Surface-Plasma-Coupled Photovoltaic Cell With Double-Layered Triangular Grating

We present a plasmonic nanostructure design, integrated both of the metallic triangular grating and dielectric antireflection coatings, for ultrathin crystalline silicon solar cells. Considering both polarizations, the current improvement of the optimized structure can reach 76.8% under air mass 1.5 global illuminations. The mode analysis confirms that the enhanced optical absorption is attributed to improved coupling to both guided modes and localized modes. The absorption enhancement of such architecture is a little sensitive to the angle of incidence. The enhancement is still as high as 50% at 60 degrees of incidence.