LAUSR

Abstract A broadband-absorption enhancement in two kinds of polymer-based organic solar cells (OSCs) is demonstrated in this work by employing micro-nano composite gratings (MNCGs). The structure of MNCGs is nano-grating covering on the surface of micro-grating. By embedding the MNCGs at the interface of the active layer/Ag cathode, the multi-absorption-enhancement mechanisms, such as dual-microcavity resonance, plasmon-cavity polaritons and light-scattering effects, are excited and result in a broadband-absorption enhancement. The light absorption of active layer in the MNCG-based OSC is numerically calculated. As a result, comparing to the planar OSCs, the absorption intensity is increased by 50.41% and 20.43% in these two kinds of polymer-based OSCs, respectively. Meanwhile, the MNCGs can also be universally used in all kinds of polymer-based OSCs to increase the light absorption of the active layer.