Trap-controlled hopping in doubly doped organic photoreceptor layers

Abstract Hole mobilities have been measured in a polycarbonate binder doped with two kinds of donor molecule simultaneously. The effects of doping concentration, temperature and field were investigated in various compositions with the aim of studying trap-controlled hopping. By double doping we have also gained additional information on the basic transport mechanism. No significant polaronic relaxation was found in any of the transport molecules and our results suggest that energetic disorder has to be invoked to describe hopping phenomena in these systems.