WELL WIDTH DEPENDENCE OF ELECTRON-TRANSPORT IN MOLECULAR-BEAM EPITAXIALLY GROWN INAS/ALSB QUANTUM-WELLS

We present the results of a systematic study of the low-field electron transport as a function of the well width for InAs/AlSb quantum wells grown on nominally [100]-oriented, GaAs semi-insulating substrates. Both room-temperature and low-temperature mobilities are significantly reduced in narrow wells due to the dominance of interface roughness scattering. The mobility peaks for well widths around 125 angstrom, and then decays again, most probably due to the onset of scattering by misfit dislocations nucleated as the quantum well width exceeds the critical layer thickness imposed by the 1.3% lattice mismatch between InAs and AlSb.