Preparation method of convex single crystal rod

Abstract

The invention belongs to the field of new semiconductor materials, and particularly relates to a preparation method of a convex single crystal rod, which comprises the following steps: completely dissolving a semiconductor crystal compound precursor with a certain concentration in a solvent to obtain a clear and transparent precursor solution, injecting the obtained precursor solution into a flexible tube, and carrying out vacuum drying to obtain the convex single crystal rod. The method comprises the following steps: sealing two ends of a tube to prevent a precursor solution from leaking outwards, then standing at a proper growth temperature, obtaining a convex single crystal rod in which a flexible tube grows in a limited range after a certain growth time, putting the flexible tube with the convex single crystal rod into a non-polar solvent to swell the flexible tube, and enabling the convex single crystal rod to naturally fall off from the flexible tube, thereby obtaining the convex single crystal rod. And the convex single crystal rod with low interface defects and high quality is obtained. Compared with traditional methods such as mechanical cutting. The method is simple in preparation process and high in yield, and the prepared single crystal rod has a unique light capture structure and has excellent photoelectric properties.

Description

Technical Field

[0001] The present invention belongs to the field of new semiconductor materials, and relates to a method for preparing a convex single crystal rod, in particular to a method for growing a high-quality perovskite single crystal rod with a wide applicable range, adjustable diameter of the convex single crystal rod and controllable length. Background Art

[0002] The characteristics of convex semiconductor materials are mainly reflected in their surface morphology and various physical property changes brought about thereby. Convex refers to the shape in which the surface of the semiconductor material bulges outward. For optoelectronic devices, the surface bulge affects optical properties such as light reflection, refraction and scattering. Compared with planar semiconductor devices, single crystal rods with a convex morphology have natural surface advantages in the preparation of 3D detection devices. Convex devices are also prone to generate more surface states, and these surface states may affect the transport properties of electrons. Therefore, the control of the surface morphology is of great significance in semiconductor devices.

[0003] It is very difficult to obtain compound semiconductor single crystal rods by mechanical processing due to their low strength, easy fragmentation, easy wear and other disadvantages. There are still some technical barriers that need to be overcome urgently in the existing methods for preparing semiconductor single crystal rods. The high-temperature melting method has high energy consumption and is difficult to control, resulting in uneven crystal growth and many interface defects. Traditional solution methods and vapor deposition methods are easily affected by solvents and impurities, and it is difficult to obtain a crystal rod structure. Semiconductor crystal defects may have a negative impact on optoelectronic properties, especially in convex structures, and the defects may be exacerbated due to morphological changes. Solving the defect problem is crucial for improving the efficiency of photodetectors. So far, there has been no report on a method for preparing a convex single crystal rod with low interface defects by the solution method.

[0004] At present, there are few reports on obtaining semiconductor single crystal rods using physical or chemical methods. Due to the fragility of single crystals, it is very difficult to obtain a regular columnar crystal surface by traditional mechanical cutting methods. The space confinement method is a common method for obtaining special-shaped crystals using a hard substrate. Researchers obtained glass tube / perovskite crystals using a glass tube as a hard template, but it was difficult to remove the glass tube and it was impossible to obtain a convex crystal rod with low defects. For the special convex surface of the single crystal rod, the surface defects caused by peeling the crystal from the hard substrate are irreversible. The method of using a hard template to prepare a convex single crystal rod is not feasible.

[0005] The present invention provides a method for preparing a convex single crystal rod, which uses a flexible interface to limit the growth of the single crystal in a flexible tube to control the diameter and the surface texture microstructure, and then places the flexible tube with the single crystal in a non-polar solvent for a swelling reaction, and uses the microstructure inside the flexible tube and the gentle acting force of the swelling reaction to obtain a convex single crystal rod with high crystallinity. Summary of the Invention

[0006] The present invention aims to overcome some deficiencies in the prior art and provides a method for growing a semiconductor single crystal rod with a complete crystal plane. This method has the characteristics of obtaining high-quality crystals, wide application range, adjustable size, simple operation, and low cost.

