National Library of Energy BETA

Sample records for locate graphene islands

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

    E-Print Network [OSTI]

    Brune, Harald

    generation electronic devices [2]. Freestanding graphene is a zero-gap semiconductor. Because most electronicHighly Anisotropic Dirac Cones in Epitaxial Graphene Modulated by an Island Superlattice S. Rusponi asymmetry in epitaxial graphene by using metal cluster superlattices self-assembled onto the moire´ pattern

  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. High Island Densities and Long Range Repulsive Interactions: Fe on Epitaxial Graphene

    SciTech Connect (OSTI)

    Binz, Steven M.; Hupalo, Myron; Liu, Xiaojie; Wang, Cai-Zhuang; Lu, Wen-Cai; Thiel, Kai-Ming; Conrad, E.H.; Tringides, Michael C.

    2012-07-13

    The understanding of metal nucleation on graphene is essential for promising future applications, especially of magnetic metals which can be used in spintronics or computer storage media. A common method to study the grown morphology is to measure the nucleated island density n as a function of growth parameters. Surprisingly, the growth of Fe on graphene is found to be unusual because it does not follow classical nucleation: n is unexpectedtly high, it increases continuously with the deposited amount ? and shows no temperature dependence. These unusual results indicate the presence of long range repulsive interactions. Kinetic Monte Carlo simulations and density functional theory calculations support this conclusion. In addition to answering an outstanding question in epitaxial growth, i.e., to find systems where long range interactions are present, the high density of magnetic islands, tunable with ?, is of interest for nanomagnetism applications.

  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

    2014-01-01

    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. Tuning nucleation density of metal island with charge doping of graphene substrate

    SciTech Connect (OSTI)

    Ming, Wenmei; Liu, Feng

    2014-08-18

    We have demonstrated that the island nucleation in the initial stage of epitaxial thin film growth can be tuned by substrate surface charge doping. This charge effect was investigated using spin density functional theory calculation in Fe-deposition on graphene substrate as an example. It was found that hole-doping can noticeably increase both Fe-adatom diffusion barrier and Fe inter-adatom repulsion energy occurring at intermediate separation, whereas electron-doping can decrease Fe-adatom diffusion barrier but only slightly modify inter-adatom repulsion energy. Further kinetic Monte Carlo simulation showed that the nucleation island number density can be increased up to six times larger under hole-doping and can be decreased down to ten times smaller under electron doping than that without doping. Our findings indicate a route to tailor the growth morphology of magnetic metal nanostructure for spintronics and plasmonic applications via surface charge doping.

  6. artha's Vineyard Shellfish Group is a public nonprofit located on Martha's Vineyard Island

    E-Print Network [OSTI]

    New Hampshire, University of

    M artha's Vineyard Shellfish Group is a public nonprofit located on Martha's Vineyard Island in Massachusetts. History The Group was founded over thirty years ago in order to help the six towns on the island per year of extreme heat (over 90° Fahrenheit) in Massachusetts.1 Martha's Vineyard Shellfish Group

  7. Error Analysis of Bathymetric Data Derived from IKONOS Imagery Location: Tutuila Island, American Samoa

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    1 Error Analysis of Bathymetric Data Derived from IKONOS Imagery Location: Tutuila Island, American) / NOAA Fisheries' Coral Reef Ecosystem Division (CRED) Analysis Overview Bathymetric data were derived analyzed to extend the spatial coverage of the final derived bathymetry product. The imagery was provided

  8. 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

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

    SciTech Connect (OSTI)

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

    2005-11-08

    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.

  10. ISLANDER

    Energy Science and Technology Software Center (OSTI)

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

  11. Collapsed graphene

    E-Print Network [OSTI]

    0.1% strain Collapsed graphene Suspended graphene 1. First, 2 gold supports layer sandwiched in between. 2. Graphene is laid across the surface, collapsing and straining the graphene and compleHng the device. Approach I: Crea

  12. NAME: Kent Island Restoration at Bolinas Lagoon LOCATION: Bolinas/Stinson Beach/Marin County/California

    E-Print Network [OSTI]

    US Army Corps of Engineers

    DESCRIPTION: This project will restore 23 acres of tidal marsh/ecotone/coastal dune habitat on Kent Island in Bolinas Lagoon. Native dune habitat on the Pacific Coast has been affected by development and invasive plants. This project will remove invasive species and restore native vegetation, and de- anchor

  13. 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

  14. Thermal Conduction in Graphene and Graphene Multilayers

    E-Print Network [OSTI]

    Ghosh, Suchismita

    2009-01-01

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

  15. 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...

  16. Graphene aerogels

    DOE Patents [OSTI]

    Pauzauskie, Peter J; Worsley, Marcus A; Baumann, Theodore F; Satcher, Jr., Joe H; Biener, Juergen

    2015-03-31

    Graphene aerogels with high conductivity and surface areas including a method for making a graphene aerogel, including the following steps: (1) preparing a reaction mixture comprising a graphene oxide suspension and at least one catalyst; (2) curing the reaction mixture to produce a wet gel; (3) drying the wet gel to produce a dry gel; and (4) pyrolyzing the dry gel to produce a graphene aerogel. Applications include electrical energy storage including batteries and supercapacitors.

  17. Vertical graphene base transistor

    E-Print Network [OSTI]

    2012-01-01

    M. Baus, and H. Kurz, “A graphene ?eld-effect device,” IEEERooks, and P. Avouris, “Graphene nano- ribbon electronics,”High-frequency, scaled graphene transistors on diamond- like

  18. Noncommutative Graphene

    E-Print Network [OSTI]

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

    2012-07-24

    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.

  19. Arctic ice islands

    SciTech Connect (OSTI)

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

    1988-01-01

    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.

  20. Nanoscale friction properties of graphene and graphene oxide...

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

    Nanoscale friction properties of graphene and graphene oxide Title Nanoscale friction properties of graphene and graphene oxide Publication Type Journal Article Year of Publication...

  1. Raman Nanometrology of Graphene

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01

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

  2. 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)

    2014-02-21

    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.

  3. Molecular analysis of secretion genes located on the syr-syp genomic island of Pseudomonas syringae pv. syringae strain B301D 

    E-Print Network [OSTI]

    Kang, Hyojeung

    2005-02-17

    An RND (resistance-nodulation-cell division) transporter, called the PseC protein, was identified at the left border of the syr-syp genomic island of Pseudomonas syringae pv. syringae strain B301D. The PseC protein exhibited ...

  4. 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

  5. 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...

  6. Basaltic island sand provenance

    SciTech Connect (OSTI)

    Marsaglia, K.M. . Dept. of Geological Sciences)

    1992-01-01

    The Hawaiian Islands are an ideal location to study basaltic sand provenance in that they are a series of progressively older basaltic shield volcanoes with arid to humid microclimates. Sixty-two sand samples were collected from beaches on the islands of Hawaii, Maui, Oahu and Kauai and petrographically analyzed. The major sand components are calcareous bioclasts, volcanic lithic fragments, and monomineralic grains of dense minerals and plagioclase. Proportions of these components vary from island to island, with bioclastic end members being more prevalent on older islands exhibiting well-developed fringing reef systems and volcanic end members more prevalent on younger, volcanically active islands. Climatic variations across the island of Hawaii are reflected in the percentage of weathered detritus, which is greater on the wetter, northern side of the island. The groundmass of glassy, basaltic lithics is predominantly black tachylite, with lesser brown sideromelane; microlitic and lathwork textures are more common than holohyaline vitric textures. Other common basaltic volcanic lithic fragments are holocrystalline aggregates of silt-sized pyroxene or olivine, opaque minerals and plagioclase. Sands derived from alkalic lavas are texturally and compositionally indistinguishable from sands derived from tholeiitic lavas. Although Hawaiian basaltic sands overlap in composition with magmatic arc-derived sands in terms of their relative QFL, QmPK and LmLvLs percentages, they are dissimilar in that they lack felsic components and are more enriched in lathwork volcanic lithic fragments, holocrystalline volcanic lithic fragments, and dense minerals.

  7. 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

  8. 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

  9. 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

  10. Marine Bird Ecology & Conservation: The Farallon Islands

    E-Print Network [OSTI]

    Brown, Sally

    11/19/2014 1 Marine Bird Ecology & Conservation: The Farallon Islands Example Some Historical;11/19/2014 2 Charadriformes: gulls, terns Anseriformes: marine ducks, geese and swans Other birds Location of island Distant photo of island #12;11/19/2014 3 Western Gull The gull colony on the marine terrace

  11. Electronic and Spintronic Properties of Graphene

    E-Print Network [OSTI]

    Pi, Keyu

    2010-01-01

    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

  12. 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)

    2014-07-28

    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.

  13. The Electronic Structure of Single-Layer Graphene

    E-Print Network [OSTI]

    Siegel, David Alan

    2012-01-01

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

  14. Raman Nanometrology of Graphene

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01

    graphene is a promising material for the electronic applications beyond the conventional complementary metal-oxide semiconductor (graphene is considered for applications in the integrated circuits beyond the conventional silicon complementary metal- oxide semiconductor

  15. 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 ...

  16. Thermal Conduction in Graphene and Graphene Multilayers

    E-Print Network [OSTI]

    Ghosh, Suchismita

    2009-01-01

    1 1.2 Thermal transport atxv Introduction xii 1.1 Thermal conductivity and65 4.13 Thermal conductivity of graphene as a function of

  17. Electrical Transport in Carbon Nanotubes and Graphene

    E-Print Network [OSTI]

    Liu, Gang

    2010-01-01

    Device Fabrication Graphene preparation is the same as theevaporation. After graphene preparation on the substrate, we

  18. 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

  19. Nauru Island Effect Detection Data Set

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

    Long, Chuck

    2010-07-15

    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. 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

  1. Electrical Properties of Trilayer Graphene

    E-Print Network [OSTI]

    Lee, Yongjin

    2014-01-01

    Fabrication of graphene p-n-p junctions with contactless topFabrication of graphene p-n-p junctions with contactless topFabrication of graphene p-n-p junctions with contactless top

  2. 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...

  3. Hot carrier diffusion in graphene

    E-Print Network [OSTI]

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

    2010-11-01

    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...

  4. Ascension Island

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

    U.S. Air Force Space Command - Ascension Island Personnel from the Power Systems Engineering Department, in conjunction with the U.S. Air Force, U.S. Navy, and other partners,...

  5. Twist Solves Bilayer Graphene Mystery

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

    spectroscopy (ARPES) to bilayer graphene. Through direct band-structure measurements and calculations, they discovered that in the stacking of graphene monolayers,...

  6. Search for: graphene | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    graphene Find + Advanced Search Advanced Search All Fields: graphene Title: Full Text: Bibliographic Data: Creator Author: Name Name ORCID Search Authors Type: All Accepted...

  7. SciTech Connect: graphene

    Office of Scientific and Technical Information (OSTI)

    graphene Find + Advanced Search Term Search Semantic Search Advanced Search All Fields: graphene Semantic Semantic Term Title: Full Text: Bibliographic Data: Creator Author:...

  8. 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...

  9. Metals on graphene: correlation between adatom adsorption behavior and growth morphology

    SciTech Connect (OSTI)

    Liu, Xiaojie; Wang, Cai-Zhuang; Hupalo, Myron; Lu, Wencai; Tringides, Michael C.; Yao, Yongxin; Ho, Kai-Ming

    2012-05-19

    We present a systematic study of metal adatom adsorption on graphene by ab initio calculations. The calculations cover alkali metals, sp-simple metals, 3d and group 10 transition metals, noble metals, as well as rare earth metals. The correlation between the adatom adsorption properties and the growth morphology of the metals on graphene is also investigated. We show that the growth morphology is related to the ratio of the metal adsorption energy to its bulk cohesive energy (E(a)/E(c)) and the diffusion barrier (?E) of the metal adatom on graphene. Charge transfer, electric dipole and magnetic moments, and graphene lattice distortion induced by metal adsorption would also affect the growth morphologies of the metal islands. We also show that most of the metal nanostructures on graphene would be thermally stable against coarsening.

