Enhanced Omnidirectional Optical Absorption in a Nanopatterned Silicon Thin Film for Photovoltaic Applications

We show that the optical absorption in thin-film photovoltaic cells can be enhanced by texturing the silicon absorbing layer into nanostructured array. The optical absorption of the proposed configuration is enhanced by 70% compared to a nonpatterned silicon thin film of the same thickness. Furthermore, the proposed silicon thin film PV cell has a good angle-independent response of up to 60°. The omnidirectional absorbance enhancement of the nanopatterned silicon thin film is attributed to its unusual light trapping mechanism and omnidirectional bandgap.