Study on light scattering by longitudinal-acoustic phonons in GexSi1-x/Si superlattices

Using photoelastic mechanisms and taking into account the differences between the acoustic and photoelastic parameters of the two constituents in the SLs, we have studied the Raman scattering intensities of the folded longitudinal acoustic (FLA) phonons in GexSi1−xSi superlattices (SLs). The relative intensities calculated for the FLA phonons are in good agreement with the experimental results at frequencies up to about 50 cm−1. The strong acoustic attenuation in Ge0.5Si0.5Si SLs, reported previously, has not been observed in this work.