Modeling of novel heterojunction tunnel structures

Abstract

We have implemented a simple model that allows realistic yet rapid simulation of conventional as well as interband resonant tunneling devices. Using this model we have studied GaAs/AlAs asymmetric triple barrier structures and found that coherence between the quasibound states in the two quantum wells should be observable in the I–V characteristics of the devices. We have also examined InAs–GaSb–InAs broken-gap interband tunnel devices and found that, despite the absence of classically forbidden barrier regions, a resonant tunneling process is involved in producing the observed negative differential resistance. Furthermore, we have found that maximum peak current densities should be found in devices with GaSb layer thicknesses corresponding to a single, rather than a multiple transmission resonance peak in the broken-gap region.