Sample records for locate graphene islands

  1. Increasing the active surface of titanium islands on graphene by nitrogen sputtering

    E-Print Network [OSTI]

    Mashoff, T; Miseikis, V; Coletti, C; Piazza, V; Beltram, F; Heun, S

    2014-01-01T23:59:59.000Z

    Titanium-island formation on graphene as a function of defect density is investigated. When depositing titanium on pristine graphene, titanium atoms cluster and form islands with an average diameter of about 10nm and an average height of a few atomic layers. We show that if defects are introduced in the graphene by ion bombardment, the mobility of the deposited titanium atoms is reduced and the average diameter of the islands decreases to 5nm with monoatomic height. This results in an optimized coverage for hydrogen storage applications since the actual titanium surface available per unit graphene area is significantly increased.

  2. Exploring the structure and chemical activity of 2-D gold islands on graphene moire/Ru(0001)

    E-Print Network [OSTI]

    Goodman, Wayne

    Exploring the structure and chemical activity of 2-D gold islands on graphene moire/Ru(0001) Ye Xu May 2011 DOI: 10.1039/c1fd00030f Au deposited on Ru(0001)-supported extended, continuous graphene. These Au islands conform to the corrugation of the underlying graphene and display commensurate moire

  3. Highly Anisotropic Dirac Cones in Epitaxial Graphene Modulated by an Island Superlattice S. Rusponi,1

    E-Print Network [OSTI]

    Brune, Harald

    Highly Anisotropic Dirac Cones in Epitaxial Graphene Modulated by an Island Superlattice S. Rusponi affects the spectral-weight distribution of the carbon bands as well as the electronic gaps between generation electronic devices [2]. Freestanding graphene is a zero-gap semiconductor. Because most electronic

  4. Cooperative Island Growth of Large Area Single-Crystal Graphene by Chemical Vapor Deposition on Cu

    SciTech Connect (OSTI)

    Regmi, Murari [Oak Ridge National Laboratory (ORNL); Rouleau, Christopher [Oak Ridge National Laboratory (ORNL); Puretzky, Alexander A [ORNL; Ivanov, Ilia N [ORNL; Geohegan, David B [ORNL; Chen, Jihua [ORNL; Eastman, Jeffrey [Argonne National Laboratory (ANL); Eres, Gyula [ORNL

    2014-01-01T23:59:59.000Z

    We describe a two-step approach for suppressing nucleation of graphene on Cu using chemical vapor deposition. In the first step, as received Cu foils are oxidized in air at temperatures up to 500 C to remove surface impurities and to induce the regrowth of Cu grains during subsequent annealing in H2 flow at 1040 C prior to graphene growth. In the second step, transient reactant cooling is performed by using a brief Ar pulse at the onset of growth to induce collisional deactivation of the carbon growth species. The combination of these two steps results in a three orders of magnitude reduction in the graphene nucleation density, enabling the growth of millimeter-size single crystal graphene grains. A kinetic model shows that suppressing nucleation promotes a cooperative island growth mode that favors the formation of large area single crystal graphene, and it is accompanied by a roughly 3 orders of magnitude increase in the reactive sticking probability of methane compared to that in random nucleation growth.

  5. NAME: Molokai Fish Pond & Fringing Reef Restoration LOCATION: Kaunakakai, Island of Molokai (Maui County), Hawai'i

    E-Print Network [OSTI]

    US Army Corps of Engineers

    NAME: Molokai Fish Pond & Fringing Reef Restoration LOCATION: Kaunakakai, Island of Molokai (Maui fish ponds on the fringing reef of the Hawaiian island of Molokai. Mangroves were planted in 1902 conditions and threaten to take over the reef flats and fish ponds. EXPECTED BENEFITS: Fine sediment flushed

  6. A Locational Analysis of Generation Benefits on Long Island, NewYork

    SciTech Connect (OSTI)

    Wang, Juan; Cohen, Jesse; Edwards, Jennifer; Marnay, Chris

    2005-11-08T23:59:59.000Z

    Beginning in April of 2004, nine sites owned by Verizon began to participate in the Long Island Real Time Purchasing Pilot Project (LIRTP) as retail choice customers. LIRTP was designed to minimize electricity costs for retail customers who own on-site distributed generation (DG) units in the near-term, and to stabilize overall electricity costs in the long-term. The nine Verizon buildings have two types of DG units: gas turbines with an estimated generation cost of $156/MWh, and diesel units with an estimated cost of $120/MWh. Due to total site emission limits, the operable hours of the DG units are limited. To estimate the economic value of running on-site DG units, an analysis of the New York Independent System Operator (NYISO) Locational Based Marginal Price (LBMP) data for Long Island was conducted, mainly covering the summer months from 2000 to 2004. Distributions of LBMP, relationship between LBMP and load, and estimates of profitable operating hours for the units were all analyzed. Since Long Island is a diverse and highly congested area, LBMP varies greatly. Looking at the data statistically offers a zone-wide viewpoint, while using spatial analysis shows the LBMP intrazonal differentiation. LBMP is currently used by NYISO for pricing in the 11 NY control zones. Because geographic information systems (GIS) visualize the distribution of a phenomenon over space, it clarifies where load and generation nodes are located, and where load reduction would be most valuable. This study is based on the assumption that the control zone areas do not fully represent the diversity of pricing, and that intrazonal pricing can be analyzed to determine where and when electricity conservation or injection into the network is most valuable.

  7. ISLANDER

    Energy Science and Technology Software Center (OSTI)

    003251WKSTN00 Genomic Island Identification Software v 1.0  http://bioinformatics.sandia.gov/software 

  8. Graphene and Graphene Oxide: Biofunctionalization and Applications...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Graphene Oxide: Biofunctionalization and Applications in Biotechnology. Graphene and Graphene Oxide: Biofunctionalization and Applications in Biotechnology. Abstract: Graphene...

  9. Graphene Transistors Fabricated via Transfer-Printing In Device Active-Areas

    E-Print Network [OSTI]

    Graphene Transistors Fabricated via Transfer-Printing In Device Active-Areas on Large Wafer Xiaogan graphene islands from a graphite and then uses transfer printing to place the islands from the stamp from the printed graphene. The transistors show a hole and electron mobility of 3735 and 795 cm2/V

  10. Thermal Conduction in Graphene and Graphene Multilayers

    E-Print Network [OSTI]

    Ghosh, Suchismita

    2009-01-01T23:59:59.000Z

    graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .graphene . . . . . . . . . . . . . . . . . . . . . . . . .image of a typical single-layer graphene (SLG) on Si/SiO 2

  11. Rules Establishing Minimum Standards Relating to Location, Design, Construction, and Maintenance of Onsite Wastewater Treatment Systems (Rhode Island)

    Broader source: Energy.gov [DOE]

    The purpose of these rules is to protect public health and the environment by establishing minimum standards for the proper location, design, construction and maintenance of onsite wastewater...

  12. Deposition of thin silicon layers on transferred large area graphene

    SciTech Connect (OSTI)

    Lupina, Grzegorz, E-mail: lupina@ihp-microelectronics.com; Kitzmann, Julia; Lukosius, Mindaugas; Dabrowski, Jarek; Wolff, Andre; Mehr, Wolfgang [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany)] [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany)

    2013-12-23T23:59:59.000Z

    Physical vapor deposition of Si onto transferred graphene is investigated. At elevated temperatures, Si nucleates preferably on wrinkles and multilayer graphene islands. In some cases, however, Si can be quasi-selectively grown only on the monolayer graphene regions while the multilayer islands remain uncovered. Experimental insights and ab initio calculations show that variations in the removal efficiency of carbon residuals after the transfer process can be responsible for this behavior. Low-temperature Si seed layer results in improved wetting and enables homogeneous growth. This is an important step towards realization of electronic devices in which graphene is embedded between two Si layers.

  13. Noncommutative Graphene

    E-Print Network [OSTI]

    C. Bastos; O. Bertolami; N. Dias; J. Prata

    2012-07-24T23:59:59.000Z

    We consider a noncommutative description of graphene. This description consists of a Dirac equation for massless Dirac fermions plus noncommutative corrections, which are treated in the presence of an external magnetic field. We argue that, being a two-dimensional Dirac system, graphene is particularly interesting to test noncommutativity. We find that momentum noncommutativity affects the energy levels of graphene, but that it does not entail any kind of correction to the Hall conductivity.

  14. Arctic ice islands

    SciTech Connect (OSTI)

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.C.

    1988-01-01T23:59:59.000Z

    The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.

  15. Raman Nanometrology of Graphene

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01T23:59:59.000Z

    13 Optical image of the graphene layers. . . . . .Micro-Raman Spectroscopy of Grapheneand Graphene Multi-Layers . . . . Raman Spectroscopy

  16. Characterization of few-layered graphene grown by carbon implantation

    SciTech Connect (OSTI)

    Lee, Kin Kiong; McCallum, Jeffrey C.; Jamieson, David N. [Centre for Quantum Computation and Communication Technology, School of Physics, The University of Melbourne, Parkville, Victoria 3010 (Australia)

    2014-02-21T23:59:59.000Z

    Graphene is considered to be a very promising material for applications in nanotechnology. The properties of graphene are strongly dependent on defects that occur during growth and processing. These defects can be either detrimental or beneficial to device performance depending on defect type, location and device application. Here we present experimental results on formation of few-layered graphene by carbon ion implantation into nickel films and characteristics of graphene devices formed by graphene transfer and lithographic patterning. Micro-Raman spectroscopy was used to determine the number of graphene layers formed and identify defects arising from the device processing. The graphene films were cleaned by annealing in vacuum. Transport properties of cleaned graphene films were investigated by fabrication of back-gated field-effect transistors, which exhibited high hole and electron mobility of 1935 and 1905 cm2/Vs, respectively.

  17. Negative compressibility observed in graphene containing resonant impurities

    SciTech Connect (OSTI)

    Chen, X. L.; Wang, L.; Li, W.; Wang, Y.; He, Y. H.; Wu, Z. F.; Han, Y.; Zhang, M. W.; Xiong, W.; Wang, N. [Department of Physics and The William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)] [Department of Physics and The William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

    2013-05-20T23:59:59.000Z

    We observed negative compressibility in monolayer graphene containing resonant impurities under different magnetic fields. Hydrogenous impurities were introduced into graphene by electron beam (e-beam) irradiation. Resonant states located in the energy region of {+-}0.04 eV around the charge neutrality point were probed in e-beam-irradiated graphene capacitors. Theoretical results based on tight-binding and Lifshitz models agreed well with experimental observations of graphene containing a low concentration of resonant impurities. The interaction between resonant states and Landau levels was detected by varying the applied magnetic field. The interaction mechanisms and enhancement of the negative compressibility in disordered graphene are discussed.

  18. Introduction Transport in disordered graphene

    E-Print Network [OSTI]

    Fominov, Yakov

    Introduction Transport in disordered graphene Summary Ballistic transport in disordered graphene P, Gornyi, Mirlin Ballistic transport in disordered graphene #12;Introduction Transport in disordered graphene Summary Outline 1 Introduction Model Experimental motivation Transport in clean graphene 2

  19. Atomic and electronic structure of monolayer graphene on 6H-SiC(0001)(3 3) : a scanning tunneling microscopy study.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Atomic and electronic structure of monolayer graphene on 6H-SiC(0001)(3 × 3) : a scanning tunneling of the atomic and electronic structure of graphene monolayer islands on the 6H-SiC(0001)(3×3) (SiC(3×3)) surface reconstruction using scanning tunneling microscopy (STM) and spectroscopy (STS). The orientation of the graphene

  20. Controlling Graphene's Electronic Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Controlling Graphene's Electronic Structure Print Wednesday, 25 April 2007 00:00 Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has...

  1. Hydrogen storage with titanium-functionalized graphene

    E-Print Network [OSTI]

    Mashoff, Torge; Tanabe, Shinichi; Hibino, Hiroki; Beltram, Fabio; Heun, Stefan

    2013-01-01T23:59:59.000Z

    We report on hydrogen adsorption and desorption on titanium-covered graphene in order to test theoretical proposals to use of graphene functionalized with metal atoms for hydrogen storage. At room temperature titanium islands grow with an average diameter of about 10 nm. Samples were then loaded with hydrogen, and its desorption kinetics was studied by thermal desorption spectroscopy. We observe the desorption of hydrogen in the temperature range between 400K and 700 K. Our results demonstrate the stability of hydrogen binding at room temperature and show that hydrogen desorbs at moderate temperatures in line with what required for practical hydrogen-storage applications.

  2. Effects of nonmagnetic impurities on the spin transport property of a graphene nanoribbon device

    E-Print Network [OSTI]

    Lee, EokKyun

    Effects of nonmagnetic impurities on the spin transport property of a graphene nanoribbon device to an edge of a graphene nanoribbon device GND with zigzag edges. A center-located impurity enables both American Institute of Physics. DOI: 10.1063/1.3138776 I. INTRODUCTION Electronic spin transport in graphene

  3. Energy Blog | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    March 7, 2012 Take advantage of microwave microscopy, researchers were able to locate graphene islands on graphene. "Point defects" locally enhanced the graphene's ability to...

  4. Determining graphene adhesion via substrate-regulated morphology of graphene

    E-Print Network [OSTI]

    Li, Teng

    Determining graphene adhesion via substrate-regulated morphology of graphene Zhao Zhang and Teng Li Institute of Physics. Related Articles Identification of graphene crystallographic orientation by atomic two-dimensional, epitaxially-grown, nanostructured graphene for study of single molecule

  5. Graphene Coating Coupled Emission

    E-Print Network [OSTI]

    Shyamasundar, R.K.

    Graphene Coating Coupled Emission A COMSET, A single sheet of sp2-hybridized carbon atoms, called of graphene and its unique properties, I will present amplification of surface graphene-Ag hybrid films which when graphene is used as the spacer layer in a conventional Ag- harnessed the nonlinear properties

  6. Graphene Growth and Device Integration

    E-Print Network [OSTI]

    : 1) exfoliated graphene from natural graphite or various other sources of graphite [24]; 2) graphene of the graphene sources has its advantages and disadvantages: Graphene exfoliated from natural graphite Manuscript

  7. NEST Scientific Report 2007-2009 Graphene and artificial graphene

    E-Print Network [OSTI]

    Abbondandolo, Alberto

    NEST Scientific Report 2007-2009 Graphene 43 Graphene and artificial graphene T his area-layer graphene behave like massless fermions. Graphene is a first remarkable and clean example of the impact of a potential with honeycomb structure on the electronic states and dynamics. In graphene the crystalline

  8. Electrical and Mechanical Properties of Graphene

    E-Print Network [OSTI]

    Bao, Wenzhong

    2011-01-01T23:59:59.000Z

    another method to exfoliate relative large graphene flakes,graphene devices, we exfoliate graphene sheets on standardfabrication process. We first exfoliate graphene sheets on

  9. Electronic and Spintronic Properties of Graphene

    E-Print Network [OSTI]

    Pi, Keyu

    2010-01-01T23:59:59.000Z

    and Spintronic Properties of Graphene by Ke-yu Pi Doctor ofof transition metal doped graphene over the last six years.steps including our graphene exfoliation, graphene

  10. Carbon impurities on graphene synthesized by chemical vapor deposition on platinum

    SciTech Connect (OSTI)

    Ping, Jinglei; Fuhrer, Michael S., E-mail: michael.fuhrer@monash.edu [Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742-4111, USA and School of Physics, Monash University, 3800 Victoria (Australia)

    2014-07-28T23:59:59.000Z

    We report nanocrystalline carbon impurities coexisting with graphene synthesized via chemical vapor deposition on platinum. For certain growth conditions, we observe micron-size island-like impurity layers which can be mistaken for second graphene layers in optical microscopy or scanning electron microscopy. The island orientation depends on the crystalline orientation of the Pt, as shown by electron backscatter diffraction, indicating growth of carbon at the platinum surface below graphene. Dark-field transmission electron microscopy indicates that in addition to uniform single-crystal graphene, our sample is decorated with nanocrystalline carbon impurities with a spatially inhomogeneous distribution. The impurity concentration can be reduced significantly by lowering the growth temperature. Raman spectra show a large D peak, however, electrical characterization shows high mobility (?8000?cm{sup 2}/Vs), indicating a limitation for Raman spectroscopy in characterizing the electronic quality of graphene.

  11. The Electronic Structure of Single-Layer Graphene

    E-Print Network [OSTI]

    Siegel, David Alan

    2012-01-01T23:59:59.000Z

    2.11 Graphene Characterization Withof Bilayer Graphene . . . . . . . . . . . . . . . . . .in Monolayer Graphene Matrix Element . . . . . . . . . . .

  12. Graphene-Multilayer Graphene Nanocomposites as Highly Efficient Thermal Interface Materials

    E-Print Network [OSTI]

    resistance at the graphene-matrix interface. KEYWORDS: Graphene, thermal interface materials, nanocompositesGraphene-Multilayer Graphene Nanocomposites as Highly Efficient Thermal Interface Materials Khan M suggest that graphene-multilayer graphene nanocomposite used as the thermal interface material outperforms

  13. Optical Nano-Imaging of Graphene and Beyond | Argonne National...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Optical Nano-Imaging of Graphene and Beyond April 6, 2015 4:00PM to 5:00PM Presenter Zhe Fei, CNM Location Building 241 Type Seminar Series Integrated Imaging Initiative Seminar...

  14. Raman Nanometrology of Graphene.

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01T23:59:59.000Z

    ??Graphene is a two-dimensional honey-comb lattice of carbon atoms with very unusual electron energy dispersion. Since its recent micromechanical isolation and measurements, graphene attracted tremendous… (more)

  15. Functionalization of buckled graphene.

    E-Print Network [OSTI]

    Nelson, Timothy C. (Timothy Chadwick)

    2011-01-01T23:59:59.000Z

    ??Buckled graphene produced by the halogen based etching of 6H-SiC provides a new route for the functionalization of the graphene surface. This surface provides an… (more)

  16. Graphene Frequency Multipliers

    E-Print Network [OSTI]

    Wang, Han

    In this letter, the ambipolar transport properties of graphene flakes have been used to fabricate full-wave signal rectifiers and frequency-doubling devices. By correctly biasing an ambipolar graphene field-effect transistor ...

  17. GRAPHENE: ELECTRON PROPERTIES AND

    E-Print Network [OSTI]

    Gabrieli, John

    GRAPHENE: ELECTRON PROPERTIES AND TRANSPORT PHENOMENA Leonid Levitov MIT Lecture notes and HW and magnetoresistance Quantum Hall effect reminder The half-integer QHE in graphene Energy gaps and splitting of Landau levels QHE in p-n and p-n-p junctions Spin transport at graphene edge Fine structure constant

  18. A graphene electron lens

    SciTech Connect (OSTI)

    Gerhard, L.; Balashov, T.; Wulfhekel, W. [Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Str. 1, 76131 Karlsruhe (Germany); Moyen, E.; Ozerov, I.; Sahaf, H.; Masson, L.; Hanbuecken, M. [CINaM-CNRS, Aix-Marseille University, Campus Luminy - Case 913, 18288 Marseille (France); Portail, M. [CRHEA-CNRS, Parc de Sophia - Antipolis, rue B. Gregory, 06560 Valbonne (France)

    2012-04-09T23:59:59.000Z

    An epitaxial layer of graphene was grown on a pre patterned 6H-SiC(0001) crystal. The graphene smoothly covers the hexagonal nano-holes in the substrate without the introduction of small angle grain boundaries or dislocations. This is achieved by an elastic deformation of the graphene by {approx_equal}0.3% in accordance to its large elastic strain limit. This elastic stretching of the graphene leads to a modification of the band structure and to a local lowering of the electron group velocity of the graphene. We propose to use this effect to focus two-dimensional electrons in analogy to simple optical lenses.

  19. Nauru Island Effect Detection Data Set

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Long, Chuck

    During Nauru99 it was noted that the island was producing small clouds that advected over the ARM site. The Nauru Island Effect Study was run for 1.5 years and the methodology developed to detect the occurrence. Nauru ACRF downwelling SW, wind direction, and air temperature data are used, along with downwelling SW data from Licor radiometers located on the southern end of the island near the airport landing strip. A statistical analysis and comparison of data from the two locations is used to detect the likely occurrence of an island influence on the Nauru ACRF site data

  20. Hot carrier diffusion in graphene

    E-Print Network [OSTI]

    Ruzicka, Brian Andrew; Wang, Shuai; Werake, Lalani Kumari; Weintrub, Ben; Loh, Kian Ping; Zhao, Hui

    2010-11-01T23:59:59.000Z

    We report an optical study of charge transport in graphene. Diffusion of hot carriers in epitaxial graphene and reduced graphene oxide samples are studied using an ultrafast pump-probe technique with a high spatial resolution. Spatiotemporal...

  1. Bilayer Graphene Gets a Bandgap

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bilayer Graphene Gets a Bandgap Bilayer Graphene Gets a Bandgap Print Wednesday, 26 August 2009 00:00 Graphene is the two-dimensional crystalline form of carbon whose extraordinary...

  2. Surprising Quasiparticle Interactions in Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Surprising Quasiparticle Interactions in Graphene Surprising Quasiparticle Interactions in Graphene Print Wednesday, 31 October 2007 00:00 Until now, the world's electronics have...

  3. Epitaxial Graphene - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Epitaxial Graphene Brookhaven National Laboratory Contact BNL About This Technology

    Scanning electron micrographs of epitaxial graphene grown on ruthenium films atop patterned...

  4. Extraordinary nonlinear plasmonics in graphene nanoislands

    E-Print Network [OSTI]

    Cox, Joel D

    2014-01-01T23:59:59.000Z

    Nonlinear optical processes rely on the intrinsically weak interactions between photons enabled by their coupling with matter. Unfortunately, many applications in nonlinear optics are severely hindered by the small response of conventional materials. Metallic nanostructures partially alleviate this situation, as the large light enhancement associated with their localized plasmons amplifies their nonlinear response to record high levels. Graphene hosts long-lived, electrically tunable plasmons that also interact strongly with light. Here we show that the nonlinear polarizabilities of graphene nanoislands can be electrically tuned to surpass by several orders of magnitude those of metal nanoparticles of similar size. This extraordinary behavior extends over the visible and near-infrared for islands consisting of hundreds of carbon atoms doped with moderate carrier densities. Our quantum-mechanical simulations of the plasmon-enhanced optical response of nanographene reveal this material as an ideal platform for ...

  5. Graphene: Materially Better Carbon

    SciTech Connect (OSTI)

    Fuhrer, M. S.; Lau, C. N.; MacDonald, A. H.

    2010-01-01T23:59:59.000Z

    Graphene, a single atom–thick plane of carbon atoms arranged in a honeycomb lattice, has captivated the attention of physicists, materials scientists, and engineers alike over the five years following its experimental isolation. Graphene is a fundamentally new type of electronic material whose electrons are strictly confined to a two-dimensional plane and exhibit properties akin to those of ultrarelativistic particles. Graphene's two-dimensional form suggests compatibility with conventional wafer processing technology. Extraordinary physical properties, including exceedingly high charge carrier mobility, current-carrying capacity, mechanical strength, and thermal conductivity, make it an enticing candidate for new electronic technologies both within and beyond complementary metal oxide semiconductors (CMOS). Immediate graphene applications include high-speed analog electronics and highly conductive, flexible, transparent thin films for displays and optoelectronics. Currently, much graphene research is focused on generating and tuning a bandgap and on novel device structures that exploit graphene's extraordinary electrical, optical, and mechanical properties.

  6. Trifluoromethylation of graphene

    SciTech Connect (OSTI)

    Zhou, Lin; Zhou, Lushan; Wang, Xi; Yu, Jingwen; Yang, Mingmei; Wang, Jianbo; Peng, Hailin, E-mail: zfliu@pku.edu.cn, E-mail: hlpeng@pku.edu.cn; Liu, Zhongfan, E-mail: zfliu@pku.edu.cn, E-mail: hlpeng@pku.edu.cn [Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2014-09-01T23:59:59.000Z

    We demonstrate trifluoromethylation of graphene by copper-catalyzed free radical reaction. The covalent addition of CF{sub 3} to graphene, which changes the carbon atom hybridization from sp{sup 2} to sp{sup 3}, and modifies graphene in a homogeneous and nondestructive manner, was verified with Raman spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. X-ray photoelectron spectroscopy reveals that CF{sub 3} groups are grafted to the basal plane of graphene, with about 4 at. % CF{sub 3} coverage. After trifluoromethylation, the average resistance increases by nearly one order of magnitude, and an energy gap of about 98 meV appears. The noninvasive and mild reaction to synthesize trifluoromethylated graphene paves the way for graphene's applications in electronics and biomedical areas.

  7. Electronic Transport in Few-layer Graphene

    E-Print Network [OSTI]

    Zhao, Zeng

    2013-01-01T23:59:59.000Z

    in Charge Neutral Bilayer Graphene Introduction In thisstudy on heterogeneous graphene devices in a differentto probe few layer graphene to determine their dependence on

  8. Local Density of States in Graphene

    E-Print Network [OSTI]

    Yang, Ling

    2011-01-01T23:59:59.000Z

    Continuum Hamiltonian for the graphene in the presence of afingerprints for adatoms in graphene: scanning tunnelingxi 4.10 Graphene LDOS at the adatom site (top carbon case)

  9. Graphene Growth on Low Carbon Solubility Metals

    E-Print Network [OSTI]

    Wofford, Joseph Monroe

    2012-01-01T23:59:59.000Z

    The electronic properties of graphene. Reviews of Modernand E.A. Sutter, Epitaxial graphene on ruthenium. Natureopening in epitaxial graphene. Nature Materials, 2007. 6(

  10. Electrical Transport in Carbon Nanotubes and Graphene

    E-Print Network [OSTI]

    Liu, Gang

    2010-01-01T23:59:59.000Z

    Introduction to Carbon Nanotubes and Graphene Single wallCarbon nanotubes and graphene are the most popular Carbonin the Normal Metal – Graphene – Superconductor Junctions

  11. Electrical and Thermoelectrical Transport Properties of Graphene

    E-Print Network [OSTI]

    Wang, Deqi

    2011-01-01T23:59:59.000Z

    IV Large Memory Effect in Graphene Based Devices IV-1Transport Properties of Graphene A Dissertation submitted into study the new material, graphene. By investigating the

  12. Electrical and Mechanical Properties of Graphene

    E-Print Network [OSTI]

    Bao, Wenzhong

    2011-01-01T23:59:59.000Z

    Transport in a Suspended Graphene Sheet, Phys. Rev. Lett. ,Novoselov, The rise of graphene, Nat. Mater. , 6 (2007) [24]mobility in suspended graphene, Sol. State Commun. , 146 (

  13. Graphene synthesis & graphene/polymer nanocomposites.

    E-Print Network [OSTI]

    Liao, Ken-Hsuan

    2012-01-01T23:59:59.000Z

    ??Graphene, a two-dimensional carbon sheet with single-atom thickness, has recently attracted significant interest due to its unique mechanical and electrical properties. It has been reported… (more)

  14. Lithium-Mediated Benzene Adsorption on Graphene and Graphene Nanoribbons

    E-Print Network [OSTI]

    Hod, Oded

    Lithium-Mediated Benzene Adsorption on Graphene and Graphene Nanoribbons Dana Krepel and Oded Hod on lithium adsorption sites at the surface of graphene and nanoribbons thereof are investigated. The effects, bare lithium adsorption turns armchair graphene nanoribbons metallic and their zigzag counterparts half

  15. Epitaxial graphene on silicon carbide: Introduction to structured graphene

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Epitaxial graphene on silicon carbide: Introduction to structured graphene Ming Ruan 1 , Yike Hu 1, France Abstract We present an introduction to the rapidly growing field of epitaxial graphene on silicon present, highly evolved state. The potential of epitaxial graphene as a new electronic material is now

  16. Graphene Monolayer Rotation on Ni(111) Facilities Bilayer Graphene Growth

    SciTech Connect (OSTI)

    Batzill M.; Sutter P.; Dahal, A.; Addou, R.

    2012-06-11T23:59:59.000Z

    Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.

  17. Island-finding ability of marine turtles

    E-Print Network [OSTI]

    Hays, Graeme

    of the equatorial Atlantic. To test the hypothesis that turtles use wind-borne cues to locate Ascension Island we back to the island. These find- ings strongly support the hypothesis that wind-borne cues are used that hatch- ling loggerhead turtles (Caretta caretta) have the ability to perceive the inclination

  18. Qualifying RPS State Export Markets (Rhode Island)

    Broader source: Energy.gov [DOE]

    This entry lists the states with Renewable Portfolio Standard (RPS) policies that accept generation located in Rhode Island as eligible sources towards their RPS targets or goals. For specific...

  19. Ultrathin Planar Graphene Supercapacitors

    SciTech Connect (OSTI)

    Huang, Jingsong [ORNL; Meunier, Vincent [ORNL; Sumpter, Bobby G [ORNL; Ajayan, Pullikel M [Rice University; Yoo, Jung Joon [KAIST, Daejeon, Republic of Korea; Balakrishnan, Kaushik [Rice University; Srivastava, Anchal [Rice University; Conway, Michelle [Rice University; Reddy, Arava Leela Mohan [Rice University; Yu, Jin [Rice University; Vajtai, Robert [Rice University

    2011-01-01T23:59:59.000Z

    With the advent of atomically thin and flat layers of conducting materials such as graphene, new designs for thin film energy storage devices with good performance have become possible. Here, we report an in-plane fabrication approach for ultrathin supercapacitors based on electrodes comprised of pristine graphene and multi-layer reduced graphene oxide. The in-plane design is straightforward to implement and exploits efficiently the surface of each graphene layer for energy storage. The open architecture and the effect of graphene edges enable even the thinnest of devices, made from as grown 1-2 graphene layers, to reach specific capacities up to 80 Fcm-2. While, much higher (394 Fcm-2) specific capacities are observed in case of multi-layered graphene oxide electrodes, owing to the better utilization of the available electrochemical surface area. The performances of devices with pristine as well as thicker graphene based structures are examined using a combination of experiments and model calculations. The demonstrated all solid-state supercapacitors provide a prototype for a broad range of thin-film based energy storage devices.

  20. Highly durable graphene nanoplatelets supported Pt nanocatalysts...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    durable graphene nanoplatelets supported Pt nanocatalysts for oxygen reduction . Highly durable graphene nanoplatelets supported Pt nanocatalysts for oxygen reduction . Abstract:...

  1. Polyoxometalate-Graphene Nanocomposite Modified Electrode for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Polyoxometalate-Graphene Nanocomposite Modified Electrode for Electrocatalytic Detection of Ascorbic Acid. Polyoxometalate-Graphene Nanocomposite Modified Electrode for...

  2. Scanning Tunneling Microscopy currents on locally disordered graphene

    E-Print Network [OSTI]

    Tsai, Shan-Wen; Peres, Nuno M. R.; Santos, J. E.; Ribeiro, R. M.

    2009-01-01T23:59:59.000Z

    Intrinsic ripples in graphene“, Nature Materials 6, 858 (Novoselov, ”Control of graphene’s properties by reversiblespectroscopy of monolayer graphene on SiO 2 ”, arXiv:

  3. Nitrogen-doped Graphene and Its Electrochemical Applications...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    doped Graphene and Its Electrochemical Applications. Nitrogen-doped Graphene and Its Electrochemical Applications. Abstract: Nitrogen-doped graphene (N-graphene) is obtained by...

  4. Shielding vacuum fluctuations with graphene

    E-Print Network [OSTI]

    Sofia Ribeiro; Stefan Scheel

    2014-03-14T23:59:59.000Z

    The Casimir-Polder interaction of ground-state and excited atoms with graphene is investigated with the aim to establish whether graphene systems can be used as a shield for vacuum fluctuations of an underlying substrate. We calculate the zero-temperature Casimir-Polder potential from the reflection coefficients of graphene within the framework of the Dirac model. For both doped and undoped graphene we show limits at which graphene could be used effectively as a shield. Additional results are given for AB-stacked bilayer graphene.

  5. Uncertainties in Gapped Graphene

    E-Print Network [OSTI]

    Eylee Jung; Kwang S. Kim; DaeKil Park

    2012-03-20T23:59:59.000Z

    Motivated by graphene-based quantum computer we examine the time-dependence of the position-momentum and position-velocity uncertainties in the monolayer gapped graphene. The effect of the energy gap to the uncertainties is shown to appear via the Compton-like wavelength $\\lambda_c$. The uncertainties in the graphene are mainly contributed by two phenomena, spreading and zitterbewegung. While the former determines the uncertainties in the long-range of time, the latter gives the highly oscillation to the uncertainties in the short-range of time. The uncertainties in the graphene are compared with the corresponding values for the usual free Hamiltonian $\\hat{H}_{free} = (p_1^2 + p_2^2) / 2 M$. It is shown that the uncertainties can be under control within the quantum mechanical law if one can choose the gap parameter $\\lambda_c$ freely.

  6. Levitated Spinning Graphene

    E-Print Network [OSTI]

    B. E. Kane

    2010-06-18T23:59:59.000Z

    A method is described for levitating micron-sized few layer graphene flakes in a quadrupole ion trap. Starting from a liquid suspension containing graphene, charged flakes are injected into the trap using the electrospray ionization technique and are probed optically. At micro-torr pressures, torques from circularly polarized light cause the levitated particles to rotate at frequencies >1 MHz, which can be inferred from modulation of light scattering off the rotating flake when an electric field resonant with the rotation rate is applied. Possible applications of these techniques will be presented, both to fundamental measurements of the mechanical and electronic properties of graphene and to new approaches to graphene crystal growth, modification and manipulation.

  7. Graphene's 3D Counterpart

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    08:59 ALS researchers have discovered a material that is essentially a 3D version of graphene-the 2D sheets of carbon through which electrons race at many times the speed at which...

  8. Faraday rotation in graphene

    E-Print Network [OSTI]

    I. V. Fialkovsky; D. V. Vassilevich

    2012-11-29T23:59:59.000Z

    We study magneto--optical properties of monolayer graphene by means of quantum field theory methods in the framework of the Dirac model. We reveal a good agreement between the Dirac model and a recent experiment on giant Faraday rotation in cyclotron resonance. We also predict other regimes when the effects are well pronounced. The general dependence of the Faraday rotation and absorption on various parameters of samples is revealed both for suspended and epitaxial graphene.

