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2013

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Articles 1 - 30 of 102

Full-Text Articles in Nanoscience and Nanotechnology

Optical Properties Of Gallium-Doped Zinc Oxide-A Low-Loss Plasmonic Material: First-Principles Theory And Experiment, Jongbum Kim, Gururaj V. Naik, Alexander V. Gavrilenko, Krishnaveni Dondapati, Vladimir I. Gavrilenko, S. M. Prokes, O. J. Glembocki, V. M. Shalaev, Alexandra Boltasseva Dec 2013

Optical Properties Of Gallium-Doped Zinc Oxide-A Low-Loss Plasmonic Material: First-Principles Theory And Experiment, Jongbum Kim, Gururaj V. Naik, Alexander V. Gavrilenko, Krishnaveni Dondapati, Vladimir I. Gavrilenko, S. M. Prokes, O. J. Glembocki, V. M. Shalaev, Alexandra Boltasseva

Birck and NCN Publications

Searching for better materials for plasmonic and metamaterial applications is an inverse design problem where theoretical studies are necessary. Using basic models of impurity doping in semiconductors, transparent conducting oxides (TCOs) are identified as low-loss plasmonic materials in the near-infrared wavelength range. A more sophisticated theoretical study would help not only to improve the properties of TCOs but also to design further lower-loss materials. In this study, optical functions of one such TCO, gallium-doped zinc oxide (GZO), are studied both experimentally and by first-principles density-functional calculations. Pulsed-laser-deposited GZO films are studied by the x-ray diffraction and generalized spectroscopic ellipsometry. Theoretical ...


Spatial Spectrograms Of Vibrating Atomic Force Microscopy Cantilevers Coupled To Sample Surfaces, Ryan Wagner, Arvind Raman, Roger Proksch Dec 2013

Spatial Spectrograms Of Vibrating Atomic Force Microscopy Cantilevers Coupled To Sample Surfaces, Ryan Wagner, Arvind Raman, Roger Proksch

Birck and NCN Publications

Many advanced dynamic Atomic Force Microscopy (AFM) techniques such as contact resonance, force modulation, piezoresponse force microscopy, electrochemical strain microscopy, and AFM infrared spectroscopy exploit the dynamic response of a cantilever in contact with a sample to extract local material properties. Achieving quantitative results in these techniques usually requires the assumption of a certain shape of cantilever vibration. We present a technique that allows in-situ measurements of the vibrational shape of AFM cantilevers coupled to surfaces. This technique opens up unique approaches to nanoscale material property mapping, which are not possible with single point measurements alone. (C) 2013 AIP Publishing ...


The Role Of Oxygen In The Uptake Of Deuterium In Lithiated Graphite, C. N. Taylor, J. Dadras, Kara E. Luitjohan, Jean P. Allain, P. S. Kristic, C. H. Skinner Dec 2013

The Role Of Oxygen In The Uptake Of Deuterium In Lithiated Graphite, C. N. Taylor, J. Dadras, Kara E. Luitjohan, Jean P. Allain, P. S. Kristic, C. H. Skinner

Birck and NCN Publications

We investigate the mechanism of deuterium retention by lithiated graphite and its relationship to the oxygen concentration through surface sensitive experiments and atomistic simulations. Deposition of lithium on graphite yielded 5%-8% oxygen surface concentration and when subsequently irradiated with D ions at energies between 500 and 1000 eV/amu and fluences over 10(16) cm(-2) the oxygen concentration rose to between 25% and 40%. These enhanced oxygen levels were reached in a few seconds compared to about 300 h when the lithiated graphite was allowed to adsorb oxygen from the ambient environment under equilibrium conditions. Irradiating graphite without ...


