Ag Nanowire @ Nano-groove Fabrication for Enhanced Light Harvesting Through Silicon Chemical Etching

Chemical etching was employed to fabricate Ag nanowire @ nano-grooves on silicon to increase light harvesting. Ag nanowire @ nano-groove structures (300 nm to 1.7 μm in size) were obtained by controlling the etching time. A significant increase in the surface roughness was achieved around the Ag nanowire @ grooves with an etching time of 10–30 min. According to finite difference time domain simulations, a significant increase in both the light intensity and light path length were observed with the Ag nanowire @ nano-groove nano-structures on the silicon substrate. Increasing the opening sizes of the grooves to ~ 255 nm and the roughness of the Ag nanowire and groove surface to ~ 30 nm further enhanced the light harvesting abilities. This work not only provides a deeper insight into metal assisted silicon etching, but also indicates a possible way to enhance the light harvesting abilities of thin film solar cells.