Perovskite microcrystal and preparation method and application thereof

Abstract

The invention discloses a perovskite microcrystal and a preparation method and application thereof, and belongs to the technical field of perovskite single crystal preparation. According to the preparation method disclosed by the invention, the precursor mixture is prepared from the raw materials of the propylene carbonate and the target perovskite, and then the black perovskite microcrystals can be directly separated out in the solution through simple ultrasonic treatment, so that the method is simple to operate, a toxic solvent does not need to be added, and a green propylene carbonate solvent is adopted; the harm to the environment and human bodies is small, the problem of environmental pollution is avoided, and large-scale industrial production can be realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of perovskite single crystal preparation, and particularly relates to a perovskite microcrystal and a preparation method and application thereof. BACKGROUND

[0002] Perovskite halide materials have developed rapidly in recent decades, and the certified efficiency of perovskite solar cells has exceeded 26%, and the commercialization process is accelerating. The key to preparing high-efficiency perovskite solar cells is to prepare high-quality perovskite light-absorbing layers. At present, the preparation method of the perovskite light-absorbing layer is mainly to dissolve halide amine, lead iodide and other materials into a solution for preparation. However, the polycrystalline thin film prepared by this method cannot guarantee a strict stoichiometric ratio, and has many defects. When the perovskite single crystal is used as a raw material, it has the advantages of accurate stoichiometric ratio and good uniformity, which is beneficial to reducing the defect density of the final perovskite thin film.

[0003] In addition, the current methods for preparing perovskite single crystals mainly include inverse temperature method and anti-solvent assisted crystallization method. The inverse temperature method is prepared according to the characteristics that the solubility of perovskite in a solvent changes with temperature. This method usually needs to first raise the temperature to more than 100 degrees, and then slowly cool down to make the perovskite crystals precipitate. The disadvantage is that it requires high temperature control, and the crystal growth period is long. The commonly used solvent is gamma-butyrolactone, which is an easily controlled chemical, and is not conducive to large-scale production. The other anti-solvent assisted crystallization method is to slowly permeate anti-solvent vapor into the perovskite solution. This method generally needs tens of hours or more, and the commonly used anti-solvent is mostly chlorobenzene, dichloromethane and other highly toxic solvents. SUMMARY

[0004] The purpose of the present application is to provide a perovskite microcrystal and a preparation method and application thereof, to solve the technical problems of the existing preparation method that the process is complex and pollutes the environment.

[0005] In order to achieve the above purpose, the following technical solutions are adopted in the present application:

[0006] The present application discloses a preparation method of a perovskite microcrystal, comprising the following steps:

[0007] The corresponding raw materials are weighed according to the molar ratio of each raw material of the target perovskite;

[0008] The propylene carbonate and the raw materials are mixed to obtain a precursor mixture;

[0009] The precursor mixture is subjected to ultrasonic treatment to precipitate perovskite microcrystals.

[0010] Further, the chemical structure general formula of the target perovskite is ABX3;

[0011] wherein A is (CH3NH3+ MA + , (HC(NH2)2 + )FA + Cs + At least one of them;

[0012] B is Pb 2+ X is I - ,Br - At least one of Cl-.

[0013] Furthermore, the raw materials include A-site component materials, B-site component materials, and additives.

[0014] Furthermore, the A-site component material is at least one of FAX, MAX, and CsX;

[0015] The B-site component material is PbX2; X is I. - ,Br - and Cl - At least one of them.

[0016] The additive is MACl.

[0017] Furthermore, the molar ratio of MACl to PbI2 is 5%-40%.

[0018] Furthermore, each 1L of precursor mixture contains 1L of propylene carbonate and 0.4-2mol of raw materials.

[0019] Furthermore, the ultrasonic treatment time is 1-60 minutes, and the ultrasonic treatment temperature is 25-60℃.

[0020] The present invention also discloses a perovskite microcrystal prepared by the above method.

[0021] The present invention also discloses the application of the above-mentioned perovskite microcrystals in perovskite solar cells.

