阅读说明：本技术 一种有机-无机杂化铅卤化物钙钛矿纳米晶的制备方法 (Preparation method of organic-inorganic hybrid lead halide perovskite nanocrystalline ) 是由 *** 张玉红 杨丽丽 范琳 孙云飞 于 2019-09-16 设计创作，主要内容包括：本发明提供了一种有机-无机杂化铅卤化物钙钛矿纳米晶的制备方法,本发明的目的是提供一种制备过程简单、可重复性高,能够可控合成不同尺寸有机-无机杂化铅卤化物钙钛矿纳米晶的方法,该方法首先在器皿中装入多元斥溶剂溶液,然后将过滤筛固定在器皿的顶部,最后将整个器皿放在加热基板上进行加热。利用过滤筛的渗透作用,向过滤筛中倒入钙钛矿前驱体溶液和粘合剂的混合液,通过重力沉降,当钙钛矿前驱体溶液与多元斥溶剂溶液接触时生成钙钛矿纳米晶。本发明通过控制过滤筛孔径目数即可很容易的控制纳米晶尺寸。(The invention provides a preparation method of organic-inorganic hybrid lead halide perovskite nanocrystalline, which is simple in preparation process and high in repeatability and can controllably synthesize organic-inorganic hybrid lead halide perovskite nanocrystalline with different sizes. And pouring mixed solution of the perovskite precursor solution and the adhesive into the filter sieve by utilizing the osmosis action of the filter sieve, and generating perovskite nanocrystals when the perovskite precursor solution is in contact with the multi-element solvent repellent solution through gravity settling. The invention can easily control the size of the nanocrystalline by controlling the aperture and mesh number of the filter sieve.)

1. A preparation method of organic-inorganic hybrid lead halide perovskite nanocrystalline is characterized by comprising the following specific steps:

1) preparing a vessel with the length-width-height ratio of 1:1:4, sequentially ultrasonically cleaning the vessel with deionized water, alcohol, acetone and alcohol for 20min, finally drying the vessel, putting a multi-element solvent repellent solution into the vessel, wherein the multi-element solvent repellent solution accounts for three fifths of the whole vessel, and fixing a filter screen on the top of the vessel; the multi-element repellent solvent is formed by mixing a component A and a component B, wherein the component A is 2-3 of chlorobenzene, toluene and isopropanol, the component B is pyridine or chloroform, the solvents in the component A are mixed in an equal volume ratio, and the volume ratio of the component A to the component B is 1: 1;

2) placing the vessel containing multiple solvent repellent solutions on a heating substrate for heating for 15-20 min; the heating temperature of the heating substrate is 65-100 ℃;

3) placing a filter sieve above the vessel, and pouring 5g of organic-inorganic hybrid lead halide perovskite precursor solution with the concentration of 1-2g/mL and 0.5g of mixed solution of adhesive with the concentration of 10g/mL into the filter sieve; the mixed solution of the organic-inorganic hybrid lead halide perovskite precursor solution and the adhesive is slowly dripped into the vessel through the small holes of the stainless steel sample sieve by gravity settling, and when the perovskite precursor solution is contacted with the multi-element solvent repellent solution, organic-inorganic hybrid lead halide perovskite nano crystals are generated and precipitated at the bottom of the vessel.

The organic-inorganic hybrid lead halide precursor solution consists of solute A, solute B and mixed solvent, wherein the solute A is PbI₂、PbCl₂Or PbBr₂Solute B is CH₃NH₃I、CH₃NH₃Cl or CH₃NH₃Br, the molar ratio of solute A to solute B is (0.9-1.1): 1; the mixed solvent is HCON (CH)₃)₂And HCON (CH)₃)₂Mixed solution of (2) HCON (CH) in mixed solvent₃)₂And HCON (CH)₃)₂In a volume ratio of 7: 3; the organic-inorganic hybrid lead halide is CH₃NH₃PbI₃、CH₃NH₃PbCl₃Or CH₃NH₃PbBr₃；

The grain size of the organic-inorganic hybrid lead halide perovskite nano crystal is 0.3-1.5 mu m; the adhesive is PMMA, epoxy butyronitrile or epoxy resin solution.

