Raman scattering from confined acoustic phonons of silicon nanocrystals in silicon oxide matrix

In this work, silicon-rich silicon oxide films of different stoichiometry were annealed at high temperatures in order to obtain silicon nanocrystals embedded in silica. The low-frequency Raman scattering has been observed and related to acoustic phonons confined in these nanocrystals. It has been found that this scattering consists of two modes: one at a lower frequency and one at a higher frequency. The depolarization ratios for these modes …