Limit For Thermal Transport Reduction In Si Nanowires With Nanoengineered Corrugations, Sean E. Sullivan, Keng-Hua Lin, Stanislav Avdoshenko, Alejandro Strachan Dec 2013

Limit For Thermal Transport Reduction In Si Nanowires With Nanoengineered Corrugations, Sean E. Sullivan, Keng-Hua Lin, Stanislav Avdoshenko, Alejandro Strachan

Birck and NCN Publications

Non-equilibrium molecular dynamics simulations reveal that the thermal conductance of Si nanowires with periodic corrugations is lower than that of smooth wires with cross-sections equivalent to the constricted portions. This reduction in conductance is up to 30% and tends to plateau with increasing corrugation height. Spatially resolved temperature and heat current maps provide a microscopic understanding of this effect; we find that 80% of the heat current is carried through the constricted area even for high-amplitude corrugations. More importantly, we show that temperature gradient inversion and heat current vortices at the ridge peaks establish fundamental limits on maximum conductance reduction ...


Bubble And Pattern Formation In Liquid Induced By An Electron Beam, Joseph M. Grogan, Nicholas M. Schneider, Frances M. Ross, Haim H. Bau Dec 2013

Bubble And Pattern Formation In Liquid Induced By An Electron Beam, Joseph M. Grogan, Nicholas M. Schneider, Frances M. Ross, Haim H. Bau

Departmental Papers (MEAM)

Liquid cell electron microscopy has emerged as a powerful technique for in situ studies of nanoscale processes in liquids. An accurate understanding of the interactions between the electron beam and the liquid medium is essential to account for, suppress, and exploit beam effects. We quantify the interactions of high energy electrons with water, finding that radiolysis plays an important role, while heating is typically insignificant. For typical imaging conditions, we find that radiolysis products such as hydrogen and hydrated electrons achieve equilibrium concentrations within seconds. At sufficiently high dose-rate, the gaseous products form bubbles. We image bubble nucleation, growth, and ...


Homogeneous Algan/Gan Superlattices Grown On Free-Standing (1(1)Over-Bar00) Gan Substrates By Plasma-Assisted Molecular Beam Epitaxy, Jiayi Shao, Dmitri N. Zakharov, Collin Edmunds, Oana Malis, Michael J. Manfra Dec 2013

Homogeneous Algan/Gan Superlattices Grown On Free-Standing (1(1)Over-Bar00) Gan Substrates By Plasma-Assisted Molecular Beam Epitaxy, Jiayi Shao, Dmitri N. Zakharov, Collin Edmunds, Oana Malis, Michael J. Manfra

Birck and NCN Publications

Two-dimensional and homogeneous growth of m-plane AlGaN by plasma-assisted molecular beam epitaxy has been realized on free-standing (1 (1) over bar 00) GaN substrates by implementing high metal-to-nitrogen (III/N) flux ratio. AlN island nucleation, often reported for m-plane AlGaN under nitrogen-rich growth conditions, is suppressed at high III/N flux ratio, highlighting the important role of growth kinetics for adatom incorporation. The homogeneity and microstructure of m-plane AlGaN/GaN superlattices are assessed via a combination of scanning transmission electron microscopy and high resolution transmission electron microscopy (TEM). The predominant defects identified in dark field TEM characterization are short basal ...


An Integrated Multidisciplinary Nanoscience Concentration Certificate Program For Stem Education, Karen S. Martirosyan, Mikhail M. Bouniaev, Malik Rachmanov, Ahmed Touhami, Nazmul Islam, Davood Askari, Tarek Trad, Dmitri Litvinov, Sergey E. Lyshevski Dec 2013

An Integrated Multidisciplinary Nanoscience Concentration Certificate Program For Stem Education, Karen S. Martirosyan, Mikhail M. Bouniaev, Malik Rachmanov, Ahmed Touhami, Nazmul Islam, Davood Askari, Tarek Trad, Dmitri Litvinov, Sergey E. Lyshevski

Physics and Astronomy Faculty Publications and Presentations

Integration of nanoscience and nanotechnology curricula into the College of Science, Mathematics, and Technology (CSMT) at the University of Texas at Brownsville (UTB) is reported. The rationale for the established multidisciplinary Nanoscience Concentration Certificate Program (NCCP) is to: (i) develop nanotechnology-relevant courses within a comprehensive Science, Engineering and Technology curriculum, and, to offer students an opportunity to graduate with a certificate in nanoscience and nanotechnology; (ii) to contribute to students' success in achieving student outcomes across all college's majors, and, improve the breath, depth and quality of science, technology, engineering and mathematics (STEM) graduates' education; (iii) through NCCP, recruit ...


Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw Dec 2013

Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmonactive nanostructures of dye-labeled protein and silver nanoparticles ...


Real-Time Biosensor For The Assessment Of Nanotoxicity And Cancer Electrotherapy, Evangelia Hondroulis Nov 2013

Real-Time Biosensor For The Assessment Of Nanotoxicity And Cancer Electrotherapy, Evangelia Hondroulis

FIU Electronic Theses and Dissertations

Knowledge of cell electronics has led to their integration to medicine either by physically interfacing electronic devices with biological systems or by using electronics for both detection and characterization of biological materials. In this dissertation, an electrical impedance sensor (EIS) was used to measure the electrode surface impedance changes from cell samples of human and environmental toxicity of nanoscale materials in 2D and 3D cell culture models. The impedimetric response of human lung fibroblasts and rainbow trout gill epithelial cells when exposed to various nanomaterials was tested to determine their kinetic effects towards the cells and to demonstrate the biosensor ...


A Simple Add-On Microfluidic Appliance For Accurately Sorting Small Populations Of Cells With High Fidelity, Michael Grad, Erik F. Young, Lubomir Smilenov, David J. Brenner, Daniel Attinger Nov 2013

A Simple Add-On Microfluidic Appliance For Accurately Sorting Small Populations Of Cells With High Fidelity, Michael Grad, Erik F. Young, Lubomir Smilenov, David J. Brenner, Daniel Attinger

Mechanical Engineering Publications

Current advances in single cell sequencing, gene expression and proteomics require the isolation of single cells, frequently from a very small source population. In this work we describe the design and characterization of a manually operated microfluidic cell sorter that (1) can accurately sort single or small groups of cells from very small cell populations with minimal losses, (2) that is easy to operate and that can be used in any laboratory that has a basic fluorescent microscope and syringe pump, (3) that can be assembled within minutes, (4) that can sort cells in very short time (minutes) with minimum ...


Scalar Differential Equation For Slowly-Varying Thickness-Shear Modes In At-Cut Quartz Resonators With Surface Impedance For Acoustic Wave Sensor Application, Huijing He, Jiashi Yang, John A. Kosinski Nov 2013

Scalar Differential Equation For Slowly-Varying Thickness-Shear Modes In At-Cut Quartz Resonators With Surface Impedance For Acoustic Wave Sensor Application, Huijing He, Jiashi Yang, John A. Kosinski

Mechanical & Materials Engineering Faculty Publications

For time-harmonic motions, we generalize a 2-D scalar differential equation derived previously by Tiersten for slowly-varying thickness-shear vibrations of AT-cut quartz resonators. The purpose of the generalization is to include the effects of surface acoustic impedance from, e.g., mass layers or fluids for sensor applications. In addition to the variation of fields along the plate thickness, which is considered in the usual 1-D acoustic wave sensor models, the equation obtained also describes in-plane variations of the fields, and therefore can be used to study the vibrations of finite plate sensors with edge effects. The equation is compared with the ...


