Organic-inorganic hybrid perovskite microcrystal and preparation method and application thereof

Abstract

The invention provides an organic-inorganic hybrid perovskite microcrystal as well as a preparation method and application thereof, and relates to the technical field of crystal synthesis. The preparation method comprises the following steps: mixing lead bromide, methylamine hydrobromic acid / cesium bromide and phenylethylamine hydrobromic acid / amphetamine bromide in a set molar ratio according to a metering number, adding two mutually soluble benign solvents, and dissolving to obtain an organic-inorganic hybrid perovskite precursor solution; and coating the organic-inorganic hybrid perovskite precursor solution on a substrate, then exposing the substrate in an anti-solvent atmosphere, and crystallizing to obtain the organic-inorganic hybrid perovskite microcrystal. The obtained micron crystal has the structural characteristics of two-dimensional perovskite, single-phase quasi-two-dimensional perovskite and three-dimensional perovskite at the same time. The crystal can give full play to the advantages and characteristics of different-dimension perovskite, such as high stability of two-dimensional perovskite, adjustability of light-emitting wavelength of quasi-two-dimensional perovskite, high-efficiency photoelectric conversion capability of three-dimensional perovskite, and the like at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of crystal synthesis, and particularly relates to an organic-inorganic hybrid perovskite microcrystal, a preparation method thereof, and an application thereof. Background Art

[0002] Disclosing the information of this background art section is only intended to enhance the overall understanding of the present invention, and is not necessarily regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] Organic-inorganic hybrid perovskite materials integrate the characteristics of organic materials and inorganic materials at the molecular scale and have excellent optoelectronic properties such as simple preparation methods, high carrier mobility, and adjustable emission wavelengths. They are widely used in optoelectronic devices such as solar cells, photodetectors, and light-emitting diodes. In particular, the power conversion efficiency (PCE) of solar cells based on three-dimensional organic-inorganic hybrid perovskites has reached 26.7% in more than a decade. However, the organic components in three-dimensional organic-inorganic perovskite materials are extremely unstable in humid air and are prone to decomposition, which severely restricts the further development and practical application of this material.

[0004] Two-dimensional and single-phase quasi-two-dimensional perovskite materials have more organic hydrophobic groups, so they have higher air stability compared with three-dimensional perovskite materials. However, due to the influence of quantum confinement effect and dielectric confinement effect, two-dimensional and single-phase quasi-two-dimensional perovskites have relatively large exciton binding energies. The relatively large exciton binding energy is not conducive to the dissociation of excitons, which to a certain extent restricts their application in fields such as photodetectors. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an organic-inorganic hybrid perovskite microcrystal, a preparation method thereof, and an application thereof, and to develop microcrystals containing the characteristics of two-dimensional, single-phase quasi-two-dimensional, and three-dimensional perovskites. These microcrystals can not only retain the advantages of good air stability of two-dimensional perovskites, etc., but also retain the advantages of adjustable emission peak positions of quasi-two-dimensional perovskites and good light detection performance of three-dimensional perovskites.

[0006] In order to achieve the above purpose, the present invention is realized through the following technical solutions:

[0007] In the first aspect, a preparation method of an organic-inorganic hybrid perovskite microcrystal, the steps include:

[0008] S1. According to the stoichiometric numbers in the general formula of the organic-inorganic hybrid perovskite, mix one of lead bromide PbBr2, methylammonium hydrobromide MABr, and cesium bromide CsBr, and one of phenethylammonium hydrobromide PEABr and phenylpropylammonium bromide PhPABr, a total of three components, and then add two mutually soluble benign solvents to dissolve and obtain an organic-inorganic hybrid perovskite precursor solution;

[0009] S2. Coat the organic-inorganic hybrid perovskite precursor solution on a substrate, and then expose it to an antisolvent atmosphere to crystallize and obtain organic-inorganic hybrid perovskite microcrystals;

[0010] The general formula of the organic-inorganic hybrid perovskite is A2B n-1 Pb n Br 3n+1 , ∞>n>1, where A + is cesium cation Cs + or methylammonium cation MA + , B + is phenethylammonium cation PEA + or phenylpropylammonium cation PhPA + .

[0011] Second, the organic-inorganic hybrid perovskite microcrystals prepared by the above method for preparing organic-inorganic hybrid perovskite microcrystals simultaneously have the structural characteristics of two-dimensional perovskite, single-phase quasi-two-dimensional perovskite, and three-dimensional perovskite.

[0012] Third, the application of the above organic-inorganic hybrid perovskite microcrystals in the optoelectronic field.