  10. 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)

    2014-09-01

    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.

  11. Electronic and Spintronic Properties of Graphene

    E-Print Network [OSTI]

    Pi, Keyu

    2010-01-01

    lifetime in graphene)……………47 4.3: Device preparation (ebeambetween TM and graphene. 3.2: Device preparation (ebeamspin relaxation in graphene? 4.3: Device preparation (ebeam

  12. Chemistry at the Dirac Point of Graphene

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01

    used today for the preparation of graphene oxide, rGO andengineering in graphene and preparation of electrochemicallypreparation, isolation, and characterization of graphene.

  13. Carbon Nanotube and Graphene Nanoelectromechanical Systems

    E-Print Network [OSTI]

    Aleman, Benjamin Jose

    2011-01-01

    conventional serial preparation of graphene TEM grids orMembranes The preparation of suspended graphene structuresreports on graphene TEM grid preparation[84]. Electron di?

  14. Electronic Transport in Few-layer Graphene

    E-Print Network [OSTI]

    Zhao, Zeng

    2013-01-01

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

  15. Electrical and Mechanical Properties of Graphene

    E-Print Network [OSTI]

    Bao, Wenzhong

    2011-01-01

    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 (

  16. Electrical Transport in Carbon Nanotubes and Graphene

    E-Print Network [OSTI]

    Liu, Gang

    2010-01-01

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

  17. Electrical and Thermoelectrical Transport Properties of Graphene

    E-Print Network [OSTI]

    Wang, Deqi

    2011-01-01

    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

  18. Transport Properties of Bilayer Graphene Nanoribbons

    E-Print Network [OSTI]

    Wang, Minsheng

    2013-01-01

    operation in single-layer graphene ferroelectric memory”.Mobility in Suspended Graphene. Solid State Commun. 2008,Transport in Suspended Graphene. Phys. Rev. Lett. 2008,

  19. Local Density of States in Graphene

    E-Print Network [OSTI]

    Yang, Ling

    2011-01-01

    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)

  20. Symmetry Breaking in Few Layer Graphene Films

    E-Print Network [OSTI]

    2008-01-01

    Biased bilayer graphene: semiconductor with a gap tunable bytemperature, graphene is a gapless semiconductor or a zero-semiconductor two dimensional electron gases), graphene ?lms

  1. Transport Properties of Bilayer Graphene Nanoribbons

    E-Print Network [OSTI]

    Wang, Minsheng

    2013-01-01

    Biased Bilayer Graphene: Semiconductor with a Gap Tunable byUltrasmooth Graphene Nanoribbon Semiconductors. Sciencedimensional semiconductors and single-layer graphene films (

  2. Graphene Growth on Low Carbon Solubility Metals

    E-Print Network [OSTI]

    Wofford, Joseph Monroe

    2012-01-01

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

  3. Energy Transition Initiative, Island Energy Snapshot - Jamaica; NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    2015-04-06

    This profile provides a snapshot of the energy landscape of Jamaica, an island nation located in the north Caribbean Sea.

  4. Raman Nanometrology of Graphene

    E-Print Network [OSTI]

    Calizo, Irene Gonzales

    2009-01-01

    2D) electron gas physics it reveals, graphene is a promising material for the electronic applications beyond the conventional complementary metal-oxide semiconductor (

  5. Controlling Graphene's Electronic Structure

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

    semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's electrical charge carriers (electrons and holes) move through a solid...

  6. Controlling Graphene's Electronic Structure

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

    was reopened by the excess of electron charge-carriers on the graphene's surface layer. Progressive potassium deposition further enhanced the n-type doping. These results...

  7. Tunable nonlinear graphene metasurfaces

    E-Print Network [OSTI]

    Smirnova, Daria A; Kivshar, Yuri S; Khanikaev, Alexander B

    2015-01-01

    We introduce the concept of nonlinear graphene metasurfaces employing the controllable interaction between a graphene layer and a planar metamaterial. Such hybrid metasurfaces support two types of subradiant resonant modes, asymmetric modes of structured metamaterial elements ("metamolecules") and graphene plasmons exhibiting strong mutual coupling and avoided dispersion crossing. High tunability of graphene plasmons facilitates strong interaction between the subradiant modes, modifying the spectral position and lifetime of the associated Fano resonances. We demonstrate that strong resonant interaction, combined with the subwavelength localization of plasmons, leads to the enhanced nonlinear response and high efficiency of the second-harmonic generation.

  8. Thermal Properties of Graphene-Copper-Graphene Heterogeneous Pradyumna Goli,

    E-Print Network [OSTI]

    Thermal Properties of Graphene-Copper-Graphene Heterogeneous Films Pradyumna Goli, Hao Ning that gra- phene-Cu-graphene heterogeneous films reveal strongly enhanced thermal conductivity as compared to the reference Cu and annealed Cu films. Chemical vapor deposition of a single atomic plane of graphene on both

  9. 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

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

    SciTech Connect (OSTI)

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

    2012-06-11

    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.

  11. symposium summary: Island biogeography

    E-Print Network [OSTI]

    Triantis, Kostas A.

    2011-01-01

    aspects of the island systems that were not  considered  in variation across island systems.   However,  island  area system  under  study  is  highly  pre? dictable  from  the  pre?extinction  composition  of  communities,  with  island 

  12. Stretchable Graphene Barriers for Organic Optoelectronic Devices

    E-Print Network [OSTI]

    Kong, Casey

    2015-01-01

    buckling of monolayer graphene on a stretchable substrate.B. & Peeters, F. M. Graphene: A perfect nanoballoon. Appl.Yoon, H. W. & Park, H. B. Graphene and graphene oxide and

  13. Emergent gravity in graphene

    E-Print Network [OSTI]

    M. A. Zubkov; G. E. Volovik

    2013-08-09

    We reconsider monolayer graphene in the presence of elastic deformations. It is described by the tight - binding model with varying hopping parameters. We demonstrate, that the fermionic quasiparticles propagate in the emergent 2D Weitzenbock geometry and in the presence of the emergent U(1) gauge field. Both emergent geometry and the gauge field are defined by the elastic deformation of graphene.

  14. Ultrathin Planar Graphene Supercapacitors

    SciTech Connect (OSTI)

    Huang, Jingsong; Meunier, Vincent; Sumpter, Bobby G; Ajayan, Pullikel M; Yoo, Jung Joon; Balakrishnan, Kaushik; Srivastava, Anchal; Conway, Michelle; Reddy, Arava Leela Mohan; Yu, Jin; Vajtai, Robert

    2011-01-01

    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.

  15. Thermal Transport in Graphene Multilayers and Nanoribbons

    E-Print Network [OSTI]

    Subrina, Samia

    2011-01-01

    in semiconductor device structures with graphene layersconventional semiconductor device structures with graphenemetal-oxide semiconductor (CMOS) technology. Graphene is an

  16. 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.

    2009-01-01

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

  17. Substrate-induced band gap opening in epitaxial graphene

    E-Print Network [OSTI]

    2008-01-01

    step to make graphene a semiconductor is to dope grapheneDirac points, graphene is a zero gap semiconductor, and howconventional semiconductors. In single layer graphene, the

  18. US Virgin Islands-Energy Development in Island Nations (EDIN...

    Open Energy Info (EERE)

    US Virgin Islands-Energy Development in Island Nations (EDIN) Pilot Project Jump to: navigation, search Logo: US Virgin Islands-Energy Development in Island Nations (EDIN) Pilot...

  19. Conductance Quantization of Massless Dirac Fermions and the Synthesis, Characterization, and Manipulation of Graphene

    E-Print Network [OSTI]

    Girit, Caglar

    2010-01-01

    processes in graphene [38]. . . . . . . . . . . . . .Graphene exfoliation and transferiv Bibliography A Graphene Theory A.1 Band

  20. Methanol adsorption on graphene

    E-Print Network [OSTI]

    Schroder, Elsebeth

    2013-01-01

    The adsorption energies and orientation of methanol on graphene are determined from first-principles density functional calculations. We employ the well-tested vdW-DF method that seamlessly includes dispersion interactions with all of the more close-ranged interactions that result in bonds like the covalent and hydrogen bonds. The adsorption of a single methanol molecule and small methanol clusters on graphene are studied at various coverages. Adsorption in clusters or at high coverages (less than a monolayer) is found to be preferable, with the methanol C-O axis approximately parallel to the plane of graphene. The adsorption energies calculated with vdW-DF are compared with previous DFT-D and MP2-based calculations for single methanol adsorption on flakes of graphene (polycyclic aromatic hydrocarbons). For the high coverage adsorption energies we also find reasonably good agreement with previous desorption measurements.

  1. Uncertainties in Gapped Graphene

    E-Print Network [OSTI]

    Eylee Jung; Kwang S. Kim; DaeKil Park

    2012-03-20

    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.

  2. Levitated Spinning Graphene

    E-Print Network [OSTI]

    B. E. Kane

    2010-06-18

    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.

  3. Magnetic Catalysis in Graphene

    E-Print Network [OSTI]

    Christopher Winterowd; Carleton DeTar; Savvas Zafeiropoulos

    2015-09-22

    One of the most important developments in condensed matter physics in recent years has been the discovery and characterization of graphene. A two-dimensional layer of Carbon arranged in a hexagonal lattice, graphene exhibits many interesting electronic properties, most notably that the low energy excitations behave as massless Dirac fermions. These excitations interact strongly via the Coulomb interaction and thus non-perturbative methods are necessary. Using methods borrowed from lattice QCD, we study the graphene effective theory in the presence of an external magnetic field. Graphene, along with other $(2+1)$-dimensional field theories, has been predicted to undergo spontaneous breaking of flavor symmetry including the formation of a gap as a result of the external magnetic field. This phenomenon is known as magnetic catalysis. Our study investigates magnetic catalysis using a fully non-perturbative approach.

  4. 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...

  5. Magnetic Catalysis in Graphene

    E-Print Network [OSTI]

    Winterowd, Christopher; Zafeiropoulos, Savvas

    2015-01-01

    One of the most important developments in condensed matter physics in recent years has been the discovery and characterization of graphene. A two-dimensional layer of Carbon arranged in a hexagonal lattice, graphene exhibits many interesting electronic properties, most notably that the low energy excitations behave as massless Dirac fermions. These excitations interact strongly via the Coulomb interaction and thus non-perturbative methods are necessary. Using methods borrowed from lattice QCD, we study the graphene effective theory in the presence of an external magnetic field. Graphene, along with other $(2+1)$-dimensional field theories, has been predicted to undergo spontaneous breaking of flavor symmetry including the formation of a gap as a result of the external magnetic field. This phenomenon is known as magnetic catalysis. Our study investigates magnetic catalysis using a fully non-perturbative approach.

  6. Faraday rotation in graphene

    E-Print Network [OSTI]

    I. V. Fialkovsky; D. V. Vassilevich

    2012-11-29

    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.

  7. 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)

    2014-10-28

    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.

  8. Twist Solves Bilayer Graphene Mystery

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

    Twist Solves Bilayer Graphene Mystery Print Researchers have discovered a unique new twist to the story of graphene and, in the process, appear to have solved a mystery that has...

  9. 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...

  10. Graphene Growth and Device Integration

    E-Print Network [OSTI]

    INVITED P A P E R Graphene Growth and Device Integration This paper describes one of the emerging methods for growing grapheneVthe chemical vapor deposition methodVwhich is based on a catalytic reaction, Fellow IEEE, Robert M. Wallace, Fellow IEEE, and Rodney S. Ruoff ABSTRACT | Graphene has been introduced

  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. 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)

    2014-01-27

    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.

  13. Energy Transition Initiative: Island Energy Snapshot - St. Kitts & Nevis; NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    2015-03-01

    This profile provides a snapshot of the energy landscape of the Federation of St. Christopher (St. Kitts) and Nevis - two islands located in the Leeward Islands in the West Indies.

  14. Small Changes Help Long Island Homeowner Save Big on Energy Costs...

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

    Small Changes Help Long Island Homeowner Save Big on Energy Costs Small Changes Help Long Island Homeowner Save Big on Energy Costs April 16, 2013 - 12:20pm Addthis Located near...

