Transient photoconductivity analysis using multiple trapping for rectangular and linear distributions of localized states

Transients related to photoconductivity, photodielectric and photoabsorption changes were simulated for a multiple-trapping model including monomolecular recombination using a linear and a rectangular distribution of localized states. These two distributions provide the same behaviour, which differs from that for the exponential distribution. The nature of the transients depends on the relative time constants in the process and can be categorized into regions of weak, intermediate and strong retrapping. The well known power-law behaviour is obtained only for a limited set of conditions, and it is shown that there is always an exponential tail that has a time constant that is related to the release time of the deepest trap.