阅读说明：本技术 一种圆片状钙钛矿单晶的制备方法 (Preparation method of disk-shaped perovskite single crystal ) 是由 仇明侠 崔向前 王萌 叶志祥 李波波 王宁 陈业旺 吴丹 于 2021-06-24 设计创作，主要内容包括：本发明公开一种圆片状钙钛矿单晶的制备方法,通过利用甲胺卤化物和卤化铅混合后溶于有机溶剂中,然后在搅拌条件下进行加热处理得到钙钛矿溶液,所述钙钛矿溶液浓度为0.5M-1.8M；然后以3000r/min-9000r/min的转速将所述钙钛矿溶液旋涂在基板上,制得所述圆片状钙钛矿单晶。其中,通过所述溶液浓度与所述转速的匹配,可以调控不同形状单晶的生长以及制备出不同尺寸的钙钛矿材料。该制备方法工艺简单,制备的圆片状钙钛矿单晶结构规则,均为圆片状。(The invention discloses a preparation method of a disk-shaped perovskite single crystal, which comprises the steps of mixing methylamine halide and lead halide, dissolving the mixture in an organic solvent, and then heating the mixture under the condition of stirring to obtain a perovskite solution, wherein the concentration of the perovskite solution is 0.5-1.8M; and then spin-coating the perovskite solution on a substrate at a rotating speed of 3000r/min-9000r/min to prepare the disk-shaped perovskite single crystal. The growth of single crystals in different shapes can be regulated and controlled and perovskite materials with different sizes can be prepared by matching the concentration of the solution with the rotating speed. The preparation method has simple process, and the prepared wafer-shaped perovskite single crystals have regular structures and are all in the shape of wafers.)

1. A method for producing a disk-shaped perovskite single crystal, characterized by comprising the steps of:

providing a perovskite solution, the concentration of the perovskite solution being between 0.5M and 1.8M;

and spin-coating the perovskite solution on a substrate at a rotating speed of 3000r/min-9000r/min to obtain the disk-shaped perovskite single crystal.

2. The method for producing a disk-shaped perovskite single crystal according to claim 1, wherein the production of the perovskite solution comprises the steps of:

mixing methylamine halide and lead halide and adding the mixture into an organic solvent to obtain a mixed solution;

and heating the mixed solution under the stirring condition, and reacting to obtain the perovskite solution.

3. The method for producing a disk-shaped perovskite single crystal as claimed in claim 2, wherein the organic solvent is one or more of DMF, DMSO and γ -GBL.

4. The method for producing a disk-shaped perovskite single crystal as claimed in claim 2, wherein the methylamine halide is MABr and the lead halide is PbBr₂。

5. The method for producing a disk-shaped perovskite single crystal according to claim 1, wherein the step of spin-coating the perovskite solution on the substrate at a rotational speed of 3000r/min to 9000r/min comprises:

providing a substrate, and fixing the substrate on a spin coater;

and dropwise adding the perovskite solution onto the substrate for spin coating, wherein the rotation speed of the spin coater is set to be 3000r/min-9000 r/min.

6. A method for producing a disk-shaped perovskite single crystal as claimed in claim 1, wherein the perovskite solution is spin-coated on the substrate at a rotational speed of 3000r/min to 9000r/min, and wherein the method further comprises the steps of:

and ultrasonically cleaning the substrate by one or more of deionized water, acetone, isopropanol and ethanol, drying by nitrogen, and treating the dried substrate by ultraviolet ozone.

7. The method for producing a disk-shaped perovskite single crystal as claimed in claim 1, wherein the perovskite solution is spin-coated on the substrate at a rotational speed of 3000r/min to 9000r/min, and thereafter further comprising the steps of:

and annealing the spin-coated substrate in a nitrogen atmosphere with the water and oxygen content less than 0.01ppm, and obtaining the wafer-shaped perovskite single crystal after the annealing is finished.

8. The method for producing a disk-shaped perovskite single crystal according to claim 7, wherein the annealing temperature of the annealing treatment is 30 to 90 ℃ and the annealing time is 5 to 10 min.

