阅读说明：本技术 一种三维钙钛矿的降维方法 (Dimension reduction method of three-dimensional perovskite ) 是由 白雪 胡强 高旭鹏 武振楠 张宇 陆敏 于伟泳 于 2021-10-11 设计创作，主要内容包括：本发明适用于半导体技术领域,提供了一种三维钙钛矿的降维方法,包括以下步骤：S1：前驱体溶液的制备,将一定量的十八烯、油酸以及碳酸铯放在三颈瓶A中,其次在惰性气体氛围下对位于三颈瓶A中的混合物进行加热,得到澄清液体；S2：将溴化铅、溴化镁、油酸以及油胺加入装有十八烯的三颈瓶B中,其次对三颈瓶B进行抽气,并在惰性气体氛围下对位于三颈瓶B中的混合物进行加热,得到混合溶液A；S3：将前驱体溶液注入混合溶液A中进行加热,得到混合溶液B,混合溶液B冰水浴后得到降维后的钙钛矿。本发明利用热注入合成法,通过金属离子表面调控胶体合成动力学过程,制备高效的准二维钙钛矿,实现了三维钙钛矿的降维工程。(The invention is suitable for the technical field of semiconductors, and provides a dimension reduction method of three-dimensional perovskite, which comprises the following steps: s1: preparing a precursor solution, namely putting a certain amount of octadecene, oleic acid and cesium carbonate in a three-necked bottle A, and heating the mixture in the three-necked bottle A in an inert gas atmosphere to obtain a clear liquid; s2: adding lead bromide, magnesium bromide, oleic acid and oleylamine into a three-necked bottle B filled with octadecene, then exhausting air from the three-necked bottle B, and heating a mixture in the three-necked bottle B in an inert gas atmosphere to obtain a mixed solution A; s3: and injecting the precursor solution into the mixed solution A for heating to obtain a mixed solution B, and performing ice-water bath on the mixed solution B to obtain the perovskite with the reduced dimension. The invention utilizes a hot injection synthesis method, and regulates the dynamic process of colloid synthesis through the surface of metal ions to prepare high-efficiency quasi-two-dimensional perovskite, thereby realizing the dimension reduction engineering of three-dimensional perovskite.)

1. A dimension reduction method of three-dimensional perovskite is characterized by comprising the following steps:

s1: preparing a precursor solution:

firstly, putting a certain amount of octadecene, oleic acid and cesium carbonate in a three-necked bottle A, introducing inert gas into the three-necked bottle A, and stirring and heating a mixture of the octadecene, the oleic acid and the cesium carbonate to 120 ℃ until the mixture is dissolved into clear liquid;

s2: firstly, adding lead bromide, magnesium bromide, oleic acid and oleylamine into a three-necked bottle B filled with octadecene, exhausting the three-necked bottle B, introducing inert gas into the three-necked bottle B, stirring and heating a mixture of the lead bromide, the magnesium bromide, the oleic acid, the oleylamine and the octadecene in the three-necked bottle B to 120 ℃ to obtain a mixed solution A;

s3: heating the mixed solution A to 185 ℃, and injecting a certain amount of precursor solution into a three-necked bottle B filled with the mixed solution A to obtain a mixed solution B;

s4: firstly, after injecting the precursor solution for 5s, quickly cooling the mixed solution B, and then centrifugally dispersing the mixed solution B into the nonpolar solvent.

2. The dimension reduction method for the three-dimensional perovskite as claimed in claim 1, wherein in the S1, the volume ratio of octadecene to oleic acid is 10: 1, the concentration of cesium carbonate is 0.04 g/ml.

3. The dimension reduction method for three-dimensional perovskite according to claim 1, wherein the inert gas introduced in S1 and S2 is nitrogen.

4. The dimension reduction method of the three-dimensional perovskite of claim 1, wherein in the S2, the volume ratio of octadecene, oleic acid and oleylamine is 10: 1: 1, the molar ratio of magnesium bromide to lead bromide is 0-2: 1.

