Analysis and optimization of surface plasmon-enhanced organic solar cells with a metallic crossed grating electrode.

We perform a systematic analysis of enhanced short-circuit current density (J(sc) in organic solar cells (OSCs) where one metallic electrode is optically thick and the other consists of a two-dimensional metallic crossed grating. By examining a model device representative of such surface plasmon (SP)-enhanced OSCs by the Fourier modal and finite-element methods for electromagnetic and exciton diffusion calculations, respectively, we provide general guidelines to maximize J(sc) of the SP-enhanced OSCs. Based on this study, we optimize the performance of a small-molecule OSC employing a copper phthalocyanine-fullerene donor-acceptor pair, demonstrating that the optimized SP-enhanced device has J(sc) that is 75 % larger than that of the optimized device with an ITO-based conventional structure.