Influence of phonons on the electronic energy spectrum of small semiconductor quantum dots in a dielectric matrix

A diagrammatic technique developed for Green’s functions with inclusion of multiphonon processes is used to investigate the electronic energy levels and the phonon replicas corresponding to them in a semiconductor quantum dot (QD) embedded in a dielectric matrix. It is shown, with reference to GaAs, CdSe, and CuCl quantum dots embedded in glass, that in the case of QD potential wells of a finite depth the shifts of the electronic energy levels decrease with decreasing QD size, irrespective of the strength of electron-phonon coupling in the nanoheterostructure. Theoretically calculated positions of the phonon replicas for CdSe in glass agree with the experimental data on Raman scattering.