Machining treatment method for metal halide perovskite single crystal

Abstract

The present application relates to the technical field of the preparation of perovskite single crystals, and more specifically relates to a machining treatment method for a metal halide perovskite single crystal. The metal halide perovskite single crystal is a metal halide perovskite material, the chemical structural formula of the metal halide perovskite material being ABX3. The method comprises: subjecting the metal halide perovskite single crystal to wire cutting, grinding and polishing, and polishing the metal halide perovskite single crystal by utilizing a polishing paste and diamond oil. Moreover, without any damage to the surface of the perovskite single crystal and the charge collection efficiency of the perovskite single crystal, the requirement for the surface roughness of the perovskite single crystal during machining is met, and therefore the performance of a corresponding photovoltaic device is improved without any increase in the preparation difficulty of surface polishing of the perovskite single crystal.

Description

A mechanical processing method for metal halide perovskite single crystal Technical Field

[0001] The present application relates to the technical field of perovskite single crystal preparation, and more specifically, to a mechanical processing method for metal halide perovskite single crystal. Background Art

[0002] Peptide and protein drugs have become a new class of active pharmaceutical ingredients due to their excellent selectivity and low toxicity. For example, antimicrobial peptides possess both antimicrobial and antitumor properties. Most antitumor peptides are derived from antimicrobial peptides (AMPs). Originally discovered in insects, amphibians, and plants, they help defend hosts against pathogens, thereby preventing and controlling diseases or pests. Specific peptide structures are formed when clusters of hydrophobic and cationic amino acids are arranged in discrete sections of the molecule.

[0003] In recent years, studies on a large number of natural peptides have shown that these natural peptides also have certain anti-cancer activity and can therefore become one of the effective ingredients for cancer treatment. For example, ant peptide is a natural antimicrobial peptide and anti-tumor peptide. Its amino acid sequence is the linear amino acid sequence found in ant venom. It has antimicrobial and anti-cancer activities, can destroy cell membranes, inhibit mitochondrial activity, regulate the gene expression of Bax, Caspase-3 and Bcl-2 proteins, and then induce cell apoptosis. Therefore, it has the potential to be used as a cancer treatment drug. However, anti-tumor peptides may also induce hemolysis of normal cells, and this disadvantage may affect clinical application. Therefore, it is necessary to select suitable nanocarriers to load such active ingredients of drugs to enhance drug activity, reduce adverse side effects, and make them better for clinical application.

[0004] The shortcomings of the existing technology mainly include:

[0005] (1) The current perovskite single crystal cutting technology uses blade cutting and cannot cut metal halide perovskite single crystals with adjustable flatness;

[0006] (2) The polishing method in the prior art only uses coarse sandpaper for polishing, and cannot control the surface roughness of the perovskite single crystal, so it is difficult to achieve uniform photoelectric properties for the top interface;

[0007] (3) The current high-performance perovskite single crystals can only be grown with fixed specifications and cannot process the perovskite single crystals that have been prepared. Therefore, the existing technology is difficult to be compatible with the current application of perovskite single crystals in the optoelectronic field.

[0008] The mechanical cutting process of metal halide perovskite single crystals can lead to microscopic defects such as microcracks and bubbles, as well as insufficient component uniformity and lower chemical stability compared to inorganic photovoltaic materials such as silicon, CdTe, GaAs, and CIGS. This results in insufficient uniformity in the optoelectronic properties of mechanically processed perovskite single crystals and difficulty in modifying bottom interface defect states, which in turn affects the performance and industrialization of perovskite single crystals.

[0009] Summary of the Invention

[0010] The present disclosure provides a method for mechanical processing of metal halide perovskite single crystals, which solves the surface roughness requirements of perovskite single crystals during mechanical processing without damaging the surface of the perovskite single crystals and the charge collection efficiency of the perovskite single crystals, thereby improving the performance of corresponding photovoltaic devices without increasing the difficulty of preparing the surface polishing of the perovskite single crystals.

