Temperature dependence of the band overlap in InAs/GaSb structures

Publisher Website
Google Scholar
Abstract
We have studied the temperature dependence of the band overlap in InAs/GaSb structures by performing magnetotransport measurements on both semiconducting and semimetallic superlattices at temperatures between 110 and 340 K and in fields up to 45 T. Semiconducting samples have very few carriers at 4 K, but at these higher temperatures intrinsic carriers are thermally excited across the energy gap. By measuring the variation of the electron and hole densities with temperature it is possible to determine the energy gap between the electron and hole confinement energies and thus the band overlap between the InAs conduction band and the GaSb valence band. We find that this overlap is 30 meV larger at 300 K than at 4 K, which agrees with similar measurements on a semimetallic sample and also the model-solid theory of Van de Walle.