Interface optical phonons and their electron-phonon interactions in ZnS/CdS multi-shell spherical quantum dots

The properties of interface optical phonons and their electron-phonon interactions in ZnS/CdS multi-shell spherical quantum dots are studied by adopting dielectric continuum model. The dispersion curves and electron-phonon coupling strengths for interface optical phonons in ZnS/CdS multi-shell dots are calculated and analyzed in detail. It is shown that the number of interface optical phonon branches increase with the increase of layers of multi-shell quantum dots. The number of interface optical phonons increase two branches for increasing one layer material. The dispersions of interface optical phonon with low quantum number l are weak. The electron-interface optical phonon interactions are mainly localized at hetero-interfaces. The interface optical phonons with low quantum number l have important contribution to electron-interface optical phonon interactions.