Effect of interface composition and growth order on the mixed anion InAs/GaSb valence band offset

Abstract

We have used x-ray photoelectron spectroscopy (XPS) to measure the dependence of the InAs/GaSb valence band offset on both interface composition and growth order. Molecular beam epitaxy was used to grow InAs-on-GaSb and GaSb-on-InAs interfaces with both InSb-like and GaAs-like interface compositions. Analysis of XPS core level separations showed no dependence of the valence band offset on interface composition; however, a 90 meV increase in the valence band offset was observed for InAs grown on GaSb compared to GaSb grown on InAs. This difference is attributed to the extended nature of the InAs-on-GaSb interface. Results from analysis of an intentionally extended GaSb-on-InAs interface were consistent with this conclusion. © 1995 American Institute of Physics.