9. The method for producing a disk-shaped perovskite single crystal as claimed in claim 1, wherein the perovskite solution is spin-coated on a substrate at a rotation speed of 6000r/min at a concentration of 1.0M to produce the disk-shaped perovskite single crystal.

Technical Field

The invention relates to the technical field of semiconductor materials, in particular to a preparation method of a wafer-shaped perovskite single crystal.

Background

The organic metal halide perovskite material has excellent photoelectric properties, and the organic metal halide perovskite has the advantages of convenient shape regulation and control, simple preparation process, adjustable direct band gap, large absorption coefficient, long carrier diffusion length, low defect state density and the like. The perovskite material is used as a laser gain medium, can generate a stimulated emission phenomenon, and can also be an optical resonant cavity, so that the perovskite material has been widely researched in the application aspect of lasers.

Many perovskite structures with different morphologies are available, such as square sheet, spherical, linear, cubic and cubic pyramid. At present, the preparation method of the disk-shaped perovskite mainly comprises a blade coating method, an anti-solvent recrystallization method and a two-step chemical vapor deposition method. However, the existing preparation method has some defects, such as poor controllability and low repeatability of a blade coating method, perovskite single crystals in other shapes are mixed in the prepared wafer-shaped perovskite single crystals, and the prepared wafer-shaped perovskite single crystals have low purity; the time for preparing the disk-shaped perovskite single crystal by the anti-solvent recrystallization method is long; the two-step chemical vapor deposition preparation method has more complex process.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a preparation method of a disk-shaped perovskite single crystal, and aims to solve the problems of poor controllability, low repeatability, low purity, long required time and complex process of the existing preparation method of the disk-shaped perovskite single crystal.

The technical scheme of the invention is as follows:

a method for producing a disk-shaped perovskite single crystal, comprising the steps of:

providing a perovskite solution, the concentration of the perovskite solution being between 0.5M and 1.8M;

and spin-coating the perovskite solution on a substrate at a rotating speed of 3000r/min-9000r/min to obtain the disk-shaped perovskite single crystal.

The method for producing a wafer-shaped perovskite single crystal includes the steps of:

mixing methylamine halide and lead halide and adding the mixture into an organic solvent to obtain a mixed solution;

and heating the mixed solution under the stirring condition, and reacting to obtain the perovskite solution.

The preparation method of the disk-shaped perovskite single crystal is characterized in that the organic solvent is one or more of DMF, DMSO and gamma-GBL.

The preparation method of the disk-shaped perovskite single crystal comprises the steps of taking MABr as methylamine halide and taking PbBr as lead halide₂。

The method for producing a wafer-shaped perovskite single crystal, wherein the step of spin-coating the perovskite solution on a substrate at a rotational speed of 3000r/min to 9000r/min comprises:

providing a substrate, and fixing the substrate on a spin coater;

and dropwise adding the perovskite solution onto the substrate for spin coating, wherein the rotation speed of the spin coater is set to be 3000r/min-9000 r/min.

The preparation method of the disk-shaped perovskite single crystal comprises the following steps of coating the perovskite solution on a substrate in a spinning mode at a rotating speed of 3000r/min-9000 r/min:

and ultrasonically cleaning the substrate by one or more of deionized water, acetone, isopropanol and ethanol, drying by nitrogen, and treating the dried substrate by ultraviolet ozone.

The preparation method of the disk-shaped perovskite single crystal comprises the following steps of coating the perovskite solution on a substrate in a rotating speed of 3000r/min-9000r/min in a rotating mode:

and annealing the spin-coated substrate in a nitrogen atmosphere with the water and oxygen content less than 0.01ppm, and obtaining the wafer-shaped perovskite single crystal after the annealing is finished.

The preparation method of the disk-shaped perovskite single crystal comprises the following steps of annealing at the temperature of 30-90 ℃ for 5-10 min.

