Exciton-optical-phonon coupling: comparison with experiments for ZnO quantum wells

TL;DR

This study investigates how exciton-LO phonon coupling in ZnO quantum wells varies with temperature and well width, revealing that confinement enhances excitonic binding energy and reduces coupling strength.

Contribution

It provides experimental measurements of exciton-LO phonon coupling in ZnO quantum wells and explains the reduction in coupling due to quantum confinement effects.

Findings

Coupling strength decreases with decreasing well width.

Excitonic binding energy increases due to quantum confinement.

Temperature affects linewidths and coupling in ZnO quantum wells.

Abstract

The temperature-dependent linewidths of excitons in ZnO quantum wells were studied by measuring absorption spectra from 5 K to room temperature. We deduced experimentally the exciton-longitudinal-optical (LO) phonon coupling strength, which showed reduction of coupling with decrease in well width. This reduction was explained in terms of confinement-induced enhancement of the excitonic binding energy by comparing the binding energy dependence of calculated coupling strength.