Preparation process and application of perovskite-based microcrystalline material

Abstract

The present application relates to the field of microcrystalline materials, and in particular to a perovskite-based microcrystalline material, its preparation process and application. The preparation process of the perovskite-based microcrystalline material specifically includes the following steps: S1: preparation of site material solution; S2: addition of framework particle raw materials; S3: preliminary synthesis of microcrystalline material; S4: preparation of composite microcrystalline material. The perovskite-based microcrystalline material prepared in the present application can effectively overcome the internal defects in the material, thereby avoiding the loss of photoelectric performance, and can ensure that the perovskite material has excellent stability under long-term illumination, high temperature and humidity environment, and still maintains good self-properties in high humidity environment, avoiding decomposition, and thus has very excellent application value.

Description

Technical Field

[0001] The present application relates to the field of microcrystalline materials, and in particular to a perovskite-based microcrystalline material and its preparation process and application. Background Art

[0002] Perovskite-based microcrystalline materials, an emerging class of semiconductor materials, have garnered widespread attention in recent years due to their exceptional optoelectronic properties. Based on a perovskite structure, these specialized microcrystalline materials possess unique optoelectronic properties, making them a research hotspot across numerous application areas. Due to their exceptional performance, these materials are finding increasing application in solar cells, sensors, electronic products, and testing equipment.

[0003] However, as consumers' performance demands for products in the fields of solar cells, sensors, and electronics continue to increase, the performance of perovskite-based microcrystalline materials is also increasing. Although perovskite-based microcrystalline materials have many advantages, there are still some problems that need to be solved. For example, the stability of perovskite materials under long-term light, high temperature, and humidity environments is still insufficient, which is a major challenge for practical applications; the organic components in organic-inorganic hybrid perovskite materials may cause the material to decompose, affecting its stability and service life; defects in perovskite materials can lead to energy efficiency loss, affecting its optoelectronic performance, etc.

[0004] Therefore, in order to effectively solve the above problems, the present application provides a perovskite-based microcrystalline material and a preparation process thereof. The perovskite-based microcrystalline material prepared in the present application can effectively overcome the internal defects in its material, thereby avoiding the loss of photoelectric performance, and can ensure that the perovskite material has excellent stability under long-term light, high temperature and humidity environments, and still maintains good self-properties in high humidity environments, avoiding decomposition, and thus has very excellent application value. Summary of the Invention

[0005] In order to solve the above problems, the first aspect of the present application provides a preparation process of a perovskite-based microcrystalline material, which specifically includes the following steps: S1: adding the A site material and the B site material to an organic mixed solvent respectively, then heating to 110-140°C, and stirring evenly at a speed of 60-80rpm to obtain an A site material solution and a B site material solution; S2: adding a size control agent to the A site material solution and the B site material solution respectively, and adding aluminum nitrate to the A site material solution and stirring completely, and adding terephthalic acid and hydrofluoric acid to the B site material solution, then maintaining 120-130°C and adding the B site material solution dropwise to the A site material solution, the dropping time is 30-40min, and then stirring at 60-80rpm to keep the reaction warm; S3: waiting for the reaction to have no color change When obvious precipitation is generated after standing, it is naturally cooled to room temperature, the product is centrifuged and filtered out, and washed with ethanol for 2 to 3 times to obtain pretreated particles; S4: the pretreated particles are mixed with the added particles, organic acid anhydride and coupling agent, added to deionized water, heated to 60 to 65°C, kept warm for 2.5 to 3 hours, and then transferred to a high-temperature reactor, the pressure is controlled to 2 to 2.2 MPa, the temperature is raised to 190 to 210°C, and the stirring speed is 120 to 160 rpm to keep warm for 16 to 19 hours. After the reaction is completed, it is naturally cooled to 60 to 70°C and triethanolamine is added to adjust the pH to 9.5 to 10, and ethyl orthosilicate and isopropyl alcohol are added. The reaction is kept warm for 2 to 3 hours. After completion, the product is centrifuged and filtered, washed with ethanol for 2 to 3 times, and vacuum-dried at 70 to 80°C to obtain.

[0006] As a preferred solution, the A site material is at least one of CsBr, RbBr, MAI, and FAI.

