Method for preparing indium-based perovskite single crystal and method for purifying indium halide

Abstract

The application relates to the technical field of perovskite material processes, in particular to a preparation method of an indium-based perovskite single crystal and a purification method of indium halide. The preparation method of the indium-based perovskite single crystal comprises the following steps: providing a solution containing indium halide, wherein the pH of the solution is less than 4.0; mixing the solution containing indium halide with acetonitrile, and then performing drying treatment to obtain the indium-based perovskite single crystal; wherein the solution containing indium halide is obtained by dissolving indium halide in hydrohalic acid, and the structural formula of the obtained indium-based perovskite single crystal is (OH3)3InX6; or the solution containing indium halide is obtained by dissolving indium halide and doped metal halide in hydrohalic acid, and the structural formula of the obtained indium-based perovskite single crystal is (OH3)3InX6:M; X is halogen, and M is a doped metal. The preparation method of the indium-based perovskite single crystal provided by the application not only has simple process steps, but also has mild conditions and less pollution, so that the indium-based perovskite single crystal can be prepared at low cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of perovskite material process, and particularly relates to a preparation method of indium-based perovskite single crystal and a purification method of indium halide. BACKGROUND

[0002] High-purity indium trichloride (InCl3) is a main raw material for preparing III-V compound semiconductor materials, solar cell materials and indium tin oxide (ITO) thin films, and is widely used in fields of organic catalysts, organic synthesis, electronic industry and the like. China is rich in metal indium resources and ranks first in the world. However, the high-purity anhydrous indium trichloride technology is not mature, resulting in high price.

[0003] In nature, indium and antimony have similar chemical properties and ionic radii, so they usually coexist. Although the purity of indium trichloride can generally reach 4N (i.e. 99.99%), further purification is not easy to achieve. At present, the preparation methods of indium trichloride mainly include direct chlorination method, oxide chlorination method, organic solvent method, stepwise heating chlorination method and the like. The above preparation methods are strict in temperature control, and have the disadvantages of complex equipment, low yield, difficult post-treatment and serious environmental pollution. SUMMARY

[0004] An object of the application is to provide a preparation method of indium-based perovskite single crystal, aiming to solve the technical problem of how to simply and low-costly prepare the indium-based perovskite single crystal.

[0005] To achieve the above object, the technical solution adopted by the application is as follows:

[0006] The application provides a preparation method of indium-based perovskite single crystal, comprising:

[0007] A solution containing indium halide is provided, and the pH of the solution is less than 4.0;

[0008] The solution containing indium halide is mixed with acetonitrile, and then dried to obtain the indium-based perovskite single crystal;

[0009] In the preparation method,

[0010] The solution containing indium halide is obtained by dissolving indium halide in hydrohalic acid, and the structural formula of the obtained indium-based perovskite single crystal is (OH3)3InX6; or

[0011] The solution containing indium halide is obtained by dissolving indium halide and doped metal halide in hydrohalic acid, and the structural formula of the obtained indium-based perovskite single crystal is (OH3)3InX6:M;

[0012] X is halogen, and M is a doped metal.

[0013] The application provides a preparation method of an indium-based perovskite single crystal.

[0014] Another object of the application is to provide a method for purifying indium halide, aiming to solve the technical problem of how to further improve the purity of indium halide.

[0015] To achieve the above objects, the application adopts the following technical solutions:

[0016] The application provides a method for purifying indium halide, comprising the following steps:

[0017] Step 1: providing indium halide raw material to be purified;

[0018] Step 2: dissolving the indium halide raw material to be purified in a hydrogen halide acid to obtain a dissolution solution with pH<4.0;

[0019] Step 3: mixing the dissolution solution with acetonitrile, and then performing drying treatment to obtain an indium-based perovskite single crystal;

[0020] Step 4: performing fluorescence analysis on the indium-based perovskite single crystal;

[0021] If there is no yellow light or red light emission, the indium-based perovskite single crystal is heated and dehydrated to obtain a purified indium halide material;

[0022] If there is yellow light or red light emission, steps 2 and 3 are repeated with the indium-based perovskite single crystal as the raw material until there is no yellow light or red light emission, and then the indium-based perovskite single crystal is heated and dehydrated to obtain a purified indium halide material.

