Forbidden one-LO-phonon resonant Raman scattering and multiphonon scattering in pure CdTe crystals

Abstract

We have performed experiments to show the resonant enhancement of the forbidden first-order LO mode at the ${\mathit{E}}_{0}$+${\mathrm{\ensuremath{\Delta}}}_{0}$ gap of pure CdTe at 17 K. We explain this forbidden scattering in terms of intrinsic intraband Fr\"ohlich interaction. In our experiments we also observe multiple-LO-phonon scattering up to four orders under both incoming and outgoing resonant conditions. The multiphonon spectra are briefly discussed and compared with other cadmium chalcogenides.