TEMPERATURE-INDEPENDENT QUANTUM YIELD OF CARRIER PHOTOGENERATION IN WEAKLY DISORDERED CONJUGATED POLYMERS

A model of field-assisted intrasegmental dissociation of optical excit ations in weakly disordered conjugated polymers is formulated. The mod el accounts for both over-barrier separation of charge carriers and tu nneling dissociation of excitations in the course of their relaxation from an initial higher excited state to the lowest excited state. The model offers an explanation of recent observations of charge carrier p hotogeneration which show a strong field dependence but, remarkably, v irtually no temperature dependence. (C) 1998 Elsevier Science B.V. All rights reserved.