  9. Graphene folding on flat substrates

    SciTech Connect (OSTI)

    Chen, Xiaoming; Zhao, Yadong; Ke, Changhong, E-mail: cke@binghamton.edu [Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902 (United States); Zhang, Liuyang; Wang, Xianqiao [College of Engineering, University of Georgia, Athens, Georgia 30602 (United States)

    2014-10-28T23:59:59.000Z

    We present a combined experimental-theoretical study of graphene folding on flat substrates. The structure and deformation of the folded graphene sheet are experimentally characterized by atomic force microscopy. The local graphene folding behaviors are interpreted based on nonlinear continuum mechanics modeling and molecular dynamics simulations. Our study on self-folding of a trilayer graphene sheet reports a bending stiffness of about 6.57?eV, which is about four times the reported values for monolayer graphene. Our results reveal that an intriguing free sliding phenomenon occurs at the interlayer van der Waals interfaces during the graphene folding process. This work demonstrates that it is a plausible venue to quantify the bending stiffness of graphene based on its self-folding conformation on flat substrates. The findings reported in this work are useful to a better understanding of the mechanical properties of graphene and in the pursuit of its applications.

  10. Twist Solves Bilayer Graphene Mystery

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Twist Solves Bilayer Graphene Mystery Twist Solves Bilayer Graphene Mystery Print Wednesday, 26 March 2014 00:00 Researchers have discovered a unique new twist to the story of...

  11. The effect of substrates on the Raman spectrum of graphene: Graphene-on-sapphire and graphene-on-glass

    E-Print Network [OSTI]

    The effect of substrates on the Raman spectrum of graphene: Graphene- on-sapphire and graphene The authors investigated the influence of substrates on Raman scattering spectrum from graphene. The room-temperature Raman signatures from graphene layers on GaAs, sapphire, and glass substrates were compared with those

  12. Plasmons in Graphene: Fundamental Properties

    E-Print Network [OSTI]

    Soljaèiæ, Marin

    INVITED P A P E R Plasmons in Graphene: Fundamental Properties and Potential Applications in graphene have intriguing fundamen- tal properties and hold great potential for applications. They enable via gate voltage, providing an advantage for graphene's plasmons over surface plasmons (SPs

  13. Island Energy Snapshots

    Office of Energy Efficiency and Renewable Energy (EERE)

    These energy snapshots highlight the energy landscape of islands in the Caribbean and the surrounding area.

  14. Probing graphene defects and estimating graphene quality with optical microscopy

    SciTech Connect (OSTI)

    Lai, Shen [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Center for Human Interface Nanotechnology (HINT), Suwon 440-746 (Korea, Republic of); Kyu Jang, Sung [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Jae Song, Young, E-mail: yjsong@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Department of Physics, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Lee, Sungjoo, E-mail: leesj@skku.edu [SKKU Advanced Institute of Nanotechnology (SAINT), Suwon 440-746 (Korea, Republic of); Center for Human Interface Nanotechnology (HINT), Suwon 440-746 (Korea, Republic of); College of Information and Communication Engineering, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of)

    2014-01-27T23:59:59.000Z

    We report a simple and accurate method for detecting graphene defects that utilizes the mild, dry annealing of graphene/Cu films in air. In contrast to previously reported techniques, our simple approach with optical microscopy can determine the density and degree of dislocation of defects in a graphene film without inducing water-related damage or functionalization. Scanning electron microscopy, confocal Raman and atomic force microscopy, and X-ray photoelectron spectroscopy analysis were performed to demonstrate that our nondestructive approach to characterizing graphene defects with optimized thermal annealing provides rapid and comprehensive determinations of graphene quality.

  15. Cobalt intercalation at the graphene/iridium(111) interface: Influence of rotational domains, wrinkles, and atomic steps

    SciTech Connect (OSTI)

    Vlaic, S.; Kimouche, A.; Coraux, J.; Rougemaille, N. [CNRS, Inst NEEL, F-38042 Grenoble (France) [CNRS, Inst NEEL, F-38042 Grenoble (France); Univ. Grenoble Alpes, Inst NEEL, F-38042 Grenoble (France); Santos, B.; Locatelli, A. [Elettra-Sincrotrone Trieste S.C.p.A., S.S: 14 km 163.5 in AREA Science Park, I-34149 Basovizza, Trieste (Italy)] [Elettra-Sincrotrone Trieste S.C.p.A., S.S: 14 km 163.5 in AREA Science Park, I-34149 Basovizza, Trieste (Italy)

    2014-03-10T23:59:59.000Z

    Using low-energy electron microscopy, we study Co intercalation under graphene grown on Ir(111). Depending on the rotational domain of graphene on which it is deposited, Co is found intercalated at different locations. While intercalated Co is observed preferentially at the substrate step edges below certain rotational domains, it is mostly found close to wrinkles below other domains. These results indicate that curved regions (near substrate atomic steps and wrinkles) of the graphene sheet facilitate Co intercalation and suggest that the strength of the graphene/Ir interaction determines which pathway is energetically more favorable.

  16. Graphene-based structure, method of suspending graphene membrane, and method of depositing material onto graphene membrane

    DOE Patents [OSTI]

    Zettl, Alexander K.; Meyer, Jannik Christian

    2013-04-02T23:59:59.000Z

    An embodiment of a method of suspending a graphene membrane across a gap in a support structure includes attaching graphene to a substrate. A pre-fabricated support structure having the gap is attached to the graphene. The graphene and the pre-fabricated support structure are then separated from the substrate which leaves the graphene membrane suspended across the gap in the pre-fabricated support structure. An embodiment of a method of depositing material includes placing a support structure having a graphene membrane suspended across a gap under vacuum. A precursor is adsorbed to a surface of the graphene membrane. A portion of the graphene membrane is exposed to a focused electron beam which deposits a material from the precursor onto the graphene membrane. An embodiment of a graphene-based structure includes a support structure having a gap, a graphene membrane suspended across the gap, and a material deposited in a pattern on the graphene membrane.

  17. Graphene based Ultra-Thin Flat Lenses

    E-Print Network [OSTI]

    Kong, Xiang-Tian; Khan, Ammar A.; Kidambi, Piran R.; Deng, Sunan; Yetisen, Ali K.; Dlubak, Bruno; Hiralal, Pritesh; Montelongo, Yunuen; Bowen, James; Xavier, Stéphane; Jiang, Kyle; Amaratunga, Gehan A. J.; Hofmann, Stephan; Wilkinson, Timothy D.; Dai, Qing; Butt, Haider

    2015-01-07T23:59:59.000Z

    on graphene, the world’s thinnest known material. Monolayers and low number multilayers of graphene were fabricated into Fresnel zones to produce Fresnel zone plates which utilize the reflection and transmission properties of graphene for their operation...

  18. A Model Graphene Diffraction Pattern Frank Rioux

    E-Print Network [OSTI]

    Rioux, Frank

    A Model Graphene Diffraction Pattern Frank Rioux The purpose of this tutorial is to model graphene d Pj k px j py k 2 i 1 A Graphene Model Diffraction Pattern #12;

  19. Electromechanical Properties of Suspended Graphene Nanoribbons

    E-Print Network [OSTI]

    Hod, Oded

    Electromechanical Properties of Suspended Graphene Nanoribbons Oded Hod* School of Chemistry Manuscript Received May 19, 2009 ABSTRACT Graphene nanoribbons present diverse electronic properties ranging theory considerations, we find a remarkable Young's modulus value of 7 TPa for ultranarrow graphene

  20. Chemistry at the Dirac Point of Graphene

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01T23:59:59.000Z

    Martinez, G. Epitaxial Graphene. Solid State Commun. 2007,92-100. Boehm, H. P. Graphene-How a Laboratory CuriosityK. S. The Rise of Graphene. Nat. Mater. 2007, Novoselov, K.

  1. Optimal traps in graphene

    E-Print Network [OSTI]

    C. A. Downing; A. R. Pearce; R. J. Churchill; M. E. Portnoi

    2015-03-27T23:59:59.000Z

    We transform the two-dimensional Dirac-Weyl equation, which governs the charge carriers in graphene, into a non-linear first-order differential equation for scattering phase shift, using the so-called variable phase method. This allows us to utilize the Levinson Theorem to find zero-energy bound states created electrostatically in realistic structures. These confined states are formed at critical potential strengths, which leads to us posit the use of `optimal traps' to combat the chiral tunneling found in graphene, which could be explored experimentally with an artificial network of point charges held above the graphene layer. We also discuss scattering on these states and find the zero angular momentum states create a dominant peak in scattering cross-section as energy tends towards the Dirac point energy, suggesting a dominant contribution to resistivity.

  2. Graphene's 3D Counterpart

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr Flickr Editor'sshortGeothermalGo BackGrants &GrapheneGraphene

  3. Graphene Growth on Low Carbon Solubility Metals.

    E-Print Network [OSTI]

    Wofford, Joseph Monroe

    2012-01-01T23:59:59.000Z

    ??Advances in synthesis are imperative if graphene is to fulfill its scientific and technological potential. Single crystal graphene of is currently available only in the… (more)

  4. Quantum Hall Effect in Hydrogenated Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Magnetometer for the NHMFL DC Field Facility 07 Quantum Hall Effect in Hydrogenated Graphene 08 Spin Phase Transition in Bilayer Graphene at Charge Neutrality 09...

  5. Chemistry at the Dirac Point of Graphene

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01T23:59:59.000Z

    Haddon, R. C. Covalent Chemistry for Graphene Electronics.P. K. ; Yang, J. X. The Chemistry of Graphene. J. Mater.R. C. Organometallic Chemistry of Extended Periodic ?-

  6. First Observation of Plasmarons in Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    First Observation of Plasmarons in Graphene First Observation of Plasmarons in Graphene Print Wednesday, 30 June 2010 00:00 An international team of scientists performing...

  7. Washington: Graphene Nanostructures for Lithium Batteries Recieves...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Washington: Graphene Nanostructures for Lithium Batteries Recieves 2012 R&D 100 Award Washington: Graphene Nanostructures for Lithium Batteries Recieves 2012 R&D 100 Award February...

  8. Facile and controllable electrochemical reduction of graphene...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and controllable electrochemical reduction of graphene oxide and its applications. Facile and controllable electrochemical reduction of graphene oxide and its applications....

  9. A Roadmap for Engineering Piezoelectricity in Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Roadmap for Engineering Piezoelectricity in Graphene A Roadmap for Engineering Piezoelectricity in Graphene Doping this 'Miracle Material' May Lead to New Array of Nanoscale...

  10. Transverse Electronic Transport through DNA Nucleotides with Functionalized Graphene Electrodes

    E-Print Network [OSTI]

    Prasongkit, Jariyanee; Pathak, Biswarup; Ahuja, Rajeev; Scheicher, Ralph H

    2013-01-01T23:59:59.000Z

    Graphene nanogaps and nanopores show potential for the purpose of electrical DNA sequencing, in particular because single-base resolution appears to be readily achievable. Here, we evaluated from first principles the advantages of a nanogap setup with functionalized graphene edges. To this end, we employed density functional theory and the non-equilibrium Green's function method to investigate the transverse conductance properties of the four nucleotides occurring in DNA when located between the opposing functionalized graphene electrodes. In particular, we determined the electrical tunneling current variation as a function of the applied bias and the associated differential conductance at a voltage which appears suitable to distinguish between the four nucleotides. Intriguingly, we observe for one of the nucleotides a negative differential resistance effect.

  11. Interlayer Interaction and Electronic Screening in Multilayer Graphene

    E-Print Network [OSTI]

    Ohta, Taisuke; Bostwick, Aaron; McChesney, J.L.; Seyller, Thomas; Horn, Karsten; Rotenberg, Eli

    2008-01-01T23:59:59.000Z

    stacking sequences of the graphene layers. The interlayerin the multilayer graphene. Exploiting the sensitivity offor three and four layer graphene. We ?nd the inter- layer

  12. Hierarchically Porous Graphene as a Lithium-Air Battery Electrode...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hierarchically Porous Graphene as a Lithium-Air Battery Electrode. Hierarchically Porous Graphene as a Lithium-Air Battery Electrode. Abstract: Functionalized graphene sheets (FGS)...

  13. Graphene as the Ultimate Membrane for Gas Separation Project...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Graphene as the Ultimate Membrane for Gas Separation Graphene as the Ultimate Membrane for Gas Separation GraphenePore.jpg Key Challenges: Investigate the permeability and...

  14. Graphene and its Hybrid Nanostructures for Nanoelectronics and Energy Applications

    E-Print Network [OSTI]

    LIN, JIAN

    2011-01-01T23:59:59.000Z

    modification of graphene. Advanced Materials, 2008. 20 (16):S. Novoselov. The rise of graphene. Nature Materials, 2007.transport in suspended graphene. Nature Nanotechnology,

  15. Optical Determination of Gate--Tunable Bandgap in Bilayer Graphene

    E-Print Network [OSTI]

    Zhang, Yuanbo

    2010-01-01T23:59:59.000Z

    Tunable Bandgap in Bilayer Graphene Yuanbo Zhang* 1 , Tsung-gate-tunable bandgap in graphene bilayers with magnitude asbands. In two- dimensional graphene bilayers this bandgap

  16. Experimental Studies of Oxide Magnetic Tunnel Junctions and Graphene

    E-Print Network [OSTI]

    Liu, Xinfei

    2012-01-01T23:59:59.000Z

    electron interaction in graphene. The central Nernst peak83, 6694 (1998). Chapter IV Introduction to Graphene IV-1Discovery of Graphene Carbon-based electronic materials have

  17. Chemical Vapor Deposition-Derived Graphene with Electrical Performance of Exfoliated Graphene

    E-Print Network [OSTI]

    Hone, James

    Chemical Vapor Deposition-Derived Graphene with Electrical Performance of Exfoliated Graphene a scalable method to produce large-area graphene, CVD-grown graphene has heretofore exhibited inferior of CVD-grown graphene in which two important sources of disorder, namely grain boundaries and processing

  18. Spectroscopic Raman Nanometrology of Graphene and Graphene Multilayers on Arbitrary Substrates

    E-Print Network [OSTI]

    Spectroscopic Raman Nanometrology of Graphene and Graphene Multilayers on Arbitrary Substrates I to be an effective tool for characterization of graphene and graphene multilayers on the standard Si/SiO2 (300 nm) substrates, which allows one to determine non-destructively the number of the graphene layers and assess

  19. Hydrogen adsorption on Graphene and Nitrogen Doped Graphene Monolayers: A First Principles Study

    E-Print Network [OSTI]

    Petta, Jason

    Hydrogen adsorption on Graphene and Nitrogen Doped Graphene Monolayers: A First Principles Study Abstract This study examines the properties of graphene and nitrogen doped graphene by way of first principles spin-polarized Density Functional Theory calculations. Why graphene is so unique comes from

  20. Graphene growth on glass 1 Synthesis of conducting transparent few-layer graphene directly

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Graphene growth on glass 1 Synthesis of conducting transparent few-layer graphene directly on glass major hurdles that research has to overcome to get graphene out of research laboratories. Here, using transparent graphene layers at temperatures as low as 450 °C. Our few-layer graphene grows at the interface

  1. Cyclotron Resonance in Bilayer Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonance in Bilayer Graphene PI: Horst Stormer, Department of Physics, Columbia University Supported by NSF (DMR-03-52738 and CHE-0117752), ONR (N000150610138) DOE...

  2. Waveguide engineering of graphene's nonlinearity

    E-Print Network [OSTI]

    Ooi, Kelvin J A; Tan, Dawn T H

    2014-01-01T23:59:59.000Z

    Graphene has recently been shown to possess giant nonlinearity; however, the utility of this nonlinearity is limited due to high losses and small interaction volume. We show that by performing waveguide engineering to graphene's nonlinearity, we are able to dramatically increase the nonlinear parameter and decrease the switching optical power to sub-watt levels. Our design makes use of the hybrid plasmonic waveguide and careful manipulation of graphene's refractive index by tuning its Fermi level. The ability to tailor the nonlinear parameter in graphene based waveguides via the Fermi level provides a paradigm of nonlinear optics devices to be realized.

  3. Surprising Quasiparticle Interactions in Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Surprising Quasiparticle Interactions in Graphene Print Until now, the world's electronics have been dominated by silicon, whose properties, while excellent, significantly limit...

  4. Dry-cleaning of graphene

    SciTech Connect (OSTI)

    Algara-Siller, Gerardo [Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, Ulm University, Albert-Einstein-Allee 11, Ulm 89081 (Germany); Department of Chemistry, Technical University Ilmenau, Weimarer Strasse 25, Ilmenau 98693 (Germany); Lehtinen, Ossi; Kaiser, Ute, E-mail: ute.kaiser@uni-ulm.de [Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, Ulm University, Albert-Einstein-Allee 11, Ulm 89081 (Germany); Turchanin, Andrey [Faculty of Physics, University of Bielefeld, Universitätsstr. 25, Bielefeld 33615 (Germany)

    2014-04-14T23:59:59.000Z

    Studies of the structural and electronic properties of graphene in its pristine state are hindered by hydrocarbon contamination on the surfaces. Also, in many applications, contamination reduces the performance of graphene. Contamination is introduced during sample preparation and is adsorbed also directly from air. Here, we report on the development of a simple dry-cleaning method for producing large atomically clean areas in free-standing graphene. The cleanness of graphene is proven using aberration-corrected high-resolution transmission electron microscopy and electron spectroscopy.

  5. Magnetic Edge States in Graphene

    E-Print Network [OSTI]

    Gabriela Murguia

    2010-08-29T23:59:59.000Z

    Magnetic confinement in graphene has been of recent and growing interest because its potential applications in nanotechnology. In particular, the observation of the so called magnetic edge states in graphene has opened the possibility to deepen into the generation of spin currents and its applications in spintronics. We study the magnetic edge states of quasi-particles arising in graphene monolayers due to an inhomogeneous magnetic field of a magnetic barrier in the formalism of the two-dimensional massless Dirac equation. We also show how the solutions of such states in each of both triangular sublattices of the graphene are related through a supersymmetric transformation in the quantum mechanical sense.

  6. Thermal Transport in Graphene Multilayers and Nanoribbons

    E-Print Network [OSTI]

    Subrina, Samia

    2011-01-01T23:59:59.000Z

    always possible to mechanically exfoliate graphene flake ofdifficult to mechanically exfoliate FLG of the same geometry

  7. Graphene Physics L.A. Falkovsky

    E-Print Network [OSTI]

    Titov, Anatoly

    Graphene Physics L.A. Falkovsky Landau Institute for Theoretical Physics #12;outline · electron dispersion in graphene, graphene bilayer and graphite · conductivity in optical region · universal dynamical conductivity of graphene · Kerr effect and reflectivity in magnetic field #12;#12;Novoselov et al (2005)Field

  8. Qualifying RPS Market States (Prince Edward Island, Canada)

    Broader source: Energy.gov [DOE]

    This entry lists the states with RPS policies that accept generation located in Prince Edward Island, Canada as eligible sources towards their Renewable Portfolio Standard targets or goals. For...

  9. Inch-Scale High Throughput Metrology of Graphene and Patterned Graphene Oxide

    E-Print Network [OSTI]

    Pleskot, Dennis

    2013-01-01T23:59:59.000Z

    Strength of Monolayer Graphene Science 2008 321, 385-388. 5.Novoselov, K. S. The rise of graphene Nature 2007 6 183-191.A. Thermal properties of graphene and nanostructured carbon

  10. Photon-induced tunneling in graphene-boron nitride-graphene heterostructures

    E-Print Network [OSTI]

    Nair, Nityan

    2013-01-01T23:59:59.000Z

    Graphene is a material that has generated much interest due to its many unique electronic and optical properties. In this work, we present optoelectronic measurements performed on ultrathin graphene-boron nitride-graphene ...

  11. Graphene Device Fabrication and Applications in Communication Systems

    E-Print Network [OSTI]

    Liu, Guanxiong

    2012-01-01T23:59:59.000Z

    The dark color regions are graphene and the light color isElectrical Characterization Graphene Devices 3.1 ElectricalMeasurement of Back-Gate Graphene Device Graphene is a very

  12. Husimi Maps in Graphene

    E-Print Network [OSTI]

    Douglas J. Mason; Mario F. Borunda; Eric J. Heller

    2012-06-08T23:59:59.000Z

    We present a method for bridging the gap between the Dirac effective field theory and atomistic simulations in graphene based on the Husimi projection, allowing us to depict phenomena in graphene at arbitrary scales. This technique takes the atomistic wavefunction as an input, and produces semiclassical pictures of quasiparticles in the two Dirac valleys. We use the Husimi tech- nique to produce maps of the scattering behavior of boundaries, giving insight into the properties of wavefunctions at energies both close to and far from the Dirac point. Boundary conditions play a significant role to the rise of Fano resonances, which we examine using the Husimi map to deepen our understanding of bond currents near resonance.

  13. Quantum Field Theory in Graphene

    E-Print Network [OSTI]

    I. V. Fialkovsky; D. V. Vassilevich

    2011-11-18T23:59:59.000Z

    This is a short non-technical introduction to applications of the Quantum Field Theory methods to graphene. We derive the Dirac model from the tight binding model and describe calculations of the polarization operator (conductivity). Later on, we use this quantity to describe the Quantum Hall Effect, light absorption by graphene, the Faraday effect, and the Casimir interaction.

  14. Coulomb impurity in graphene

    E-Print Network [OSTI]

    Rudro R. Biswas; Subir Sachdev; Dam T. Son

    2007-11-29T23:59:59.000Z

    We consider the problem of screening of an electrically charged impurity in a clean graphene sheet. When electron-electron interactions are neglected, the screening charge has a sign opposite to that of the impurity, and is localized near the impurity. Interactions between electrons smear out the induced charge density to give a large-distance tail that follows approximately, but not exactly, an r^{-2} behavior and with a sign which is the same as that of the impurity.

  15. Turbulent flow in graphene

    E-Print Network [OSTI]

    Kumar S. Gupta; Siddhartha Sen

    2010-06-05T23:59:59.000Z

    We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.

  16. Graphene electron cannon: High-current edge emission from aligned graphene sheets

    SciTech Connect (OSTI)

    Liu, Jianlong; Li, Nannan; Guo, Jing; Fang, Yong; Deng, Jiang [National Key Laboratory of Science and Technology on Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zeng, Baoqing, E-mail: bqzeng@uestc.edu.cn [National Key Laboratory of Science and Technology on Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); State Key Laboratory of Electronic Thin Films and Integrated Devices Zhongshan Lab, Department of Electronic Engineering, University of Electronic Science and Technology of China Zhongshan Institute, Zhongshan 528402 (China); Wang, Wenzhong; Li, Jiangnan; Hao, Chenchun [School of Science, Minzu University of China, Beijing 100081 (China)

    2014-01-13T23:59:59.000Z

    High-current field emitters are made by graphene paper consist of aligned graphene sheets. Field emission luminance pattern shows that their electron beams can be controlled by rolling the graphene paper from sheet to cylinder. These specific electron beams would be useful to vacuum devices and electron beam lithograph. To get high-current emission, the graphene paper is rolled to array and form graphene cannon. Due to aligned emission array, graphene cannon have high emission current. Besides high emission current, the graphene cannon is also tolerable with excellent emission stability. With good field emission properties, these aligned graphene emitters bring application insight.

  17. Inch-Scale High Throughput Metrology of Graphene and Patterned Graphene Oxide.

    E-Print Network [OSTI]

    Pleskot, Dennis

    2013-01-01T23:59:59.000Z

    ??Abstract Inch-Scale High Throughput Metrology of Graphene and Patterned Graphene Oxide by Dennis Pleskot Master of Science, Graduate Program in Materials Science and Engineering University… (more)

  18. Controllable N-Doping of Graphene Beidou Guo,,

    E-Print Network [OSTI]

    Gong, Jian Ru

    Controllable N-Doping of Graphene Beidou Guo,, Qian Liu, Erdan Chen, Hewei Zhu, Liang Fang in graphene are central to many electronic applications of graphene. Here we report N-doped graphene obtained by NH3 annealing after N+ -ion irradiation of graphene samples. First, the evolution of the graphene

  19. Direct comparison of graphene devices before and after transfer to different substrates

    SciTech Connect (OSTI)

    Sachs, Raymond; Lin, Zhisheng; Odenthal, Patrick; Kawakami, Roland; Shi, Jing [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States)

    2014-01-20T23:59:59.000Z

    The entire graphene field-effect-transistor devices first fabricated on SiO{sub 2}/Si are peeled from the surface and placed on a different wafer. Both longitudinal and transverse resistivity measurements of the devices before and after the transfer are measured to calculate the mobility for a direct comparison. After transferred to different SiO{sub 2}/Si wafers, the mobility, generally, is comparable, and the defect density does not show any significant increase, which indicates the degradation due to the transfer process itself is minimal. The same method can be applied to transfer graphene devices to any arbitrary substrates (e.g., SrTiO{sub 3} or STO). The transfer method developed here not only eliminates the need to locate single-layer graphene on non-SiO{sub 2}/Si substrates for patterning but also provides a convenient way to study the effects of various substrates on graphene electronic properties.

  20. Directional excitation of graphene surface plasmons

    E-Print Network [OSTI]

    Liu, Fangli; Chong, Y D

    2014-01-01T23:59:59.000Z

    We propose a scheme to directionally couple light into graphene plasmons by placing a graphene sheet on a magneto-optical substrate. When a magnetic field is applied parallel to the surface, the graphene plasmon dispersion relation becomes asymmetric in the forward and backward directions. It is possible to achieve unidirectional excitation of graphene plasmons with normally incident illumination by applying a grating to the substrate. The directionality can be actively controlled by electrically gating the graphene, or by varying the magnetic bias. This scheme may have applications in graphene-based opto-electronics and sensing.

  1. Smart antennas based on graphene

    SciTech Connect (OSTI)

    Aldrigo, Martino; Dragoman, Mircea, E-mail: mircea.dragoman@imt.ro [National Institute for Research and Development in Microtechnology (IMT), P.O. Box 38-160, 023573 Bucharest (Romania); Dragoman, Daniela [Physics Faculty, University of Bucharest, P.O. Box MG-11, 077125 Bucharest (Romania)

    2014-09-21T23:59:59.000Z

    We report two configurations of smart graphene antennas, in which either the radiation pattern of the antenna or the backscattering of the periodic metallic arrays is controlled by DC biases that induce metal-insulator reversible transitions of graphene monolayers. Such a transition from a high surface resistance (no bias) to a low surface resistance state (finite bias voltage) causes the radiation pattern of metallic antennas backed with graphene to change dramatically, from omnidirectional to broadside. Moreover, reflectarrays enhance the backscattered field due to the same metal-dielectric transition.

  2. Phonon dispersion in graphene

    E-Print Network [OSTI]

    L. A. Falkovsky

    2007-08-11T23:59:59.000Z

    Taking into account the constraints imposed by the lattice symmetry, the phonon dispersion is calculated for graphene with interactions between the first and second nearest neighbors in the framework of the Born-von Karman model. Analytical expressions are obtained for the out-of-plane (bending) modes determined only by two force constants as well as for the in-plane modes with four force constants. Values of the force constants are found in fitting to elastic constants and Raman frequencies observed in graphite.

  3. Graphene's 3D Counterpart

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky LearningGet AssistanceCatalyticNationalMansfieldGraphene's 3D

  4. Graphene's 3D Counterpart

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky LearningGet AssistanceCatalyticNationalMansfieldGraphene's

  5. Graphene's 3D Counterpart

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky LearningGetGraphene's 3D Counterpart Print ALS researchers have

  6. Graphene's 3D Counterpart

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky LearningGetGraphene's 3D Counterpart Print ALS researchers

  7. Graphene's 3D Counterpart

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky LearningGetGraphene's 3D Counterpart Print ALS

  8. Controlling Graphene's Electronic Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01 SF-30InnovationinControlling Graphene's

  9. Controlling Graphene's Electronic Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01Controlling Graphene's Electronic Structure

  10. Controlling Graphene's Electronic Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01Controlling Graphene's Electronic

  11. Comparison of the Catalytic Oxidation Reaction on Graphene Oxide and Reduced Graphene Oxide

    E-Print Network [OSTI]

    Kim, Sehun

    Comparison of the Catalytic Oxidation Reaction on Graphene Oxide and Reduced Graphene Oxide Laboratory (PAL), Pohang 790-784, Republic of Korea ABSTRACT: The capacities of graphene oxide (GO) and reduced graphene oxide (rGO) films grown on silicon substrate to cause the aniline to azobenzene oxidation

  12. Variable temperature Raman microscopy as a nanometrology tool for graphene layers and graphene-based devices

    E-Print Network [OSTI]

    Variable temperature Raman microscopy as a nanometrology tool for graphene layers and graphene; accepted 24 July 2007; published online 15 August 2007 Raman microscopy of graphene was carried out over-band frequencies extracted from Raman spectra of the single-layer graphene are - 1.6±0.2 10-2 cm-1 /K and - 3

  13. PHYSICAL REVIEW B 85, 195405 (2012) Graphene on Ru(0001): Evidence for two graphene band structures

    E-Print Network [OSTI]

    Goodman, Wayne

    PHYSICAL REVIEW B 85, 195405 (2012) Graphene on Ru(0001): Evidence for two graphene band structures) High-resolution photoemission illustrates that the band structure of graphene on Ru(0001) exhibits a well- defined splitting. This splitting is largest with the graphene directly on the Ru(0001) substrate

  14. Nanoscale tunable reduction of graphene oxide for graphene electronics , D. Wang2*

    E-Print Network [OSTI]

    Nanoscale tunable reduction of graphene oxide for graphene electronics Z. Wei1* , D. Wang2* , S contributed equally to this work. paul.sheehan@nrl.navy.mil elisa.riedo@physics.gatech.edu Graphene is now in graphene oxide (GO) has risen for producing large-scale flexible conductors and for its potential to open

  15. Surface functionalization of graphene devices

    E-Print Network [OSTI]

    Zhang, Xu, S.M. Massachusetts Institute of Technology

    2012-01-01T23:59:59.000Z

    Graphene, a zero-gap semiconductor with massless charge carriers, is emerging as an amazing material for future electronics, due to its outstanding electrical and mechanical performances. However, the lack of a bandgap ...

  16. Chiral Gauge Theory for Graphene

    E-Print Network [OSTI]

    R. Jackiw; S. -Y. Pi

    2007-05-04T23:59:59.000Z

    We construct a chiral gauge theory to describe fractionalization of fermions in graphene. Thereby we extend a recently proposed model, which relies on vortex formation. Our chiral gauge fields provide dynamics for the vortices and also couple to the fermions.

  17. Four Dimensional Graphene

    E-Print Network [OSTI]

    L. B Drissi; E. H Saidi; M. Bousmina

    2011-06-26T23:59:59.000Z

    Mimicking pristine 2D graphene, we revisit the BBTW model for 4D lattice QCD given in ref.[5] by using the hidden SU(5) symmetry of the 4D hyperdiamond lattice H_4. We first study the link between the H_4 and SU(5); then we refine the BBTW 4D lattice action by using the weight vectors \\lambda_1, \\lambda_2, \\lambda_3, \\lambda_4, \\lambda_5 of the 5-dimensional representation of SU(5) satisfying {\\Sigma}_i\\lambda_i=0. After that we study explicitly the solutions of the zeros of the Dirac operator D in terms of the SU(5) simple roots \\alpha_1, \\alpha_2, \\alpha_3, \\alpha_4 generating H_4; and its fundamental weights \\omega_1, \\omega_2, \\omega_3, \\omega_4 which generate the reciprocal lattice H_4^\\ast. It is shown, amongst others, that these zeros live at the sites of H_4^\\ast; and the continuous limit D is given by ((id\\surd5)/2) \\gamma^\\muk_\\mu with d, \\gamma^\\mu and k_\\mu standing respectively for the lattice parameter of H_4, the usual 4 Dirac matrices and the 4D wave vector. Other features such as differences with BBTW model as well as the link between the Dirac operator following from our construction and the one suggested by Creutz using quaternions, are also given. Keywords: Graphene, Lattice QCD, 4D hyperdiamond, BBTW model, SU(5) Symmetry.

  18. Unconventional plasmon-phonon coupling in graphene

    E-Print Network [OSTI]

    Jablan, Marinko

    We predict the existence of coupled plasmon-phonon excitations in graphene by using the self-consistent linear response formalism. The unique electron-phonon interaction in graphene leads to unconventional mixing of plasmon ...

  19. Breakdown in the Wetting Transparency of Graphene

    E-Print Network [OSTI]

    Shih, Chih-Jen

    We develop a theory to model the van der Waals interactions between liquid and graphene, including quantifying the wetting behavior of a graphene-coated surface. Molecular dynamics simulations and contact angle measurements ...

  20. Transverse electric plasmons in bilayer graphene

    E-Print Network [OSTI]

    Jablan, Marinko

    We predict the existence of transverse electric (TE) plasmons in bilayer graphene. We find that their plasmonic properties are much more pronounced in bilayer than in monolayer graphene, in a sense that they can get more ...

  1. Applications of Graphene Devices in RF Communications

    E-Print Network [OSTI]

    Palacios, Tomas

    Graphene, a one-atom-thick layer of carbon atoms arranged in a honeycomb lattice, has recently attracted great interest among physicists and engineers. The combination of the unique properties of graphene with new device ...

  2. Studies of bilayer and trilayer graphene

    E-Print Network [OSTI]

    Cela, Devin Artan

    2013-01-01T23:59:59.000Z

    Graphene is a single 2-dimensional atomic layer of hexagonally packed carbon atoms. Graphene has a unique combination of thermal, mechanical, and electronic properties, making it a useful tool for learning new physics as ...

  3. Cleaning graphene with a titanium sacrificial layer

    SciTech Connect (OSTI)

    Joiner, C. A., E-mail: cjoiner3@gatech.edu; Roy, T.; Hesabi, Z. R.; Vogel, E. M. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Chakrabarti, B. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2014-06-02T23:59:59.000Z

    Graphene is a promising material for future electronic applications and chemical vapor deposition of graphene on copper is a promising method for synthesizing graphene on the wafer scale. The processing of such graphene films into electronic devices introduces a variety of contaminants which can be difficult to remove. An approach to cleaning residues from the graphene channel is presented in which a thin layer of titanium is deposited via thermal e-beam evaporation and immediately removed. This procedure does not damage the graphene as evidenced by Raman spectroscopy, greatly enhances the electrical performance of the fabricated graphene field effect transistors, and completely removes the chemical residues from the surface of the graphene channel as evidenced by x-ray photoelectron spectroscopy.

