阅读说明：本技术 一种常温快速制备钙钛矿晶粒的简易方法 (Simple method for rapidly preparing perovskite crystal grains at normal temperature ) 是由 邓先宇 李天昊 王洋洋 于 2021-07-20 设计创作，主要内容包括：本发明提供一种常温下快速制备钙钛矿微纳晶粒的方法,将这些晶粒用于制备钙钛矿薄膜的前驱体溶液中,可以显著改善器件性能。本发明的方法包括：将原材料按照钙钛矿产物化学计量比混合,经过适宜的溶剂催化,辅以震荡后得到纯相钙钛矿晶粒,将晶粒清洗、干燥而得,用于钙钛矿前驱体溶液中,可以制备高效太阳能电池器件。本方案可用于钙钛矿材料的提纯,得到的钙钛矿材料,其纯度更高,缺陷更少,为制备高性能钙钛矿电子器件奠定了基础。(The invention provides a method for rapidly preparing perovskite micro-nano crystal grains at normal temperature, and the crystal grains are used in a precursor solution for preparing a perovskite film, so that the performance of a device can be obviously improved. The method of the invention comprises the following steps: the method comprises the steps of mixing raw materials according to the stoichiometric ratio of a perovskite product, catalyzing by a proper solvent, obtaining pure-phase perovskite crystal grains with the assistance of vibration, cleaning and drying the crystal grains to obtain the pure-phase perovskite crystal grains, and preparing the pure-phase perovskite crystal grains into a perovskite precursor solution to be used for preparing a high-efficiency solar cell device. The method can be used for purifying the perovskite material, the obtained perovskite material has higher purity and fewer defects, and a foundation is laid for preparing high-performance perovskite electronic devices.)

1. A method for preparing perovskite crystal grains at normal temperature comprises the following steps:

step A: preparing a raw material mixture, wherein the mixture is prepared by weighing and mixing the mass of corresponding raw materials according to the stoichiometric ratio of the generated perovskite material;

and B: the perovskite is prepared by solvent catalysis, and the solvent is an aniline derivative solvent;

and C: and vibrating the raw material mixture and the solvent at normal temperature to accelerate the obtaining of perovskite crystal grains with higher purity and larger grain size.

2. The method for producing perovskite crystalline grains at ordinary temperature as claimed in claim 1, wherein the perovskite material system 3D structure ABX is produced₃Perovskite crystals or 2D structures (A')₂A_n-1B_nX_3n+1Perovskite crystals, wherein A comprises, but is not limited to, methylamine ion (MA)⁺) Formamidine ion (FA)⁺) Or Cs⁺A' includes but is not limited to PEA⁺、BA⁺Or AVA⁺B contains Pb²⁺Or Sn²⁺X comprises I^-、Br^-Or Cl^-One or more of them.

3. The method according to claim 1, wherein the raw material ratio in step A is obtained according to the stoichiometric ratio of perovskite grain generation in step C, such as MAPbI₃Crystal grains with the added material ratio of MAI to PbI₂1: 1; obtaining PEA if necessary₂MA₃Pb₄I₁₃2D crystal grains with the mixture ratio of PEAI to MAI to PbI₂＝2:3:4。

4. The method for preparing perovskite crystal grains at normal temperature as claimed in claim 1, wherein the aniline derivative solvent comprises 2-ethyl aniline, 2-isopropyl aniline and o-methyl aniline, and the solvent is anhydrous grade solvent with molecular sieve, and has purity of more than 99%.

5. The method for preparing perovskite crystalline grains at normal temperature as claimed in claim 1, wherein the solvent catalysis in step B is to add solvent directly into the mixture obtained in step A to promote the reaction of raw materials, so as to obtain the final perovskite product.

6. A method for preparing perovskite crystal grains at normal temperature according to claim 1, characterized in that: the adding amount of the aniline derivative solvent in the step B depends on the adding amount of the solute in the step A, and the concentration of the solution reaches 0.5-2.5 mol/L.

7. A method for preparing perovskite crystal grains at normal temperature according to claim 1, characterized in that: the step B further comprises the following steps: adding solvent and heating properly to promote the growth of crystal grains, wherein the heating temperature is 50-150 ℃.

8. A method for preparing perovskite crystal grains at normal temperature according to claim 1, characterized in that: and C, controlling the oscillation frequency in the step C during the formation of the accelerated crystal grains to be 60-200 r/min.

9. A high purity perovskite thin film characterized by: the perovskite crystal grain obtained by the preparation method of claim 1 is used as a solute, one or two of DMF and DMSO is used as a solvent, and the solution is obtained after spin coating and heat treatment, and the concentration of the perovskite solution is 0.7-1.5 mol/L.

