Kinetics of light induced defect creation in organic solar cells

Abstract

The kinetics of light-induced recombination centers are measured in bulk heterojunction organic solar cells, as a function of exposure time, intensity and the illumination photon energy. The density of recombination centers increases with exposure time but stabilizes due to self-annealing. UV exposure is roughly ten times as effective for defect creation as white light or yellow-filtered white light for the same exposure intensity. The recombination centers that are created by light are indistinguishable from those created by x-ray irradiation for which the evidence indicates that the breaking of C-H bonds to create H-related localized states is the underlying mechanism.