Optical properties of stepped-cone silicon nanostructures fabricated by nanosphere mask and RIE method

Highly ordered silicon nanostructures were fabricated using the nanosphere mask and reactive ion etching method. A self-assembled SiO2 nanospheres monolayer obtained by spin-coating method was used as an etching mask for pattern transfer onto the Si substrate. The shape and height of these nanostructures were precisely controlled by the etching time. The optical properties of as-prepared nanostructure were investigated by experiments and simulation. Experimental results showed that the average reflectance in wavelength range of 400-1000 nm decreased from 33.6% to 4.6%. Simulation results were in good agreement with experimental results. Accordingly, this novel method is therefore considered to be an easy approach to fabricate different nanostructures for broadband antireflective surfaces for solar cells.