Equivalence of multiple-trapping model and time-dependent random walk

A model of multiple trapping from a band of transport states is shown to be equivalent to the continuum limit of the continuous-time-random-walk description of anomalous dispersion developed by Scher and Montroll and the waiting-time distribution function ψ(t) is expressed in terms of the parameters of the multiple-trapping model. Calculations of ψ(t) as a function of temperature are presented for a-Se, using previously determined multiple-trapping parameters obtained from an extensive analysis of transient photocurrent data.