5. the dimension reduction method for three-dimensional perovskite according to claim 1, wherein in the step S3, the volume ratio of the precursor solution to the mixed solution a is 1: 10.

6. the dimension reduction method for the three-dimensional perovskite according to claim 1, wherein in S4, the centrifugal rotation speed of the mixed solution B is 5000-10000 r/m.

7. The method of dimensionality reduction of the three-dimensional perovskite of claim 6, wherein the non-polar solvent is toluene.

Technical Field

The invention belongs to the technical field of semiconductors, and particularly relates to a dimension reduction method of three-dimensional perovskite.

Background

Metal halide perovskites have become one of the research hotspots in recent years due to the adjustability of their chemical composition and crystal structure and the corresponding physical and optoelectronic properties, and are classified into three-dimensional, two-dimensional, one-dimensional and zero-dimensional perovskites by introducing appropriate chemical components into the perovskite structure, depending on the spatial ordering and connection of the metal halide octahedral units.

The traditional synthesis method of the quasi-two-dimensional perovskite is very limited, and the transformation from the three-dimensional perovskite to the quasi-two-dimensional perovskite is realized by basically adopting a liquid-phase crystallization method for preparing a perovskite material and a spin-coating method for preparing a perovskite thin film.

Traditional crystallization methods rely on slow cooling of hot concentrated solutions or rapid evaporation of solvents, which makes it very difficult to control the morphology, size, and chemical composition of materials at the nanoscale.

Disclosure of Invention

An object of an embodiment of the present invention is to provide a dimension reduction method for three-dimensional perovskite, which aims to solve the problem that the traditional crystallization method relies on slow cooling of hot concentrated solution or rapid evaporation of solvent, which makes it very difficult to control the morphology, size and chemical composition of the material at the nanoscale.

The embodiment of the invention is realized in such a way that the dimension reduction method of the three-dimensional perovskite comprises the following steps:

s1: preparing a precursor solution:

firstly, putting a certain amount of octadecene, oleic acid and cesium carbonate in a three-necked bottle A, introducing inert gas into the three-necked bottle A, and then stirring and heating a mixture of the octadecene, the oleic acid and the cesium carbonate to 120 ℃ until the mixture is dissolved into clear liquid (precursor solution);

s2: adding lead bromide, magnesium bromide, oleic acid and oleylamine into a three-necked bottle B filled with octadecene, then exhausting the three-necked bottle B, introducing inert gas into the three-necked bottle B, stirring and heating a mixture of the lead bromide, the magnesium bromide, the oleic acid, the oleylamine and the octadecene in the three-necked bottle B to 120 ℃ to obtain a mixed solution A;

s3: heating the mixed solution A to 185 ℃, and injecting a certain amount of precursor solution into a three-necked bottle B filled with the mixed solution A to obtain a mixed solution B;

s4: firstly, after injecting the precursor solution for 5s, quickly cooling the mixed solution B, and then centrifugally dispersing the mixed solution B into the nonpolar solvent.

On the basis of the technical scheme, the invention also provides the following optional technical scheme:

the further technical scheme is as follows: in the S1, the volume ratio of octadecene to oleic acid is 10: 1, the concentration of cesium carbonate is 0.04 g/ml.

The further technical scheme is as follows: the inert gas introduced in the S1 and the S2 is nitrogen.

The further technical scheme is as follows: in the S2, the volume ratio of octadecene, oleic acid and oleylamine is 10: 1: 1, the molar ratio of magnesium bromide to lead bromide is 0-2: 1.

the further technical scheme is as follows: in the step S3, the volume ratio of the precursor solution to the mixed solution A is 1: 10.

the further technical scheme is as follows: in the step S4, the centrifugal rotation speed of the mixed solution B is 5000-10000 r/m.

The further technical scheme is as follows: the non-polar solvent is toluene.

