steps:

[0071] S1. Crush 0.8083 g of Pb(SCN)2 (99%, RG), 0.4798 g of CsAc (99%, RG), and 2 g of silica gel (300 - 400 mesh, AR) in a pulverizer for 5 min to obtain a first mixture;

[0072] S2. Crush 0.9 g of KBr (≥99%, AR) and 2 g of silica gel (300 - 400 mesh, AR) in a pulverizer for 5 min to obtain a second mixture;

[0073] S3. Mix and react the first mixture obtained in step S1 and the second mixture obtained in step S2, and crush in a pulverizer for 5 min to obtain a preliminary product;

[0074] S4. Calcinate the preliminary product in a muffle furnace at 650 °C for 0.5 h with a heating rate of 5 °C / min to obtain the CsPbBr3 inorganic perovskite composite material, and the preparation is completed.

[0075] Comparative Example 1

[0076] Compared with Example 1, most of them are the same, except that the inorganic lead salt used in step S1 is lead acetate trihydrate, which does not contain thiocyanate ions.

[0077] A method for preparing a CsPbBr3 inorganic perovskite composite material, characterized by comprising the following steps:

[0078] S1. Ball-mill 0.9483 g of Pb(Ac)2·3H2O (99%, RG), 0.4798 g of CsAc (99%, RG), and 2 g of silica gel (300 - 400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a first mixture;

[0079] S2. Ball-mill 0.9 g of KBr (≥99%, AR) and 2 g of silica gel (300 - 400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a second mixture;

[0080] S3. Mix and react the first mixture obtained in step S1 and the second mixture obtained in step S2, and ball-mill in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a preliminary product;

[0081] S4. Calcinate the preliminary product in a muffle furnace at 650 °C for 0.5 h with a heating rate of 5 °C / min to obtain the CsPbBr3 inorganic perovskite composite material, and the preparation is completed.

[0082] Comparative Example 2

[0083] Compared with Example 1, most of them are the same, except that the lead source used in step S1 is the organic lead salt lead stearate ((C18 H 35 (O₂)₂Pb), without thiocyanate ions. A preparation method of a CsPbBr₃ inorganic perovskite composite material, characterized by comprising the following steps:

[0084] S1. Grind 1.9354 g of (C 18 H 35 O₂)₂Pb (lead stearate, 98% +, RG), 0.4798 g of CsAc, and 2 g of silica gel in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a first mixture;

[0085] S2. Grind 0.9 g of KBr (99.9%, RG) and 2 g of silica gel in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a second mixture;

[0086] S3. Mix and react the first mixture obtained in step S1 and the second mixture obtained in step S2, and grind in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a crude product;

[0087] S4. Calcinate the crude product in a muffle furnace at 650 °C for 0.5 h with a heating rate of 5 °C / min to obtain a CsPbBr₃ inorganic perovskite composite material, and the preparation is completed.

[0088] Comparative Example 3

[0089] Compared with Example 1, most of them are the same, except that the calcination temperature used in step S4 is 700 °C. A preparation method of a CsPbBr₃ inorganic perovskite composite material, characterized by comprising the following steps:

[0090] S1. Grind 0.8083 g of Pb(SCN)₂ (99%, RG), 0.4798 g of CsAc (99%, RG), and 2 g of silica gel (300 - 400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a first mixture;

[0091] S2. Grind 0.9 g of KBr (≥99%, AR) and 2 g of silica gel (300 - 400 mesh, AR) in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a second mixture;

[0092] S3. Mix and react the first mixture obtained in step S1 and the second mixture obtained in step S2, and grind in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a crude product;

[0093] S4. Calcinate the crude product in a muffle furnace at 700 °C for 0.5 h with a heating rate of 5 °C / min to obtain a CsPbBr₃ inorganic perovskite composite material, and the preparation is completed.

[0094] Comparative Example 4

[0095] Compared with Example 1, most of them are the same, except that 2 mL of DMF solvent is additionally added in Steps S1 and S2.