[0013] The beneficial effects of the present invention are as follows:

[0014] 1. The present invention configures a precursor solution based on the molar ratio required for quasi-two-dimensional perovskite crystals, places the precursor solution in an antisolvent atmosphere, allows the antisolvent to diffuse into the precursor solution to initiate perovskite crystallization, and utilizes the different properties such as solubility and volatility of the two solvents to ensure the formation of perovskites with different dimensions such as two-dimensional and quasi-two-dimensional, thereby obtaining organic-inorganic hybrid perovskite microcrystals with the characteristics of two-dimensional, single-phase quasi-two-dimensional, and three-dimensional during the crystallization process. Such crystals can simultaneously give full play to the advantages of different-dimensional perovskites, such as the high stability of two-dimensional perovskite, the tunability of the emission wavelength of quasi-two-dimensional perovskite, and the high-efficiency optoelectronic conversion ability of three-dimensional perovskite, and make up for the deficiencies of organic-inorganic hybrid perovskites with only single-dimensional characteristics.

[0015] 2. The present invention can regulate the composition ratio of perovskites with different dimensions in the obtained perovskite crystals by adjusting the molar ratio of the precursor materials in the precursor solution. This flexibility enables researchers to prepare materials with specific optoelectronic properties according to needs to meet the specific requirements of different application fields such as solar cells and photodetectors. During the preparation process, there is no need for complex synthesis steps or expensive equipment investment. Therefore, this method has high economic efficiency and practicability, providing strong technical support for the wide application of perovskite-based optoelectronic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings forming a part of this invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0017] Figure 1 It is the microscopic image of the organic-inorganic hybrid perovskite microcrystals prepared in Example 1, wherein, (a) is the optical microscopic image and (b) is the fluorescence microscopic image.

[0018] Figure 2 It is the photoluminescence (PL) spectrum of the organic-inorganic hybrid perovskite microcrystals prepared in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0021] In the following detailed description, the reagents used include:

[0022] Methylammonium hydrobromide (MABr), also known as methylammonium hydrobromate and methylammonium bromide, CAS No.: 6876-37-5.

[0023] Phenethylammonium hydrobromide (PEABr), also known as phenethylammonium bromide, CAS No.: 53916-94-2.

[0024] Phenylpropylammonium bromide (PhPABr), also known as phenylpropylammonium bromide, CAS No.: 120375-53-3.

[0025] γ-butyrolactone, also known as 1,4-butyrolactone, CAS No.: 96-48-0.

[0026] Dimethyl sulfoxide (DMSO), also known as dimethyl sulfoxide, CAS No.: 67-68-5.

[0027] N,N-dimethylformamide, CAS No.: 68-12-2.

[0028] A method for preparing an organic-inorganic hybrid perovskite microcrystal, the steps including:

[0029] S1. According to the stoichiometric numbers in the general formula A2BPbBr of the organic-inorganic hybrid perovskite, lead bromide PbBr2, methylammonium hydrobromide MABr (or cesium bromide CsBr), and phenethylammonium hydrobromide PEABr (or phenylpropylamine bromide PhPABr) with a set molar ratio are mixed, and then two mutually soluble benign solvents are added and dissolved to obtain an organic-inorganic hybrid perovskite precursor solution; n-1 Pb n Br 3n+1 In the above, after mixing, two mutually soluble benign solvents are added and dissolved to obtain an organic-inorganic hybrid perovskite precursor solution;

[0030] S2. The organic-inorganic hybrid perovskite precursor solution is coated on a substrate and then exposed to an anti-solvent atmosphere to crystallize and obtain an organic-inorganic hybrid perovskite microcrystal.

[0031] In the above process, an anti-solvent method is used to prepare the organic-inorganic hybrid perovskite microcrystal. The perovskite crystal is precipitated by the mutual evaporation of solvents. By adjusting the molar ratio of the precursor materials in the precursor solution, the dimensional distribution and composition ratio of the obtained perovskite crystal can be regulated, so as to obtain an organic-inorganic hybrid perovskite microcrystal with two-dimensional, single-phase quasi-two-dimensional, and three-dimensional characteristics at the same time.

[0032] Optionally, in S1, two benign solvents are selected. One of them is dimethyl sulfoxide, and the other is selected from any one of γ-butyrolactone, acetonitrile, and N,N-dimethylformamide (DMF); by using the differences in properties such as the volatility and solubility of the two solvents, the precipitation of perovskites with different dimensions is ensured, and then perovskite microcrystals containing two-dimensional, single-phase quasi-two-dimensional, and three-dimensional perovskites are obtained.

