Electron-phonon Interaction in Non-polar Quantum Dots Induced by the Amorphous Polar Environment

TL;DR

This paper introduces a new energy relaxation mechanism for electrons in non-polar quantum dots caused by interactions with the electric fields from surrounding amorphous polar environments, relevant for Si nanocrystals in SiO2.

Contribution

It presents a novel mechanism of electron energy relaxation via interaction with local vibrational electric fields in amorphous polar surroundings, applicable to non-polar quantum dots.

Findings

Mechanism controls energy relaxation in Si nanocrystals.

Conventional electron-phonon interactions are ineffective here.

The proposed interaction explains relaxation in non-polar quantum dots.

Abstract

We propose a mechanism of energy relaxation for carriers confined in a non-polar quantum dot surrounded by an amorphous polar environment. The carrier transitions are due to their interaction with the oscillating electric field induced by the local vibrations in the surrounding amorphous medium. We demonstrate that this mechanism controls energy relaxation for electrons in Si nanocrystals embedded in a SiO$_2$ matrix, where conventional mechanisms of electron-phonon interaction are not efficient.