Theoretical analysis of resonant Raman scattering by 2LO phonons

A detailed theoretical treatment of the second-order Raman efficiency is given for incident photon energies below an excitonic resonance. The Wannier excitons are considered as intermediate states in the scattering process. By using the Green's function method, the expression for the Raman efficiency is obtained. The contributions of the two sequences of the intermediate states, s-s-s and s-p-s, are analyzed. The second-order Raman efficiency is calculated for CdS. Copyright (C) 2001 John Wiley & Sons, Ltd.