[0033] Optionally, in S1, the volume ratio of the two benign solvents is 1:(0.5 - 1.5). By adjusting the volume ratio of the two benign solvents, organic-inorganic hybrid perovskite microcrystals with different composition ratios can be obtained.

[0034] Optionally, in S1, the dissolution method includes: stirring at a rotation speed of 1500 - 2000 r / min for 1 - 2 h using a magnetic stirrer to fully dissolve the crystal powders of one of lead bromide (PbBr2), methylammonium hydrobromide (MABr), and cesium bromide (CsBr), and one of phenethylammonium hydrobromide (PEABr) and phenylpropylammonium bromide (PhPABr), a total of three raw materials, and obtaining a precursor solution.

[0035] Optionally, in S1, the dissolution process is carried out under the temperature condition of 60 - 70 °C to ensure the uniformity and stability of the solution.

[0036] Optionally, in S1, the concentration of the organic-inorganic hybrid perovskite precursor solution is 0.1 - 1 mol / L to obtain micron crystals of different sizes by drop coating.

[0037] Optionally, in S2, the substrate is selected from a glass substrate or an ITO substrate, which is a common substrate for preparing perovskite crystals.

[0038] Optionally, in S2, 10 - 20 μL of the perovskite precursor solution is accurately measured and drop-coated onto the substrate. The larger the volume of the drop-coated perovskite precursor solution, the larger the required substrate. When 10 μL of the perovskite precursor solution is dropped, the area of the required substrate is not less than 1.5×1.5 cm.

[0039] Optionally, in S2, the antisolvent is selected from one of diethyl ether and ethyl acetate. In a semi-sealed environment, the volatilized antisolvent diffuses into the drop-coated perovskite precursor solution, gradually reducing the solubility of the solution, thereby initiating the crystallization of perovskite crystals.

[0040] Optionally, in S2, the crystallization process is carried out under the condition that the temperature is 18 - 22 °C. The temperature control range does not require expensive equipment investment, and it has high economic efficiency and practicality.

[0041] Optionally, in S2, the crystallization time is 22 - 26 h.

[0042] The organic-inorganic hybrid perovskite micron crystals prepared by the above method contain perovskites of different dimensions and simultaneously have the structural characteristics of two-dimensional perovskite, single-phase quasi-two-dimensional perovskite, and three-dimensional perovskite.

[0043] Optionally, the width of the organic-inorganic hybrid perovskite micron crystals is 10 - 90 μm, and the length is 20 - 300 μm.

[0044] This crystal package simultaneously contains the characteristics of two-dimensional, single-phase quasi-two-dimensional, and three-dimensional perovskites, retaining the respective advantages of different dimensions while making up for their respective deficiencies. This ingenious structural design not only enhances the overall stability of the crystal but also enables the obtained micron crystals to exhibit excellent performance in optoelectronic applications; the stability of two-dimensional perovskites ensures the long-term reliability of the device, the tunable emission wavelength of quasi-two-dimensional perovskites provides the possibility for realizing colorful displays and photodetection, and the high-efficiency optoelectronic conversion ability of three-dimensional perovskites significantly improves the performance of optoelectronic devices such as solar cells.

[0045] The applications of the above-mentioned organic-inorganic hybrid perovskite micron crystals in the optoelectronic field include solar cells, light-emitting diodes (LEDs), lasers, photodetectors and photosensors, photocatalysis, image sensors, memory storage, optical communication, etc.

[0046] Example 1

[0047] A method for preparing an organic-inorganic hybrid perovskite micron crystal, comprising the following steps:

[0048] S0. Blow dry the cleaned glass substrate with nitrogen and set it aside for use.

[0049] S1. Take n = 5. According to the stoichiometric numbers in the general formula (PEA)2(MA)4Pb5Br of the organic-inorganic hybrid perovskite, determine the masses of lead bromide PbBr2, methylammonium hydrobromide MABr, and phenethylammonium hydrobromide PEABr according to a molar ratio of 5:4:2, and weigh the powdered raw materials. After mixing the weighed raw materials, add γ-butyrolactone and dimethyl sulfoxide according to a volume ratio of 1:1, and stir and dissolve at a temperature of 70°C and a rotation speed of 1500 r / min for 3 h to prepare an organic-inorganic hybrid perovskite precursor solution with a concentration of 0.2 mol / L. 16 S2. At an environment temperature of 20°C, drop 10 μL of the organic-inorganic hybrid perovskite precursor solution onto the glass substrate, and then place the substrate in a reaction flask. The reaction flask is filled with 1 / 3 of its capacity of diethyl ether, and the glass substrate is set at a certain distance from the diethyl ether liquid surface to form a semi-sealed state, so that the organic-inorganic hybrid perovskite precursor solution is exposed to the anti-solvent atmosphere, promoting the diffusion of the volatilized diethyl ether into the precursor solution, and standing for 24 h to crystallize to obtain the organic-inorganic hybrid perovskite micron crystal.

