MULTIQUANTUM OPTICAL PROCESSES IN SEMICONDUCTOR QUANTUM DOTS

Manifestations of non-adiabatic multiphonon transitions in optical pro perties of semiconductor quantum dots are theoretically analyzed accou nting for the influence of the spherical confinement on the phonon ene rgy spectrum. The role of phonon branches of different symmetry in the spectra of Raman scattering is ascertained. The effects of non-adiaba ticity of the exciton-phonon system are shown to significantly enhance phonon-assisted transition probabilities and to lead to multiphonon o ptical spectra which are considerably different from the Franck-Condon progression. Calculated spectral progressions compare well with exper imental data on photoluminescence and Raman scattering in CdSe and CdS exS1-x quantum dots.