The method for producing a wafer-shaped perovskite single crystal comprises spin-coating the perovskite solution on a substrate at a rotation speed of 6000r/min when the concentration of the perovskite solution is 1.0M, thereby producing the wafer-shaped perovskite single crystal.

Has the advantages that: the method comprises the steps of mixing methylamine halide and lead halide, dissolving the mixture in an organic solvent, and then heating the mixture under the condition of stirring to obtain a perovskite solution, wherein the concentration of the perovskite solution is 0.5-1.8M; and then spin-coating the perovskite solution on a substrate at a rotating speed of 3000r/min-9000r/min to prepare the disk-shaped perovskite single crystal. Uniformly coating the perovskite solution on the substrate by using centrifugal force generated during rotation, and forming supersaturated solution along with the volatilization of the solvent, wherein the perovskite single crystal begins to be separated out; the growth of single crystals in different shapes can be regulated and controlled and perovskite materials with different sizes can be prepared by matching the concentration of the solution with the rotating speed. The preparation method for preparing the disk-shaped perovskite single crystal is simple, the prepared disk-shaped perovskite single crystal is regular in structure, the perovskite single crystals grown on the substrate are uniform in shape and are all disk-shaped, and the surface roughness of the disk-shaped single crystal perovskite material is low.

Drawings

FIG. 1 is a flow chart of a process for producing a wafer-shaped perovskite single crystal.

FIG. 2 is a flow chart of a manufacturing process of a specific example of a wafer-shaped perovskite single crystal.

FIG. 3 is a schematic view of a spin coating process in a method for producing a wafer-shaped perovskite single crystal.

FIG. 4 is a scanning electron microscope microscopic structure view of the disk-shaped perovskite single crystal of example 1.

FIG. 5 is a scanning electron microscope microscopic structure view of the disk-shaped perovskite single crystal of example 1.

FIG. 6 is a scanning electron microscope microscopic structure view of the disk-shaped perovskite single crystal of example 1.

Detailed Description

The present invention provides a method for producing a wafer-shaped perovskite single crystal, and the present invention will be described in further detail below in order to make the object, the technical scheme, and the effect of the present invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The method has the advantages of good controllability, high repeatability, simple process and high purity of the single crystal, and is the most preferable for enterprises to improve the efficiency of preparing the perovskite single crystal and save the production cost, but the existing preparation processes can not meet the conditions at the same time.

Based on this, the present embodiment provides a method for preparing a wafer-shaped perovskite single crystal, as shown in fig. 1, which specifically includes the following steps:

s10, providing a perovskite solution, wherein the concentration of the perovskite solution is 0.5-1.8M;

s20, spin-coating the perovskite solution on a substrate at a rotating speed of 3000r/min-9000r/min to obtain the disk-shaped perovskite single crystal.

Specifically, as shown in fig. 2, in some embodiments, in S10, the preparation of the perovskite solution includes the following steps:

mixing methylamine halide and lead halide and adding the mixture into an organic solvent to obtain a mixed solution;

and heating the mixed solution under the stirring condition, and reacting to obtain the perovskite solution.

In some embodiments, the organic solvent is one or more of DMF (N, N-dimethylformamide), DMSO (dimethyl sulfoxide), γ -GBL (γ -butyrolactone). Preferably, the stirrer is added when the mixed solution is stirred, which is beneficial to more uniformly dispersing methylamine halide and lead halide in the organic solvent, and the obtained perovskite solution is more uniform.

The methylamine halide is represented by MAX, and the lead halide is represented by PbX₂Means, in some embodiments, the MAX and the PbX₂Wherein X is one or more of halogen atoms Cl, Br and I. In this embodiment, methylamine halide MAX and lead halide PbX are selected₂Has the advantages of stability at room temperature, easy acquisition of raw materials and providing a favorable foundation for saving cost and reducing production requirements.

