Nanotechnology Fabrication Commons^™

Memristor-Based Reservoir Computing, Manjari S. Kulkarni

Dissertations and Theses

In today's nanoscale era, scaling down to even smaller feature sizes poses a significant challenge in the device fabrication, the circuit, and the system design and integration. On the other hand, nanoscale technology has also led to novel materials and devices with unique properties. The memristor is one such emergent nanoscale device that exhibits non-linear current-voltage characteristics and has an inherent memory property, i.e., its current state depends on the past. Both the non-linear and the memory property of memristors have the potential to enable solving spatial and temporal pattern recognition tasks in radically different ways from traditional binary transistor-based …

Nanoparticle Necklace Network Arrays Exhibiting Room Temperature Single-Electron Switching, Jennifer L. Kane

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

A single nanoparticle is one of the most sensitive electronic devices for sensing chemicals in a gas or liquid. The conductivity of a single Au nanoparticle is significantly modulated by the binding of a molecule that alters charge by just one electron. However, the single-electron sensitivity requires cryogenic temperatures and interconnection is not easy. A patterned two-dimensional network of one-dimensional nanoparticle necklaces made up of 10 nm Au particles are fabricated and shown to exhibit similar single-electron effect at room temperature. Furthermore, the long range conductivity of over 10’s of microns makes the structure easy to self-assemble onto conventional microelectronics …

Fabrication Of Composite Nanomaterials For Thin Film Amorphous Silicon Solar Cells, Benjamin Seth Newton

Graduate Theses and Dissertations

A material with the precise combination of amorphous silicon and polycrystalline silicon would be able to take advantage of the high absorption capabilities of amorphous silicon and the electron transport capabilities of polycrystalline silicon. Polycrystalline nanostructures in the form of wires can also take advantage of other properties of light absorption, trapping and scattering inherent in nanowire structures. These properties of high absorption and electron transport in one device would lead to advances in the search for highly efficient low cost solar cells and sensors. In this work a thin film material composed of an array of polycrystalline silicon nanostructures …

Fabrication Of Horizontal Silicon Nanowires Using A Thin Aluminum Film As A Catalyst, Khaja Hafeezuddin Mohammed

Graduate Theses and Dissertations

Silicon nanowires have been the topic of research in recent years for their significant attention from the electronics industry to grow even smaller electronic devices. The semiconductor industry is built on silicon. Silicon nanowires can be the building blocks for future nanoelectronic devices. Various techniques have also been reported in fabricating the silicon nanowires. But most of the techniques reported, grow vertical silicon nanowires. In the semiconductor industry, integrated circuits are designed and fabricated in a horizontal architecture i.e. the device layout is flat compared to the substrate. When vertical silicon nanowires are introduced in the semiconductor industry, a whole …

Photodetectors And Photovoltaic Devices Based On Semiconductor Nanomaterials, Jiang Wu

Graduate Theses and Dissertations

Photodetectors based various nanostructures and plasmon enhanced solar cells are investigated in this dissertation. The motivation of the dissertation rise is driven by urgent need of both high efficiency photodetectors and solar cells.

First, quantum dot infrared photodetectors have been intensely investigated due to their promise in high performance photodetectors. However, the strain-driven growth of quantum dots has hindered the progress of quantum dot photodetectors. The presence of strain in the device presents complexity in designing as well as defects. Therefore, in this project, new designs of quantum dot photodetector structures are presented to improve the control over detection wavelength. …

In-Situ Ellipsometry Characterization Of Anodically Grown Silicon Dioxide And Lithium Intercalation Into Silicon, Eric A. Montgomery

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this thesis, in-situ ellipsometry and electroanalytical investigations of two electrochemical processes are reported: including the formation of anodically grown silicon dioxide and the intercalation of lithium into silicon. Analysis of the ellipsometry data shows that the anodically grown silicon dioxide layer is uniform and has similar properties as thermally grown silicon dioxide. The lithium-ion intercalation data reveals non-uniform thin film formation, which requires further studies and development of appropriate ellipsometric optical models.

Advisers: Eva Schubert and Mathias Schubert

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 …

Nano-Engineered High-Performance Magneto-Optic Garnet Materials, Mohammad Nur-E-Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh

ECU Presentations

No abstract provided.

