Molecular Beam Epitaxy of Low-Strained CdSe/CdMgSe Heterostructures on InAs(001) Substrates

Abstract

CdSe/CdMgSe quantum well heterostructures have been grown on InAs(001) substrates by molecular beam epitaxy. Their optical and structural properties are studied by photoluminescence, transmission electron microscopy (TEM), electron probe microanalysis and X-ray diffraction. A comparative analysis of two types of heterovalent III–V/II–VI interfaces (InAs/CdSe and InAs/ZnTe) and their effect on the structural properties of CdMgSe layers are discussed. Structures with the InAs/ZnTe interface exhibit a much lower stacking fault density (below the TEM detection limit of 106 cm—2) as compared to those with the InAs/CdSe interface, which is explained by the high probability of In2Se3 nucleation at the latter interface. The CdMgSe energy gap versus composition dependence as well as the optical bowing parameter and the zinc-blende MgSe band-gap energy are determined.