CN112981538A

CN112981538A - Method for growing large-size perovskite single crystal

Info

Publication number: CN112981538A
Application number: CN202110156359.8A
Authority: CN
Inventors: 孙文红; 王玉坤; 李磊
Original assignee: Guangxi University
Current assignee: Guangxi University
Priority date: 2021-02-04
Filing date: 2021-02-04
Publication date: 2021-06-18

Abstract

The invention belongs to the technical field of perovskite photoelectric materials, and provides a method for growing large-size perovskite single crystals, which comprises the following steps: preparing a perovskite supersaturated solution; filtering the perovskite supersaturated solution, heating the filtered perovskite supersaturated solution to the maximum threshold temperature at a preset heating rate, and separating out perovskite single crystals; and taking the separated perovskite monocrystal particles as seed crystals, placing the seed crystals in the re-prepared perovskite supersaturated solution for culturing, and growing to obtain the large-size perovskite monocrystal. The invention utilizes the inverse solubility characteristic of the perovskite saturated solution to grow the large-size perovskite single crystal, does not need complex growth equipment, has simple growth process and low equipment cost, and the grown perovskite single crystal has large size and high quality, thereby being beneficial to promoting the large-scale application of perovskite single crystal photoelectric devices.

Description

Method for growing large-size perovskite single crystal

Technical Field

The invention relates to the technical field of perovskite photoelectric materials, in particular to a method for growing large-size perovskite single crystals.

Background

In recent years, perovskite photoelectric materials have attracted much attention by researchers because of their advantages such as high optical absorption coefficient, low exciton confinement energy, and long carrier diffusion distance. Because the preparation process is very similar to that of the traditional organic/polymer photoelectric device, the perovskite photoelectric device has wide application prospect in the fields of consumer electronics, household appliances, intelligent building illumination, industry, production safety, health care, life science, environment, toys and education. The organic-inorganic hybrid perovskite has a narrow forbidden band width and becomes a star material for solar cells and photoelectric detectors. Perovskite single crystals are of particular interest as compared to polycrystalline crystals due to their lower defect density, longer carrier lifetime, and better environmental stability.

The mainstream methods for growing perovskite single crystals at present are the antisolvent method and the brilliant method. The anti-solvent method requires highly toxic solutions such as chlorobenzene as an anti-solvent to reduce the perovskite solubility, and is not suitable for large-scale application. The Briziman method has complex process and expensive equipment, and blocks the application of perovskite single crystal photoelectric devices.

Disclosure of Invention

Therefore, in order to promote the application of perovskite single crystal materials, the invention provides a simple and effective process for growing large-size high-quality perovskite single crystals without expensive and complicated large-scale equipment.

Specifically, the method is mainly realized by the following technical scheme:

a method for growing large-size perovskite single crystals by utilizing the inverse solubility characteristic of a perovskite saturated solution comprises the following steps:

preparing a perovskite supersaturated solution;

filtering the perovskite supersaturated solution, heating the filtered perovskite supersaturated solution to the maximum threshold temperature at a preset heating rate, and separating out perovskite single crystals;

and taking the separated perovskite monocrystal particles as seed crystals, placing the seed crystals in the re-prepared perovskite supersaturated solution for culturing, and growing to obtain the large-size perovskite monocrystal.

Preferably, a supersaturated solution of perovskite is prepared, specifically comprising:

excess of CH in equal proportion₃NH₃X (X ═ Cl, Br, I) powder and PbX₂Dissolving the powder in an organic solvent with a purity of more than 99.8%, and feeding the obtained solution at a temperature TStirring to form a perovskite supersaturated solution.

Preferably, the temperature T is 60-70 ℃.

Preferably, the concentration of the perovskite supersaturated solution is 1.2-2 mol/L.

Preferably, the organic solvent comprises at least one of: n, N-dimethylformyl, dimethyl sulfoxide and gamma-butyrolactone.

