Charge Recombination in Organic Solar Cells

The recombination of photogenerated charge carriers is the most important loss mechanism in organic solar cells. This chapter first gives an overview of the different recombination channels. The most important loss processes in state-of-the-art devices are then examined in more detail: geminate recombination of charge transfer pairs, as well as non-geminate recombination of free electrons and holes in the bulk and at the contacts. The basic principles will be exemplified with case studies on organic solar cells based on both traditional fullerene and recent non-fullerene acceptors.