Optical vibration modes in spherical core-shell quantum dots

摘要

Using a dielectric continuum approach, the optical vibration modes in a spherical core-shell quantum dots (QDs) imbedded in a host nonpolar material are studied. The dispersion relation and the corresponding electron-phonon interaction Hamiltonian are derived. The numerical calculations for the CdSe/ZnS system are performed. The results reveal that there are three branches frequencies of interface/surface optical phonon in the system. A detailed discussion of the combined effects of the spatial confinement and dielectric mismatch between the dot and the host medium is given.