INFLUENCE OF GROWTH DIRECTION AND STRAIN CONDITIONS ON THE BAND LINEUP AT GASB INSB AND INAS/INSB INTERFACES/

First-principles full-potential linearized augmented plane wave calcul ations have been performed for lattice mismatched common-atom LII-V in terfaces. In particular, we have examined the effects of epitaxial str ain and ordering direction on the valence-band offset in [001] and [11 1] GaSb/InSb and InAs/InSb superlattices, and found that the valence-b and maximum is always higher at the InSb side of the heterojunction, e xcept for the common-anion system grown on an InSb substrate. The comp arison between equivalent structures having the same substrate lattice constant, but different growth axis, shows that for comparable strain conditions, the ordering direction slightly influences the band lineu p, due to small differences of the charge readjustment at the [001] an d [111] interfaces. On the other hand, strain is shown to strongly aff ect the valence-band offset; in particular, as the pseudomorphic growt h conditions are varied, the bulk contribution to the band lineup chan ges markedly, whereas the interface term is almost constant. On the wh ole, our calculations yield a band lineup that decreases linearly as t he substrate lattice constant is increased, showing its high tunabilit y as a function of different pseudomorphic growth conditions. Finally, the band lineup at the lattice matched InAs/GaSb interface determined using the transitivity rule gave perfect agreement between predicted and experimental results.