  4. Conservation Strategy for Sable Island

    E-Print Network [OSTI]

    Jones, Ian L.

    Towards a Conservation Strategy for Sable Island Environment Canada, Canadian Wildlife Service, Atlantic Region #12;SABLE ISLAND CONSERVATION STRATEGY page - i March, 1998 A CONSERVATION STRATEGY FOR SABLE ISLAND PREPARED BY This Conservation Strategy for Sable Island was prepared for Environment Canada

  5. Plasmons in graphene on uniaxial substrates

    SciTech Connect (OSTI)

    Arrazola, I. [Universidad del País Vasco, 48940 Leioa (Spain) [Universidad del País Vasco, 48940 Leioa (Spain); CIC nanoGUNE Consolider, 20018 Donostia-San Sebastián (Spain); Hillenbrand, R.; Nikitin, A. Yu., E-mail: alexeynik@rambler.ru [CIC nanoGUNE Consolider, 20018 Donostia-San Sebastián (Spain); Ikerbasque, Basque Foundation for Science, 48011 Bilbao (Spain)

    2014-01-06T23:59:59.000Z

    Placing graphene on uniaxial substrates may have interesting application potential for graphene-based photonic and optoelectronic devices. Here, we analytically derive the dispersion relation for graphene plasmons on uniaxial substrates and discuss their momentum, propagation length, and polarization as a function of frequency, propagation direction, and both ordinary and extraordinary dielectric permittivities of the substrate. We find that the plasmons exhibit an anisotropic propagation, yielding radially asymmetric field patterns when a point emitter launches plasmons in the graphene layer.

  6. Adsorbing H{sub 2}S onto a single graphene sheet: A possible gas sensor

    SciTech Connect (OSTI)

    Reshak, A. H., E-mail: maalidph@yahoo.co.uk [New Technologies-Research Centre, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Auluck, S. [Council of Scientific and Industrial Research-National Physical Laboratory, Dr. K S Krishnan Marg, New Delhi 110012 (India)

    2014-09-14T23:59:59.000Z

    The electronic structure of pristine graphene sheet and the resulting structure of adsorbing a single molecule of H{sub 2}S on pristine graphene in three different sites (bridge, top, and hollow) are studied using the full potential linearized augmented plane wave method. Our calculations show that the adsorption of H{sub 2}S molecule on the bridge site opens up a small direct energy gap of about 0.1?eV at symmetry point M, while adsorption of H{sub 2}S on top site opens a gap of 0.3?eV around the symmetry point K. We find that adsorbed H{sub 2}S onto the hollow site of pristine graphene sheet causes to push the conduction band minimum and the valence band maximum towards Fermi level resulting in a metallic behavior. Comparing the angular momentum decomposition of the atoms projected electronic density of states of pristine graphene sheet with that of H{sub 2}S–graphene for three different cases, we find a significant influence of the location of the H{sub 2}S molecule on the electronic properties especially the strong hybridization between H{sub 2}S molecule and graphene sheet.

  7. Interconnection Guidelines (Rhode Island)

    Broader source: Energy.gov [DOE]

    Rhode Island enacted legislation (HB 6222) in June 2011 to standardize the application process for the interconnection of customer-sited renewable-energy systems to the state’s distribution grid....

  8. Forestry Policies (Rhode Island)

    Broader source: Energy.gov [DOE]

    Rhode Island's forests cover over half of the state's land area, and are managed by the Department of Environmental Management, Division of Forest Environment. The State issued its "Forest...

  9. Seminar -4. letnik Landau Levels in Graphene

    E-Print Network [OSTI]

    Ramsak, Anton

    Seminar - 4. letnik Landau Levels in Graphene Author: Zala Lenarcic Mentor: prof. Anton Ramsak Ljubljana, December 2010 Abstract In this seminar I present graphene, a new material with promising to graphene's unusual energy dispersion. I will derive Landau levels for standard electrons, for electrons

  10. Quantum Transport in Graphene Bernard Plaais

    E-Print Network [OSTI]

    Plaçais, Bernard

    Quantum Transport in Graphene Bernard Plaçais d h i é i (MESO)groupe de physique mésoscopique (MESO 2011 2 (K. Novoselov et al., Science 2004) #12;Suspending graphene (2008) (Temperature dependent transport in suspended graphene, K.I. Bolotin et al. PRL2008) Wh t th fi i t f Di f i ? What

  11. Charge Noise in Graphene Transistors Iddo Heller,,

    E-Print Network [OSTI]

    Dekker, Cees

    Charge Noise in Graphene Transistors Iddo Heller,,§ Sohail Chatoor, Jaan Ma¨nnik, Marcel A. G an experimental study of 1/f noise in liquid-gated graphene transistors. We show that the gate dependence to the graphene, while at high carrier density it is consistent with noise due to scattering in the channel

  12. Technical Note Graphene: Substrate preparation and introduction

    E-Print Network [OSTI]

    of Texas, Austin, TX, USA c Electron Microscopy Department of Materials Sciences, University of Ulm, Ulm September 2010 Accepted 4 October 2010 Available online xxxx Keywords: Graphene Graphene oxide Cryo-EM graphene substrates as well as their ongoing development. Ã? 2010 Elsevier Inc. All rights reserved. 1

  13. Graphene Ferroelectric Heterostructures Santosh Raghavan1

    E-Print Network [OSTI]

    Dalang, Robert C.

    Graphene Ferroelectric Heterostructures Santosh Raghavan1 , Dr. Jean-Savin Heron2 , Dr. Igor] Laboratory of Nanoscale Electronics and Structures, IEL, EPFL S D1 2 Doped Silicon SiO2 Graphene 3 4 1 2S D L Introduction Working Principle Graphene PVDF (-TrFE) PFM Measurements Retention Measurements Conclusion

  14. Graphene plasmonics for tunable terahertz metamaterials

    E-Print Network [OSTI]

    Wang, Feng

    Graphene plasmonics for tunable terahertz metamaterials Long Ju1 , Baisong Geng1,6 , Jason Horng1 metamaterials1­3 . Plasmons of two-dimensional massless electrons, as present in graphene, show unusual graphene micro- ribbonarrays.Wedemonstratethatgrapheneplasmonresonances can be tuned over a broad terahertz

  15. Graphene-enabled Wireless Communication Networks

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    Graphene-enabled Wireless Communication Networks at the Nanoscale 1 Ignacio Llatser Nanonetworking;Graphene Honeycomb lattice of carbon atoms 2-dimensional material Discovered by A. K. Geim and K. S. Novoselov 9 Graphene G. Liu, W. Stillman, S. Rumyantsev, Q. Shao, M. Shur, A. A. Balandin, "Low

  16. Graphene: From Diffusive to Ultraclean-Interacting Systems

    E-Print Network [OSTI]

    Amrhein, Valentin

    Graphene: From Diffusive to Ultraclean-Interacting Systems Inauguraldissertation zur Erlangung der. Introduction 1 2. The Properties of Graphene 3 2.1. Band Structure of Graphene . . . . . . . . . . . . . . . . . . . . . 3 2.1.1. Single Layer Graphene . . . . . . . . . . . . . . . . . . . . 3 2.1.2. Bilayer Graphene

  17. Graphene and Quantum Mechanics University of California, Berkeley

    E-Print Network [OSTI]

    Zworski, Maciej

    Graphene and Quantum Mechanics Minjae Lee University of California, Berkeley lee.minjae@math.berkeley.edu March 31, 2014 Minjae Lee (UC Berkeley) Graphene March 31, 2014 1 / 9 #12;Carbon structures Graphite 3 Berkeley) Graphene March 31, 2014 2 / 9 #12;Graphene Graphene A single layer of graphite The thinnest 2D

  18. Bound States in Graphene

    E-Print Network [OSTI]

    Kumar S. Gupta; Siddhartha Sen

    2008-06-03T23:59:59.000Z

    We present a quantum analysis of the massless excitations in graphene with a charge impurity. When the effective charge exceeds a certain critical value, the spectrum is quantized and is unbounded from below. The corresponding eigenstates are square-integrable at infinity and have a rapidly oscillatory behaviour in the short distance, which can be interpreted as a fall to the centre. Using a cutoff regularization, we show that the effective Coulomb interaction strength is driven to its critical value under the renormalization group flow. In the subcritical region, we find bound states with imaginary values of the energy for certain range of the system parameters. The physical significance of these bound states with imaginary eigenvalues is discussed.

  19. Charging Graphene for Energy Storage

    SciTech Connect (OSTI)

    Liu, Jun

    2014-10-06T23:59:59.000Z

    Since 2004, graphene, including single atomic layer graphite sheet, and chemically derived graphene sheets, has captured the imagination of researchers for energy storage because of the extremely high surface area (2630 m2/g) compared to traditional activated carbon (typically below 1500 m2/g), excellent electrical conductivity, high mechanical strength, and potential for low cost manufacturing. These properties are very desirable for achieving high activity, high capacity and energy density, and fast charge and discharge. Chemically derived graphene sheets are prepared by oxidation and reduction of graphite1 and are more suitable for energy storage because they can be made in large quantities. They still contain multiply stacked graphene sheets, structural defects such as vacancies, and oxygen containing functional groups. In the literature they are also called reduced graphene oxide, or functionalized graphene sheets, but in this article they are all referred to as graphene for easy of discussion. Two important applications, batteries and electrochemical capacitors, have been widely investigated. In a battery material, the redox reaction occurs at a constant potential (voltage) and the energy is stored in the bulk. Therefore, the energy density is high (more than 100 Wh/kg), but it is difficult to rapidly charge or discharge (low power, less than 1 kW/kg)2. In an electrochemical capacitor (also called supercapacitors or ultracapacitor in the literature), the energy is stored as absorbed ionic species at the interface between the high surface area carbon and the electrolyte, and the potential is a continuous function of the state-of-charge. The charge and discharge can happen rapidly (high power, up to 10 kW/kg) but the energy density is low, less than 10 Wh/kg2. A device that can have both high energy and high power would be ideal.

  20. Highly controllable and green reduction of graphene oxide to flexible graphene film with high strength

    SciTech Connect (OSTI)

    Wan, Wubo [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Zhao, Zongbin, E-mail: zbzhao@dlut.edu.cn [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Hu, Han [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Gogotsi, Yury [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Department of Materials Science and Engineering, and A.J. Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA 19104 (United States); Qiu, Jieshan, E-mail: jqiu@dlut.edu.cn [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China)

    2013-11-15T23:59:59.000Z

    Graphical abstract: Highly controllable and green reduction of GO to chemical converted graphene (CCG) was achieved with sodium citrate as a facile reductant. Self-assembly of the as-made CCG sheets results in a flexible CCG film, of which the tensile strength strongly depends on the deoxygenation degree of graphene sheets. - Highlights: • Graphene was synthesized by an effective and environmentally friendly approach. • We introduced a facile X-ray diffraction analysis method to investigate the reduction process from graphene oxide to graphene. • Flexible graphene films were prepared by self-assembly of the graphene sheets. • The strength of the graphene films depends on the reduction degree of graphene. - Abstract: Graphene film with high strength was fabricated by the assembly of graphene sheets derived from graphene oxide (GO) in an effective and environmentally friendly approach. Highly controllable reduction of GO to chemical converted graphene (CCG) was achieved with sodium citrate as a facile reductant, in which the reduction process was monitored by XRD analysis and UV–vis absorption spectra. Self-assembly of the as-made CCG sheets results in a flexible CCG film. This method may open an avenue to the easy and scalable preparation of graphene film with high strength which has promising potentials in many fields where strong, flexible and electrically conductive films are highly demanded.

  1. Relativistic graphene ratchet on semidisk Galton board

    E-Print Network [OSTI]

    Leonardo Ermann; Dima L. Shepelyansky

    2010-11-17T23:59:59.000Z

    Using extensive Monte Carlo simulations we study numerically and analytically a photogalvanic effect, or ratchet, of directed electron transport induced by a microwave radiation on a semidisk Galton board of antidots in graphene. A comparison between usual two-dimensional electron gas (2DEG) and electrons in graphene shows that ratchet currents are comparable at very low temperatures. However, a large mean free path in graphene should allow to have a strong ratchet transport at room temperatures. Also in graphene the ratchet transport emerges even for unpolarized radiation. These properties open promising possibilities for room temperature graphene based sensitive photogalvanic detectors of microwave and terahertz radiation.

  2. Tunable Electrochemical Properties of Fluorinated Graphene

    SciTech Connect (OSTI)

    Meduri, Praveen; Chen, Honghao; Xiao, Jie; Martinez, Jayson J.; Carlson, Thomas J.; Zhang, Jiguang; Deng, Zhiqun

    2013-06-18T23:59:59.000Z

    The structural and electrochemical properties of fluorinated graphene have been investigated by using a series of graphene fluorides (CFx, x=0.47, 0.66, 0.89). Fluorinated graphene exhibited high capacity retentions of 75-81% of theoretical capacity at moderate rates as cathode materials for primary lithium batteries. Specifically, CF0.47 maintained a capacity of 356 mAhg-1 at a 5C rate, superior to that of traditional fluorinated graphite. The discharged graphene fluorides also provide an electrochemical tool to probe the chemical bonding on the parent graphene substrate.

  3. Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene/Ru(0001) Heterostructures

    E-Print Network [OSTI]

    Ciobanu, Cristian

    Graphene on Ru(0001) Moire Corrugation Studied by Scanning Tunneling Microscopy on Au/Graphene on graphene/Ru(0001) were used to study the corrugation of the moire structure of graphene/Ru(0001 for the graphene/Ru(0001) moire is of structural nature rather than electronic. STM showed a large value

  4. Graphene nanopore field effect transistors

    SciTech Connect (OSTI)

    Qiu, Wanzhi; Skafidas, Efstratios, E-mail: sskaf@unimelb.edu.au [Centre for Neural Engineering, The University of Melbourne, 203 Bouverie Street, Carlton, Victoria 3053 (Australia); Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, Victoria 3010 (Australia)

    2014-07-14T23:59:59.000Z

    Graphene holds great promise for replacing conventional Si material in field effect transistors (FETs) due to its high carrier mobility. Previously proposed graphene FETs either suffer from low ON-state current resulting from constrained channel width or require complex fabrication processes for edge-defecting or doping. Here, we propose an alternative graphene FET structure created on intrinsic metallic armchair-edged graphene nanoribbons with uniform width, where the channel region is made semiconducting by drilling a pore in the interior, and the two ends of the nanoribbon act naturally as connecting electrodes. The proposed GNP-FETs have high ON-state currents due to seamless atomic interface between the channel and electrodes and are able to be created with arbitrarily wide ribbons. In addition, the performance of GNP-FETs can be tuned by varying pore size and ribbon width. As a result, their performance and fabrication process are more predictable and controllable in comparison to schemes based on edge-defects and doping. Using first-principle transport calculations, we show that GNP-FETs can achieve competitive leakage current of ?70?pA, subthreshold swing of ?60?mV/decade, and significantly improved On/Off current ratios on the order of 10{sup 5} as compared with other forms of graphene FETs.

  5. Counting molecular-beam grown graphene layers

    SciTech Connect (OSTI)

    Plaut, Annette S. [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom)] [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Wurstbauer, Ulrich [Department of Physics, Columbia University, New York, New York 10027 (United States)] [Department of Physics, Columbia University, New York, New York 10027 (United States); Pinczuk, Aron [Department of Physics, Columbia University, New York, New York 10027 (United States) [Department of Physics, Columbia University, New York, New York 10027 (United States); Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Garcia, Jorge M. [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain)] [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain); Pfeiffer, Loren N. [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)] [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)

    2013-06-17T23:59:59.000Z

    We have used the ratio of the integrated intensity of graphene's Raman G peak to that of the silicon substrate's first-order optical phonon peak, accurately to determine the number of graphene layers across our molecular-beam (MB) grown graphene films. We find that these results agree well both, with those from our own exfoliated single and few-layer graphene flakes, and with the results of Koh et al.[ACS Nano 5, 269 (2011)]. We hence distinguish regions of single-, bi-, tri-, four-layer, etc., graphene, consecutively, as we scan coarsely across our MB-grown graphene. This is the first, but crucial, step to being able to grow, by such molecular-beam-techniques, a specified number of large-area graphene layers, to order.

  6. Diamond as an inert substrate of graphene

    SciTech Connect (OSTI)

    Hu Wei; Li Zhenyu; Yang Jinlong [Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2013-02-07T23:59:59.000Z

    Interaction between graphene and semiconducting diamond substrate has been examined with large-scale density functional theory calculations. Clean and hydrogenated diamond (100) and (111) surfaces have been studied. It turns out that weak van der Waals interactions dominate for graphene on all these surfaces. High carrier mobility of graphene is almost not affected, except for a negligible energy gap opening at the Dirac point. No charge transfer between graphene and diamond (100) surfaces is detected, while different charge-transfer complexes are formed between graphene and diamond (111) surfaces, inducing either p-type or n-type doping on graphene. Therefore, diamond can be used as an excellent substrate of graphene, which almost keeps its electronic structures at the same time providing the flexibility of charge doping.

  7. Graphene-Based Optical Biosensors and Imaging

    SciTech Connect (OSTI)

    Tang, Zhiwen; He, Shijiang; Pei, Hao; Du, Dan; Fan, Chunhai; Lin, Yuehe

    2014-01-13T23:59:59.000Z

    This chapter focuses on the design, fabrication and application of graphene based optical nanobiosensors. The emerging graphene based optical nanobiosensors demonstrated the promising bioassay and biomedical applications thanking to the unique optical features of graphene. According to the different applications, the graphene can be tailored to form either fluorescent emitter or efficient fluorescence quencher. The exceptional electronic feature of graphene makes it a powerful platform for fabricating the SPR and SERS biosensors. Today the graphene based optical biosensors have been constructed to detect various targets including ions, small biomolecules, DNA/RNA and proteins. This chapter reviews the recent progress in graphene-based optical biosensors and discusses the opportunities and challenges in this field.

  8. Gigahertz Ambipolar Frequency Multiplier Based on Cvd Graphene

    E-Print Network [OSTI]

    Wang, Han

    Ambipolar transport in graphene offers great opportunities for novel device and circuit applications. This paper discusses the RF performance of CVD grown graphene transistors for the first time. Then, a new graphene ...

  9. Klein backscattering and Fabry-Perot resonances in graphene

    E-Print Network [OSTI]

    Gabrieli, John

    Klein backscattering and Fabry- Perot resonances in graphene p-n-p junctions Leonid Levitov gap = hvF/width Coulomb blockade in graphene Geim, Novoselov; Ensslin group #12;Graphene p

  10. Tearing Graphene Sheets From Adhesive Substrates Produces Tapered Nanoribbons

    E-Print Network [OSTI]

    Entekhabi, Dara

    Thin films Tearing Graphene Sheets From Adhesive Substrates Produces Tapered Nanoribbons Dipanjan Sen, Kostya S. Novoselov, Pedro M. Reis, and Markus J. Buehler* Graphene is a truly two- film materials have been studied extensively, the key mechanical properties of graphene

  11. Graphene Growth by Metal Etching on Ru (0001)

    E-Print Network [OSTI]

    Loginova, Elena

    2010-01-01T23:59:59.000Z

    of step etching during graphene growth, such as in Fig. 3,adsorption of water on graphene structures will be describedRu(0001) Figure 5. a b c graphene Ru d Figure 6. Figure 7. a

  12. Graphene Layer Growth Chemistry: Five-Six-Ring Flip Reaction

    E-Print Network [OSTI]

    Whitesides, R.; Domin, D.; Salomon-Ferrer, R.; Lester Jr., W.A.; Frenklach, M.

    2008-01-01T23:59:59.000Z

    are incorporated into growing graphene layers and hence willGRAPHENE LAYER GROWTH CHEMISTRY: FIVE-SIX-RING FLIP REACTIONon the zigzag edge of a graphene layer. A new reaction

  13. Graphene Layer Growth Chemistry: Five-Six-Ring Flip Reaction

    E-Print Network [OSTI]

    Whitesides, Russell; Domin, Dominik; Lester Jr., William A.; Frenklach, Michael

    2007-01-01T23:59:59.000Z

    25-28, 2007. Topic: Soot GRAPHENE LAYER GROWTH CHEMISTRY:on the zigzag edge of a graphene layer isomerizes to reversea possibly important step in graphene layer growth, thus

  14. Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Wednesday, 29 October 2008 00:00 Graphene-a single layer...

  15. Graphene growth with giant domains using chemical vapor deposition

    E-Print Network [OSTI]

    Yong, Virginia; Hahn, H. Thomas

    2011-01-01T23:59:59.000Z

    N. Martensson, Controlling graphene corrugation on lattice-in patterned epitaxial graphene, Science, 2006, 312(5777), 92009, 4(6), 17 A. K. Geim, Graphene: Status and Prospects,

  16. Substrate-induced band gap opening in epitaxial graphene

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    H.A. Electronic states of graphene nanoribbons studied withS.G. Louie. Energy gaps in graphene nanoribbons. Phys. Rev.band-gap engineering of graphene nanoribbons. Phys. Rev.

  17. Many-body interactions in quasi-freestanding graphene

    E-Print Network [OSTI]

    Siegel, David

    2012-01-01T23:59:59.000Z

    ects in doped and undoped graphene: Fermi liquid versus non-GW many-body ef- fects in graphene. Phys. Rev. Lett. 101:the spectral func- tion of graphene. Phys. Rev. B 77:081411(

  18. Self-doping effects in epitaxially grown graphene

    E-Print Network [OSTI]

    Siegel, David A.

    2009-01-01T23:59:59.000Z

    The electronic properties of graphene, Rev. Mod. Phys. (inE?ects in Epitaxially-Grown Graphene D.A. Siegel, 1, 2 S.Y.2009) Abstract Self-doping in graphene has been studied by

  19. The Schwinger mechanism and graphene

    E-Print Network [OSTI]

    Danielle Allor; Thomas D. Cohen; David A. McGady

    2008-09-22T23:59:59.000Z

    The Schwinger mechanism, the production of charged particle-antiparticle pairs in a macroscopic external electric field, is derived for 2+1 dimensional theories. The rate of pair production per unit area for four species of massless fermions, with charge $q$, in a constant electric field $E$ is given by $ \\pi^{-2} \\hbar^{-3/2} \\tilde{c}^{-1/2} (q E)^{3/2} $ where $\\tilde{c}$ is the speed of light for the two-dimensional system. To the extent undoped graphene behaves like the quantum field-theoretic vacuum for massless fermions in 2+1 dimensions, the Schwinger mechanism should be testable experimentally. A possible experimental configuration for this is proposed. Effects due to deviations from this idealized picture of graphene are briefly considered. It is argued that with present day samples of graphene, tests of the Schwinger formula may be possible.

  20. A supersymmetric model for graphene

    E-Print Network [OSTI]

    Everton M. C. Abreu; Marco A. De Andrade; Leonardo P. G. de Assis; Jose A. Helayel-Neto; A. L. M. A. Nogueira; Ricardo C. Paschoal

    2014-07-21T23:59:59.000Z

    In this work, we focus on the fermionic structure of the low-energy excitations of graphene (a monolayer of carbon atoms) to propose a new supersymmetric field-theoretic model for this physical system. In the current literature, other proposals for describing graphene physics have been contemplated at the level of supersymmetric quantum mechanics. Also, by observing the inhomogeneities between neighbor carbon atoms, Jackiw {\\it et al.} have set up an interesting chiral Abelian gauge theory. We show in this paper that our formulation encompasses models discussed previously as sectors of an actually richer (supersymmetric) planar gauge model. Possible interpretations for the fields involved in the present graphene model are proposed and the question of supersymmetry breaking is discussed.

  1. Electron Effective Mass in Graphene

    E-Print Network [OSTI]

    Viktor Ariel; Amir Natan

    2012-08-12T23:59:59.000Z

    The particle effective mass in graphene is a challenging concept because the commonly used theoretical expression is mathematically divergent. In this paper, we use basic principles to present a simple theoretical expression for the effective mass that is suitable for both parabolic and non-parabolic isotropic materials. We demonstrate that this definition is consistent with the definition of the cyclotron effective mass, which is one of the common methods for effective mass measurement in solid state materials. We apply the proposed theoretical definition to graphene and demonstrate linear dependence of the effective mass on momentum, as confirmed by experimental cyclotron resonance measurements. Therefore, the proposed definition of the effective mass can be used for non-parabolic materials such as graphene.

  2. Physisorption of Nucleobases on Graphene

    E-Print Network [OSTI]

    S. Gowtham; Ralph H. Scheicher; Rajeev Ahuja; Ravindra Pandey; Shashi P. Karna

    2007-04-11T23:59:59.000Z

    We report the results of our first-principles investigation on the interaction of the nucleobases adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U) with graphene, carried out within the density functional theory framework, with additional calculations utilizing Hartree--Fock plus second-order Moeller-Plesset perturbation theory. The calculated binding energy of the nucleobases shows the following hierarchy: G > T ~ C ~ A > U, with the equilibrium configuration being very similar for all five of them. Our results clearly demonstrate that the nucleobases exhibit significantly different interaction strengths when physisorbed on graphene. The stabilizing factor in the interaction between the base molecule and graphene sheet is dominated by the molecular polarizability that allows a weakly attractive dispersion force to be induced between them. The present study represents a significant step towards a first-principles understanding of how the base sequence of DNA can affect its interaction with carbon nanotubes, as observed experimentally.

  3. Long Island Solar Farm

    SciTech Connect (OSTI)

    Anders, R.

    2013-05-01T23:59:59.000Z

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  4. Soil Landscape Assessment atSoil Landscape Assessment at D I l d L A C d KD I l d L A C d KDog Island Lease Area, Cedar KeyDog Island Lease Area, Cedar Key

    E-Print Network [OSTI]

    Florida, University of

    Soil Landscape Assessment atSoil Landscape Assessment at D I l d L A C d KD I l d L A C d KDog Island Lease Area, Cedar KeyDog Island Lease Area, Cedar Key #12;Soil SampleSoil Sample LocationsLocationsLocationsLocations #12;Soil ElevationSoil Elevation (Bathymetry)(Bathymetry)(Bathymetry)(Bathymetry) 1.5 ft NAD881.5 ft

  5. Improved Electrical Conductivity of Graphene Films Integrated with Metal Nanowires

    E-Print Network [OSTI]

    tin oxide films in electrochromic (EC) devices. The successful integration of such graphene/NW films. KEYWORDS: Graphene, nanowires, transparent conductive films, electrochromic devices Due to low electron

  6. Graphene Device Fabrication and Applications in Communication Systems.

    E-Print Network [OSTI]

    Liu, Guanxiong

    2012-01-01T23:59:59.000Z

    ??High carrier mobility, saturation velocity and thermal conductivity make graphene a promising material for high-frequency, analog and communication applications. The ambipolar properties of graphene provide… (more)

  7. ORNL-led team demonstrates desalination with nanoporous graphene...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Communications 865.576.6448 ORNL-led team demonstrates desalination with nanoporous graphene membrane Researchers created nanopores in graphene (red, and enlarged in the circle...

  8. A graphene-based electrochemical sensor for sensitive detection...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A graphene-based electrochemical sensor for sensitive detection of paracetamol . A graphene-based electrochemical sensor for sensitive detection of paracetamol . Abstract: An...

  9. Nitrogen-doped Graphene and Its Electrochemical Applications

    SciTech Connect (OSTI)

    Shao, Yuyan; Zhang, Sheng; Engelhard, Mark H.; Li, Guosheng; Shao, Guocheng; Wang, Yong; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2010-06-04T23:59:59.000Z

    Nitrogen-doped graphene (N-graphene) is obtained by exposing graphene to nitrogen plasma. N-graphene exhibits much higher electrocatalytic activity toward oxygen reduction and H2O2 reduction than graphene, and much higher durability and selectivity than the widely-used expensive Pt. The excellent electrochemical performance of N-graphene is attributed to nitrogen functional groups and the specific properties of graphene. This indicates that N-graphene is promising for applications in electrochemical energy devices (fuel cells, metal-air batteries) and biosensors.

  10. Crown Ethers in Graphene Bring Strong, Selective Binding | ornl...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Materials Characterization Crown Ethers in Graphene Bring Strong, Selective Binding November 14, 2014 Schematic showing a graphene sheet containing an array of ideal crown ethers....

  11. Elucidating graphene - Ionic Liquid interfacial region: a combined...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    graphene - Ionic Liquid interfacial region: a combined experimental and computational study. Elucidating graphene - Ionic Liquid interfacial region: a combined experimental and...

  12. Constraint of DNA on Functionalized Graphene Improves Its Biostability...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Constraint of DNA on Functionalized Graphene Improves Its Biostability and Specificity. Constraint of DNA on Functionalized Graphene Improves Its Biostability and Specificity....

  13. Modification of Defect Structures in Graphene by Electron Irradiation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations. Modification of Defect Structures in Graphene by Electron...

  14. Glucose oxidase-graphene-chitosan modified electrode for direct...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    oxidase-graphene-chitosan modified electrode for direct electrochemistry and glucose sensing. Glucose oxidase-graphene-chitosan modified electrode for direct electrochemistry and...

  15. A Prototype for Graphene Material Simulation: Structures and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Prototype for Graphene Material Simulation: Structures and Interaction Potentials ofCoronene Dimers. A Prototype for Graphene Material Simulation: Structures and Interaction...

  16. Graphene Produces More Efficient Charge Transport Inside an Organic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Graphene Produces More Efficient Charge Transport Inside an Organic Semiconductor Graphene, a two dimensional semi-metal made of sp 2 hybridized carbon, is an outstanding material...

  17. Graphene-Polypyrrole Nanocomposite as a Highly Efficient and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Graphene-Polypyrrole Nanocomposite as a Highly Efficient and Low Cost Electrically Switched Ion Exchanger for Removing ClO4- Graphene-Polypyrrole Nanocomposite as a Highly...

  18. Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal Transition and Remarkable Large Magnetism. Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal Transition...

  19. Novel Electronic and Magnetic Properties of Graphene Nanoflakes...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Electronic and Magnetic Properties of Graphene Nanoflakes in a Boron Nitride Layer. Novel Electronic and Magnetic Properties of Graphene Nanoflakes in a Boron Nitride Layer....

  20. Crown Ethers Flatten in Graphene for Strong, Specific Binding...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    SHARE Crown Ethers Flatten in Graphene for Strong, Specific Binding ORNL discovery holds potential for separations, sensors, batteries, biotech and more This sheet of graphene...

  1. Graphene Produces More Efficient Charge Transport Inside an Organic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Graphene Produces More Efficient Charge Transport Inside an Organic Semiconductor Friday, January 30, 2015 Graphene, a two dimensional semi-metal made of sp2 hybridized carbon, is...

  2. Functionalized Graphene Sheets as Molecular Templates for Controlled...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    as Molecular Templates for Controlled Nucleation and Self-Assembly of Metal Oxide-Graphene Functionalized Graphene Sheets as Molecular Templates for Controlled Nucleation and...

  3. Flexible Pillared Graphene-Paper Electrodes for High-Performance...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Flexible Pillared Graphene-Paper Electrodes for High-Performance Electrochemical Supercapacitors. Flexible Pillared Graphene-Paper Electrodes for High-Performance Electrochemical...

  4. A graphene-based electrochemical sensor for sensitive detection...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    graphene-based electrochemical sensor for sensitive detection of paracetamol . A graphene-based electrochemical sensor for sensitive detection of paracetamol . Abstract: An...

  5. Nitrogen-Doped Graphene and its Application in Electrochemical...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Doped Graphene and its Application in Electrochemical Biosensing. Nitrogen-Doped Graphene and its Application in Electrochemical Biosensing. Abstract: Chemical doping with foreign...

  6. Strain Effects on Electrical Properties of Suspended Graphene.

    E-Print Network [OSTI]

    Smith, Anderson David

    2011-01-01T23:59:59.000Z

    ?? Graphene is an extraordinary material which shows tremendous potential as a replacement for silicon in many electronic applications. However, one major drawback to graphene… (more)

  7. Utility Scale Wind Turbines on a Grid Connected Island Mohit Dua, Anthony L. Rogers, James F. Manwell,

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Utility Scale Wind Turbines on a Grid Connected Island Mohit Dua, Anthony L. Rogers, James F utility scale wind turbines on Fox Islands, located 12 miles from the coast of Maine in the United States of electricity itself. Three locations are analyzed in detail as potential sites for wind turbine installations

  8. Synthesis and characterizations of graphene oxide and reduced graphene oxide nanosheets

    SciTech Connect (OSTI)

    Venkanna, M., E-mail: venkanna.pcu@gmail.com; Chakraborty, Amit K., E-mail: venkanna.pcu@gmail.com [Carbon Nanotechnology Laboratory, Department of Physics, National Institute of Technology Durgapur, M.G. Avenue, Durgapur - 713209 (India)

    2014-04-24T23:59:59.000Z

    Interest in graphene on its excellent mechanical, electrical, thermal and optical properties, it’s very high specific surface area, and our ability to influence these properties through chemical functionalization. Chemical reduction of graphene oxide is one of the main routes of preparation for large quantities of graphenes. Hydrazine hydrate used as reducing agent to prepare for the reduced graphene oxide (RGO). There are a number of methods for generating graphene and chemically modified graphene from natural graphite flakes, graphite derivative (such as graphite oxide) and graphite interaction compounds (i.e. expandable graphite). Here we review the use of colloidal suspensions of reduced graphene oxide (RGO) with large scalable, and is adaptable to a wide variety of applications. The graphene oxide (GO) and the reduced material (RGO) were characterized by XRD, UV-Vis spectroscopy, Thermo-gravimetric analysis (TGA), Raman spectroscopy and Field emission Scanning electron microscopy (FESEM) etc.

