Folded acoustic phonons in InAs-AlAs strained-layer superlattices
Raman spectroscopy is used to characterize highly mismatched (7%) InAs‐AlAs superlattices grown by atomic layer molecular beam epitaxy. In particular, folded acoustic modes are presented and compared with two different theoretical models (Rytov and linear chain). We find good agreement between theory and experiments. We estimate, with a simple model, the magnitude of the effect of the strain on the phonon frequency shifts.
Phonons in semiconductor superlattices
Experimental results on phonons in semiconductor super-lattices are almost all from Raman scattering measurements. The superlattice system most studied is GaAs-Ga 1-x Al x As, and in the best-understood geometry the phonons are longitudinal modes with wave vectors perpendicular to the
RAMAN SCATTERING STUDY OF ACOUSTICAL AND OPTICAL FOLDED MODES IN GaAS/GaAlAs SUPERLATTICES
We report the first Raman scattering determination of large parts of the dispersion curves of folded acoustical modes in large period GaAs / GaAlAs superlattices and the first unambiguous observation of a folded optical mode. The analysis of the acoustical dispersion curves gives informations on the lattice dynamics of the alloy. A Kronig-Penney type model of the whole phonon dispersion curves of a superlattice is presented.