CHARACTERIZATION OF HETEROINTERFACES AND SURFACES IN INSB ON GAAS ANDIN INAS ALSB QUANTUM-WELLS/

Resonant Raman scattering by longitudinal optical (LO) phonons and by interface modes was used to study InSb/GaAs and InAs/AlSb heterointerf aces for InSb on GaAs and for InAs/AlSb quantum wells respectively, gr own by molecular beam epitaxy. Raman spectra recorded from samples wit h InSb layers ranging in thickness from 10 to 300 monolayers indicate that, to achieve two-dimensional growth of InSb on GaAs with good crys talline quality, the layer thickness must exceed around 100 monolayers . From the dependence on excitation power of electric-field-induced LO phonon scattering measured for a series of n- and p-type doped thick InSb layers, it is concluded that the surface Fermi level is pinned at the valence band edge. Ln InAs/AlSb quantum wells, scattering by an I nSb-like interface mode is observed which resonates at approximately t he InAs E(1) energy gap.