[0007] As a preferred solution, the A site material is CsBr or RbBr.

[0008] As a preferred solution, the A site material is CsBr.

[0009] As a preferred solution, the B site material is at least one of PbBr2, SnBr2, and GeBr4.

[0010] As a preferred solution, the B site material is PbBr2 or SnBr2.

[0011] As a preferred solution, the B site material is PbBr2.

[0012] As a preferred solution, the mass ratio of the A site material to the B site material is (2.5-4):(5-7).

[0013] As a preferred solution, the mass ratio of the A site material to the B site material is (2.5-3.5): (5.5-6.5).

[0014] As a preferred solution, the organic mixed solvent is a combination of oleylamine and n-octylamine.

[0015] As a preferred solution, the mass ratio of oleylamine to n-octylamine is (1.5-2.5):(1-1.4).

[0016] As a preferred solution, the mass ratio of oleylamine to n-octylamine is (1.6-2.2): (1.2-1.4).

[0017] As a preferred solution, the size control agent is oleic acid.

[0018] As a preferred solution, the mass ratio of the A site material to the size control agent is (2.5-4): (40-50).

[0019] As a preferred solution, the mass ratio of the B site material to the size control agent is (5-7): (40-50).

[0020] As a preferred solution, the mass ratio of the A site material to aluminum nitrate is (2.5-4): (2-2.5).

[0021] As a preferred solution, the mass ratio of the A site material to aluminum nitrate is (2.5-3.5): (2.1-2.3).

[0022] As a preferred solution, the mass ratio of the B-site material, terephthalic acid and hydrofluoric acid is (5-7): (3-3.8): (12-20).

[0023] As a preferred solution, the mass ratio of the B-site material, terephthalic acid and hydrofluoric acid is (5.5-6.5): (3.2-3.4): (14-16).

[0024] As a preferred solution, the average particle size of the pretreated particles is 120 to 200 nm.

[0025] In the present application, by controlling the compounding ratio of raw materials such as aluminum nitrate and terephthalic acid, the framework particles formed in the initial stage are successfully controlled and added during the formation of microcrystalline materials, and the bonding force therebetween is greatly improved, thereby effectively improving the stability of microcrystalline materials under illumination, high temperature and high humidity environments, and effectively reducing the formation of microcrystalline defects and avoiding decomposition. The terephthalic acid raw material added in the present application can, in the microcrystalline bonding process, rely on the reactivity at the same temperature to preferentially form framework particles with an initial structure, and the formation of framework particles can become a carrier platform for the formation of microcrystalline particles, and in the process of formation, a semi-encapsulated structure of microcrystalline and framework particles is formed by the initial liquid coating effect, thereby significantly reducing the self-defectiveness of microcrystalline materials by the structure of regular framework particles, and by the addition of subsequent added particles, a composite structure with more stability is formed, and a longer electronic path is formed, and the band gap is reduced by the aggregation effect of electrons and holes, thereby obtaining better and excellent light resistance and the formed framework particles can form a more excellent composite particle low surface energy structure by its flat surface, thereby having excellent moisture resistance in a high humidity environment.

[0026] As a preferred solution, the mass ratio of the pretreated particles, the added particles, the organic acid anhydride and the coupling agent is (3-4): (0.6-1): (0.3-0.5): (0.1-0.15).

[0027] As a preferred solution, the mass ratio of the pretreated particles, the added particles, the organic anhydride and the coupling agent is (3.4-3.8): (0.8-1): (0.4-0.45): (0.12-0.14).

[0028] As a preferred solution, the mass ratio of the pretreated particles, ethyl orthosilicate and isopropyl alcohol is (3-4): (0.2-0.5): (0.05-0.1).

[0029] As a preferred solution, the mass ratio of the pretreated particles, tetraethyl orthosilicate and isopropyl alcohol is (3.4-3.8): (0.35-0.45): (0.06-0.08).

[0030] As a preferred solution, the added particles are any one of zinc oxide, titanium dioxide, and antimony dioxide.

[0031] As a preferred solution, the added particles are zinc oxide or titanium dioxide.

[0032] As a preferred solution, the average particle size of the added particles is 5 to 15 nm.

[0033] As a preferred solution, the organic acid anhydride is succinic anhydride or glutaric anhydride.