[0050] S2. At an environment temperature of 20°C, drop 10 μL of the organic-inorganic hybrid perovskite precursor solution onto the glass substrate, and then place the substrate in a reaction flask. The reaction flask is filled with 1 / 3 of its capacity of diethyl ether, and the glass substrate is set at a certain distance from the diethyl ether liquid surface to form a semi-sealed state, so that the organic-inorganic hybrid perovskite precursor solution is exposed to the anti-solvent atmosphere, promoting the diffusion of the volatilized diethyl ether into the precursor solution, and standing for 24 h to crystallize to obtain the organic-inorganic hybrid perovskite micron crystal.

[0051] Example 2

[0052] A method for preparing an organic-inorganic hybrid perovskite micron crystal, which is different from Example 1 in that:

[0053] In S1, take n = 2. According to the stoichiometric numbers in the general formula (PEA)2MAPb2Br7 of the organic-inorganic hybrid perovskite, determine the masses of lead bromide PbBr2, methylammonium hydrobromide MABr, and phenethylammonium hydrobromide PEABr according to the molar ratio of 2:1:2 and weigh them. After mixing the weighed raw materials, add γ-butyrolactone and dimethyl sulfoxide according to the volume ratio of 1:0.5 to prepare an organic-inorganic hybrid perovskite precursor solution with a concentration of 0.5 mol / L.

[0054] All other reagents / materials used and the preparation method are the same as those in Example 1.

[0055] Example 3

[0056] A preparation method of organic-inorganic hybrid perovskite microcrystals, which is different from Example 1 in that:

[0057] In S1, take n = 3. According to the stoichiometric numbers in the general formula (PEA)2MA2Pb3Br 10 determine the masses of lead bromide PbBr2, methylammonium hydrobromide MABr, and phenethylammonium hydrobromide PEABr according to the molar ratio of 3:2:2 and weigh them, and prepare an organic-inorganic hybrid perovskite precursor solution with a concentration of 0.3 mol / L.

[0058] All other reagents / materials used and the preparation method are the same as those in Example 1.

[0059] Example 4

[0060] A preparation method of organic-inorganic hybrid perovskite microcrystals, which is different from Example 1 in that:

[0061] In S1, take n = 5. According to the stoichiometric numbers in the general formula (PEA)2Cs4Pb5Br 16 determine the masses of lead bromide PbBr2, cesium bromide CsBr, and phenethylammonium hydrobromide PEABr according to the molar ratio of 5:4:2 and weigh them, and prepare an organic-inorganic hybrid perovskite precursor solution with a concentration of 0.2 mol / L.

[0062] All other reagents / materials used and the preparation method are the same as those in Example 1.

[0063] Example 5

[0064] A preparation method of organic-inorganic hybrid perovskite microcrystals, which is different from Example 1 in that:

[0065] In S1, take n = 5. According to the stoichiometric numbers in the general formula (PhPA)2MA4Pb5Br 16The stoichiometric numbers in it are used to determine the masses of lead bromide PbBr2, methylammonium hydrobromide MABr, and phenylpropylammonium bromide PhPABr according to the molar ratio of 5:4:2, and they are weighed. An organic-inorganic hybrid perovskite precursor solution with a concentration of 0.2 mol / L is prepared.

[0066] All other reagents / materials used and the preparation method are the same as those in Example 1.

[0067] Example 6

[0068] A preparation method of organic-inorganic hybrid perovskite microcrystals, which is different from Example 1 in that:

[0069] In S1, take n = 5. According to the general formula (PhPA)2Cs4Pb5Br of the organic-inorganic hybrid perovskite 16 The stoichiometric numbers in it are used to determine the masses of lead bromide PbBr2, cesium bromide CsBr, and phenylpropylammonium bromide PhPABr according to the molar ratio of 5:4:2, and they are weighed. An organic-inorganic hybrid perovskite precursor solution with a concentration of 0.2 mol / L is prepared.

[0070] All other reagents / materials used and the preparation method are the same as those in Example 1.