Preferably, the supersaturated perovskite solution is filtered using a nylon filter head.

Preferably, the diameter of the nylon filter head is 0.22-0.45 μm.

Preferably, the maximum threshold temperature is 100 to 150 ℃.

Preferably, the preset temperature rise speed is as follows: 1-2 ℃/15 min.

Preferably, the length and width of the large-size perovskite single crystal are both 1-2 in, and the height is 0.5-1 in.

Compared with the prior art, the invention has the following beneficial effects:

1. the perovskite saturated solution inverse solubility characteristic is utilized to grow large-size perovskite single crystals, complex growth equipment is not needed, highly toxic solutions like chlorobenzene and the like are not needed, and the growth process is simple;

2. the length and width of the grown perovskite single crystal are 1-2 in, the height is 0.5-1 in, the size is large, the quality is high, and the perovskite single crystal is suitable for large-scale application;

3. the growth equipment has low cost and does not need expensive and complicated large-scale equipment.

Drawings

FIG. 1 is a flow chart of a method for growing large-size perovskite single crystals by utilizing the inverse solubility characteristic of a saturated perovskite solution;

FIG. 2 shows a large CH format according to an embodiment of the present invention₃NH₃PbBr₃XRD diffractogram of single crystal;

FIG. 3 shows a large CH format according to an embodiment of the present invention₃NH₃PbBr₃X-ray rocking curve of single crystal;

FIG. 4 shows a large CH format according to an embodiment of the present invention₃NH₃PbBr₃Photoluminescence spectrum of single crystals;

FIG. 5 shows a large CH format according to an embodiment of the present invention₃NH₃PbBr₃Time resolved photoluminescence spectra of single crystals;

FIG. 6 shows a large CH format according to an embodiment of the present invention₃NH₃PbBr₃Photocurrent and dark current of the single crystal photodetector.

FIG. 7 shows a large CH format provided by an embodiment of the present invention₃NH₃PbBr₃The detectivity of the single crystal photodetector.

Detailed Description

In order to make the core idea of the present invention more clearly understood, the following detailed description will be made with reference to the accompanying drawings.

As shown in fig. 1, an embodiment of the present invention provides a method for growing a large-size perovskite single crystal by using an inverse solubility characteristic of a perovskite saturated solution, specifically including the following steps:

s101, preparing a perovskite supersaturated solution.

The specific implementation mode can be as follows: excess of CH in equal proportion₃NH₃X (X ═ Cl, Br, I) powder and PbX₂The powder is dissolved in an organic solvent with the purity of more than 99.8 percent and is placed on a heating table to be stirred under the condition of temperature T, so that a perovskite supersaturated solution is formed.

In a preferred embodiment, the temperature T is 60-70 ℃.

In a preferred embodiment, the organic solvent having a purity of greater than 99.8% comprises at least one of: n, N-dimethylformyl, dimethyl sulfoxide and gamma-butyrolactone.

In a preferred embodiment, the concentration of the perovskite supersaturated solution is 1.2-2 mol/L.

S102, filtering the perovskite supersaturated solution, heating the filtered perovskite supersaturated solution to the maximum threshold temperature at a preset heating rate, and separating out perovskite single crystals.

In a preferred embodiment, the supersaturated solution of perovskite is filtered using a nylon filter head.

In a preferred embodiment, the diameter of the nylon filter head is 0.22-0.45 μm.

In a preferred embodiment, the maximum threshold temperature is 100 to 150 ℃. When the maximum threshold temperature is exceeded, continuing to raise the temperature does not significantly increase the yield of crystals (perovskite single crystals).

In a preferred embodiment, the preset temperature-rise speed is as follows: 1-2 ℃/15 min.

S103, taking the precipitated perovskite single crystal particles as seed crystals, placing the seed crystals in a re-prepared perovskite supersaturated solution for culturing, and growing to obtain the large-size perovskite single crystal.