[0096] A method for preparing a CsPbBr3 inorganic perovskite composite material, characterized by comprising the following steps:

[0097] S1. Ball-mill 0.8083 g of Pb(SCN)2 (99%, RG), 0.4798 g of CsAc (99%, RG), 0.1215 g of KSCN (99%), 2 g of silica gel (300 - 400 mesh, AR) and 2 mL of DMF in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a first mixture;

[0098] S2. Ball-mill 0.9 g of KBr (≥99%, AR), 2 g of silica gel (300 - 400 mesh, AR) and 2 mL of DMF in a ball mill for 2 h at a rotation speed of 800 revolutions per minute to obtain a second mixture;

[0099] S3. Mix and react the first mixture obtained in Step S1 and the second mixture obtained in Step S2, ball-mill in a ball mill for 2 h at a rotation speed of 800 revolutions per minute, centrifuge to remove the solvent, and dry to obtain a preliminary product;

[0100] S4. Calcinate the preliminary product in a muffle furnace at 650 °C for 0.5 h with a heating rate of 5 °C / min to obtain a CsPbBr3 inorganic perovskite composite material, and the preparation is completed.

[0101] The photos of the products obtained in the above Examples 1 to 4 and Comparative Examples 1 to 4 are as Figures 1 to 8 shown. It can be seen from the figure that Examples 1 to 4 are light green, Comparative Example 1 is white, Comparative Example 2 is white, Comparative Example 3 is yellow, and Comparative Example 4 is white. Lead thiocyanate is used as the lead source in Examples 1 to 4. On the premise that lead thiocyanate is used as the lead source, potassium thiocyanate with different molar ratios (0.5 and 1) is additionally added in Examples 2 and 3 to introduce thiocyanate ions. Example 4 uses a crusher to prepare the CsPbBr3 composite material. As a carrier, silica can effectively isolate the generated CsPbBr3 during ball milling or crushing to prevent agglomeration. During the calcination process, thiocyanate ions react with lead ions at high temperature to form a lead sulfate protective layer.

[0102] Figure 9XRD characterization of Example 1. Diffraction peaks at 15.2°, 21.5°, 26.3°, 30.7°, 34.3°, 37.8°, 43.7°, 46.6°, and 49.4° in the range of 10° - 50° correspond to crystal planes (100), (110), (111), (200), (201), (121), (202), (212), and (301) respectively. The complete appearance of the peaks proves the successful preparation of CsPbBr3.

[0103] Figures 10 to 15 They are the fluorescence emission spectra of Examples 1 - 4 and Comparative Examples 2 - 3 respectively. It can be seen from the figure that the positions of the fluorescence emission peaks of Examples 1 - 4 are all around 515 nm. The fluorescence emission peak intensity of Example 1 is 1077, that of Example 2 is 1155, that of Example 3 is 1197, and that of Example 4 is 1033. While the position of the fluorescence emission peak of Comparative Example 2 is blue-shifted to 491 nm, and the lowest fluorescence emission intensity is 200. The position of the fluorescence emission peak of Comparative Example 3 is red-shifted to 520 nm, and the fluorescence emission peak intensity is 572.

[0104] In Comparative Example 1, lead acetate trihydrate was used as the lead source without thiocyanate. The final sample color was white and had no fluorescence, so there was no fluorescence emission spectrum. Under calcination, CsPbBr3 was affected by high temperature resulting in fluorescence quenching. In Comparative Example 2, organic lead salt lead stearate was used instead of lead thiocyanate. After calcination, it turned white. The stearate group was easily cracked at high temperature, losing the protective effect on CsPbBr3. At 650 °C calcination, CsPbBr3 was exposed to high temperature, and the lattice expanded, resulting in a blue shift of the fluorescence emission peak and only weak fluorescence. Comparative Example 3 was based on Example 1 and only changed the calcination temperature from the original 650 °C to 700 °C. After calcination, the sample turned yellow, significantly lower than that of Examples 1 - 4. The reason is that too high calcination temperature will promote the growth and aggregation of CsPbBr3 perovskite grains at high temperature, thus causing the weakening of the quantum confinement effect, and at the same time, the fluorescence emission peak intensity decreases and redshifts. The powder obtained in Comparative Example 4 was a white powder because after adding a common solvent and without it acting as an organic ligand, the perovskite was dissolved and damaged by the solvent, and the corresponding composite material could not be obtained.

