Vibrational Eigenmodes And Electron-Phonon Interaction In Quantum Dot-Quantum Well Structures

In this paper, we have studied the vibrational eigenmodes and the electron-phonon interaction in a quantum dot-quantum well (QD-QW) structure which is formed by a quantum dot composed of a non-polar semiconductor coating with a polar semiconductor spherical slab, embedded in another non-polar surrounding medium. Firstly, the bulk longitudinal optical (LO) modes and the interface optical (IO) modes in the QD-QW structures are investigated within the framework of continue medium. The eigen-frequencies of the IO modes are derived and numerical calculations are performed for a ZnSe (slab) QD-QW structure with different well width. It is found that: the eigen-frequencies of IO modes depend on not only the angular quantum numbers l but also the well width. There are two branch IO modes for given l . With the well width increasing, theeigen-frequencies of one mode increases and the other one decreases. Then, the quantization ofpolarization potential has been obtained by quantizing the vibrational eigenmodes, after that the electron-IO phonon and the electron-LO phonon interaction Hamiltonian have been derived, respectively.