Structural characterization by HRXRD and Raman scattering of AlxGa1_ xSb/GaSb heterostructure

Abstract

- High resolution X-ray diffraction profiles were obtained from Al,Ga 1 .,Sb layers grown on (00 l) GaSb substrates by Liquid Phase Epitaxy (LPE). The out of plane lattice parameter was estimated directly from the asymmetrical diffractions (115) and (-1-15) alloy. These results show that some of the layers are more strained than others. The out of plane lattice parameter as a function of AI content is higher than the corresponding bulk lattice parameter of Al,Ga 1 _,Sb layers obtained with Vegard's law. Two peaks are observed in their Raman spectra over this composition range. The assignment of the observed modes to GaSb-like ts discussed.