  9. GREEN HOMES LONG ISLAND

    E-Print Network [OSTI]

    Kammen, Daniel M.

    energy bill, reduce your carbon footprint... at little or no cost to you. #12;A Message From Supervisor energy-efficient and reduce our community's carbon footprint. Why do we call it Long Island Green Homes to yourevery day. By making basic improvements to yourevery day home, you can reduce your carbon footprint

  10. Probing the electronic structure and optical response of a graphene quantum disk supported on monolayer graphene

    E-Print Network [OSTI]

    Pennycook, Steve

    Probing the electronic structure and optical response of a graphene quantum disk supported on monolayer graphene This article has been downloaded from IOPscience. Please scroll down to see the full text.1088/0953-8984/24/31/314213 Probing the electronic structure and optical response of a graphene quantum disk supported on monolayer

  11. Tunneling characteristics in chemical vapor deposited graphene hexagonal boron nitride graphene junctions

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Tunneling characteristics in chemical vapor deposited graphene ­ hexagonal boron nitride ­ graphene junctions T. Roy1 , L. Liu2 , S. de la Barrera,3 B. Chakrabarti1,4 , Z. R. Hesabi1 , C. A. Joiner1 Abstract: Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate

  12. GrapheneGraphene MaterialsMaterials RodRod RuoffRuoff

    E-Print Network [OSTI]

    strength; wind turbine blades; flywheel; aerospace; transportation; high power transmission lines; manyGrapheneGraphene MaterialsMaterials RodRod RuoffRuoff The University of Texas at Austin Energy, Inc., Graphene Materials LLC., and prior s pport from NASA and AFOSR DURIP is appreciated Rod

  13. Graphene tests of Klein phenomena

    E-Print Network [OSTI]

    Stefano De Leo; Pietro Rotelli

    2012-02-07T23:59:59.000Z

    Graphene is characterized by chiral electronic excitations. As such it provides a perfect testing ground for the production of Klein pairs (electron/holes). If confirmed, the standard results for barrier phenomena must be reconsidered with, as a byproduct, the accumulation within the barrier of holes.

  14. Graphene-based tunable hyperbolic metamaterials and enhanced near-field absorption.

    E-Print Network [OSTI]

    Othman, Mohamed A K; Guclu, Caner; Capolino, Filippo

    2013-01-01T23:59:59.000Z

    and M. Hanbucken, “A graphene electron lens,” Appl. Phys.based on plasmonic resonant graphene sheets,” J. Appl. Phys.polaritons in monolayer graphene sheet arrays,” Phys. Rev.

  15. Epitaxial graphene films on SiC: growth, characterization, and devices.

    E-Print Network [OSTI]

    Li, Xuebin

    2008-01-01T23:59:59.000Z

    ??Graphene is a single sheet of graphite. While bulk graphite is semimetal, graphene is a zero bandgap semiconductor. Band structure calculations show graphene has a… (more)

  16. Country Location AFGHANISTAN

    E-Print Network [OSTI]

    /01 12/31 $131 AUSTRALIA CANBERRA 01/01 12/31 $136 AUSTRALIA DARWIN, NORTHERN TERRITORY 04/01 09/30 $142 ARMENIA [OTHER] 01/01 12/31 $92 ASCENSION ISLAND ASCENSION ISLAND 01/01 12/31 $22 AUSTRALIA ADELAIDE 01/01 12/31 $157 AUSTRALIA BRISBANE 01/01 12/31 $128 AUSTRALIA BROOME 01/01 12/31 $137 AUSTRALIA CAIRNS 01

  17. Electrostatic force assisted deposition of graphene

    DOE Patents [OSTI]

    Liang, Xiaogan (Berkeley, CA)

    2011-11-15T23:59:59.000Z

    An embodiment of a method of depositing graphene includes bringing a stamp into contact with a substrate over a contact area. The stamp has at least a few layers of the graphene covering the contact area. An electric field is developed over the contact area. The stamp is removed from the vicinity of the substrate which leaves at least a layer of the graphene substantially covering the contact area.

  18. Field-induced confined states in graphene

    SciTech Connect (OSTI)

    Moriyama, Satoshi, E-mail: MORIYAMA.Satoshi@nims.go.jp [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Morita, Yoshifumi [Faculty of Engineering, Gunma University, Kiryu, Gunma 376-8515 (Japan); Watanabe, Eiichiro; Tsuya, Daiju [Nanotechnology Innovation Station, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2014-02-03T23:59:59.000Z

    We report an approach to confine the carriers in single-layer graphene, which leads to quantum devices with field-induced quantum confinement. We demonstrated that the Coulomb-blockade effect evolves under a uniform magnetic field perpendicular to the graphene device. Our experimental results show that field-induced quantum dots are realized in graphene, and a quantum confinement-deconfinement transition is switched by the magnetic field.

  19. How Bilayer Graphene Got a Bandgap

    ScienceCinema (OSTI)

    Feng Wang

    2010-01-08T23:59:59.000Z

    Graphene is the two-dimensional crystalline form of carbon, whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But theres a catch: graphene has no bandgap. Now Feng Wang and his colleagues at Berkeley Lab and UC Berkeley have engineered a bandgap in bilayer graphene that can be precisely controlled from 0 to 250 milli-electron volts, which is the energy of infrared radiation.

  20. How Bilayer Graphene Got a Bandgap

    ScienceCinema (OSTI)

    Wang, Feng

    2013-05-29T23:59:59.000Z

    Graphene is the two-dimensional crystalline form of carbon, whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But theres a catch: graphene has no bandgap. Now Feng Wang and his colleagues at Berkeley Lab and UC Berkeley have engineered a bandgap in bilayer graphene that can be precisely controlled from 0 to 250 milli-electron volts, which is the energy of infrared radiation.

  1. Chemistry at the Dirac Point of Graphene.

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01T23:59:59.000Z

    ??Graphene holds great potential as an electronic material because of its excellent transport properties, which derive from its unique Fermi surface and ballistic conductance. It… (more)

  2. Electronic and Spintronic Properties of Graphene.

    E-Print Network [OSTI]

    Pi, Keyu

    2010-01-01T23:59:59.000Z

    ??In this thesis, I summarize our studies investigating the electronic properties and spintronic properties of transition metal doped graphene over the last six years. In… (more)

  3. Tunable Dirac Magneto-Plasmons in Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and may allow much faster transmission of information than conventional electronics. Graphene is emerging as a very promising plasmonic material because its plasmonic frequency is...

  4. Electronic and Spintronic Properties of Graphene

    E-Print Network [OSTI]

    Pi, Keyu

    2010-01-01T23:59:59.000Z

    chapters. For our devices, we exfoliate graphene from highlyfinal device in Figure 2.4. Exfoliate gr raphene ont to Si/

  5. Graphene: A New Era of Technology

    E-Print Network [OSTI]

    Ankita Dixit; Divya Dixit; Vidhi Vart Ch; Ashok Kajla

    Abstract — The aim of this literature indicate that graphene composites are promising multifunctional materials with improved tensile strength and elastic modulus, mechanical strength, optical property, electrical and thermal conductivity. Its unique quality light weight, high strength, excellent electric conductivity makes it differ from any other material. It has ability to replace the silicon and change the scenario of semiconductor devices. It is a base of nano technology. Due to its unique properties, it will sets the new dimension in the nano techno world. Keywords — Molybdenum-disulphide (MoS 2), chemically reduced graphene oxide (CRGO), indium tin oxide (ITO), graphene oxide (GO), thermally reduce graphene oxide (TRGO) I.

  6. Molecular architecture and functionalization of graphene surface...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Molecular architecture and functionalization of graphene surface; Synthesis and characterization Wednesday, November 12, 2014 - 3:00pm SLAC, Redtail Hawk Conference Room 108A...

  7. Control of Superhydrophilic and Superhydrophobic Graphene Interface

    E-Print Network [OSTI]

    Gao, Hongjun

    in many applications, such as waterproof surfaces, anti-contam- ination surfaces, coatings and biomedical characteristics of graphene were obtained through chemical modification of Graphite Oxide (GO), aerogels

  8. Controlled synthesis of single-crystalline graphene

    SciTech Connect (OSTI)

    Xueshen, Wang, E-mail: wangxs@nim.ac.cn; Jinjin, Li, E-mail: jinjinli@nim.ac.cn; Qing, Zhong; Yuan, Zhong; Mengke, Zhao; Yonggang, Liu [National Institute of Metrology, Beijing, China, 100013 (China)] [National Institute of Metrology, Beijing, China, 100013 (China)

    2014-03-15T23:59:59.000Z

    This paper reports the controlled synthesis of single-crystalline graphene on the back side of copper foil using CH{sub 4} as the precursor. The influence of growth time and the pressure ratio of CH{sub 4}/H{sub 2} on the structure of graphene are examined. An optimized polymer-assisted method is used to transfer the synthesized graphene onto a SiO{sub 2}/Si substrate. Scanning electron microscopy and Raman spectroscopy are used to characterize the graphene.

  9. Preparation and characterization of solar exfoliated graphene

    SciTech Connect (OSTI)

    M, Sreejesh, E-mail: sreejeshmnasc@gmail.com; S, Nagaraja H., E-mail: hosakoppa@gmail.com [Materials Research Laboratory, Department of Physics, National Institute of Technology Karnataka Surathkal, Mangalore-575025 (India); K, Udaya Bhat, E-mail: udayabhatk@gmail.com [Department of Metallurgical and Materials Engineering, National Institute of Karnataka Surathkal, Mangalore-575 025 (India)

    2014-10-15T23:59:59.000Z

    Hummer's method was used for the chemical synthesis of graphite oxide from graphite flakes. Simultaneous exfoliation and reduction of graphite oxide to Graphene was achieved through focused solar light irradiation using a convex lens. The morphological characteristics were studied using SEM and TEM. Layered morphology of Graphene was observed through TEM. Raman spectra and FTIR were used for the structural characterization of Graphene. EDAX analysis showed the drop in oxygen content during exfoliation. The method offered a faster, easier and environmental friendly method to produce Graphene for potential applications.

  10. Electrical and Thermoelectrical Transport Properties of Graphene.

    E-Print Network [OSTI]

    Wang, Deqi

    2011-01-01T23:59:59.000Z

    ??Graphene is a newly discovered material. It has many excellent properties, which make the research of this new material very important not only for the… (more)

  11. Tunneling characteristics in chemical vapor deposited graphene–hexagonal boron nitride–graphene junctions

    SciTech Connect (OSTI)

    Roy, T.; Hesabi, Z. R.; Joiner, C. A.; Vogel, E. M. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Liu, L.; Gu, G. [Department of Electrical Engineering and Computer Science, University of Tennessee, 1520 Middle Drive, Knoxville, Tennessee 37996 (United States); Barrera, S. de la; Feenstra, R. M. [Department of Physics, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213 (United States); Chakrabarti, B. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Department of Materials Science and Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080 (United States)

    2014-03-24T23:59:59.000Z

    Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate graphene–hexagonal boron nitride–graphene symmetric field effect transistors. Gate control of the tunneling characteristics is observed similar to previously reported results for exfoliated graphene–hexagonal boron nitride–graphene devices. Density-of-states features are observed in the tunneling characteristics of the devices, although without large resonant peaks that would arise from lateral momentum conservation. The lack of distinct resonant behavior is attributed to disorder in the devices, and a possible source of the disorder is discussed.

  12. Early Migratory Behavior of Northern Fur Seal (Callorhinus ursinus) Pups from Bering Island, Russia

    E-Print Network [OSTI]

    Lee, Olivia Astillero

    2012-07-16T23:59:59.000Z

    examined the early migratory behavior and habitat associations of pups from Bering Island (BI), Russia. I instrumented 35 pups with Mk10-AL satellite tags and stomach temperature telemeters which provided diving, foraging and location data. I hypothesized...

  13. U.S. Virgin Islands Ramping Up Clean Energy Efforts with an Eye...

    Broader source: Energy.gov (indexed) [DOE]

    Renewable energy technologies, such as the 5 MW Estate Donor Solar Project located on St. Thomas, have helped the U.S. Virgin Islands reduce its fossil fuel use by 20% over the...

  14. Size-dependent mobility of gold nano-clusters during growth on chemically modified graphene

    SciTech Connect (OSTI)

    Bell, Gavin R., E-mail: gavin.bell@warwick.ac.uk; Dawson, Peter M.; Pandey, Priyanka A.; Wilson, Neil R. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Mulheran, Paul A. [Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose St., Glasgow G1 1XJ (United Kingdom)

    2014-01-01T23:59:59.000Z

    Gold nano-clusters were grown on chemically modified graphene by direct sputter deposition. Transmission electron microscopy of the nano-clusters on these electron-transparent substrates reveals an unusual bimodal island size distribution (ISD). A kinetic Monte Carlo model of growth incorporating a size-dependent cluster mobility rule uniquely reproduces the bimodal ISD, providing strong evidence for the mobility of large clusters during surface growth. The cluster mobility exponent of ?5/3 is consistent with cluster motion via one-dimensional diffusion of gold atoms around the edges of the nano-clusters.

  15. Transfer matrix theory of monolayer graphene/bilayer graphene heterostructure superlattice

    SciTech Connect (OSTI)

    Wang, Yu, E-mail: ywang@semi.ac.cn [Department of Physics, Faculty of Science, Kunming University of Science and Technology, Kunming 650500 (China)

    2014-10-28T23:59:59.000Z

    We have formulated a transfer matrix method to investigate electronic properties of graphene heterostructure consisting of monolayer graphene and bilayer counterpart. By evaluating transmission, conductance, and band dispersion, we show that, irrespective of the different carrier chiralities in monolayer graphene and bilayer graphene, superlattice consisting of biased bilayer graphene barrier and monolayer graphene well can mimic the electronic properties of conventional semiconductor superlattice, displaying the extended subbands in the quantum tunneling regime and producing anisotropic minigaps for the classically allowed transport. Due to the lateral confinement, the lowest mode has shifted away from the charge neutral point of monolayer graphene component, opening a sizeable gap in concerned structure. Following the gate-field and geometry modulation, all electronic states and gaps between them can be externally engineered in an electric-controllable strategy.

  16. Amchitka Island, Alaska, Biological Monitoring Report 2011 Sampling Results

    SciTech Connect (OSTI)

    None

    2013-09-01T23:59:59.000Z

    The Long-Term Surveillance and Maintenance (LTS&M) Plan for the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Amchitka Island sites describes how LM plans to conduct its mission to protect human health and the environment at the three nuclear test sites located on Amchitka Island, Alaska. Amchitka Island, near the western end of the Aleutian Islands, is approximately 1,340 miles west-southwest of Anchorage, Alaska. Amchitka is part of the Aleutian Island Unit of the Alaska Maritime National Wildlife Refuge, which is administered by the U.S. Fish and Wildlife Service (USFWS). Since World War II, Amchitka has been used by multiple U.S. government agencies for various military and research activities. From 1943 to 1950, it was used as a forward air base for the U.S. Armed Forces. During the middle 1960s and early 1970s, the U.S. Department of Defense (DOD) and the U.S. Atomic Energy Commission (AEC) used a portion of the island as a site for underground nuclear tests. During the late 1980s and early 1990s, the U.S. Navy constructed and operated a radar station on the island. Three underground nuclear tests were conducted on Amchitka Island. DOD, in conjunction with AEC, conducted the first nuclear test (named Long Shot) in 1965 to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC in 1969 as a means to study the feasibility of detonating a much larger device. Cannikin, the third nuclear test on Amchitka, was a weapons-related test detonated on November 6, 1971. With the exception of small concentrations of tritium detected in surface water shortly after the Long Shot test, radioactive fission products from the tests remain in the subsurface at each test location As a continuation of the environmental monitoring that has taken place on Amchitka Island since before 1965, LM in the summer of 2011 collected biological and seawater samples from the marine and terrestrial environment of Amchitka Island adjacent to the three detonation sites and at a background or reference site, Adak Island, 180 miles to the east. Consistent with the goals of the Amchitka LTS&M Plan, four data quality objectives (DQOs) were developed for the 2011 sampling event.

  17. Substrate-Free Gas-Phase Synthesis of Graphene Sheets

    E-Print Network [OSTI]

    Frenklach, Michael

    Substrate-Free Gas-Phase Synthesis of Graphene Sheets Albert Dato,*, Velimir Radmilovic, Zonghoon graphene sheets in the gas phase using a substrate-free, atmospheric-pressure microwave plasma reactor. Graphene sheets were synthesized by passing liquid ethanol droplets into an argon plasma. The graphene

  18. Covalent Functionalization of Epitaxial Graphene by Azidotrimethylsilane Junghun Choi,

    E-Print Network [OSTI]

    Kim, Sehun

    Covalent Functionalization of Epitaxial Graphene by Azidotrimethylsilane Junghun Choi, Ki-jeong Kim, 2009 Chemically modified epitaxial graphene (EG) by azidotrimethylsilane (ATS) was investigated using graphene (CSG) model, we elucidated that nitrene radicals adsorb on the graphene layer at two different

  19. A photothermoelectric effect in graphene D. M. Basko

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A photothermoelectric effect in graphene D. M. Basko Universit´e Grenoble 1/CNRS, LPMMC UMR 5493, B they used was graphene. So, does it mean that graphene violates the laws of physics that we have read about. The key idea of the experiment is to take a single sheet of graphene, but to place two regions of it under

  20. Thermal Transport in Suspended and Supported Monolayer Graphene Grown by

    E-Print Network [OSTI]

    interface resistance, graphene, Raman, measurement S ince graphene was exfoliated from graphite in 2004 it is difficult to utilize mechanically exfoliated, small graphene flakes for mass production of functional 15000 cm2 V-1 s-1 found in mechanically exfoliated graphene supported on SiO2 at room temperature.1

  1. Probing the Intrinsic Properties of Exfoliated Graphene: Raman

    E-Print Network [OSTI]

    Heinz, Tony F.

    Probing the Intrinsic Properties of Exfoliated Graphene: Raman Spectroscopy of Free-standing graphene monolayers prepared by mechanical exfoliation of graphite are investigated. The graphene,7 or to solubilize macroscopic quantities of graphene,8 mechanical exfoliation of graphite9 currently remains

  2. hal00276997, Raman spectra of misoriented bilayer graphene

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    hal­00276997, version 1 ­ 5 May 2008 Raman spectra of misoriented bilayer graphene P. Poncharal 1 spectra from single layer graphene with a bilayer in which the two layers are arbitrarily misoriented to the similarity of the electronic structures of single layer graphene and misoriented bilayer graphene. Another

  3. Flexible Graphene Field-Effect Transistors for Microwave Electronics

    E-Print Network [OSTI]

    Shepard, Kenneth

    Flexible Graphene Field-Effect Transistors for Microwave Electronics Inanc Meric , Nicholas Petrone-frequency characteristics of graphene field-effect transistors (GFETs) has received significant interest due the very high carrier velocities in graphene. In addition to excellent electronic performance, graphene possesses

  4. Crumpled graphene: Conductive inks made by startup company Vorbeck

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    Crumpled graphene: Conductive inks made by startup company Vorbeck Materials contain crumpled graphene. This atomic-force microscope image is colorized to show the topography of a piece of graphene Technology Review in English | en Español | auf Deutsch | in Italiano | Bringing Graphene to Market

  5. Electronic Properties of Graphene 8-9 October 2010

    E-Print Network [OSTI]

    Petta, Jason

    Electronic Properties of Graphene 8-9 October 2010 The program will focus on the properties of graphene, a single-atom-thick layer of carbon. Discovered in 2004, graphene has quickly become one as the potential it offers to future nano-electronics applications. Originally, the interest in graphene

  6. Graphene as a subnanometre trans-electrode , W. Hubbard2

    E-Print Network [OSTI]

    Golovchenko, Jene A.

    #12;LETTERS Graphene as a subnanometre trans-electrode membrane S. Garaj1 , W. Hubbard2 , A. Reina3 of graphite, called graphene, have recently been the subject of intense research with the hope that practical and elec- trical sensitivity of graphene motivated us to investigate the poten- tial use of graphene

  7. Gilbert M. Smith, master boatbuilder of Long Island, New York

    E-Print Network [OSTI]

    Merwin, Daria Elizabeth

    2000-01-01T23:59:59.000Z

    The second half of the 19th century in maritime America was an era marked by a rich variety of vernacular watercraft types adapted to a wide range of local needs and traditions. The Great South Bay, located off Long Island, New York, was home...

  8. Culturing revolution : the local Communists of China's Hainan Island

    E-Print Network [OSTI]

    Murray, Jeremy Andrew

    2011-01-01T23:59:59.000Z

    One: Deserted Treasure Island……………………………………………….13 ChapterChapter One Deserted Treasure Island: The Social Ecology andIsolated Island/Treasure Island – Gudao / Baodao Social and

  9. Rhode Island Stormwater Design and Installation Standards Manual (Rhode Island)

    Broader source: Energy.gov [DOE]

    Rhode Island's stormwater design and installation standards manual has been developed to describe mandatory and suggested stormwater design and performance criteria for applicants to the Department...

  10. How Graphene Slides: Measurement and Theory of Strain-Dependent Frictional Forces between Graphene and SiO2

    E-Print Network [OSTI]

    How Graphene Slides: Measurement and Theory of Strain- Dependent Frictional Forces between Graphene, and adhesion are interwoven in determining how graphene responds when pulled across a substrate. Using Raman spectroscopy of circular, graphene-sealed microchambers under variable external pressure, we demonstrate

  11. Study of Thermal Properties of Graphene-Based Structures Using the Force Constant Method

    E-Print Network [OSTI]

    Study of Thermal Properties of Graphene-Based Structures Using the Force Constant Method Hossein, 2012) Abstract The thermal properties of graphene-based materials are theoretically investigated transport is investigated for different structures including graphene, graphene antidot lat- tices

  12. NANO EXPRESS A Study on Field Emission Characteristics of Planar Graphene

    E-Print Network [OSTI]

    Yang, Eui-Hyeok

    NANO EXPRESS A Study on Field Emission Characteristics of Planar Graphene Layers Obtained from on field emission characteristics of individual graphene layers for vacuum nanoelectronics. Graphene layers enabled electric con- nection with the graphene layers without postfabrication. The maximum emitted

  13. Chiral Symmetry Breaking in Graphene

    E-Print Network [OSTI]

    Gordon W. Semenoff

    2011-08-19T23:59:59.000Z

    The question of whether the Coulomb interaction is strong enough to break the sublattice symmetry of un-doped graphene is discussed. We formulate a strong coupling expansion where the ground state of the Coulomb Hamiltonian is found exactly and the kinetic hopping Hamiltonian is treated as a perturbation. We argue that many of the properties of the resulting system would be shared by graphene with a Hubbard model interaction. In particular, the best candidate sublattice symmetry breaking ground state is an antiferromagnetic Mott insulator. We discuss the results of some numerical simulations which indicate that the Coulomb interaction is indeed subcritical. We also point out the curious fact that, if the electron did not have spin degeneracy, the tendency to break chiral symmetry would be much greater and even relatively weak Coulomb interactions would likely gap the spectrum.

  14. Smooth electron waveguides in graphene

    E-Print Network [OSTI]

    R. R. Hartmann; N. J. Robinson; M. E. Portnoi

    2010-06-29T23:59:59.000Z

    We present exact analytical solutions for the zero-energy modes of two-dimensional massless Dirac fermions fully confined within a smooth one-dimensional potential V(x)= - {\\alpha}/cosh({\\beta}x), which provides a good fit for potential profiles of existing top-gated graphene structures. We show that there is a threshold value of the characteristic potential strength {\\alpha}/{\\beta} for which the first mode appears, in striking contrast to the non-relativistic case. A simple relationship between the characteristic strength and the number of modes within the potential is found. An experimental setup is proposed for the observation of these modes. The proposed geometry could be utilized in future graphene-based devices with high on/off current ratios.

  15. Manifestations of topological effects in graphene

    E-Print Network [OSTI]

    Jiannis K. Pachos

    2008-12-05T23:59:59.000Z

    Graphene is a monoatomic layer of graphite with Carbon atoms arranged in a two dimensional honeycomb lattice configuration. It has been known for more than sixty years that the electronic structure of graphene can be modelled by two-dimensional massless relativistic fermions. This property gives rise to numerous applications, both in applied sciences and in theoretical physics. Electronic circuits made out of graphene could take advantage of its high electron mobility that is witnessed even at room temperature. In the theoretical domain the Dirac-like behavior of graphene can simulate high energy effects, such as the relativistic Klein paradox. Even more surprisingly, topological effects can be encoded in graphene such as the generation of vortices, charge fractionalization and the emergence of anyons. The impact of the topological effects on graphene's electronic properties can be elegantly described by the Atiyah-Singer index theorem. Here we present a pedagogical encounter of this theorem and review its various applications to graphene. A direct consequence of the index theorem is charge fractionalization that is usually known from the fractional quantum Hall effect. The charge fractionalization gives rise to the exciting possibility of realizing graphene based anyons that unlike bosons or fermions exhibit fractional statistics. Besides being of theoretical interest, anyons are a strong candidate for performing error free quantum information processing.

  16. Pseudospin entanglement and Bell test in graphene

    E-Print Network [OSTI]

    M. Kindermann

    2008-07-01T23:59:59.000Z

    We propose a way of producing and detecting pseudospin entanglement between electrons and holes in graphene. Electron-hole pairs are produced by a fluctuating potential and their entanglement is demonstrated by a current correlation measurement. The chirality of electrons in graphene facilitates a well-controlled Bell test with (pseudo-)spin projection angles defined in real space.

  17. The Hawking-Unruh phenomenon on graphene

    E-Print Network [OSTI]

    Alfredo Iorio; Gaetano Lambiase

    2012-09-03T23:59:59.000Z

    We find that, for a very specific shape of a monolayer graphene sample, a general relativistic-like description of a back-ground spacetime for graphene's conductivity electrons is very natural. The corresponding electronic local density of states is of finite temperature. This is a Hawking-Unruh effect that we propose to detect through an experiment with a Scanning Tunneling Microscope.

  18. Nanocomposite of graphene and metal oxide materials

    DOE Patents [OSTI]

    Liu, Jun; Aksay, Ilhan A.; Choi, Daiwon; Wang, Donghai; Yang, Zhenguo

    2012-09-04T23:59:59.000Z

    Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The nanocomposite materials exhibit a specific capacity of at least twice that of the metal oxide material without the graphene at a charge/discharge rate greater than about 10C.

  19. The Quantum Hall Effect in Graphene

    E-Print Network [OSTI]

    Paolo Cea

    2012-04-24T23:59:59.000Z

    We investigate the quantum Hall effect in graphene. We argue that in graphene in presence of an external magnetic field there is dynamical generation of mass by a rearrangement of the Dirac sea. We show that the mechanism breaks the lattice valley degeneracy only for the $n=0$ Landau levels and leads to the new observed $\

  20. Helicity -- from Clifford to Graphene

    E-Print Network [OSTI]

    Christian G. Boehmer; Louie Corpe

    2012-03-31T23:59:59.000Z

    We investigate two seemingly disjoint definitions of helicity, one commonly used in particle physics, the other one used when studying bilinear covariants of Clifford algebras. We can prove that the `mathematical' definition of helicity implies its `physical' counterpart. As an unexpected application of our result we show that the Hamiltonian describing the one-layer superconductor Graphene is proportional to the trace of an operator that is used in the `mathematical' definition of helicity.

  1. Graphene, neutrino mass and oscillation

    E-Print Network [OSTI]

    Z. Y. Wang

    2011-03-28T23:59:59.000Z

    A resolution of the Abraham-Minkowski dilemma is presented that other constant velocities can play the role of c in the theory of relativity. For example, in 2005 electrons of graphene were discovered to behave as if the coefficient is a Fermi velocity. Then we propose a conjecture for neutrinos to avoid the contradiction among two-component theory, negative rest mass-square and oscillation.

  2. Synergistic Effect of Fullerene-Capped Gold Nanoparticles on Graphene Electrochemical Supercapacitors

    E-Print Network [OSTI]

    Yong, Virginia; Hahn, H. Thomas

    2013-01-01T23:59:59.000Z

    Hybrid Filmsfor Supercapacitors,” Journal of PhysicalGraphene Electrochemical Supercapacitors Virginia Yong * ,Nanoparticles; Graphene; Supercapacitors; Energy Storage;

  3. Minnesota Nuclear Profile - Prairie Island

    U.S. Energy Information Administration (EIA) Indexed Site

    Prairie Island" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

  4. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2003 ­ August 31, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  5. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2003 ­ May 31, 2003 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distributions

  6. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island June 1, 2004 ­ August 31, 2004 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  7. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island December 1, 2003 ­ February 29, 2004 Prepared for Massachusetts.................................................................................................................... 11 Wind Speed Time Series........................................................................................................... 11 Wind Speed Distribution

  8. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island March 1, 2004 ­ May 31, 2004 Prepared for Massachusetts Technology...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  9. WIND DATA REPORT Thompson Island

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    WIND DATA REPORT Thompson Island September 1, 2003 ­ November 30, 2003 Prepared for Massachusetts...................................................................................................................... 9 Wind Speed Time Series............................................................................................................. 9 Wind Speed Distribution

  10. Intravalley Multiple Scattering of Quasiparticles in Graphene

    E-Print Network [OSTI]

    J. Y. Vaishnav; Justin Q. Anderson; Jamie D. Walls

    2011-05-28T23:59:59.000Z

    We develop a theoretical description of intravalley scattering of quasiparticles in graphene from multiple short-range scatterers of size much greater than the carbon-carbon bond length. Our theory provides a method to rapidly calculate the Green's function in graphene for arbitrary configurations of scatterers. We demonstrate that non-collinear multiple scattering trajectories generate pseudospin rotations that alter quasiparticle interference, resulting in significant modifications to the shape, intensity, and pattern of the interference fringes in the local density of states (LDOS). We illustrate these effects via theoretical calculations of the LDOS for a variety of scattering configurations in single layer graphene. A clear understanding of impurity scattering in graphene is a step towards exploiting graphene's unique properties to build future devices.

  11. Library Locations Locations other than Main Library

    E-Print Network [OSTI]

    Library Locations Locations other than Main Library Example: Feminist Studies HQ1410 .U54 2009 University of California, Santa Barbara Library www.library.ucsb.edu Updated 3-2014 A - B.......................................6 Central M - N..................................................Arts Library (Music Building) P

  12. STANDARD OPERATING PROCEDURE Location(s): ___________________________________________________

    E-Print Network [OSTI]

    Pawlowski, Wojtek

    of as hazardous waste. 8. Decontamination: Specific instructions: For light contamination of small areas or items12.1 STANDARD OPERATING PROCEDURE for PHENOL Location(s): ___________________________________________________ Chemical(s): Phenol Specific Hazards: May be fatal if inhaled. Harmful if absorbed through skin. Harmful

  13. Galveston Island and erosion

    E-Print Network [OSTI]

    Bolleter, Jim Mason

    1985-01-01T23:59:59.000Z

    . VITA 73 74 80 85 97 101 115 LIST OF TABLES Table Page 1. Ai rphoto Scale Determination with the Aid of a Base Map . . 16 2. Actual-vs-l4easured Photo Scale and Resulting Error 3. Tropical Cyclones Affecting the Texas Coast from 1952-1983... 17 64 4. Projected Sea-level Rise 72 5. Potential Sand Sources and Sinks for Galveston Island . . . . 80 Al. Vegetation-line Changes on West Beach from July 3, 1977 to September 22, 1983; Impact of Recent Storm Events AZ. Changes...

  14. Islands in the landscape

    E-Print Network [OSTI]

    T. Clifton; Andrei Linde; Navin Sivanandam

    2007-01-10T23:59:59.000Z

    The string theory landscape consists of many metastable de Sitter vacua, populated by eternal inflation. Tunneling between these vacua gives rise to a dynamical system, which asymptotically settles down to an equilibrium state. We investigate the effects of sinks to anti-de Sitter space, and show how their existence can change probabilities in the landscape. Sinks can disturb the thermal occupation numbers that would otherwise exist in the landscape and may cause regions that were previously in thermal contact to be divided into separate, thermally isolated islands.

  15. Nauru Island Effect Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNational Library of1, 2007 (nextNauru Island Effect Study S. A.

  16. Thematic Review Conservation of Biodiversity on Islands

    E-Print Network [OSTI]

    Thematic Review Conservation of Biodiversity on Islands: The contribution of the United Kingdom............................................................................................. 11 3. THE BIODIVERSITY OF ISLANDS INVOLVED WITH DI PROJECTS ........................................................................................... 49 6. THE DARWIN INITIATIVE'S CONTRIBUTION TO THE CBD'S ISLAND BIODIVERSITY PROGRAMME OF WORK

  17. Synthesis of graphene platelets by chemical and electrochemical route

    SciTech Connect (OSTI)

    Ramachandran, Rajendran; Felix, Sathiyanathan [Centre for Nanotechnology Research, VIT University, Vellore 632014, Tamil Nadu (India); Joshi, Girish M. [Materials Physics Division, School of Advanced Sciences, VIT University, Vellore 632014, Tamil Nadu (India); Raghupathy, Bala P.C., E-mail: balapraveen2000@yahoo.com [Centre for Nanotechnology Research, VIT University, Vellore 632014, Tamil Nadu (India); Research and Advanced Engineering Division (Materials), Renault Nissan Technology and Business Center India (P) Ltd., Chennai, Tamil Nadu (India); Jeong, Soon Kwan, E-mail: jeongsk@kier.re.kr [Climate Change Technology Research Division, Korea Institute of Energy Research, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Grace, Andrews Nirmala, E-mail: anirmalagrace@vit.ac.in [Centre for Nanotechnology Research, VIT University, Vellore 632014, Tamil Nadu (India); Climate Change Technology Research Division, Korea Institute of Energy Research, Yuseong-gu, Daejeon 305-343 (Korea, Republic of)

    2013-10-15T23:59:59.000Z

    Graphical abstract: A schematic showing the overall reduction process of graphite to reduced graphene platelets by chemical and electrochemical route. - Highlights: • Graphene was prepared by diverse routes viz. chemical and electrochemical methods. • NaBH{sub 4} was effective for removing oxygen functional groups from graphene oxide. • Sodium borohydride reduced graphene oxide (SRGO) showed high specific capacitance. • Electrochemical rendered a cheap route for production of graphene in powder form. - Abstract: Graphene platelets were synthesized from graphene oxide by chemical and electrochemical route. Under the chemical method, sodium borohydride and hydrazine chloride were used as reductants to produce graphene. In this paper, a novel and cost effective electrochemical method, which can simplify the process of reduction on a larger scale, is demonstrated. The electrochemical method proposed in this paper produces graphene in powder form with good yield. The atomic force microscopic images confirmed that the graphene samples prepared by all the routes have multilayers of graphene. The electrochemical process provided a new route to make relatively larger area graphene sheets, which will have interest for further patterning applications. Attempt was made to quantify the quantum of reduction using cyclic voltammetry and choronopotentiometry techniques on reduced graphene samples. As a measure in reading the specific capacitance values, a maximum specific capacitance value of 265.3 F/g was obtained in sodium borohydride reduced graphene oxide.

