Theoretical model of stress-induced triply resonant Raman scattering

A theoretical model of stress-induced triply resonant second-order Raman scattering in zinc-blende-type semiconductors including excitonic effects has been developed. We consider one deformation potential and one Fröhlich interaction for the electron one-phonon coupling. An analysis is made of the discrete and continuous spectra of the exciton virtual states contribution to the Raman tensor. Calculated curves of the Raman scattering efficiency as a function of incident photon energy for constant stress and vice versa are presented. These curves are in good agreement with the experimental resonance profiles of the two-LO-phonon and TO- plus LO-phonon peaks in GaAs. From the fit, the values and the behavior of the lifetime broadenings of the heavy- and light-hole excitons with stress are obtained.