[0022] Furthermore, the perovskite microcrystals serve as the material for preparing the perovskite light-absorbing thin film in a perovskite solar cell.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention discloses a method for preparing perovskite microcrystals. A precursor mixture is prepared using propylene carbonate and various raw materials of the target perovskite. Then, black perovskite microcrystals can be directly precipitated in the solution through simple ultrasonic treatment. This method is simple to operate, does not require the addition of toxic solvents, uses propylene carbonate as a green solvent, has little harm to the environment and human body, does not cause environmental pollution problems, and can realize large-scale industrial production.

[0025] Further, the operation is carried out at room temperature, without the need for high temperature and precise temperature control means, short preparation time, convenient and fast, short crystal elongation period, and wide application prospect.

[0026] Further, the present application uses ultrasonic treatment to prepare perovskite microcrystals. Ultrasonic treatment can accelerate the chemical reaction rate in the precursor mixture and promote the rapid precipitation of perovskite microcrystals. This efficient preparation method helps to shorten the production cycle and improve production efficiency. Ultrasonic treatment can also ensure that the precursor mixture is more uniform during precipitation, which helps to reduce crystal agglomeration and uneven particle size distribution, thereby obtaining perovskite microcrystals with uniform size and regular morphology. Compared with traditional heating or solvent evaporation methods, ultrasonic treatment does not require additional heat sources or high-energy-consuming equipment, thus reducing energy consumption to some extent during the preparation process.

[0027] Further, propylene carbonate as a green solvent has relatively low toxicity and is easy to recycle, which helps to reduce the environmental impact of the preparation process. In addition, by optimizing the amount of solvent used and the recovery process, production costs and environmental burden can be further reduced.

[0028] Further, the preparation method can precisely control the composition and structure of perovskite microcrystals by precisely controlling the molar ratio of raw materials and ultrasonic treatment conditions (such as ultrasonic power, time, etc.). This high degree of controllability helps to obtain perovskite microcrystals with specific properties and meet different application requirements.

[0029] The present application also discloses the application of perovskite microcrystals prepared by the above method in perovskite solar cells. When used in perovskite light-absorbing layer films, the perovskite microcrystals have lower defect density and have broad application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0030] Fig. 1 XRD pattern of perovskite microcrystals obtained in Example 1 of the present application;

[0031] Fig. 2 XRD pattern of perovskite microcrystals obtained in Example 2 of the present application;

[0032] Fig. 3 XRD pattern of perovskite microcrystals obtained in Example 3 of the present application;

[0033] Fig. 4 XRD pattern of perovskite microcrystals obtained in Example 4 of the present application. DETAILED DESCRIPTION

[0034] To enable persons skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have their usual meanings to those skilled in the art of the present application, and in the event of conflict, the definitions contained herein shall prevail.

[0035] Theories or mechanisms described and disclosed herein, whether correct or not, should not be considered limiting on the scope of the present application, i.e., the present application can be practiced without regard to any particular theory or mechanism.

[0036] Herein, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, amounts, contents and concentrations, are for the sake of brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0037] Herein, unless otherwise specified, "comprise", "include", "contain", "have" or similar words encompass the meaning of "consist of" and "consist essentially of", for example, "A comprises a" encompasses the meaning of "A comprises a and other" and "A comprises only a".

[0038] Herein, for the sake of brevity, all possible combinations of the various technical features in the various embodiments or examples are not described. Therefore, as long as there is no contradiction in the combination of the technical features, the various technical features in the various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered as the scope of the present specification.

[0039] A first aspect of the present application discloses a method for preparing perovskite microcrystals, comprising the following steps:

[0040] Step 1: The corresponding raw materials are weighed according to the molar ratio of each raw material of the target perovskite;

[0041] Step 2: Propylene carbonate (PC) is added to the raw materials weighed in step 1 to obtain a precursor mixture;

[0042] Step 3: The precursor mixture obtained in step 2 is subjected to ultrasonic treatment to precipitate black perovskite microcrystals in the solution.

[0043] Preferably, in step 1, the chemical structure of the target perovskite has a general formula ABX3;

[0044] Preferably, A is (CH3NH3 + )MA + , (HC(NH2)2 + )FA+ , Cs + , B is Pb2 + , X is I - , Br - , and Cl - .

[0045] Preferably, the perovskite raw material is divided into an A-site component material, a B-site component material, and an additive.

