Wet sandblasting pretreatment of diamond wire sawn multi-crystalline silicon wafer for surface acid texturization in photovoltaics

As the substrate of photovoltaic solar cells, multi-crystalline silicon (mc-Si) wafers cut by diamond wire saw are less effective in commercial acid texturing, due to the saw marks and amorphous silicon layer on the as-sawn wafer surface. This paper proposes to wet sandblasting process for surface modification of diamond wire sawn mc-Si wafers before acid texturing to solve this problem. The effect of wet sandblasting modification on the surface morphology of mc-Si wafers was analyzed, as well as the surface morphology and anti-reflection performance of mc-Si wafers after wet acid etching were studied. The results show that the saw marks and amorphous silicon layer on the surface of as-sawn mc-Si wafer can be effectively removed by wet sandblasting with appropriate processing parameters. The reflectivity of pretreated mc-Si wafers after acid texturing is significantly lower than that of the unpretreated ones, which can meet the production requirements of solar photovoltaic cells. The research results provide a research idea to promote the effective combination of diamond wire saw slicing mc-Si and commercial acid texturing process.