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 …

Nanofabrication Of Surface-Enhanced Raman Scattering Device By An Integrated Block-Copolymer And Nanoimprint Lithography Method, E. L. Yang, C. C. Liu, C. Y.P. Yang, P. F. Nealey, C. A. Steinhaus, Jack L. Skinner

Mechanical Engineering

The integration of block-copolymers and nanoimprint lithography presents a novel and cost-effective approach to achieving nanoscale patterning capabilities. The authors demonstrate the fabrication of a surface-enhanced Raman scattering device using templates created by the block-copolymers nanoimprint lithography integrated method.

Generalized Ellipsometry On Sculptured Thin Films Made By Glancing Angle Deposition, Daniel Schmidt

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this thesis, physical properties of highly optically and magnetically anisotropic metal sculptured thin films made by glancing angle deposition are presented. Predominantly, the determination of optical and magneto-optical properties with spectroscopic generalized Mueller matrix ellipsometry and homogenization approaches is discussed. Nomenclatures are proposed to unambiguously identify the sculptured thin film geometry.

Generalized ellipsometry, a non-destructive optical characterization technique, is employed to determine geometrical structure and anisotropic dielectric properties of highly spatially coherent three-dimensionally nanostructured thin films in the spectral range from 400 to 1700 nm. The analysis of metal slanted columnar thin films (F1-STFs) deposited at glancing angle ( …

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 …

Nanoindentation And Plasticity In Nanocrystalline Ni Nanowires: A Case Study In Size Effect Mitigation, F. Sansoz, Virginie Rollin

Publications

We examine the processes of spherical indentation and tension in Ni nanowires and thin films containing random distributions of nanoscale grains by molecular dynamics simulations. It is shown that the resistance to nanoindentation of nanocrystalline Ni nanowires with diameters of 12 and 30 nm tends not to depend on the wire diameter and free surfaces, contrary to nanoindentation in single-crystalline nanowires. Accommodation of plastic deformation by grain boundary sliding suggests a mitigation strategy for sample boundary effects in nanoscale plasticity.

Magneto-Optical Visualisation For High-Resolution Forensic Data Recovery Using Advanced Thin Film Nano-Materials, M Nur-E-Alam, Mikhail Vasiliev, Kamal Alameh, Craig Valli

International Cyber Resilience conference

We develop and characterise new high-performance nano-engineered magneto-optic materials for use in laser-microscopy- based magnetic field visualisers featuring high sensitivity and resolution, low cost and small size. This type of visualisers will make it possible for forensic experts to recover erased data previously stored in high- and ultrahigh-density magnetic disks and hard disk drives.

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 …

A Novel Nonlithographic Method To Fabricate Nanoparticles And Its Application In Crystallization Of Amorphous Silicon Thin Films, Wen Shen

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years nanoparticles fabricated by nonlithographic techniques have shown a very promising alternative implementation to make novel electronic and photonic devices. However, the size control of these nanoparticles has been a great challenge. In this dissertation we used a custom designed ultrahigh vacuum nanocluster deposition system to investigate the size control of nanoparticles by varying different process parameters. The experimental values are compared with existing models and results are found to be in good agreement.

Silicon thin films are very important for the fabrication of a variety of devices including flat panel displays and solar cells. However, the Si …

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

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 …

Theory Of ‘Selectivity’ Of Label-Free Nanobiosensors – A Geometro-Physical Perspective, Pradeep R. Nair, Muhammad A. Alam

Birck and NCN Publications

Modern label-free biosensors are generally far more sensitive and require orders of magnitude less incubation time compared to their classical counterparts. However, a more important characteristic regarding the viability of this technology for applications in Genomics/Proteomics is defined by the ‘Selectivity’, i.e., the ability to concurrently and uniquely detect multiple target biomolecules in the presence of interfering species. Currently, there is no theory of Selectivity that allows optimization of competing factors and there are few experiments to probe this problem systematically. In this article, we use the elementary considerations of surface exclusion, diffusion limited transport, and void distribution function to …

Technological Challenges Of 1-Dimensional Magnetic Photonic Crystals, Mikhail Vasiliev, Kamal Alameh, Dmitry E. Balabanov, Vladimir I. Burkov, V. V. Koledov, Viacheslav A. Kotov, V. G. Shavrov, Anotoly K. Zvezdin

Research outputs pre 2011

Visible-region magnetic photonic crystals (MPC) designed for higher-order bandgap operation have been proposed to overcome the technological restrictions originating from the strong thickness dependency of the individual magnetic layer properties observed in MPC structures.