A New Angle On Microscopic Suspension Feeders Near Boundaries, Rachel E. Pepper, Marcus Roper, Sangjin Ryu, Nobuyoshi Matsumoto, Moeto Nagai, Howard A. Stone Oct 2013

A New Angle On Microscopic Suspension Feeders Near Boundaries, Rachel E. Pepper, Marcus Roper, Sangjin Ryu, Nobuyoshi Matsumoto, Moeto Nagai, Howard A. Stone

Mechanical & Materials Engineering Faculty Publications

Microscopic sessile suspension feeders are a critical component in aquatic ecosystems, acting as an intermediate trophic stage between bacteria and higher eukaryotic taxa. Because they live attached to boundaries, it has long been thought that recirculation of the feeding currents produced by sessile suspension feeders inhibits their ability to access fresh fluid. However, previous models for the feeding flows of these organisms assume that they feed by pushing fluid perpendicular to surfaces they live upon, whereas we observe that sessile suspension feeders often feed at an angle to these boundaries. Using experiments and calculations, we show that living suspension feeders ...


Near Sputter-Threshold Gasb Nanopatterning, Osman El-Atwani, Sean Gonderman, Jean Paul Allain Sep 2013

Near Sputter-Threshold Gasb Nanopatterning, Osman El-Atwani, Sean Gonderman, Jean Paul Allain

Birck and NCN Publications

Nanopatterning at sputter-threshold energies with Ar irradiation of GaSb (100) surfaces is presented. Comparison with high-energy irradiations up to 1000 eV is conducted measuring in-situ the composition evolution over irradiation time at early stages (e. g., < 10(17) cm(-2)) and up to nanostructure saturation (e. g., similar to 10(18) cm(-2)). Low-energy irradiation is conducted for energies between 15-100 eV and a low-aspect ratio nanostructured dot formation is found. Furthermore, the role of oxide on GaSb is found to delay nanostructure formation and this is predominant at energies below 100 eV. In-situ quartz crystal microbalance measurements collect sputtered particles yielding the sputter rate at threshold energies indicating a correlation between erosion and surface composition consistent with recent theoretical models. Ion-induced segregation is also found and indicated by both compositional measurements of both the surface and the sputtered plume. (C) 2013 AIP Publishing LLC.


Giant Quasiparticle Bandgap Modulation In Graphene Nanoribbons Supported On Weakly Interacting Surfaces, Xueping Jiang, Neerav Kharche, Paul Kohl, Timothy B. Boykin, Gerhard Klimeck, Mathieu Luisier, Pulickel M. Ajayan, Saroj K. Nayak Sep 2013

Giant Quasiparticle Bandgap Modulation In Graphene Nanoribbons Supported On Weakly Interacting Surfaces, Xueping Jiang, Neerav Kharche, Paul Kohl, Timothy B. Boykin, Gerhard Klimeck, Mathieu Luisier, Pulickel M. Ajayan, Saroj K. Nayak

Birck and NCN Publications

In general, there are two major factors affecting bandgaps in nanostructures: (i) the enhanced electron-electron interactions due to confinement and (ii) the modified selfenergy of electrons due to the dielectric screening. While recent theoretical studies on graphene nanoribbons (GNRs) report on the first effect, the effect of dielectric screening from the surrounding materials such as substrates has not been thoroughly investigated. Using large-scale electronic structure calculations based on the GW approach, we show that when GNRs are deposited on substrates, bandgaps get strongly suppressed (by as much as 1 eV) even though the GNR-substrate interaction is weak.


Quantum Hall Effect In Monolayer-Bilayer Graphene Planar Junctions, Jifa Tian, Yongjin Jiang, Isaac Childres, Helin Cao, Jiangping Hu, Yong P. Chen Sep 2013

Quantum Hall Effect In Monolayer-Bilayer Graphene Planar Junctions, Jifa Tian, Yongjin Jiang, Isaac Childres, Helin Cao, Jiangping Hu, Yong P. Chen

Birck and NCN Publications

The Hall resistance of a homogeneous electron system is well known to be antisymmetric with respect to the magnetic field and the sign of charge carriers. We have observed that such symmetries no longer hold in planar hybrid structures consisting of partly single layer graphene (SLG) and partly bilayer graphene (BLG) in the quantum Hall (QH) regime. In particular, the Hall resistance across the SLG and BLG interface is observed to exhibit quantized plateaus that switch between those characteristic of SLG QH states and BLG QH states when either the sign of the charge carriers (controlled by a back gate ...


