The second-order Raman spectrum of AlAs has been measured on samples grown by molecular-beam epitaxy (MBE). The results show significant discrepancies with model calculations of the phonon density of states, but are consistent with recent first-principles calculations. This first-principles approach has been used to compute the phonon energies in GaAs-AlAs superlattices, with controversial implications regarding the sharpness of MBE-grown interfaces. The Raman results presented here support the conclusions of the first-principles analysis.
ASJC Scopus subject areas
- Condensed Matter Physics