  18. Location and Geology Fig 1. The Macasty black shale

    E-Print Network [OSTI]

    , Quebec, is organic-rich black shale and hosting oil and gas. It is equivalent to the Ithaca shaleLocation and Geology Fig 1. The Macasty black shale in the Anticosti Island in the Gulf of St. d13C for calcite disseminated in the black shale range from 2.6o to 2.8 / The values are lower

  19. Small-Scale Solar Grants (Rhode Island)

    Broader source: Energy.gov [DOE]

    The Rhode Island Economic Development Corporation (RIEDC) provides incentives for renewable-energy projects. Incentive programs are funded by the Rhode Island Renewable Energy Fund (RIREF) and...

  20. Energy Transition Initiative: Islands Playbook (Book) | OSTI...

    Office of Scientific and Technical Information (OSTI)

    Energy Transition Initiative: Islands Playbook (Book) Re-direct Destination: The Island Energy Playbook (the Playbook) provides an action-oriented guide to successfully initiating,...

  1. Strongly Coupled Graphene on the Lattice

    E-Print Network [OSTI]

    Timo A. Lähde; Joaquín E. Drut

    2011-11-03T23:59:59.000Z

    The two-dimensional carbon allotrope graphene has recently attracted a lot of attention from researchers in the disciplines of Lattice Field Theory, Lattice QCD and Monte Carlo calculations. This interest has been prompted by several remarkable properties of the conduction electrons in graphene. For instance, the conical band structure of graphene at low energies is strongly reminiscent of relativistic Dirac fermions. Also, due the low Fermi velocity of v_F = c/300, where c is the speed of light in vacuum, the physics of the conduction electrons in graphene is qualitatively similar to Quantum Electrodynamics in a strongly coupled regime. In turn, this opens up the prospect of the experimental realization of gapped, strongly correlated states in the electronic phase diagram of graphene. Here, we review the experimental and theoretical motivations for Lattice Field Theory studies of graphene, and describe the directions that such research is likely to progress in during the next few years. We also give a brief overview of the two main lattice theories of graphene, the hexagonal Hubbard theory and the low-energy Dirac theory. Finally, we describe the prospect of extracting response functions, such as the electric conductivity, using Lattice Field Theory calculations.

  2. Magnetization dynamics of cobalt grown on graphene

    SciTech Connect (OSTI)

    Berger, A. J.; White, S. P.; Adur, R.; Pu, Y.; Hammel, P. C., E-mail: hammel@physics.osu.edu [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Amamou, W. [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States); Kawakami, R. K. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States); Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States)

    2014-05-07T23:59:59.000Z

    Ferromagnetic resonance (FMR) spin pumping is a rapidly growing field which has demonstrated promising results in a variety of material systems. This technique utilizes the resonant precession of magnetization in a ferromagnet to inject spin into an adjacent non-magnetic material. Spin pumping into graphene is attractive on account of its exceptional spin transport properties. This article reports on FMR characterization of cobalt grown on chemical vapor deposition graphene and examines the validity of linewidth broadening as an indicator of spin pumping. In comparison to cobalt samples without graphene, direct contact cobalt-on-graphene exhibits increased FMR linewidth—an often used signature of spin pumping. Similar results are obtained in Co/MgO/graphene structures, where a 1?nm MgO layer acts as a tunnel barrier. However, magnetometry, magnetic force microscopy, and Kerr microscopy measurements demonstrate increased magnetic disorder in cobalt grown on graphene, perhaps due to changes in the growth process and an increase in defects. This magnetic disorder may account for the observed linewidth enhancement due to effects such as two-magnon scattering or mosaicity. As such, it is not possible to conclude successful spin injection into graphene from FMR linewidth measurements alone.

  3. High performance vertical tunneling diodes using graphene/hexagonal boron nitride/graphene hetero-structure

    SciTech Connect (OSTI)

    Hwan Lee, Seung; Lee, Jia; Ho Ra, Chang; Liu, Xiaochi; Hwang, Euyheon [Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Sup Choi, Min [Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Hee Choi, Jun [Frontier Research Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Yongin, Gyeonggi-do 446-711 (Korea, Republic of); Zhong, Jianqiang; Chen, Wei [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Jong Yoo, Won, E-mail: yoowj@skku.edu [Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

    2014-02-03T23:59:59.000Z

    A tunneling rectifier prepared from vertically stacked two-dimensional (2D) materials composed of chemically doped graphene electrodes and hexagonal boron nitride (h-BN) tunneling barrier was demonstrated. The asymmetric chemical doping to graphene with linear dispersion property induces rectifying behavior effectively, by facilitating Fowler-Nordheim tunneling at high forward biases. It results in excellent diode performances of a hetero-structured graphene/h-BN/graphene tunneling diode, with an asymmetric factor exceeding 1000, a nonlinearity of ?40, and a peak sensitivity of ?12?V{sup ?1}, which are superior to contending metal-insulator-metal diodes, showing great potential for future flexible and transparent electronic devices.

  4. Synthesis of reduced graphene oxide/ZnO nanorods composites on graphene coated PET flexible substrates

    SciTech Connect (OSTI)

    Huang, Lei, E-mail: leihuang@shnu.edu.cn; Guo, Guilue; Liu, Yang; Chang, Quanhong; Shi, Wangzhou

    2013-10-15T23:59:59.000Z

    Graphical abstract: - Highlights: • ZnO nanorods synthesized on CVD-graphene and rGO surfaces, respectively. • ZnO/CVD-graphene and ZnO/rGO form a distinctive porous 3D structure. • rGO/ZnO nanostructures possibility in energy storage devices. - Abstract: In this work, reduced graphene oxide (rGO)/ZnO nanorods composites were synthesized on graphene coated PET flexible substrates. Both chemical vapor deposition (CVD) graphene and reduced graphene oxide (rGO) films were prepared following by hydrothermal growth of vertical aligned ZnO nanorods. Reduced graphene sheets were then spun coated on the ZnO materials to form a three dimensional (3D) porous nanostructure. The morphologies of the ZnO/CVD graphene and ZnO/rGO were investigated by SEM, which shows that the ZnO nanorods grown on rGO are larger in diameters and have lower density compared with those grown on CVD graphene substrate. As a result of fact, the rough surface of nano-scale ZnO on rGO film allows rGO droplets to seep into the large voids of ZnO nanorods, then to form the rGO/ZnO hierarchical structure. By comparison of the different results, we conclude that rGO/ZnO 3D nanostructure is more desirable for the application of energy storage devices.

  5. Impact of graphene polycrystallinity on the performance of graphene field-effect transistors

    SciTech Connect (OSTI)

    Jiménez, David; Chaves, Ferney [Departament d'Enginyeria Electrònica, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193-Bellaterra (Spain); Cummings, Aron W.; Van Tuan, Dinh [ICN2, Institut Català de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona) (Spain); Kotakoski, Jani [Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien (Austria); Department of Physics, University of Helsinki, P.O. Box 43, 00014 University of Helsinki (Finland); Roche, Stephan [ICN2, Institut Català de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona) (Spain); ICREA, Institució Catalana de Recerca i Estudis Avançats, 08070 Barcelona (Spain)

    2014-01-27T23:59:59.000Z

    We have used a multi-scale physics-based model to predict how the grain size and different grain boundary morphologies of polycrystalline graphene will impact the performance metrics of graphene field-effect transistors. We show that polycrystallinity has a negative impact on the transconductance, which translates to a severe degradation of the maximum and cutoff frequencies. On the other hand, polycrystallinity has a positive impact on current saturation, and a negligible effect on the intrinsic gain. These results reveal the complex role played by graphene grain boundaries and can be used to guide the further development and optimization of graphene-based electronic devices.

  6. Electronic states in epitaxial graphene fabricated on silicon carbide

    SciTech Connect (OSTI)

    Davydov, S. Yu., E-mail: Sergei_Davydov@mail.ru [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation)

    2011-08-15T23:59:59.000Z

    An analytical expression for the density of states of a graphene monolayer interacting with a silicon carbide surface (epitaxial graphene) is derived. The density of states of silicon carbide is described within the Haldane-Anderson model. It is shown that the graphene-substrate interaction results in a narrow gap of {approx}0.01-0.06 eV in the density of states of graphene. The graphene atom charge is estimated; it is shown that the charge transfer from the substrate is {approx}10{sup -3}-10{sup -2}e per graphene atom.

  7. Kinetics of monolayer graphene growth by segregation on Pd(111)

    SciTech Connect (OSTI)

    Mok, H. S.; Murata, Y.; Kodambaka, S., E-mail: kodambaka@ucla.edu [Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095 (United States); Ebnonnasir, A.; Ciobanu, C. V. [Department of Mechanical Engineering and Materials Science Program, Colorado School of Mines, Golden, Colorado 80401 (United States); Nie, S.; McCarty, K. F. [Sandia National Laboratories, Livermore, California 94550 (United States)

    2014-03-10T23:59:59.000Z

    Using in situ low-energy electron microscopy and density functional theory calculations, we follow the growth of monolayer graphene on Pd(111) via surface segregation of bulk-dissolved carbon. Upon lowering the substrate temperature, nucleation of graphene begins on graphene-free Pd surface and continues to occur during graphene growth. Measurements of graphene growth rates and Pd surface work functions establish that this continued nucleation is due to increasing C adatom concentration on the Pd surface with time. We attribute this anomalous phenomenon to a large barrier for attachment of C adatoms to graphene coupled with a strong binding of the non-graphitic C to the Pd surface.

  8. Unusual thermopower of inhomogeneous graphene grown by chemical vapor deposition

    SciTech Connect (OSTI)

    Nam, Youngwoo, E-mail: youngwoo.nam@chalmers.se [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Sun, Jie; Lindvall, Niclas; Yurgens, August [Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Jae Yang, Seung; Rae Park, Chong [Department of Materials Science and Engineering, Seoul National University, Seoul 151-747 (Korea, Republic of); Woo Park, Yung [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-01-13T23:59:59.000Z

    We report on thermopower (TEP) and resistance measurements of inhomogeneous graphene grown by chemical vapor deposition (CVD). Unlike the conventional resistance of pristine graphene, the gate-dependent TEP shows a large electron-hole asymmetry. This can be accounted for by inhomogeneity of the CVD-graphene where individual graphene regions contribute with different TEPs. At the high magnetic field and low temperature, the TEP has large fluctuations near the Dirac point associated with the disorder in the CVD-graphene. TEP measurements reveal additional characteristics of CVD-graphene, which are difficult to obtain from the measurement of resistance alone.

  9. Möbius Graphene Strip as Topological Insulator

    E-Print Network [OSTI]

    Z. L. Guo; Z. R. Gong; H. Dong; C. P. Sun

    2009-06-09T23:59:59.000Z

    We study the electronic properties of M\\"{o}bius graphene strip with a zigzag edge. We show that such graphene strip behaves as a topological insulator with a gapped bulk and a robust metallic surface, which enjoys some features due to its nontrivial topology of the spatial configuration, such as the existence of edge states and the non-Abelian induced gauge field. We predict that the topological properties of the M\\"{o}bius graphene strip can be experimentally displayed by the destructive interference in the transmission spectrum, and the robustness of edge states under certain perturbations.

  10. Thermal fluctuations of free standing graphene

    E-Print Network [OSTI]

    F. L. Braghin; N. Hasselmann

    2010-06-22T23:59:59.000Z

    We use non-perturbative renormalization group techniques to calculate the momentum dependence of thermal fluctuations of graphene, based on a self-consistent calculation of the momentum dependent elastic constants of a tethered membrane. We find a sharp crossover from the perturbative to the anomalous regime, in excellent agreement with Monte Carlo results for graphene, and give an accurate value for the crossover scale. Our work strongly supports the notion that graphene is well described as a tethered membrane. Ripples emerge naturally from our analysis.

  11. Dissipative plasmon solitons in graphene nanodisk arrays

    E-Print Network [OSTI]

    Smirnova, Daria A; Smirnov, Lev A; Kivshar, Yuri S

    2014-01-01T23:59:59.000Z

    We study nonlinear modes in one-dimensional arrays of doped graphene nanodisks with Kerr-type nonlinear response in the presence of an external electric field. We present the theoretical model describing the evolution of the disks' polarizations, taking into account intrinsic graphene losses and dipole-dipole coupling between the graphene nanodisks. We reveal that this nonlinear system can support discrete dissipative scalar solitons of both longitudinal and transverse polarizations, as well as vector solitons composed of two mutually coupled polarization components. We demonstrate the formation of stable resting and moving localized modes under controlling guidance of the external driving field.

  12. Extremely compliant and highly stretchable patterned graphene

    SciTech Connect (OSTI)

    Zhu, Shuze; Huang, Yinjun; Li, Teng, E-mail: LiT@umd.edu [Department of Mechanical Engineering and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742 (United States)

    2014-04-28T23:59:59.000Z

    Graphene is intrinsically ultra-stiff in its plane. Its huge mechanical mismatch when interfacing with ultra-compliant biological tissues and elastomers (7–9 orders of magnitude difference in stiffness) poses significant challenge in its application to functional devices such as epidermal electronics and sensing prosthesis. We offer a feasible and promising solution to this significant challenge by suitably patterning graphene into a nanomesh. Through systematic coarse-grained simulations, we show that graphene nanomesh can be made extremely compliant with nearly zero stiffness up to about 20% elongation and then remain highly compliant up to about 50% elongation.

  13. Multi-plasmon absorption in graphene

    E-Print Network [OSTI]

    Marinko Jablan; Darrick E. Chang

    2015-01-21T23:59:59.000Z

    We show that graphene possesses a strong nonlinear optical response in the form of multi-plasmon absorption, with exciting implications in classical and quantum nonlinear optics. Specifically, we predict that graphene nano-ribbons can be used as saturable absorbers with low saturation intensity in the far-infrared and terahertz spectrum. Moreover, we predict that two-plasmon absorption and extreme localization of plasmon fields in graphene nano-disks can lead to a plasmon blockade effect, in which a single quantized plasmon strongly suppresses the possibility of exciting a second plasmon.

  14. Direct growth of graphene on Si(111)

    SciTech Connect (OSTI)

    Thanh Trung, Pham, E-mail: phamtha@fundp.ac.be; Joucken, Frédéric; Colomer, Jean-François; Robert, Sporken [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), 61 Rue de Bruxelles, 5000 Namur (Belgium); Campos-Delgado, Jessica; Raskin, Jean-Pierre [Electrical Engineering (ELEN), Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Université catholique de Louvain UCL, 3 place du Levant, Louvain-la-Neuve (Belgium); Hackens, Benoît; Santos, Cristiane N. [Nanoscopic physics (NAPS), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain UCL, 2 chemin du Cyclotron, Louvain-la-Neuve (Belgium)

    2014-06-14T23:59:59.000Z

    Due to the need of integrated circuit in the current silicon technology, the formation of graphene on Si wafer is highly desirable, but is still a challenge for the scientific community. In this context, we report the direct growth of graphene on Si(111) wafer under appropriate conditions using an electron beam evaporator. The structural quality of the material is investigated in detail by reflection high energy electron diffraction, Auger electron spectroscopy, X-ray photoemission spectroscopy, Raman spectroscopy, high resolution scanning electron microscopy, atomic force microscopy, and scanning tunneling microscopy. Our experimental results confirm that the quality of graphene is strongly dependent on the growth time during carbon atoms deposition.

  15. Remedial Action Work Plan Amchitka Island Mud Pit Closures

    SciTech Connect (OSTI)

    DOE/NV

    2001-04-05T23:59:59.000Z

    This remedial action work plan presents the project organization and construction procedures developed for the performance of the remedial actions at U.S. Department of Energy (DOE's) sites on Amchitka Island, Alaska. During the late1960s and early 1970s, the U.S. Department of Defense and the U.S. Atomic Energy Commission (the predecessor agency to DOE) used Amchitka Island as a site for underground nuclear tests. A total of nine sites on the Island were considered for nuclear testing; however, tests were only conducted at three sites (i.e., Long Shot in 1965, Milrow in 1969, and Cannikin in 1971). In addition to these three sites, large diameter emplacement holes were drilled in two other locations (Sites D and F) and an exploratory hole was in a third location (Site E). It was estimated that approximately 195 acres were disturbed by drilling or preparation for drilling in conjunction with these activities. The disturbed areas include access roads, spoil-disposal areas, mud pits which have impacted the environment, and an underground storage tank at the hot mix plant which was used to support asphalt-paving operations on the island. The remedial action objective for Amchitka Island is to eliminate human and ecological exposure to contaminants by capping drilling mud pits, removing the tank contents, and closing the tank in place. The remedial actions will meet State of Alaska regulations, U.S. Fish and Wildlife Service refuge management goals, address stakeholder concerns, and address the cultural beliefs and practices of the native people. The U.S. Department of Energy, Nevada Operations Office will conduct work on Amchitka Island under the authority of the Comprehensive Emergency Response, Compensation, and Liability Act. Field activities are scheduled to take place May through September 2001. The results of these activities will be presented in a subsequent Closure Report.

  16. Graphene with geometrically induced vorticity

    E-Print Network [OSTI]

    Jiannis K. Pachos; Michael Stone; Kristan Temme

    2008-03-26T23:59:59.000Z

    At half filling, the electronic structure of graphene can be modelled by a pair of free two-dimensional Dirac fermions. We explicitly demonstrate that in the presence of a geometrically induced gauge field, an everywhere-real Kekule modulation of the hopping matrix elements can correspond to a non-real Higgs field with non-trivial vorticity. This provides a natural setting for fractionally charged vortices with localized zero modes. For fullerene-like molecules we employ the index theorem to demonstrate the existence of six low-lying states that do not depend strongly on the Kekule-induced mass gap.

  17. Surface plasmons for doped graphene

    E-Print Network [OSTI]

    Bordag, M

    2015-01-01T23:59:59.000Z

    Within the Dirac model for the electronic excitations of graphene, we calculate the full polarization tensor with finite mass and chemical potential. It has, besides the (00)-component, a second form factor, which must be accounted for. We obtain explicit formulas for both form factors and for the reflection coefficients. Using these, we discuss the regions in the momentum-frequency plane where plasmons may exist and give numeric solutions for the plasmon dispersion relations. It turns out that plasmons exist for both, TE and TM polarizations over the whole range of the ratio of mass to chemical potential, except for zero chemical potential, where only a TE plasmon exists.

  18. Bilayer Graphene Gets a Bandgap

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer Graphene Gets a

  19. Bilayer Graphene Gets a Bandgap

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer Graphene Gets

  20. Bilayer Graphene Gets a Bandgap

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer Graphene

  1. Bilayer Graphene Gets a Bandgap

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareers Apply for aCould Work as HeatBilayer GrapheneBilayer

  2. EIS-0006: Wind Turbine Generator System, Block Island, Rhode Island

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy prepared this EIS to evaluate the environmental impacts of installing and operating a large experimental wind turbine, designated the MOD-OA, which is proposed to be installed on a knoll in Rhode Island's New Meadow Hill Swamp, integrated with the adjacent Block Island Power Company power plant and operated to supply electricity to the existing utility network.

  3. Finite temperature Casimir effect for graphene

    E-Print Network [OSTI]

    Ignat V. Fialkovsky; Valery N. Marachevsky; Dmitri V. Vassilevich

    2011-02-09T23:59:59.000Z

    We adopt the Dirac model for quasiparticles in graphene and calculate the finite temperature Casimir interaction between a suspended graphene layer and a parallel conducting surface. We find that at high temperature the Casimir interaction in such system is just one half of that for two ideal conductors separated by the same distance. In this limit single graphene layer behaves exactly as a Drude metal. In particular, the contribution of the TE mode is suppressed, while one of the TM mode saturates the ideal metal value. Behaviour of the Casimir interaction for intermediate temperatures and separations accessible for an experiment is studied in some detail. We also find an interesting interplay between two fundamental constants of graphene physics: the fine structure constant and the Fermi velocity.

  4. Terahertz graphene lasers: Injection versus optical pumping

    SciTech Connect (OSTI)

    Ryzhii, Victor; Otsuji, Taiichi [Research Institute for Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Ryzhii, Maxim [Computational Nanoelectronics Laboratory, University of Aizu, Aizu-Wakamatsu 965-8580 (Japan); Mitin, Vladimir [Department of Electrical Engineering, University at Buffalo, SUNY, Buffalo, New York 14260-1920 (United States)

    2013-12-04T23:59:59.000Z

    We analyze the formation of nonequilibrium states in optically pumped graphene layers and in forward-biased graphene structures with lateral p-i-n junctions and consider the conditions of population inversion and lasing. The model used accounts for intraband and interband relaxation processes as well as deviation of the optical phonon system from equilibrium. As shown, optical pumping suffers from a significant heating of both the electron-hole plasma and the optical phonon system, which can suppress the formation of population inversion. In the graphene structures with p-i-n junction, the injected electrons and holes have relatively low energies, so that the effect of cooling can be rather pronounced, providing a significant advantage of the injection pumping in realization of graphene terahertz lasers.

  5. Electrical and Mechanical Properties of Graphene.

    E-Print Network [OSTI]

    Bao, Wenzhong

    2011-01-01T23:59:59.000Z

    ??Graphene is an exciting new atomically-thin two-dimensional (2D) system of carbon atoms organized in a hexagonal lattice structure. This "wonder material" has been extensively studied… (more)

  6. Schwinger pair creation in multilayer graphene

    E-Print Network [OSTI]

    M. A. Zubkov

    2012-03-31T23:59:59.000Z

    The low energy effective field model for the multilayer graphene (at ABC stacking) in external Electric field is considered. The Schwinger pair creation rate and the vacuum persistence probability are calculated using the semi - classical approach.

  7. Near-zero modes in superconducting graphene

    E-Print Network [OSTI]

    Ghaemi, Pouyan

    Vortices in the simplest superconducting state of graphene contain very-low-energy excitations whose existence is connected to an index theorem that applies strictly to an approximate form of the relevant Bogoliubov–de ...

  8. Electrical and Mechanical Properties of Graphene

    E-Print Network [OSTI]

    Bao, Wenzhong

    2011-01-01T23:59:59.000Z

    in carbon nanotube Josephson Junctions, Phys. Rev. Lett. ,45 Fig. 3-1 (a) Schematic diagram of Josephson junction. (b)An SEM image of a xviii graphene Josephson junction

  9. Electrical Transport in Carbon Nanotubes and Graphene

    E-Print Network [OSTI]

    Liu, Gang

    2010-01-01T23:59:59.000Z

    nanotubes and graphene are the most popular Carbon material in the condensed matter research. Based on energy2D energy dispersion as Fig. II-2. For a nanotubes in

  10. Relativistic dynamics and Dirac particles in graphene

    E-Print Network [OSTI]

    Gu, Nan, Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Graphene, a two-dimensional hexagonal lattice of carbon, has jumped to the forefront of condensed matter research in the past few years as a high quality two-dimensional electron system with intriguing scientific and ...

  11. Self-weakening in lithiated graphene electrodes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    online 1 February 2013 a b s t r a c t We present a molecular dynamics study of the fracture mechanisms of lithiated graphene. Our modeling results reveal that lithium diffusion...

  12. Outstanding performance of activated graphene based supercapacitors...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Outstanding performance of activated graphene based supercapacitors in ionic liquid electrolyte from 50 to 80 1C Wan-Yu Tsai a , Rongying Lin a , Shanthi Murali c , Li Li Zhang c...

  13. Magnetic properties in graphene-graphane superlattices

    E-Print Network [OSTI]

    Lee, Joo-Hyoung

    The magnetic properties of graphene-graphane superlattices with zigzag interfaces and separately varying widths are investigated by first-principles density functional calculations. It is demonstrated that magnetic states ...

  14. Direct transfer of graphene onto flexible substrates

    E-Print Network [OSTI]

    Araujo, P. T.

    In this paper we explore the direct transfer via lamination of chemical vapor deposition graphene onto different flexible substrates. The transfer method investigated here is fast, simple, and does not require an intermediate ...

  15. Detecting topological currents in graphene superlattices

    E-Print Network [OSTI]

    Gorbachev, R. V.

    Topological materials may exhibit Hall-like currents flowing transversely to the applied electric field even in the absence of a magnetic field. In graphene superlattices, which have broken inversion symmetry, topological ...

  16. Graphene optical-to-thermal converter

    E-Print Network [OSTI]

    Manjavacas, Alejandro; Greffet, Jean-Jacques; de Abajo, F Javier García

    2014-01-01T23:59:59.000Z

    Infrared plasmons in doped graphene nanostructures produce large optical absorption that can be used for narrow-band thermal light emission at tunable frequencies that strongly depend on the doping charge. By virtue of Kirchhoff's law, thermal light emission is proportional to the absorption, thus resulting in narrow emission lines associated with the electrically controlled plasmons of heated graphene. Here we show that realistic designs of graphene plasmonic structures can release over 90% of the emission through individual infrared lines with 1% bandwidth. We examine anisotropic graphene structures in which efficient heating can be produced upon optical pumping tuned to a plasmonic absorption resonance situated in the blue region relative to the thermal emission. An incoherent thermal light converter is thus achieved. Our results open a radically different approach for designing tunable nanoscale infrared light sources.

  17. Graphene-Based Ambipolar RF Mixers

    E-Print Network [OSTI]

    Wang, Han

    The combination of the unique properties of graphene with new device concepts and nanotechnology can overcome some of the main limitations of traditional electronics in terms of maximum frequency, linearity, and power ...

  18. Charge, spin and pseudospin in graphene

    E-Print Network [OSTI]

    Abanin, Dmitry A

    2008-01-01T23:59:59.000Z

    Graphene, a one-atom-thick form of carbon, has emerged in the last few years as a fertile electron system, highly promising for both fundamental research and applications. In this thesis we consider several topics in ...

  19. On zero energy states in graphene

    E-Print Network [OSTI]

    C. -L. Ho; P. Roy

    2014-10-02T23:59:59.000Z

    We obtain zero energy states in graphene for a number of potentials and discuss the relation of the decoupled Schr\\"odinger-like equations for the the spinor components with non relativistic $\\cal{PT}$ symmetric quantum mechanics.

  20. Long Island Solar Farm Project Overview

    E-Print Network [OSTI]

    Ohta, Shigemi

    Long Island Solar Farm #12;Project Overview The Long Island Solar Farm (LISF) is a 32-megawatt. Project Developer/Owner/Operator: Long Island Solar Farm, LLC (BP Solar & MetLife) Purchaser of Power and construct arrays ~ 2 years of output (88,000 MWh equivalent) Long Island Solar Farm #12;Other Pollutants

  1. Island Political Economy Geoff Bertram & Bernard Poirine

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    323 Chapter 10 Island Political Economy Geoff Bertram & Bernard Poirine Introduction In this chapter we build on the observation that island economies, and especially small ones (population below one of development strategies. Common elements of "islandness" may serve to define island economies as a general

  2. Lattice quantum electrodynamics for graphene

    E-Print Network [OSTI]

    Alessandro Giuliani; Vieri Mastropietro; Marcello Porta

    2011-07-24T23:59:59.000Z

    The effects of gauge interactions in graphene have been analyzed up to now in terms of effective models of Dirac fermions. However, in several cases lattice effects play an important role and need to be taken consistently into account. In this paper we introduce and analyze a lattice gauge theory model for graphene, which describes tight binding electrons hopping on the honeycomb lattice and interacting with a three-dimensional quantum U(1) gauge field. We perform an exact Renormalization Group analysis, which leads to a renormalized expansion that is finite at all orders. The flow of the effective parameters is controlled thanks to Ward Identities and a careful analysis of the discrete lattice symmetry properties of the model. We show that the Fermi velocity increases up to the speed of light and Lorentz invariance spontaneously emerges in the infrared. The interaction produces critical exponents in the response functions; this removes the degeneracy present in the non interacting case and allow us to identify the dominant excitations. Finally we add mass terms to the Hamiltonian and derive by a variational argument the correspondent gap equations, which have an anomalous non-BCS form, due to the non trivial effects of the interaction.

  3. Graphene, Lattice QFT and Symmetries

    E-Print Network [OSTI]

    L. B Drissi; E. H Saidi; M. Bousmina

    2011-03-07T23:59:59.000Z

    Borrowing ideas from tight binding model, we propose a board class of Lattice QFT models that are classified by the ADE Lie algebras. In the case of su(N) series, we show that the couplings between the quantum states living at the first nearest neighbor sites of the lattice $\\mathcal{L}_{su(N)}$ are governed by the complex fundamental representations \\underline{${{\\mathbf{N}}}$} and $\\bar{{\\mathbf{N}}}$ of $su(N)$; and the second nearest neighbor interactions are described by its adjoint $\\underline{\\mathbf{N}} \\otimes \\bar{\\mathbf{N}}$. The lattice models associated with the leading su(2), su(3) and su(4) cases are explicitly studied and their fermionic field realizations are given. It is also shown that the su(2) and su(3) models describe respectively the electronic properties of the acetylene chain and the graphene. It is established as well that the energy dispersion of the first nearest neighbor couplings is completely determined by the $A_{N}$ roots $ \\mathbf{\\alpha}$ through the typical dependence $N/2+\\sum_{roots}\\cos(\\mathbf{k}.\\alpha) $ with $\\mathbf{k}$ the wave vector. Other features such as DE extension and other applications are also discussed. Keywords: Tight Binding Model, Graphene, Lattice QFT, ADE Symmetries.

  4. Laser-induced quantum pumping in graphene

    SciTech Connect (OSTI)

    San-Jose, Pablo [Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, 28006 Madrid (Spain); Prada, Elsa; Kohler, Sigmund [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid (Spain); Schomerus, Henning [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

    2012-10-08T23:59:59.000Z

    We investigate non-adiabatic electron pumping in graphene generated by laser irradiation with linear polarization parallel or perpendicular to the transport direction. Transport is dominated by the spatially asymmetric excitation of electrons from evanescent into propagating modes. For a laser with parallel polarization, the pumping response exhibits a subharmonic resonant enhancement which directly probes the Fermi energy; no such enhancement occurs for perpendicular polarization. The resonance mechanism relies on the chirality of charge carriers in graphene.

  5. Anomalous confined electron states in graphene superlattices

    SciTech Connect (OSTI)

    Anh Le, H. [Advanced Institute for Science and Technology (AIST), Hanoi University of Science and Technology (HUST), Hanoi 10000 (Viet Nam); Chien Nguyen, D. [School of Engineering Physics, HUST, Hanoi 10000 (Viet Nam); Nam Do, V., E-mail: vannam.do@gmail.com [Advanced Institute for Science and Technology (AIST), Hanoi University of Science and Technology (HUST), Hanoi 10000 (Viet Nam); Institute for Computational Science and Engineering (ICSE), HUST, Hanoi 10000 (Viet Nam)

    2014-07-07T23:59:59.000Z

    We show that periodic scalar potentials can induce the localization of some electronic states in graphene. Particularly, localized states are found at energies outside the potential variation range and embedded in the continuum spectrum of delocalized ones. The picture of the connection of wave functions with typical symmetries defined in relevant-edge nanoribbons is employed to explain the formation of the electronic structure and to characterize/classify eigen-states in graphene superlattices.

  6. Advances in the CVD growth of graphene for electronics applications

    E-Print Network [OSTI]

    Hofmann, Mario

    2012-01-01T23:59:59.000Z

    Graphene, a monoatomic sheet of graphite, has recently received significant attention because of its potential impact in a wide variety of research areas. This thesis presents progress on improving the quality of graphene ...

  7. Graphene oxide-based materials : synthesis, characterization and applications.

    E-Print Network [OSTI]

    Zhou, Xiaozhu.

    2010-01-01T23:59:59.000Z

    ??In this study, the properties and applications of graphene oxide-based materials have been explored. Specifically, graphene oxide, i.e. a single layer of graphite oxide, reduced… (more)

  8. Direct observation of a dispersionless impurity band in hydrogenated graphene

    E-Print Network [OSTI]

    Haberer, D.

    We show with angle-resolved photoemission spectroscopy that a new energy band appears in the electronic structure of electron-doped hydrogenated monolayer graphene (H-graphene). Its occupation can be controlled with the ...

  9. Doped graphene nanohole arrays for flexible transparent conductors

    E-Print Network [OSTI]

    Liu, Jianwei; Xu, Guowei; Rochford, Caitlin; Lu, Rongtao; Wu, Judy; Edwards, Christina M.; Berrie, Cindy L.; Chen, Zhijun; Maroni, Victor A.

    2011-07-15T23:59:59.000Z

    Graphene nanohole arrays (GNAs) were fabricated using nanoimprint lithography. The improved optical transmittance of GNAs is primarily due to the reduced surface coverage of graphene from the nanohole fabrication. Importantly, the exposed edges...

  10. Packing efficiency and accessible surface area of crumpled graphene

    E-Print Network [OSTI]

    Cranford, Steven Wayne

    Graphene holds promise as an ultracapacitor due to its high specific surface area and intrinsic capacitance. To exploit both, a maximum surface area must be accessible while the two-dimensional (2D) graphene is deformed ...

  11. Anisotropic Etching and Nanoribbon Formation in Single-Layer Graphene

    E-Print Network [OSTI]

    Campos, Leonardo

    We demonstrate anisotropic etching of single-layer graphene by thermally activated nickel nanoparticles. Using this technique, we obtain sub-10-nm nanoribbons and other graphene nanostructures with edges aligned along a ...

  12. Low-dimensional carbon nanotube and graphene devices

    E-Print Network [OSTI]

    Scard, Philip

    2010-10-12T23:59:59.000Z

    -jet printing of nanotubes directly onto GaAs. Although only one atom thick, graphene is macroscopic in area and must be patterned to confine conduction; room temperature transistor behaviour requires graphene ribbons only a few nanometres wide. This work...

  13. RF performance of short channel graphene field-effect transistor

    E-Print Network [OSTI]

    Wu, Y. Q.

    In this paper, the authors present experimental studies on transport characteristics of graphene FETs with channel lengths down to 70 nm. The factors limiting the performance of short channel graphene devices are discussed. ...

  14. Functional Graphenic Materials Via a Johnson?Claisen Rearrangement

    E-Print Network [OSTI]

    Swager, Timothy M.

    Current research in materials has devoted much attention to graphene, with a considerable amount of the chemical manipulation going through the oxidized state of the material, known as graphene oxide (GO). In this report, ...

