Exciton transport and thermodynamics in gallium arsenide quantum wells

This thesis describes the use of optical absorption and photoluminescence spectroscopy in understanding the spatial transport and energy relaxation of excitons in quantum well systems. I discuss the mechanism of carrier-induced changes in the absorption spectrum of a 210A GaAs multiple quantum well, and show that at moderate densities, the enhanced transmission at the heavy-hole exciton energy is due to collision broadening. I also discuss the time dependent and excitation-energy dependent energy shifts of the heavy-hole exciton. I use the changes induced in the absorption spectra due to the presence of carriers as a probe for measuring the spatial transport, and I describe the transport using an ionized-impurity scattering model. I also measure the carrier temperatures from the high energy slopes of the time-resolved photoluminescence spectra, and describe the roles of the carrier temperatures and carrier expansion on the time dynamics of the exciton luminescence intensity. In the last chapter, I study the transport properties of excitons in an asymmetric-coupled quantum well system, and explain the experimental results with a model based on interface-roughness scattering.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Yoon, Howard Wuk

• Physics, Condensed Matter
• Physics, Optics

Statement dc:rights

• Copyright 1994 Yoon, Howard Wuk

Language dc:language

eng

Identifier

AAI9503361
(UMI)AAI9503361

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21921