CALCULATION OF INCOHERENT TUNNELING AND VALLEY CURRENT IN RESONANT TUNNELING STRUCTURES

We have calculated the contribution of intrinsic scattering processes (LO phonons, acoustic phonons, alloy disorder) to electron tunneling through a resonant tunneling structure. In GaAs/GaAlAs our results indicate that a major part of the valley currently observed in the best samples is already accounted for by these processes. We discuss the effect of the thickness of the barriers on the peak to valley ratio at room temperature, both in GaAs/GaAlAs and in GaInAs/AlInAs, which has shown much lower valley currents. For resonant tunneling through the second level of the well, our calculations show that a major part of the current is due to intersubband scattering inside the well, so that the transport is truly sequential in that case. © 1990.