[0007] The experimental scheme of the present invention is shown in the following steps:

[0008] A semiconductor crystal compound precursor with a certain concentration is completely dissolved in a solvent to obtain a clear and transparent precursor solution. The obtained precursor solution is injected into a flexible tube, and both ends of the tube are sealed to prevent the precursor solution from leaking out. Then, it is left standing at a suitable growth temperature. After a certain growth time, a convex single crystal rod confined by the flexible tube is obtained. The flexible tube with the convex single crystal rod is placed in a non-polar solvent to cause the flexible tube to swell, and the convex single crystal rod naturally falls off from the flexible tube, obtaining a high-quality convex single crystal rod with low interface defects.

[0009] A method for preparing a convex single crystal rod, characterized in that the cation of the semiconductor crystal compound is an alkylamine ion (CH3(CH2) n NH3+, n = 0 - 8), an alkyldiamine ion (NH3-(CH2) n -NH3) 2 +, n = 3 - 8), an unsaturated amine ion, a formamidinium ion (FA+), a guanidinium ion (GA + ), Li+, Na+, K+, Cs+, Rb+, Ag+, Pb 2 +, Sn 2 +, Zn 2+ , Cu+, Cu 2 +, Bi 3+ , Sb 3+ , Mo 4+ , W 4+ or more than one of them; the anion is Cl - , Br - , I - , SO4 2- , S 2- , PO4 3- or more than one of them.

[0010] A method for preparing a convex single crystal rod, characterized in that the solvent is one or more of N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylethanolamine, γ-butyrolactone, N,N-dibutylethanolamine, N-methylpyrrolidone, acetone, ethanol, and methanol.

[0011] A method for preparing a convex single crystal rod, characterized in that the material of the flexible tube is one or more of silica gel, polybutene, polyethylene, polypropylene, rubber tube, polyvinyl chloride, and polyester composite material.

[0012] A method for preparing a convex single crystal rod, characterized in that the precursor solution of the crystal compound in the flexible tube is affected by gravity, interfacial tension, and concentration gradient, and the solvent evaporation causes the solution to reach saturation, forming crystal seeds and starting to grow.

[0013] A method for preparing a convex single crystal rod, characterized in that the growth time is from 0.01 hour to 1 month, and the growth temperature is between -20°C and 200°C.

[0014] A method for preparing a convex single crystal rod, characterized in that the diameter of the flexible tube is between 0.1 micrometers and 100 centimeters.

[0015] A method for preparing a convex single crystal rod, characterized in that the microstructure of the inner wall of the flexible tube can be one or more of the natural crystalline microstructure, natural amorphous microstructure, and artificial microstructure of the inner wall material of the flexible tube.

[0016] A method for preparing a convex single crystal rod, characterized in that the non-polar solvent is one or more of a saturated liquid alkane solvent, an unsaturated liquid olefin solvent, an unsaturated liquid alkyne solvent, a liquid ether solvent, and a liquid ester solvent.

[0017] Compared with the traditional solution method, the present invention has the following characteristics:

[0018] (1) The flexible tube has the property of selectively permeating solvent molecules and ions. For example, silica gel, polybutene, polyethylene, polypropylene, rubber tubes, polyvinyl chloride, and polyester composites have the characteristic of allowing polar solvent molecules to diffuse out of the tube wall, and the microstructure on the inner wall of the tube in-situ imprints on the crystal to obtain a light-trapping structure. At the same time, the swelling phenomenon occurs with the non-polar solvent, generating a gentle force to separate the crystal from the inner wall of the tube. Compared with the defects generated when the hard substrate is separated from the crystal, the crystallization quality is guaranteed;

[0019] (2) Using the designable microstructure on the inner wall of the flexible tube to achieve in-situ imprinting synthesis of a convex perovskite single crystal rod with a microstructure, improving the light-trapping performance and further improving the optoelectronic response characteristics of the convex single crystal rod device;

