The electronic properties of [001] (AlAs)(n)-(AlSb)(n) short-period st
rained-layer-superlattices (SPSLS) lattice matched to InP, for n less
than or equal to 4, have been calculated with a first-principles self-
consistent pseudopotential method. The layer dependence of the interpl
anar relaxations, direct and indirect band gaps, and spin-orbit and va
lence band strain splittings are studied. Evolution of the superlattic
e states from the bulk constituents is discussed in terms of wavefunct
ion mixing and band repulsion due to zone-folding. The band structures
of the SPSLSs are compared with a disordered alloy of AlAs0.5Sb0.5 re
presented by the special quasirandom structure. We fmd that continuum
models of the total valence band splitting (strain and spin-orbit) do
not accurately represent the electronic structure of lattice mismatche
d SPSLS, due to strong mixing of the heavy-and light-hole states acros
s the interface. (C) 1998 Academic Press Limited.