In some embodiments, the molar ratio of the methylamine halide to the lead halide is 1:1, and the concentration of the perovskite solution is 0.5M-1.8M, at which a suitable single crystal growth rate of the perovskite solution during spin coating is facilitated, and when the concentration is too high, the perovskite single crystal is grown into a pyramid shape, and the grown single crystal is stacked; when the concentration is too low, the solvent is not easy to volatilize along with the rotation of the spin coater, so that the growth of the single crystal is not facilitated, and the grown single crystal is not uniformly distributed and cannot meet the production requirement. Preferably, the concentration of the perovskite solution is 1.0M.

In some embodiments, the step of spin coating the perovskite solution on the substrate at a rotation speed of 3000r/min to 9000r/min in S20 comprises:

providing a substrate, and fixing the substrate on a spin coater;

and dropwise adding the perovskite solution onto the substrate for spin coating, wherein the rotation speed of the spin coater is set to be 3000r/min-9000 r/min.

In some embodiments, prior to spin coating the perovskite solution on a substrate, further comprising the steps of: the substrate is ultrasonically cleaned for many times by one or more of deionized water, acetone, isopropanol and ethanol, then is dried by nitrogen, and is treated by ultraviolet ozone after the drying is finished. The substrate is subjected to ultrasonic cleaning and drying under strict conditions before spin coating, and the method is mainly used for reducing other impurities on the substrate and avoiding the defect that the purity of the obtained perovskite single crystal is not high and the production requirement is not met due to the adverse effect of the impurities on the subsequent spin coating process and the single crystal growth process.

In some embodiments, as shown in fig. 3, the perovskite solution is dropped on the cleaned substrate and uniformly coated on the substrate under the protection of inert gas, and then spin coating is performed, and the rotation speed range of the spin coater is set to 3000-. Wherein the inert gas is nitrogen, but is not limited thereto. In this embodiment, the acceleration of the spin coater is 1200-1800r/min². Wherein, when the rotating speed is from 700r/min to 6000r/min, the shape of the single crystal is converted from a square sheet shape to a round sheet shape. The spin coater generates a centrifugal force when rotating, the perovskite solution is uniformly coated on the substrate, the solvent volatilizes along with the rotation, so that a supersaturated solution is formed, the perovskite single crystal begins to precipitate, the thin film is thinned by a spin coating mode, so that a plurality of perovskite crystal nuclei are generated and grow simultaneously, the local ion concentration is insufficient, the growth power is insufficient, the growth of a cubic flaky perovskite structure is limited, and the wafer-shaped perovskite single crystal is formed; in other words, as the spin coating process is carried out, the solvent is volatilized continuously, the perovskite solution forms a supersaturated solution suddenly at a certain moment, so that a great number of crystal nuclei are generated in the perovskite thin film formed by the spin coating and grow simultaneously, the ion concentration near each crystal nucleus is insufficient, the growth power of the crystal nuclei is insufficient, and the square flaky single crystal cannot grow, so that the requirement of the embodiment for producing the wafer-shaped perovskite single crystal is met.

And finally, carrying out annealing treatment on the spin-coated substrate in a nitrogen atmosphere with the water and oxygen content less than 0.01ppm, and obtaining the wafer-shaped perovskite single crystal after the annealing is finished.

In some embodiments, the annealing temperature of the annealing treatment is 30-90 ℃ and the annealing time is 5-10 min. Annealing treatment is carried out at 30-90 ℃ for 5-10min, the grown crystal structure is further perfected, so that the surface defects of the perovskite single crystal are reduced, and the grown perovskite single crystal is damaged by overhigh annealing temperature and overlong annealing time, and the surface defects of the crystal are increased; however, when the annealing temperature is too low or the annealing time is insufficient, the effects of improving the crystal structure and reducing the surface defects of the perovskite single crystal cannot be achieved.