[0046] Preferably, the A-site component material is at least one of FAI, MAI, and CsI.

[0047] Preferably, the B-site component material is PbI2.

[0048] Preferably, the additive is MACl.

[0049] Preferably, the molar ratio of the additive MACl to PbI2 is 5%-40%.

[0050] Preferably, in step 2, the concentration of the precursor mixture is 0.4-2 mol / L.

[0051] Preferably, in step 3, the ultrasonic treatment is performed for 1 minute-60 minutes at a temperature of room temperature 25-60℃.

[0052] The above method is low-temperature and can quickly prepare perovskite microcrystals. Compared with the prior art, propylene carbonate, a green solvent, is used, which has little harm to the environment and the human body; secondly, high temperature and precise temperature control means are not required, the preparation time is short, and the preparation can be completed at room temperature.

[0053] The second aspect of the present application discloses a perovskite single crystal prepared by the above preparation method; ultrasonic treatment helps to form perovskite microcrystals with regular morphology and uniform size during precipitation, and such uniformity is crucial for improving the photoelectric performance and mechanical stability of the material; ultrasonic treatment can accelerate the chemical reaction in the precursor mixture, promote the rapid precipitation of perovskite microcrystals, and help to improve the crystallinity thereof. High crystallinity means that the atomic arrangement inside the material is more ordered and the defect density is lower, thereby being conducive to improving the photoelectric conversion efficiency and carrier mobility of the material.

[0054] The third aspect of the present application discloses the application of the above perovskite microcrystal in a perovskite solar cell.

[0055] Preferably, the perovskite microcrystal is used as a preparation material for a perovskite light-absorbing layer film in a perovskite solar cell, and the perovskite microcrystal has a lower defect state density when used in the perovskite light-absorbing layer film, thereby having a broad application prospect.

[0056] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0057] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0058] Example 1

[0059] A method for preparing perovskite microcrystals includes the following steps:

[0060] Step 1: Using FAPbI3 perovskite as the target perovskite, weigh the corresponding raw materials according to the molar ratio of each raw material of the target perovskite, and weigh 240.80mg FAI, 645.41mg PbI2 and 28.35mg MACl into a container;

[0061] Step 2: Add 1 mL of propylene carbonate to the container to obtain the precursor mixture;

[0062] Step 3: The precursor mixture was sonicated at room temperature for 10 minutes to obtain a black powder. The black powder was washed with ether and then vacuum dried at 60°C for 12 hours to obtain perovskite microcrystals.

[0063] Example 2

[0064] A method for preparing perovskite microcrystals includes the following steps:

[0065] Step 1: Using FA 0.95 Cs 0.05 Using PbI3 perovskite as the target perovskite, the corresponding raw materials were weighed according to the molar ratio of each raw material in the target perovskite, and 228.80 mg FAI, 18.18 mg CsI, 645.41 mg PbI2 and 28.35 mg MACl were weighed into a container.

[0066] Step 2: Add 1 mL of propylene carbonate to the container to obtain the precursor mixture;

[0067] Step 3: The precursor mixture was ultrasonicated at room temperature for 10 minutes to obtain black powder, the black powder was washed with ether, and then dried at 60°C under vacuum for 12 hours to obtain perovskite microcrystals.

[0068] Example 3

[0069] A method for preparing perovskite microcrystals, comprising the following steps:

[0070] Step 1: 2416.72 mg of FAI, 36.37 mg of CsI, 645.41 mg of PbI2, and 28.35 mg of MACl were weighed in a container according to the molar ratio of each raw material of the target perovskite. 0.9 Cs 0.1 PbI3 perovskite as the target perovskite, the corresponding raw materials were weighed according to the molar ratio of each raw material of the target perovskite, 2416.72 mg of FAI, 36.37 mg of CsI, 645.41 mg of PbI2, and 28.35 mg of MACl were weighed in a container;

[0071] Step 2: 1 mL of propylene carbonate was added to the container to obtain a precursor mixture;

[0072] Step 3: The precursor mixture was ultrasonicated at room temperature for 10 minutes to obtain black powder, the black powder was washed with ether, and then dried at 60°C under vacuum for 12 hours to obtain perovskite microcrystals.

