Novel non-metallic non-acidic approach to generate sub-wavelength surface structures for inline-diffused multicrystalline silicon wafer solar cells

Based on a combination of RIE nano-texturing and the conventional micro-texturing processes, an improved double-texturing process is reported. This paper explains its successful implementation using low-cost inline-diffusion and non-acidic 'SERIS etch' etch-back technology and elimination of any RIE-related damage removal etching step. This optimised double-textured post-diffused SWS surface does not affect minority carrier lifetime and has WAR of 3.2% after SiNx ARC deposition, which is significantly lower than that of conventional acidic-textured (WAR of 6-7%) 156 mm2, industrial-grade, p-type multi-Si wafers. SEM micrographs of the double-textured SWS multi-Si surface: (a) magnification: 15000×, (b) magnification: 35000×. Left: front surface reflectance as a function of wavelength for double and micro-textured multi-Si wafers before and after SiNx ARC deposition.