[0011] The present disclosure provides a method for wire cutting of a metal halide perovskite single crystal. The metal halide perovskite single crystal is a metal halide perovskite material having a chemical structural formula of ABX3, wherein A is an organic or inorganic cation such as methylamine (MA), formamidine (FA), or cesium (Cs), B is a metal cation such as lead (Pb) or tin (Sn), and X is a halogen or pseudohalogen anion such as iodine (I), bromine (Br), or thiocyanate (SCN). The method comprises wire cutting, grinding, and polishing the metal halide perovskite single crystal, and polishing the metal halide perovskite single crystal using polishing paste and diamond oil.

[0012] Preferably, the wire cutting method is: using a wire cutting machine loaded with 0.15mm diamond wire to precisely cut the metal halide perovskite single crystal, and then using 2000# and 5000# sandpaper for mechanical polishing respectively, applying polishing paste to the polished single crystal, and then fine polishing, applying diamond oil on a 3M polishing cloth to perform the final polishing of the perovskite single crystal after fine polishing, and washing the polished perovskite single crystal with anhydrous ethyl acetate before use.

[0013] Preferably, the method specifically includes the following preparation steps:

[0014] 1) Independently design and build wire cutting platform;

[0015] 2) Self-designed 3M polishing cloth with diamond oil polishing platform;

[0016] 3) Place the cleaned glass on the prepared wire cutting platform iron plate and wait until the glass is firmly attached before use;

[0017] 4) Place the iron plate with the glass on a hot plate and heat it to 100°C. Place paraffin wax with a higher melting point on the glass substrate, spread it evenly, and wait until the paraffin is completely melted and transparent before removing the large piece of paraffin wax solid.

[0018] 5) Place the prepared metal halide perovskite single crystal horizontally on a glass substrate evenly coated with paraffin wax, using a spirit level to maintain levelness to reduce mechanical errors. At this time, cool the hot plate from 100°C to room temperature.

[0019] 6) After the hot plate cools down to room temperature and the color of the paraffin wax changes from transparent to white, use heat-insulating gloves to remove the wire cutting platform iron plate and place it on a horizontal heat-insulating table for later use;

[0020] 7) Place the iron plate with the metal halide perovskite single crystal vertically on a self-built wire cutting platform, take a 0.15mm diamond wire, place it on the roller, adjust the wire cutting parameters and then wire cut the perovskite single crystal.

[0021] Preferably, the specific polishing experiment operation steps are as follows:

[0022] S1: Collect naturally cut perovskite single crystal wafers and clean the surface with anhydrous ethyl acetate;

[0023] S2: Place the perovskite single crystal on the 3M polishing cloth and polish the surface with 2000# and 5000# sandpaper respectively. After removing the raised single crystal particles on the surface, use a cotton swab dipped in anhydrous ethyl acetate to clean the single crystal surface again.

[0024] S3: Apply polishing paste evenly to the surface of the polished perovskite single crystal. Use a small polishing machine with a wool polishing pad to polish at the first power setting. After the gray polishing paste on the surface is completely removed, use a step profiler to measure the roughness.

[0025] S4: Drop the prepared diamond oil on the 3M polishing cloth, use the rough-polished perovskite single crystal for fine polishing, remove the single crystal after it becomes transparent, use a cotton swab dipped in anhydrous ethyl acetate to clean the surface of the single crystal, and use a step profiler to measure the roughness.

[0026] Preferably, the wire cutting method is used for mechanical polishing and single crystal wire cutting of an organic ammonium salt, wherein the organic ammonium salt comprises one of MAPbBr3 or FAPbBr3.

[0027] Preferably, the metal halide perovskite single crystal is polished by a gradient polishing method.

[0028] Preferably, the perovskite single crystal wire cutting preparation process regulates the roughness of the perovskite single crystal by adjusting the thickness of the cutting wire.

[0029] In summary, this application has the following beneficial effects:

[0030] 1. Since the present application is compatible with the metal halide perovskite single crystal cutting and polishing process, the preparation method is simpler and more efficient, and has lower equipment requirements;

[0031] 2. In this application, the wire cutting machine is used to change the wire cutting line width to solve the roughness requirement of the metal halide perovskite single crystal, which significantly improves the yield rate of the overall perovskite single crystal;

[0032] 3. This application is applicable to a variety of hardness metal halide perovskite single crystal materials and can be well used with current perovskite single crystal X-ray detectors.

