COMPARISON BETWEEN MULTIPLE-TRAPPING AND MULTIPLE HOPPING TRANSPORT IN A RANDOM MEDIUM

Motion of excess charge carriers in a random medium via either multipl e trapping (MT) or multiple hopping (MH) has been studied both analyti cally and via simulation for exponential as well as Gaussian density o f states. Waiting-time distribution as well as transient current calcu lated under the premise of MT transport agree with the equivalent quan tities obtained for the MH case via simulation. This indicates that at low fields the experimental signatures of both transport mechanisms a re indistinguishable despite differences concerning the underlying ele mentary processes. The likely reason is the existence of a transport e nergy in either case. The waiting time distribution for a Gaussian den sity of states deviates from an algebraic law.