[0023] The method for purifying indium halide provided by the application can effectively remove the antimony impurities in the indium halide by dissolving the indium halide raw material to be purified in a hydrogen halide solution and then mixing with acetonitrile to obtain an indium-based perovskite single crystal. Subsequently, through fluorescence analysis, if the indium-based perovskite single crystal does not emit yellow light or red light, it can be considered that the antimony impurities have been removed. Finally, the indium-based perovskite single crystal obtained by recrystallization is heated and dehydrated to remove water, so that an ultra-high purity (purity greater than 5N) indium halide material can be obtained. Such high-purity indium halide material can be well applied in the fields of organic catalysts, organic synthesis, electronic industry, etc. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0025] Figure 1 is an optical photo of the indium-based perovskite single crystal (OH3)3InCl6 provided by the embodiments of the present application;

[0026] Figure 2 is a fluorescence spectrum diagram of the indium-based perovskite single crystal (OH3)3InCl6 and (OH3)3InCl6:Sb provided by the embodiments of the present application;

[0027] Figure 3 is a quantum yield diagram of the indium-based perovskite single crystal (OH3)3InCl6 provided by the embodiments of the present application;

[0028] Figure 4 is a quantum yield diagram of the indium-based perovskite single crystal (OH3)3InCl6:Sb provided by the embodiments of the present application;

[0029] Figure 5 is an XRD diagram of the indium-based perovskite single crystal (OH3)3InCl6 and (OH3)3InCl6:Sb provided by the embodiments of the present application;

[0030] Figure 6 is a relationship diagram between the feeding ratio of SbCl3 and the actual doping amount in the preparation process of the indium-based perovskite single crystal (OH3)3InCl6:Sb provided by the embodiments of the present application. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application will be further described in detail in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0032] In the present application, the term "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it.

[0033] In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or similar expressions means any combination of these items, including any combination of single item or multiple items.

[0034] It should be understood that the magnitude of the serial number of the above processes does not mean the order of execution in various embodiments of the present application, and part or all of the steps can be executed in parallel or in sequence, and the execution order of the processes should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0036] The weight of the related components mentioned in the specification of the embodiments of the present application can not only refer to the specific content of each component, but also represent the weight ratio relationship between each component, therefore, as long as the content of the related components in the specification of the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass mentioned in the specification of the embodiments of the present application can be μg, mg, g, kg and other mass units commonly known in the chemical field.

[0037] The terms "first", "second" are only for the purpose of description, used to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX can also be referred to as the second XX, and similarly, the second XX can also be referred to as the first XX. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features.

[0038] The first aspect of the embodiments of the present application provides a preparation method of an indium-based perovskite single crystal, specifically, for the preparation of an indium-based perovskite single crystal with a structural formula of (OH3)3InX6, which comprises the following steps:

[0039] S011: providing a solution containing indium halide, the pH of the solution is less than 4.0; the solution containing indium halide is obtained by dissolving indium halide in hydrohalic acid;

[0040] S012: mixing the solution containing indium halide and acetonitrile, and then performing drying treatment to obtain an indium-based perovskite single crystal with a structural formula of (OH3)3InX6.

[0041] For the preparation of an indium-based perovskite single crystal with a structural formula of (OH3)3InX6:M, the following steps are included:

[0042] S021: providing a solution containing indium halide, the pH of the solution is less than 4.0; the solution containing indium halide is obtained by dissolving indium halide and doping metal halide in hydrohalic acid;

[0043] S022: mixing the solution containing indium halide and acetonitrile, and then performing drying treatment to obtain an indium-based perovskite single crystal with the structural formula of (OH3)3InX6:M.

[0044] The preparation method of the indium-based perovskite single crystal provided in the embodiments of the present application can obtain an indium-based perovskite single crystal with the structural formula of (OH3)3InX6 or (OH3)3InX6:M (wherein X is halogen, M is a doping metal such as antimony, OH3 + is a protonated water molecule) by dissolving relevant raw materials in hydrohalic acid to prepare a solution, mixing the solution with acetonitrile to perform reaction, and then drying. The preparation process is simple in process steps, mild in conditions, and less polluting, and thus the indium-based perovskite single crystal can be prepared at low cost.