[0033] It should be understood that the foregoing general description and the following detailed description are merely exemplary and explanatory and are not intended to limit the scope of protection of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a wire cutting platform independently designed and built by this applicant;

[0035] Figure 2 shows the polishing platform with 3M polishing cloth and diamond oil designed by the applicant;

[0036] FIG3 is a diagram of an actual sample before polishing in this application;

[0037] FIG4 is a picture of the actual sample after polishing in this application.

[0038] DETAILED DESCRIPTION

[0039] The present application is further described in detail below with reference to the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions were carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0040] Example

[0041] Example 1

[0042] A method for mechanical processing of perovskite single crystals is provided using a Shenghai SH300 wire cutting machine, 2000# and 5000# sandpaper, 3M polishing cloth, a small polishing machine and other equipment and machines. The method comprises the following steps:

[0043] 1) Independently design and build a wire cutting platform, the schematic diagram is as follows;

[0044] 2) Self-designed 3M polishing cloth with diamond oil polishing platform, the diagram is as follows:

[0045] 3) Place the cleaned glass on the prepared wire cutting platform iron plate and wait until the glass is firmly attached before use;

[0046] 4) Place the iron plate with the glass on a hot plate and heat it to 100°C. Place paraffin wax with a higher melting point on the glass substrate, spread it evenly, and wait until the paraffin is completely melted and transparent before removing the large piece of paraffin wax solid.

[0047] 5) Place the prepared metal halide perovskite single crystal horizontally on a glass substrate evenly coated with paraffin wax, using a spirit level to maintain levelness to reduce mechanical errors. At this time, cool the hot plate from 100°C to room temperature.

[0048] 6) After the hot plate cools down to room temperature and the color of the paraffin wax changes from transparent to white, use heat-insulating gloves to remove the wire cutting platform iron plate and place it on a horizontal heat-insulating table for later use;

[0049] 7) Place the iron plate with the metal halide perovskite single crystal vertically on a self-built wire cutting platform, take a 0.15mm diamond wire, place it on the roller, adjust the wire cutting parameters and then wire cut the perovskite single crystal.

[0050] 8) Collect the naturally cut perovskite single crystal wafers and clean the surface with anhydrous ethyl acetate. The purity of the anhydrous ethyl acetate is 99.95%.

[0051] 9) Place the perovskite single crystal on the 3M polishing cloth and polish the surface using 2000# and 5000# sandpaper respectively. After removing the raised single crystal particles on the surface, use a cotton swab dipped in anhydrous ethyl acetate to clean the single crystal surface again. The purity of anhydrous ethyl acetate is 99.95%.

[0052] 10) Evenly apply polishing paste to the surface of the polished perovskite single crystal, and use a small polishing machine with a wool polishing pad to perform polishing at a first power setting. After the gray polishing paste on the surface is completely removed, use a step profiler to measure the roughness.

[0053] 11) Apply the prepared diamond oil to a 3M polishing cloth and perform fine polishing on the rough-polished perovskite single crystal. After the single crystal becomes transparent, remove it and clean the surface of the single crystal with anhydrous ethyl acetate (99.95% purity) using a cotton swab. Measure the roughness using a step profiler.

[0054] It should be noted that the optimal modified concentrations of the polishing paste and polishing oil in this application are not only applicable to MAPbBr3, an organic metal halide perovskite, but also to most halide perovskite single crystal materials, such as FAPbBr3; the mechanical polishing and single crystal wire cutting in this application can be applied to the production of most perovskite single crystals, but are not only applicable to the single crystal perovskite preparation process, but can also be applied to the preparation of other silicon-based prismatic crystals with higher hardness.

[0055] This application obtained the following conclusions through experiments:

[0056] 1: The actual sample pictures before and after polishing are shown in Figures 3 and 4. The roughness was tested using a step profiler. The roughness was reduced by 60-70%. The step profiler is a Dektakxt step profiler from Platinum Instruments: Model DXT-18-1801.

[0057] 2: This application has counted the yield rate using manual polishing (the yield rate of twenty samples is 50%) and the yield rate using this patented method (the yield rate of twenty samples is 90%). It can be seen that this patented method has greatly improved the experimental yield rate.

[0058] 3: The roughness of different organic ammonium salts was compared and the difference in roughness was within 2%, which meets the experimental error requirements and can be applied to other metal halide perovskite materials.

