Bottom-up grown ZnO nanorods for an antireflective moth-eye structure on CuInGaSe2 solar cells

A bottom-up technique using an aqueous solution method was adopted to fabricate a bio-mimicked antireflection (AR) coating for a CuInGaSe2 (CIGS) solar cell. On controlling the morphology of the solution-grown zinc oxide (ZnO) nanostructure the average reflectance of the CIGS solar cell employing the bio-mimicked AR coating decreased from 6.14% to 1.46%, and the efficiency of the solar cell increased from 10% to 11.5%. The mechanism by which the solar cell′s efficiency was enhanced is thought to be the effect of the gradual increase in the refractive index between air and the top electrode due to the insertion of the ZnO nanostructure.