2. The method for preparing organic-inorganic hybrid lead halide perovskite nano-crystals as claimed in claim 1, wherein the size of the organic-inorganic hybrid lead halide perovskite nano-crystals is controlled by controlling the mesh number of the filter sieve, and the size is smaller when the mesh number is higher.

3. The method for preparing organic-inorganic hybrid lead halide perovskite nanocrystals as claimed in claim 1, wherein the mesh number of the filter sieve is 2800 meshes, 150 meshes or 18 meshes.

4. The preparation method of organic-inorganic hybrid lead halide perovskite nano-crystal according to claim 1, wherein the component A of the multi-component solvent repellent is chlorobenzene and toluene with equal volume.

5. The method for preparing organic-inorganic hybrid lead halide perovskite nanocrystals as claimed in claim 1, wherein the multi-component solvent-repellent B component is pyridine.

6. The method for preparing organic-inorganic hybrid lead halide perovskite nanocrystals as claimed in claim 1, wherein the vessel is made of stainless steel, glass or ceramic.

Technical Field

The invention belongs to the technical field of crystal material preparation processes, and particularly relates to a preparation method of organic-inorganic hybrid lead halide perovskite nanocrystals.

Background

The organic-inorganic hybrid lead halide perovskite material has excellent properties: high absorption coefficient, high bipolar carrier transport capacity for electrons and holes, long and relatively balanced electron and hole diffusion length, low exciton confinement energy, and high molar extinction coefficient; besides the advantages, the perovskite material has adjustable components and rich preparation process of the perovskite active layer, thereby being widely concerned. The nanocrystalline prepared on the basis of the material has wide application prospect in photovoltaic devices, field effect transistors, photoelectric detectors, spin devices and other photoelectric functional devices.

At present, the methods for preparing perovskite nanocrystals are roughly classified into two major categories, namely physical vacuum evaporation and chemical deposition, from the complex conditions of instruments and equipment. The physical vacuum evaporation method takes lead iodide (lead bromide or lead chloride) and methylamine as raw materials, adopts a co-evaporation mode, can obtain high-quality perovskite nanocrystalline with uniform surface and controllable thickness, but needs expensive vacuum equipment and complex preparation process, and is not beneficial to large-area popularization; the chemical deposition method is divided into a one-step spin coating method and a two-step solution method. The one-step spin coating method is a method for dropping an anti-solvent in the spin coating process of a perovskite precursor solution so as to remove the original solvent and separate out the perovskite by rapid crystallization, and has advantages in operation process and processing time. The process of the method is simpler, but the obtained perovskite nanocrystalline has a rough surface and more defects, and the problem of lead residue exists. The two-step solution method first prepares a lead iodide (lead bromide or lead chloride) thin film on a substrate by spin coating, and then converts it into a perovskite thin film by immersion in a solution of methylamine salt or treatment in vapor of methylamine salt or continuous spin coating of methylamine salt solution on top of the thin film, but this conversion method often causes peeling of the perovskite thin film and lead residue, and thus it can be seen that the chemical deposition method is also deficient for preparing high quality perovskite nanocrystals.

At present, many solutions have been proposed for preparing high-quality perovskite nanocrystals, such as optimization of the composition of the perovskite precursor solution, selection of the solvent, annealing conditions, and the like. Despite some efforts, there are still few reports on how to control perovskite grain size and crystallinity, develop a low-cost preparation which is simple and easy to implement and does not require complex equipment, and obtain high-quality perovskite nanocrystals.