  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)

    2014-03-10

    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. 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.

  17. Pacific Island Energy Snapshots

    Broader source: Energy.gov [DOE]

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

  18. Caribbean 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.

  19. 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

    2013-04-02

    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.

  20. Thermal Transport in Graphene Multilayers and Nanoribbons

    E-Print Network [OSTI]

    Subrina, Samia

    2011-01-01

    14 Preparation of Graphene . . . . . . . . . . . . . . . .touch screens. 2.3 PREPARATION OF GRAPHENE Since graphene isgraphene might be more advantageous since FLG gives greater flexibility with the sample preparation and

  1. 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;

  2. Symmetry Breaking in Few Layer Graphene Films

    E-Print Network [OSTI]

    2008-01-01

    Molecular doping of graphene. cond-mat/0703390, 2007. [16] Aelectronic dynamics from graphene to graphite. Bull. Amer.carrier lifetime in graphene. cond-mat, page 0612345, 2006.

  3. Graphene-Base Hot-Electron Transistor

    E-Print Network [OSTI]

    Zeng, Caifu

    2014-01-01

    B. H. ; Wang, K. L. "Vertical Graphene-Base Hot-Electronoperation in single-layer graphene ferroelectric memory",of Dirac Point Energy at the Graphene/Oxide Interface", Nano

  4. Carbon Nanotube and Graphene Nanoelectromechanical Systems

    E-Print Network [OSTI]

    Aleman, Benjamin Jose

    2011-01-01

    for transfer-free suspended graphene membrane fabrication on95 7.2 Lithographically de?ned graphene TEM sampleMicroscopy Image of Graphene and Schematic of Structural

  5. Transport Properties of Bilayer Graphene Nanoribbons

    E-Print Network [OSTI]

    Wang, Minsheng

    2013-01-01

    Asymmetry of Graphene p-n Junction. Electron Devices, IEEEFabrication of graphene p-n-p junctions with contactless topof a tilted graphene p-n junction. Physical Review B (

  6. Chemistry at the Dirac Point of Graphene

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01

    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.

  7. Electrical and Thermoelectrical Transport Properties of Graphene

    E-Print Network [OSTI]

    Wang, Deqi

    2011-01-01

    at the interface of semiconductors, graphene is open to anytwo. Graphene is thus a zero band gap semiconductor. FigureHowever, graphene is known as a zero band gap semiconductor,

  8. 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

    2015-01-07

    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...

  9. Graphene Supercapacitors: Charging Up the Future

    E-Print Network [OSTI]

    El-Kady, Maher

    2013-01-01

    8. M. Segal, Selling graphene by the ton. Nat. Nanotechnol.Y. Zhu, J. An, R. S. Ruoff, Graphene-based ultracapacitors.Supercapacitor devices based on graphene materials. J. Phys.

  10. Optimal traps in graphene

    E-Print Network [OSTI]

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

    2015-03-27

    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.

  11. Superradiance Transition in Graphene

    E-Print Network [OSTI]

    Alexander I. Nesterov; Fermín Aceves de la Cruz; Valeriy A. Luchnikov; Gennady P. Berman

    2015-06-12

    We study theoretically and numerically the conditions required for the appearance of a superradiance transition in graphene. The electron properties of graphene are described in the single $p_z$-orbital tight-binding approximation, in which the model is reduced to the effective two-level pseudo-spin $1/2$ system. For each level we introduce the electron transfer rate of escape into a continuum. We demonstrate that, under some conditions, the superradiance experiences the maximal quantum coherent escape to the continuum.

  12. The characterization of Co-nanoparticles supported on graphene

    E-Print Network [OSTI]

    Bazylewski, P; Kukharenko, A I; Kurmaev, E Z; Hunt, A; Moewes, A; Lee, Y H; Cholakh, S O; Chang, G S

    2015-01-01

    The results of density functional theory calculations and measurements using X-ray photoelectron spectroscopy of Co-nanoparticles dispersed on graphene/Cu are presented. It is found that for low cobalt thickness (0.02 nm - 0.06 nm) the Co forms islands distributed non-homogeneously which are strongly oxidized under exposure to air to form cobalt oxides. At greater thicknesses up to 2 nm the upper Co-layers are similarly oxidized whereas the lower layers contacting the graphene remain metallic. The measurements indicate a Co2+ oxidation state with no evidence of a 3+ state appearing at any Co thickness, consistent with CoO and Co[OH]2. The results show that thicker Co (2nm) coverage induces the formation of a protective oxide layer while providing the magnetic properties of Co nanoparticles.

  13. Chemistry at the Dirac Point of Graphene

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01

    including atomic spintronics, 255 and superconductivity.of Graphene: Toward Atomic Spintronics Using a Graphene Web.for applications in spintronics, 29-32 and (iii) bulk

  14. Thermal Transport in Graphene Multilayers and Nanoribbons

    E-Print Network [OSTI]

    Subrina, Samia

    2011-01-01

    1 CHAPTER 2 Thermal transport atvalues of graphene’s thermal conductivity and different1 Thermal conductivity : metals and non - metallic

  15. 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...

  16. Electronic Transport in Novel Graphene Nanostructures

    E-Print Network [OSTI]

    Gannett, William Joy

    2012-01-01

    ultrasmooth graphene nanoribbon semiconductors,” Sciencegraphene: Evidence of a two-dimensional wide bandgap semiconductor,”graphene, hBN, and gallium selenide (GaSe), a layered semiconductor

  17. Electrical Transport in Carbon Nanotubes and Graphene

    E-Print Network [OSTI]

    Liu, Gang

    2010-01-01

    2001), graphene (Miao et al. , 2007), and semiconductorzero. So graphene is zero band gap semiconductor. At the lowgraphene may potentially replace silicon in the semiconductor

  18. Chemistry at the Dirac Point of Graphene

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01

    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 ?-

  19. 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...

  20. 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...

  1. Crown ethers in graphene

    SciTech Connect (OSTI)

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I; Gallego, Nidia C; Pantelides, Sokrates T.; Pennycook, Stephen J; Moyer, Bruce A; Chisholm, Matthew F

    2014-01-01

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basic structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.

  2. Magnetic quantization in multilayer graphenes

    E-Print Network [OSTI]

    Lin, Chiun-Yan; Ou, Yih-Jon; Chiu, Yu-Huang; Lin, Ming-Fa

    2015-01-01

    Essential properties of multilayer graphenes are diversified by the number of layers and the stacking configurations. For an $N$-layer system, Landau levels are divided into $N$ groups, with each identified by a dominant sublattice associated with the stacking configuration. We focus on the main characteristics of Landau levels, including the degeneracy, wave functions, quantum numbers, onset energies, field-dependent energy spectra, semiconductor-metal transitions, and crossing patterns, which are reflected in the magneto-optical spectroscopy, scanning tunneling spectroscopy, and quantum transport experiments. The Landau levels in AA-stacked graphene are responsible for multiple Dirac cones, while in AB-stacked graphene the Dirac properties depend on the number of graphene layers, and in ABC-stacked graphene the low-lying levels are related to surface states. The Landau-level mixing leads to anticrossings patterns in energy spectra, which are seen for intergroup Landau levels in AB-stacked graphene, while in...

  3. 2D Dirac Materials: From Graphene to Topological Insulators

    E-Print Network [OSTI]

    Teweldebrhan, Desalegne Bekuretsion

    2011-01-01

    x Graphene Preparation and2008). Chapter 3 Graphene Preparation and CharacterizationPreparation Methods of Atomically-Thin 2D Graphene . . . . . . . . . . . . . . .

  4. Structural Characterization, Manipulation, and Properties of Graphene Membranes

    E-Print Network [OSTI]

    Kim, Kwanpyo

    2012-01-01

    Si substrate. . . . Figure 2.6 Preparation of graphene TEMlayer graphene preparation. . . . . . . . . . . .Figure 3.1S. Ruoff, Preparation and characterization of graphene oxide

  5. Spin Transport and Relaxation in Graphene and Germanium

    E-Print Network [OSTI]

    Han, Wei

    2011-01-01

    steps: 3.1.1 Preparation of the graphene The graphene areKawakami, in preparation. 9.1 Introduction Graphene is

  6. Mechanical and Electrical Properties of Modified Graphene Devices

    E-Print Network [OSTI]

    ZHANG, HANG

    2012-01-01

    in detail sample (graphene) preparation, localization and20 3.1 Sample (graphene) preparation, localization and3.2. 3.1 Sample (graphene) preparation, localization and

  7. Structural Characterization, Manipulation, and Properties of Graphene Membranes

    E-Print Network [OSTI]

    Kim, Kwanpyo

    2012-01-01

    atomic structure of graphene lattice. . . . . . . . . . .GB) identification through diffraction series on a grapheneFigure 4.2 Imaging of a graphene GB via TEM dark field

  8. Experimental Studies of Oxide Magnetic Tunnel Junctions and Graphene

    E-Print Network [OSTI]

    Liu, Xinfei

    2012-01-01

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

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

    E-Print Network [OSTI]

    Zhang, Yuanbo

    2010-01-01

    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

  10. Mechanical and Electrical Properties of Modified Graphene Devices

    E-Print Network [OSTI]

    ZHANG, HANG

    2012-01-01

    works demonstrate that modified graphene structures providehttp://en.wikipedia.org/wiki/Graphene#Potential_applicationsin detail sample (graphene) preparation, localization and

  11. ORNL demonstrates first large-scale graphene fabrication | ornl...

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

    ORNL demonstrates first large-scale graphene composite fabrication ORNL's ultrastrong graphene features layers of graphene and polymers and is an effective conductor of...

  12. Graphene as the Ultimate Membrane for Gas Separation

    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...

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

    E-Print Network [OSTI]

    LIN, JIAN

    2011-01-01

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

  14. Mechanical and Electrical Properties of Modified Graphene Devices

    E-Print Network [OSTI]

    ZHANG, HANG

    2012-01-01

    as a gapless semiconductor, graphene cannot be directlywith traditional semiconductor materials, graphene hassince graphene is a gapless semiconductor, it cannot be

  15. Spin Transport and Relaxation in Graphene and Germanium

    E-Print Network [OSTI]

    Han, Wei

    2011-01-01

    metals, semiconductors, organics to graphene . . . . . . . .from metals, semiconductors, organics to graphene Fig. 1-4,semiconductor, and carbon-based materials are reviewed. A brief introduction to graphene

  16. Graphene-Based Surface Plasmon-Polaritons for Terahertz Applications

    E-Print Network [OSTI]

    Gu, Xuefeng

    2013-01-01

    efficient excitation of graphene-metal SPP mode using narrowwith the advancement of graphene fabrication technology, ourOF CALIFORNIA Los Angeles Graphene-Based Surface Plasmon-

  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. 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 catalytic systems.12,13 On the other hand, the reduced graphene oxide (rGO) is functionalized graphene Laboratory (PAL), Pohang 790-784, Republic of Korea ABSTRACT: The capacities of graphene oxide (GO

  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. Effect of energetic electron irradiation on graphene and graphene field-effect transistors

    E-Print Network [OSTI]

    Chen, Yong P.

    in the semiconductor substrate supporting graphene. The electrons travel through the substrate and can reachEffect of energetic electron irradiation on graphene and graphene field-effect transistors Isaac transport properties of graphene and the operation of graphene field-effect transistors (GFET). Exposure

  1. 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

  2. GRAPHENE FLAGSHIP, 28 Jan 2013 Graphene appointed an EU Future Emerging Technology flagship

    E-Print Network [OSTI]

    GRAPHENE FLAGSHIP, 28 Jan 2013 Graphene appointed an EU Future Emerging Technology flagship The European Commission has chosen Graphene as one of Europe's first 10-year, 1,000 million euro FET flagships. The mission of Graphene is to take graphene and related layered materials from academic laboratories

  3. Dry-cleaning of graphene

    SciTech Connect (OSTI)

    Algara-Siller, Gerardo; Lehtinen, Ossi; Kaiser, Ute; Turchanin, Andrey

    2014-04-14

    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.