In addition, the growth rate of the perovskite single crystal can be controlled by adjusting the concentration of the perovskite solution, the rotating speed of the spin coater, the annealing temperature and the annealing time, so that the growth of the single crystals in different shapes can be regulated, the perovskite single crystal materials with different sizes can be prepared, the appearance is in a round sheet shape, and the size is in a micron order. In addition, the growth process of the perovskite single crystal is limited by a spin coating process, namely, a solvent is volatilized in the spin coating process, and the concentration of the perovskite solution on the substrate is supersaturated uniformly under the action of centrifugal force film formation, so that the prepared wafer-shaped perovskite single crystal has regular appearance, and all the single crystals on the substrate have low surface roughness and uniform appearance and are in a wafer shape.

The method for producing a wafer-shaped perovskite single crystal of the present invention is further explained below by way of specific examples:

example 1

Specifically, the methylamine halide MAX is MABr, and the lead halide PbX is₂Is PbBr₂(ii) a The MABr and PbBr₂The mass of (A) is 0.112g and 0.367g respectively; the MABr and PbBr are added₂And mixing, dissolving in 1mL of DMF solvent, adding a stirrer, and stirring at 70 ℃ for 12h for full mixing to obtain the perovskite solution, wherein the concentration of the perovskite solution is 1M. Stirring and mixing at 70 ℃ to facilitate the MABr and PbBr₂Diffusion in DMF solvent resulted in a homogeneous solution of the perovskite.

Providing a substrate, sequentially ultrasonically cleaning the substrate for 40min by using deionized water, acetone, isopropanol and ethanol, drying by using nitrogen, and treating the substrate for 30min by using ultraviolet ozone after drying and before spin coating.

Under the protection of inert gas, the perovskite solution is dripped on the cleaned substrate and is uniformly coated on the substrate, the rotating speed of the spin coater is set to be 6000r/min, and the acceleration is set to be 1500r/min²Spinning the perovskite solution under the condition that the spinning time is 60sCoating on the clean substrate treated by ultraviolet ozone. When the concentration of the perovskite solution is 1M, the proper single crystal growth speed is achieved at the rotating speed of 6000r/min, and a necessary foundation is provided for preparing perovskite single crystals with uniform sizes; when the rotating speed exceeds 6000r/min, the solvent in the perovskite solution is volatilized too fast, so that the growth speed of the single crystal is easy to be accelerated, and the obtained perovskite single crystal is uneven in size; when the rotating speed is lower than 6000r/min, the solvent is not easy to volatilize, which is not beneficial to the growth of single crystals.

And after the spin coating is finished, annealing the spin-coated substrate in a nitrogen atmosphere with the water and oxygen content less than 0.01ppm, setting the annealing temperature at 30 ℃ and the annealing time at 5min, and finally preparing the wafer-shaped perovskite single crystal. Annealing at 30 ℃ will further improve the crystal structure that has grown out and reduce the surface defects of the resulting perovskite single crystal.

As shown in fig. 4, which is a microstructure diagram observed by a scanning electron microscope in example 1, it is understood from the microstructure diagram that the perovskite single crystal prepared by this method is in a wafer shape, and the shapes of all the single crystals are regular and uniform.

Example 2

Specifically, the methylamine halide MAX is MABr, and the lead halide PbX is₂Is PbBr₂(ii) a The MABr and PbBr₂The mass of (A) is 0.112g and 0.367g respectively; the MABr and PbBr are added₂And dissolving the mixture in 2mL of DMF solvent after mixing, adding a stirrer, and stirring for 12h at 70 ℃ for full mixing to obtain the perovskite solution, wherein the concentration of the perovskite solution is 0.5M. Stirring and mixing at 70 ℃ to facilitate the MABr and PbBr₂Diffusion in DMF solvent resulted in a homogeneous solution of the perovskite.

Providing a substrate, sequentially ultrasonically cleaning the substrate for 40min by using deionized water, acetone, isopropanol and ethanol, drying by using nitrogen, and treating the substrate for 30min by using ultraviolet ozone after drying and before spin coating.

