Effect of pressure on the first-order Raman intensity in semiconductors

One-phonon Raman scattering in the zinc-blende-type semiconductors under hydrostatic pressure and with excitation energies below the fundamental gap is examined. A microscopic description of the scattering intensities and Raman cross sections for longitudinal and transverse optical phonons is presented in terms of deformation potential and interband allowed Fr\"ohlich interaction. Calculations are compared to the experimental results for $\mathrm{ZnTe}$, i.e., the variation of the integrated Raman intensity with pressure for $\mathrm{LO}(\ensuremath{\Gamma})$ and $\mathrm{TO}(\ensuremath{\Gamma})$ modes. So as to make possible a comparison with experimental data, the pressure dependence of all parameters entering into the description of the scattering processes had to be taken into account. In particular, the pressure variation of the relevant conduction band states and optical deformation potential were evaluated using the pseudopotential plane-wave method within the local density approximation to the density functional theory. The present theoretical approach can be used to evaluate the Raman scattering intensities and cross sections in other II-VI and III-V compounds under pressure.