  15. Choosing a gate dielectric for graphene based transistors

    E-Print Network [OSTI]

    Hsu, Pei-Lan, M. Eng. Massachusetts Institute of Technology

    2008-01-01T23:59:59.000Z

    Much attention has recently been focused on graphene as an alternative semiconductor to silicon. Transistors with graphene conduction channels have only recently been fabricated and their performance remains to be optimized. ...

  16. Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Graphene-a single layer of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned...

  17. Electronic and magnetic properties of C-adsorbed graphene: a...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    C-adsorbed graphene: a first-principles study . Electronic and magnetic properties of C-adsorbed graphene: a first-principles study . Abstract: Using density functional theory, we...

  18. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Wednesday, 26 March 2008 00:00 Prospective challengers to...

  19. Au-free Ohmic Contacts to Gallium Nitride and Graphene

    E-Print Network [OSTI]

    Ravikirthi, Pradhyumna

    2014-08-10T23:59:59.000Z

    This work deals with Au-free contact metallization schemes for gallium nitride (GaN) and graphene semiconductors. Graphene and gallium nitride are promising materials that can potentially be integrated together in the near future for high frequency...

  20. BN/Graphene/BN Transistors for RF Applications

    E-Print Network [OSTI]

    Taychatanapat, Thiti

    In this letter, we demonstrate the first BN/graphene/BN field-effect transistor for RF applications. This device structure can preserve the high mobility and the high carrier velocity of graphene, even when it is sandwiched ...

  1. Molecular dynamics simulation of nanoporous graphene for selective gas separation

    E-Print Network [OSTI]

    Au, Harold (Harold S.)

    2012-01-01T23:59:59.000Z

    Graphene with sub-nanometer sized pores has the potential to act as a filter for gas separation with considerable efficiency gains compared to traditional technologies. Nanoporous graphene membranes are expected to yield ...

  2. Outline Phonon spectra of graphene Raman spectra of graphene Crystal lattice dynamics

    E-Print Network [OSTI]

    Seminar Heng Wang University of Konstanz July 11, 2013 Heng Wang University of Konstanz () Crystal lattice Raman spectra of graphene What is Raman scattering Applications of Raman spectroscopy of graphene Heng (2013). Heng Wang University of Konstanz () Crystal lattice dynamics July 11, 2013 3 / 19 #12;Outline

  3. Climate Action Plan (Rhode Island)

    Broader source: Energy.gov [DOE]

    In the fall of 2001, the Department of Environmental Management (DEM), the RI State Energy Office (SEO), and the Governor's office convened the Rhode Island Greenhouse Gas Stakeholder Project in...

  4. Pacific Islands Region News Release

    E-Print Network [OSTI]

    Pacific Islands Region News Release Contact: Wende Goo FOR IMMEDIATE RELEASE 808-721-4098 May 27 of these unique twins by contributing more than 100 hours of work to construct a holding pen for the young seal

  5. Island Cosmology in the Landscape

    E-Print Network [OSTI]

    Yun-Song Piao

    2008-06-11T23:59:59.000Z

    In the eternally inflationary background driven by the metastable vacua of the landscape, it is possible that some local quantum fluctuations with the null energy condition violation can be large enough to stride over the barriers among different vacua, so that create some islands full of radiation in new vacua, and then these emergently thermalized islands will enter into the evolution of standard big bang cosmology. In this paper, we calculate the spectrum of curvature perturbation generated during the emergence of island. We find that generally the spectrum obtained is nearly scale invariant, which can be well related to that of slow roll inflation by a simple duality. This in some sense suggests a degeneracy between their scalar spectra. In addition, we also simply estimate the non-Gaussianity of perturbation, which is naturally large, yet, can lie well in the observational bound. The results shown here indicate that the island emergently thermalized in the landscape can be consistent with our observable universe.

  6. The Long Island Solar Farm

    Broader source: Energy.gov [DOE]

    In November 2011, a utility-scale solar array became operational in the most unlikely of places: at Brookhaven National Laboratory on densely populated Long Island, New York. Now the largest...

  7. Chikurachki volcano (Kurile Islands, Russia)

    E-Print Network [OSTI]

    Belousov, Alexander

    Chikurachki volcano (Kurile Islands, Russia) the unique volcano with frequent basaltic plinian-Kamchatsky, Russia #12;#12;Historical eruptions of Chikurachki Year 1853-59 1958 1961 1964 1973 1986 2002 Column

  8. Electronic transport in graphene-based heterostructures

    SciTech Connect (OSTI)

    Tan, J. Y.; Avsar, A.; Balakrishnan, J.; Taychatanapat, T.; O'Farrell, E. C. T.; Eda, G.; Castro Neto, A. H. [Graphene Research Center, National University of Singapore, Singapore 117542 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Koon, G. K. W.; Özyilmaz, B., E-mail: barbaros@nus.edu.sg [Graphene Research Center, National University of Singapore, Singapore 117542 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); NanoCore, National University of Singapore, Singapore 117576 (Singapore); Watanabe, K.; Taniguchi, T. [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2014-05-05T23:59:59.000Z

    While boron nitride (BN) substrates have been utilized to achieve high electronic mobilities in graphene field effect transistors, it is unclear how other layered two dimensional (2D) crystals influence the electronic performance of graphene. In this Letter, we study the surface morphology of 2D BN, gallium selenide (GaSe), and transition metal dichalcogenides (tungsten disulfide (WS{sub 2}) and molybdenum disulfide (MoS{sub 2})) crystals and their influence on graphene's electronic quality. Atomic force microscopy analysis shows that these crystals have improved surface roughness (root mean square value of only ?0.1?nm) compared to conventional SiO{sub 2} substrate. While our results confirm that graphene devices exhibit very high electronic mobility (?) on BN substrates, graphene devices on WS{sub 2} substrates (G/WS{sub 2}) are equally promising for high quality electronic transport (????38?000 cm{sup 2}/V s at room temperature), followed by G/MoS{sub 2} (????10?000 cm{sup 2}/V s) and G/GaSe (????2200 cm{sup 2}/V s). However, we observe a significant asymmetry in electron and hole conduction in G/WS{sub 2} and G/MoS{sub 2} heterostructures, most likely due to the presence of sulphur vacancies in the substrate crystals. GaSe crystals are observed to degrade over time even under ambient conditions, leading to a large hysteresis in graphene transport making it a less suitable substrate.

  9. Extended Supersymmetry in Gapped and Superconducting Graphene

    E-Print Network [OSTI]

    Oikonomou, V K

    2014-01-01T23:59:59.000Z

    In view of the many quantum field theoretical descriptions of graphene in $2+1$ dimensions, we present another field theoretical feature of graphene, in the presence of defects. Particularly, we shall be interested in gapped graphene in the presence of a domain wall and also for superconducting graphene in the presence of a vortex. As we explicitly demonstrate, the gapped graphene electrons that are localized on the domain wall are associated with four $N=2$ one dimensional supersymmetries, with each pair combining to form an extended $N=4$ supersymmetry with non-trivial topological charges. The case of superconducting graphene is more involved, with the electrons localized on the vortex being associated with $n$ one dimensional supersymmetries, which in turn combine to form an $N=2n$ extended supersymmetry with no-trivial topological charges. As we shall prove, all supersymmetries are unbroken, a feature closely related to the number of the localized fermions and also to the exact form of the associated oper...

  10. Graphene: from materials science to particle physics

    E-Print Network [OSTI]

    Joaquín E. Drut; Timo A. Lähde; Eero Tölö

    2010-11-02T23:59:59.000Z

    Since its discovery in 2004, graphene, a two-dimensional hexagonal carbon allotrope, has generated great interest and spurred research activity from materials science to particle physics and vice versa. In particular, graphene has been found to exhibit outstanding electronic and mechanical properties, as well as an unusual low-energy spectrum of Dirac quasiparticles giving rise to a fractional quantum Hall effect when freely suspended and immersed in a magnetic field. One of the most intriguing puzzles of graphene involves the low-temperature conductivity at zero density, a central issue in the design of graphene-based nanoelectronic components. While suspended graphene experiments have shown a trend reminiscent of semiconductors, with rising resistivity at low temperatures, most theories predict a constant or even decreasing resistivity. However, lattice field theory calculations have revealed that suspended graphene is at or near the critical coupling for excitonic gap formation due to strong Coulomb interactions, which suggests a simple and straightforward explanation for the experimental data. In this contribution we review the current status of the field with emphasis on the issue of gap formation, and outline recent progress and future points of contact between condensed matter physics and Lattice QCD.

  11. Extended Supersymmetry in Gapped and Superconducting Graphene

    E-Print Network [OSTI]

    V. K. Oikonomou

    2014-11-30T23:59:59.000Z

    In view of the many quantum field theoretical descriptions of graphene in $2+1$ dimensions, we present another field theoretical feature of graphene, in the presence of defects. Particularly, we shall be interested in gapped graphene in the presence of a domain wall and also for superconducting graphene in the presence of a vortex. As we explicitly demonstrate, the gapped graphene electrons that are localized on the domain wall are associated with four $N=2$ one dimensional supersymmetries, with each pair combining to form an extended $N=4$ supersymmetry with non-trivial topological charges. The case of superconducting graphene is more involved, with the electrons localized on the vortex being associated with $n$ one dimensional supersymmetries, which in turn combine to form an $N=2n$ extended supersymmetry with no-trivial topological charges. As we shall prove, all supersymmetries are unbroken, a feature closely related to the number of the localized fermions and also to the exact form of the associated operators. In addition, the corresponding Witten index is invariant under compact and odd perturbations.

  12. Charge Transfer Properties Through Graphene Layers in Gas Detectors

    E-Print Network [OSTI]

    P. Thuiner; R. Hall-Wilton; R. B. Jackman; H. Müller; T. T. Nguyen; E. Oliveri; D. Pfeiffer; F. Resnati; L. Ropelewski; J. A. Smith; M. van Stenis; R. Veenhof

    2015-03-23T23:59:59.000Z

    Graphene is a single layer of carbon atoms arranged in a honeycomb lattice with remarkable mechanical, electrical and optical properties. For the first time graphene layers suspended on copper meshes were installed into a gas detector equipped with a gaseous electron multiplier. Measurements of low energy electron and ion transfer through graphene were conducted. In this paper we describe the sample preparation for suspended graphene layers, the testing procedures and we discuss the preliminary results followed by a prospect of further applications.

  13. Adsorption on tunable bilayer graphene: A model approach

    SciTech Connect (OSTI)

    Alisultanov, Z. Z., E-mail: zaur0102@gmail.com [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2013-07-15T23:59:59.000Z

    The problem of the adsorption of atoms on the surface of tunable bilayer graphene is considered within the context of Anderson's model. Analytical expressions for the densities of states of bilayer graphene and an adatom are derived, and the charge exchange between adatoms and bilayer graphene is studied. The charge of adatoms of some elements is estimated. The change induced in the density of states of tunable bilayer graphene by the adsorption of atoms is explored.

  14. Thermal conductivity of graphene nanoribbons in noble gaseous environments

    SciTech Connect (OSTI)

    Zhong, Wei-Rong, E-mail: wrzhong@hotmail.com; Xu, Zhi-Cheng; Zheng, Dong-Qin [Department of Physics and Siyuan Laboratory, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Ai, Bao-Quan, E-mail: aibq@scnu.edu.cn [Laboratory of Quantum Information Technology, ICMP and SPTE, South China Normal University, Guangzhou 510006 (China)

    2014-02-24T23:59:59.000Z

    We investigate the thermal conductivity of suspended graphene nanoribbons in noble gaseous environments using molecular dynamics simulations. It is reported that the thermal conductivity of perfect graphene nanoribbons decreases with the gaseous pressure. The decreasing is more obvious for the noble gas with large atomic number. However, the gaseous pressure cannot change the thermal conductivity of defective graphene nanoribbons apparently. The phonon spectra of graphene nanoribbons are also provided to give corresponding supports.

  15. Motivational factors related to beach usage at Galveston Island State Park, Texas

    E-Print Network [OSTI]

    Schwartz, Martin Philip

    2012-06-07T23:59:59.000Z

    Galveston Island State Park like other Texas state parks is dedicated to preserving unique natural environments and providing public outdoor recreation opportunities. Although public beach facilities are available within the Galveston city limits..., 1976. The park's location has helped to contribute to the recreation opportunities of Galveston Island and to protect a natural environment which may have otherwise been destroyed by the encroachment of beach homes or commercial developments. Today...

  16. WHAT'S GRAPHENE? Mono or few layers of sp2 bonded

    E-Print Network [OSTI]

    Mellor-Crummey, John

    WHAT'S GRAPHENE? · Mono or few layers of sp2 bonded carbon atoms in a honeycomb lattice 105cm2/Vs at RT. 1 Due to its unique transport properties, graphene is suitable for implementation sampling (EOS) timeresolved spectroscopy to optically pump and THz probe exfoliated graphene ribbons (GR

  17. Negative quantum capacitance in graphene nanoribbons with lateral gates

    E-Print Network [OSTI]

    Florian, Libisch

    Negative quantum capacitance in graphene nanoribbons with lateral gates R. Reiter1, , U. Derra2 , S numerical simulations of the capacitive coupling between graphene nanoribbons of various widths and gate electrodes in different configurations. We compare the influence of lateral metallic or graphene side gate

  18. Strong Correlation Effects in Graphene in the Quantum Hall Regime

    E-Print Network [OSTI]

    Paris-Sud 11, Université de

    Strong Correlation Effects in Graphene in the Quantum Hall Regime Mark Oliver Goerbig 16 June 2008;Graphene = 2D Graphite 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 degeneracy: spin valley Energy electrons holes k k k ky x x yK' K K' K K K' #12;Correlations in graphene

  19. Room Temperature Metastability of Multilayer Graphene Oxide Films

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Room Temperature Metastability of Multilayer Graphene Oxide Films Suenne Kim1 , Si Zhou2 , Yike Hu1 Centre National de la Recherche Scientifique ­ Institut N´eel, Grenoble, B.P. 166, 38042 France Graphene oxide has multiple potential applications. The chemistry of graphene oxide and its response to external

  20. Electrical Control of Optical Plasmon Resonance with Graphene Jonghwan Kim,

    E-Print Network [OSTI]

    Wang, Feng

    Electrical Control of Optical Plasmon Resonance with Graphene Jonghwan Kim, Hyungmok Son, David J of near- infrared plasmon resonance in a hybrid graphene-gold nanorod system. Exploiting the uniquely strong11,12 and gate-tunable optical transitions13,14 of graphene, we are able to significantly modulate

  1. Disorder scattering in graphene nanoribbons F. Libisch1

    E-Print Network [OSTI]

    Florian, Libisch

    Disorder scattering in graphene nanoribbons F. Libisch1 , S. Rotter1 , J. Burgd¨orfer1 1 Institute investigate transport through bulk-disordered graphene nanoribbons and nanoconstrictions. Employing a modular transforming the scattered wave we disentangle inter-valley scattering between the two Dirac cones of graphene

  2. Slip corona surrounding bilayer graphene nanopore Yunwei Maob

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    Slip corona surrounding bilayer graphene nanopore Liang Qi,a Yunwei Maob and Ju Li*abc Received 5th of bilayer graphene (BLG) depend on the stacking order between the two layers. We introduce a new conceptual and low interlayer shear resistance between two adjacent layers of graphene. The continuum model also

  3. Plasmonics and Electron Optics in Graphene Min Seok Jang

    E-Print Network [OSTI]

    Winfree, Erik

    Plasmonics and Electron Optics in Graphene Thesis by Min Seok Jang In Partial Fulfillment novice. He, Seyoon Kim, Josue Lopez and I have been working as a team on the graphene plasmonics project young scientists in Atwater group. Hyungjun Kim and I have been working on graphene electron optics more

  4. Atom-by-atom nucleation and growth of graphene nanopores

    E-Print Network [OSTI]

    Golovchenko, Jene A.

    Atom-by-atom nucleation and growth of graphene nanopores Christopher J. Russoa,b and J. A February 17, 2012 (received for review December 9, 2011) Graphene is an ideal thin membrane substrate structures in graphene with atomic preci- sion. It consists of inducing defect nucleation centers with ener

  5. Towards intrinsic magnetism of graphene sheets with irregular zigzag edges

    E-Print Network [OSTI]

    Wang, Wei Hua

    Towards intrinsic magnetism of graphene sheets with irregular zigzag edges Lianlian Chen, Liwei Guo Academy of Sciences, P.O. Box 603, Beijing 100190, China. The magnetism of graphene has remained divergent and controversial due to absence of reliable experimental results. Here we show the intrinsic magnetism of graphene

  6. Extending ballistic graphene FET lumped element models to diffusive devices

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Extending ballistic graphene FET lumped element models to diffusive devices G Vincenzi1,2 , G graphene field effect device model is presented. The model is based on the "Top-of-the-barrier" approach which is usually valid only for ballistic graphene nanotransistors. Proper modifications are introduced

  7. NANO EXPRESS Open Access Multiscale investigation of graphene layers on

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    NANO EXPRESS Open Access Multiscale investigation of graphene layers on 6H-SiC(000-1) Antoine , Cecile Naud2 , Jean-Yves Veuillen2* Abstract In this article, a multiscale investigation of few graphene, the authors show that the UHV growth yields few layer graphene (FLG) with an average thickness given by Auger

  8. Growth of graphene on Ir(111) Johann Coraux1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Growth of graphene on Ir(111) Johann Coraux1 ,, Alpha T. N'Diaye1 §, Martin Engler1 , Carsten Busse a renewed interest as a route towards high quality graphene prepared in a reproducible manner. Here we employ two growth methods for graphene on Ir(111), namely room temperature adsorption and thermal

  9. Biaxial Strain in Graphene Adhered to Shallow Depressions

    E-Print Network [OSTI]

    ABSTRACT Measurements on graphene exfoliated over a substrate prepatterned with shallow depressions or adhered to the bottom of a trench. Mechanical exfoliation of natural graphite was employed to transfer used to maximize the optical contrast of graphene on the substrate.11,12 Prior to graphene exfoliation

  10. Direct Imaging of Soft-Hard Interfaces Enabled by Graphene

    E-Print Network [OSTI]

    Frenklach, Michael

    Direct Imaging of Soft-Hard Interfaces Enabled by Graphene Zonghoon Lee,*, Ki-Joon Jeon,*, Albert. We show that graphene, a single atomic layer of sp2 -bonded carbon atoms, can be employed capability. Our findings reveal the unique potential of graphene as an ideal support film for atomic

  11. Thermal Transport in Suspended and Supported Few-Layer Graphene

    E-Print Network [OSTI]

    Li, Baowen

    Thermal Transport in Suspended and Supported Few-Layer Graphene Ziqian Wang,, Rongguo Xie,,,§, Cong few-layer graphene using a thermal-bridge configuration. The room temperature value of is comparable transport of the suspended graphene. The measured values of are generally lower than those from theoretical

  12. Exercice session Cargse, October 2008 Klein tunneling in graphene

    E-Print Network [OSTI]

    Paris-Sud 11, Université de

    Exercice session Cargèse, October 2008 Klein tunneling in graphene Pierre Allain and Jean-Noël Fuchs 1 Introduction : plane wave The goal is to compute the probability transmission T of a graphene 1 = n2 sin 2 for an electron in graphene and show that the optical index n is proportional

  13. Enhanced Half-Metallicity in Edge-Oxidized Zigzag Graphene

    E-Print Network [OSTI]

    Hod, Oded

    Enhanced Half-Metallicity in Edge-Oxidized Zigzag Graphene Nanoribbons Oded Hod,* Vero´nica Barone theoretical study of the electronic properties and relative stabilities of edge-oxidized zigzag graphene with nanometer scale dimen- sions. Recently, a new type of graphene-based material was experimentally realized.12

  14. Pentagonal puckering in a sheet of amorphous graphene

    E-Print Network [OSTI]

    Thorpe, Michael

    Pentagonal puckering in a sheet of amorphous graphene Y. Li 1 , F. Inam 2 , Avishek Kumar 3 , M. F 2011 Published online 13 July 2011 Keywords amorphous graphene, density functional theory, fullerenes Ordered graphene has been extensively studied. In this paper, we undertake a density functional study

  15. Scalable enhancement of graphene oxide properties by thermally driven phase

    E-Print Network [OSTI]

    Wu, Junqiao

    Scalable enhancement of graphene oxide properties by thermally driven phase transformation Priyank,2,4 * and Jeffrey C. Grossman1 * Chemical functionalization of graphene is promising for a variety of next-generation technologies. Although graphene oxide (GO) is a versatile material in this direction, its use is limited

  16. Impermeability of graphene and its applications Vikas Berry *

    E-Print Network [OSTI]

    Berry, Vikas

    Review Impermeability of graphene and its applications Vikas Berry * Department of Chemical T This review discusses the genesis of impermeability in graphene and its extraordinary applications in fluid rusting and environmental hazards. As the thinnest material, graphene is composed of sp2 hybridized carbon

  17. Electronic Structure and Stability of Semiconducting Graphene Nanoribbons

    E-Print Network [OSTI]

    Hod, Oded

    Electronic Structure and Stability of Semiconducting Graphene Nanoribbons Vero´nica Barone, Oded stability of semiconducting graphene nanoribbons. We consider ribbons with different edge nature including band structure of graphene (a single infinite sheet of graphite). Depending on their chirality

  18. Tearing of Free-Standing Graphene M. J. B. Moura

    E-Print Network [OSTI]

    Texas at Austin. University of

    Tearing of Free-Standing Graphene M. J. B. Moura IBM Research - Brazil, Av. Pasteur 138 of tearing graphene. We present a molecular dynamics simulation of the propagation of cracks in clamped, free-standing graphene as a function of the out-of-plane force. The geometry is motivated by experimental configurations

  19. Nanobiosensors Constraint of DNA on Functionalized Graphene Improves

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    Nanobiosensors Constraint of DNA on Functionalized Graphene Improves its Biostability, Jun Liu, and Yuehe Lin* Graphene, a single-layer carbon crystal, is attracting increasing attention strength, and biocompa- tibility.[1a,c,,2] Recently, functionalized graphene has been successfully used

  20. ORNL 2013-G00021/tcc Large Scale Graphene Production

    E-Print Network [OSTI]

    ORNL 2013-G00021/tcc 02.2013 Large Scale Graphene Production UT-B ID 201102606 Technology Summary Graphene is an emerging one-atom-thick carbon material which has the potential for a wide range research, graphene has quickly attained the status of a wonder nanomaterial and continued to draw

  1. Highly Confined Tunable Mid-Infrared Plasmonics in Graphene Nanoresonators

    E-Print Network [OSTI]

    Highly Confined Tunable Mid-Infrared Plasmonics in Graphene Nanoresonators Victor W. Brar,, Min Supporting Information ABSTRACT: Single-layer graphene has been shown to have intriguing prospects observed in the 2-6 THz range, and active graphene plasmonic devices operating in that regime have been

  2. Fine tuning of graphene-metal adhesion by surface alloying

    E-Print Network [OSTI]

    Alfè, Dario

    Fine tuning of graphene-metal adhesion by surface alloying D. Alfe`1,2 , M. Pozzo1 , E. Miniussi3 route for governing the interaction between graphene and metal through the selective choice characterization of the properties of graphene on a model PtRu surface alloy on Ru(0001), with a concentration

  3. Deep subwavelength plasmonic waveguide switch in double graphene layer structure

    E-Print Network [OSTI]

    Fan, Shanhui

    Deep subwavelength plasmonic waveguide switch in double graphene layer structure Hideo Iizuka in double graphene layer structure Hideo Iizuka1,a) and Shanhui Fan2,b) 1 Toyota Central Research December 2013) Graphene provides excellent prospects of the dynamic tunability, low propagation loss

  4. Graphene-enabled Wireless Communication for Massive Multicore Architectures

    E-Print Network [OSTI]

    Cabellos-Aparicio, Albert

    Graphene-enabled Wireless Communication for Massive Multicore Architectures Sergi Abadal, Eduard. This goal is feasible by using graphene-based planar antennas, which can radiate signals at the Terahertz, this is the first work that discusses the utilization of graphene-enabled wireless communication for massive

  5. Graphene growth directly on functional substrate , L. Baratona

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Graphene growth directly on functional substrate C. S. Leea , L. Baratona , Z. B. Hea , J E-mail address: laurent.baraton@polytechnique.edu. Abstract Graphene is perhaps the most promising of the awaited graphene film formed at the surface of catalyst layer, we observed the formation of a second

  6. GRAPHENE RESONATORS FOR MECHANICAL SENSING , S. Najmaei2

    E-Print Network [OSTI]

    Mellor-Crummey, John

    GRAPHENE RESONATORS FOR MECHANICAL SENSING K. Lai1 , Z. Liu2 , S. Najmaei2 , L. Ma2 , J. Lou2 , P Department of Mechanical Engineering & Materials Science, Rice University Graphene's high conductivity, graphene resonators have been shown to have high quality (Q) factors, showing promise for use in force

  7. Graphene-enabled Wireless Networks-on-Chip (Invited Paper)

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    Graphene-enabled Wireless Networks-on-Chip (Invited Paper) Ignacio Llatser, Sergi Abadal, Albert,abadal,amestres,acabello}@ac.upc.edu, eduard.alarcon@upc.edu Abstract--Graphene-enabled Wireless Communications (GWC) advocate for the use of graphene-based plasmonic antennas, or graphennas, which take advantage of the plasmonic properties

  8. Graphene synthesis by ion implantation Slaven Garaj1

    E-Print Network [OSTI]

    Golovchenko, Jene A.

    Page 1 Graphene synthesis by ion implantation Slaven Garaj1 , William Hubbard2 , and J. A We demonstrate an ion implantation method for large-scale synthesis of high quality graphene films with carbon atoms results in the surface growth of graphene films whose average thickness is controlled

  9. Graphene Based Electrochemical Sensors and Biosensors: Yuyan Shao,a

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    Review Graphene Based Electrochemical Sensors and Biosensors: A Review Yuyan Shao,a Jun Wang,a Hong-mail: Yuehe.lin@pnl.gov Received: November 24, 2009 Accepted: December 23, 2009 Abstract Graphene, emerging of functionalization and mass production). This article selectively reviews recent advances in graphene

  10. Graphene synthesis by ion implantation Slaven Garaj,1

    E-Print Network [OSTI]

    Golovchenko, Jene A.

    Graphene synthesis by ion implantation Slaven Garaj,1 William Hubbard,2 and J. A. Golovchenko1,2,a demonstrate an ion implantation method for large-scale synthesis of high quality graphene films with carbon atoms results in the surface growth of graphene films whose average thickness is controlled

  11. Graphene Enhanced Wireless Sensors Taoran Le, Trang Thai, Vasileios Lakafosis,

    E-Print Network [OSTI]

    Tentzeris, Manos

    Graphene Enhanced Wireless Sensors Taoran Le, Trang Thai, Vasileios Lakafosis, Manos Tentzeris utilizing both analog and digital principles. The sensors will utilize Graphene-based thin films integrated. Our thin films are produced from water-based, inkjet printed graphene oxide (GO) on paper

  12. Reversible micromachining locator

    DOE Patents [OSTI]

    Salzer, L.J.; Foreman, L.R.

    1999-08-31T23:59:59.000Z

    This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved. 7 figs.

  13. Reversible micromachining locator

    DOE Patents [OSTI]

    Salzer, Leander J. (Los Alamos, NM); Foreman, Larry R. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved.

  14. PHYSICAL REVIEW B 83, 165433 (2011) Direct observation of a dispersionless impurity band in hydrogenated graphene

    E-Print Network [OSTI]

    Alfè, Dario

    in hydrogenated graphene D. Haberer,1 L. Petaccia,2 M. Farjam,3 S. Taioli,4,5 S. A. Jafari,3,6 A. Nefedov,7 W monolayer graphene (H-graphene). Its occupation can be controlled with the hydrogen amount and allows for tuning of graphene's doping level. Our calculations of the electronic structure of H-graphene suggest

  15. Electronic structure and quantum transport properties of trilayers formed from graphene and boron nitride

    E-Print Network [OSTI]

    Pandey, Ravi

    Electronic structure and quantum transport properties of trilayers formed from graphene and boron of a theoretical study of graphene/BN/graphene and BN/graphene/BN trilayers using the van systems formed from graphene and BN exhibit distinct stacking-dependent features in their ground state

  16. Renormalization group aspects of graphene

    E-Print Network [OSTI]

    Maria A. H. Vozmediano

    2010-10-25T23:59:59.000Z

    Graphene is a two dimensional crystal of carbon atoms with fascinating electronic and morphological properties. The low energy excitations of the neutral, clean system are described by a massless Dirac Hamiltonian in (2+1) dimensions which also captures the main electronic and transport properties. A renormalization group analysis sheds light on the success of the free model: due to the special form of the Fermi surface which reduces to two single points in momentum space, short range interactions are irrelevant and only gauge interactions like long range Coulomb or effective disorder can play a role in the low energy physics. We review these features and discuss briefly other aspects related to disorder and to the bilayer material along the same lines.

  17. Optical conductivity of curved graphene

    E-Print Network [OSTI]

    A. J. Chaves; T. Frederico; O. Oliveira; W. de Paula; M. C. Santos

    2014-05-01T23:59:59.000Z

    We compute the optical conductivity for an out-of-plane deformation in graphene using an approach based on solutions of the Dirac equation in curved space. Different examples of periodic deformations along one direction translates into an enhancement of the optical conductivity peaks in the region of the far and mid infrared frequencies for periodicities $\\sim100\\,$nm. The width and position of the peaks can be changed by dialling the parameters of the deformation profiles. The enhancement of the optical conductivity is due to intraband transitions and the translational invariance breaking in the geometrically deformed background. Furthemore, we derive an analytical solution of the Dirac equation in a curved space for a general deformation along one spatial direction. For this class of geometries, it is shown that curvature induces an extra phase in the electron wave function, which can also be explored to produce interference devices of the Aharonov-Bohm type.

  18. Holographic Graphene in a Cavity

    E-Print Network [OSTI]

    Nick Evans; Peter A. R. Jones

    2014-07-11T23:59:59.000Z

    The effective strength of EM interactions can be controlled by confining the fields to a cavity and these effects might be used to push graphene into a strongly coupled regime. We study the similar D3/probe D5 system on a compact space and discuss the gravity dual for a cavity between two mirrors. We show that the introduction of a conformal symmetry breaking length scale introduces a mass gap on a single D5 sheet. Bilayer configurations display exciton condensation between the sheets. There is a first order phase transition away from the exciton condensate if a strong enough magnetic field is applied. We finally map out the phase structure of these systems in a cavity with the presence of mirror reflections of the probes - a mass gap may form through exciton condensation with the mirror image.

  19. Reversible micromachining locator

    DOE Patents [OSTI]

    Salzer, Leander J. (Los Almos, NM); Foreman, Larry R. (late of Los Alamos, NM)

    2002-01-01T23:59:59.000Z

    A locator with a part support is used to hold a part onto the kinematic mount of a tooling machine so that the part can be held in or replaced in exactly the same position relative to the cutting tool for machining different surfaces of the part or for performing different machining operations on the same or different surfaces of the part. The locator has disposed therein a plurality of steel balls placed at equidistant positions around the planar surface of the locator and the kinematic mount has a plurality of magnets which alternate with grooves which accommodate the portions of the steel balls projecting from the locator. The part support holds the part to be machined securely in place in the locator. The locator can be easily detached from the kinematic mount, turned over, and replaced onto the same kinematic mount or another kinematic mount on another tooling machine without removing the part to be machined from the locator so that there is no need to touch or reposition the part within the locator, thereby assuring exact replication of the position of the part in relation to the cutting tool on the tooling machine for each machining operation on the part.

  20. Site response at Treasure and Yerba Buena Islands, California

    E-Print Network [OSTI]

    Baise, L G; Glaser, Steven D; Dreger, D

    2003-01-01T23:59:59.000Z

    array at the Treasure Island Naval Station. ’’ Loma Prietadamage in Oakland, Treasure Island, and San Francisco. ’’C. H. ?1969?. ‘‘Treasure Island ?ll. ’’ Bay mud developments

  1. Detection of nucleic acids by graphene-based devices: A first-principles study

    SciTech Connect (OSTI)

    Zhang, Hua [School of Physics and Electronics, Central South University, Changsha 410083 (China); School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114 (China); Xu, Hui, E-mail: xuhui@csu.edu.cn, E-mail: ouyangfp06@tsinghua.org.cn; Ni, Xiang; Lin Peng, Sheng; Liu, Qi; Ping OuYang, Fang, E-mail: xuhui@csu.edu.cn, E-mail: ouyangfp06@tsinghua.org.cn [School of Physics and Electronics, Central South University, Changsha 410083 (China)

    2014-04-07T23:59:59.000Z

    Based on first-principles quantum transport calculations, we design a graphene-based biosensor device, which is composed of graphene nanoribbons electrodes and a biomolecule. It is found that when different nucleobases or poly nucleobase chains are located in the nanogap, the device presents completely different transport properties, showing different current informations. And the change of currents from 2 to 5 orders of magnitude for four different nucleobases suggests a great ability of discrimination by utilizing such a device. The physical mechanism of this phenomenon originates from their different chemical composition and structure. Moreover, we also explore the coupling effect of several neighboring bases and the size effect of the nanogap on transport properties. Our results show the possibility of rapid sequencing DNA by measuring such a transverse-current of the device, and provide a new idea for sequencing DNA.

  2. A molecular dynamics study of polymer/graphene interfacial systems

    SciTech Connect (OSTI)

    Rissanou, Anastassia N.; Harmandaris, Vagelis [Department of Mathematics and Applied Mathematics, University of Crete, GR-71409, Heraklion, Crete, Greece and Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas (FORTH), GR-71110, Heraklion, Cret (Greece)

    2014-05-15T23:59:59.000Z

    Graphene based polymer nanocomposites are hybrid materials with a very broad range of technological applications. In this work, we study three hybrid polymer/graphene interfacial systems (polystyrene/graphene, poly(methyl methacrylate)/graphene and polyethylene/graphene) through detailed atomistic molecular dynamics (MD) simulations. Density profiles, structural characteristics and mobility aspects are being examined at the molecular level for all model systems. In addition, we compare the properties of the hybrid systems to the properties of the corresponding bulk ones, as well as to theoretical predictions.

