Interface optical phonons in spherical quantum-dot/quantum-well heterostructures

Interface optical phonons are studied in the case of a spherical quantum-dot/quantum-well (QD/QW) heterostructure by applying a dielectric continuum approach. The prototypical case is a QD/QW of CdS/HgS in the form of spherical shell of HgS embedded on a spherical CdS QD, a kind of structure intensively investigated in the latter times. We also assume the QD/QW hetrerostructure surrounded by a host material which is modeled in the form of an infinite dielectric medium which does not participate of the polar optical vibrations. The possible interface phonon modes (CdS-and HgS-SO phonons), the corresponding frequencies and the electron-phonon interaction Hamiltonian are reported. A detailed discussion is made of the SO phonons fundamental characteristics and of the strength of the electron-phonon interaction.