Nanopatterned front contact for broadband absorption in ultra-thin amorphous silicon solar cells

Broadband light trapping is numerically demonstrated in ultra-thin solar cells composed of a flat amorphous silicon absorber layer deposited on a silver mirror. A one-dimensional silver array is used to enhance light absorption in the visible spectral range with low polarization and angle dependencies. In addition, the metallic nanowires play the role of transparent electrodes. We predict a short-circuit current density of 14.6 mA/cm2 for a solar cell with a 90 nm-thick amorphous silicon absorber layer.