Lithography-free wide-angle antireflective self-cleaning silicon nanocones.

Low-cost, wideband, and wide-angle antireflective layers are of prime importance to photovoltaic and other optoelectronic applications. We report a novel fabrication methodology of random textured silicon nanocones (SiNCs) array through metal-assisted chemical etching combined with oxidation. The optical properties of the fabricated structure are studied theoretically and experimentally. The random textured SiNCs array showed very promising broadband antireflective properties through the entire visible wavelength range at different incident angles up to ±60°. In addition, the nanostructures inherently could become self-cleaning due to the high contact angle. This random cheap textured SiNCs array increases the absorption efficiency of photodetectors and reduces its cost.