Industrial Applicability of Antireflection-Coating-Free Black Silicon on PERC Solar Cells and Modules

Black silicon (b-Si) is of particular interest within the photovoltaic community due to its ability to texture diamond wire-sawn multicrystalline silicon wafers. In this work, we apply a deep dry-etched black silicon nanotexture, which possesses less than 1 % solar-weighted reflectance with no antireflection coating (ARC), to industrial Passivated Emitter and Rear Cells (PERC). Additionally, the cells are processed further into small solar modules, which are characterized by their electrical and optical performance. The fragile nanostructures remain intact during industrial cell and module fabrication, maintaining the excellent optical properties until the final product. We show that b-Si modules with a typical cover glass retain their performance until incident angles larger than 60°, whereas the heavily increased reflectance of acidic-textured modules decreases their efficiency already after a 30° tilt. Furthermore, at an incidence angle of 70°, the efficiency of b-Si modules has reduced only 7 %, while that of the acidic-textured equivalents has decreased more than 25 %. Hence, the excellent optical properties of ARC-free b-Si are maintained also at module level. The results demonstrate that deep dry-etched b-Si nanostructures are fully applicable to current industrial PERC production facilities.