In a preferred embodiment, the length, width, length and width of the grown large-size perovskite single crystal are 1-2 in, and the height is 0.5-1 in.

For example, when X ═ Br, then growth gives a large size CH₃NH₃PbBr₃Single crystal, large size CH grown using the inverse solubility characteristics of the saturated solution of perovskite, as shown in FIG. 2₃NH₃PbBr₃The single crystal only has a {001} crystal face cluster, and shows better crystallization quality.

As shown in FIG. 3, the full width at half maximum of only 0.0254 ° demonstrates the large size CH₃NH₃PbBr₃The single crystal has a high crystalline quality.

As shown in FIG. 4, the large size CH₃NH₃PbBr₃The intrinsic peak of the single crystal is positioned at 540nm, the full width at half maximum is small, and the crystal quality is high.

As shown in fig. 5, the large size CH₃NH₃PbBr₃The average carrier lifetime of the single crystal is up to 179 nanoseconds.

As shown in FIG. 6, the photo-dark current ratio of the photo-current and the dark current of the perovskite single crystal detector reaches 23.5 under the forward bias of 1.5V, and the perovskite single crystal detector shows better switching characteristics.

FIG. 7 shows the optical responsivity of perovskite single crystal detector, and the detectivity reaches 5.85X 10 under the forward bias of 1.5V¹⁰Jones。

The foregoing detailed description of the embodiments of the present invention has been presented for the purpose of illustrating the principles and implementations of the present invention, and the description of the embodiments is only provided to assist understanding of the core concepts of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A method for growing large-size perovskite single crystals by utilizing the inverse solubility characteristic of a perovskite saturated solution is characterized by comprising the following steps of:

preparing a perovskite supersaturated solution;

2. The method for growing large-size perovskite single crystals by utilizing the inverse solubility characteristic of the perovskite saturated solution as claimed in claim 1, wherein the preparation of the perovskite supersaturated solution specifically comprises the following steps:

excess of CH in equal proportion₃NH₃X (X ═ Cl, Br, I) powder and PbX₂The powder is dissolved in an organic solvent with the purity of more than 99.8 percent, and the obtained solution is stirred under the condition of temperature T to form a perovskite supersaturated solution.

3. The method for growing a large-sized perovskite single crystal using the inverse solubility characteristic of a perovskite saturated solution as claimed in claim 2, wherein the temperature T is 60 to 70 ℃.

4. The method for growing large-size perovskite single crystals by utilizing the inverse solubility characteristic of the perovskite saturated solution as claimed in claim 2 or 3, wherein the concentration of the perovskite supersaturated solution is 1.2 to 2 mol/L.

5. The method for growing a large-sized perovskite single crystal using the inverse solubility characteristic of a perovskite saturated solution as claimed in claim 4, wherein the organic solvent comprises at least one of: n, N-dimethylformyl, dimethyl sulfoxide and gamma-butyrolactone.

6. The method for growing large-size perovskite single crystals by utilizing the inverse solubility characteristic of the perovskite saturated solution as claimed in claim 1, wherein the perovskite supersaturated solution is filtered by using a nylon filter head.

7. The method for growing large-size perovskite single crystals by utilizing the inverse solubility characteristic of the perovskite saturated solution as claimed in claim 6, wherein the diameter of the nylon filter head is 0.22-0.45 μm.

8. The method for growing a large-size perovskite single crystal using the inverse solubility characteristic of a saturated solution of perovskite as set forth in claim 1, 6 or 7, wherein the maximum threshold temperature is 100 to 150 ℃.

9. The method for growing a large-sized perovskite single crystal using the inverse solubility characteristic of the perovskite saturated solution as set forth in claim 8, wherein the preset temperature rise rate is: 1-2 ℃/15 min.

10. The method for growing a large-size perovskite single crystal by utilizing the inverse solubility characteristic of a perovskite saturated solution as claimed in claim 1, wherein the length and width of the large-size perovskite single crystal are both 1-2 in and the height is 0.5-1 in.