Interface/surface optical phonon in onion-like quantum dots

We calculate the interface/surface phonon in onion-like quantum dots by using dielectric continuum approach. The form of the phonon potential of the onion-like quantum dots and the electron–phonon interaction Hamiltonian are obtained. Core/shell quantum dots and quantum dot quantum well are studied in detail. The interface/surface phonon modes and corresponding frequencies as a function of the sizes of the structure are investigated. We observe that the asymptotic behavior is depended on the host medium. The sensitivity of the interface/surface phonon frequencies are decreasing with the increasing of the shell thickness. The contribution of different angular momentum quantum numbers to the electron–phonon interaction are given for the onion-like quantum dots. Numerical calculations are performed on the CdS/ZnS and CdS/ZnS/CdS heterostructure which is embedded in the polyethylene.

► We construct the interface phonon potential for onion like quantum dots. ► On what extent the phonon frequency depend on shell thickness are examined. ► Thicker shell decrease electron–phonon interaction for certain phonon modes. ► Phonon modes with larger angular momentum number contribute less to the interaction.