  4. Magnetic Edge States in Graphene

    E-Print Network [OSTI]

    Gabriela Murguia

    2010-08-29

    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.

  5. Twist Solves Bilayer Graphene Mystery

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

    the highest room-temperature mobility of any material, making it a very attractive material for future semiconductor devices. A major drawback, however, is graphene's lack of a...

  6. Bilayer Graphene Gets a Bandgap

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

    displacement field is applied to the two layers; the material then behaves like a semiconductor. A team of researchers from Berkeley has engineered a bandgap in bilayer graphene...

  7. Magnetic Edge States in Graphene

    E-Print Network [OSTI]

    Murguia, Gabriela

    2010-01-01

    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.

  8. 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...

  9. Island Energy Snapshots

    Broader source: Energy.gov [DOE]

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

  10. Energy Transition Initiative: Island Energy Snapshot - Dominica (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2015-03-01

    This profile provides a snapshot of the energy landscape of the Commonwealth of Dominica, an island nation located southeast of Guadeloupe and northwest of Martinique in the Lesser Antilles.

  11. Monsoon surges trigger oceanic eddy formation and propagation in the lee of the Philippine Islands

    E-Print Network [OSTI]

    with eddies that form in the lee of the Cabo Verde and Canary Islands [Chavanne et al., 2002; Sangra et al., 2007]. The Hawaii, Cabo Verde and Canary Islands are located in the trades where winds have typicalMonsoon surges trigger oceanic eddy formation and propagation in the lee of the Philippine Islands

  12. Following more than 30 years of seismic and volcanic quiescence, the Canary Islands

    E-Print Network [OSTI]

    Sleeman, Reinoud

    Following more than 30 years of seismic and volcanic quiescence, the Canary Islands region located History Several eruptions have taken place in the Canary Islands in the last 500 years, all of them, TRANSACTIONS, AMERICAN GEOPHYSICAL UNION PAGES 61,65 Monitoring the Reawakening of Canary Islands'Teide Volcano

  13. Technical Note Graphene: Substrate preparation and introduction

    E-Print Network [OSTI]

    Technical Note Graphene: Substrate preparation and introduction Radosav S. Pantelic a , Ji Won Suk September 2010 Accepted 4 October 2010 Available online xxxx Keywords: Graphene Graphene oxide Cryo the transfer of continuous, single-layer, pristine graphene to standard Quan- tifoil TEM grids. We compare

  14. RAMAN SPECTROSCOPY OF GRAPHENE AND RELATED MATERIALS

    E-Print Network [OSTI]

    Chen, Yong P.

    structure of graphene. (b) Graphene is a zero-gap semiconductor. Its 2-D nature leads to a linear dispersionChapter 19 RAMAN SPECTROSCOPY OF GRAPHENE AND RELATED MATERIALS Isaac Childres*a,b , Luis A This chapter is a review of the application of Raman spectroscopy in characterizing the properties of graphene

  15. 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

  16. 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 Sciences, Tel Aviv University, Tel Aviv 69978, Israel ABSTRACT: The anchoring of benzene molecules-metallic due to charge transfer from the adatom to the electronic system. Upon benzene adsorption, the lithium

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

    E-Print Network [OSTI]

    Pleskot, Dennis

    2013-01-01

    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

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

    E-Print Network [OSTI]

    Nair, Nityan

    2013-01-01

    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 ...

  19. Molecular Phylogenetics and Evolution 43 (2007) 685692 www.elsevier.com/locate/ympev

    E-Print Network [OSTI]

    Posada, David

    2007-01-01

    Ocean islands. In fact, they can be found on essentially every Indian Ocean archipelago: the Comoros species, P. parkeri (Loveridge, 1941). The Comoro islands, a set of four major volcanic islands located in the case of P. dubia), can be found on the Comoros (Glaw and Vences, 1994). This species abundance

  20. Spin caloritronics in graphene

    SciTech Connect (OSTI)

    Ghosh, Angsula; Frota, H. O.

    2015-06-14

    Spin caloritronics, the combination of spintronics with thermoelectrics, exploiting both the intrinsic spin of the electron and its associated magnetic moment in addition to its fundamental electronic charge and temperature, is an emerging technology mainly in the development of low-power-consumption technology. In this work, we study the thermoelectric properties of a Rashba dot attached to two single layer/bilayer graphene sheets as leads. The temperature difference on the two graphene leads induces a spin current, which depends on the temperature and chemical potential. We demonstrate that the Rashba dot behaves as a spin filter for selected values of the chemical potential and is able to filter electrons by their spin orientation. The spin thermopower has also been studied where the effects of the chemical potential, temperature, and also the Rashba term have been observed.

  1. Spin Transport and Relaxation in Graphene and Germanium

    E-Print Network [OSTI]

    Han, Wei

    2011-01-01

    1 1.1 Spintronics . . . . . . . .spintronics . . . . . . . . . . . . . . . . . . . . . . . . . .work on graphene spintronics . . . . . . . . . . .

  2. Graphene Device Fabrication and Applications in Communication Systems

    E-Print Network [OSTI]

    Liu, Guanxiong

    2012-01-01

    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

  3. Coulomb impurity in graphene

    E-Print Network [OSTI]

    Biswas, Rudro R; Son, Dam T

    2007-01-01

    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.

  4. Turbulent flow in graphene

    E-Print Network [OSTI]

    Kumar S. Gupta; Siddhartha Sen

    2010-06-05

    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.

  5. Coulomb impurity in graphene

    E-Print Network [OSTI]

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

    2007-11-29

    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.

  6. Quantum Field Theory in Graphene

    E-Print Network [OSTI]

    I. V. Fialkovsky; D. V. Vassilevich

    2011-11-18

    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.

  7. Electronic and Magneto-electronic Properties of Nanopatterned and Multilayered Graphene

    E-Print Network [OSTI]

    Ahsan, Sonia

    2013-01-01

    Armchair Graphene Nano Ribbon (AGNR) . . . . . . .Engineering and Quantum transport in Graphene TheoreticalStacked Armchair graphene nanoribbon (s-AGNR) . . . . . .

  8. Synthesis and Applications of Large Area Graphene-Based Electrode Systems

    E-Print Network [OSTI]

    Paul, Rajat Kanti

    2011-01-01

    ultrasmooth graphene nanoribbon semiconductors. Sciencedensity of p-type semiconductor graphene upon adsorption thepolycrystalline graphene films with semiconductor properties

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

    E-Print Network [OSTI]

    Guo, Shirui

    2012-01-01

    ultrasmooth graphene nanoribbon semiconductors" Scienceultrasmooth graphene nanoribbon semiconductors" ScienceIndividual Semiconductor Nanocrystals to Graphene" Acs Nano

  10. 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)

    2014-01-13

    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.

  11. Graphene Device Fabrication and Applications in Communication Systems

    E-Print Network [OSTI]

    Liu, Guanxiong

    2012-01-01

    Device Fabrications 2.1 Graphene Samples Preparation We use2.1 Graphene samples preparation ……………………………………………….. 2.2 E-

  12. 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

  13. Quantum Critical Behaviour in a Graphene-like Model

    E-Print Network [OSTI]

    Simon Hands; Costas Strouthos

    2008-06-30

    We present the first results of numerical simulations of a 2+1 dimensional fermion field theory based on a recent proposal for a model of graphene, consisting of N_f four-component Dirac fermions moving in the plane and interacting via an instantaneous Coulomb interaction. In the strong-coupling limit we identify a critical number of flavors N_fc=4.8(2) separating an insulating from a conducting phase. This transition corresponds to the location of a quantum critical point, and we use a fit to the equation of state for the chiral order parameter to estimate the critical exponents. Next we simulate N_f=2 corresponding to real graphene, and approximately locate a transition from strong to weak coupling behaviour. Strong correlations are evident in the weak-coupling regime.

  14. Catalina Island Soapstone Manufacture

    E-Print Network [OSTI]

    Wlodarski, Robert J

    1979-01-01

    Catalina Island Soapstone Manufacture ROBERT J. WLODARSKIsome artifact of native manufacture. That stone is a "hard"Peabody Museum. Method and Manufacture of Several Articles

  15. Smart antennas based on graphene

    SciTech Connect (OSTI)

    Aldrigo, Martino; Dragoman, Mircea; Dragoman, Daniela

    2014-09-21

    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.

  16. Phonon dispersion in graphene

    E-Print Network [OSTI]

    L. A. Falkovsky

    2007-08-11

    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.

  17. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit the followingConcentratingPortal Controlling FoamingControlling Graphene's

  18. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFESOpportunitiesNERSC GettingGraphene's 3D Counterpart Print ALS

  19. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Low LETUsefulJorgeAtlDayGraphene's 3D Counterpart Print

  20. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Low LETUsefulJorgeAtlDayGraphene's 3D Counterpart

  1. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Low LETUsefulJorgeAtlDayGraphene's 3D

  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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Low LETUsefulJorgeAtlDayGraphene's 3DGraphene's 3D

  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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Low LETUsefulJorgeAtlDayGraphene's 3DGraphene's

  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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-Dose Low LETUsefulJorgeAtlDayGraphene's

  5. Polysaccharide Nanocomposites Reinforced with Graphene Oxide and Keratin-Grafted Graphene Oxide

    E-Print Network [OSTI]

    Polysaccharide Nanocomposites Reinforced with Graphene Oxide and Keratin-Grafted Graphene Oxide, chitosan-starch, and carboxymethyl cellulose-starch reinforced with graphene oxide and graphene grafted with keratin were developed. Composites films had been prepared for the casting/solvent evaporation method

  6. Thermal properties of graphene and multilayer graphene: Applications in thermal interface materials

    E-Print Network [OSTI]

    Thermal properties of graphene and multilayer graphene: Applications in thermal interface materials 2012 Accepted by L. Bery Available online 25 April 2012 Keywords: A. Graphene A. Thermal interface materials C. Graphene composites D. Thermal properties a b s t r a c t We review the thermal properties

  7. Transport spectroscopy of disordered graphene quantum dots etched into a single graphene flake

    E-Print Network [OSTI]

    Zumbühl, Dominik

    Transport spectroscopy of disordered graphene quantum dots etched into a single graphene flake of sizes 45, 60 and 80 nm etched with an Ar/O2-plasma into a single graphene sheet, allowing a size comparison avoiding effects from different graphene flakes. The transport gaps and addition energies increase

  8. 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

  9. SURFACE REMEDIATION IN THE ALEUTIAN ISLANDS: A CASE STUDY OF AMCHITKA ISLAND, ALASKA

    SciTech Connect (OSTI)

    Giblin, M. O.; Stahl, D. C.; Bechtel, J. A.

    2002-02-25

    Amchitka Island, Alaska, was at one time an integral player in the nation's defense program. Located in the North Pacific Ocean in the Aleutian Island archipelago, the island was intermittently inhabited by several key government agencies, including the U.S. Army, the U.S. Atomic Energy Commission (predecessor agency to the U.S. Department of Energy), and the U.S. Navy. Since 1993, the U.S. Department of Energy (DOE) has conducted extensive investigations on Amchitka to determine the nature and extent of contamination resulting from historic nuclear testing. The uninhabited island was the site of three high-yield nuclear tests from 1965 to 1971. These test locations are now part of the DOE's National Nuclear Security Administration Nevada Operations Office's Environmental Management Program. In the summer of 2001, the DOE launched a large-scale remediation effort on Amchitka to perform agreed-upon corrective actions to the surface of the island. Due to the lack of resources available on Amchitka and logistical difficulties with conducting work at such a remote location, the DOE partnered with the Navy and U.S. Army Corps of Engineers (USACE) to share certain specified costs and resources. Attempting to negotiate the partnerships while organizing and implementing the surface remediation on Amchitka proved to be a challenging endeavor. The DOE was faced with unexpected changes in Navy and USACE scope of work, accelerations in schedules, and risks associated with construction costs at such a remote location. Unfavorable weather conditions also proved to be a constant factor, often slowing the progress of work. The Amchitka Island remediation project experience has allowed the DOE to gain valuable insights into how to anticipate and mitigate potential problems associated with future remediation projects. These lessons learned will help the DOE in conducting future work more efficiently, and can also serve as a guide for other agencies performing similar work.