Metal-Assisted Etching Of Silicon Molds For Electroforming, Ralu Divan, Dan Rosenthal '14, Karim Ogando, Leonidas E. Ocola, Daniel Rosenmann, Nicolaie Moldovan Sep 2013

Metal-Assisted Etching Of Silicon Molds For Electroforming, Ralu Divan, Dan Rosenthal '14, Karim Ogando, Leonidas E. Ocola, Daniel Rosenmann, Nicolaie Moldovan

Student Publications & Research

Ordered arrays of high-aspect-ratio micro/nanostructures in semiconductors stirred a huge scientific interest due to their unique one-dimensional physical morphology and the associated electrical, mechanical, chemical, optoelectronic, and thermal properties. Metal-assisted chemical etching enables fabrication of such high aspect ratio Si nanostructures with controlled diameter, shape, length, and packing density, but suffers from structure deformation and shape inconsistency due to uncontrolled migration of noble metal structures during etching. Hereby the authors prove that a Ti adhesion layer helps in stabilizing gold structures, preventing their migration on the wafer surface while not impeding the etching. Based on this finding, the authors ...


Effects Of Nanocrystal Shape And Size On The Temperature Sensitivity In Raman Thermometry, Liangliang Chen, Kelly Rickey, Qing Zhao, Christopher Robinson, Xiulin Ruan Aug 2013

Effects Of Nanocrystal Shape And Size On The Temperature Sensitivity In Raman Thermometry, Liangliang Chen, Kelly Rickey, Qing Zhao, Christopher Robinson, Xiulin Ruan

Birck and NCN Publications

The effects of CdSe nanocrystal (NC) shape and size on the temperature sensitivity of the Raman shift have been investigated, for the interest of Raman thermometry using NCs. For spherical CdSe NCs of diameters 2.8 nm, 3.6 nm, and 4.4 nm, the temperature sensitivities are -0.0131 cm(-1)/K, -0.0171 cm(-1)/K, and -0.0242 cm(-1)/K, respectively. This trend indicates that as the diameter increases, the effect of increasing phonon anharmonicity dominates over the effect of the decreasing thermal expansion coefficient. On the other hand, triangular NCs with a size of 4 ...


Electronic And Optical Properties Of Scn And (Sc,Mn)N Thin Films Deposited By Reactive Dc-Magnetron Sputtering, Bivas Saha, Gururaj V. Naik, Vladimir P. Drachev, Alexandra Boltasseva, Ernesto Marinero, Timothy D. Sands Aug 2013

Electronic And Optical Properties Of Scn And (Sc,Mn)N Thin Films Deposited By Reactive Dc-Magnetron Sputtering, Bivas Saha, Gururaj V. Naik, Vladimir P. Drachev, Alexandra Boltasseva, Ernesto Marinero, Timothy D. Sands

Birck and NCN Publications

Scandium nitride (ScN) is a rocksalt semiconductor that has attracted significant attention from various researchers for a diverse range of applications. Motivated by the prospect of using its interesting electronic structure for optoelectronic and dilute magnetic semiconductor applications, we present detailed studies of the electronic transport and optical properties of ScN and its alloys with manganese nitride (MnN). Our results suggest (a) dilute manganese doping in ScN compensates for the high n-type carrier concentrations arising due to oxygen impurities and (b) an n-type to p-type carrier type transition occurs at a composition between 5.8% and 11% Mn on Sc ...


