Fabrication of Silicon Nanowire Arrays by MACE for Effective Light Trapping

Silicon nanowires, in particular, are being actively researched for solar-powered applications because they provide unique ways for converting solar radiation into electrical energy, resulting in highly efficient devices. Due to unique one-dimensional shape, solar cells-based on silicon nanowire (SiNW) arrays have the potential to be cost-effective and efficient sunlight trapping devices. Vertically aligned SiNW’s arrays were fabricated across a large area using metal-assisted chemical etching (MACE) approach that involved etching the silicon substrate in the aqueous hydrofluoric acid (HF) and silver nitrate (AgNO3) solution. This report describes the impact of various etching time at ambient temperature on the length of SiNWs. The time dependency of silicon nanowires growth rate was investigated for p-type substrates at 3 min, 6 min, and 9 min, respectively. In the 400–800 nm wavelength regions, reflectance was reduced to less than 5%. The results revealed that the silicon nanowires length might be readily regulated by varying the etching time. Our result demonstrates that the MACE technique provides a broad range of parameters for producing high-quality vertical silicon nanowires in a simple and controlled way. Light trapping capability is increased at the expense of surface imperfections. The decrease of surface imperfections has been shown to be more beneficial than the reduction of light trapping capability. Silicon nanowire arrays have high prospects for application as an effective radiation trapping material in the revolutionary photovoltaic and other optoelectronic devices due to its very low reflecting surface.