  10. Surface functionalization of graphene devices

    E-Print Network [OSTI]

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

    2012-01-01

    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 ...

  11. CONTRIBUTED Variability Effects in Graphene

    E-Print Network [OSTI]

    , which form a critical issue in examining the feasibility of graphene devices for large-scale production has shown its potential in wafer-scale radio- frequency analog circuits [16]­[23], broadband photo

  12. Chiral Gauge Theory for Graphene

    E-Print Network [OSTI]

    R. Jackiw; S. -Y. Pi

    2007-05-04

    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.

  13. Coulomb Drag Mechanisms in Graphene

    E-Print Network [OSTI]

    Abanin, D. A.

    Recent measurements revealed an anomalous Coulomb drag in graphene, hinting at new physics at charge neutrality. The anomalous drag is explained by a new mechanism based on energy transport, which involves interlayer energy ...

  14. Four Dimensional Graphene

    E-Print Network [OSTI]

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

    2011-06-26

    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.

  15. 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 ...

  16. 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 ...

  17. 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)

    2014-06-02

    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.

  18. 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 ...

  19. 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 ...

  20. Studies of bilayer and trilayer graphene

    E-Print Network [OSTI]

    Cela, Devin Artan

    2013-01-01

    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 ...

  1. Chemistry at the Dirac Point of Graphene

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01

    a consequence graphene is a zero-band-gap semiconductor, andGraphene is now on the International Roadmap for Semiconductorsgraphene is referred to as a zero band gap semiconductor,

  2. Disorder-free sputtering method on graphene

    SciTech Connect (OSTI)

    Qiu Xue Peng; Shin Young Jun; Niu Jing; Kulothungasagaran, Narayanapillai; Kalon, Gopinadhan; Yang, Hyunsoo; Qiu Caiyu; Yu Ting

    2012-09-15

    Deposition of various materials onto graphene without causing any disorder is highly desirable for graphene applications. Especially, sputtering is a versatile technique to deposit various metals and insulators for spintronics, and indium tin oxide to make transparent devices. However, the sputtering process causes damage to graphene because of high energy sputtered atoms. By flipping the substrate and using a high Ar pressure, we demonstrate that the level of damage to graphene can be reduced or eliminated in dc, rf, and reactive sputtering processes.

  3. Adsorbing H?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)

    2014-09-14

    The electronic structure of pristine graphene sheet and the resulting structure of adsorbing a single molecule of H?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?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?S on top site opens a gap of 0.3 eV around the symmetry point K. We find that adsorbed H?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?S–graphene for three different cases, we find a significant influence of the location of the H?S molecule on the electronic properties especially the strong hybridization between H?S molecule and graphene sheet.

  4. Graphene Growth on Low Carbon Solubility Metals

    E-Print Network [OSTI]

    Wofford, Joseph Monroe

    2012-01-01

    preparation of Cu substrates will lead to larger grapheneGraphene Growth on Cu(100), Cu(111), and Au(111) Substrate selection and preparationGraphene Growth on Cu(100), Cu(111), and Au(111) 3.1 Substrate selection and preparation

  5. Patterning of graphene Wenbin Li,b

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    Patterning of graphene Ji Feng,a Wenbin Li,b Xiaofeng Qian,b Jingshan Qi,c Liang Qib and Ju Li of carbon (graphene, graphane, etc.) are amenable to unique patterning schemes such as cutting, bending theoretical understanding and processing routes for patterning graphene and highlight potential applications

  6. 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

  7. Approaching ballistic transport in suspended graphene

    E-Print Network [OSTI]

    Andrei, Eva Y.

    Approaching ballistic transport in suspended graphene XU DU, IVAN SKACHKO, ANTHONY BARKER AND EVA Y July 2008; doi:10.1038/nnano.2008.199 The discovery of graphene1,2 raises the prospect of a new class at low densities, the carrier mobility in graphene can remain high, even when their density vanishes

  8. 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

  9. 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

  10. 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

  11. 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

  12. Bound States in Graphene

    E-Print Network [OSTI]

    Kumar S. Gupta; Siddhartha Sen

    2008-06-03

    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.

  13. Magnetic Graphene Nanohole Superlattices

    E-Print Network [OSTI]

    Yu, Decai; Liu, Miao; Liu, Wei; Liu, Feng

    2008-01-01

    We investigate the magnetic properties of nano-holes (NHs) patterned in graphene using first principles calculations. We show that superlattices consisting of a periodic array of NHs form a new family of 2D crystalline "bulk" magnets whose collective magnetic behavior is governed by inter-NH spin-spin interaction. They exhibit long-range magnetic order well above room temperature. Furthermore, magnetic semiconductors can be made by doping magnetic NHs into semiconducting NH superlattices. Our findings offer a new material system for fundamental studies of spin-spin interaction and magnetic ordering in low dimensions, and open up the exciting opportunities of making engineered magnetic materials for storage media and spintronics applications.

  14. Charging Graphene for Energy Storage

    SciTech Connect (OSTI)

    Liu, Jun

    2014-10-06

    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.

  15. 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

  16. 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

  17. 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)

    2013-11-15

    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.

  18. Relativistic graphene ratchet on semidisk Galton board

    E-Print Network [OSTI]

    Leonardo Ermann; Dima L. Shepelyansky

    2010-11-17

    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.

  19. 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

    2013-06-18

    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.

  20. 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

  1. Island Tools and Trainings

    Office of Energy Efficiency and Renewable Energy (EERE)

    Islands can use the tools below to gather data for decision makers and run scenarios on potential energy investments. Tailored trainings provide in-person, onsite guidance and best practices for implementing clean energy solutions.

  2. Island Wide Management Corporation

    Office of Legacy Management (LM)

    9 1986 Island Wide Management Corporation 3000 Marcus Avenue Lake Success, New York 11042 Dear Sir or Madam: I am sending you this letter and the enclosed information as you have...

  3. 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)

    2014-07-14

    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.

  4. Graphene-Based Optical Biosensors and Imaging

    SciTech Connect (OSTI)

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

    2014-01-13

    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.

  5. Counting molecular-beam grown graphene layers

    SciTech Connect (OSTI)

    Plaut, Annette S.; Wurstbauer, Ulrich; Pinczuk, Aron; Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 ; Garcia, Jorge M.; Pfeiffer, Loren N.

    2013-06-17

    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. Urban Surfaces and Heat Island Mitigation Potentials

    E-Print Network [OSTI]

    Akbari, Hashem

    2008-01-01

    Finster. 2000. “The Urban Heat Island, Photochemical Smog,2001. “EPA/NASA Urban Heat Island Pilot Project,” GlobalSystem Urban Surfaces and Heat Island Mitigation Potentials

  7. book review: Everything changes – especially on islands

    E-Print Network [OSTI]

    Sfenthourakis, Spyros

    2012-01-01

    forth, affecting different island systems at varying rates.clever choice of islands as model systems for their theoryof insular systems around the globe, they select nine island

  8. 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

  9. 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 ...

  10. Substrate-induced band gap opening in epitaxial graphene

    E-Print Network [OSTI]

    2008-01-01

    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.

  11. Self-doping effects in epitaxially grown graphene

    E-Print Network [OSTI]

    Siegel, David A.

    2009-01-01

    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

  12. Many-body interactions in quasi-freestanding graphene

    E-Print Network [OSTI]

    Siegel, David

    2012-01-01

    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(

  13. Engineering Enhanced Thermoelectric Properties in Zigzag Graphene Nanoribbons

    E-Print Network [OSTI]

    Engineering Enhanced Thermoelectric Properties in Zigzag Graphene Nanoribbons Hossein Karamitaheri1 graphene nanoribbons in the presence of extended line defects, substrate impurities and edge roughness of highly efficient nanostructured graphene nanoribbon based thermoelectric devices. PACS numbers: 72.80.Vp

  14. High-throughput Synthesis and Metrology of Graphene Materials

    E-Print Network [OSTI]

    Ghazinejad, Maziar Ghazinejad

    2012-01-01

    adjusted as an in-line graphene measurement technique.fabrication and metrology of graphene materials. Our mainof Large-Area Hybrid Graphene-CNT Architectures 2.1

  15. Adsorption of Carbon, Silicon, and Germanium Adatoms on Graphene Sheet

    E-Print Network [OSTI]

    Cahyadi, Erica

    2012-01-01

    tunable bandgap in bilayer graphene. Nature 459: 820-23 (Can silicon behave like graphene? A first-principles study.IVA group atoms adsorption on graphene. J. Appl. Phys. 107,

  16. & Vesicles |Hot Paper| Unilamellar Vesicles from Amphiphilic Graphene Quantum Dots

    E-Print Network [OSTI]

    Jelinek, Raz

    & Vesicles |Hot Paper| Unilamellar Vesicles from Amphiphilic Graphene Quantum Dots Sukhendu Nandi] Abstract: Graphene quantum dots (GQDs) have attracted considerable interest due to their unique Graphene quantum dots (GQDs) are carbon nanoparticles con- sisting of crystalline graphitic cores

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

    E-Print Network [OSTI]

    LIN, JIAN

    2011-01-01

    ultrasmooth graphene nanoribbon semiconductors. Science,of semiconductor ZnO nanostructures on large area grapheneSemiconductor Parameter Analyzer. 3.3 Results and Discussion 3.3.1 Growth Kinetic of CVD Graphene

  18. Graphene as tunable contact for high performance thin film transistor

    E-Print Network [OSTI]

    Liu, Yuan

    2015-01-01

    color photodetection using graphene devices coupled with31 Figure 3-1. Schematic illustration of the graphene-IGZO3-4. Scalability and logic applications of graphene-IGZO

  19. Graphene growth with giant domains using chemical vapor deposition

    E-Print Network [OSTI]

    Yong, Virginia; Hahn, H. Thomas

    2011-01-01

    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,

  20. 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...

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

    E-Print Network [OSTI]

    Loginova, Elena

    2010-01-01

    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

  2. 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

    2014-07-21

    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.

  3. Physisorption of Nucleobases on Graphene

    E-Print Network [OSTI]

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

    2007-04-11

    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.

  4. The Schwinger mechanism and graphene

    E-Print Network [OSTI]

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

    2008-09-22

    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.

  5. Electron Effective Mass in Graphene

    E-Print Network [OSTI]

    Viktor Ariel; Amir Natan

    2012-08-12

    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.

  6. 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

  7. Library Locations Locations other than Main Library

    E-Print Network [OSTI]

    Library Locations Locations other than Main Library Example: Feminist Studies HQ1410 .U54 2009 ............................................................2 Central Call Number Main Library Location Main Library Example: Main Library HQ1410 .U54 2009 See Center (ATC) Classroom 1575 Building Operations Main Entrance Map and Imagery Laboratory (MIL

  8. Library Locations Locations other than Main Library

    E-Print Network [OSTI]

    Library Locations Locations other than Main Library Example: Feminist Studies HQ1410 .U54 2009 these from the library catalog: www.library.ucsb.edu/depts/access/howinprocess.html Main: Items located in the Main Library, Davidson Main Serials Reading Area: 2 North Map & Imagery Lab: 1 North Media Collection

  9. Domain walls in gapped graphene

    E-Print Network [OSTI]

    Semenoff, G W; Zhou, Fei

    2015-01-01

    The electronic properties of a particular class of domain walls in gapped graphene are investigated. We show that they can support mid-gap states which are localized in the vicinity of the domain wall and propagate along its length. With a finite density of domain walls, these states can alter the electronic properties of gapped graphene significantly. If the mid-gap band is partially filled,the domain wall can behave like a one-dimensional metal embedded in a semi-conductor, and could potentially be used as a single-channel quantum wire.

