Comparison between multiple trapping and multiple hopping transport in a random medium

Abstract

Motion of excess charge carriers in a random medium via either multiple trapping (MT) or multiple hopping (MH) has been studied both analytically and via simulation for exponential as well as Gaussian density of states. Waiting-time distribution as well as transient current calculated under the premise of MT transport agree with the equivalent quantities obtained for the MH case via simulation. This indicates that at low fields the experimental signatures of both transport mechanisms are indistinguishable despite differences concerning the underlying elementary processes. The likely reason is the existence of a transport energy in either case. The waiting time distribution for a Gaussian density of states deviates from an algebraic law. \textcopyright{} 1996 The American Physical Society.