Electron-phonon interaction in quantum-dot/quantum-well semiconductor heterostructures

TL;DR

This paper investigates polar optical phonons in quantum-dot/quantum-well heterostructures using the dielectric continuum approach, deriving the electron-phonon interaction Hamiltonian and analyzing polaronic effects on electronic energy levels.

Contribution

It provides a detailed model of electron-phonon interactions in QD/QW heterostructures, including polaronic corrections and their dependence on structure size.

Findings

Polaronic corrections vary with quantum dot and well sizes.

The strength of electron-LO phonon coupling is quantitatively analyzed.

The model is applied specifically to CdS/HgS heterostructures.

Abstract

Polar optical phonons are studied in the framework of the dielectric continuum approach for a prototypical quantum-dot/quantum-well (QD/QW) heterostructure, including the derivation of the electron-phonon interaction Hamiltonian and a discussion of the effects of this interaction on the electronic energy levels. The particular example of the CdS/HgS QD/QW is addressed and the system is modelled according to the spherical geometry, considering a core sphere of material "1" surrounded by a spherically concentric layer of material "2", while the whole structure is embedded in a host matrix assumed as an infinite dielectric medium. The strength of the electron-LO phonon coupling is discussed in details and the polaronic corrections to both ground state and excited state electron energy levels are calculated. Interesting results concerning the dependence of polaronic corrections with the QD/QW structure size are analyzed.