Evaluation of interfaces in narrow InAs/AlSb quantum wells

Abstract

InAs/AlSb quantum wells may be grown with two types of interfaces: InSb-like and AlAs-like. The interface type refers to the half-monolayer of the well material and half monolayer of barrier which are in contact. The type and quality of the quantum well interface is critical to the ISBT intensity and lineshape and, to a lesser extent, position. In addition to FTIR spectroscopy of the ISBT, we have performed transmission electron microscopy (TEM) to directly evaluate the quality of the interfaces at the atomic level. In order to evaluate the effects of interface type and quality on ISBT intensity, lineshape, and linewidth, we studied the TEM of a 10 nm QW sample with InSb-InSb interfaces and a 3 nm QW sample with InSb-AlAs interfaces.