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

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

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 …

Surface Pre-Treatments And Fabrication Of Highly Ordered Anodic Aluminum Oxide Nanopores At Room Temperature, Sampath Chennuri

Electrical & Computer Engineering Theses & Dissertations

The object of this work is to develop a novel approach to fabricate model membranes of well-defined and well aligned nanostructured materials in a robust environment. The main focus is on electrochemical synthesis, involving anodic oxidation of high purity aluminum sheets to form porous oxide films. Alumina films were prepared by anodizing highly pure aluminum (99.999%) in acidic electrolytes. Anodization parameters (current density, temperature, applied voltage, anodization time and electrolyte concentration) were selected with respect to the electrolyte used.

The primary challenge in nanotechnology is the creation of nanometer-scaled objects with as narrow a size distribution as possible for a …

An Ultrahigh Vacuum Complementary Metal Oxide Silicon Compatible Nonlithographic System To Fabricate Nanoparticle-Based Devices, Arghya Banerjee, Biswajit Das

Electrical & Computer Engineering Faculty Research

Nanoparticles of metals and semiconductors are promising for the implementation of a variety of photonic and electronic devices with superior performances and new functionalities. However, their successful implementation has been limited due to the lack of appropriate fabrication processes that are suitable for volume manufacturing. The current techniques for the fabrication of nanoparticles either are solution based, thus requiring complex surface passivation, or have severe constraints over the choice of particle size and material. We have developed an ultrahigh vacuum system for the implementation of a complex nanosystem that is flexible and compatible with the silicon integrated circuit process, thus …

High-Throughput Screening Of Shape Memory Alloy Thin-Film Spreads Using Nanoindentation, Arpit Dwivedi, Thomas J. Wyrobek, Oden L. Warren, Jason R. Hattrick-Simpers, Olubenga O. Famodu, Ichiro Takeuchi

Faculty Publications

We have demonstrated the utility of nanoindentation as a rapid characterization tool for mapping shape memoryalloy compositions in combinatorial thin-film libraries. Nanoindentation was performed on Ni–Mn–Al ternary composition spreads. The indentation hardness and the reduced elastic modulus were mapped across a large fraction of the ternary phase diagram. The large shape memoryalloy composition region, located around the Heusler composition (Ni₂MnAl), was found to display significant departure in these mechanical properties from the rest of the composition spread. In particular, the modulus and the hardness values are lower for the martensite region than those of the rest of the …

Nanostructured Engineered Materials With High Magneto-Optic Performance For Integrated Photonics Applications, Mikhail Vasiliev, Kamal Alameh, Viacheslav Kotov, Yong-Tak Lee

ECU Presentations

No abstract provided.

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …

Modeling Nerve Electro-Stimulation In The Nanosecond Regime, Feng Chen

Electrical & Computer Engineering Theses & Dissertations

Numerical simulations of electrical stimulation of frog gastrocnemius muscles have been carried out for pulse durations in the nanosecond regime. There are a number of potential advantages in using ultra-short pulses for neural stimulation, and no previous electro-stimulation work in the sub-microsecond regime has been reported. A timedependent, three-dimensional analysis model was developed and implemented for three distinct situations: (i) direct stimulation via electrode contact, (ii) indirect excitation based on electrodes immersed in a saline-filled bath, and (iii) remote electromagnetic stimulation through vacuum. The simulations yielded strength-dm ation (S-D) curves with pulse durations as short as 5 ns. Good agreement …

Investigation Of Nanoporous Thin-Film Alumina Templates, Biswajit Das

Electrical & Computer Engineering Faculty Research

This paper presents the results of a systematic study of the fabrication of thin-film alumina templates on silicon and other substrates. Such templates are of significant interest for the low-cost implementation of semiconductor and metal nanostructure arrays. In addition, thin-film alumina templates on silicon have the potential for nanostructure integration with silicon electronics. Formation of thin-film alumina templates on silicon substrates was investigated under different fabrication conditions, and the dependence of pore morphology and pore formation rate on process parameters was evaluated. In addition, process conditions for improved pore size distribution and periodicity were determined. The template/silicon interface, important for …