Charge carrier photogeneration yield in amorphous materials with long-range potential fluctuations

Random intrinsic electrostatic potentials cause local intrinsic electric fields that must affect the Onsager probability of geminate pair dissociation. If the intrinsic fluctuating field is strong enough the dissociation yield could be close to unity even at weak external electric fields and at low temperatures. An analytic model describing the effect of intrinsic field and potential fluctuations on the carrier photogeneration yield is formulated and compared to observed behavior in a-Si:H and a-Se.