Strain-fluctuation effect on Raman spectra

We show that the interaction of phonons with static strain fluctuations induces an inhomogeneous shift and a broadening of Raman spectra. The Raman scattering cross section is calculated in terms of the averaged strain, which relaxes smoothly in real space, and of the strain correlation function. Two regimes of short- and long-range disorder with different line shapes are found. The agreement with experiment data collected on the 3C-SiC/Si interface is satisfactory.