[0059] The above description is merely an exemplary embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A method for wire sawing of a metal halide perovskite single crystal, characterized in that: The metal halide perovskite single crystal is a metal halide perovskite material, and the chemical structural formula of the metal halide perovskite material is ABX3, wherein A is an organic or inorganic cation of methylamine (MA), formamidine (FA) or cesium (Cs), B is a metal cation of lead (Pb) or tin (Sn), and X is a halogen or pseudohalogen anion of iodine (I), bromine (Br) or thiocyanate (SCN); the method comprises wire cutting, grinding and polishing the metal halide perovskite single crystal, and polishing the metal halide perovskite single crystal using polishing paste and diamond oil.

2. The method for wire sawing of a metal halide perovskite single crystal according to claim 1, characterized in that: The wire cutting method is as follows: using a wire cutting machine loaded with 0.15 mm diamond wire to accurately cut the metal halide perovskite single crystal, and then using 2000# and 5000# sandpaper for mechanical polishing respectively, applying polishing paste to the polished single crystal, and then fine polishing, applying diamond oil on a 3M polishing cloth to perform the final polishing of the perovskite single crystal after fine polishing, and washing the polished perovskite single crystal with anhydrous ethyl acetate before use.

3. The method for wire sawing of a metal halide perovskite single crystal according to claim 1, characterized in that: The preparation steps include: 1) Independently design and build wire cutting platform; 2) Self-designed 3M polishing cloth with diamond oil polishing platform; 3) Select the prepared wire cutting platform iron plate and stick the cleaned glass on it. Wait until the glass is firmly attached before use; 4) Place the iron plate with the glass on a hot plate and heat it to 100°C. Place paraffin wax with a higher melting point on the glass substrate, spread it evenly, wait until the paraffin wax is completely melted and transparent, and then remove the large piece of paraffin wax solid; 5) Place the prepared metal halide perovskite single crystal horizontally on a glass substrate coated with paraffin wax, use a level to keep it level to reduce mechanical errors, and then cool the hot plate from 100°C to room temperature; 6) After the heating platform cools down to room temperature, observe the color of the paraffin wax changes from transparent to white, then use heat-insulating gloves to remove the wire cutting platform iron plate and place it on a horizontal heat-insulating table for later use; 7) Place the iron plate with the metal halide perovskite single crystal vertically on the self-built wire cutting platform, take a 0.15mm diamond wire, place it on the roller, adjust the wire cutting parameters and perform wire cutting on the perovskite single crystal.

4. The method for wire sawing of a metal halide perovskite single crystal according to claim 1, characterized in that: The specific polishing experiment operation steps are as follows: S1: Collect the naturally cut perovskite single crystal wafers and clean the surface with anhydrous ethyl acetate; S2: Place the perovskite single crystal on the 3M polishing cloth and polish the surface with 2000# and 5000# sandpaper respectively. After removing the raised single crystal particles on the surface, use a cotton swab dipped in anhydrous ethyl acetate to clean the single crystal surface again; S3: Evenly apply polishing paste on the surface of the polished perovskite single crystal, use a small polishing machine with a wool polishing pad to perform first-level polishing, and use a step profiler to measure the roughness after the gray polishing paste on the surface is completely removed; S4: Drop the prepared diamond oil on the 3M polishing cloth, use the rough-polished perovskite single crystal for fine polishing, remove the single crystal after it becomes transparent, use a cotton swab dipped in anhydrous ethyl acetate to clean the surface of the single crystal, and use a step profiler to measure the roughness.

5. The method for wire sawing of a metal halide perovskite single crystal according to claim 4, characterized in that: The wire cutting method is used for mechanical polishing and single crystal wire cutting of an organic ammonium salt, wherein the organic ammonium salt comprises one of MAPbBr3 or FAPbBr3.

6. The method for wire sawing of a metal halide perovskite single crystal according to claim 4, characterized in that: The metal halide perovskite single crystal is polished by a gradient polishing method.

7. The method for wire sawing of a metal halide perovskite single crystal according to claim 4, characterized in that: The perovskite single crystal wire cutting preparation process regulates the roughness of the perovskite single crystal by adjusting the thickness of the cutting wire.

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