Engineering Commons^™

Fabrication Of Silver-Doped Zinc Oxide Thin Films Through Optimized Sol-Gel Deposition And Nanoparticle Wetting Process, Reed T. Heintzkill

Theses and Dissertations

Zinc Oxide (ZnO) has been of significant interest as a Transparent Conductive Oxide (TCO) given its sizable direct band-gap, and as a potential substitute for Indium-Tin Oxide for use in opto-electronic and piezo-electric devices, due to its comparatively abundant and nontoxic precursor materials. Sol-gel processing is an easy, low-energy method for fabricating ZnO thin films, and there has been increasing interest in doping the compound such to give it p-type semiconductive character.

This thesis thoroughly investigates sol-gel processing of ZnO thin solid films, with focus on wet-chemistry (sol-gel) methods of doping the material with silver (both as elemental ions and …

Physical Electronic Properties Of Self-Assembled 2d And 3d Surface Mounted Metal-Organic Frameworks, Radwan Elzein

USF Tampa Graduate Theses and Dissertations

Metal-organic frameworks stand at the frontiers of molecular electronic research because they combine desirable physical properties of organic and inorganic components. They are crystalline porous solids constructed by inorganic nodes coordinated to organic ligands to form 1D, 2D, or 3D structures. They possess unique characteristics such as ultrahigh surface area crystal lattices up to 10000 m² g^-1, and tunable nanoporous sizes ranging from 0.2 to 50 nm. Their unprecedented structural diversity and flexibility beyond solid state materials can lead to unique properties such as tailorable electronic and ionic conductivity which can serve as interesting platforms for a …

Solid Solution Strengthened Fe Alloys, Sidharth Krishnamoorthi, Ruizhe Su, Yifan Zhang, Xinghang Zhang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Iron (Fe)-based alloys (such as steel) are widely used structural materials in industry. Numerous methods have been applied to improve their mechanical properties. In this study, we used a technique know as magnetron sputtering to deposit various Fe-based binary alloy coatings to investigate the influence of solutes on solid solution hardening. Several factors contribute to the solid solution hardening of the alloys, such as composition, atomic radius, modulus, and lattice parameter. After preliminary calculations and analysis, we selected several solutes, including molybdenum (Mo), niobium (Nb), and zirconium (Zr). The compositions of solutes were varied to be 2.5, 5, 8 atomic …

In Situ Extrinsic Doping Of Cdte Thin Films For Photovoltaic Applications, Imran Suhrid Khan

USF Tampa Graduate Theses and Dissertations

The Cadmium Telluride thin film solar cell is one of the leading photovoltaic technologies. Efficiency improvements in the past decade made it a very attractive and practical source of renewable energy. Considering the theoretical limit, there is still room for improvement, especially the cell’s open circuit voltage (VOC). To improve VOC, the p-type carrier concentration and minority carrier lifetime of the CdTe absorber needs to be improved. Both these parameters are directly related to the point defect distribution of the semiconductor, which is a function of deposition stoichiometry, dopant incorporation and post-deposition treatments.

CdTe films were deposited by the Elemental …

Driven Morphological Evolution Of Crystal Surfaces, Epitaxial Thin Films, And Two-Dimensional Materials: Morphological Stability And Pattern Formation, Lin Du

Doctoral Dissertations

Properly controlled applied fields can stabilize planar surface morphology, reduce surface roughness, and drive the formation of intriguing nanoscale morphological features, providing a path toward precise nanopatterning for the development of electronic and photonic materials with optimal functionality. To study the surface morphological evolution of stressed crystalline solids and thin films, we have established a continuum model accounting for stresses, electric fields, temperature gradients, surface energy, wetting potential, and surface diffusional anisotropy. Based on linear stability analysis and self-consistent dynamical simulations, we found that long-wavelength plane-wave perturbations to a planar surface of a uniaxially stressed solid can trigger a nonlinear …

Electrodeposited Semiconductor Nanostructures & Epitaxial Thin Films For Flexible Electronics, Naveen Kumar Mahenderkar

Doctoral Dissertations

"Single-crystal Si is the bedrock of semiconductor devices due to the high crystalline perfection which minimizes electron-hole recombination, and the dense native silicon oxide which minimizes surface states. To expand the palette of electronic materials beyond planar Si, an inexpensive source of highly ordered material is needed that can serve as an inert substrate for the epitaxial growth of grain boundary-free semiconductors, photonic materials, and superconductors. There is also a need for a simple, inexpensive, and scalable fabrication technique for the growth of semiconductor nanostructures and thin films. This dissertation focuses on the fabrication of semiconducting nanowires (polycrystalline Ge & …

Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe

Open Access Theses & Dissertations

Hafnium oxide, or hafnia, is a high temperature refractory material with good electrical, chemical, optical, and thermodynamic properties. The effects of dopants have been widely studied, especially after the discovery of ferroelectricity induced in hafnia thin films. While attractive and used in the opto-electronic, memory devices, and semiconductor industries, there is a lack in the literature on enhancing the mechanical properties of hafnium oxide, specifically through doping it with tungsten, another material of interest particularly for future high temperature device applications. Thus, this work aimed to grow hafnia thin films doped with varying amounts of tungsten. The samples were grown …