Abstract
Resonant Raman scattering by longitudinal optical (LO) phonons as well as by interface modes has been used to investigate the heteroepitaxial growth of GaSb and InSb on GaAs, which are combinations of materials exhibiting a large lattice mismatch, and to study the heterointerfaces in nearly lattice matched InAs/ (AlGa)Sb quantum wells and superlattices. Resonant LO phonon scattering is found to provide detailed insight in the initial stage of heteroepitaxial growth revealing a significant intermixing of the group V atoms at the GaAs/GaSb interface. For GaSb-capped InAs/AlSb quantum well structures tuning the incident photon energy into resonance with an appropriate band gap energy of one of the constituents allows the vibrational modes of that individual layer to be probed selectively, in spite of the almost coincident InAs and GaSb LO phonon frequencies. Similarly, in InAs/GaSb superlattices scattering by the InSb-like or GaAs-like interface modes, depending on whether the structure was grown with either In-Sb or Ga-As interface bonds, can be enhanced by excitation close to resonance with the E1 band gap energy of either of the two constituents.