  3. Field emission characteristics from graphene on hexagonal boron nitride

    SciTech Connect (OSTI)

    Yamada, Takatoshi, E-mail: takatoshi-yamada@aist.go.jp [National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Masuzawa, Tomoaki; Ebisudani, Taishi; Okano, Ken [International Christian University, 3-10-2 Osawa, Mitaka, Tokyo 181-8585 (Japan); Taniguchi, Takashi [National Institute for Material Science (NIMS), 1-1-1 Namiki, Tsukuba 305-0044 (Japan)

    2014-06-02T23:59:59.000Z

    An attempt has been made to utilize uniquely high electron mobility of graphene on hexagonal boron nitride (h-BN) to electron emitter. The field emission property of graphene/h-BN/Si structure has shown enhanced threshold voltage and emission current, both of which are key to develop novel vacuum nanoelectronics devices. The field emission property was discussed along with the electronic structure of graphene investigated by Fowler-Nordheim plot and ultraviolet photoelectron spectroscopy. The result suggested that transferring graphene on h-BN modified its work function, which changed field emission mechanism. Our report opens up a possibility of graphene-based vacuum nanoelectronics devices with tuned work function.

  4. http: www. wuli. ac. cn / 38 (2009~OE) 6 Graphene~ -- ... ^

    E-Print Network [OSTI]

    Gao, Hongjun

    Graphene~ --° º ... ^ 3 ÷ ± ... ÷ (--,,oe¿ § " --¿ ¸ø ¡¡~ ^ º ...° � ° ¡¡­­' ¡¡ 100190) " ¡¡ " ¡¡ ¡¡ Graphene --´ ~ --° " ,,ª ·" ~ ^ , ¸ " ,,oe...°--´~ ` ` ~ --¿ " ¨¨ ª . ~ ´ OE , � `¸ Graphene `¸ ° . ,, ...·° ¡¡ ¡¡ Graphene, `¿ » ¶�--§ , -- § , ... Physical properties and application of Graphene MAO Jin2Hai¡¡ ¡¡ ZHANG

  5. Nanoscale topographical replication of graphene architecture by artificial DNA nanostructures

    SciTech Connect (OSTI)

    Moon, Y.; Seo, S.; Park, J.; Park, T.; Ahn, J. R., E-mail: jrahn@skku.edu [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Shin, J.; Dugasani, S. R. [Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Woo, S. H. [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Park, S. H., E-mail: sunghapark@skku.edu [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-06-09T23:59:59.000Z

    Despite many studies on how geometry can be used to control the electronic properties of graphene, certain limitations to fabrication of designed graphene nanostructures exist. Here, we demonstrate controlled topographical replication of graphene by artificial deoxyribonucleic acid (DNA) nanostructures. Owing to the high degree of geometrical freedom of DNA nanostructures, we controlled the nanoscale topography of graphene. The topography of graphene replicated from DNA nanostructures showed enhanced thermal stability and revealed an interesting negative temperature coefficient of sheet resistivity when underlying DNA nanostructures were denatured at high temperatures.

  6. Transport, Aharonov-Bohm, and Topological Effects in Graphene Molecular Junctions and Graphene Nanorings

    E-Print Network [OSTI]

    Constantine Yannouleas; Igor Romanovsky; Uzi Landman

    2015-02-16T23:59:59.000Z

    The unique ultra-relativistic, massless, nature of electron states in two-dimensional extended graphene sheets, brought about by the honeycomb lattice arrangement of carbon atoms in two-dimensions, provides ingress to explorations of fundamental physical phenomena in graphene nanostructures. Here we explore the emergence of new behavior of electrons in atomically precise segmented graphene nanoribbons (GNRs) and graphene rings with the use of tight-binding calculations, non-equilibrium Green's function transport theory, and a newly developed Dirac continuum model that absorbs the valence-to-conductance energy gaps as position-dependent masses, including topological-in-origin mass-barriers at the contacts between segments. Through transport investigations in variable-width segmented GNRs with armchair, zigzag, and mixed edge terminations we uncover development of new Fabry-Perot-like interference patterns in segmented GNRs, a crossover from the ultra-relativistic massless regime, characteristic of extended graphene systems, to a massive relativistic behavior in narrow armchair GNRs, and the emergence of nonrelativistic behavior in zigzag-terminated GNRs. Evaluation of the electronic states in a polygonal graphene nanoring under the influence of an applied magnetic field in the Aharonov-Bohm regime, and their analysis with the use of a relativistic quantum-field theoretical model, unveils development of a topological-in-origin zero-energy soliton state and charge fractionization. These results provide a unifying framework for analysis of electronic states, coherent transport phenomena, and the interpretation of forthcoming experiments in segmented graphene nanoribbons and polygonal rings.

  7. Thermodynamic properties of a magnetically modulated graphene

    E-Print Network [OSTI]

    SK Firoz Islam; Naveen K. Singh; Tarun Kanti Ghosh

    2011-09-12T23:59:59.000Z

    The effect of magnetic modulation on thermodynamic properties of a graphene monolayer in presence of a constant perpendicular magnetic field is reported here. One-dimensional spatial electric or magnetic modulation lifts the degeneracy of the Landau levels and converts into bands and their band width oscillates with magnetic field leading to Weiss-type oscillation in the thermodynamic properties. The effect of magnetic modulation on thermodynamic properties of a graphene sheet is studied and then compared with electrically modulated graphene and magnetically modulated conventional two-dimensional electron gas (2DEG). We observe Weiss-type and de Haas-van Alphen (dHvA) oscillations at low and high magnetic field, respectively. There is a definite phase difference in Weiss-type oscillations in thermodynamic quantities of magnetically modulated graphene in compare to electrically modulated graphene. On the other hand, the phase remains same and amplitude of the oscillation is large when compared with the magnetically modulated 2DEG. Explicit asymptotic expressions of density of states and the Helmholtz free energy are provided to understand the phase and amplitude of the Weiss-type oscillations qualitatively. We also study thermodynamic properties when both electric and magnetic modulations are present. The Weiss-type oscillations still exist when the modulations are out-of-phase.

  8. Graphene-based qubits in quantum communications

    E-Print Network [OSTI]

    G. Y. Wu; N. -Y. Lue

    2012-07-09T23:59:59.000Z

    We explore the potential application of graphene-based qubits in photonic quantum communications. In particular, the valley pair qubit in double quantum dots of gapped graphene is investigated as a quantum memory in the implementation of quantum repeaters. For the application envisioned here, our work extends the recent study of the qubit (Wu et al., arXiv: 1104.0443; Phys. Rev. B 84, 195463 (2011)) to the case where the qubit is placed in a normal magnetic field-free configuration. It develops, for the configuration, a method of qubit manipulation, based on a unique AC electric field-induced, valley-orbit interaction-derived mechanism in gapped graphene. It also studies the optical response of graphene quantum dots in the configuration, in terms of valley excitation with respect to photonic polarization, and illustrates faithful photon \\leftrightarrow valley quantum state transfers. This work suggests the interesting prospect of an all-graphene approach for the solid state components of a quantum network, e.g., quantum computers and quantum memories in communications.

  9. Weyl-Gauge Symmetry of Graphene

    E-Print Network [OSTI]

    Alfredo Iorio

    2011-01-19T23:59:59.000Z

    The conformal invariance of the low energy limit theory governing the electronic properties of graphene is explored. In particular, it is noted that the massless Dirac theory in point enjoys local Weyl symmetry, a very large symmetry. Exploiting this symmetry in the two spatial dimensions and in the associated three dimensional spacetime, we find the geometric constraints that correspond to specific shapes of the graphene sheet for which the electronic density of states is the same as that for planar graphene, provided the measurements are made in accordance to the inner reference frame of the electronic system. These results rely on the (surprising) general relativistic-like behavior of the graphene system arising from the combination of its well known special relativistic-like behavior with the less explored Weyl symmetry. Mathematical structures, such as the Virasoro algebra and the Liouville equation, naturally arise in this three-dimensional context and can be related to specific profiles of the graphene sheet. Speculations on possible applications of three-dimensional gravity are also proposed.

  10. Dirac charge dynamics in graphene by infrared spectroscopy

    SciTech Connect (OSTI)

    Martin, Michael C; Li, Z.Q.; Henriksen, E.A.; Jiang, Z.; Hao, Z.; Martin, Michael C; Kim, P.; Stormer, H.L.; Basov, Dimitri N.

    2008-04-29T23:59:59.000Z

    A remarkable manifestation of the quantum character of electrons in matter is offered by graphene, a single atomic layer of graphite. Unlike conventional solids where electrons are described with the Schrödinger equation, electronic excitations in graphene are governed by the Dirac hamiltonian. Some of the intriguing electronic properties of graphene, such as massless Dirac quasiparticles with linear energy-momentum dispersion, have been confirmed by recent observations. Here, we report an infrared spectromicroscopy study of charge dynamics in graphene integrated in gated devices. Our measurements verify the expected characteristics of graphene and, owing to the previously unattainable accuracy of infrared experiments, also uncover significant departures of the quasiparticle dynamics from predictions made for Dirac fermions in idealized, free-standing graphene. Several observations reported here indicate the relevance of many-body interactions to the electromagnetic response of graphene.

  11. Enhanced optical limiting effects of graphene materials in polyimide

    SciTech Connect (OSTI)

    Gan, Yao; Feng, Miao; Zhan, Hongbing, E-mail: hbzhan@fzu.edu.cn [College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108 (China)

    2014-04-28T23:59:59.000Z

    Three different graphene nanostructure suspensions of graphene oxide nanosheets (GONSs), graphene oxide nanoribbons (GONRs), and graphene oxide quantum dots (GOQDs) are prepared and characterized. Using a typical two-step method, the GONSs, GONRs, and GOQDs are incorporated into a polyimide (PI) matrix to synthesize graphene/PI composite films, whose nonlinear optical (NLO) and optical limiting (OL) properties are investigated at 532?nm in the nanosecond regime. The GONR suspension exhibits superior NLO and OL effects compared with those of GONSs and GOQDs because of its stronger nonlinear scattering and excited-state absorption. The graphene/PI composite films exhibit NLO and OL performance superior to that of their corresponding suspensions, which is attributed primarily to a combination of nonlinear mechanisms, charge transfer between graphene materials and PI, and the matrix effect.

  12. Anomalous behaviour of magnetic coercivity in graphene oxide and reduced graphene oxide

    SciTech Connect (OSTI)

    Bagani, K.; Bhattacharya, A.; Kaur, J.; Rai Chowdhury, A.; Ghosh, B.; Banerjee, S., E-mail: sangam.banerjee@saha.ac.in [Saha Institute of Nuclear Physics, Surface Physics Division, 1/AF Bidhannagar, Kolkata 700064 (India); Sardar, M. [Material Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2014-01-14T23:59:59.000Z

    In this report, we present the temperature dependence of the magnetic coercivity of graphene oxide (GO) and reduced graphene oxide (RGO). We observe an anomalous decrease in coercivity of GO and RGO with decreasing temperature. The observation could be understood by invoking the inherent presence of wrinkles on graphene oxide due to presence of oxygen containing groups. Scanning electron microscopic image reveals high wrinkles in GO than RGO. We observe higher coercivity in RGO than in GO. At room temperature, we observe antiferromagnetic and ferromagnetic behaviours in GO and RGO, respectively. Whereas, at low temperatures (below T?=?60–70?K), both materials show paramagnetic behaviour.

  13. Sustainable Development and Kish Island Environment Protection, using Wind Energy

    E-Print Network [OSTI]

    Amir Gandomkar

    Abstract—Kish Islands in South of Iran is located in coastal water near Hormozgan Province. Based on the wind 3-hour statistics in Kish station, the mean annual windspeed in this Island is 8.6 knot (4.3 m/s). The maximum windspeed recorded in this stations 47 knot (23.5 m/s). In 45.7 percent of recorded times, windspeed has been Zero or less than 8 knot which is not suitable to use the wind energy. But in 54.3 percent of recorded times, windspeed has been more than 8 knot and suitable to use wind energy to run turbines. In 40.2 percent of recorded times, windspeed has been between 8 to 16 knot, in 13 percent of times between 16 to 24 knot and in 1 percent of times it has been higher than 24 knot. In this station, the direction of winds higher than 8 is west and wind direction in Kish station is stable in most times of the year.With regard to high – speed and stable direction winds during the year and also shallow coasts near this is land, it is possible to build offshore wind farms near Kish Island and utilize wind energy produce the electricity required in this Island during most of the year.

  14. Locating Heat Recovery Opportunities

    E-Print Network [OSTI]

    Waterland, A. F.

    1981-01-01T23:59:59.000Z

    Basic concepts of heat recovery are defined as they apply to the industrial community. Methods for locating, ranking, and developing heat recovery opportunities are presented and explained. The needs for useful heat 'sinks' are emphasized as equal...

  15. International land rig locator

    SciTech Connect (OSTI)

    Not Available

    1984-03-01T23:59:59.000Z

    Mechanical specifications, ratings, locations, and status are listed for each of the 5,000 contract rotary drilling rigs operated by the more than 700 independent drilling contractors throughout the Free World.

  16. International land rig locator

    SciTech Connect (OSTI)

    Not Available

    1983-09-01T23:59:59.000Z

    Mechanical specifications, ratings, locations, and status are listed for each of the 5,000 contract rotary drilling rigs operated by more than 700 independent drilling contractors throughout the Free World.

  17. Location linked information

    E-Print Network [OSTI]

    Mankins, Matthew William David, 1975-

    2003-01-01T23:59:59.000Z

    This work builds an infrastructure called Location Linked Information that offers a means to associate digital information with public, physical places. This connection creates a hybrid virtual/physical space, called glean ...

  18. Graphene flakes with defective edge terminations: Universal and topological aspects, and one-dimensional quantum behavior

    E-Print Network [OSTI]

    Yannouleas, Constantine

    Graphene flakes with defective edge terminations: Universal and topological aspects, and one graphene nanoflakes with reconstructed zigzag edges, where a succes- sion of pentagons and heptagons these spectra. The electronic spectra of trigonal graphene nanoflakes with reczag edge terminations exhibit

  19. PHYSICAL REVIEW B 86, 165440 (2012) Graphene flakes with defective edge terminations: Universal and topological aspects,

    E-Print Network [OSTI]

    Yannouleas, Constantine

    2012-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 86, 165440 (2012) Graphene flakes with defective edge terminations: Universal (as a function of the magnetic field) are presented for trigonal graphene nanoflakes. The electronic spectra of trigonal graphene nanoflakes with reczag edge terminations exhibit certain unique

  20. Surface-Enhanced Raman Scattering Study on Graphene-Coated Metallic Nanostructure Substrates

    E-Print Network [OSTI]

    #12;Surface-Enhanced Raman Scattering Study on Graphene-Coated Metallic Nanostructure Substrates University, University Park, Pennsylvania 16802, United States *S Supporting Information ABSTRACT: Graphene, we combine graphene with conventional metallic surface- enhanced Raman scattering (SERS) substrates

  1. Surface Modifications of Graphene-based Polymer Nanocomposites by Different Synthesis Techniques

    E-Print Network [OSTI]

    Yanikoglu, Berrin

    Surface Modifications of Graphene-based Polymer Nanocomposites by Different Synthesis Techniques, polymerization #12;Surface Modifications of Graphene-based Polymer Nanocomposites by Different Synthesis, Turkey ABSTRACT With the appropriate surface treatments, graphene sheets can be separated from graphite

  2. Multifunctionality and control of the crumpling and unfolding of large-area graphene

    E-Print Network [OSTI]

    Zang, Jianfeng

    Crumpled graphene films are widely used, for instance in electronics, energy storage, composites and biomedicine. Although it is known that the degree of crumpling affects graphene’s properties and the performance of ...

  3. Writable graphene: Breaking sp2 bonds with soft X-rays

    E-Print Network [OSTI]

    Zhou, S.

    2010-01-01T23:59:59.000Z

    e?ect and Berry’s phase in graphene. Nature 438, 201-204 (struc- ture of suspended graphene sheets. Nature 446, 60 (structure investigation of graphene. Phys. Rev. Lett. 101,

  4. Prospects of graphene electrodes in photovoltaics Yasin Khatami, Wei Liu, Jiahao Kang, and Kaustav Banerjee*

    E-Print Network [OSTI]

    Prospects of graphene electrodes in photovoltaics Yasin Khatami, Wei Liu, Jiahao Kang, and Kaustav, the prospects of graphene for transparent conductors in photovoltaics are discussed. The recent advancements in a controllable manner. Keywords: Graphene, photovoltaics, transparent conductor 1. INTRODUCTION Transparent

  5. Development of a Scanning Probe Microscope and Studies of Graphene Grown on Copper

    E-Print Network [OSTI]

    Rasool, Haider Imad

    2012-01-01T23:59:59.000Z

    of Graphene Grown on Copper (100) Single Crystals,” JournalGraphene on Polycrystalline Copper,” Nano Letters 11, 251 (5 GRAPHENE GROWTH ON COPPER (100) SINGLE CRYSTALS 5.1

  6. Single- and few-layer graphene by ambient pressure chemical vapor deposition on nickel

    E-Print Network [OSTI]

    Reina Ceeco, Alfonso

    2010-01-01T23:59:59.000Z

    An ambient pressure chemical vapor deposition (APCVD) process is used to fabricate graphene based films consisting of one to several graphene layers across their area. Polycrystalline Ni thin films are used and the graphene ...

  7. Graphene-on-Insulator Transistors Made Using C on Ni Chemical-Vapor Deposition

    E-Print Network [OSTI]

    Keast, Craig L.

    Graphene transistors are made by transferring a thin graphene film grown on Ni onto an insulating SiO[subscript 2] substrate. The properties and integration of these graphene-on-insulator transistors are presented and ...

  8. Free-standing graphene membranes on glass nanopores for ionic current measurements

    E-Print Network [OSTI]

    Walker, Michael I.; Weatherup, Robert S.; Bell, Nicholas A. W.; Hofmann, Stephan; Keyser, Ulrich F.

    2015-01-16T23:59:59.000Z

    A method is established to reliably suspend graphene monolayers across glass nanopores as a simple, low cost platform to study ionic transport through graphene membranes. We systematically show that the graphene seals glass nanopore openings...

  9. Graphene-based Material Systems for Nanoelectronics and Energy Storage Devices

    E-Print Network [OSTI]

    Guo, Shirui

    2012-01-01T23:59:59.000Z

    of High-Quality and Uniform Graphene Films on Copper Foils"and grain boundaries in graphene grown by chemical vapourin patterned epitaxial graphene" Science 2006, 312, 1191. D.

  10. Comparison of gold- and graphene-based resonant nanostructures for terahertz metamaterials and an ultrathin graphene-based modulator

    SciTech Connect (OSTI)

    Shen, Nian-Hai [Ames Laboratory; Tassin, Philippe [Ames Laboratory; Koschny, Thomas [Ames Laboratory; Soukoulis, Costas M [Ames Laboratory

    2014-09-01T23:59:59.000Z

    Graphene exhibits unique material properties, and in electromagnetic wave technology it raises the prospect of devices miniaturized down to the atomic length scale. Here we study split-ring resonator metamaterials made from graphene and we compare them to gold-based metamaterials. We find that graphene's huge reactive response derived from its large kinetic inductance allows for deeply subwavelength resonances, although its resonance strength is reduced due to higher dissipative loss damping and smaller dipole coupling. Nevertheless, tightly stacked graphene rings may provide for negative permeability and the electric dipole resonance of graphene meta-atoms turns out to be surprisingly strong. Based on these findings, we present a terahertz modulator based on a metamaterial with a multilayer stack of alternating patterned graphene sheets separated by dielectric spacers. Neighboring graphene flakes are biased against each other, resulting in modulation depths of over 75% at a transmission level of around 90%.

  11. Chiral tunneling in single and bilayer graphene

    E-Print Network [OSTI]

    T. Tudorovskiy; K. J. A. Reijnders; M. I. Katsnelson

    2011-06-15T23:59:59.000Z

    We review chiral (Klein) tunneling in single-layer and bilayer graphene and present its semiclassical theory, including the Berry phase and the Maslov index. Peculiarities of the chiral tunneling are naturally explained in terms of classical phase space. In a one-dimensional geometry we reduced the original Dirac equation, describing the dynamics of charge carriers in the single layer graphene, to an effective Schr\\"odinger equation with a complex potential. This allowed us to study tunneling in details and obtain analytic formulas. Our predictions are compared with numerical results. We have also demonstrated that, for the case of asymmetric n-p-n junction in single layer graphene, there is total transmission for normal incidence only, side resonances are suppressed.

  12. Intrinsic Spin-Orbit Interaction in Graphene

    E-Print Network [OSTI]

    B. S. Kandemir

    2012-05-03T23:59:59.000Z

    In graphene, we report the first theoretical demonstration of how the intrinsic spin orbit interaction can be deduced from the theory and how it can be controlled by tuning a uniform magnetic field, and/or by changing the strength of a long range Coulomb like impurity (adatom), as well as gap parameter. In the impurity context, we find that intrinsic spin-orbit interaction energy may be enhanced by increasing the strength of magnetic field and/or by decreasing the band gap mass term. Additionally, it may be strongly enhanced by increasing the impurity strength. Furthermore, from the proposal of Kane and Mele [Phys. Rev. Lett. 95, 226801 (2005)], it was discussed that the pristine graphene has a quantized spin Hall effect regime where the Rashba type spin orbit interaction term is smaller than that of intrinsic one. Our analysis suggest the nonexistence of such a regime in the ground state of flat graphene.

  13. Lattice field theory simulations of graphene

    E-Print Network [OSTI]

    Joaquín E. Drut; Timo A. Lähde

    2009-01-06T23:59:59.000Z

    We discuss the Monte Carlo method of simulating lattice field theories as a means of studying the low-energy effective theory of graphene. We also report on simulational results obtained using the Metropolis and Hybrid Monte Carlo methods for the chiral condensate, which is the order parameter for the semimetal-insulator transition in graphene, induced by the Coulomb interaction between the massless electronic quasiparticles. The critical coupling and the associated exponents of this transition are determined by means of the logarithmic derivative of the chiral condensate and an equation-of-state analysis. A thorough discussion of finite-size effects is given, along with several tests of our calculational framework. These results strengthen the case for an insulating phase in suspended graphene, and indicate that the semimetal-insulator transition is likely to be of second order, though exhibiting neither classical critical exponents, nor the predicted phenomenon of Miransky scaling.

  14. Graphene transparency in weak magnetic fields

    E-Print Network [OSTI]

    Valenzuela, David; Loewe, Marcelo; Raya, Alfredo

    2014-01-01T23:59:59.000Z

    We carry out an explicit calculation of the vacuum polarization tensor for an effective low-energy model of monolayer graphene in the presence of a weak magnetic field of intensity $B$ perpendicularly aligned to the membrane. By expanding the quasiparticle propagator in the Schwinger proper time representation up to order $(eB)^2$, where $e$ is the unit charge, we find an explicitly transverse tensor, consistent with gauge invariance. Furthermore, assuming that graphene is radiated with monochromatic light of frequency $\\omega$ along the external field direction, from the modified Maxwell's equations we derive the intensity of transmitted light and the angle of polarization rotation in terms of the longitudinal ($\\sigma_{xx}$) and transverse ($\\sigma_{xy}$) conductivities. Corrections to these quantities, both calculated and measured, are of order $(eB)^2/\\omega^4$. Our findings generalize and complement previously known results reported in literature regarding the light absorption problem in graphene from th...

  15. Semimetalic graphene in a modulated electric potential

    E-Print Network [OSTI]

    J. H. Ho; Y. H. Chiu; S. J. Tsai; M. F. Lin

    2008-09-09T23:59:59.000Z

    The $\\pi$-electronic structure of graphene in the presence of a modulated electric potential is investigated by the tight-binding model. The low-energy electronic properties are strongly affected by the period and field strength. Such a field could modify the energy dispersions, destroy state degeneracy, and induce band-edge states. It should be noted that a modulated electric potential could make semiconducting graphene semimetallic, and that the onset period of such a transition relies on the field strength. There exist infinite Fermi-momentum states in sharply contrast with two crossing points (Dirac points) for graphene without external fields. The finite density of states (DOS) at the Fermi level means that there are free carriers, and, at the same time, the low DOS spectrum exhibits many prominent peaks, mainly owing to the band-edge states.

  16. Resonant Visible Light Modulation with Graphene

    E-Print Network [OSTI]

    Yu, Renwen; de Abajo, F Javier Garcia

    2015-01-01T23:59:59.000Z

    Fast modulation and switching of light at visible and near-infrared (vis-NIR) frequencies is of utmost importance for optical signal processing and sensing technologies. No fundamental limit appears to prevent us from designing wavelength-sized devices capable of controlling the light phase and intensity at gigaherts (and even terahertz) speeds in those spectral ranges. However, this problem remains largely unsolved, despite recent advances in the use of quantum wells and phase-change materials for that purpose. Here, we explore an alternative solution based upon the remarkable electro-optical properties of graphene. In particular, we predict unity-order changes in the transmission and absorption of vis-NIR light produced upon electrical doping of graphene sheets coupled to realistically engineered optical cavities. The light intensity is enhanced at the graphene plane, and so is its absorption, which can be switched and modulated via Pauli blocking through varying the level of doping. Specifically, we explor...

  17. Graphene as a Lattice Field Theory

    E-Print Network [OSTI]

    Simon Hands; Wes Armour; Costas Strouthos

    2015-01-08T23:59:59.000Z

    We introduce effective field theories for the electronic properties of graphene in terms of relativistic fermions propagating in 2+1 dimensions, and outline how strong inter-electron interactions may be modelled by numerical simulation of a lattice field theory. For strong enough coupling an insulating state can form via condensation of particle-hole pairs, and it is demonstrated that this is a theoretical possibility for monolayer graphene. For bilayer graphene the effect of an interlayer bias voltage can be modelled by the introduction of a chemical potential (akin to isopsin chemical potential in QCD) with no accompanying sign problem; simulations reveal the presence of strong interactions among the residual degrees of freedom at the resulting Fermi surface, which is disrupted by an excitonic condensate. We also present preliminary results for the quasiparticle dispersion, which permit direct estimates of both the Fermi momentum and the induced gap.

  18. Graphene as a Lattice Field Theory

    E-Print Network [OSTI]

    Hands, Simon; Strouthos, Costas

    2015-01-01T23:59:59.000Z

    We introduce effective field theories for the electronic properties of graphene in terms of relativistic fermions propagating in 2+1 dimensions, and outline how strong inter-electron interactions may be modelled by numerical simulation of a lattice field theory. For strong enough coupling an insulating state can form via condensation of particle-hole pairs, and it is demonstrated that this is a theoretical possibility for monolayer graphene. For bilayer graphene the effect of an interlayer bias voltage can be modelled by the introduction of a chemical potential (akin to isopsin chemical potential in QCD) with no accompanying sign problem; simulations reveal the presence of strong interactions among the residual degrees of freedom at the resulting Fermi surface, which is disrupted by an excitonic condensate. We also present preliminary results for the quasiparticle dispersion, which permit direct estimates of both the Fermi momentum and the induced gap.

  19. REAP Islanded Grid Wind Power Conference

    Broader source: Energy.gov [DOE]

    Hosted by Renewable Energy Alaska Project, this three-day conference will show attendees how to learn, network, and share information on wind systems in island and islanded grid environments through expert panel discussions, stakeholder dialogue, and training.

  20. Rhode Island Renewable Energy Fund (RIREF)

    Broader source: Energy.gov [DOE]

    Rhode Island's Public Utilities Restructuring Act of 1996 created the nation's first public benefits fund (PBF) for renewable energy and demand-side management (DSM). The Rhode Island Renewable...

  1. Coastal mesoscale changes on Matagorda Island

    E-Print Network [OSTI]

    Lariscy, Kevin William

    2001-01-01T23:59:59.000Z

    on the coastal geomorphology of Matagorda Island. Based on the statistical and morphometric analysis of the coastal landforms, the island was divided into three distinct sub-environments: an erosional eastern zone, a transitional mixed zone, and a depositional...

  2. Preliminary design of a landfill and revetment on Bikini Island, Republic of the Marshall Islands. Final report

    SciTech Connect (OSTI)

    Smith, O.P.; Chu, Y.H.

    1987-02-01T23:59:59.000Z

    Topsoil on Bikini Island, located 2,500 miles southwest of Hawaii at 113 deg 35 min N, 165 deg 25 min E, was contaminated by radioactive fallout from nuclear weapons tests in the late 1940's and early 1950's. The uptake of this radioactive fallout, primarily cesium-137 in plants, has prevented resettlement of the island by the native population. One alternative solution proposed by the congressionally appointed Bikini Atoll Rehabilitation Committee involves removal of the contaminated topsoil and placement of the excavated material as a landfill on the 2,500-ft-wide reef flat adjacent to the eastern (windward) shore of the island. This paper explores that alternative by first developing an extremal wave climatology offshore of Bikini Island from 21 years (1959-1979) of typhoon data published by the Joint Typhoon Warning Center on Guam. Deepwater wave conditions just offshore of the reef are estimated and transformed to the point of breaking at the edge of the reef. Storm surge is estimated based on these same parameters. Wave setup on the reef flat is estimated based on the simulated breaking conditions. Given an estimate of the elevated water level across the reef caused by storm surge and wave setup, depth limitations and fractional decay are estimated to define wave conditions at the toe of the proposed revetment. A rubble-mound revetment design stable in these conditions, armored by coral limestone quarried from the reef flat, is then formulated and corresponding material quantities estimated.

  3. a r r i o r BUILDING# NAME LOCATION BUILDING# NAME LOCATION OTHER BUILDINGS LOCATION SORORITIES LOCATION

    E-Print Network [OSTI]

    Carver, Jeffrey C.

    Admissions Parking Palmer Lake B l a c k W a r r i o r R i v e r BUILDING# NAME LOCATION BUILDING# NAME LOCATION OTHER BUILDINGS LOCATION SORORITIES LOCATION 7046 70127012 1155 10331033 1150 1039 1038

  4. Southern California Channel Islands Bibliography, through 1992

    E-Print Network [OSTI]

    Channel Islands National Marine Sanctuary

    1992-01-01T23:59:59.000Z

    pollution San Nicolas Island Atmospheric Sciences/Meteorology/Nuclear Science/Radioactivity/Atmospheric Sciences/Radioactivity/Radioactive Wastes/pollution/

  5. Islands and Our Renewable Energy Future (Presentation)

    SciTech Connect (OSTI)

    Baring-Gould, I.; Gevorgian, V.; Kelley, K.; Conrad, M.

    2012-05-01T23:59:59.000Z

    Only US Laboratory Dedicated Solely to Energy Efficiency and Renewable Energy. High Contribution Renewables in Islanded Power Systems.

  6. Transport, Aharonov-Bohm, and Topological Effects in Graphene Molecular Junctions and Graphene Nanorings

    E-Print Network [OSTI]

    Yannouleas, Constantine; Landman, Uzi

    2015-01-01T23:59:59.000Z

    The unique ultra-relativistic, massless, nature of electron states in two-dimensional extended graphene sheets, brought about by the honeycomb lattice arrangement of carbon atoms in two-dimensions, provides ingress to explorations of fundamental physical phenomena in graphene nanostructures. Here we explore the emergence of new behavior of electrons in atomically precise segmented graphene nanoribbons (GNRs) and graphene rings with the use of tight-binding calculations, non-equilibrium Green's function transport theory, and a newly developed Dirac continuum model that absorbs the valence-to-conductance energy gaps as position-dependent masses, including topological-in-origin mass-barriers at the contacts between segments. Through transport investigations in variable-width segmented GNRs with armchair, zigzag, and mixed edge terminations we uncover development of new Fabry-Perot-like interference patterns in segmented GNRs, a crossover from the ultra-relativistic massless regime, characteristic of extended gra...

  7. Evidence Against Klein Paradox in Graphene

    E-Print Network [OSTI]

    Daniela Dragoman

    2007-01-13T23:59:59.000Z

    It is demonstrated that both transmission and reflection coefficients associated to the Klein paradox at a step barrier are positive and less than unity, so that the particle-antiparticle pair creation mechanism commonly linked to this phenomenon is not necessary. Because graphene is a solid-state testing ground for quantum electrodynamics phenomena involving massless Dirac fermions we suggest that the transport characteristic through a p-n graphene junction can decide between the results obtained in this paper and the common Klein paradox theory, which imply negative transmission and higher-than-unity reflection coefficients. Recent experimental evidence supports our findings.

  8. Unconventional Integer Quantum Hall effect in graphene

    E-Print Network [OSTI]

    V. P. Gusynin; S. G. Sharapov

    2005-08-16T23:59:59.000Z

    Monolayer graphite films, or graphene, have quasiparticle excitations that can be described by 2+1 dimensional Dirac theory. We demonstrate that this produces an unconventional form of the quantized Hall conductivity $\\sigma_{xy} = - (2 e^2/h)(2n+1)$ with $n=0,1,...$, that notably distinguishes graphene from other materials where the integer quantum Hall effect was observed. This unconventional quantization is caused by the quantum anomaly of the $n=0$ Landau level and was discovered in recent experiments on ultrathin graphite films.

  9. Nonlocal Electromagnetic Response of Graphene Nanostructures

    E-Print Network [OSTI]

    Fallahi, Arya; Tamagnone, Michele; Perruisseau-Carrier, Julien

    2014-01-01T23:59:59.000Z

    Nonlocal electromagnetic effects of graphene arise from its naturally dispersive dielectric response. We present semi-analytical solutions of nonlocal Maxwell's equations for graphene nano-ribbons array with features around 100 nm, where we found prominent departures from its local response. Interestingly, the nonlocal corrections are stronger for light polarization parallel to the ribbons, which manifests as additional broadening of the Drude peak. For the perpendicular polarization case, nonlocal effects lead to blue-shifts of the plasmon peaks. These manifestations provide a physical measure of nonlocal effects, and we quantify their dependence on ribbon width, doping and wavelength.

  10. Bilayer graphene quantum dot defined by topgates

    SciTech Connect (OSTI)

    Müller, André; Kaestner, Bernd; Hohls, Frank; Weimann, Thomas; Pierz, Klaus; Schumacher, Hans W., E-mail: hans.w.schumacher@ptb.de [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany)

    2014-06-21T23:59:59.000Z

    We investigate the application of nanoscale topgates on exfoliated bilayer graphene to define quantum dot devices. At temperatures below 500 mK, the conductance underneath the grounded gates is suppressed, which we attribute to nearest neighbour hopping and strain-induced piezoelectric fields. The gate-layout can thus be used to define resistive regions by tuning into the corresponding temperature range. We use this method to define a quantum dot structure in bilayer graphene showing Coulomb blockade oscillations consistent with the gate layout.

