RESONANT RAMAN-SCATTERING BY LONGITUDINAL-OPTICAL PHONONS IN ZN1-XMNXSE (X = 0, 0.03, 0.1) NEAR THE E0 GAP

The efficiency of resonant one- and two-LO-phonon Raman scattering in oriented cubic Zn1-xMnxSe single crystals with x=0,0.03,0.1 is studied for incident photon energies near the E0 fundamental band gap. Absolute values of the Raman scattering efficiency (RSE) are determined for several backscattering configurations by using a sample substitution method and by correcting the measured intensities with respect to absorption, reflection, and refraction. The experimental data for one-LO-phonon scattering via deformation-potential and Fröhlich electron-phonon interaction are quantitatively compared with model calculations for the absolute RSE, where bound and continuum exciton states are considered as intermediate electronic states. Near resonance, strong LO-phonon intensities are measured in backscattering configurations where scattering via the deformation-potential and Fröhlich interaction is forbidden according to the standard Raman selection rules. © 1990 The American Physical Society.