Sub-wetting layer continuum states in quantum dot samples

TL;DR

This paper investigates how the coupling between extended wetting-layer states and localized quantum dot states affects optical spectra, focusing on the sub-wetting layer continuum in polar semiconductor quantum dot samples.

Contribution

It provides a theoretical analysis of Froehlich's electron-phonon coupling's role in the sub-wetting layer continuum and state broadening in quantum dot optical spectra.

Findings

Froehlich's coupling contributes to the sub-wetting layer continuum.

The interaction influences the broadening of localized states.

Theoretical estimates align with experimental observations.

Abstract

In the polar semiconductor samples of the self-organized quantum dots, grown by the Stranski-Krastanow growth method, the lowest energy extended states of the electronic excitations are assumed to be the wetting-layer states. The coupling between these extended states and the electronic states localized in the individual quantum dots, may influence the optical spectra of such samples in the sub-wetting layer region of energy. This effect is studied assuming the Froehlich's coupling between the electrons and polar optical phonons. The contribution of this interaction to the appearence of the sub-wetting layer continuum in the optical spectra and to the level broadening of the localized states, pointed out in some experiments, is estimated.