A crystalline silicon texturing process based on laser interference-induced reaction

Abstract

The invention belongs to the technical field of a solar battery, in particular to a wool preparing process by crystalline silicon based on laser interference induced reaction, which comprises the following steps of: (1) corrosion treatment: corroding a silicon wafer to remove mechanical damage on the surface; (2) placing the silicon wafer in an alkaline solution with a certain concentration at room temperature; (3) locally heating the crystalline silicon wafer dipped in strong base solution by laser; and (4) forming a wool face: scanning the whole silicon wafer by interference laser till an uniform wool face is formed on the surface of the silicon wafer. The wool preparing process is free from a laser with over-high power, and saves the energy sources and the machining cost. The process is controlled within an optical spot and has less affect the silicon wafer in other positions. In addition, the preparing process is simple, convenient and rapid. No toxic gases are generated in the wool preparing process, and adverse effects on health of workers and environment are avoided. The wool preparing process by crystalline silicon based on laser interference induced reaction, provided by the invention, can enhance the speed of the process greatly, has good industrialized prospect, and improves the efficiency of the battery extremely.

Description

technical field [0001] The invention belongs to solar photovoltaic applications, in particular to a crystalline silicon texturing process based on laser interference induced reaction. Background technique [0002] The preparation of the textured surface on the surface of the solar cell can effectively reduce the reflection of the solar cell to sunlight, thereby improving the efficiency of the solar cell. [0003] At present, the commonly used texturing process in polycrystalline silicon solar cells is to corrode polycrystalline silicon wafers in a specific ratio of HF / HNO3 solution to form oval or silkworm-shaped corrosion pits on the surface of silicon wafers, thereby reducing the reflection of light, but this method The reflectivity of the prepared crystalline silicon wafer is as high as 20%, which is much higher than that of the pyramid-shaped suede surface prepared by anisotropic etching of single crystal silicon wafer by sodium hydroxide, which is also an important reas...

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Problems solved by technology

[0006] It can be seen that strong alkali solutions such as sodium hydroxide or potassium hydroxide react with silicon and no toxic gas is released. At the same time, the treatment of this type of waste liquid is relatively easy, and it is not easy to pollute the environment. However, the corrosion of silicon by this type of strong alkali solution is anisotropic Heterotropic, can only form pyramid-shaped suede on the silicon wafer with (100) crystal orientation, but cannot form effective anti-reflection structure at the grains of other crystal orientations, so it is not possible to directly prepare polysilicon with strong alkali solution piece of suede

[0007] Most of the existing laser texturing processes use laser to directly scan the surface and engrave grooves. The width of the textured surface prepared by this process is greater than 20 μm, so the depth of the groove needs to reach more than 20 μm to have better anti-reflection performance, but this brings subsequent batteries. High fragmentation rate in the production process

At the same time, due to the high-temperature laser treatment process, a large number of defects are generated on the surface of the silicon wafer, forming defect centers, which makes it difficult to improve the efficiency of the battery in this process.

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