Undergraduate Honors Theses

Thesis Defended

Winter 2015

Document Type

Thesis

Type of Thesis

Departmental Honors

Department

Physics

First Advisor

Steven Cundiff

Abstract

Despite the short timescales on which electron dynamics occur in semiconductor nanostructures, much insight into these processes can be provided by studying them using linear, long timescale, spectroscopy. For instance, manufacturing processes unintentionally introduce fluctuations in the width of semiconductor quantum wells. These fluctuations subtly modulate the optical emission energies of electrons confined within the quantum well layers. It is therefore imperative to quantify these width fluctuations so their effect on electron confinement potentials can be accounted for in ultrafast spectroscopic studies of semiconductor quantum wells. The use of linear micro-photoluminescence spectroscopy makes quantifying this disorder possible. Additionally, coupling between electron states in asymmetric double quantum wells is of fundamental interest. Understanding incoherent, long-timescale electron coupling in this system allows us to provide insight into the dominant physical mechanisms that govern exciton coupling in general. For example, understanding the thermal mediation of coupling between wells could allow researchers to better model and predict electron behavior in useful semiconductor devices like solar cells and photodiodes. In this thesis, I present the development of micro-photoluminesence spectroscopy to study spatial disorder in semiconductor quantum wells. Additionally, I present the development of photoluminescence excitation spectroscopy to study the long-timescale, incoherent exciton coupling between adjacent wells in an asymmetric quantum well heterostructure.

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