[0034] As a preferred solution, the coupling agent is a titanate coupling agent or a silane coupling agent.

[0035] As a preferred solution, the average particle size of the perovskite-based microcrystalline material is 460 to 580 nm.

[0036] In this application, by further selecting added particles and controlling their particle size, the comprehensive performance of the perovskite-based microcrystalline material is greatly improved, and its own stability is effectively improved and defects are improved. The added small-particle-sized added particles (such as titanium dioxide and zinc oxide) can be modified by carboxylation on their surface, greatly increasing the coordination binding effect with the internal framework particles, thereby stabilizing the binding stability of the added particles on the surface of the framework particles, and forming an external package for the framework particles to a certain extent. This package effect can further increase the binding strength of the framework particles for the microcrystalline particles, thereby maintaining excellent binding force during long-term use, and preventing the intrusion of water molecules by the framework particles, maintaining the overall composite structure's resistance to water molecules, and obtaining good stability.

[0037] The second aspect of the present application provides an application of the perovskite-based microcrystalline material prepared by the above-mentioned preparation process of the perovskite-based microcrystalline material in the fields of solar cells, sensors, electronic products, and photocatalysis.

[0038] This application has the following beneficial effects:

[0039] 1. The perovskite-based microcrystalline material provided in this application can effectively overcome the internal defects in the material, thereby avoiding the loss of photoelectric performance, and can ensure that the perovskite material has excellent stability under long-term light, high temperature and humidity environments, and still maintains good self-properties in high humidity environments, avoiding decomposition, and thus has very excellent application value.

[0040] 2. A perovskite-based microcrystalline material provided in the present application, in which the added terephthalic acid raw material can preferentially form framework particles with an initial structure during the microcrystal bonding process by relying on the reaction activity at the same temperature, and the formation of the framework particles can become a carrier platform for the formation of microcrystalline particles, and in the formation process, a semi-encapsulated structure of microcrystals and framework particles is formed by the initial liquid coating effect, thereby greatly reducing the inherent defects of the microcrystalline material through the regular structure of the framework particles, and through the subsequent addition of particles, a more stable composite structure is formed, and a longer electron path is formed, and the band gap is reduced by the aggregation effect of electrons and holes, thereby obtaining better light resistance, and the formed framework particles can form a better composite particle low surface energy structure through their flat surface, thereby having excellent moisture resistance in a high humidity environment.

[0041] 3. A perovskite-based microcrystalline material provided in the present application greatly improves the comprehensive performance of the obtained perovskite-based microcrystalline material by selecting added particles and controlling their particle size, and effectively improves its own stability and improves defects; the added small-particle-sized added particles (such as titanium dioxide and zinc oxide) can greatly increase their coordination and binding effect with the internal framework particles through carboxyl modification of their surfaces, thereby stabilizing the binding stability of the added particles on the surface of the framework particles, and forming an external wrapping of the framework particles to a certain extent. This wrapping effect can further increase the binding strength of the framework particles to the microcrystalline particles, thereby maintaining excellent binding force during long-term use, and blocking the invasion of water molecules through the framework particles, maintaining the overall composite structure's resistance to water molecules, and obtaining good stability. DETAILED DESCRIPTION

[0042] The following text further illustrates and demonstrates the technical solutions described in the above-mentioned summary of the invention in the form of specific implementation plans. The following examples are merely practical examples used to illustrate and explain the technical solutions in the specification and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the summary of the invention in this application should be included in the scope of protection to be protected by this application.

[0043] In the following examples, unless otherwise specified, the raw materials are all commercially available products or can be prepared by methods well known to those skilled in the art.