Frequency Response Of Atmospheric Pressure Gas Breakdown In Micro/Nanogaps, Abbas Semnani, Ayyaswamy Venkattraman, Alina A. Alexeenko, Dimitrios Peroulis Aug 2013

Frequency Response Of Atmospheric Pressure Gas Breakdown In Micro/Nanogaps, Abbas Semnani, Ayyaswamy Venkattraman, Alina A. Alexeenko, Dimitrios Peroulis

Birck and NCN Publications

In this paper, we study gas breakdown in micro/nanogaps at atmospheric pressure from low RF to high millimeter band. For gaps larger than about 10 mu m, the breakdown voltage agrees with macroscale vacuum experiments, exhibiting a sharp decrease at a critical frequency, due to transition between the boundary- and diffusion-controlled regimes, and a gradual increase at very high frequencies as a result of inefficient energy transfer by field. For sub-micron gaps, a much lower breakdown is obtained almost independent of frequency because of the dominance of field emission. (C) 2013 AIP Publishing LLC.


A Humidity-Sensitive Hydrogel-Bacillus Spore Composite For Micropatterning Of Biomolecular Gradients, Richard L. Gieseck, Bin-Da Chan, Cagri A. Savran Aug 2013

A Humidity-Sensitive Hydrogel-Bacillus Spore Composite For Micropatterning Of Biomolecular Gradients, Richard L. Gieseck, Bin-Da Chan, Cagri A. Savran

Birck and NCN Publications

A composite material consisting of Bacillus subtilis spores suspended in a humidity sensitive hydrogel can be used to pattern biomolecules in different concentrations directly onto glass surfaces using a mechanical micromanipulator. By altering the relative humidity surrounding the composite gel during deposition, surface concentration of patterned biomolecules can be controlled and varied to create user-defined, biomolecular surface concentrations. (C) 2013 AIP Publishing LLC.


Mapping The 3d Surface Potential In Bi2se3, Chris Mann, Damien West, Ireneusz Miotkowski, Yong P. Chen, Shengbai Zhang, Chih-Kang Shih Aug 2013

Mapping The 3d Surface Potential In Bi2se3, Chris Mann, Damien West, Ireneusz Miotkowski, Yong P. Chen, Shengbai Zhang, Chih-Kang Shih

Birck and NCN Publications

Bi2Se3 initially emerged as a particularly promising host of topological physics. However, in actual materials, several issues have been uncovered including strong surface band bending and potential fluctuations. To investigate these concerns, we study nominally stoichiometric Bi2Se3 using scanning tunnelling microscopy. Here we identify two distinct distributions of Bi-Se antisites that act as nanometer-scale sensors for the surface band-bending field. To confirm this, we examine bulk Cu-doped Bi2Se3 and demonstrate a significantly reduced surface band-bending field. In addition, we find that in the case of unintentionally doped Bi2Se3, lateral fluctuations of the Dirac point can be directly correlated with specific ...


Pan Nanofibers And Nanofiber Reinforced Composites, Cheng Ren Aug 2013

Pan Nanofibers And Nanofiber Reinforced Composites, Cheng Ren

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Nanomaterials play an important role in the development of nanotechnology. They possess unique mechanical, physical, and chemical properties coupled with small size and ultrahigh surface area that can provide critical advantages for applications. Continuous nanofibers attract special interest due to their dual nano-macro nature and ability to bridge scales. Nanofibers are being considered for a broad range of applications spanning advanced filters, separation membranes, ultrasensitive sensors, micro/nano actuators, nanoprobes, tissue engineering scaffolds, protective and smart closing, and multifunctional composites. Most of these applications require certain mechanical properties and robustness. However, the literature on the mechanical behavior of nanofibers and ...


Site Specifc Growth Of Metal Catalyzed Silica Nanowires For Biological And Chemical Sensing, Eric G. Huey Jul 2013

Site Specifc Growth Of Metal Catalyzed Silica Nanowires For Biological And Chemical Sensing, Eric G. Huey

FIU Electronic Theses and Dissertations

In this research the integration of nanostructures and micro-scale devices was investigated using silica nanowires to develop a simple yet robust nanomanufacturing technique for improving the detection parameters of chemical and biological sensors. This has been achieved with the use of a dielectric barrier layer, to restrict nanowire growth to site-specific locations which has removed the need for post growth processing, by making it possible to place nanostructures on pre-pattern substrates. Nanowires were synthesized using the Vapor-Liquid-Solid growth method. Process parameters (temperature and time) and manufacturing aspects (structural integrity and biocompatibility) were investigated.