  10. Transmission through Biased Graphene Strip

    E-Print Network [OSTI]

    Hocine Bahlouli; El Bouazzaoui Choubabi; Abderrahim El Mouhafid; Ahmed Jellal

    2011-05-26

    We solve the 2D Dirac equation describing graphene in the presence of a linear vector potential. The discretization of the transverse momentum due to the infinite mass boundary condition reduced our 2D Dirac equation to an effective massive 1D Dirac equation with an effective mass equal to the quantized transverse momentum. We use both a numerical Poincare Map approach, based on space discretization of the original Dirac equation, and direct analytical method. These two approaches have been used to study tunneling phenomena through a biased graphene strip. The numerical results generated by the Poincare Map are in complete agreement with the analytical results.

  11. Domain walls in gapped graphene

    E-Print Network [OSTI]

    G. W. Semenoff; V. Semenoff; Fei Zhou

    2008-05-31

    The electronic properties of a particular class of domain walls in gapped graphene are investigated. We show that they can support mid-gap states which are localized in the vicinity of the domain wall and propagate along its length. With a finite density of domain walls, these states can alter the electronic properties of gapped graphene significantly. If the mid-gap band is partially filled,the domain wall can behave like a one-dimensional metal embedded in a semi-conductor, and could potentially be used as a single-channel quantum wire.

  12. Self healing of defected graphene

    SciTech Connect (OSTI)

    Chen, Jianhui; Shi, Tuwan; Cai, Tuocheng; Wu, Xiaosong; Yu, Dapeng [School of Physics, Peking University, Beijing 100871 (China) [School of Physics, Peking University, Beijing 100871 (China); State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871 (China); Xu, Tao; Sun, Litao [SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096 (China)] [SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096 (China)

    2013-03-11

    For electronics applications, defects in graphene are usually undesirable because of their ability to scatter charge carriers, thereby reduce the carrier mobility. It would be extremely useful if the damage can be repaired. In this work, we employ Raman spectroscopy, X-ray photoemission spectroscopy, transmission electron microscopy, and electrical measurements to study defects in graphene introduced by argon plasma bombardment. We have found that majority of these defects can be cured by a simple thermal annealing process. The self-healing is attributed to recombination of mobile carbon adatoms with vacancies. With increasing level of plasma induced damage, the self-healing becomes less effective.

  13. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura|Bilayer Graphene Gets a Bandgap Print Graphene is the

  14. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura|Bilayer Graphene Gets a Bandgap Print Graphene is

  15. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura|Bilayer Graphene Gets a Bandgap Print Graphene

  16. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura|Bilayer Graphene Gets a Bandgap Print GrapheneBilayer

  17. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura|Bilayer Graphene Gets a Bandgap PrintBilayer Graphene

  18. 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)

    2014-04-24

    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.

  19. Graphene-based battery electrodes having continuous flow paths...

    Office of Scientific and Technical Information (OSTI)

    Graphene-based battery electrodes having continuous flow paths Citation Details In-Document Search Title: Graphene-based battery electrodes having continuous flow paths Some...

  20. The Electronic Structure of Single-Layer Graphene

    E-Print Network [OSTI]

    Siegel, David Alan

    2012-01-01

    Range Interactions in Graphene. ” In preparation (2012).Preparation (2011). Invited talks and seminars “Tuning the properties of Dirac Fermions in Graphene

  1. Nanocomposite of graphene and metal oxide materials | OSTI, US...

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

    Nanocomposite of graphene and metal oxide materials Re-direct Destination: Nanocomposite materials comprising a metal oxide bonded to at least one graphene material. The...

  2. Slip-sliding away: graphene nanoscrolls enable slick surfaces...

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

    Schematic of a superlubricity system: gold nanodiamond particles; blue graphene nanoscroll; green underlying graphene on SiO2; black diamond-like carbon interface (image...

  3. 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...

  4. Graphene physics and insulator-metal transition in compressed...

    Office of Scientific and Technical Information (OSTI)

    Graphene physics and insulator-metal transition in compressed hydrogen Title: Graphene physics and insulator-metal transition in compressed hydrogen Authors: Naumov, Ivan I. ;...

  5. Single-valley engineering in graphene superlattices (Journal...

    Office of Scientific and Technical Information (OSTI)

    Single-valley engineering in graphene superlattices This content will become publicly available on June 14, 2016 Prev Next Title: Single-valley engineering in graphene...

  6. Stabilizing Topological Phases in Graphene via Random Adsorption...

    Office of Scientific and Technical Information (OSTI)

    Stabilizing Topological Phases in Graphene via Random Adsorption Prev Next Title: Stabilizing Topological Phases in Graphene via Random Adsorption Authors: Jiang, Hua ; Qiao,...

  7. Suppression of Grain Boundaries in Graphene Growth on Superstructured...

    Office of Scientific and Technical Information (OSTI)

    Suppression of Grain Boundaries in Graphene Growth on Superstructured Mn-Cu(111) Surface Prev Next Title: Suppression of Grain Boundaries in Graphene Growth on...

  8. Microscopic theory of quantum anomalous Hall effect in graphene...

    Office of Scientific and Technical Information (OSTI)

    Microscopic theory of quantum anomalous Hall effect in graphene Prev Next Title: Microscopic theory of quantum anomalous Hall effect in graphene Authors: Qiao, Zhenhua ;...

  9. Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy

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

    graphene to conduct electrical current is 10 to 100 times greater than those in a normal semiconductor like silicon at room temperature. This makes graphene a very promising...

  10. Structural Characterization, Manipulation, and Properties of Graphene Membranes

    E-Print Network [OSTI]

    Kim, Kwanpyo

    2012-01-01

    Biased bilayer graphene: Semiconductor with a gap tunable byultrasmooth graphene nanoribbon semiconductors. Sciencegraphene is semi-metallic with zero bandgap. In contrast, a typical semiconductor

  11. 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

    2010-06-04

    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.

  12. Graphene-Au Nanoparticles Composite-Based Electrochemical Aptamer...

    Office of Scientific and Technical Information (OSTI)

    Graphene-Au Nanoparticles Composite-Based Electrochemical Aptamer Biosensors Citation Details In-Document Search Title: Graphene-Au Nanoparticles Composite-Based Electrochemical...

  13. Method of preparing graphene-sulfur nanocomposites for rechargeable...

    Office of Scientific and Technical Information (OSTI)

    Method of preparing graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes Citation Details In-Document Search Title: Method of preparing graphene-sulfur...

  14. Direct observation of resistive heating at graphene wrinkles...

    Office of Scientific and Technical Information (OSTI)

    Direct observation of resistive heating at graphene wrinkles and grain boundaries Citation Details In-Document Search Title: Direct observation of resistive heating at graphene...

  15. Spiraling Laser Pulses Could Change Nature of Graphene

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

    Spiraling Laser Pulses Could Change Nature of Graphene Spiraling Laser Pulses Could Change Nature of Graphene Simulations Run at NERSC Show It Could Transform from Metal to...

  16. Electrostatic Transfor of Patterned Epitaxial Graphene from SiC...

    Office of Scientific and Technical Information (OSTI)

    Electrostatic Transfor of Patterned Epitaxial Graphene from SiC (001) to Glass. Citation Details In-Document Search Title: Electrostatic Transfor of Patterned Epitaxial Graphene...

  17. Gate-tunable exchange coupling between cobalt clusters on graphene...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Gate-tunable exchange coupling between cobalt clusters on graphene Title: Gate-tunable exchange coupling between cobalt clusters on graphene Authors:...

  18. Graphene-Study, Kaprun, March 27th 2015, noise / ballistics in graphene, B. Plaais 1/80 WP4 -HF Electronics HF-Graphene Electronics

    E-Print Network [OSTI]

    Plaçais, Bernard

    Graphene-Study, Kaprun, March 27th 2015, noise / ballistics in graphene, B. Plaçais 1/80 WP4 - HF Electronics HF-Graphene Electronics noise (L1) ballistic's (L2) (electron-phonon) (Dirac Fermion Optics) Bernard Plaçais placais@lpa.ens.fr #12;Graphene-Study, Kaprun, March 27th 2015, noise / ballistics

  19. Electromagnetic waves reflection, transmission and absorption by graphene - magnetic semiconductor - graphene sandwich-structure in magnetic field: Faraday geometry

    E-Print Network [OSTI]

    Kuzmin, Dmitry A; Shavrov, Vladimir G

    2014-01-01

    Electrodynamic properties of the graphene - magnetic semiconductor - graphene sandwich-structure have been investigated theoretically with taking into account the dissipation processes. Influence of graphene layers on electromagnetic waves propagation in graphene - semi-infinte magnetic semiconductor and graphene - magnetic semiconductor - graphene sandwich-structure has been analyzed. Frequency and field dependences of the reflectance, transmittance and absorbtance of electromagnetic waves by such structure have been calculated. The size effects associated with the thickness of the structure have been analyzed. The possibility of efficient control of electrodynamic properties of graphene - magnetic semiconductor - graphene sandwich structure by an external magnetic field has been shown.

  20. Preliminary interpretation of the upper crustal structure beneath Prince Edward Island

    E-Print Network [OSTI]

    Jones, Alan G.

    during 1983 to aid in the assessment of the geothermal energy potential of the province. At ten locations. For the western part ofthe Island there is a resistive zone which can be identified from the borehole logs as pre gravity anomaly in the region. Key words: magnetotelluric method, geothermal energy, Prince Edward Island

  1. 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

  2. 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

  3. A new golden era in island biogeography

    E-Print Network [OSTI]

    Fernandez-Palacios, Jose Maria; Kueffer, Christoph; Drake, Donald

    2015-01-01

    Insular woodiness on the Canary Islands: a remarkable caseevery five days in the Canary Islands (Martín Esquivel et

  4. Emergent Horava gravity in graphene

    SciTech Connect (OSTI)

    Volovik, G.E.; L. D. Landau Institute for Theoretical Physics, Kosygina 2, 119334 Moscow ; Zubkov, M.A.

    2014-01-15

    First of all, we reconsider the tight-binding model of monolayer graphene, in which the variations of the hopping parameters are allowed. We demonstrate that the emergent 2D Weitzenbock geometry as well as the emergent U(1) gauge field appear. The emergent gauge field is equal to the linear combination of the components of the zweibein. Therefore, we actually deal with the gauge fixed version of the emergent 2+1 D teleparallel gravity. In particular, we work out the case, when the variations of the hopping parameters are due to the elastic deformations, and relate the elastic deformations with the emergent zweibein. Next, we investigate the tight-binding model with the varying intralayer hopping parameters for the multilayer graphene with the ABC stacking. In this case the emergent 2D Weitzenbock geometry and the emergent U(1) gauge field appear as well, and the emergent low energy effective field theory has the anisotropic scaling. -- Highlights: •The tight-binding model for graphene with varying hopping parameters is considered. •The emergent gravity and emergent gauge fields are derived. •For the case of the multilayer graphene we obtain the analogue of Horava gravity with anisotropic scaling.

  5. Graphene tests of Klein phenomena

    E-Print Network [OSTI]

    Stefano De Leo; Pietro Rotelli

    2012-02-07

    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.

  6. PSEG Long Island- Net Metering

    Broader source: Energy.gov [DOE]

    Although PSEG Long Island’s net metering policy is not governed by the State’s net metering law, the provisions are similar to the State law. Net metering is available for residential, non-reside...

  7. Locative Inversion In Cantonese

    E-Print Network [OSTI]

    Mok, Sui-Sang

    1992-01-01

    This paper proposes that locative inversion is a widespread syntactic process in Cantonese. The sentence-initial locative phrases in the Locative Inversion sentences are argued to be subjects which come from the postverbal complement position...

  8. Caustic graphene plasmons with Kelvin angle

    E-Print Network [OSTI]

    Shi, Xihang; Gao, Fei; Xu, Hongyi; Yang, Zhaoju; Zhang, Baile

    2015-01-01

    A century-long argument made by Lord Kelvin that all swimming objects have an effective Mach number of 3, corresponding to the Kelvin angle of 19.5 degree for ship waves, has been recently challenged with the conclusion that the Kelvin angle should gradually transit to the Mach angle as the ship velocity increases. Here we show that a similar phenomenon can happen for graphene plasmons. By analyzing the caustic wave pattern of graphene plasmons stimulated by a swift charged particle moving uniformly above graphene, we show that at low velocities of the charged particle, the caustics of graphene plasmons form the Kelvin angle. At large velocities of the particle, the caustics disappear and the effective semi-angle of the wave pattern approaches the Mach angle. Our study introduces caustic wave theory to the field of graphene plasmonics, and reveals a novel physical picture of graphene plasmon excitation during electron energy-loss spectroscopy measurement.