[0044] Example 1

[0045] Example 1 The first aspect provides a preparation process for a perovskite-based microcrystalline material, which specifically includes the following steps, in parts by mass: S1: adding 2.92 parts of A site material and 6.15 parts of B site material to 320 parts of an organic mixed solvent, respectively, and then heating to 125°C and stirring at 80 rpm to obtain an A site material solution and a B site material solution; S2: adding 42.5 parts and 44.8 parts of a size control agent to the A site material solution and the B site material solution, respectively, and adding 2.2 parts of aluminum nitrate to the A site material solution and stirring completely, and adding 3.4 parts of terephthalic acid and 14.8 parts of hydrofluoric acid to the B site material solution, and then adding the B site material solution dropwise to the A site material solution at 130°C, the dropping time is 40 minutes, and then stirring at 80 rpm to keep the reaction warm; S3 : When there is no color change in the reaction and obvious precipitation is generated after standing, it is naturally cooled to room temperature, the product is centrifuged and filtered out, and washed with ethanol three times to obtain pretreated particles; S4: 3.6 parts of pretreated particles are mixed with 0.82 parts of added particles, 0.44 parts of organic acid anhydride and 0.12 parts of coupling agent and added to 150 parts of deionized water, heated to 65°C, kept warm for 3 hours, and then transferred to a high-temperature reactor, the pressure is controlled to 2.1MPa, heated to 200°C, stirred at 140rpm and kept warm for 18 hours, after the reaction is completed, it is naturally cooled to 65°C and triethanolamine is added to adjust the pH to 9.8, 0.38 parts of ethyl orthosilicate and 0.08 parts of isopropyl alcohol are added, and the reaction is kept warm for 2 hours. After completion, the product is centrifuged and filtered, washed with ethanol three times, and vacuum dried at 70-80°C to obtain.

[0046] The A-site material is CsBr; the B-site material is PbBr2.

[0047] The organic mixed solvent is a composition of oleylamine and n-octylamine, and the mass ratio of the two is 1.8:1.2.

[0048] The size control agent is oleic acid.

[0049] The average particle size of the pretreated particles was 148 nm.

[0050] The added particles are titanium dioxide with an average particle size of 10 nm.

[0051] The organic acid anhydride is succinic anhydride, and the silane coupling agent is 3-aminopropyltriethoxysilane.

[0052] The average particle size of the perovskite-based microcrystalline material is 527 nm.

[0053] Example 2

[0054] Example 2 The first aspect provides a preparation process for a perovskite-based microcrystalline material, which specifically includes the following steps, in parts by mass: S1: 3.14 parts of A site material and 5.76 parts of B site material are respectively added to 330 parts of an organic mixed solvent, and then the temperature is raised to 125°C and stirred at 80 rpm to obtain an A site material solution and a B site material solution; S2: 44.2 parts and 43.5 parts of size control agents are added to the A site material solution and the B site material solution, respectively, and 2.3 parts of aluminum nitrate are added to the A site material solution and stirred completely, and 3.4 parts of terephthalic acid and 15.5 parts of hydrofluoric acid are added to the B site material solution, and then the B site material solution is added dropwise to the A site material solution at 130°C, and the addition time is 40 minutes, and then the reaction is stirred at 80 rpm for insulation; S3 : When there is no color change in the reaction and obvious precipitation is generated after standing, it is naturally cooled to room temperature, the product is centrifuged and filtered out, and washed with ethanol three times to obtain pretreated particles; S4: 3.6 parts of pretreated particles are mixed with 0.82 parts of added particles, 0.44 parts of organic acid anhydride and 0.12 parts of coupling agent and added to 150 parts of deionized water, heated to 65°C, kept warm for 3 hours, and then transferred to a high-temperature reactor, the pressure is controlled to 2.1MPa, heated to 200°C, stirred at 140rpm and kept warm for 18 hours, after the reaction is completed, it is naturally cooled to 65°C and triethanolamine is added to adjust the pH to 9.8, 0.38 parts of ethyl orthosilicate and 0.08 parts of isopropyl alcohol are added, and the reaction is kept warm for 2 hours. After completion, the product is centrifuged and filtered, washed with ethanol three times, and vacuum dried at 70-80°C to obtain.

[0055] The A-site material is RbBr; the B-site material is SnBr2.

[0056] The organic mixed solvent is a composition of oleylamine and n-octylamine, and the mass ratio of the two is 1.8:1.2.

[0057] The size control agent is oleic acid.

[0058] The average particle size of the pretreated particles was 166 nm.

[0059] The added particles are titanium dioxide with an average particle size of 10 nm.

[0060] The organic acid anhydride is succinic anhydride, and the silane coupling agent is 3-aminopropyltriethoxysilane.

[0061] The average particle size of the perovskite-based microcrystalline material is 561 nm.