Silica nanowires were observed experimentally to determine ...


Hysteretic Response Of Chemical Vapor Deposition Graphene Field Effect Transistors On Sic Substrates, Edward Cazalas, Isaac Childres, Amanda Majcher, Ting Fung Chung, Yong P. Chen, Igor Jovanovic Jul 2013

Hysteretic Response Of Chemical Vapor Deposition Graphene Field Effect Transistors On Sic Substrates, Edward Cazalas, Isaac Childres, Amanda Majcher, Ting Fung Chung, Yong P. Chen, Igor Jovanovic

Birck and NCN Publications

Graphene field effect transistors (GFETs) fabricated by chemical vapor deposition graphene deposited onto SiC substrates exhibit sensitivity to broadband visible light. The hysteretic nature of this GFET type was studied utilizing a new current-voltage measurement technique in conjunction with current-time measurements. This measurement method accounts for hysteretic changes in graphene response and enables transfer measurements that can be attributed to fixed gate voltages. Graphene hysteresis is shown to be consistent with electrochemical p-type doping, and current-time measurements clearly resolve a hole to electron to hole carrier transition in graphene with a single large change in gate voltage. (C) 2013 AIP ...


Surface Morphology Evolution Of M-Plane (1(1)Over-Bar00) Gan During Molecular Beam Epitaxy Growth: Impact Of Ga/N Ratio, Miscut Direction, And Growth Temperature, Jiayi Shao, Liang Tang, Colin Edmunds, Geoff C. Gardner, Oana Malis, Michael J. Manfra Jul 2013

Surface Morphology Evolution Of M-Plane (1(1)Over-Bar00) Gan During Molecular Beam Epitaxy Growth: Impact Of Ga/N Ratio, Miscut Direction, And Growth Temperature, Jiayi Shao, Liang Tang, Colin Edmunds, Geoff C. Gardner, Oana Malis, Michael J. Manfra

Birck and NCN Publications

We present a systematic study of morphology evolution of [1 (1) over bar 00] m-plane GaN grown by plasma-assisted molecular beam epitaxy on free-standing m-plane substrates with small miscut angles towards the -c [000 (1) over bar] and +c [0001] directions under various gallium to nitrogen (Ga/N) ratios at substrate temperatures T = 720 degrees C and T = 740 degrees C. The miscut direction, Ga/N ratio, and growth temperature are all shown to have a dramatic impact on morphology. The observed dependence on miscut direction supports the notion of strong anisotropy in the gallium adatom diffusion barrier and growth ...


Book Review: Nanoelectric Devices By Byung-Gook Park, Sung Woo Huang And Young June Park, Ganesh Balasubramanian Jul 2013

Book Review: Nanoelectric Devices By Byung-Gook Park, Sung Woo Huang And Young June Park, Ganesh Balasubramanian

Mechanical Engineering Publications

The importance of nanoelectronics is enormous given the constant demand for enhancement in performance of electronic and computing devices. While Moore's law predicted the exponential increase in the power of processing units, the associated device level physics have brought about a new set of interdisciplinary challenges. Miniaturization of transistors has been the key to the unprecedented growth of microelectronics and its gradual transition to lower length scales. However, system sizes at the nanoscale being comparable to the mean free paths of the charge carriers (electrons), additional considerations in the transport processes need to be accounted for to obtain a ...