[0045] The above-mentioned indium halide refers to indium trihalide, the doping metal halide refers to doping metal trihalide such as antimony trihalide, and the hydrohalic acid is an aqueous solution of hydrogen halide. Taking hydrochloric acid as an example, the hydrochloric acid solution can be a hydrochloric acid solution with a mass percentage of 37%.

[0046] In an embodiment, in step S011 or step S021, the concentration of indium halide in the solution containing indium halide is 2-5 mol / L. Specifically, indium halide (or indium halide and doping metal halide) is dissolved in hydrohalic acid, and then the pH of the solution is adjusted to be less than 4.0 (such as pH=2.0, 2.5, 3.0, 3.5, 3.8, etc.) by using the hydrohalic acid to obtain the solution containing indium halide with the above-mentioned concentration range.

[0047] Specifically, the halogen in indium halide and the hydrohalic acid is the same (or the halogen in indium halide, doping metal halide and the hydrohalic acid is the same), and the halogen can be one of fluorine, chlorine, bromine and iodine. For example, indium trifluoride (or indium trifluoride and doping metal trifluoride) is dissolved in hydrofluoric acid to obtain a solution containing indium trifluoride, or indium trichloride (or indium trichloride and doping metal trichloride) is dissolved in hydrochloric acid to obtain a solution containing indium trichloride, or indium tribromide (or indium tribromide and doping metal tribromide) is dissolved in hydrobromic acid to obtain a solution containing indium tribromide.

[0048] Further, when the indium halide-containing solution contains a doped metal halide, i.e. the indium halide and the doped metal halide are dissolved in the hydrohalic acid to obtain the indium halide-containing solution, the doped metal halide is selected from antimony halide, and the molar ratio of the indium halide and the antimony halide is 1:(0.001-0.1). By doping with antimony, the fluorescence quantum yield of the indium-based perovskite single crystal can be further improved. Further, the intermediate phase lead-free indium-based perovskite single crystal material of the prepared Sb-doped (OH3)3InCl6 is stable in properties, high in product purity, and has a fluorescence quantum yield of more than 90%, and has a broad application prospect in fluorescent lamps, electroluminescent devices, solid-state lasers and the like.

[0049] Further, the (OH3)3InCl6:Sb lead-free indium-based perovskite single crystal is prepared, wherein 10% of SbCl3 by mole of InCl3 is added during the preparation process, and the actual doping amount of the final single crystal product is only 0.39%, indicating that the doping efficiency of Sb is very low, which lays a solid foundation for purifying indium trichloride by using the intermediate phase lead-free indium-based perovskite single crystal material of (OH3)3InCl6.

[0050] In an embodiment, in step S012 or step S022, the volume ratio of the indium halide-containing solution to acetonitrile is (1-2):1. The indium halide-containing solution and acetonitrile are mixed to react, and recrystallization is performed to obtain the indium-based perovskite single crystal.

[0051] Further, the temperature of the drying treatment is 28-32°C; further, after the indium halide-containing solution and acetonitrile are mixed, the mixture is first placed for 20-25 h, and then subjected to the drying treatment. Under this condition, the indium-based perovskite single crystal can be better obtained.

[0052] The second aspect of the embodiments of the present application provides a method for purifying indium halide, comprising the following steps:

[0053] Step 1, providing an indium halide raw material to be purified;

[0054] Step 2, dissolving the indium halide raw material to be purified in a hydrohalic acid to obtain a dissolution solution with a pH of less than 4.0;

[0055] Step 3, mixing the dissolution solution and acetonitrile, and then performing a drying treatment to obtain an indium-based perovskite single crystal;

[0056] Step 4, performing fluorescence analysis on the indium-based perovskite single crystal;

[0057] If there is no yellow light or red light emission, the indium-based perovskite single crystal is subjected to a heating dehydration treatment to obtain a purified indium halide material;

[0058] If there is yellow or red light emission, repeat steps 2 and 3 until there is no yellow or red light emission, and then perform heat dehydration to obtain the purified indium halide material.