Under the protection of inert gas, the perovskite solution is dripped on the upper surface of the cleaned substrate and is uniformly coated until the substrate is completely covered, and the uniformity is setThe rotating speed of the glue machine is 9000r/min, and the acceleration is 1500r/min²And spin-coating the perovskite solution on a clean substrate treated by ultraviolet ozone under the condition that the spin-coating time is 60 s. When the concentration of the perovskite solution is 0.5M, the perovskite solution contains more solvent, the rotating speed is increased, the solvent is completely volatilized within 60s, the growth of single crystals is promoted, and a necessary foundation is provided for preparing the perovskite single crystals with uniform sizes.

And after the spin coating is finished, annealing the spin-coated substrate in a nitrogen atmosphere with water and oxygen content less than 0.01ppm at the annealing temperature of 30 ℃ for 5min to finally obtain the wafer-shaped perovskite single crystal. Annealing at 30 ℃ will further improve the crystal structure that has grown out, resulting in fewer surface defects of the perovskite single crystal.

As shown in fig. 5, which is a microstructure diagram observed by a scanning electron microscope in this example, it is understood from the microstructure diagram that the perovskite single crystal prepared by this method is in a wafer shape, and the shape of all the single crystals is regular and uniform, and the size of the single crystal is smaller than that of the single crystal obtained in example 1.

Example 3

Specifically, the methylamine halide MAX is MABr, and the lead halide PbX is₂Is PbBr₂(ii) a The MABr and PbBr₂The mass of (A) is 0.112g and 0.367g respectively; the MABr and PbBr are added₂And mixing, dissolving in 0.55mL of DMF solvent, adding a stirrer, and stirring at 70 ℃ for 12h for fully mixing to obtain the perovskite solution, wherein the concentration of the perovskite solution is 1.8M. Stirring and mixing at 70 ℃ to facilitate the MABr and PbBr₂Diffusion in DMF solvent resulted in a homogeneous solution of the perovskite.

Providing a substrate, sequentially ultrasonically cleaning the substrate for 40min by using deionized water, acetone, isopropanol and ethanol, drying by using nitrogen, and treating the substrate for 30min by using ultraviolet ozone after drying and before spin coating.

Under the protection of inert gas, dropwise adding the perovskite solution on the cleaned substrate and uniformly coating the perovskite solution on the substrate, and arrangingThe rotating speed of the spin coater is 3000r/min, and the acceleration is 1500r/min²And spin-coating the perovskite solution on a clean substrate treated by ultraviolet ozone under the condition that the spin-coating time is 60 s.

And after the spin coating is finished, annealing the spin-coated substrate in a nitrogen atmosphere with the water and oxygen content less than 0.01ppm at the annealing temperature of 30 ℃ for 5min, and finally preparing the wafer-shaped perovskite single crystal. Annealing at 30 ℃ will further improve the crystal structure that has grown out, resulting in a reduction of surface defects of the perovskite single crystal.

As shown in fig. 6, which is a microstructure diagram observed by a scanning electron microscope in this example, it is understood from the microstructure diagram that the perovskite single crystal produced by this method is in a wafer shape, and the morphology of all the single crystals is regular and uniform, and the single crystal size thereof is larger than that of the single crystal obtained in example 1.

In summary, the invention provides a preparation method of a wafer-shaped perovskite single crystal, which comprises the steps of mixing methylamine halide and lead halide, dissolving the mixture in an organic solvent, and then heating the mixture under the condition of stirring to obtain a perovskite solution, wherein the concentration of the perovskite solution is 0.5-1.8M; and then spin-coating the perovskite solution on a substrate at the rotating speed of 3000r/min-9000r/min to prepare the disk-shaped perovskite single crystal. Uniformly coating the perovskite solution on the substrate by using centrifugal force generated during rotation, and forming supersaturated solution along with the volatilization of the solvent, wherein the perovskite single crystal begins to be separated out; the growth of single crystals in different shapes can be regulated and controlled and perovskite materials with different sizes can be prepared by matching the concentration of the solution with the rotating speed. The preparation method of the wafer-shaped perovskite single crystal is simple, samples grown on the substrate are regular in structure and uniform in appearance and are all in a wafer shape, and the surface roughness of the obtained perovskite single crystal material is low.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.