10. A perovskite thin film solar cell device, characterized by: comprising a metal oxide conductive substrate ITO layer/an electron transport layer TiO₂Perovskite layer/hole transport Spiro-OMeTAD layer/metallic conductive silver layer; or a metal oxide conductive substrate ITO, a hole transport layer PEDOT, PSS, a perovskite layer, an electron transport PCBM layer and a metal conductive silver layer which are connected in sequence, wherein the perovskite layer is the perovskite thin film of claim 9.

Technical Field

The invention belongs to the field of preparation and purification of perovskite photoelectric materials, and particularly relates to rapid preparation of high-purity low-defect organic-inorganic hybrid perovskite crystal grains at normal temperature.

Background

Organic and inorganic perovskite materials are attracted attention since 2003 application in thin-film solar cells, and the photoelectric conversion efficiency of solar devices is also increased from 3.8% to 25.5%. However, the purity and the preparation process of the perovskite raw material influence the dissolution of the perovskite raw material in a solvent, and further influence the quality of the perovskite thin film, and the quality of the perovskite thin film directly influences the performance of a perovskite solar cell device.

In addition, a great deal of research shows that the perovskite precursor solution obtained by dissolving the perovskite crystal in the solvent can be used for preparing a perovskite thin film with higher quality, and is beneficial to the improvement of the performance of a solar cell device. Aiming at the problems of raw material solubility and rapid preparation of perovskite crystal grains, the invention prepares pure-phase perovskite crystal grains by using different solvents for catalysis, and the prepared crystal grains can effectively improve the utilization of raw materials and improve the performance of devices.

Disclosure of Invention

The invention aims to provide a novel and simple preparation method for obtaining high-purity perovskite crystal grains at normal temperature, and aims to solve the problems that the existing perovskite raw material is low in purity and the crystal grains are difficult to obtain.

A simple method for rapidly preparing perovskite crystal grains at normal temperature comprises the following steps:

step A: preparing a raw material mixture, wherein the mixture is prepared by weighing and mixing the mass of corresponding raw materials according to the stoichiometric ratio of the generated perovskite material;

and B: the perovskite solvent catalytic preparation is characterized in that the solvent is aniline derivative solvent, and comprises: 2-ethylaniline, 2-isopropylaniline, o-methylaniline, etc.;

and C: and vibrating the raw material mixture and the solvent at normal temperature to accelerate the obtaining of perovskite crystal grains with higher purity and larger grain size.

The normal temperature is usually 10-30 ℃, usually about 25 ℃. The oscillating frequency in the step C is 60-200 r/min.

As a preferable embodiment of the present invention, the perovskite material system 2D structure (A') is formed in the step A₂A_n-1B_nX_3n+1Perovskite crystal or 3D structure ABX₃Perovskite crystals, wherein A comprises, but is not limited to, methylamine ion (MA)⁺) Formamidine ion (FA)⁺) Or Cs⁺A' includes but is not limited to PEA⁺、BA⁺Or AVA⁺B contains Pb²⁺Or Sn²⁺X comprises I^-、Br^-Or Cl^-One or more of them.

As a preferred technical scheme of the invention, the raw material proportioning system in the step A is obtained according to the stoichiometric ratio of the perovskite product, and the perovskite product comprises MAPbBr₃，CsPbBr₃，FASnBr₂I，PEA₂MA₃Pb₄I₁₃And the like.

As a preferred technical scheme of the invention, the solvent catalysis in the step B is to directly add the solvent into the mixture obtained in the step A to promote the reaction of the raw materials, and the concentration reaches 0.5-2.5mol/L (preferably the concentration is 1.0-1.5 mol/L, and the optimal concentration is 1.5mol/L) to obtain the final perovskite product.

As a preferred technical scheme of the invention, the solvent of the aniline derivative in the step B needs to be a molecular sieve anhydrous grade solvent.

As a preferred embodiment of the present invention, the method step B further comprises: adding solvent and heating properly to promote the growth of crystal grains, wherein the heating temperature is 50-150 ℃.

The simple method for preparing the high-purity perovskite crystal grains at low temperature not only can simply and quickly obtain the perovskite crystal grains, but also provides a novel method for purifying the perovskite by solvent catalysis, simplifies the preparation process and improves the efficiency; the application of the perovskite thin film also comprises various perovskite thin films and devices, such as solar cells, photodetectors, light-emitting diodes and the like, which are prepared by obtaining high-purity perovskite raw materials based on the method.

It is another object of the present invention to provide a high quality perovskite thin film having better optoelectronic properties.

The tin-based perovskite thin film is obtained by taking perovskite crystal grains obtained by the preparation method as a solute and taking one or two of DMF and DMSO as a solvent, and spin-coating and thermally treating the mixed solution. The concentration of the perovskite is 0.7-1.5M.

