OPTICAL AND STRUCTURAL INVESTIGATIONS OF INTERMIXING REACTIONS AT THEINTERFACES OF INAS ALSB AND INAS/GASB QUANTUM-WELLS GROWN BY MOLECULAR-BEAM EPITAXY/

Several issues related to the interface structure in molecular-beam ep itaxially grown InAs/AlSb and InAs/GaSb heterostructures are investiga ted by Raman scattering, photoluminescence and X-ray measurements. The measurements reveal differing degrees of layer intermixing at the int erfaces (IFs), greatest for AlAs-like IFs in the InAs/AlSb material sy stem, less pronounced for GaAs-like IFs in the InAs/GaSb material syst em, and smallest for InSb like IFs in both systems. This intermixing i s both thermodynamically favoured and, in addition, driven by a loweri ng of the strain-induced component of the surface energy.