[0105] When CsPbBr3 is affected by moisture and air humidity, it is very easy to transform into non-luminescent Cs4PbBr6 or CsPb2Br5. Samples prepared using organic substances as ligands usually have difficulty maintaining stable luminescence in water, and fluorescence is easily quenched during long-term storage. From Figures 1 to 8It can be seen that for the samples prepared in Examples 1 to 4 by introducing different amounts of thiocyanate ions, whether by ball milling or pulverization, they can remain green in water. Comparative Example 1 and Comparative Example 2 are samples prepared without introducing thiocyanate ions and have almost no fluorescence, proving that lead sulfate formed at high temperature after introducing thiocyanate ions can make the samples less affected by moisture and enhance their stability in water. From the position and intensity of the fluorescence emission peak, the more thiocyanate ions are introduced, the higher the intensity of the fluorescence emission peak, and there is no obvious change in the position of the emission peak, indicating that the introduction of thiocyanate ions can, to a certain extent, protect CsPbBr3 from being damaged in crystal structure at high temperature and enhance its resistance in water.

[0106] Although the present invention has been described in detail above with general descriptions, specific embodiments and experiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A preparation method of a CsPbBr3 inorganic perovskite composite material, characterized in that, It includes the following steps: S1. Mix and react thiocyanate, inorganic lead salt, and inorganic cesium salt with the first carrier to obtain a first mixture; S2. Mix and react inorganic bromide salt with the second carrier to obtain a second mixture; S3. Mix and react the first mixture and the second mixture to obtain a primary product; S4. Calcinate the primary product at high temperature to obtain a CsPbBr3 inorganic perovskite composite material, and the preparation is completed.

2. The preparation method of a CsPbBr3 inorganic perovskite composite material according to claim 1, characterized in that, In step S1, the thiocyanate includes KSCN, NaSCN, Pb(SCN)2, Al(SCN)3; The inorganic lead salt includes PbBr2, Pb(SCN)2; The inorganic cesium salt includes CsBr, CsAc.

3. The preparation method of a CsPbBr3 inorganic perovskite composite material according to claim 1, characterized in that, In step S1, the first carrier includes molecular sieve, silica gel, quartz sand; In step S2, the second carrier includes molecular sieve, silica gel, quartz sand.

4. The preparation method of a CsPbBr3 inorganic perovskite composite material according to claim 1, wherein In step S1, the molar ratio of thiocyanate ion in the thiocyanate, lead ion in the inorganic lead salt, cesium ion in the inorganic cesium salt, and the first carrier is 0.5 - 2:1:0.5 - 1:1 - 4.

5. The preparation method of a CsPbBr3 inorganic perovskite composite material according to claim 1, characterized in that, In step S2, mix and react inorganic bromide salt, thiocyanate, and the second carrier to obtain a second mixture; In steps S1 and S2, the molar ratio of thiocyanate ion in the thiocyanate to lead ion in the inorganic lead salt is 0.5 - 2:

1.

6. The preparation method of a CsPbBr3 inorganic perovskite composite material according to claim 1, characterized in that, In step S2, the inorganic bromide salt includes KBr, PbBr2, NaBr; The molar ratio of the inorganic bromide salt to the second carrier is 0.5 - 1:

2.

7. The preparation method of a CsPbBr3 inorganic perovskite composite material according to claim 1, wherein, In step S3, the molar ratio of lead element in the first mixture to bromine element in the second mixture is 0.5 - 1.5:

1.

8. The preparation method of a CsPbBr3 inorganic perovskite composite material according to claim 1, wherein, In steps S1, S2, and S3, the mixing reaction includes ball milling mixing and grinding mixing.

9. The preparation method of a CsPbBr3 inorganic perovskite composite material according to claim 1, characterized in that, In step S4, the temperature of the high-temperature calcination is 500°C - 650°C, and the heating rate is 5 - 10°C / min.

10. A CsPbBr3 inorganic perovskite composite material, which is prepared by using the preparation method according to any one of claims 1 - 9.

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