[0059] The method for purifying indium halide provided in the embodiments of the present application can effectively remove the antimony impurities in the indium halide by dissolving the indium halide to be purified in a hydrohalic acid solution and then mixing with acetonitrile to obtain indium-based perovskite single crystals. If the indium-based perovskite single crystals do not emit yellow or red light through subsequent fluorescence analysis, it can be basically considered that the antimony impurities have been removed. Finally, the indium-based perovskite single crystals obtained through recrystallization are subjected to heat dehydration to remove water, so that an ultra-high purity (purity greater than 5N) indium halide material can be obtained. Such high-purity indium halide material can be well applied in the fields of organic catalysts, organic synthesis, electronic industry, etc.

[0060] In step 1, the indium halide to be purified is the indium trihalide to be purified. The method for purifying indium halide provided in the embodiments of the present application is mainly to remove the antimony in the indium trihalide. The fluorescence intensity of (OH3)3InX6 doped with antimony is obviously enhanced compared with that of the undoped one, and strong yellow and red light emission is shown under different excitation light excitation. Therefore, the embodiments of the present application can generate intermediate phase lead-free indium-based perovskite single crystal material to perform fluorescence analysis on the indium-based perovskite single crystals, and determine whether the antimony is removed by using the judgment method of whether there is yellow or red light emission to purify the indium halide material.

[0061] In step 2, the halogen in the hydrohalic acid is the same as that in the indium halide to be purified. For example, the indium trifluoride to be purified is dissolved in hydrofluoric acid to obtain a dissolution solution containing indium trifluoride, or the indium trichloride to be purified is dissolved in hydrochloric acid to obtain a dissolution solution containing indium trichloride. Further, the concentration of the indium halide to be purified in the dissolution solution is 2-5 mol / L. Specifically, the indium halide to be purified is dissolved in the hydrohalic acid, and then the pH of the solution is adjusted to be less than 4.0 by using the hydrohalic acid to obtain the dissolution solution with the above concentration range.

[0062] In step 3, the volume ratio of the dissolution solution to acetonitrile is (1-2):1. The dissolution solution containing indium halide is mixed with acetonitrile to perform recrystallization, which can effectively remove the antimony in the indium halide, so as to obtain indium trihalide with higher purity. Further, the temperature of the above drying treatment is 28-32℃; further, after the dissolution solution and acetonitrile are mixed, they are first placed for 20-25h, and then subjected to drying treatment.

[0063] In step 4, the dehydration step includes: heat treating the indium-based perovskite single crystal at a temperature of ≥ 650℃ for 3-4h under the protection of an inert atmosphere. Specifically, the inert atmosphere can be nitrogen or an inert gas. The heat treatment temperature is ≥ 650℃, the higher the temperature, the higher the indium content, and the heat treatment time is 3h, and further prolonging the time does not significantly improve the conversion rate of indium. In order to save costs, the heat treatment temperature is further selected to be 650℃, and the time is 3h. The present application takes the purification of indium trichloride as an example. The indium trichloride is dissolved in hydrochloric acid, and then mixed with acetonitrile for recrystallization, which can effectively remove the antimony in the indium trichloride. Through fluorescence analysis, if there is no yellow or red fluorescence (if there is yellow or red fluorescence, repeat the steps of dissolving and recrystallizing until there is no yellow or red fluorescence), it can be considered that the antimony therein is completely removed (the antimony is reduced to less than ppm). Subsequently, dehydration by heating can remove water

[0064] The high-purity indium trichloride material can be better applied to the fields of organic catalysts, organic synthesis, electronic industry, etc.

[0065] The following will be described in conjunction with specific examples.

