ASU Electronic Theses and Dissertations

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Date Range
2010 2017

Zinc oxide (ZnO), a naturally n-type semiconductor has been identified as a promising candidate to replace indium tin oxide (ITO) as the transparent electrode in solar cells, because of its wide bandgap (3.37 eV), abundant source materials and suitable refractive index (2.0 at 600 nm). Spray deposition is a convenient and low cost technique for large area and uniform deposition of semiconductor thin films. In particular, it provides an easier way to dope the film by simply adding the dopant precursor into the starting solution. In order to reduce the resistivity of undoped ZnO, many works have been done by ...

Contributors
Zhou, Bin, Tao, Meng, Goryll, Michael, et al.
Created Date
2013

Semiconductor nanolasers, as a frontier subject has drawn a great deal of attention over the past decade. Semiconductor nanolasers are compatible with on-chip integrations towards the ultimate realization of photonic integrated circuits. However, innovative approaches are strongly required to overcome the limitation of lattice-mismatch issues. In this dissertation, two alternative approaches are employed to overcome the lattice-mismatch issues. i) By taking advantage of nanowires or nanobelts techniques, flexibility in bandgap engineering has been greatly expanded, resulting in the nanolasers with wide wavelength coverage and tunability. Simultaneous two-color lasing in green and red is firstly achieved from monolithic cadmium sulfide selenide ...

Contributors
Fan, Fan, Ning, Cun-Zheng, Balanis, Constantine A, et al.
Created Date
2016

The coexistence of superconductivity and ferromagnetic orders has been the subject of study for many years. It well known that these materials possess two competing order parameters; however the two order parameters can coexist under special circumstances inducing interesting physical phenomena. In recent years the demand of ultra-low-power, high density cryogenic memories has brought considerable interest to integrate superconducting and magnetic thin films in one structure to produce novel memory elements. The operation of the device depends on the unusual electronic properties associated with the Superconductor (S) /Ferromagnetic (F) proximity effect. Niobium (Nb) based Josephson junction devices were fabricated with ...

Contributors
Abd El Qader, Makram, Newman, Nathan, Rowell, John, et al.
Created Date
2016

Group III-nitride semiconductors have been commercially used in the fabrication of light-emitting diodes and laser diodes, covering the ultraviolet-visible-infrared spectral range and exhibit unique properties suitable for modern optoelectronic applications. InGaN ternary alloys have energy band gaps ranging from 0.7 to 3.4 eV. It has a great potential in the application for high efficient solar cells. AlGaN ternary alloys have energy band gaps ranging from 3.4 to 6.2 eV. These alloys have a great potential in the application of deep ultra violet laser diodes. However, there are still many issues with these materials that remain to be solved. In this ...

Contributors
Wei, Yong, Ponce, Fernando, Chizmeshya, Andrew, et al.
Created Date
2014

Origami and Kirigami are two traditional art forms in the world. Origami, from ‘ori’ meaning folding, and ‘kami’ meaning paper is the art of paper folding. Kirigami, from ‘kiri’ meaning cutting, is the art of the combination of paper cutting and paper folding. In this dissertation, Origami and kirigami concepts were successively utilized in making stretchable lithium ion batteries and three-dimensional (3D) silicon structure which both provide excellent mechanical characteristics. Dissertation/Thesis

Contributors
Song, Zeming, Jiang, Hanqing, Dai, Lenore, et al.
Created Date
2016

In today's world there is a great need for sensing methods as tools to provide critical information to solve today's problems in security applications. Real time detection of trace chemicals, such as explosives, in a complex environment containing various interferents using a portable device that can be reliably deployed in a field has been a difficult challenge. A hybrid nanosensor based on the electrochemical reduction of trinitrotoluene (TNT) and the interaction of the reduction products with conducting polymer nanojunctions in an ionic liquid was fabricated. The sensor simultaneously measures the electrochemical current from the reduction of TNT and the conductance ...

Contributors
Diaz Aguilar, Alvaro, Tao, Nongjian, Tsui, Raymond, et al.
Created Date
2012

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

Origami and kirigami, the technique of generating three-dimensional (3D) structures from two-dimensional (2D) flat sheets, are now more and more involved in scientific and engineering fields. Therefore, the development of tools for their theoretical analysis becomes more and more important. Since much effort was paid on calculations based on pure mathematical consideration and only limited effort has been paid to include mechanical properties, the goal of my research is developing a method to analyze the mechanical behavior of origami and kirigami based structures. Mechanical characteristics, including nonlocal effect and fracture of the structures, as well as elasticity and plasticity of ...

Contributors
Lv, Cheng, Jiang, Hanqing, Yu, Hongbin, et al.
Created Date
2016

Inductors are fundamental components that do not scale well. Their physical limitations to scalability along with their inherent losses make them the main obstacle in achieving monolithic system-on-chip platform (SoCP). For past decades researchers focused on integrating magnetic materials into on-chip inductors in the quest of achieving high inductance density and quality factor (QF). The state of the art on-chip inductor is made of an enclosed magnetic thin-film around the current carrying wire for maximum flux amplification. Though the integration of magnetic materials results in enhanced inductor characteristics, this approach has its own challenges and limitations especially in power applications. ...

Contributors
Khdour, Mahmoud M., Yu, Hongbin, Pan, George, et al.
Created Date
2014

This dissertation aims to study and understand relevant issues related to the electronic, spin and valley transport in two-dimensional Dirac systems for different given physical settings. In summary, four key findings are achieved. First, studying persistent currents in confined chaotic Dirac fermion systems with a ring geometry and an applied Aharonov-Bohm flux, unusual whispering-gallery modes with edge-dependent currents and spin polarization are identified. They can survive for highly asymmetric rings that host fully developed classical chaos. By sustaining robust persistent currents, these modes can be utilized to form a robust relativistic quantum two-level system. Second, the quantized topological edge states ...

Contributors
XU, HONGYA, Lai, Ying-Cheng, Bliss, Daniel, et al.
Created Date
2017

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.