Another object of the present invention is to provide a perovskite thin film based solar cell device, aiming to further improve the conversion efficiency of the solar cell device.

The solar cell device of the tin-based perovskite thin film comprises a metal oxide conductive substrate ITO layer/an electronic transmission layer TiO layer which are connected in sequence₂Perovskite layer/hole transport Spiro-OMeTAD layer/metallic conductive silver layer; or a metal oxide conductive substrate ITO, a hole transport layer PEDOT, PSS, a perovskite layer, an electron transport PCBM layer and a metal conductive silver layer which are connected in sequence, wherein the perovskite layer is composed of the perovskite thin film obtained in the previous step. The solar cell device can obtain better performance.

The advantages of the present invention over the prior art include:

the invention adopts a solvent catalysis method to rapidly obtain perovskite crystals at normal temperature, provides a simpler and more effective method for the purification of perovskite materials and the specific application of perovskite materials, and simultaneously, compared with the conventional method, the raw materials used in the method are more environment-friendly and are also beneficial to the practical production and application.

The perovskite layer obtained by the method is applied to solar cell devices, and better performance can be obtained.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of a method for rapidly preparing perovskite crystal grains at normal temperature according to the invention.

Wherein 11-13 are respectively raw materials required for preparing perovskite crystal grains, and comprise MAI, CsBr, PEAI and PbI₂、SnBr₂Etc.; 14 is a mixture of raw materials weighed according to the stoichiometric ratio of the perovskite product to be prepared, 15 is a 'catalytic' solvent added into the mixed material, 16 is a mixture material added with the solvent and shaken (or vibrated) to promote the perovskite generation, and 17 is a mixture material obtained by removing the solvent around the generated perovskite crystal grains to obtain dry perovskite crystal grains.

FIG. 2 is a MAPbBr prepared by the process of the invention in example 1 of the invention₃And (4) crystal grains.

Wherein FIG. 21 is (MABr + PbBr)₂) MAPbBr produced by mixture under catalysis of solvent 2-ethyl aniline₃An optical photograph of the crystal grain; MAPbBr produced in FIG. 22 line₃SEM photo of the crystalline grain; FIG. 23 MAPbBr produced₃XRD pattern of the grains.

FIG. 3 is a CsPbBr prepared by the method of the present invention in example 2 of the present invention₃And (4) crystal grains.

Wherein the system in FIG. 31 (CsBr + PbBr)₂) CsPbBr produced by mixture under catalysis of solvent 2-isopropyl aniline₃An optical photograph of the crystal grain; FIG. 32 shows CsPbBr produced₃SEM photo of the crystalline grain; FIG. 33 is CsPbBr produced₃XRD pattern of the grains.

FIG. 4 is a graph of FASnBr prepared by the process of the invention in example 3 of the invention₂I crystal grains.

Wherein FIG. 41 is (FAI + SnBr)₂) FASnBr produced by the mixture under the catalysis of solvent o-toluidine₂I, an optical picture of crystal grains; FIG. 42 shows the resulting FASnBr₂XRD pattern of I crystal grain.

FIG. 5 is a PEA prepared by the process of the present invention in example 4 of the present invention₂MA₃Pb₄I₁₃And (4) crystal grains.

Wherein FIG. 51 is (PEAI + MAI + PbI)₂) PEA produced by "catalyzing" the mixture with 2-isopropyl aniline as solvent₂MA₃Pb₄I₁₃An optical photograph of the crystal grain; FIG. 52 is the PEA generated₂MA₃Pb₄I₁₃SEM photo of the crystalline grain; FIG. 53 is the PEA produced₂MA₃Pb₄I₁₃XRD pattern of the grains.

FIG. 6 is based on the preparation of perovskite (MAPbI) using the present invention₃) Solar cell device for preparing perovskite thin film by using crystal grain preparation precursor solution and solar cell device based on directly used raw materials (MAI + PbI)₂，PbI₂Purity: 98%) of the precursor solution prepared in the step of preparing the thin film.

Wherein curve 61 is based on the perovskite (MAPbI) preparation using the present invention₃) Preparing a J-V curve of a solar cell device of the perovskite thin film by using the crystal grain preparation precursor solution; FIG. 62 is based on the direct use of raw materials (MAI + PbI)₂，PbI₂Purity: 98%) of the precursor solution prepared for the preparation of the J-V curve of the device of the thin film.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example 1

Referring to the preparation scheme of FIG. 1, MAPbBr was prepared₃(lead-based organic-inorganic hybrid perovskite) crystal grains: raw materials MABr and PbBr required by perovskite crystal grain preparation₂Weighing according to the molar ratio of 1:1 to obtain a mixture of raw materials; adding a catalytic solvent 2-ethyl aniline into the mixed material to make the solution concentration reach 1.0mol/L, and shaking (or vibrating) the mixed material added with the solvent to promote perovskite MAPbBr at the frequency of 100r/min₃Crystal grains are generated, the solvent around the generated perovskite crystal grains is removed to obtain dry perovskite crystal grains, and SEM and XRD tests are carried out on the crystal grains, and the result is shown in figure 2.

