Broadband and Polarization-Insensitive Solar Absorption Enhancement in Thin-Film Organic Solar Cells Using Metallic Nanopillars

It is numerically demonstrated in this paper that integrating 2-D arrays of silver (Ag) nanopillars into organic photovoltaic (PV) cells with thin active layers can enhance absorption efficiency of up to 40% over a broad bandwidth of operation. This corresponds to an increase in integrated AM1.5G absorption at normal incidence from 48% to 67%. Broadband enhancement is observed to be insensitive to the polarization of incident sunlight over a wide angle range. It is attributed to the sunlight strongly coupling to waveguide modes of the active layer and being converted to surface plasmon resonant modes localized around nanopillars.