[0066] Example 1

[0067] A method for preparing a lead-free indium-based perovskite single crystal material, comprising the following steps:

[0068] Preparation of an InCl3-containing solution: 5mmol of InCl3 is dissolved in 1mL of 37% concentrated hydrochloric acid to obtain an InCl3-containing solution with a molar concentration of 5mol / L and a pH of <4.0;

[0069] Mixing the above InCl3-containing solution and acetonitrile solution in a volume ratio of 2:1, and after the reaction is complete, let it stand for 24h, then dry the product at 30℃ to obtain a lead-free indium-based perovskite single crystal represented by (OH3)3InCl6.

[0070] Example 2

[0071] A method for preparing a lead-free indium-based perovskite single crystal material, comprising the following steps:

[0072] A solution containing InCl3and SbCl3is prepared: 5 mmol of InCl3and 0.005 mmol of SbCl3are dissolved in 1 mL of 37% concentrated hydrochloric acid to obtain a solution of InCl3with a molar concentration of 5 mol / L and a pH < 4.0; the above solution and acetonitrile solution are mixed in a volume ratio of 2:1, and after sufficient reaction, the product is allowed to stand for 24 h,

[0073] The product is then dried at 30°C to obtain the Sb-doped lead-free indium-based perovskite single crystal represented by (OH3)3InCl6:Sb.

[0074] Example 3

[0075] A method for purifying indium trichloride, comprising the following steps: 5 mmol of InCl3to be purified is dissolved in 1 mL of 37% concentrated hydrochloric acid to obtain a solution containing InCl3with a molar concentration of 5 mol / L and a pH < 4.0;

[0076] The above solution and acetonitrile solution are mixed in a volume ratio of 2:1, and after sufficient reaction, the product is allowed to stand for 24 h, and then the product is dried at 30°C to obtain an indium-based perovskite single crystal.

[0077] The indium-based perovskite single crystal is subjected to fluorescence analysis: there is no yellow or red light emission; the indium-based perovskite single crystal is then subjected to heat dehydration (650°C heat treatment for 3 h under a nitrogen atmosphere) to obtain an indium trichloride material with a purity greater than 5N.

[0078] Property testing:

[0079] (OH3)3InCl6 obtained in Example 1 and (OH3)3InCl6:Sb obtained in Example 2 are subjected to fluorescence spectrum, X-ray diffraction (XRD), and inductively coupled plasma (ICP) property testing.

[0080] Figure 1 An optical photograph of the lead-free indium-based perovskite single crystal (OH3)3InCl6 prepared in Example 1. Figure 2 The fluorescence spectra of the lead-free indium-based perovskite single crystal (OH3)3InCl6 prepared in Example 1 and the lead-free indium-based perovskite single crystal (OH3)3InCl6:Sb prepared in Example 2, under the same testing conditions, the fluorescence intensity of the sample of Example 2 doped with Sb is obviously enhanced compared with the fluorescence intensity of the sample of Example 1 without doping, and under different excitation light excitations (280 nm and 290 nm), strong yellow-red light double emission is exhibited, while Example 1 does not emit light.

[0081] Figure 3is a quantum yield graph of the undoped (OH3)3InCl6 lead-free indium-based perovskite single crystal prepared in Example 1, whose fluorescence quantum yield is only 2.47%, less than 3%, while Figure 4 is a quantum yield graph of the (OH3)3InCl6:Sb lead-free indium-based perovskite single crystal prepared in Example 2, whose fluorescence quantum yield can reach 94.01%, indicating that the fluorescence quantum yield of the indium-based perovskite single crystal can be further improved by antimony doping

[0082] Figure 5 is an XRD analysis graph of the (OH3)3InCl6 lead-free indium-based perovskite single crystal obtained in Example 1 and the (OH3)3InCl6:Sb lead-free indium-based perovskite single crystal obtained in Example 2, indicating that the XRD spectrum of the (OH3)3InCl6 lead-free indium-based perovskite single crystal prepared in Example 1 is basically consistent with the standard card, further confirming that the (OH3)3InCl6 lead-free indium-based perovskite prepared in Example 1 has high purity. The XRD spectrum of the (OH3)3InCl6:Sb lead-free indium-based perovskite single crystal prepared in Example 2 does not shift compared with Example 1, which is because the type of antimony ion doping belongs to substitutional doping, which exists in the lattice by replacing the position of indium ion in (OH3)3InCl6. Since the ionic radius of Sb is very close to that of In, the XRD spectrum does not change significantly after Sb doping.

