Kinetics of light induced defect creation in organic solar cells

The kinetics of light-induced recombination centers in bulk heterojunction organic solar cells are measured as a function of exposure time, intensity, and the illumination photon energy. The density of induced centers increases with exposure but stabilizes partially due to self-annealing. UV exposure is roughly 50 times more effective for defect creation than white light or yellow-filtered white light. Light-induced breaking of C-H bonds to create H-related localized states is proposed as the underlying mechanism.