CN110937623B

CN110937623B - Simple synthetic CsAgCl2Method for pure-phase inorganic non-lead perovskite

Info

Publication number: CN110937623B
Application number: CN201911217743.3A
Authority: CN
Inventors: 解仁国; 张资序; 姚佳利; 汪大洋; 杨文胜
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2021-05-14
Anticipated expiration: 2039-12-03
Also published as: CN110937623A

Abstract

The simply synthesized CsAgCl of the invention₂A method for preparing pure-phase inorganic non-lead perovskite belongs to the technical field of semiconductor nano material preparation, and firstlyMixing cesium chloride and silver chloride according to the molar ratio of 1:1, and adding oleylamine for grinding; the mixture gradually becomes compact from fluffy white powder and is attached to the wall of the container, and finally becomes fluffy white powder along with the lengthening of the grinding time, and the grinding is stopped; putting the obtained sample into a vacuum oven for heat treatment at the temperature of 60-300 ℃ for 2 hours; then immediately cooling at-10 to-40 ℃ for 1 to 2 hours to obtain the CsAgCl with high purity and high fluorescence efficiency₂Inorganic perovskite of (a). The method has the advantages of simplicity, easy operation, low energy consumption and synthesized CsAgCl₂The inorganic perovskite has the advantages of pure phase and the like, and has important significance.

Description

Simple synthetic CsAgCl2Method for pure-phase inorganic non-lead perovskite

Technical Field

The invention belongs to the technical field of semiconductor nano material preparation, and particularly relates to simply synthesized CsAgCl₂A method for pure-phase inorganic non-lead perovskite.

Background

In recent years, great progress has been made in the research of organic-inorganic lead-calcium-titanium halide solar cells, and it has been proved that the cell efficiency of the organic-inorganic lead-calcium-titanium halide solar cells can be about the same as that of CdTe thin film cells and semiconductor CuInGaS thin film cells. Nowadays, lead halide solar cells are also gradually introduced into the market, and the cell efficiency can be close to that of crystalline silicon solar cells (the cell efficiency is about 25%). But its instability in long-term use and lead toxicity greatly limit its practical application.

Perovskite is also becoming more and more deeply understood based on its importance for solar cells. Originally, one considered the replacement of divalent Pb by some non-Pb metals, such as Sn²⁺、Ge²⁺However, these divalent metals are very easily oxidized to higher valence states and are very unstable in air. To solve this problem, the David O.Scanlon group proposed that the B-site metal be selected from group IVA of the periodic Table of elements (e.g., Ge, Sn, Pb) for ABX₃Perovskite type, the electronic configuration of the outer layer at the B site is ns²For A₂BX₆Perovskite of the type, the electronic configuration of the B site being ns⁰Greatly improving the stability of the perovskite. In addition, double-layered perovskites are also being studied extensively, and the G.Wu, C.Zhou group has found double-layered all-inorganic non-lead metal perovskites Cs₂AgInCl₆White light can be emitted through a self-limited exciton luminescence path, and the fluorescent dye has a great application prospect, however, the doping can increase non-radiative recombination paths of electrons and holes, and the fluorescence efficiency is weakened. Cu-based perovskite with abundant reserves and environmental friendliness can also be used as proper B site metal in perovskite, and Wei Zheng group successfully synthesizes CsCu by using cuprous as perovskite B site₂I₃And the photoluminescence quantum yield of the material at room temperature is about 15.7 percent, and the material can still keep high stability in the atmospheric environment and has wide application prospect in the optical field.

Ag, a metal belonging to the same subgroup as Cu, is used in many fields because of its excellent conductivity⁺As the B-site metal ion in perovskite, CsAgCl can be formed₂All inorganic non-lead perovskite, but pure phase CsAgCl₂Has never been reported, and the synthesized CsAgCl has been reported₂Generally containing a heterogeneous phase. The Von H. -C. group earlier proposed the synthesis of CsAgCl₂The method comprises the steps of feeding fully dried cesium chloride and silver chloride according to the molar ratio of 1:1, carrying out a melting reaction at 310 ℃, and finally obtaining the needle-like to rod-like CsAgCl₂However, since the crystal is accompanied by occurrence of reversible phase change at 170 ℃, the obtained crystal generally contains a hetero phase. The synthesis method can synthesize CsAgCl₂However, the operation is complex, the time consumption is long, the reaction needs to be heated for a long time at a higher temperature, the energy consumption is high, the large-scale production is not facilitated, and further improvement and innovation are needed. Therefore, a method for synthesizing pure-phase CsAgCl capable of improving the fluorescence efficiency of the CsAgCl₂The method has very important significance for the synthesis of inorganic perovskite.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the problems in the background technology and provide a manipulatorThe novel method which is simple and convenient and can be synthesized in large scale at normal temperature and normal pressure is used for synthesizing pure-phase all-inorganic halogen perovskite CsAgCl₂。