[0020] (3) Utilizing the swelling property of the non-polar solvent on the flexible tube to enable the convex single crystal rod to fall off without damage. Description of the Drawings

[0021] Figure 1 Optical microscope image of the flexible tube and the convex single crystal rod

[0022] Figure 2 XRD pattern of the MAPbBr3 convex single crystal rod Specific implementation method

[0024] To make the substantial features and practical applicability of the present invention more easily understandable, the technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and several specific embodiments. However, the following description and explanation of the embodiments do not constitute any limitation to the protection scope of the present invention. Any equivalent transformation or substitution in terms of function, method, or structure made by those of ordinary skill in the art according to these embodiments shall fall within the protection scope of the present invention:

[0025] Example 1

[0026] Experimental steps for MAPbBr3 convex single crystal rods:

[0027] (1) Methylammonium bromide and lead bromide are dissolved in N,N-dimethylformamide in a molar ratio of 1:1, stirred for 8 h, and filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a clear and transparent MAPbBr3 precursor solution;

[0028] (2) Appropriate amount of MAPbBr3 precursor solution is taken with a pipette and slowly injected into a silica gel tube, and both ends of the silica gel tube are sealed;

[0029] (3) The above silica gel tube is placed in a 25° drying oven and left standing for 7 days, and MAPbBr3 convex single crystal rods grow inside the silica gel tube;

[0030] (4) After the single crystal growth is completed, it is taken out of the drying oven, and then the silica gel tube is placed in dodecane and left standing for 5 - 10 minutes. After the silica gel tube swells, MAPbBr3 convex single crystal rods are obtained.

[0031] Example 2

[0032] Experimental steps for FASnCl3 convex single crystal rods:

[0033] (1) Formamidinium chloride and tin chloride are dissolved in dimethyl sulfoxide in a molar ratio of 1:1, stirred for 6 h, and filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a clear and transparent FASnCl3 precursor solution;

[0034] (2) Appropriate amount of FASnCl3 precursor solution is taken with a pipette and slowly injected into a polybutene tube, and both ends of the polybutene tube are sealed;

[0035] (3) The above polybutene tube is placed in a 40° drying oven and left standing for 10 days, and convex single crystal rods grow inside the polybutene tube;

[0036] (4) After the single crystal growth is completed, it is taken out of the drying oven, and then the polybutene tube is placed in acetylene solution and left standing for 10 - 15 minutes. After the polybutene tube swells, FASnCl3 convex single crystal rods are obtained.

[0037] Example 3

[0038] Experimental steps for NaZnI3 convex single crystal rod:

[0039] (1) Sodium iodide and zinc iodide are dissolved in ethanol in a molar ratio of 1:1, stirred for 12 h, and filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a clear and transparent NaZnI3 precursor solution;

[0040] (2) Take an appropriate amount of NaZnI3 precursor solution with a pipette, slowly inject it into a polyvinyl chloride tube, and seal both ends of the polyvinyl chloride tube;

[0041] (3) Place the above polyvinyl chloride tube in a 60° drying oven and let it stand for 8 days, and convex single crystal rods grow inside the polyvinyl chloride tube;

[0042] (4) Take out the grown single crystal from the drying oven, then place the polyvinyl chloride tube in decane and let it stand for 10 - 15 minutes. After the polyvinyl chloride tube swells, obtain the NaZnI3 convex single crystal rod.

[0043] Example 4

[0044] Experimental steps for CsCuBr3 convex single crystal rod:

[0045] (1) Cesium bromide and copper bromide are dissolved in N,N - dimethylformamide in a molar ratio of 1:1, stirred for 7 h, and filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a clear and transparent CsCuBr3 precursor solution;

[0046] (2) Take an appropriate amount of CsCuBr3 precursor solution with a pipette, slowly inject it into a polyethylene tube, and seal both ends of the polyethylene tube;

[0047] (3) Place the above polyethylene tube in a 30° drying oven and let it stand for 10 days, and convex single crystal rods grow inside the polyethylene tube;

[0048] (4) Take out the grown single crystal from the drying oven, then place the polyethylene tube in an ether solution and let it stand for 15 - 20 minutes. After the polyethylene tube swells, obtain the CsCuBr3 convex single crystal rod.