[0071] Performance detection

[0072] The organic-inorganic hybrid perovskite microcrystals obtained in Example 1 are detected. The optical micrograph is as shown in Figure 1 (a) in it. It can be seen that the microcrystals are basically long strips of 40×100 μm; the fluorescence micrograph is as shown in Figure 1 (b) in it. It can be seen that the center position of the crystal mainly emits green fluorescence, a small amount of blue light is simultaneously emitted on the upper surface of the material, and other positions mainly emit light blue fluorescence, that is, the same perovskite crystal material emits different colors of light, proving that the crystal contains the characteristics of multiple-dimensional perovskites.

[0073] The photoluminescence spectrum (PL) of the microcrystals obtained in Example 1 is detected, and the results are as shown in Figure 2 It can be seen from it that multiple peaks are emitted, further proving that the crystal prepared in this example is a multifunctional organic-inorganic hybrid perovskite microcrystal containing two-dimensional, single-phase quasi-two-dimensional, and three-dimensional perovskites at the same time. By adjusting the composition of the organic-inorganic hybrid perovskite precursor, the emission peak position can be adjusted. At the same time, by adjusting the molar ratio of the precursor materials, the composition ratio of different-dimensional perovskites can also be adjusted, and thus the emission wavelength of the organic-inorganic hybrid perovskite microcrystals can also be changed.

[0074] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for preparing organic-inorganic hybrid perovskite micron crystals, characterized in that the steps include: S1, according to the general formula A2B of organic-inorganic hybrid perovskite n-1 Pb n Br 3n+1 The stoichiometric number in the mixture is: mixing lead bromide PbBr2, one of methylamine hydrobromide MABr and cesium bromide CsBr, and one of phenylethylamine hydrobromide PEABr and phenylpropylamine bromide PhPABr in a set molar ratio, adding two mutually soluble benign solvents, and dissolving to obtain an organic-inorganic hybrid perovskite precursor solution; S2, applying an organic-inorganic hybrid perovskite precursor solution onto a substrate, and then exposing the substrate to an anti-solvent atmosphere to crystallize and obtain organic-inorganic hybrid perovskite micron crystals; The general formula of the organic-inorganic hybrid perovskite is A2B n-1 Pb n Br 3n+1 ,∞>n>1, where A + Cesium cation Cs + or methylamine cation MA + , B + PEA is a phenylethylamine cation + or amphetamine cation PhPA + .

2. The method for preparing organic-inorganic hybrid perovskite micron crystals according to claim 1, characterized in that: In S1, two benign solvents are selected, one of which is dimethyl sulfoxide, and the other is selected from any one of γ-butyrolactone, acetonitrile, and N,N-dimethylformamide; Optionally, in S1, the volume ratio of the two benign solvents is 1:(0.5-1.5).

3. The method for preparing organic-inorganic hybrid perovskite micron crystals according to claim 1, characterized in that: The dissolution method includes: stirring at a speed of 1500 to 2000 r / min for 1 to 2 hours; Optionally, in S1, the dissolution process is carried out at a temperature of 60 to 70°C.

4. The method for preparing organic-inorganic hybrid perovskite micron crystals according to claim 1, characterized in that: In S1, the concentration of the organic-inorganic hybrid perovskite precursor solution is 0.1 to 1 mol / L.

5. The method for preparing organic-inorganic hybrid perovskite micron crystals according to claim 1, characterized in that: In S2, the substrate is a glass substrate or an ITO substrate.

6. The method for preparing organic-inorganic hybrid perovskite micron crystals according to claim 1, characterized in that: In S2, the anti-solvent is selected from one of diethyl ether and ethyl acetate.

7. The method for preparing organic-inorganic hybrid perovskite micron crystals according to claim 1, characterized in that: In S2, the crystallization process is carried out at a temperature of 18 to 22°C; Optionally, in S2, the crystallization time is 22-26h.

8. An organic-inorganic hybrid perovskite micron crystal prepared by the method for preparing the organic-inorganic hybrid perovskite micron crystal according to any one of claims 1 to 7, characterized in that: It has the structural characteristics of two-dimensional perovskite, single-phase quasi-two-dimensional perovskite and three-dimensional perovskite.

9. The organic-inorganic hybrid perovskite micron crystal according to claim 8, characterized in that: The width is 10 to 90 μm and the length is 20 to 300 μm.

10. A method for preparing the organic-inorganic hybrid perovskite micron crystals as claimed in any one of claims 1 to 7 or use of the organic-inorganic hybrid perovskite micron crystals as claimed in any one of claims 8 to 9 in the field of optoelectronics.

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