Example 2

Referring to the preparation flow chart of FIG. 1, the prepared CsPbBr₃(lead-based all-inorganic perovskite) crystal particles: raw materials CsBr and PbBr required by perovskite crystal grain preparation₂Weighing according to the molar ratio of 1:1 to obtainA mixture of raw materials; adding 2-isopropyl aniline serving as a 'catalytic' solvent into the mixed material to enable the solution concentration to reach 1.5mol/L, and shaking (or vibrating) the mixed material added with the solvent to promote the perovskite CsPbBr₃Crystal grains are generated, the solvent around the generated perovskite crystal grains is removed to obtain dry perovskite crystal grains, and SEM and XRD tests are carried out on the crystal grains, and the result is shown in figure 3.

Example 3

FASnBr prepared with reference to the preparation scheme of FIG. 1₂I (tin-based organic-inorganic hybrid perovskite) crystal grain: FAI and SnBr which are raw materials required by perovskite crystal grains₂Weighing according to the molar ratio of 1:1 to obtain a mixture of raw materials; adding a catalytic solvent o-toluidine into the mixed material to make the solution concentration reach 1.5mol/L, and shaking (or vibrating, with the frequency of 100r/min) the mixed material added with the solvent to promote the perovskite FASnBr₂I, crystal grain generation, removing the solvent around the generated perovskite crystal grains to obtain dry perovskite crystal grains, and carrying out SEM and XRD tests on the crystal grains, wherein the result is shown in figure 4.

Example 4

Referring to the preparation flow chart of FIG. 1, PEA is prepared₂MA₃Pb₄I₁₃(lead-based two-dimensional perovskite) crystal grains: raw materials PEAI, MAI and PbI required for preparing perovskite crystal grains₂Weighing according to the molar ratio of 2:3:4 to obtain a mixture of raw materials; adding a catalytic solvent 2-ethyl aniline into the mixed material to make the solution concentration reach 1.5mol/L, and shaking (or vibrating, with frequency of 150r/min) the mixed material added with the solvent to promote the perovskite PEA₂MA₃Pb₄I₁₃Crystal grains are generated, the solvent around the generated perovskite crystal grains is removed to obtain dry perovskite crystal grains, and SEM and XRD tests are carried out on the crystal grains, and the result is shown in figure 5.

Example 5

Preparation and testing of solar cell devices:

(1) raw materials MAI and PbI required by perovskite crystal grains are prepared₂Weighing according to the molar ratio of 1:1 to obtain a mixture of raw materials; to the direction ofAdding a catalytic solvent 2-ethyl aniline into the mixed material to make the solution concentration reach 1.0mol/L), shaking (or vibrating) the mixed material added with the solvent to promote perovskite MAPbI₃And (4) crystal grains are generated, and the solvent around the generated perovskite crystal grains is removed to obtain the dry perovskite crystal grains. Organic hydrochloride salts AGCl and MAPbI₃The crystal grains are added into DMF solvent according to the molar ratio of 0.4:1, (MAPbI)₃Concentration 1M), the solution was stirred at 70 ℃ for 12 h. In addition, organic hydrochloride AGCl and PbI are added₂And MAI in a molar ratio of 0.4:1:1 into DMF solvent (PbI)₂Concentration 1M), the solution was stirred at 70 ℃ for 12 h.

(2) Respectively ultrasonically cleaning ITO in acetone, ITO cleaning solution, deionized water and isopropanol for 10min, drying, and then using UV-O₃The washer is used for 30 min. Depositing PEDOT, PSS on the ITO surface by a spin coating process of 3500rpm and 30s, and depositing N₂The mixture is treated in a glove box at 130 ℃ for 1 h.

(3) Dropwise adding the perovskite solution prepared in the step (1) to the surface of PEDOT (PSS), and spin-coating at the rotating speed of 3000rpm for 30s to obtain a perovskite thin film; the film was finally heated on a 90 ℃ heating stage for 5 min.

(4) A thin film of PCBM (15mg/mL) was deposited on the perovskite thin film at 1500rpm for 30s of spin coating. Finally at 10^-4And thermally evaporating a 100nm silver electrode under the vacuum degree of Pa.

(5) And (3) performance testing: after the preparation process is finished, the performance of the organic-inorganic hybrid all-solid-state solar cell is tested, mainly the current density-voltage (J-V) test is carried out, and a curve image measured under standard sunlight AM (1.5G) is shown in fig. 6.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.