[0049] Example 5

[0050] Experimental steps for AgBiCl4 convex single crystal rod:

[0051] (1) Silver chloride and bismuth chloride are dissolved in N,N - dimethylethanolamine in a molar ratio of 1:1, stirred for 8 h, and filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a clear and transparent AgBiI4 precursor solution;

[0052] (2) Use a pipette to take an appropriate amount of AgBiCl4 precursor solution, slowly inject it into a polypropylene tube, and seal both ends of the polypropylene tube;

[0053] (3) Place the above polypropylene tube in a 40°C drying oven and let it stand for 25 days to grow convex single crystal rods inside the polypropylene tube;

[0054] (4) Take out the grown single crystal from the glove box, then place the polypropylene tube in n-hexane and let it stand for 10 - 15 minutes. After the polypropylene tube swells, obtain AgBiCl4 convex single crystal rods.

[0055] Example 6

[0056] Experimental steps for CsAg2I3 convex single crystal rods:

[0057] (1) Cesium iodide and silver iodide are dissolved in dimethyl sulfoxide in a molar ratio of 1:2, stirred for 11 h, and filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a clear and transparent CsAg2I3 precursor solution;

[0058] (2) Use a pipette to take an appropriate amount of perovskite precursor solution, slowly inject it into a rubber tube, and seal both ends of the rubber tube;

[0059] (3) Place the above rubber tube in a 35°C drying oven and let it stand for 6 days to grow convex single crystal rods inside the rubber tube;

[0060] (4) Take out the grown single crystal from the glove box, then place the rubber tube in methyl ether solution and let it stand for 15 - 25 minutes. After the rubber tube swells, obtain CsAg2I3 convex single crystal rods.

[0061] Example 7

[0062] Experimental steps for FAPbCl3 convex single crystal rods:

[0063] (1) Formamidinium chloride and lead chloride are dissolved in acetone in a molar ratio of 1:1, stirred for 8 h, and filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a clear and transparent FAPbCl3 precursor solution;

[0064] (2) Use a pipette to take an appropriate amount of FAPbCl3 precursor solution, slowly inject it into a polybutene tube, and seal both ends of the polybutene tube;

[0065] (3) Place the above polybutene tube in a 60°C drying oven and let it stand for 4 days to grow convex single crystal rods inside the polybutene tube;

[0066] (4) Take out the grown single crystal from the drying oven, then place the polybutene tube in hexadecane and let it stand still for 15 - 25 minutes. After the polybutene tube swells, a FAPbCl3 convex single crystal rod is obtained.

[0067] Example 8

[0068] Experimental steps for CsCu2I3 convex single crystal rod:

[0069] (1) Cesium iodide and cuprous iodide are dissolved in N-methylpyrrolidone according to a molar ratio of 1:2, stirred for 12 h, and filtered through a 0.22 μm polytetrafluoroethylene filter to obtain a clear and transparent CsCu2I3 precursor solution.

[0070] (2) Use a pipette to take an appropriate amount of CsCu2I3 precursor solution, slowly inject it into the silica gel tube, and seal both ends of the silica gel tube.

[0071] (3) Place the above silica gel tube in a 50° drying oven and let it stand still for 7 days, and a convex single crystal rod grows inside the silica gel tube.

[0072] (4) Take out the grown single crystal from the drying oven, then place the silica gel tube in ethyl butyrate and let it stand still for 10 - 15 minutes. After the silica gel tube swells, a CsCu2I3 convex single crystal rod is obtained.

[0073] Example 9

[0074] (BA)2MAPb2Br7 convex single crystal rod experimental steps:

[0075] (1) Butylamine bromide, methylammonium bromide, and lead bromide are dissolved in γ-butyrolactone according to a ratio of 2:1:2 to obtain a clear and transparent (BA)2MAPb2Br7 precursor solution.

