Characterization of antireflection moth-eye film on crystalline silicon photovoltaic module.

We have characterized antireflection (AR) moth-eye films placed on top of crystalline silicon photovoltaic (PV) modules by indoor and outdoor experiments and examined improvements in conversion efficiency. The effects of the ratio of diffuse solar irradiation to total solar irradiation (diffusion index) and incident angle on efficiency have been quantitatively analyzed. Using computer simulations, yearly efficiency improvements under different installation conditions have been projected. We have shown that the use of AR moth-eye films offers the best advantages. Further, vertical tilt angle installation leads to the highest efficiency improvement, whereas spectral matching with the PV modules influences the efficiency improvement.