Drift-Diffusion Studies of Compositional Morphology in Bulk Heterojunctions: The Role of the Mixed Phase in Photovoltaic Performance

Abstract

Organic solar cells are typically fabricated from a blend of electron-donating and -accepting materials. When mixed, these materials may separate into pure components, but in some cases there may be an intermediate phase of mixed composition at the interface. Using drift-diffusion modeling, the authors reveal that there is an optimal, moderate amount of mixed-phase interfacial region for best photovoltaic device performance, depending on the sizes and morphologies of the pure-phase regions.