The technical problem of the invention is solved by the following technical scheme:

simple synthetic CsAgCl₂The method for preparing pure-phase inorganic non-lead perovskite comprises the steps of firstly, mixing cesium chloride and silver chloride according to a molar ratio of 1:1, adding oleylamine to grind, and using 40-120 uL of oleylamine per 1mmol of cesium chloride; the mixture gradually becomes compact from fluffy white powder and is attached to the wall of the container, and finally becomes fluffy white powder along with the lengthening of the grinding time, and the grinding is stopped; irradiating under an ultraviolet lamp with excitation wavelength of 254nm to obtain a product with yellow fluorescence, and putting the obtained sample into a vacuum oven for heat treatment at 60-300 ℃ for 2 h; then immediately cooling at-10 to-40 ℃ for 1 to 2 hours, and then, the yellow fluorescence of the product becomes strong, thus obtaining the CsAgCl with high purity and high fluorescence efficiency₂Inorganic perovskite of (a).

In the invention, the CsAgCl is simply synthesized₂In the method of pure-phase inorganic non-lead perovskite, in order to improve fluorescence efficiency, the amount of oleylamine is preferably 80uL per 1mmol of cesium chloride.

In the invention, the CsAgCl is simply synthesized₂In the process for the pure phase inorganic non-lead perovskite, water may be added to the mixture before grinding in an amount of preferably 0.5mL per 1mmol of cesium chloride in order to enhance the grinding effect.

In the invention, the CsAgCl is simply synthesized₂In the method for preparing the pure-phase inorganic non-lead perovskite, the heat treatment is carried out in a vacuum oven, and the preferred heat treatment temperature is 240 ℃.

In the invention, the CsAgCl is simply synthesized₂In the method for preparing pure-phase inorganic non-lead perovskite, the cooling treatment is preferably carried out at a cooling temperature of-15 ℃ in order to further improve the fluorescence efficiency of the product.

In the invention, the CsAgCl is simply synthesized₂In the method for pure-phase inorganic non-lead perovskite, the grinding is preferably carried out in a QM-3SP04 planetary ball mill, the alternating current frequency of the ball mill is set to 35Hz, the rotating speed is 1050rad/min,the ball milling time is 2 h.

Has the advantages that:

the invention provides a simple synthesis CsAgCl for the first time₂A pure phase material method, and the fluorescence efficiency of the material is obviously enhanced through post treatment, and the material is CsAgCl₂The application in the aspect of photoelectricity provides good prospect. Under the excitation of an ultraviolet lamp with the excitation wavelength of 254nm, the product emits bright yellow fluorescence which is consistent with the fluorescence spectrum, and the pure-phase CsAgCl is synthesized by the simple and efficient method₂。

In conclusion, the method has the advantages of simplicity, easy operation, low energy consumption and synthesis of CsAgCl₂The inorganic perovskite has the advantages of pure phase and the like, and has important significance.

Drawings

FIG. 1 is CsAgCl prepared in example 1₂Absorption spectrum of inorganic perovskite material.

FIG. 2 is CsAgCl prepared in example 1₂Fluorescence emission spectra of inorganic perovskite materials.

FIG. 3 is CsAgCl prepared in example 1₂XRD spectra of inorganic perovskite materials.

FIG. 4 is CsAgCl prepared in example 1₂Inorganic perovskite material, picture of exciting luminescence under ultraviolet lamp 254 nm.

