RAMAN LIGHT-SCATTERING DUE TO COLLISIONS OF WANNIER-MOTT EXCITONS WITH IMPURITIES AND BETWEEN THEM

The theory of Raman light scattering due to Coulomb (exchange) interac tion of an exciton in an intermediate state with neutral impurities in semiconductors is developed. The consideration is based on the third- order perturbation theory. The possibility of such an approach is prov ed even for conditions of resonant Raman light scattering in direct-ga p semiconductors. The theoretical estimations for scattering cross-sec tion and scattering efficiency are well fitted with experimental data obtained by Ulbrich et al. on CdTe crystals. However, full explanation of these data must involve exciton scattering on bound excitons or bi excitons.