Vm. Fomin et al., MULTIPHONON PHOTOLUMINESCENCE AND RAMAN-SCATTERING IN SEMICONDUCTOR QUANTUM DOTS, Solid-state electronics, 42(7-8), 1998, pp. 1309-1314
Multiphonon optical spectra of semiconductor quantum dots, in particul
ar, of nanocrystals with structure imperfections, are studied in the f
ramework of a non-adiabatic approach. The phonon modes and the amplitu
des of the electron-phonon interaction are found taking into account b
oth electrostatic and mechanical boundary conditions, as well as the f
inite number of vibrational degrees of freedom in quantum dots. Select
ion rules for Raman scattering are deduced for quantum dots of semicon
ductor materials with a degenerate valence band. The effects of non-ad
iabaticity of the exciton-phonon system are shown to lead to a signifi
cant enhancement of phonon-assisted transition probabilities and to a
substantial difference of the optical spectra from the Franck-Condon p
rogression. Calculated optical spectra compare well with experimental
data on photoluminescence and Raman scattering in CdSe and PbS quantum
dots. (C) 1998 Elsevier Science Ltd. All rights reserved.