[0073] Example 4

[0074] A method for preparing perovskite microcrystals, comprising the following steps:

[0075] Step 1: 2416.72 mg of FAI, 36.37 mg of CsI, 645.41 mg of PbI2, and 28.35 mg of MACl were weighed in a container according to the molar ratio of each raw material of the target perovskite. 0.85 Cs 0.15 PbI3 perovskite as the target perovskite, the corresponding raw materials were weighed according to the molar ratio of each raw material of the target perovskite, 2416.72 mg of FAI, 36.37 mg of CsI, 645.41 mg of PbI2, and 28.35 mg of MACl were weighed in a container;

[0076] Step 2: 1 mL of propylene carbonate was added to the container to obtain a precursor mixture;

[0077] Step 3: The precursor mixture was ultrasonicated at room temperature for 10 minutes to obtain black powder, the black powder was washed with ether, and then dried at 60°C under vacuum for 12 hours to obtain perovskite microcrystals.

[0078] Example 5

[0079] A method for preparing perovskite microcrystals, comprising the following steps:

[0080] Step 1: Take FAPbI3perovskite as the target perovskite, and take the corresponding raw materials according to the molar ratio of each raw material of the target perovskite, and take 240.80 mg of FAI, 645.41 mg of PbI2, and 28.35 mg of MACl in a container;

[0081] Step 2: Add 1 mL of propylene carbonate to the container to obtain a precursor mixture;

[0082] Step 3: Ultrasonic the precursor mixture at room temperature for 20 minutes to obtain a black powder, wash the black powder with diethyl ether, and then dry at 60°C under vacuum for 12 hours to obtain perovskite microcrystals.

[0083] Example 6

[0084] A method for preparing perovskite microcrystals, comprising the following steps:

[0085] Step 1: Take FAPbI3perovskite as the target perovskite, and take the corresponding raw materials according to the molar ratio of each raw material of the target perovskite, and take 240.80 mg of FAI, 645.41 mg of PbI2, and 28.35 mg of MACl in a container; 0.95 Cs 0.05 PbI3perovskite as the target perovskite, and take the corresponding raw materials according to the molar ratio of each raw material of the target perovskite, and take 228.80 mg of FAI, 18.18 mg of CsI, 645.41 mg of PbI2, and 28.35 mg of MACl in a container;

[0086] Step 2: Add 1 mL of propylene carbonate to the container to obtain a precursor mixture;

[0087] Step 3: Ultrasonic the precursor mixture at room temperature for 20 minutes to obtain a black powder, wash the black powder with diethyl ether, and then dry at 60°C under vacuum for 12 hours to obtain perovskite microcrystals.

[0088] Example 7

[0089] A method for preparing perovskite microcrystals, comprising the following steps:

[0090] Step 1: Take FAPbI3perovskite as the target perovskite, and take the corresponding raw materials according to the molar ratio of each raw material of the target perovskite, and take 240.80 mg of FAI, 645.41 mg of PbI2, and 28.35 mg of MACl in a container; 0.9 Cs 0.1 PbI3perovskite as the target perovskite, and take the corresponding raw materials according to the molar ratio of each raw material of the target perovskite, and take 228.80 mg of FAI, 18.18 mg of CsI, 645.41 mg of PbI2, and 28.35 mg of MACl in a container;

[0091] Step 2: Add 1 mL of propylene carbonate to the container to obtain a precursor mixture;

[0092] Step 3: The precursor mixture was ultrasonicated at room temperature for 45 minutes to obtain a black powder, the black powder was washed with ether, and then dried at 60°C under vacuum for 12 hours to obtain perovskite microcrystals.

[0093] Example 8

[0094] A method for preparing perovskite microcrystals, comprising the following steps:

[0095] Step 1: FAPbI3 perovskite was taken as the target perovskite, and the corresponding raw materials were weighed according to the molar ratio of each raw material of the target perovskite, 240.80 mg of FAI and 645.41 mg of PbI2 were weighed in a container; 0.85 Cs 0.15 PbI3 perovskite was taken as the target perovskite, and the corresponding raw materials were weighed according to the molar ratio of each raw material of the target perovskite, 204.68 mg of FAI, 54.56 mg of CsI, 645.41 mg of PbI2, and 28.35 mg of MACI were weighed in a container;

[0096] Step 2: 1 mL of propylene carbonate was added to the container to obtain a precursor mixture;

[0097] Step 3: The precursor mixture was ultrasonicated at room temperature for 60 minutes to obtain a black powder, the black powder was washed with ether, and then dried at 60°C under vacuum for 12 hours to obtain perovskite microcrystals.

