A kind of monocrystalline silicon etching texturing additive and its application

Abstract

The invention belongs to silicon wafer texturing technology, in particular to a monocrystalline silicon etching texturing additive and its application. Konjac glucomannan of a specific type and specific molecular weight is selected as an additive and added to the lye to prepare the texturing liquid, and it is compounded with surfactants, ascorbic acid, sodium hydroxide, acetylene glycol, sodium sulfonate, and flocculants , to obtain monocrystalline silicon etching texturing liquid, and use this texturing liquid to process monocrystalline silicon, which can not only reduce the amount of alkali solution, but also avoid the damage to the regularity of the silicon wafer surface, and can effectively reduce the exposure to light. reflection to improve the photoelectric conversion efficiency of the assembled solar cells.

Description

Technical field [0001] The present invention belongs to the field of solar cell production flannel process technology, relates to a monocrystalline silicon fleece additive and the formulation of a fleece liquid. Background [0002] At present, the process flow of conventional silicon solar cell production is surface pre-cleaning, fleece removal of damage layer and formation of anti-reflective suede structure, chemical cleaning and drying; the formation of uniformly doped PN junctions at each point on the surface of the silicon wafer by liquid source diffusion; the removal of peripheral PN junctions and surface phosphorus-silicon glass formed during the diffusion process; the surface deposition passivation and anti-reflective film; the production of the back electrode, the back electric field and the front electrode of the solar cell; the sintering to form ohmic contact, thereby completing the production process of the entire cell. Among them, the step of removing the damage layer...

AI Technical Summary

Problems solved by technology

Its disadvantages are: long time for texturing, large and uneven texturing pyramid, high requirements for the surface state of the original silicon wafer, relatively large chemical consumption, short solution life, poor texturing repeatability, and volatile amount of isopropanol, etc. It is very large, needs to be adjusted continuously, and the operation is difficult, which leads to problems such as high defect rate of texturing appearance and low conversion efficiency of cells

[0004] At present, the size of the pyramid-shaped hillocks obtained after the use of traditional monocrystalline silicon etching and texturing additives can be controlled to only 2-4 μm, which makes it difficult to further reduce the size and increase the density of pyramid-shaped hillocks.

The pyramid-shaped square cone structure on the surface can reflect light multiple times, which not only reduces the reflection loss, but also changes the direction of light in the silicon wafer, prolongs the optical path, and increases the output of photogenerated carriers. The reduction of the reflectivity of the suede surface is conducive to the improvement of the photoelectric conversion performance of the battery, and the surface reflectance of the current suede surface can only reach 10-14%, which is not conducive to the further improvement of the photoelectric conversion rate of the solar cell. The amount of alkali in the cashmere liquid is relatively large, which is not conducive to environmental protection