The Study of Optical and Electrical Properties of Short-Pitch Plasmonic Solar Cells

Metallic gratings have drawn great attention over the past few years due to effective light trapping and power conversion efficiency enhancement in organic solar cells (OSCs). Novel OSCs incorporated short-pitch metallic grating into the conventional OSCs as the back electrode is presented. The optical and electrical properties of OSCs are investigated by applying the finite-difference frequency-domain method. It is found that the light absorption at 400-650 nm in the active layer is strongly improved, compared with the standard structure without metallic grating. The underlying physical mechanism is due to the surface plasmon resonance and the interaction between two neighbor gratings, which undoubtedly enhances the electrical properties such as short-circuit current (J_SC), fill factor, and power conversion efficiency. Meanwhile, the optical and electrical properties of OSCs with different groove widths are also investigated. With an optimal groove width of 4 nm, the overall performance of OSCs is enhanced. This paper indicates that OSCs incorporated short-pitch metallic grating are promising candidates for high-performance OSCs.