Monocrystalline silicon wafer alcohol-free texturing process and texturing additive

Abstract

The invention relates to a monocrystalline silicon wafer alcohol-free texturing process and a texturing additive. Firstly, a silicon wafer is placed in preprocessing liquid so as to be preprocessed for 60 s to 300 s, and the silicon wafer is then placed in texturing liquid for texturing. The monocrystalline silicon texturing process includes the steps that deionized water is heated to 70 DEG C to 90 DEG C, sodium hydroxide or potassium hydroxide is added, and monocrystalline silicon texturing corrosive liquid is acquired. When the texturing additive is adopted for texturing, isopropanol or ethyl alcohol is not needed, tiny, even and dense pyramid texturing faces can be acquired, texturing cost is reduced, and environmental pollution is avoided. The preprocessing process is added before the texturing step, the silicon wafer acquired after texturing can be cleaner, rework caused by white spot fingerprints and the like can be reduced, and certain practical value is achieved.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to an alcohol-free texturing process for monocrystalline silicon wafers and a texturing additive thereof. Background technique [0002] In the process of solar cell preparation, in order to improve the efficiency of solar cells, it is necessary to make a textured surface on the surface of the single crystal silicon wafer. The effective textured structure can make the incident sunlight form secondary reflection or multiple reflections on the surface of the silicon wafer, increasing the light intensity. The utilization rate makes more photons be absorbed in the area near the pn junction to generate photo-generated carriers, and these photo-generated carriers are easier to be collected, thus increasing the collection efficiency of photo-generated carriers. [0003] Conventional texturing process generally uses sodium hydroxide or potassium hydroxide, adding appropriate mixed solution of isop...

AI Technical Summary

Problems solved by technology

Its disadvantages are: non-uniform texturing pyramid, high requirements on the surface state of the original silicon wafer, relatively large chemical consumption, difficult control of the texturing process, large volatilization of isopropanol, etc., need to continuously adjust liquid, and difficult operation. As a result, the rework rate of the textured appearance is very high, and the conversion rate of the cell is low.

Although the above two additives do not need to add isopropanol, which reduces the COD of the velvet waste liquid and reduces the cost of velvet, but there are high proportions of white spots and fingerprints on the velvet surface after velvet making, and the appearance of the velvet surface is relatively high. unclean problem