[0062] Comparative Example 1

[0063] The specific implementation method of this comparative example is basically the same as that of Example 1, with the only difference being: S1: 1.55 parts of site A material and 8.55 parts of site B material are respectively added to 320 parts of an organic mixed solvent, then the temperature is raised to 125°C, and stirred evenly at a speed of 80 rpm to obtain site A material solution and site B material solution.

[0064] The average particle size of the perovskite-based microcrystalline material is 322 nm.

[0065] Comparative Example 2

[0066] The specific implementation method of this comparative example is basically the same as that of Example 1, with the only difference being: S1: 5.8 parts of site A material and 3.55 parts of site B material are respectively added to 320 parts of an organic mixed solvent, then the temperature is raised to 125°C, and stirred evenly at a speed of 80 rpm to obtain site A material solution and site B material solution.

[0067] The average particle size of the perovskite-based microcrystalline material is 351 nm.

[0068] Comparative Example 3

[0069] The specific implementation of this comparative example is basically the same as that of Example 1, with the only difference being that: S2: 22.5 parts and 15.5 parts of size control agents were added to the A site material solution and the B site material solution, respectively, and 4.5 parts of aluminum nitrate were added to the A site material solution and stirred thoroughly, and 6.8 parts of terephthalic acid and 25 parts of hydrofluoric acid were added to the B site material solution. Then, the B site material solution was added dropwise to the A site material solution while maintaining 130°C for 50 minutes, and then the reaction was stirred at 80 rpm for insulation.

[0070] The average particle size of the perovskite-based microcrystalline material is 687 nm.

[0071] Comparative Example 4

[0072] The specific implementation method of this comparative example is basically the same as that of Example 1, with the only difference being: S2: 44.2 parts and 43.5 parts of size control agents were added to the A site material solution and the B site material solution, respectively, and 0.9 parts of aluminum nitrate was added to the A site material solution and stirred thoroughly, and 1.9 parts of terephthalic acid and 6.5 parts of hydrofluoric acid were added to the B site material solution, and then the B site material solution was added dropwise to the A site material solution while maintaining 130°C for 40 minutes, and then stirred at 80 rpm for insulation reaction.

[0073] The average particle size of the perovskite-based microcrystalline material is 359 nm.

[0074] Comparative Example 5

[0075] The specific implementation of this comparative example is basically the same as that of Example 1, except that: S4: 3.6 parts of pretreated particles, 0.35 parts of added particles, 0.25 parts of organic acid anhydride and 0.04 parts of coupling agent are mixed and added to 120 parts of deionized water, the temperature is raised to 65°C, and the mixture is kept warm for 3 hours. The mixture is then transferred to a high-temperature reactor, the pressure is controlled to be 2.1 MPa, the temperature is raised to 200°C, and the mixture is kept warm for 18 hours at a speed of 140 rpm. After the reaction is completed, the mixture is naturally cooled to 65°C and triethanolamine is added to adjust the pH to 9.8. 0.38 parts of ethyl orthosilicate and 0.08 parts of isopropyl alcohol are added and the mixture is kept warm for 2 hours. After completion, the product is centrifuged and filtered, washed with ethanol three times, and dried in a vacuum oven at 70-80°C.

[0076] The average particle size of the perovskite-based microcrystalline material is 405 nm.

[0077] Comparative Example 6

[0078] The specific implementation of this comparative example is basically the same as that of Example 1, except that the average particle size of titanium dioxide is 25 nm.

[0079] The average particle size of the perovskite-based microcrystalline material is 677 nm.

[0080] Performance evaluation

[0081] High temperature and high humidity stability: Samples of the microcrystalline materials prepared in the examples and comparative examples were placed in a constant temperature and humidity chamber at 85±3°C and 75±3% relative humidity and stably stored for 6 months. After 6 months, the samples were taken out and observed to see if there was any cracking, powdering, hydrolysis or oxidation. If so, they were marked as unqualified, otherwise they were qualified. 50 samples were tested in each group, and the qualified rate was recorded in Table 1.

