Interference effects of Raman scattering by Lo-phonons near the E_o+Δ_o-GAP studied on (113), (111), and (111) faces of GaAs

We have studied the interference of dipole-allowed deformation-potential Raman scattering and dipole-forbidden Fröhlich-induced scattering by LO-phonons near the Eo+Δo-gap on the (113) face of MBE-GaAs and on the (111) and (111) faces of bulk GaAs at 100 K. Absolute values of the squared Raman tensor are displayed. A fit of the resonance profile reveals that the purity of the MBE-sample under investigation compares well with that of (001) LPE-samples studied previously. The (111) and (111) faces of GaAs show opposite signs in the interference, in accordance with symmetry considerations. © 1987.