Silicon Quantum Electronics, Floris A. Zwanenburg, Andrew S. Dzurak, Andrea Morello, Michelle Y. Simmons, Lloyd C. L. Hollenberg, Gerhard Klimeck, Sven Rogge, Susan N. Coppersmith, Mark A. Eriksson Jul 2013

Silicon Quantum Electronics, Floris A. Zwanenburg, Andrew S. Dzurak, Andrea Morello, Michelle Y. Simmons, Lloyd C. L. Hollenberg, Gerhard Klimeck, Sven Rogge, Susan N. Coppersmith, Mark A. Eriksson

Birck and NCN Publications

This review describes recent groundbreaking results in Si, Si/SiGe, and dopant-based quantum dots, and it highlights the remarkable advances in Si-based quantum physics that have occurred in the past few years. This progress has been possible thanks to materials development of Si quantum devices, and the physical understanding of quantum effects in silicon. Recent critical steps include the isolation of single electrons, the observation of spin blockade, and single-shot readout of individual electron spins in both dopants and gated quantum dots in Si. Each of these results has come with physics that was not anticipated from previous work in ...


Quest For Organic Plasmonics, Lei Gu, J. Livenere, G. Zhu, Evgenii E. Narimanov, M. A. Noginov Jul 2013

Quest For Organic Plasmonics, Lei Gu, J. Livenere, G. Zhu, Evgenii E. Narimanov, M. A. Noginov

Birck and NCN Publications

Many photonic metamaterials and plasmonic devices, in spite of their unparalleled responses to light waves and nearly fantastic applications, suffer from absorption loss in constituent metallic components. Unfortunately, none of the known techniques aimed to conquer the absorption loss has led to a revolutionary technological breakthrough, prompting a continuing quest for efficient solutions to the loss problem. In this letter, we study optical properties of non-metallic organic plasmonic and epsilon-near-zero materials and demonstrate propagation of a surface plasmon polariton at the interface between solid organic dye and air. (C) 2013 AIP Publishing LLC.


High Precision Dynamic Alignment And Gap Control For Optical Near-Field Nanolithography, Xiaolei Wen, Luis M. Traverso, Pornsak Srisungsitthisunti, Xianfan Xu, Euclid E. Moon Jul 2013

High Precision Dynamic Alignment And Gap Control For Optical Near-Field Nanolithography, Xiaolei Wen, Luis M. Traverso, Pornsak Srisungsitthisunti, Xianfan Xu, Euclid E. Moon

Birck and NCN Publications

The authors demonstrate the use of interferometric-spatial-phase-imaging (ISPI) to control a gap distance of the order of nanometers for parallel optical near-field nanolithography. In optical near-field nanolithography, the distance between the optical mask and the substrate needs to be controlled within tens of nanometers or less. The ISPI technique creates interference fringes from checkerboard gratings fabricated on the optical mask, which are used to determine the gap distance between the mask and the substrate surfaces. The sensitive of this gapping technique can reach 0.15 nm. With the use of ISPI and a dynamic feedback control system, the authors can ...


Preparation And Characterization Of Whey Protein Isolate Films Reinforced With Porous Silica Coated Titania Nanoparticles, Dattatreya M. Kadam, Mahendra Thunga, Sheng Wang, Michael R. Kessler, David A. Grewell, Buddhi P. Lamsal, Chenxu Yu Jul 2013

Preparation And Characterization Of Whey Protein Isolate Films Reinforced With Porous Silica Coated Titania Nanoparticles, Dattatreya M. Kadam, Mahendra Thunga, Sheng Wang, Michael R. Kessler, David A. Grewell, Buddhi P. Lamsal, Chenxu Yu

Agricultural and Biosystems Engineering Publications

Whey protein isolate (WPI) films embedded with TiO2@@SiO2 (porous silica (SiO2) coated titania (TiO2)) nanoparticles for improved mechanical properties were prepared by solution casting. A WPI solution of 1.5 wt% TiO2@@SiO2 nanoparticles was subjected to sonication at amplitudes of 0, 16, 80 and 160 μm prior to casting in order to improve the film forming properties of protein and to obtain a uniform distribution of nanoparticles in the WPI films. The physical and mechanical properties of the films were determined by dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and tensile testing. Water vapor permeability (WVP) measurements revealed ...