[0083] Through ICP testing of the (OH3)3InCl6 lead-free indium-based perovskite single crystal obtained in Example 1 and the (OH3)3InCl6:Sb lead-free indium-based perovskite obtained in Example 2, the results are shown in Figure 6 , indicating that the doping efficiency of Sb is very low, and when the amount of SbCl3 is increased to 10% of the feed, the actual doping amount is only 0.39%, which lays a solid foundation for purifying indium trichloride by generating an intermediate phase of (OH3)3InCl6 lead-free indium-based perovskite single crystal and then heating and dehydrating in Example 3.

[0084] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing an indium-based perovskite single crystal, characterized by, The application relates to a method for purifying halogenated indium, comprising the following steps: a solution containing halogenated indium is provided, wherein the pH of the solution is less than 4.0; the solution containing halogenated indium is mixed with acetonitrile, and then a drying treatment is performed to obtain an indium-based perovskite single crystal; wherein, the solution containing halogenated indium is obtained by dissolving halogenated indium in a hydrogen halide acid, and the structure formula of the obtained indium-based perovskite single crystal is (OH3)3InX6; or the solution containing halogenated indium is obtained by dissolving halogenated indium and a doped metal halide in a hydrogen halide acid, and the structure formula of the obtained indium-based perovskite single crystal is (OH3)3InX6:M; X is halogen, and M is a doped metal.

2. The production method according to claim 1, wherein In the solution containing halogenated indium, the concentration of halogenated indium is 2-5 mol / L.

3. The production method according to claim 2, wherein When the solution containing halogenated indium contains a doped metal halide, the doped metal halide is selected from antimony halide, and the feeding molar ratio of the halogenated indium and the antimony halide is 1:(0.001-0.1).

4. The production method according to claim 1, wherein The halogen in the halogenated indium and the hydrogen halide acid is the same; or The halogen in the halogenated indium, the doped metal halide and the hydrogen halide acid is the same.

5. The production method according to claim 1, wherein The volume ratio of the solution containing halogenated indium to the acetonitrile is (1-2):

1.

6. The production method according to any one of claims 1 to 5, wherein The temperature of the drying treatment is 28-32 DEG C; and / or After the solution containing halogenated indium is mixed with acetonitrile, the mixture is first placed for 20-25 h, and then the drying treatment is performed.

7. A method for purifying indium halide, characterized by, The application further relates to a method for purifying halogenated indium, comprising the following steps: Step 1, providing halogenated indium raw material to be purified; Step 2, dissolving the halogenated indium raw material to be purified in a hydrogen halide acid to obtain a dissolution solution with pH less than 4.0; Step 3, mixing the dissolution solution with acetonitrile, and then performing a drying treatment to obtain an indium-based perovskite single crystal; Step 4, performing fluorescence analysis on the indium-based perovskite single crystal: If there is no yellow light or red light emission, the indium-based perovskite single crystal is heated and dehydrated to obtain a purified halogenated indium material; If there is yellow light or red light emission, the indium-based perovskite single crystal is used as raw material to repeat steps 2 and 3 until there is no yellow light or red light emission, and then the heating and dehydration are performed to obtain a purified halogenated indium material.

8. The purification method according to claim 7, characterized by, The concentration of the halogenated indium raw material to be purified in the dissolution solution is 2-5 mol / L; and / or The volume ratio of the dissolution solution to the acetonitrile is (1-2):

1.

9. The purification method according to claim 7, characterized by, The halogen in the halogenated indium raw material to be purified and the hydrogen halide acid is the same; and / or The temperature of the drying treatment is 28-35 DEG C; and / or After the dissolution solution is mixed with acetonitrile, the mixture is first placed for 20-25 h, and then the drying treatment is performed.

10. Purification method according to any one of claims 7 to 9, characterized in that, The step of heating and dehydration comprises: under the protection of an inert atmosphere, the indium-based perovskite single crystal is heat-treated at a temperature of greater than or equal to 650 DEG C for 3-4 h.

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