Detailed Description

Example 1:

placing 1mmol of cesium chloride, 1mmol of silver chloride, 80ul of oleylamine and 25 agate balls with the diameter of 6mm into a 25ml agate tank, setting the alternating current frequency of the ball mill to be 35Hz, setting the rotating speed to be 1050rad/min, mechanically grinding for 2h, gradually compacting the mixture from fluffy white powder to attach to the wall of the agate tank, softening the mixture, and finally changing the mixture into fluffy white powder to obtain CsAgCl₂The inorganic perovskite, now irradiated with an ultraviolet lamp with an excitation wavelength of 254nm, was found to emit yellow fluorescence. And (3) carrying out heat treatment on the obtained product in a vacuum oven at 240 ℃ for 30min, and carrying out cooling treatment at-15 ℃ for 1-2 h to find that the fluorescence intensity is obviously enhanced. Carrying out solid absorption analysis and fluorescence emission test on the product, wherein the absorption spectrum is shown in figure 1; emission of fluorescenceThe spectrogram is shown in FIG. 2; the fluorescence efficiency was 61.6%; the XRD pattern of the product is shown in FIG. 3, and it can be seen from FIG. 3 that this example produces a pure phase CsAgCl₂An inorganic perovskite. The photo of the excited luminescence of the product under UV lamp (254nm) is shown in FIG. 4. The ball mill used was a QM-3SP04 planetary ball mill.

Example 2: the amount of oleylamine in example 1 was changed from 80ul to 40ul, 100ul and 120ul, respectively, and other conditions and steps were not changed, and the fluorescence efficiencies of the respective products were measured to be 53.8%, 59.5% and 56.7%, respectively, so that the amount of oleylamine was 80ul most preferable.

Example 3:

in example 1, a drop of water was added to a solid powder mixture of cesium chloride and silver chloride before ball milling, and the ball milling time was shortened from 2 hours to 1 hour to obtain white fluffy CsAgCl₂Inorganic perovskite powder, shown for CsAgCl₂In other words, the addition of a small amount of water contributes to the reduction of the milling reaction time.

Example 4:

in example 1, the heat treatment temperature was changed from 240 ℃ to 60 ℃, 180 ℃ and 300 ℃ respectively, and the other conditions were not changed, and the fluorescence quantum efficiencies of the products obtained by the treatments at the different baking temperatures were measured to be 51.7%, 59.3% and 50.6%, respectively, so that the heat treatment temperature was most preferably 240 ℃.

Example 5:

in example 1, the cooling temperature was changed from-15 ℃ to-10 ℃ to-30 ℃ to-40 ℃ respectively, and the fluorescence quantum efficiencies of the products obtained by the treatment at different cooling temperatures were measured to be 60.7%, 59.1% and 58.6% respectively, so that the cooling treatment temperature was optimized to-15 ℃.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Simple synthetic CsAgCl₂The method for preparing pure-phase inorganic non-lead perovskite comprises the steps of firstly, mixing cesium chloride and silver chloride according to a molar ratio of 1:1, adding oleylamine to grind, and using 40-120 uL of oleylamine per 1mmol of cesium chloride; the mixture gradually becomes compact from fluffy white powder and is attached to the wall of the container, and finally becomes fluffy white powder along with the lengthening of the grinding time, and the grinding is stopped; irradiating under an ultraviolet lamp with excitation wavelength of 254nm to obtain a product with yellow fluorescence, and putting the obtained sample into a vacuum oven for heat treatment at 60-300 ℃ for 2 h; then immediately cooling at-10 to-40 ℃ for 1 to 2 hours, and then, the yellow fluorescence of the product becomes strong, thus obtaining the CsAgCl with high purity and high fluorescence efficiency₂Inorganic perovskite of (a).

2. The simple synthetic CsAgCl of claim 1₂A process for the purification of inorganic non-lead perovskite characterized in that oleylamine is used in an amount of 80uL per 1mmol of caesium chloride.

3. The simple synthetic CsAgCl of claim 1₂A process for the purification of inorganic non-lead perovskite characterized in that 0.5mL of water per 1mmol of cesium chloride is added to the mixture before grinding.

4. The simple synthetic CsAgCl of claim 1₂The method for preparing the pure-phase inorganic non-lead perovskite ore is characterized in that the heat treatment is carried out in a vacuum oven, and the heat treatment temperature is 240 ℃.

5. The simple synthetic CsAgCl of any one of claims 1 to 4₂The method for preparing the pure-phase inorganic non-lead perovskite ore is characterized in that the cooling treatment is carried out, wherein the cooling temperature is-15 ℃.