Temperature-independent quantum yield of carrier photogeneration in weakly disordered conjugated polymers

A model of field-assisted intrasegmental dissociation of optical excitations in weakly disordered conjugated polymers is formulated. The model accounts for both over-barrier separation of charge carriers and tunneling 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 photogeneration which show a strong field dependence but, remarkably, virtually no temperature dependence.