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Full-Text Articles in Nanotechnology Fabrication

Carbon Nanotube Field Emission Arrays, Benjamin L. Crossley Jun 2011

Carbon Nanotube Field Emission Arrays, Benjamin L. Crossley

Theses and Dissertations

This effort exploits the unique physical and electrical characteristics of carbon nanotubes (CNTs) for field emission applications. Carbon nanotube field emission devices are designed, fabricated, and tested. Two reliable CNT synthesis methods, microwave plasma enhanced chemical vapor deposition (MPE-CVD) and thermal chemical vapor deposition (T-CVD), are developed. The physical properties of the resulting CNTs are analyzed using Raman spectroscopy and Scanning electron microscopy (SEM) and then tested for field emission performance. The T-CVD grown CNTs are shown to have fewer growth defects, but suffer from less process control making integration into devices difficult without further process development. Field emission testing …


Fabrication And Study Of Molecular Devices And Photovoltaic Devices By Metal/Dielectric/Metal Structures, Bing Hu Jan 2011

Fabrication And Study Of Molecular Devices And Photovoltaic Devices By Metal/Dielectric/Metal Structures, Bing Hu

University of Kentucky Doctoral Dissertations

A new class of electrodes with nanometer-scale contact spacing can be produced at the edge of patterned metal/insulator/metal this film structures. A key challenge is to produce insulator layers with low leakage current and have pristine metal contacts for controlled molecular contacts. Atomic layer deposition of high quality Al2O3 thin films onto Au electrodes was enabled by surface modification with a self-assembled monolayer of -OH groups that react with a monolayer of trimethylaluminum gas source. Ar ion milling was then used to expose the edge of the Au/dielectric/Au structure for molecular electrode contacts. The junctions are characterized …


Synthesis, Characterization And Simulation Of Optical And Raman Properties Of Metal Nanoparticles, Sriteja Yamparala Dec 2010

Synthesis, Characterization And Simulation Of Optical And Raman Properties Of Metal Nanoparticles, Sriteja Yamparala

UNLV Theses, Dissertations, Professional Papers, and Capstones

Metal nanoparticles are of strong interest for their unusual optical and Raman properties with potential for new and improved device applications. Specifically, the significantly enhanced Raman Scattering enabled by Surface Plasmon Resonance on metal nanoparticles open up the potential for the implementation of very sensitive sensors. It has been demonstrated that Surface Plasmon resonance can be used for the detection of a single molecule. Out of the various metal nanoparticles that have been investigated, the most promising are that made of gold and silver. Metal nananoparticles of gold and silver show strong Raman enhancement in the visible spectral region, making …


Optimization Of Alternating Current Electrothermal Micropump By Numerical Simulation, Quan Yuan Aug 2010

Optimization Of Alternating Current Electrothermal Micropump By Numerical Simulation, Quan Yuan

Masters Theses

Microfluidic technology has been grown rapidly in the past decade. Microfluidics can find wide applications in multiple fields such as medicine, electronics, chemical and biology. Micro-pumping is an essential part of a microfluidic system. This thesis presents the optimization process of AC electro-thermal micropump with respect to the geometry of electrode array and channel height.

The thesis first introduces the theories of AC electrokinetic including dielectrophoresis, AC electro-osmosis (ACEO) and AC electro-thermal (ACET). Also presented are the basic theory and governing equations of microfluidics, the continuity equation, the Navier-Stokes equation, and the conservation of energy equation. AC electro-thermal effect results …


Fabrication, Characterization And Simulation Of Non-Lithographic Nanostructures And Their Potential Applications, Neelanjan Bhattacharya Aug 2010

Fabrication, Characterization And Simulation Of Non-Lithographic Nanostructures And Their Potential Applications, Neelanjan Bhattacharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

The dissertation describes the formation of porous silicon through the pores of porous alumina on a silicon substrate. Porous silicon, by itself, is inherently a non-uniform material that has non-uniform optical and electronic properties. In addition, it is also mechanically fragile material requiring careful material handling. The porous silicon fabricated through the nanosized pores of porous alumina are expected to mitigate these problems, thereby enhancing commercial viability of the device. The porous silicon as well the porous alumina have been synthesized through anodisation for various parameters and also various types of anodizing electrolytes. The porous silicon, so obtained have been …


The Applications And Limitations Of Printable Batteries, Matthew Delmanowski Jun 2010

