The dispersive photoconductivity decay following a short-pulse excitation in phosphorus-doped and undoped hydrogenated amorphous silicon prepared by RF glow discharge decomposition of silane has been investigated.
It is found that the dispersion parameter is temperature dependent as expected for extended-state transport controlled by multiple trapping. The dispersion parameter is nearly linear to the applied field.
The recombination lifetime in undoped a-Si:H is also determined from the transient photoconductivity decay and found to be on the order of $10^{-6} sec$.
The density of localized states is obtained for a small energy range corresponding to the time scale of the observation.
The activation energy obtained from the transient photoconductivity decay is proportional to ln(t) and the result is compared with the Tiedje model.