Disclosure of Invention

Aiming at the defects and shortcomings in the prior art, the invention aims to provide the preparation method which is simple in preparation process and high in repeatability and can prepare the organic-inorganic hybrid lead halide perovskite nanocrystals with different sizes by controlling the aperture and the mesh number of the filter sieve and utilizing the gravity sedimentation of the perovskite precursor solution.

The preparation method of the organic-inorganic hybrid lead halide perovskite nanocrystalline comprises the steps of firstly filling a multi-element solvent repellent solution into a vessel, then fixing a filter screen at the top of the vessel, and finally placing the whole vessel on a heating substrate for heating. And pouring mixed solution of the perovskite precursor solution and the adhesive into the filter sieve by utilizing the osmosis action of the filter sieve, and generating perovskite nanocrystals when the perovskite precursor solution is in contact with the multi-element solvent repellent solution through gravity settling. The size of the grown perovskite nanocrystal can reach the micron level.

The preparation method comprises the following specific steps:

1) preparing a vessel with the length-width-height ratio of 1:1:4, sequentially ultrasonically cleaning the vessel with deionized water, alcohol, acetone and alcohol for 20min, finally drying the vessel, putting a multi-element solvent repellent solution into the vessel, wherein the multi-element solvent repellent solution accounts for three fifths of the whole vessel, and fixing a filter sieve on the top of the vessel; the multi-element repellent solvent is formed by mixing a component A and a component B, wherein the component A is 2-3 of chlorobenzene, toluene and isopropanol, the component B is pyridine or chloroform, all solvents in the component A are mixed in equal proportion, and the volume ratio of the component A to the component B is 1: 1;

2) placing the vessel containing multiple solvent repellent solutions on a heating substrate for heating for 15-20 min; the heating temperature of the heating substrate is 65-100 ℃;

3) placing a filter sieve above the vessel, and pouring 5g of organic-inorganic hybrid lead halide perovskite precursor solution with the concentration of 1-2g/mL and 0.5g of mixed solution of adhesive with the concentration of 10g/mL into the filter sieve; the mixed solution of the organic-inorganic hybrid lead halide perovskite precursor solution and the adhesive is slowly dripped into the vessel through the small holes of the stainless steel sample sieve by gravity settling, and when the perovskite precursor solution is contacted with the multi-element solvent repellent solution, organic-inorganic hybrid lead halide perovskite nano crystals are generated and precipitated at the bottom of the vessel.

The organic-inorganic hybrid lead halide precursor solution consists of solute A, solute B and mixed solvent, wherein the solute A is PbI₂、PbCl₂Or PbBr₂Solute B is CH₃NH₃I、CH₃NH₃Cl or CH₃NH₃Br, the molar ratio of solute A to solute B is (0.9-1.1): 1; the mixed solvent is HCON (CH)₃)₂And HCON (CH)₃)₂Mixed solution of (2) HCON (CH) in mixed solvent₃)₂And HCON (CH)₃)₂In a volume ratio of 7: 3;

the grain size of the organic-inorganic hybrid lead halide perovskite nano crystal is 0.3-1.5 mu m;

wherein the vessel is made of stainless steel, glass or ceramic; the organic-inorganic hybrid lead halide is CH₃NH₃PbI₃、CH₃NH₃PbCl₃Or CH₃NH₃PbBr₃(ii) a The adhesive is PMMA, epoxy butyronitrile or epoxy resin.

Preferably, the mesh number of the filter screen is 2800 meshes, 150 meshes or 18 meshes;

the invention has the advantages and positive effects that:

the invention provides a preparation method and application of organic-inorganic hybrid lead halide perovskite nanocrystals with different sizes. The preparation method and the synthesis process provided by the invention are simple and easy to implement, and perovskite nanocrystals with different sizes can be controlled to grow by adjusting the aperture number of the filter sieve and the concentration of the perovskite precursor solution, so that the reaction time is saved. The method can be used for preparing the absorption layer of the high-performance perovskite solar cell.

Detailed Description

The technical solution of the present invention is further explained and illustrated by way of examples below.