The Applications And Limitations Of Printable Batteries, Matthew Delmanowski

Graphic Communication

This study focuses on the potential applications for printed batteries and how they could affect the printing industry. It also analyzes the main problems associated with manufacturing this technology and what needs to be done to overcome these issues. To find the answers to these questions, two methods of research were used. The first was through the elite and specialized interviewing of Dr. Scott Williams of Rochester Institute of Technology and Professor Nancy Cullins from Cal Poly. The second form of research was a common, yet useful, method called secondary research. This entailed looking at recent written research papers about …


Enhanced Light Extraction Efficiency From Gan Light Emitting Diodes Using Photonic Crystal Grating Structures, Simeon S. Trieu Jun 2010

Enhanced Light Extraction Efficiency From Gan Light Emitting Diodes Using Photonic Crystal Grating Structures, Simeon S. Trieu

Master's Theses

Gallium nitride (GaN) light emitting diodes (LED) embody a large field of research that aims to replace inefficient, conventional light sources with LEDs that have lower power, higher luminosity, and longer lifetime. This thesis presents an international collaboration effort between the State Key Laboratory for Mesoscopic Physics in Peking University (PKU) of Beijing, China and the Electrical Engineering Department of California Polytechnic State University, San Luis Obispo. Over the course of 2 years, Cal Poly’s side has simulated GaN LEDs within the pure blue wavelength spectrum (460nm), focusing specifically on the effects of reflection gratings, transmission gratings, top and bottom …


Towards A Universal Ultra-Thin Fluorinated Diamond-Like Carbon Coating For Nanoimprint Lithography Imprinters, Ryan Winfield Fillman Aug 2009

Towards A Universal Ultra-Thin Fluorinated Diamond-Like Carbon Coating For Nanoimprint Lithography Imprinters, Ryan Winfield Fillman

Theses and Dissertations

Nanoimprint lithography (NIL) has proven to achieve arbitrary, nanoscale features, over large areas, without the use of costly step-and-repeat UV lithography tools. The fidelity of the imprinted pattern depends on the elimination of the adhesion between the imprinted polymer and the imprinter upon withdrawal of the imprinter. The plasma deposition of a layer of fluorinated diamond-like carbon (F-DLC) has proven to be a successful anti-adhesion layer but in the past has required an entire diamond-like carbon (DLC) substrate. The requirement that the imprinter be made of DLC limits the imprinter processing and can limit the capabilities of NIL. DLC films …


Fabrication Of Nanostructures For Improved Performance Of Electrochemical Sensors And For Reference Compensation In Localized Surface Plasmon Resonance Sensors, Prashanthi Para Jan 2009

Fabrication Of Nanostructures For Improved Performance Of Electrochemical Sensors And For Reference Compensation In Localized Surface Plasmon Resonance Sensors, Prashanthi Para

University of Kentucky Master's Theses

L‐glutamate is associated with several neurological disorders; thus, monitoring fast dynamics of L‐glutamate is of great importance in the field of neuroscience. Electrode miniaturization demanded by many applications leads to reduced surface area and decreased amounts of immobilized enzymes on coated electrodes. As a result, lower signal‐to‐noise ratios are observed for oxidase‐enzyme based sensors. To increase the signal‐to‐noise ratio we have developed a process to fabricate micro‐ and nano‐ structures on the microelectrode surface.

Localized surface‐plasmon resonances (SPR) has been extensively used to design label‐free biosensors that can monitor receptor‐ligand interactions. A major challenge with localized SPR sensors is that …


Individual Copper Nanowire Decorated By Gold Nanoparticles For Surface Enhanced Raman Scattering, Roshan Guttikonda Jan 2009

Individual Copper Nanowire Decorated By Gold Nanoparticles For Surface Enhanced Raman Scattering, Roshan Guttikonda

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this Thesis, I discuss the theory, implementation and applications of Surface enhanced Raman scattering (SERS). Surface enhanced Raman scattering has been used to detect 4 mercaptopyridine molecules. On a Silicon wafer, Gold nanoparticles are deposited onto Copper nanowires. Hotspots occur at the small gap (less than 10nm) between the nanowire and nanoparticle. The interaction of the electromagnetic field of the incident laser and the surface plasmon resonances of the metal nanoparticles at the hot spots enhances the Raman scattering signal of the adsorbed pyridine molecule (10 -3 M ). The dependence of SERS signal on the polarization angle of …