PHONON-ASSISTED OPTICAL-TRANSITIONS IN SPHERICAL NANOCRYSTALS

In order to interpret the photoluminescence spectra of spherical nanoc rystals with zincblende structure, the intensities of phonon satellite s are analyzed taking into account both the internal non-adiabaticity of the exciton-phonon system (the proper Jahn-Teller effect) and the e xternal non-adiabaticity (the pseudo-Jahn-Teller effect). The effects of nonadiabaticity are shown to lead to a significant enhancement of p honon-assisted transition probabilities and to a more complicated depe ndence of these probabilities on the number of emitted or absorbed pho nons in comparison with the results of adiabatic theory. The calculate d relative intensities of the phonon satellites compare well with the experimental data on the photoluminescence of the CdSe spherical nanoc rystals. (C) 1997 Elsevier Science Ltd.