TUNNELING PHENOMENA FROM NONEQUILIBRIUM CARRIER DISTRIBUTIONS IN SEMICONDUCTOR HETEROSTRUCTURES

We study tunneling phenomena in semiconductor heterostructures taking into account nonequilibrium carrier distributions. Due to the strong d ependence of tunneling probabilities upon the carrier energy, some of the characteristics of tunneling current depend critically upon the ca rrier distribution function. Thus, to describe these phenomena a corre ct shape of the carrier distribution function is required. We analyze those effects which can be associated with the nonequilibrium characte r of the carrier distribution, both in steady-state resonant tunneling transport and in time-dependent tunneling phenomena. In time-dependen t processes, we analyze the resonant and nonresonant escape time of ex tremely out-of-equilibrium carrier populations excited in a mesoscopic well. We found that these effects may have strong manifestations in r esonant tunneling transport.