  9. TE resonances in graphene-dielectric structures

    E-Print Network [OSTI]

    Werra, Julia F M; Busch, Kurt

    2015-01-01

    An investigation of the dispersion relations of TE resonances in different graphene-dielectric structures is presented. When a graphene layer is brought into contact with a dielectric material, a gap can appear in its electric band structure. This allows for the formation of TE-plasmons with unusual dispersion relations. In addition, if the dielectric has a finite thickness, graphene acts as a mode filter and strongly modifies the behavior of the waveguiding modes by introducing a frequency cutoff. This cutoff and the properties of TE-plasmons are closely related to the pair-creation threshold of graphene thus representing quantum mechanical effects that manifest themselves in the electromagnetic response. Our findings are of particular relevance to all forms of light-matter interaction in graphene-based systems, notably for the decay rates of emitters that are in close proximity to graphene.

  10. Long Island Solar Farm

    SciTech Connect (OSTI)

    Anders, R.

    2013-05-01

    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.

  11. Thermal Properties of Graphene and Applications for Thermal Management of High-Power Density Electronics

    E-Print Network [OSTI]

    Yan, Zhong

    2013-01-01

    developed rapidly for graphene preparation. One method is tostructure, graphene sample preparations, Raman spectroscopyProperties of Graphene and Sample Preparation The discovery

  12. Synthesis of Graphene Layers from Metal-Carbon Melts: Nucleation and Growth Kinetics

    E-Print Network [OSTI]

    Amini, Shaahin

    2012-01-01

    59   Single layer graphene preparation1.9.2. Single layer graphene preparation techniques Theretechniques for graphene preparation, above all, three major

  13. An Investigation of Spin and Charge Transport in Doped and Defected Graphene

    E-Print Network [OSTI]

    McCreary, Kathleen M.

    2012-01-01

    hydrogenated epitaxial graphene. Appl. Phys. Lett. 98,of magnetoconductance in graphene devices. Phys. Rev. B 83,carrier mobilities in graphene and its bilayer. Phys. Rev.

  14. Synthesis of Graphene Layers from Metal-Carbon Melts: Nucleation and Growth Kinetics

    E-Print Network [OSTI]

    Amini, Shaahin

    2012-01-01

    in Patterned Epitaxial Graphene, Science, (2006) 1125925. [Large-scale pattern growth of graphene films for stretchableLarge Area, Few-Layer Graphene Films on Arbitrary Substrates

  15. The Theory of Thermal, Thermoelectric and Electrical Transport Properties of Graphene

    E-Print Network [OSTI]

    Ugarte, Vincent Ike

    2010-01-01

    Transport Theory of Graphene in a Weak Magnetic Field 3.11.1.1 Graphene Lattice In Reciprocal Spaceand Graphene . . . . . . . . . . . . . . . . Quantum

  16. Spin waves in zigzag graphene nanoribbons and the stability of edge ferromagnetism

    E-Print Network [OSTI]

    Culchac, F. J.; Latgé, A.; Costa, A. T.

    2011-01-01

    Spin waves in zigzag graphene nanoribbons and the stabilityspin excitations of zigzag graphene nanoribbons of varyingspintronic devices. Abstract. Graphene is being hailed as

  17. Thermal Properties of Graphene and Applications for Thermal Management of High-Power Density Electronics

    E-Print Network [OSTI]

    Yan, Zhong

    2013-01-01

    Noise Reduction in Graphene Transistors: Experiment andand Thermal Properties of Graphene Nanoribbons EncapsulatedGating of Single-layer Graphene with Single- stranded

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

    E-Print Network [OSTI]

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

    2013-01-01

    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.

  19. Thermal Properties of Graphene and Applications for Thermal Management of High-Power Density Electronics

    E-Print Network [OSTI]

    Yan, Zhong

    2013-01-01

    applications of graphene in semiconductor industry. TheGraphene Transistors: Experiment and Modeling-Based Optimization” Semiconductorused in semiconductor industry, which gives graphene a great

  20. Quantum Transport in Misoriented Layers of Graphene: Physics and Device Applications

    E-Print Network [OSTI]

    Habib, K M Masum

    2013-01-01

    Ultra- smooth Graphene Nanoribbon Semiconductors,” Science,Semiconductors (ITRS). Introduction Lack of a bandgap in graphene [graphene. Background and Motivation Driven by Moore’s law, the semiconductor

  1. Graphene-Plasmonic Hybrid Platform for Label-Free SERS Biomedical Detection

    E-Print Network [OSTI]

    Wang, Pu

    2015-01-01

    A. & Avouris, P. Ultrafast graphene photodetector. Nat.101]. Bao, Q. & Loh, K. P. Graphene photonics, plasmonics,Fang, Z. et al. Graphene-antenna sandwich photodetector.

  2. 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)

    2014-02-03

    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.

  3. How Bilayer Graphene Got a Bandgap

    ScienceCinema (OSTI)

    Feng Wang

    2010-01-08

    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.

  4. Electrostatic force assisted deposition of graphene

    DOE Patents [OSTI]

    Liang, Xiaogan (Berkeley, CA)

    2011-11-15

    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.

  5. How Bilayer Graphene Got a Bandgap

    ScienceCinema (OSTI)

    Wang, Feng

    2013-05-29

    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.

  6. Energy Transition Initiative: Island Energy Snapshot - Puerto Rico (Fact Sheet); NREL(National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    2015-03-01

    This profile provides a snapshot of the energy landscape of the Commonwealth of Puerto Rico - a U.S. territory located about 60 miles east of the Dominican Republic and directly west of the U.S. Virgin Islands.

  7. Transport Properties of Bilayer Graphene Nanoribbons

    E-Print Network [OSTI]

    Wang, Minsheng

    2013-01-01

    Electrical spin injection and transport in germanium”. Phys.P. , Temperature- Dependent Transport in Suspended Graphene.Y. M. , Quantum Transport: Introduction to Nanoscience.

  8. Electronic and Spintronic Properties of Graphene

    E-Print Network [OSTI]

    Pi, Keyu

    2010-01-01

    of an area known as spintronics is looking at utilizes thedevices. For graphene spintronics, one of the most importantto the application of spintronics in data storage devices

  9. Electronic and Spintronic Properties of Graphene

    E-Print Network [OSTI]

    Pi, Keyu

    2010-01-01

    Electronic and Spintronic Properties of Graphene by Ke-yu Piproperties and spintronic properties of transition metal45 Chapter 4: Spintronic properties of

  10. Towards Magneto-Logic Gates in Graphene

    E-Print Network [OSTI]

    Wen, Hua

    2014-01-01

    using graphene based spintronic logic gates. Proc. SPIE,applications using spintronic devices for logic operationa leading candidate for spintronic applications due to its

  11. Graphene 'gateway' discovery opens possibilities for improved...

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

    Dawn Levy Communications 865.576.6448 Graphene 'gateway' discovery opens possibilities for improved energy technologies Computer simulations show a single proton (pink) can cross...

  12. 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)

    2014-10-15

    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.

  13. 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)

    2014-03-15

    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.

  14. 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

  15. Graphene Growth on Low Carbon Solubility Metals

    E-Print Network [OSTI]

    Wofford, Joseph Monroe

    2012-01-01

    graphene is both a semimetal and a zero bandgap semiconductorgraphene growth. Ge wafers are also available with the exceptional surface qualities common to semiconductor

  16. Tunable quantum temperature oscillations in graphene nanostructures...

    Office of Scientific and Technical Information (OSTI)

    Tunable quantum temperature oscillations in graphene nanostructures Citation Details In-Document Search This content will become publicly available on March 4, 2016 Title: Tunable...

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

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

    Incorporating graphene, a team of scientists at Pacific Northwest National Laboratory, Vorbeck Materials Corporation, and Princeton University have developed a nanocomposite...

  18. 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)

    2014-03-24

    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.

  19. Accommodation Location(s) Cologne -Ehrenfeld.

    E-Print Network [OSTI]

    Molinari, Marc

    Accommodation Location(s) ­ Cologne - Ehrenfeld. Price of rent ­ Sub-let, cost roughly 300 euros a month inc bills. Organisation of accommodation/gas/electricity/internet/phones ­ Because I lived with Telekom for phone/internet as they just try to rip you off! Germany COLOGNE Language Assistantship Travel

  20. 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

  1. Assateague Island is Changing

    E-Print Network [OSTI]

    Boynton, Walter R.

    and longshore currents closing inlets over time, future breaches and new inlets are inevitable as sea level to shape and move Assateague Island. Former US Coast Guard Station Toms Cove Chincoteague Inlet Atlantic To reduce the National Seashore's carbon footprint and demonstrate the use of alternative energy, solar

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

    SciTech Connect (OSTI)

    Wang, Yu

    2014-10-28

    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.

  3. Electronic structure of graphene oxide and reduced graphene oxide monolayers

    SciTech Connect (OSTI)

    Sutar, D. S.; Singh, Gulbagh; Divakar Botcha, V.

    2012-09-03

    Graphene oxide (GO) monolayers obtained by Langmuir Blodgett route and suitably treated to obtain reduced graphene oxide (RGO) monolayers were studied by photoelectron spectroscopy. Upon reduction of GO to form RGO C1s x-ray photoelectron spectra showed increase in graphitic carbon content, while ultraviolet photoelectron spectra showed increase in intensity corresponding to C2p-{pi} electrons ({approx}3.5 eV). X-ray excited Auger transitions C(KVV) and plasmon energy loss of C1s photoelectrons have been analyzed to elucidate the valence band structure. The effective number of ({pi}+{sigma}) electrons as obtained from energy loss spectra was found to increase by {approx}28% on reduction of GO.

  4. 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

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

    E-Print Network [OSTI]

    Gao, Hongjun

    and spintronics. Keywords¡¡ ¡¡ Graphene, quantum Hall effect, spintronics, devices 3 ... (¯oe..."¯ : 60771037

  6. High Performance Graphene Transistors on Silicon Professor Xu Jianbin

    E-Print Network [OSTI]

    Huang, Jianwei

    High Performance Graphene Transistors on Silicon Professor Xu Jianbin Graphene composed of one nanoelectronics. In particular, the mobility of Graphene, which is a measure of how easily electrons can start for use in post-silicon electronics. However, fabrication of the graphene-based electronic devices

  7. Curling graphene ribbons through thermal annealing Yunhao Cao,1

    E-Print Network [OSTI]

    Wikswo, John

    Curling graphene ribbons through thermal annealing Yunhao Cao,1 Roel L. Flores,2 and Ya-Qiong Xu1 process is developed to curl graphene membranes through thermal annealing. The resulting curled graphene ribbons displayed enhanced photocurrent response compared to flat graphene ribbons. The annealing

  8. 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

  9. Electronic transport in two-dimensional graphene S. Das Sarma

    E-Print Network [OSTI]

    Rossi, Enrico

    . Monolayer graphene 409 2. Bilayer graphene 411 3. 2D Semiconductor structures 412 C. Elementary electronicElectronic transport in two-dimensional graphene S. Das Sarma Condensed Matter Theory Center; published 16 May 2011) A broad review of fundamental electronic properties of two-dimensional graphene

  10. 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

  11. Energy Transition Initiative, Island Energy Snapshot - Turks & Caicos (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2015-02-01

    This profile presents a snapshot of the electricity generation and reduction technologies, including solar hot water heating, available to Turks and Caicos - a British overseas territory consisting of two groups of islands located southeast of the Bahamas. Heating and transportation fuels are not addressed.

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

    SciTech Connect (OSTI)

    2013-09-01

    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.

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

    E-Print Network [OSTI]

    Park, Harold S.

