Fabrication of GaAs subwavelength structure (SWS) for solar cell applications

We developed a novel GaAs subwavelength structure (SWS) as an antireflective layer for solar cell applications. The GaAs SWS patterns were fabricated by a combination of nanosphere lithography (NSL) and reactive ion etching (RIE). The shape and height of the GaAs SWS were controlled by the diameter of the SiO2 nanospheres and the etching time. Various GaAs SWS were characterized by the reflectance spectra. The average reflectance of the polished GaAs substrate from 200nm to 800nm was 35.1%. However, the average reflectance of the tapered GaAs SWS was reduced to 0.6% due to scattering and moth-eye effects.