Periodically patterned Si pyramids for realizing high efficient solar cells by wet etching process

•Periodic Si structures were designed for a high-efficient solar cell.•Electrically conductive and optically transparent ITO film was coated onto Si.•ITO-coated Si patterns were effective for carrier collection.•Wet-processed Si solar cell is effective to enhance current and efficiency.

Periodic Si structures were designed for a high-efficient solar cell. Wet-etching method was applied to tailor the light-absorbing Si substrate to periodic patterns. Electrical conductor of a thin indium-tin-oxide (ITO) layer was coated onto the patterned Si structures as an anti-reflection coating layer, which effectively reduces the light-reflection at a surface. Due to the optical end electrical benefits of an ITO layer, the periodic Si solar cell provided much improved current density of 36.28 mA/cm2 with a conversion efficiency of 16.3%. For quantum efficiencies, this ITO-coated periodic Si structure solar cell is enormously effective to improve long-wavelength photons. This study reveals that efficiency of solar cells could be readily enhanced via large-scale available wet-etching processes with an electrical conductive ITO coating method.