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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.


Language
  • English
Date Range
2011 2019


In semiconductor physics, many properties or phenomena of materials can be brought to light through certain changes in the materials. Having a tool to define new material properties so as to highlight certain phenomena greatly increases the ability to understand that phenomena. The generalized Monte Carlo tool allows the user to do that by keeping every parameter used to define a material, within the non-parabolic band approximation, a variable in the control of the user. A material is defined by defining its valleys, energies, valley effective masses and their directions. The types of scattering to be included can also be …

Contributors
Hathwar, Raghuraj, Vasileska, Dragica, Goodnick, Stephen M, et al.
Created Date
2011

Infrared photodetectors, used in applications for sensing and imaging, such as military target recognition, chemical/gas detection, and night vision enhancement, are predominantly comprised of an expensive II-VI material, HgCdTe. III-V type-II superlattices (SLs) have been studied as viable alternatives for HgCdTe due to the SL advantages over HgCdTe: greater control of the alloy composition, resulting in more uniform materials and cutoff wavelengths across the wafer; stronger bonds and structural stability; less expensive substrates, i.e., GaSb; mature III-V growth and processing technologies; lower band-to-band tunneling due to larger electron effective masses; and reduced Auger recombination enabling operation at higher temperatures and …

Contributors
Steenbergen, Elizabeth H., Zhang, Yong-Hang, Brown, Gail J., et al.
Created Date
2012

ABSTRACT This work seeks to develop a practical solution for short range ultrasonic communications and produce an integrated array of acoustic transmitters on a flexible substrate. This is done using flexible thin film transistor (TFT) and micro electromechanical systems (MEMS). The goal is to develop a flexible system capable of communicating in the ultrasonic frequency range at a distance of 10 - 100 meters. This requires a great deal of innovation on the part of the FDC team developing the TFT driving circuitry and the MEMS team adapting the technology for fabrication on a flexible substrate. The technologies required for …

Contributors
Daugherty, Robin Louis, Allee, David R, Chae, Junseok, et al.
Created Date
2012

Nonvolatile memory (NVM) technologies have been an integral part of electronic systems for the past 30 years. The ideal non-volatile memory have minimal physical size, energy usage, and cost while having maximal speed, capacity, retention time, and radiation hardness. A promising candidate for next-generation memory is ion-conducting bridging RAM which is referred to as programmable metallization cell (PMC), conductive bridge RAM (CBRAM), or electrochemical metallization memory (ECM), which is likely to surpass flash memory in all the ideal memory characteristics. A comprehensive physics-based model is needed to completely understand PMC operation and assist in design optimization. To advance the PMC …

Contributors
Rajabi, Saba, Barnaby, Hugh, Kozicki, Michael, et al.
Created Date
2014

GaAs single-junction solar cells have been studied extensively in recent years, and have reached over 28 % efficiency. Further improvement requires an optically thick but physically thin absorber to provide both large short-circuit current and high open-circuit voltage. By detailed simulation, it is concluded that ultra-thin GaAs cells with hundreds of nanometers thickness and reflective back scattering can potentially offer efficiencies greater than 30 %. The 300 nm GaAs solar cell with AlInP/Au reflective back scattering is carefully designed and demonstrates an efficiency of 19.1 %. The device performance is analyzed using the semi-analytical model with Phong distribution implemented to …

Contributors
Liu, Shi, Zhang, Yong-Hang, Johnson, Shane R, et al.
Created Date
2015

High-performance III-V semiconductors based on ternary alloys and superlattice systems are fabricated, studied, and compared for infrared optoelectronic applications. InAsBi is a ternary alloy near the GaSb lattice constant that is not as thoroughly investigated as other III-V alloys and that is challenging to produce as Bi has a tendency to surface segregate and form droplets during growth rather than incorporate. A growth window is identified within which high-quality droplet-free bulk InAsBi is produced and Bi mole fractions up to 6.4% are obtained. Photoluminescence with high internal quantum efficiency is observed from InAs/InAsBi quantum wells. The high structural and optical …

Contributors
Webster, Preston Thomas, Johnson, Shane R, Zhang, Yong-Hang, et al.
Created Date
2016

This work demonstrates novel nBn photodetectors including mid-wave infrared (MWIR) nBn photodetectors based on InAs/InAsSb type-II superlattices (T2SLs) with charge as the output signal, and visible nBn photodetectors based on CdTe with current output. Furthermore, visible/MWIR two-color photodetectors (2CPDs) are fabricated through monolithic integration of the CdTe nBn photodetector and an InSb photodiode. The MWIR nBn photodetectors have a potential well for holes present in the barrier layer. At low voltages of < −0.2 V, which ensure low dark current <10-5 A/cm2 at 77 K, photogenerated holes are collected in this well with a storage lifetime of 40 s. This …

Contributors
He, Zhaoyu, Zhang, Yong-Hang, Vasileska, Dragica, et al.
Created Date
2016

Polycrystalline CdS/CdTe solar cells continue to dominate the thin-film photovoltaics industry with an achieved record efficiency of over 22% demonstrated by First Solar, yet monocrystalline CdTe devices have received considerably less attention over the years. Monocrystalline CdTe double-heterostructure solar cells show great promise with respect to addressing the problem of low Voc with the passing of the 1 V benchmark. Rapid progress has been made in driving the efficiency in these devices ever closer to the record presently held by polycrystalline thin-films. This achievement is primarily due to the utilization of a remote p-n heterojunction in which the heavily doped …

Contributors
Becker, Jacob, Zhang, Yong-Hang, Bertoni, Mariana, et al.
Created Date
2017

Silicon photovoltaics is the dominant contribution to the global solar energy production. As increasing conversion efficiency has become one of the most important factors to lower the cost of photovoltaic systems, the idea of making a multijunction solar cell based on a silicon bottom cell has attracted broad interest. Here the potential of using dilute nitride GaNPAs alloys for a lattice-matched 3-terminal 2-junction Si-based tandem solar cell through multiscale modeling is investigated. To calculate the electronic band structure of dilute nitride alloys with relatively low computational cost, the sp^3 d^5 s^* s_N tight-binding model is chosen, as it has been …

Contributors
Zou, Yongjie, Goodnick, Stephen M., Honsberg, Christiana B., et al.
Created Date
2019