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ASU Electronic Theses and Dissertations


This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.


Mime Type
Subject
Date Range
2012 2019


The optical valley of water, where water is transparent only in the visible range, is a fascinating phenomenon and cannot be modeled by conventional dielectric material modeling. While dielectric properties of materials can be modeled as a sum of Lorentz or Debye simple harmonic oscillators, water is the exception. In 1992 Diaz and Alexopoulos published a causal and passive circuit model that predicted the window of water by adding a “zero shunt” circuit in parallel with every Debye and Lorentz circuit branch. Other than the Diaz model, extensive literature survey yielded no universal dielectric material model that included water or …

Contributors
Alam, Shahriar, Diaz, Rodolfo E, Krause, Stephen, et al.
Created Date
2017

Achieving high efficiency in solar cells requires optimal photovoltaics materials for light absorption and as with any electrical device—high-quality contacts. Essentially, the contacts separate the charge carriers—holes at one terminal and electrons at the other—extracting them to an external circuit. For this purpose, the development of passivating and carrier-selective contacts that enable low interface defect density and efficient carrier transport is critical for making high-efficiency solar cells. The recent record-efficiency n-type silicon cells with hydrogenated amorphous silicon (a-Si:H) contacts have demonstrated the usefulness of passivating and carrier-selective contacts. However, the use of a-Si:H contacts should not be limited in just …

Contributors
Shi, Jianwei, Holman, Zachary, Bowden, Stuart, et al.
Created Date
2018

Due to the ever increasing relevance of finer machining control as well as necessary reduction in material waste by large area semiconductor device manufacturers, a novel bulk laser machining method was investigated. Because the cost of silicon and sapphire substrates are limiting to the reduction in cost of devices in both the light emitting diode (LED) and solar industries, and the present substrate wafering process results in >50% waste, the need for an improved ingot wafering technique exists. The focus of this work is the design and understanding of a novel semiconductor wafering technique that utilizes the nonlinear absorption properties …

Contributors
LeBeau, James, Bowden, Stuart, Honsberg, Christiana, et al.
Created Date
2015

Carrier lifetime is one of the few parameters which can give information about the low defect densities in today's semiconductors. In principle there is no lower limit to the defect density determined by lifetime measurements. No other technique can easily detect defect densities as low as 10-9 - 10-10 cm-3 in a simple, contactless room temperature measurement. However in practice, recombination lifetime τr measurements such as photoconductance decay (PCD) and surface photovoltage (SPV) that are widely used for characterization of bulk wafers face serious limitations when applied to thin epitaxial layers, where the layer thickness is smaller than the minority …

Contributors
Elhami Khorasani, Arash, Alford, Terry, Goryll, Michael, et al.
Created Date
2013

This work is an investigation into the information provided by the concurrent use of in situ reflection high energy electron diffraction (RHEED) and reflection electron energy loss spectroscopy (REELS). The two analytical methods were employed during growth of metal, semiconductor and superconductor thin films by molecular beam epitaxy (MBE). Surface sensitivity of the REELS spectrometer was found to be less than 1 nm for 20 KeV electrons incident at a 2 degree angle to an atomically flat film surface, agreeing with the standard electron escape depth data when adjusted incident angle. Film surface topography was found to strongly influence the …

Contributors
Strawbridge, Brett William, Newman, Nathan, Chamberlin, Ralph, et al.
Created Date
2012

It is well known that the overall performance of a solar cell is limited by the worst performing areas of the device. These areas are usually micro and nano-scale defects inhomogenously distributed throughout the material. Mitigating and/or engineering these effects is necessary to provide a path towards increasing the efficiency of state-of-the-art solar cells. The first big challenge is to identify the nature, origin and impact of such defects across length scales that span multiple orders of magnitude, and dimensions (time, temperature etc.). In this work, I present a framework based on correlative X-ray microscopy and big data analytics to …

Contributors
West, Bradley Mensing, Bertoni, Mariana I, Verebelyi, Darren, et al.
Created Date
2018

Multiple quantum well (MQW) structures have been employed in a variety of solid state devices. The InGaAs/GaAs material system is of special interest for many optoelectronic applications. This study examines epitaxial growth and defect creation in InGaAs/GaAs MQWs at its initial stage. Correlations between physical properties, crystal perfection of epitaxial structures, and growth conditions under which desired properties are achieved appear as highly important for the realization and final performance of semiconductor based devices. Molecular beam epitaxy was utilized to grow InGaAs/GaAs MQW structures with a variation in deposition temperature T<sub>dep</sub> among the samples to change crystalline and physical properties. …

Contributors
Karow, Matthias, Honsberg, Christiana B, Faleev, Nikolai N, et al.
Created Date
2014

Measurements of the geometrical magnetoresistance of a conventional semiconductor, gallium arsenide (GaAs), and a more recently developed semiconductor, iron pyrite (FeS2) were measured in the Corbino disc geometry as a function of magnetic field to determine the carrier mobility (μm). These results were compared with measurements of the Hall mobility (μH) made in the Van der Pauw configuration. The scattering coefficient (ξ), defined as the ratio between magnetoresistance and Hall mobility (μm/μH), was determined experimentally for GaAs and natural pyrite from 300 K to 4.2 K. The effect of contact resistance and heating on the measurement accuracy is discussed. Dissertation/Thesis

Contributors
Ravi, Aditya, Newman, Nathan, Singh, Rakesh, et al.
Created Date
2016

Gallium Nitride (GaN), being a wide-bandgap semiconductor, shows its advantage over the conventional semiconductors like Silicon and Gallium Arsenide for high temperature applications, especially in the temperature range from 300°C to 600°C. Development of stable ohmic contacts to GaN with low contact resistivity has been identified as a prerequisite to the success of GaN high temperature electronics. The focus of this work was primarily derived from the requirement of an appropriate metal contacts to work with GaN-based hybrid solar cell operating at high temperature. Alloyed Ti/Al/Ni/Au contact and non-alloyed Al/Au contact were developed to form low-resistivity contacts to n-GaN and …

Contributors
Zhao, Shirong, Chowdhury, Srabanti, Goodnick, Stephen, et al.
Created Date
2016

Electromigration in metal interconnects is the most pernicious failure mechanism in semiconductor integrated circuits (ICs). Early electromigration investigations were primarily focused on aluminum interconnects for silicon-based ICs. An alternative metallization compatible with gallium arsenide (GaAs) was required in the development of high-powered radio frequency (RF) compound semiconductor devices operating at higher current densities and elevated temperatures. Gold-based metallization was implemented on GaAs devices because it uniquely forms a very low resistance ohmic contact and gold interconnects have superior electrical and thermal conductivity properties. Gold (Au) was also believed to have improved resistance to electromigration due to its higher melting temperature, …

Contributors
Kilgore, Stephen, Adams, James, Schroder, Dieter, et al.
Created Date
2013