Monte-Carlo simulation of localization dynamics of excitons in ZnO and CdZnO quantum well structures

TL;DR

This study uses Monte Carlo simulations to analyze how excitons localize and hop in ZnO and CdZnO quantum wells, comparing results with experimental photoluminescence data to understand localization dynamics.

Contribution

It introduces a Monte Carlo hopping model for exciton localization in ZnO-based quantum wells, validated against experimental PL and absorption data.

Findings

Qualitative agreement between simulated and experimental PL linewidths and Stokes shifts.

Localization density consistent with low-temperature absorption spectra.

Inhomogeneous broadening affects linewidth measurements.

Abstract

Localization dynamics of excitons was studied for ZnO/MgZnO and CdZnO/MgZnO quantum wells (QW). The experimental photoluminescence (PL) and absorption data were compared with the results of Monte Carlo simulation in which the excitonic hopping was modeled. The temperature-dependent PL linewidth and Stokes shift were found to be in a qualitatively reasonable agreement with the hopping model, with accounting for an additional inhomogeneous broadening for the case of linewidth. The density of localized states used in the simulation for the CdZnO QW was consistent with the absorption spectrum taken at 5 K.