Engineering Commons^™

Transport, Photoluminescence & Photoconduction Characteristics Of Free Standing Two-Dimensional Γ-Alumina & Titanium Superlattice Doped Two-Dimensional Γ-Alumina Grown By Graphene-Assisted Atomic Layer Deposition, Elaheh Kheirandish

Theses and Dissertations

This study presents a facile high-yield bottom-up fabrication, morphology, crystallographic and optoelectronic characterization of free-standing quasi-2D γ-alumina, a non van der Waals 2D material. The synthesis comprises a multi-cycle atomic layer deposition (ALD) of amorphous alumina on a porous interconnected graphene foam as a growth scaffold and removed next by annealing and sintering the alumina/graphene/alumina sandwich at ~ 800 °C in air . The crystallographic and structural characteristics of the formed non-van der Waals quasi 2D γ-alumina were studied by X-ray diffraction (XRD), selected area electron diffraction (SAED), and high-resolution transmission electron microscopy (HRTEM). This analysis revealed the synthesized 2D …

Application Of In Situ And Ex Situ Characterization Of Atomic Layer Deposition Processes For Gallium Phosphide And Sodium Fluoride, Sara Rose Kuraitis

Boise State University Theses and Dissertations

Atomic layer deposition (ALD) is a vapor deposition technique for synthesizing thin films with nanometer thickness control. ALD films are deposited on a substrate surface in a cyclic layer-by-layer fashion utilizing alternating doses of highly reactive chemical precursors. Precursors are selected to undergo self-limiting chemical reactions with the surface, and desired film thickness is achieved by varying the number of ALD cycles accordingly. Optimization of ALD process parameters and precursor chemistry enables conformal coating of arbitrary substrate geometries, including high aspect ratio features such as trenches. In the decades since its introduction, ALD has been used for applications across many …

Rf Mems Resonators For Mass Sensing Applications, Ivan Fernando Rivera

USF Tampa Graduate Theses and Dissertations

Sensing devices developed upon resonant microelectromechanical and nanoelectromechanical (M/NEMS) system technology have become one of the most attractive areas of research over the past decade. These devices make exceptional sensing platforms because of their miniscule dimensions and resonant modes of operation, which are found to be extremely sensitive to added mass. Along their unique sensing attributes, they also offer foundry compatible microfabrication processes, low DC power consumption, and CMOS integration compatibility. In this work, electrostatically and piezoelectrically actuated RF MEMS bulk resonators have been investigated for mass sensing applications. The capacitively-transduced resonators employed electrostatic actuation to achieve desired resonance mode …

Development Of Electroplated-Ni Structured Micromechanical Resonators For Rf Application, Mian Wei

USF Tampa Graduate Theses and Dissertations

On-chip vibrating MEMS resonators with high frequency-Q product on par with that of the off-chip quartz crystals have attracted lots of attention from both academia and industry for applications on sensing, signal processing, and wireless communication. Up to now, several approaches for monolithic integration of MEMS and transistors have been demonstrated. Vibrating micromechanical disk resonators which utilize electroplated nickel as the structural material along with either a solid-gap high-k dielectric capacitive transducer or a piezoelectric transducer have great potential to offer unprecedented performance and capability of seamless integration with integrated circuits.

Despite the frequency drift problems encountered in early attempts …

Integrated Electrostatically- And Piezoelectrically-Transduced Contour-Mode Mems Resonator On Silicon-On-Insulator (Soi) Wafer, I-Tsang Wu

USF Tampa Graduate Theses and Dissertations

Due to the recent rapid growth in personal mobile communication devices (smartphones, PDA's, tablets, etc.), the wireless market is always looking for new ways to further miniaturize the RF front-ends while reducing the cost and power consumption. For many years, wireless transceivers and subsystems have been relying on high quality factor (Q) passives (e.g., quartz crystal, ceramics) to implement oscillators, filters, and other key RF front-end circuitry elements. However, these off-chip discrete components occupy large chip area and require power-demanding interfacing circuits. As a result, a great deal of research effort has been devoted to the development of …

Nanowire Zinc Oxide Mosfet Pressure Sensor, William Clavijo

Theses and Dissertations

Fabrication and characterization of a new kind of pressure sensor using self-assembly Zinc Oxide (ZnO) nanowires on top of the gate of a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is presented. Self-assembly ZnO nanowires were fabricated with a diameter of 80 nm and 800 nm height (80:8 aspect ratio) on top of the gate of the MOSFET. The sensor showed a 110% response in the drain current due to pressure, even with the expected piezoresistive response of the silicon device removed from the measurement. The pressure sensor was fabricated through low temperature bottom up ultrahigh aspect ratio ZnO nanowire growth using anodic …

Zno Nanostructures: Growth, Characterization And Applications, Mikhail Ladanov

USF Tampa Graduate Theses and Dissertations

ZnO nanostructures have been investigated for quite a long time. However, only recently they triggered much interest due to advances in materials synthesis and characterization, as well as emerging demand for new nanostructured materials in novel device implementations.

A large part of the work was devoted to exploring new methodology for patterning growth sites and controlling nanowires morphology using the deposition methods that are compatible with integrated circuits (IC) processing. Microcontact printing was used to pattern the seeding layer, and, subsequently, ZnO nanowires through a resistless soft lithography process.

When considering hydrothermal growth of ZnO nanowires in the framework of …

V2o5-Wo3 Composite Films And Surface-Coated Licoo2 For Enhanced Li-Ion Intercalation Properties, Chuan Cai

LSU Master's Theses

We have investigated the enhanced Li-ion intercalation properties of two different materials, which are V2O5-WO3 composite and surface-coated LiCoO2. A simple and novel solution processing method is employed to prepare V2O5-WO3 composite films that demonstrate enhanced Li-ion intercalation properties for applications in Li-ion batteries or electrochromic displays. This solution processing method employs precursors that only contain the elements of V, W, O and H, which avoids impurity elements such as Na that has been commonly used in other solution methods (e.g. using precursors of sodium metavanadate and sodium tungstate solution). The V2O5-WO3 composite films show enhanced Li-ion intercalation properties compared …