Folding of acoustic-phonon modes in GaAs/AlAs (311)A superlattices in the direction perpendicular to nanofacets

摘要

GaAs/AlAs superlattices grown on a nanofaceted (311)A surface are studied by atomic-force microscopy and Raman scattering spectroscopy. The spectra of backscattered light in the direction perpendicular to the nano-facets exhibit peaks corresponding to folded acoustic phonons. The period estimated from the positions of these peaks is 1. 6 nm, which corresponds to half of the spacing between the nanofacets.