Recombination Kinetics in Organic-Inorganic Perovskites: Excitons, Free Charge, and Subgap States

It has been proposed that organic-inorganic perovskites may provide the ``disruptive'' technology needed to deliver widespread and affordable solar power. To reach this goal, a detailed understanding of their material properties and behavior in working devices is needed. The authors present a robust model that explains charge recombination in the presence of subgap trap states in these materials. This study provides concrete predictions regarding the most important material parameters for improved solar-cell performance of these perovskites.