[0076] (2) Use a pipette to take an appropriate amount of (BA)2MAPb2Br7 precursor solution, slowly inject it into the polyethylene tube, and seal both ends of the polyethylene tube.

[0077] (3) Place the above polyethylene tube in a 45° drying oven and let it stand still for 2 days, and a convex single crystal rod grows inside the polyethylene tube.

[0078] (4) Take out the grown single crystal from the drying oven, then place the polyethylene tube in decane and let it stand still for 20 - 25 minutes. After the polyethylene tube swells, a (BA)2MAPb2Br7 convex single crystal rod is obtained.

[0079] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for preparing a convex single crystal rod, characterized in that, A high-quality convex single crystal rod is prepared by taking advantage of the characteristic that solvent molecules can diffuse through the flexible tube wall while solutes cannot. By designing the microstructure of the inner wall of the flexible tube with different structures, a high-quality convex single crystal rod with an in-situ imprinted structure on the surface is further obtained. It includes the following steps: completely dissolve a semiconductor crystal compound precursor with a certain concentration in a solvent to obtain a clear and transparent precursor solution, inject the obtained precursor solution into a flexible tube, seal both ends of the tube to prevent the precursor solution from leaking outwards, then let it stand at a suitable growth temperature, and after a certain growth time, a convex single crystal rod confined by the flexible tube is obtained. Place the flexible tube with the convex single crystal rod in a non-polar solvent to swell the flexible tube, and let the convex single crystal rod naturally fall off from the flexible tube to obtain a high-quality convex single crystal rod with low interface defects.

2. The preparation method of a convex single crystal rod according to claim 1, wherein The cation of the described semiconductor crystal compound is an alkylamine ion (CH3(CH2) n NH3+, n = 0 - 8), an alkyldiamine ion (NH3-(CH2) n -NH3) 2 +, n = 3 - 8), an unsaturated amine ion, a formamidinium ion (FA+), a guanidinium ion (GA + ), Li+, Na+, K+, Cs+, Rb+, Ag+, Pb 2 +, Sn 2 +, Zn 2+ , Cu+, Cu 2 +, Bi 3+ , Sb 3+ , Mo 4+ , W 4+ or more than one of them; the anion is Cl - , Br - , I - , SO4 2- , S 2- , PO4 3- or more than one of them.

3. The preparation method of a convex single crystal rod as claimed in claim 1, characterized in that The solvent is one or more of N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylethanolamine, γ-butyrolactone, N,N-dibutylethanolamine, N-methylpyrrolidone, acetone, ethanol, and methanol.

4. The preparation method of a convex single crystal rod according to claim 1, characterized in that The flexible tube is made of one or more of silica gel, polybutene, polyethylene, polypropylene, rubber tube, polyvinyl chloride, and polyester composite material.

5. The preparation method of a convex single crystal rod according to claim 1, wherein, The crystal compound precursor solution in the flexible tube is affected by gravity, interfacial tension, and concentration gradient. After the solvent evaporates to make the solution reach saturation, crystal seeds are formed and growth begins.

6. The preparation method of a convex single crystal rod according to claim 1, characterized in that, The growth time is from 0.01 hour to 1 month, and the growth temperature is between -20°C and 200°C.

7. The preparation method of a convex single crystal rod according to claim 1, characterized in that, The diameter of the flexible tube is between 0.1 micrometer and 100 centimeters.

8. The preparation method of a convex single crystal rod according to claim 1, characterized in that, The microstructure of the inner wall of the flexible tube can be one or more of the natural crystalline microstructure, natural amorphous microstructure, and artificial microstructure of the flexible tube inner wall material.

9. The preparation method of a convex single crystal rod according to claim 1, wherein The non-polar solvent is one or more of saturated liquid alkane solvents, unsaturated liquid alkene solvents, unsaturated liquid alkyne solvents, liquid ether solvents, and liquid ester solvents.

Images