[0098] Comparative Example 1

[0099] A method for preparing perovskite microcrystals, comprising the following steps:

[0100] Step 1: FAPbI3 perovskite was taken as the target perovskite, and the corresponding raw materials were weighed according to the molar ratio of each raw material of the target perovskite, 240.80 mg of FAI and 645.41 mg of PbI2 were weighed in a container;

[0101] Step 2: 1 mL of propylene carbonate was added to the container to obtain a precursor mixture;

[0102] Step 3: The precursor mixture was ultrasonicated at room temperature for 10 minutes to obtain perovskite microcrystals.

[0103] Comparative Example 2

[0104] A method for preparing perovskite microcrystals, comprising the following steps:

[0105] Step 1: FAPbI3 perovskite was taken as the target perovskite, and the corresponding raw materials were weighed according to the molar ratio of each raw material of the target perovskite, 240.80 mg of FAI, 645.41 mg of PbI2, and 28.35 mg of MACI were weighed in a container;

[0106] Step 2: 1 mL of γ-butyrolactone was added to the container to obtain a precursor mixture;

[0107] Step 3: The precursor mixture is ultrasonicated for 10 minutes at room temperature, and no perovskite microcrystal is obtained.

[0108] Figs. 1-4 The XRD patterns of the perovskite microcrystals obtained in Examples 1-4, respectively, can be seen from the figures, and it can be seen that the method of the present application can accurately prepare FAPbI3 perovskite, FA 095 Cs 005 PbI3 perovskite, FA 09 Cs 01 PbI3 perovskite and FA 085 Cs 015 PbI3 perovskite, and the obtained microcrystal has high purity and no other impurities; the method of the present application can quickly prepare perovskite microcrystal at low temperature, and can realize industrial production.

[0109] The above content only illustrates the technical idea of the present application, and cannot limit the protection scope of the present application, and any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the claims of the present application.

Claims

1. A method for preparing perovskite microcrystals, characterized in that, Includes the following steps: Weigh the corresponding raw materials according to the molar ratio of each raw material in the target perovskite; Propylene carbonate and raw materials are mixed to obtain a precursor mixture; The precursor mixture was subjected to ultrasonic treatment to precipitate perovskite microcrystals.

2. The method for preparing perovskite microcrystals according to claim 1, characterized in that, The target perovskite has the general chemical structural formula ABX3; Where A is (CH3NH3) + MA + , (HC(NH2)2 + )FA + Cs + At least one of them; B is Pb 2+ X is I - ,Br - and Cl - At least one of them.

3. The method for preparing perovskite microcrystals according to claim 1, characterized in that, The raw materials include A-site component materials, B-site component materials, and additives.

4. The method for preparing perovskite microcrystals according to claim 3, characterized in that, The A-site component material is at least one of FAX, MAX, and CsX; The B-site component material is PbX2; X is I- or Br-. - and Cl - At least one of them; The additive is MACl.

5. The method for preparing perovskite microcrystals according to claim 4, characterized in that, The molar ratio of MACl to PbI2 is 5%-40%.

6. The method for preparing perovskite microcrystals according to claim 1, characterized in that, Each 1L of precursor mixture contains 1L of propylene carbonate and 0.4-2mol of raw materials.

7. The method for preparing perovskite microcrystals according to claim 1, characterized in that, The ultrasonic treatment time is 1-60 minutes, and the ultrasonic treatment temperature is 25-60℃.

8. A perovskite microcrystal, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 7.

9. The application of the perovskite microcrystals according to claim 8 in perovskite solar cells.

10. The application of a perovskite microcrystal according to claim 9 in a perovskite solar cell, characterized in that, The perovskite microcrystals are used as the material for preparing the perovskite light-absorbing thin film in perovskite solar cells.

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