  11. Photoluminescence study in diaminobenzene functionalized graphene oxide

    SciTech Connect (OSTI)

    Gupta, Abhisek, E-mail: guptaabhisek017@gmail.com, E-mail: cnssks@iacs.res.in; Saha, Shyamal K., E-mail: guptaabhisek017@gmail.com, E-mail: cnssks@iacs.res.in [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2014-10-15T23:59:59.000Z

    Being an excellent electronic material graphene is a very poor candidate for optoelectronic applications. One of the major strategies to develop the optical property in GO is the functionalization of graphene oxide (GO). In the present work GO sheets are functionalized by o-phenylenediamine to achieve diaminobenzene functionalized GO composite (DAB-GO). Formation of DAB-GO composite is further characterized by FTIR, UV, Raman studies. Excellent photoluminescence is observed in DAB-GO composite via passivation of the surface reactive sites by ring-opening amination of epoxides of GO.

  12. Mass Wasting in the Western Galapagos Islands

    E-Print Network [OSTI]

    Hall, Hillary

    2012-10-19T23:59:59.000Z

    the Hawaiian Islands, the western Galapagos Islands appear to be characterized by small slump sheets existing along the steep shallow submarine flanks of the island and by debris flows that are flanked by rift zones and extend off the platform. This study...

  13. Close Encounters Treasure Island: Sequencing Moorea

    E-Print Network [OSTI]

    Wildermuth, Mary C

    Close Encounters Also... Treasure Island: Sequencing Moorea Devon Zagory on Food Safety College Features 12 CLOSE ENCOUNTERS by Claire Cain Miller Passing earth science to the next generation 20 TREASURE ISLAND by Erika Check Barcoding CNR's island research station Departments 2 L

  14. Graphene Signal Amplification for Sensitive and Real-Time Fluorescence Anisotropy Detection of Small Molecules

    E-Print Network [OSTI]

    Tan, Weihong

    Graphene Signal Amplification for Sensitive and Real-Time Fluorescence Anisotropy Detection graphene oxide (GO) as the signal amplifier. Because of the extraordinarily larger volume of GO

  15. E-Print Network 3.0 - atomic layer graphene Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    graphene Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic layer graphene Page: << < 1 2 3 4 5 > >> 1 Graphite Handout Graphite is a...

  16. Geology and geochemistry of the Geyser Bight Geothermal Area, Umnak Island, Aleutian Islands, Alaska

    SciTech Connect (OSTI)

    Nye, C.J. (Alaska Univ., Fairbanks, AK (USA). Geophysical Inst. Alaska Dept. of Natural Resources, Fairbanks, AK (USA). Div. of Geological and Geophysical Surveys); Motyka, R.J. (Alaska Dept. of Natural Resources, Juneau, AK (USA). Div. of Geological and Geophysical Surveys); Turner, D.L. (Alaska Univ., Fairbanks, AK (USA). Geophysical Inst.); Liss, S.A. (Alaska Dept. of Natural Resources, Fairba

    1990-10-01T23:59:59.000Z

    The Geyser Bight geothermal area is located on Umnak Island in the central Aleutian Islands. It contains one of the hottest and most extensive areas of thermal springs and fumaroles in Alaska, and is only documented site in Alaska with geysers. The zone of hot springs and fumaroles lies at the head of Geyser Creek, 5 km up a broad, flat, alluvial valley from Geyser Bight. At present central Umnak is remote and undeveloped. This report describes results of a combined program of geologic mapping, K-Ar dating, detailed description of hot springs, petrology and geochemistry of volcanic and plutonic rock units, and chemistry of geothermal fluids. Our mapping documents the presence of plutonic rock much closer to the area of hotsprings and fumaroles than previously known, thus increasing the probability that plutonic rock may host the geothermal system. K-Ar dating of 23 samples provides a time framework for the eruptive history of volcanic rocks as well as a plutonic cooling age.

  17. National Park Service- San Miguel Island, California

    Broader source: Energy.gov [DOE]

    San Miguel Island is one of five islands that make up Channel Islands National Park on the coast of southern California. The islands comprise 249,353 acres (100,910 hectares) of land and ocean that teems with terrestrial and marine life. The National Park Service (NPS) protects the pristine resources at Channel Islands National Park by conserving, recycling, using alternative fuel vehicles, applying renewable energy, and using resources wisely. It also seeks to replace conventional fuels with renewable energy wherever possible. This applies especially to diesel fuel and petroleum, which must be shipped in from the mainland to generate electricity.

  18. Computer Lab Information Location

    E-Print Network [OSTI]

    Dangelmayr, Gerhard

    M340 Computer Lab Information · Location: The computer labs accessible to you are Weber 205 it is recommended that you save your files on a floppy when you are finished. · There is another directory, g:\\m340 to the saved files you have to add the directory to the Matlab path. To do this type addpath g:\\m340

  19. Aerial radiological and photographic survey of eleven atolls and two islands within the Northern Marshall Islands. Dates of surveys, July-November 1978

    SciTech Connect (OSTI)

    Not Available

    1981-06-01T23:59:59.000Z

    An aerial radiological survey was conducted over eleven atolls and two islands within the northern Marshall Islands between September and November 1978. This survey was part of a comprehensive radiological survey, which included extensive terrestrial and marine sampling, to determine possible residual contamination which might remain as a result of the United States nuclear testing program conducted at Bikini Enewetak Atolls between 1946 and 1958. A similar survey was conducted at Enewetak Atoll in 1972. The present survey covered those atolls known to have received direct fallout from the Bravo event, conducted in March 1954 at Bikini Atoll. These included Bikini, Rongelap, Rongerik, Ailinginae, Bikar, Taka, and Utirik Atolls. In addition, several atolls and islands which might have been at the fringes of the Bravo fallout were also surveyed, including Likiep and Ailuk Atolls, Jemo and Mejit Islands, and Wotho Atoll. Ujelang Atoll, which lies approximately 200 km southwest of Enewetak, was also surveyed. Island-averaged terrestrial exposure rates in the range of 30 to 50 ..mu..R/h were observed over parts of Bikini Atoll, including Bikini Island, and over the northern part of Rongelap Atoll. Levels over southern Rongelap and over Rongerik Atoll ranged from 4 to 7 ..mu..R/h. Levels were somewhat lower at Ailinginae Atoll (approximately 2 ..mu..R/h) and at Utirik Atoll (approximately 0.7 ..mu..R/h). The variations observed were consistent with what might be expected from the fallout pattern of the Bravo event. Levels at Ailuk, Likiep, Wotho and Ujelang Atolls and at Mejit and Jemo Islands were consistent with /sup 137/Cs activity, due to worldwide fallout, observed within the United States and at other locations in the central Pacific. These four atolls and the two islands, therefore, do not appear to have recieved any significant direct contamination from the Bravo event or the other tests conducted at Bikini and Enewetak Atolls.

  20. Magnetic island evolution in hot ion plasmas

    SciTech Connect (OSTI)

    Ishizawa, A.; Nakajima, N. [National Institute for Fusion Science, Toki 509-5292 (Japan); Waelbroeck, F. L.; Fitzpatrick, R.; Horton, W. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

    2012-07-15T23:59:59.000Z

    Effects of finite ion temperature on magnetic island evolution are studied by means of numerical simulations of a reduced set of two-fluid equations which include ion as well as electron diamagnetism in slab geometry. The polarization current is found to be almost an order of magnitude larger in hot than in cold ion plasmas, due to the strong shear of ion velocity around the separatrix of the magnetic islands. As a function of the island width, the propagation speed decreases from the electron drift velocity (for islands thinner than the Larmor radius) to values close to the guiding-center velocity (for islands of order 10 times the Larmor radius). In the latter regime, the polarization current is destabilizing (i.e., it drives magnetic island growth). This is in contrast to cold ion plasmas, where the polarization current is generally found to have a healing effect on freely propagating magnetic island.

  1. Four-dimensional graphene and chiral fermions

    E-Print Network [OSTI]

    Michael Creutz

    2008-03-25T23:59:59.000Z

    Motivated by the description of the graphene electronic structure in terms of the relativistic Dirac equation, a generalization to four dimensions yields a strictly local fermion action describing two species and possessing an exact chiral symmetry. This is the minimum number of species required by the well known ``no-go'' theorems.

  2. Graphene nanoribbon FETs: Technology exploration and CAD

    E-Print Network [OSTI]

    Mohanram, Kartik

    specified otherwise). Unlike traditional MOSFETs, SBFETs use metal or metal silicide contacts at the source carbon nanotubes (CNTs) [6]. Although two-dimensional graphene is a zero band-gap semi- metal, a band operation. Unlike CNTs, which are mixtures of metallic and semiconducting materials, recent samples

  3. Transport studies on CVD-grown graphene

    E-Print Network [OSTI]

    Huntley, Miriam Hanna

    2009-01-01T23:59:59.000Z

    In this thesis, we report transport studies performed on CVD-grown graphene. We perform resistivity and hall measurements on a large-area sample at 4' K. We measure the carrier mobility of the sample and find it to be on ...

  4. Insight into hydrogenation of graphene: Effect of hydrogen plasma chemistry

    SciTech Connect (OSTI)

    Felten, A.; Nittler, L.; Pireaux, J.-J. [Research Center in Physics of Matter and Radiation (PMR), University of Namur, Namur (Belgium); McManus, D. [School of Physics and Astronomy, University of Manchester, Manchester (United Kingdom); Rice, C.; Casiraghi, C. [School of Chemistry and Photon Science Institute, University of Manchester, Manchester (United Kingdom)

    2014-11-03T23:59:59.000Z

    Plasma hydrogenation of graphene has been proposed as a tool to modify the properties of graphene. However, hydrogen plasma is a complex system and controlled hydrogenation of graphene suffers from a lack of understanding of the plasma chemistry. Here, we correlate the modifications induced on monolayer graphene studied by Raman spectroscopy with the hydrogen ions energy distributions obtained by mass spectrometry. We measure the energy distribution of H{sup +}, H{sub 2}{sup +}, and H{sub 3}{sup +} ions for different plasma conditions showing that their energy strongly depends on the sample position, pressure, and plasma power and can reach values as high as 45?eV. Based on these measurements, we speculate that under specific plasma parameters, protons should possess enough energy to penetrate the graphene sheet. Therefore, a graphene membrane could become, under certain conditions, transparent to both protons and electrons.

  5. How effective is graphene nanopore geometry on DNA sequencing?

    E-Print Network [OSTI]

    Satarifard, Vahid; Ejtehadi, Mohammad Reza

    2015-01-01T23:59:59.000Z

    In this paper we investigate the effects of graphene nanopore geometry on homopolymer ssDNA pulling process through nanopore using steered molecular dynamic (SMD) simulations. Different graphene nanopores are examined including axially symmetric and asymmetric monolayer graphene nanopores as well as five layer graphene polyhedral crystals (GPC). The pulling force profile, moving fashion of ssDNA, work done in irreversible DNA pulling and orientations of DNA bases near the nanopore are assessed. Simulation results demonstrate the strong effect of the pore shape as well as geometrical symmetry on free energy barrier, orientations and dynamic of DNA translocation through graphene nanopore. Our study proposes that the symmetric circular geometry of monolayer graphene nanopore with high pulling velocity can be used for DNA sequencing.

  6. Enhancement in performance of polycarbazole-graphene nanocomposite Schottky diode

    SciTech Connect (OSTI)

    Pandey, Rajiv K.; Singh, Arun Kumar; Prakash, Rajiv, E-mail: rprakash.mst@itbhu.ac.in [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi-221005 (India)] [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi-221005 (India)

    2013-12-15T23:59:59.000Z

    We report formation of polycarbazole (PCz)–graphene nanocomposite over indium tin oxide (ITO) coated glass substrate using electrochemical technique for fabrication of high performance Schottky diodes. The synthesized nanocomposite is characterized before fabrication of devices for confirmation of uniform distribution of graphene nanosheets in the polymer matrix. Pure PCz and PCz-graphene nanocomposites based Schottky diodes are fabricated of configuration Al/PCz/ITO and Al/PCz-graphene nanocomposite/ITO, respectively. The current density–voltage (J-V) characteristics and diode performance parameters (such as the ideality factor, barrier height, and reverse saturation current density) are compared under ambient condition. Al/PCz-graphene nanocomposite/ITO device exhibits better ideality factor in comparison to the device formed using pure PCz. It is also observed that the Al/PCz-graphene nanocomposite/ITO device shows large forward current density and low turn on voltage in comparison to Al/PCz/ITO device.

  7. Quantum Hall effect in graphene decorated with disordered multilayer patches

    SciTech Connect (OSTI)

    Nam, Youngwoo, E-mail: youngwoo.nam@chalmers.se [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of) [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Sun, Jie, E-mail: jie.sun@chalmers.se; Lindvall, Niclas; Kireev, Dmitry; Yurgens, August [Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden)] [Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Jae Yang, Seung; Rae Park, Chong [Department of Materials Science and Engineering, Seoul National University, Seoul 151-747 (Korea, Republic of)] [Department of Materials Science and Engineering, Seoul National University, Seoul 151-747 (Korea, Republic of); Woo Park, Yung [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)] [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2013-12-02T23:59:59.000Z

    Quantum Hall effect (QHE) is observed in graphene grown by chemical vapour deposition using platinum catalyst. The QHE is even seen in samples which are irregularly decorated with disordered multilayer graphene patches and have very low mobility (<500 cm{sup 2}V{sup ?1}s{sup ?1}). The effect does not seem to depend on electronic mobility and uniformity of the resulting material, which indicates the robustness of QHE in graphene.

  8. Effect of topology on the critical charge in graphene

    E-Print Network [OSTI]

    Baishali Chakraborty; Kumar S. Gupta; Siddhartha Sen

    2010-11-18T23:59:59.000Z

    We show that the critical charge for the Dirac excitations in gapless graphene depends on the spatial topology of the sample. In particular, for graphene cones, the effective value of the critical charge can tend towards zero for a suitable angle of the conical sample. We discuss the nature of the scattering phase shifts, quasi-bound state energies and local density of states for a gapless graphene cone and determine the dependence of these physical quantities on the sample topology.

  9. Graphene materials having randomly distributed two-dimensional structural defects

    DOE Patents [OSTI]

    2013-10-08T23:59:59.000Z

    Graphene-based storage materials for high-power battery applications are provided. The storage materials are composed of vertical stacks of graphene sheets and have reduced resistance for Li ion transport. This reduced resistance is achieved by incorporating a random distribution of structural defects into the stacked graphene sheets, whereby the structural defects facilitate the diffusion of Li ions into the interior of the storage materials.

  10. Graphene as a Prototype Crystalline Membrane

    E-Print Network [OSTI]

    Mikhail I. Katsnelson; Annalisa Fasolino

    2013-02-07T23:59:59.000Z

    The understanding of the structural and thermal properties of membranes, low-dimensional flexible systems in a space of higher dimension, is pursued in many fields from string theory to chemistry and biology. The case of a two-dimensional (2D) membrane in three dimensions is the relevant one for dealing with real materials. Traditionally, membranes are primarily discussed in the context of biological membranes and soft matter in general. The complexity of these systems hindered a realistic description of their interatomic structures based on a truly microscopic approach. Therefore, theories of membranes were developed mostly within phenomenological models. From the point of view of statistical mechanics, membranes at finite temperature are systems governed by interacting long-range fluctuations. Graphene, the first truly two-dimensional system consisting of just one layer of carbon atoms, provides a model system for the development of a microscopic description of membranes. In this Account, we review key results in the microscopic theory of structural and thermal properties of graphene and compare them with the predictions of phenomenological theories. The two approaches are in good agreement for the various scaling properties of correlation functions of atomic displacements. However, some other properties, such as the temperature dependence of the bending rigidity, cannot be understood based on phenomenological approaches. We also consider graphene at very high temperature and compare the results with existing models for two-dimensional melting. The melting of graphene presents a different scenario, and we describe that process as the decomposition of the graphene layer into entangled carbon chains.

  11. Electric current locator

    DOE Patents [OSTI]

    King, Paul E. (Corvallis, OR); Woodside, Charles Rigel (Corvallis, OR)

    2012-02-07T23:59:59.000Z

    The disclosure herein provides an apparatus for location of a quantity of current vectors in an electrical device, where the current vector has a known direction and a known relative magnitude to an input current supplied to the electrical device. Mathematical constants used in Biot-Savart superposition equations are determined for the electrical device, the orientation of the apparatus, and relative magnitude of the current vector and the input current, and the apparatus utilizes magnetic field sensors oriented to a sensing plane to provide current vector location based on the solution of the Biot-Savart superposition equations. Description of required orientations between the apparatus and the electrical device are disclosed and various methods of determining the mathematical constants are presented.

  12. Graphene surface emitting terahertz laser: Diffusion pumping concept

    SciTech Connect (OSTI)

    Davoyan, Arthur R., E-mail: davoyan@seas.upenn.edu [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019, Russia and Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Morozov, Mikhail Yu.; Popov, Vyacheslav V. [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019 (Russian Federation)] [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019 (Russian Federation); Satou, Akira; Otsuji, Taiichi [Research Institute of Electrical Communication (RIEC), Tohoku University, Sendai, Miyagi 980-8577 (Japan)] [Research Institute of Electrical Communication (RIEC), Tohoku University, Sendai, Miyagi 980-8577 (Japan)

    2013-12-16T23:59:59.000Z

    We suggest a concept of a tunable graphene-based terahertz (THz) surface emitting laser with diffusion pumping. We employ significant difference in the electronic energy gap of graphene and a typical wide-gap semiconductor, and demonstrate that carriers generated in the semiconductor can be efficiently captured by graphene resulting in population inversion and corresponding?THz lasing from graphene. We develop design principles for such a laser and estimate its performance. We predict up to 50?W/cm{sup 2} terahertz power output for 100?kW/cm{sup 2} pump power at frequency around 10?THz at room temperature.

  13. Graphene and its Hybrid Nanostructures for Nanoelectronics and Energy Applications.

    E-Print Network [OSTI]

    LIN, JIAN

    2011-01-01T23:59:59.000Z

    ??This dissertation focuses on investigating the synthesis of graphene and its hybrid nanostructures by chemical vapor deposition (CVD) process, as well as their applications in… (more)

  14. Gate-controlled ultraviolet photo-etching of graphene edges

    SciTech Connect (OSTI)

    Mitoma, Nobuhiko; Nouchi, Ryo [Nanoscience and Nanotechnology Research Center, Osaka Prefecture University, Sakai, Osaka 599-8570 (Japan)] [Nanoscience and Nanotechnology Research Center, Osaka Prefecture University, Sakai, Osaka 599-8570 (Japan)

    2013-11-11T23:59:59.000Z

    The chemical reactivity of graphene under ultraviolet (UV) light irradiation is investigated under positive and negative gate electric fields. Graphene edges are selectively etched when negative gate voltages are applied while the reactivity is significantly suppressed for positive gate voltages. Oxygen adsorption onto graphene is significantly affected by the Fermi level of the final state achieved during previous electrical measurements. UV irradiation after negative-to-positive gate sweeps causes predominant oxygen desorption while UV irradiation after gate sweeps in the opposite direction causes etching of graphene edges.

  15. Symmetry Breaking in Graphene Gregory S. Boebinger, National...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Symmetry Breaking in Graphene Gregory S. Boebinger, National High Magnetic Field Laboratory DMR-Award 0654118 DC Field Facility While the laws of physics are often symmetric,...

  16. Magneto-plasmons in Quasi-neutral Epitaxial Graphene Nanoribbons

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Graphene plasmons, the collective oscillations of Dirac fermions, are difficult to probe near charge neutrality where new physics are expected to emerge. Using the NHMFL...

  17. Graphene and its derivatives : fabrication and Raman spectroscopy study.

    E-Print Network [OSTI]

    Cong, Chunxiao.

    2012-01-01T23:59:59.000Z

    ??This thesis presents results on fabrication and Raman spectroscopy studies of graphene and its derivates. The works can be divided into two parts as follows.… (more)

  18. Tunable fractional quantum Hall phases in bilayer graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Coulomb interactions drive the existence of a correlated many-body state. Bilayer graphene represents a particularly interesting material in which to study the fractional...

  19. Tunable deep-subwavelength superscattering using graphene monolayers

    E-Print Network [OSTI]

    Li, R J; Lin, S S; Liu, X; Chen, H S

    2015-01-01T23:59:59.000Z

    In this Letter, we theoretically propose for the first time that graphene monolayers can be used for superscatterer designs. We show that the scattering cross section of the bare deep-subwavelength dielectric cylinder is markedly enhanced by six orders of magnitude due to the excitation of the first-order resonance of graphene plamons. By utilizing the tunability of the plasmonic resonance through tuning graphene's chemical potential, the graphene superscatterer works in a wide range of frequencies from several terahertz to tens of terahertz.

  20. Characterization of the cleaning process on a transferred graphene

    SciTech Connect (OSTI)

    Huang, Li-Wei [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan (China); Chang, Cheng-Kai [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan and Institute of Polymer Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Chien, Fan-Ching [Department of Optics and Photonics, National Central University, Chung-Li 320, Taiwan (China); Chen, Kuei-Hsien [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Chen, Peilin [Research Center of Applied Science, Academia Sinica, Taipei 115, Taiwan (China); Chen, Fu-Rong [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); Chang, Chia-Seng, E-mail: jasonc@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 115, Taiwan and Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan (China)

    2014-09-01T23:59:59.000Z

    Intrinsic graphene possesses many outstanding physical and chemical properties, but their full explorations are often hindered by the effects of substrate and/or contamination. The authors employ the ultrahigh vacuum transmission electron microscopy equipped with a residual gas analyzer to in-situ characterize an effective decontamination process on a suspended graphene. Raman spectroscopic spectra further verify the cleanness of the resultant graphene membrane. The authors also present two contrasting growth morphologies of copper nanoparticles obtained on both clean and unclean graphene surfaces and show that the intrinsic growth dynamics can only manifest on the surface without contaminations.

  1. Experimental verification of electro-refractive phase modulation in graphene

    E-Print Network [OSTI]

    Mohsin, Muhammad; Schall, Daniel; Otto, Martin; Matheisen, Christopher; Giesecke, Anna Lena; Sagade, Abhay A; Kurz, Heinrich

    2015-01-01T23:59:59.000Z

    Graphene has been considered as a promising material for opto-electronic devices, because of its tunable and wideband optical properties. In this work, we demonstrate electro-refractive phase modulation in graphene at wavelengths from 1530 to 1570 nm. By integrating a gated graphene layer in a silicon-waveguide based Mach-Zehnder interferometer, the key parameters of a phase modulator like change in effective refractive index, insertion loss and absorption change are extracted. These experimentally obtained values are well reproduced by simulations and design guidelines are provided to make graphene devices competitive to contemporary silicon based phase modulators for on-chip applications.

  2. Graphene-coated coupling coil for AC resistance reduction

    DOE Patents [OSTI]

    Miller, John M

    2014-03-04T23:59:59.000Z

    At least one graphene layer is formed to laterally surround a tube so that the basal plane of each graphene layer is tangential to the local surface of the tube on which the graphene layer is formed. An electrically conductive path is provided around the tube for providing high conductivity electrical path provided by the basal plane of each graphene layer. The high conductivity path can be employed for high frequency applications such as coupling coils for wireless power transmission to overcome skin depth effects and proximity effects prevalent in high frequency alternating current paths.

  3. Buckling and Topological Defects in Graphene and Carbon Nanotubes

    E-Print Network [OSTI]

    Chen, Shuo

    2012-01-01T23:59:59.000Z

    4 Plasticity in Carbon Nanotubes 4.1Ultimate strength of carbon nanotubes: a theoretical study”.formation energy in carbon nanotubes and graphene”. In:

  4. Electrical and thermal conductivity of low temperature CVD graphene...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and thermal conductivity of low temperature CVD graphene: the effect of disorder This article has been downloaded from IOPscience. Please scroll down to see the full text article....

  5. Graphene and its Hybrid Nanostructures for Nanoelectronics and Energy Applications

    E-Print Network [OSTI]

    LIN, JIAN

    2011-01-01T23:59:59.000Z

    al. Graphene-Based Supercapacitor with an Ultrahigh Energynanostructures films for supercapacitor. submitted, 2011. p.B. E. Transition from Supercapacitor to Battery Behavior in

  6. Graphene and Black Holes: novel materials to reach the unreachable

    E-Print Network [OSTI]

    Iorio, Alfredo

    2014-01-01T23:59:59.000Z

    The case for a dedicated laboratory, to test hep-th models on analogue systems, is briefly made. The focus is on graphene.

  7. Tunable subwavelength strong absorption by graphene wrapped dielectric particles

    E-Print Network [OSTI]

    Yang, Bing; Yang, Yue; Zhang, Xiangdong

    2015-01-01T23:59:59.000Z

    The optical absorption properties of graphene wrapped dielectric particles have been investigated by using Mie scattering theory and exact multi-scattering method. It is shown that subwavelength strong absorption in infrared spectra can take place in such systems due to the excitation of plasmon resonance in graphene. The absorption characteristics and efficiency are tunable by varying Fermi level and damping constant of graphene, or by changing size and dielectric constant of small particles. For a cluster of these particles, the absorption characteristics are also affected by the separation distance between them. These extreme light resonances and absorptions in graphene wrapped nanostructures have great potential for opto-electronic devices.

  8. Quantum transport via evanescent waves in undoped graphene

    E-Print Network [OSTI]

    M. I. Katsnelson

    2011-01-13T23:59:59.000Z

    Charge carriers in graphene are chiral quasiparticles ("massless Dirac fermions"). Graphene provides therefore an amazing opportunity to study subtle quantum relativistic effects in condensed matter experiment. Here I review a theory of one of these unusual features of graphene, a "pseudodiffusive" transport in the limit of zero charge carrier concentration, which is related to existence of zero-modes of the Dirac operator and to the Zitterbewegung of unltrarelativistic particles. A conformal mapping technique is a powerful mathematical tool to study these phenomena, as demonstrated here, using the Aharonov-Bohm effect in graphene rings with Corbino geometry as an example.

  9. Functionalized Graphene Oxide as a Nanocarrier in a Multienzyme...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in a Multienzyme Labeling Amplification Strategy for Ultrasensitive Functionalized Graphene Oxide as a Nanocarrier in a Multienzyme Labeling Amplification Strategy for...

  10. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic...

  11. Graphene defect formation by extreme ultraviolet generated photoelectrons

    SciTech Connect (OSTI)

    Gao, A., E-mail: a.gao@utwente.nl; Lee, C. J.; Bijkerk, F. [FOM-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands and XUV Optics Group, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands)

    2014-08-07T23:59:59.000Z

    We have studied the effect of photoelectrons on defect formation in graphene during extreme ultraviolet (EUV) irradiation. Assuming the major role of these low energy electrons, we have mimicked the process by using low energy primary electrons. Graphene is irradiated by an electron beam with energy lower than 80?eV. After e-beam irradiation, it is found that the D peak, I(D), appears in the Raman spectrum, indicating defect formation in graphene. The evolution of I(D)/I(G) follows the amorphization trajectory with increasing irradiation dose, indicating that graphene goes through a transformation from microcrystalline to nanocrystalline and then further to amorphous carbon. Further, irradiation of graphene with increased water partial pressure does not significantly change the Raman spectra, which suggests that, in the extremely low energy range, e-beam induced chemical reactions between residual water and graphene are not the dominant mechanism driving defect formation in graphene. Single layer graphene, partially suspended over holes was irradiated with EUV radiation. By comparing with the Raman results from e-beam irradiation, it is concluded that the photoelectrons, especially those from the valence band, contribute to defect formation in graphene during irradiation.

  12. Gelatin/graphene systems for low cost energy storage

    SciTech Connect (OSTI)

    Landi, Giovanni [Faculty of Mathematics and Computer Science, FernUniversität Hagen, 58084 Hagen (Germany); Fedi, Filippo; Sorrentino, Andrea; Iannace, Salvatore [Institute for Composite and Biomedical Materials (IMCB-CNR), Piazzale Enrico Fermi 1, 80055 Portici (Italy); Neitzert, Heinz C. [Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (Italy)

    2014-05-15T23:59:59.000Z

    In this work, we introduce the possibility to use a low cost, biodegradable material for temporary energy storage devices. Here, we report the use of biologically derived organic electrodes composed of gelatin ad graphene. The graphene was obtained by mild sonication in a mixture of volatile solvents of natural graphite flakes and subsequent centrifugation. The presence of exfoliated graphene sheets was detected by atomic force microscopy (AFM) and Raman spectroscopy. The homogeneous dispersion in gelatin demonstrates a good compatibility between the gelatin molecules and the graphene particles. The electrical characterization of the resulting nanocomposites suggests the possible applications as materials for transient, low cost energy storage device.

  13. Adsorption of silver dimer on graphene - A DFT study

    SciTech Connect (OSTI)

    Kaur, Gagandeep, E-mail: gaganj1981@yahoo.com [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014, India and Chandigarh Engineering College, Landran, Mohali-140307, Punjab (India); Gupta, Shuchi [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014, India and University Institute of Engineering and Technology, Panjab University, Chandigarh -160014 (India); Rani, Pooja; Dharamvir, Keya [Department of Physics and Centre of Advanced Studies in Physics, Panjab University, Chandigarh-160014 (India)

    2014-04-24T23:59:59.000Z

    We performed a systematic density functional theory (DFT) study of the adsorption of silver dimer (Ag{sub 2}) on graphene using SIESTA (Spanish Initiative for Electronic Simulations with Thousands of Atoms) package, in the generalized gradient approximation (GGA). The adsorption energy, geometry, and charge transfer of Ag2-graphene system are calculated. The minimum energy configuration for a silver dimer is parallel to the graphene sheet with its two atoms directly above the centre of carbon-carbon bond. The negligible charge transfer between the dimer and the surface is also indicative of a weak bond. The methodology demonstrated in this paper may be applied to larger silver clusters on graphene sheet.

  14. Increase of the grating coupler bandwidth with a graphene overlay

    SciTech Connect (OSTI)

    Cheng, Zhenzhou; Li, Zhen; Xu, Ke; Tsang, Hon Ki, E-mail: hktsang@ee.cuhk.edu.hk [Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin (Hong Kong)

    2014-03-17T23:59:59.000Z

    We present theoretical and experimental results that demonstrate an increase in the grating bandwidth by placing a graphene on the chip. A focusing subwavelength grating with coupling efficiency of ?4.3?dB and 1?dB bandwidth of ?60?nm was demonstrated. After a graphene sheet was transferred onto the chip, the maximum 1?dB bandwidth was increased to ?72?nm. Experimental results are consistent with the calculated graphene induced waveguide refractive index and dispersion changes, and the bandwidth improvement may be attributed to the reduction of grating dispersion. This study may be of interest for graphene-on-silicon photonic integrated circuit applications.

  15. Exploring the interaction between lithium ion and defective graphene...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Exploring the interaction between lithium ion and defective graphene surface using dispersion corrected DFT studies. Exploring the interaction between lithium ion and defective...

  16. Graphene shield enhanced photocathodes and methods for making the same

    SciTech Connect (OSTI)

    Moody, Nathan Andrew

    2014-09-02T23:59:59.000Z

    Disclosed are graphene shield enhanced photocathodes, such as high QE photocathodes. In certain embodiments, a monolayer graphene shield membrane ruggedizes a high quantum efficiency photoemission electron source by protecting a photosensitive film of the photocathode, extending operational lifetime and simplifying its integration in practical electron sources. In certain embodiments of the disclosed graphene shield enhanced photocathodes, the graphene serves as a transparent shield that does not inhibit photon or electron transmission but isolates the photosensitive film of the photocathode from reactive gas species, preventing contamination and yielding longer lifetime.

  17. Graphene decorated with PtAu alloy nanoparticles: facile synthesis...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    nanoparticles: facile synthesis and promising application for formic acid oxidation. Graphene decorated with PtAu alloy nanoparticles: facile synthesis and promising application...

  18. Reducing disorder in graphene nanoribbons by chemical edge modification

    SciTech Connect (OSTI)

    Dauber, J.; Terrés, B.; Volk, C.; Stampfer, C. [JARA-FIT and II. Institute of Physics, RWTH Aachen University, 52074 Aachen (Germany); Peter Grünberg Institute (PGI-8/9), Forschungszentrum Jülich, 52425 Jülich (Germany); Trellenkamp, S. [Peter Grünberg Institute (PGI-8/9), Forschungszentrum Jülich, 52425 Jülich (Germany)

    2014-02-24T23:59:59.000Z

    We present electronic transport measurements on etched graphene nanoribbons on silicon dioxide before and after a short hydrofluoric acid (HF) treatment. We report on changes in the transport properties, in particular, in terms of a decreasing transport gap and a reduced doping level after HF dipping. Interestingly, the effective energy gap is nearly unaffected by the HF treatment. Additional measurements on a graphene nanoribbon with lateral graphene gates support strong indications that the HF significantly modifies the edges of the investigated nanoribbons leading to a significantly reduced disorder potential in these graphene nanostructures.

  19. Graphene-based Materials for Biosensing and Bioimaging

    SciTech Connect (OSTI)

    Du, Dan; Yang, Yuqi; Lin, Yuehe

    2012-12-01T23:59:59.000Z

    Graphene, a free-standing two-dimensional crystal with one-atom thickness, exhibits distinct properties that are highly attractive for biosensing and bioimaging, such as a high electrical conductivity, a large planar area, and an excellent ability to quench fluorescence. This article selectively reviews recent advances in the field of graphene-based materials for biosensing and bioimaging. In particular, graphene-based enzyme biosensors, DNA biosensors, and immunosensors are summarized in detail. Graphene-based biotechnology for cell imaging is also described. Future perspectives and possible challenges in this rapidly developing area are also discussed.

  20. Graphene and Black Holes: novel materials to reach the unreachable

    E-Print Network [OSTI]

    Alfredo Iorio

    2014-12-15T23:59:59.000Z

    The case for a dedicated laboratory, to test hep-th models on analogue systems, is briefly made. The focus is on graphene.