[0082] Light stability: Samples of the microcrystalline materials prepared in the examples and comparative examples were placed in a light box to simulate constant sunlight illumination, ensuring a relative humidity of 50±3%. They were stably stored for 3 months. After 6 months, the samples were taken out and observed to see if there was any etching, yellowing, or oxidation. If there was any, it was recorded as unqualified, otherwise it was qualified. 50 samples were tested in each group, and the qualified rate was recorded in Table 1.

[0083] Excitation light test: The microcrystalline materials prepared in the examples and comparative examples were excited by 365 nm light, and the emitted light was green light. The luminescence peak (nm) was detected and determined. The test value was the average of 10 tests and recorded in Table 1.

[0084] Table 1 Performance test results

[0085]

[0086] It can be seen from the examples and comparative examples of the present application and the data results in Table 1 that Examples 1 and 2 of the present application have obvious advantages over comparative examples 1 to 6 in terms of high-temperature and high-humidity stability, light resistance stability, and photoelectric performance. This is mainly due to the combined effect of the framework particle structure and added particles and other matching schemes specified in the present application. Comparative examples 1 to 6 did not adopt the technical solution specified in the present application, resulting in obvious disadvantages in the above-mentioned performance tests. This further proves the necessity of the technical solution specified in the present application for the technical effect of the present application and solving technical problems.

Claims

1. A process for preparing a perovskite-based microcrystalline material, characterized in that: The specific steps include: S1: Add the A site material and the B site material to an organic mixed solvent respectively, then heat it to 110-140°C, and stir it evenly at 60-80 rpm to obtain an A site material solution and a B site material solution; S2: Add a size control agent to the A site material solution and the B site material solution respectively, and add aluminum nitrate to the A site material solution and stir it thoroughly, and add terephthalic acid and hydrofluoric acid to the B site material solution, then maintain 120-130°C and add the B site material solution dropwise to the A site material solution for 30-40 minutes, then stir and keep warm at 60-80 rpm for reaction; S3: When there is no color change in the reaction and obvious precipitation is generated after standing, cool it naturally to room temperature, remove the product by centrifugation, and wash it with ethanol for 2-3 times to obtain pretreated particles; S4: The pretreated particles, the added particles, the organic acid anhydride and the coupling agent are mixed and added to deionized water, the temperature is raised to 60-65°C, the reaction is kept warm for 2.5-3 hours, and then the mixture is transferred to a high-temperature reactor, the pressure is controlled at 2-2.2 MPa, the temperature is raised to 190-210°C, and the reaction is kept warm at 120-160 rpm for 16-19 hours. After the reaction is completed, the mixture is naturally cooled to 60-70°C and triethanolamine is added to adjust the pH to 9.5-10. TEOS and isopropyl alcohol are added and the reaction is kept warm for 2-3 hours. After completion, the product is centrifuged and filtered, washed with ethanol for 2-3 times, and dried in a vacuum oven at 70-80°C to obtain the product. The A site material is at least one of CsBr, RbBr, MAI, and FAI; The B site material is at least one of PbBr2, SnBr2, and GeBr4; The mass ratio of the A site material to the B site material is (2.5-4): (5-7); The organic mixed solvent is a combination of oleylamine and n-octylamine; The mass ratio of the A site material and aluminum nitrate is (2.5-4): (2-2.5); the mass ratio of the B site material, terephthalic acid and hydrofluoric acid is (5-7): (3-3.8): (12-20); The average particle size of the pretreated particles is 120-200 nm; The mass ratio of the pretreated particles, the added particles, the organic acid anhydride and the coupling agent is (3-4): (0.6-1): (0.3-0.5): (0.1-0.15); The mass ratio of oleylamine to n-octylamine is (1.5-2.5): (1-1.4); The size control agent is oleic acid; The mass ratio of the A site material and the size control agent is (2.5-4): (40-50); the mass ratio of the B site material and the size control agent is (5-7): (40-50); The mass ratio of the pretreated particles, ethyl orthosilicate and isopropyl alcohol is (3-4): (0.2-0.5): (0.05-0.1); The added particles are zinc oxide or titanium dioxide; and the average particle size of the added particles is 5-15 nm.

2. Application of the perovskite-based microcrystalline material prepared by the preparation process of the perovskite-based microcrystalline material according to claim 1 in the fields of solar cells, sensors, electronic products, and photocatalysis.

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