Enhanced efficiency of Cu(In,Ga)Se2 solar cells with antireflection coating layers of MgF2 and ZnO nanorods

Double antireflection layers consisting of MgF2 and ZnO nanorods layers were grown on a gallium doped MgZnO transparent conducting oxide layer to enhance the efficiency of the Cu(In,Ga)Se2 (CIGS) solar cells. When ZnO nanorods were coated with the MgF2 layer, the weighted global reflectance was decreased to 5.5% and the enhanced solar power conversion of CIGS solar cells was 17%. The enhancement of the solar cell performance was attributed to the reduction in Fresnel reflection by the gradually changed refractive index of the double antireflection coating layers.