Orientation‐dependent resonant raman scattering in InSb and GaSb at the E 1 –E 1 +Δ 1 region

The resonance of the first order Raman scattering by LO and TO phonons near the E 1 and E 1 + Δ 1 electronic gaps of InSb and GaSb is presented. Whereas for forbidden LO scattering the spectra are independent of the orientation of the crystal surface, for allowed TO and LO scattering the resonance spectra depend strongly on the surface orientation. This orientation dependence is discussed in terms of both allowed and first order vector induced ( q ‐dependence, electric field, etc.) scattering processes.