According to the dimension reduction method of the three-dimensional perovskite, provided by the embodiment of the invention, lead bromide and magnesium bromide are fully dissolved in an octadecene solvent mixed with surfactants (oleic acid and oleylamine) by adopting a hot injection method, lead atoms, magnesium atoms and bromine atoms are fully contacted with the surfactants (oleic acid and oleylamine), a precursor cesium source is injected after a reaction is carried out for a period of time at a certain temperature, the conversion from the three-dimensional perovskite to the quasi-two-dimensional perovskite is realized under the regulation and control of magnesium ions, and the quantity and arrangement mode of ligand adsorption can be changed by regulating the quantity of the magnesium bromide.

Drawings

FIG. 1 is a morphology diagram of a quasi-two-dimensional perovskite incorporating a high amount of magnesium bromide in the present invention.

FIG. 2 is an X-ray diffraction pattern of a quasi-two-dimensional perovskite according to the present invention.

FIG. 3 is an ultraviolet-visible light absorption diagram of the conversion of a three-dimensional perovskite into a quasi-two-dimensional perovskite after magnesium bromide is added in the present invention.

FIG. 4 is a comparison graph of photoluminescence peak positions and fluorescence quantum efficiencies of three-dimensional perovskite and quasi-two-dimensional perovskite in the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Specific implementations of the present invention are described in detail below with reference to specific embodiments.

Example 1

S1: placing 2.5ml of oleic acid, 30ml of octadecene and 0.814g of cesium carbonate in a 100ml three-necked flask A;

s2: vacuumizing a three-necked bottle A filled with a mixture of oleic acid, octadecene and cesium carbonate for 1 hour;

s3: keeping the mixture of oleic acid, octadecene and cesium carbonate at 150 ℃ for 3 hours in a nitrogen atmosphere until the mixture of oleic acid, octadecene and cesium carbonate forms a clear precursor solution;

s4: filling 0.138g of lead bromide, 0.069g of magnesium bromide, 1ml of oleylamine, 1ml of oleic acid and 10ml of octadecene into a 100ml three-necked bottle B;

s5: vacuumizing the three-necked bottle B, heating the mixture of lead bromide, magnesium bromide, oleylamine, oleic acid and octadecene to 120 ℃ in a vacuum state, and keeping the state for 1 hour to obtain a mixed solution A;

s6: rapidly heating the mixed solution A at 120 ℃ to 185 ℃, and injecting 1ml of precursor solution into the mixed solution A to obtain a mixed solution B;

s7: after the mixed solution B reacts for 5s, the mixed solution B is quickly subjected to ice-water bath quenching reaction and then is subjected to centrifugal purification.

Example 2

The same procedure as in example 1 was followed except that the amount of magnesium bromide in step 2 of example 1 was changed to 0.104g, and the other conditions were kept the same.

Example 3

The same procedure as in example 1 was followed except that the amount of magnesium bromide in step 2 of example 1 was changed to 0.138g, and the other conditions were kept the same.

Example 4

The same procedure as in example 1 was followed except that magnesium bromide was not added in step 2 of example 1 and the other conditions were kept the same.

By adjusting the amount of the added magnesium bromide, the introduction of the magnesium bromide in a high amount can promote the conversion of the three-dimensional perovskite quantum dots to the quasi-two-dimensional perovskite, and finally the uniform quasi-two-dimensional perovskite is obtained. Experiments prove that compared with the graph 1 (a-d), the appearance and the size of the obtained quasi-two-dimensional perovskite after dimension reduction are more uniform when the magnesium bromide is added in an amount of (2: 1); secondly, experiments prove that the quasi-two-dimensional perovskite obtained by adding magnesium bromide has good relative stability, the X-ray diffraction peak presents regular periodic diffraction peaks (as shown in figure 2), after the magnesium bromide is added, the absorption peak of the three-dimensional perovskite gradually disappears, two absorption peaks of the quasi-two-dimensional perovskite appear (as shown in figure 3), and compared with green light emission of the three-dimensional perovskite quantum dots before dimension reduction, the quasi-two-dimensional perovskite after dimension reduction presents deep blue light emission and keeps higher quantum efficiency (as shown in figure 4).

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present disclosure, and all the changes or substitutions should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.