    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

  14. Graphene-based spintronic components

    E-Print Network [OSTI]

    Zeng, Minggang; Su, Haibin; Zhou, Miao; Zhang, Chun; Feng, Yuanping

    2010-01-01

    A major challenge of spintronics is in generating, controlling and detecting spin-polarized current. Manipulation of spin-polarized current, in particular, is difficult. We demonstrate here, based on calculated transport properties of graphene nanoribbons, that nearly +-100% spin-polarized current can be generated in zigzag graphene nanoribbons (ZGNRs) and tuned by a source-drain voltage in the bipolar spin diode, in addition to magnetic configurations of the electrodes. This unusual transport property is attributed to the intrinsic transmission selection rule of the spin subbands near the Fermi level in ZGNRs. The simultaneous control of spin current by the bias voltage and the magnetic configurations of the electrodes provides an opportunity to implement a whole range of spintronics devices. We propose theoretical designs for a complete set of basic spintronic devices, including bipolar spin diode, transistor and logic gates, based on ZGNRs.

  15. Chiral Symmetry Breaking in Graphene

    E-Print Network [OSTI]

    Gordon W. Semenoff

    2011-08-19

    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.

  16. Smooth electron waveguides in graphene

    E-Print Network [OSTI]

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

    2010-06-29

    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.

  17. Emergent Horava gravity in graphene

    E-Print Network [OSTI]

    G. E. Volovik; M. A. Zubkov

    2013-07-07

    First of all, we reconsider the tight - binding model of monolayer graphene, in which the variations of the hopping parameters are allowed. We demonstrate that the emergent 2D Weitzenbock geometry as well as the emergent U(1) gauge field appear. The emergent gauge field is equal to the linear combination of the components of the zweibein. Therefore, we actually deal with the gauge fixed version of the emergent 2+1 D teleparallel gravity. In particular, we work out the case, when the variations of the hopping parameters are due to the elastic deformations, and relate the elastic deformations with the emergent zweibein. Next, we investigate the tight - binding model with the varying intralayer hopping parameters for the multilayer graphene with the ABC stacking. In this case the emergent 2D Weitzenbock geometry and the emergent U(1) gauge field appear as well, the emergent low energy effective field theory has the anisotropic scaling.

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

    E-Print Network [OSTI]

    Guo, Shirui

    2012-01-01

    S. Ruoff,"Preparation and characterization of graphene oxideQian, M. Zhang, F. Wei,"Preparation of a graphene nanosheet/Experimental 4.1.2.1 Preparation of Graphene Oxide Graphene

  19. Broadband electromagnetic response and ultrafast dynamics of few-layer epitaxial graphene

    E-Print Network [OSTI]

    Choi, Hyunyong

    2010-01-01

    of few-layer epitaxial graphene H. Choi, 1 F. Borondics, 2a con?r- mation of graphene’s unusual electrodynamics. ThisLett. 96, 256802 (2006). graphene THz/IR SiC FIG. 1: (Color

  20. Comprehensive Pyrometry of Incandescent Multiwalled Carbon Nanotubes and Graphene in the Visible and Near Infrared

    E-Print Network [OSTI]

    Singer, Scott

    2012-01-01

    Graphene As graphene is a zero-gap semiconductor, transportsemiconductor technology. The performance of grapheneGraphene, an atomically thin sheet of sp 2 bonded carbon, is a zero-bandgap semiconductor

  1. Graphene TE Surface Plasmon Detection using Nonreciprocity Modal Discrimination

    E-Print Network [OSTI]

    Chamanara, Nima

    2015-01-01

    We present a magnetically biased graphene-ferrite structure discriminating the TE and TM plasmonic modes of graphene. In this structure, the graphene TM plasmons interact reciprocally with the structure. In contrast, the graphene TE plasmons exhibit nonreciprocity. This nonreciprocity is manifested in different phases and losses of surface plasmons for opposite directions of propagation. The proposed structure provides a unique platform for the experimental demonstration of the unusual existence of the TE plasmonic mode in graphene.

  2. MOBILE DEVICE LOCATION INFORMATION ACQUISITION FRAMEWORK FOR DEVELOPMENT OF LOCATION

    E-Print Network [OSTI]

    Dustdar, Schahram

    MOBILE DEVICE LOCATION INFORMATION ACQUISITION FRAMEWORK FOR DEVELOPMENT OF LOCATION INFORMATION, 1040 Vienna, Austria dustdar@infosys.tuwien.ac.at Keywords: Mobile device location information, location information based services, location information acquisition. Abstract: Mobile device location

  3. Phonon dispersion of graphene revisited

    SciTech Connect (OSTI)

    Sahoo, Rasmita, E-mail: sahoorasmita@yahoo.com; Mishra, Rashmi Ranjan [Birla Institute of Technology and Science, Department of Physics (India)

    2012-05-15

    The phonon dispersion of graphene is derived by using a simple mass spring model and considering up to the first, second, third, and fourth nearest-neighbor interactions. The results obtained from different nearest-neighbor interactions are compared and it is shown that the k{sup 2} dependence for the out-of-plane transverse acoustic mode obtained in other sophisticated methods as well as experiment occurs only after including the fourth nearest-neighbor interaction.

  4. Helicity -- from Clifford to Graphene

    E-Print Network [OSTI]

    Christian G. Boehmer; Louie Corpe

    2012-03-31

    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.

  5. Graphene, neutrino mass and oscillation

    E-Print Network [OSTI]

    Z. Y. Wang

    2011-03-28

    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.

  6. Quantized conductance of a suspended graphene nanoconstriction

    E-Print Network [OSTI]

    Nikolaos Tombros; Alina Veligura; Juliane Junesch; Marcos H. D. Guimarães; Ivan J. Vera Marun; Harry T. Jonkman; Bart J. van Wees

    2011-05-31

    A yet unexplored area in graphene electronics is the field of quantum ballistic transport through graphene nanostructures. Recent developments in the preparation of high mobility graphene are expected to lead to the experimental verification and/or discovery of many new quantum mechanical effects in this field. Examples are effects due to specific graphene edges, such as spin polarization at zigzag edges of a graphene nanoribbon and the use of the valley degree of freedom in the field of graphene valleytronics8. As a first step in this direction we present the observation of quantized conductance at integer multiples of 2e^2/h at zero magnetic field and 4.2 K temperature in a high mobility suspended graphene ballistic nanoconstriction. This quantization evolves into the typical quantum Hall effect for graphene at magnetic fields above 60mT. Voltage bias spectroscopy reveals an energy spacing of 8 meV between the first two subbands. A pronounced feature at 0.6 2e^2/h present at a magnetic field as low as ~0.2T resembles the "0.7 anomaly" observed in quantum point contacts in a GaAs-AlGaAs two dimensional electron gas, having a possible origin in electron-electron interactions.

  7. Quantized conductance of a suspended graphene nanoconstriction

    E-Print Network [OSTI]

    Tombros, Nikolaos; Junesch, Juliane; Guimarães, Marcos H D; Marun, Ivan J Vera; Jonkman, Harry T; van Wees, Bart J

    2011-01-01

    A yet unexplored area in graphene electronics is the field of quantum ballistic transport through graphene nanostructures. Recent developments in the preparation of high mobility graphene are expected to lead to the experimental verification and/or discovery of many new quantum mechanical effects in this field. Examples are effects due to specific graphene edges, such as spin polarization at zigzag edges of a graphene nanoribbon and the use of the valley degree of freedom in the field of graphene valleytronics8. As a first step in this direction we present the observation of quantized conductance at integer multiples of 2e^2/h at zero magnetic field and 4.2 K temperature in a high mobility suspended graphene ballistic nanoconstriction. This quantization evolves into the typical quantum Hall effect for graphene at magnetic fields above 60mT. Voltage bias spectroscopy reveals an energy spacing of 8 meV between the first two subbands. A pronounced feature at 0.6 2e^2/h present at a magnetic field as low as ~0.2T...

  8. Thermal Conductivity of Graphene Laminate H. Malekpour,

    E-Print Network [OSTI]

    Thermal Conductivity of Graphene Laminate H. Malekpour, K.-H. Chang, J.-C. Chen, C.-Y. Lu, D. L, Manchester, United Kingdom *S Supporting Information ABSTRACT: We have investigated thermal conductivity and a set of suspended samples with the graphene laminate thickness from 9 to 44 m. The thermal conductivity

  9. The Quantum Hall Effect in Graphene

    E-Print Network [OSTI]

    Paolo Cea

    2012-04-24

    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 $\

  10. Pseudospin entanglement and Bell test in graphene

    E-Print Network [OSTI]

    M. Kindermann

    2008-07-03

    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.

  11. Manifestations of topological effects in graphene

    E-Print Network [OSTI]

    Jiannis K. Pachos

    2008-12-05

    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.

  12. The Hawking-Unruh phenomenon on graphene

    E-Print Network [OSTI]

    Alfredo Iorio; Gaetano Lambiase

    2012-09-03

    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.

  13. Silicene: Graphene's silicon cousin Xining Zang

    E-Print Network [OSTI]

    Budker, Dmitry

    Germanene #12;Limit of Moore's Law in Bulk Material To break the limit Single layer 2D graphene Silicene Bandstructure calculated by ab initio #12;Summary · Silicene and germanene 2D semiconductor · HoneycombSilicene: Graphene's silicon cousin Xining Zang Graduate Student ME @Berkeley 05/02/2013 #12

  14. Nanocomposite of graphene and metal oxide materials

    DOE Patents [OSTI]

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

    2012-09-04

    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.

  15. Nanocomposite of graphene and metal oxide materials

    DOE Patents [OSTI]

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

    2013-10-15

    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 10 C.

  16. Electrical Control of Plasmon Resonance with Graphene

    E-Print Network [OSTI]

    Kim, Jonghwan; Cho, David J; Geng, Baisong; Regan, Will; Shi, Sufei; Kim, Kwanpyo; Zettl, Alex; Shen, Yuen-Ron; Wang, Feng

    2015-01-01

    Surface plasmon, with its unique capability to concentrate light into sub-wavelength volume, has enabled great advances in photon science, ranging from nano-antenna and single-molecule Raman scattering to plasmonic waveguide and metamaterials. In many applications it is desirable to control the surface plasmon resonance in situ with electric field. Graphene, with its unique tunable optical properties, provides an ideal material to integrate with nanometallic structures for realizing such control. Here we demonstrate effective modulation of the plasmon resonance in a model system composed of hybrid graphene-gold nanorod structure. Upon electrical gating the strong optical transitions in graphene can be switched on and off, which leads to significant modulation of both the resonance frequency and quality factor of plasmon resonance in gold nanorods. Hybrid graphene-nanometallic structures, as exemplified by this combination of graphene and gold nanorod, provide a general and powerful way for electrical control ...

  17. Intravalley Multiple Scattering of Quasiparticles in Graphene

    E-Print Network [OSTI]

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

    2011-05-28

    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.

  18. Plasmon Resonance in Multilayer Graphene Nanoribbons

    E-Print Network [OSTI]

    Emani, Naresh Kumar; Chung, Ting-Fung; Prokopeva, Ludmila J; Kildishev, Alexander V; Shalaev, Vladimir M; Chen, Yong P; Boltasseva, Alexandra

    2015-01-01

    Plasmon resonance in nanopatterned single layer graphene nanoribbon (SL-GNR), double layer graphene nanoribbon (DL-GNR) and triple layer graphene nanoribbon (TL-GNR) structures is studied both experimentally and by numerical simulations. We use 'realistic' graphene samples in our experiments to identify the key bottle necks in both experiments and theoretical models. The existence of electrical tunable plasmons in such stacked multilayer GNRs was first experimentally verified by infrared microscopy. We find that the strength of the plasmonic resonance increases in DL-GNR when compared to SL-GNRs. However, we do not find a further such increase in TL-GNRs compared to DL-GNRs. We carried out systematic full wave simulations using finite element technique to validate and fit experimental results, and extract the carrier scattering rate as a fitting parameter. The numerical simulations show remarkable agreement with experiments for unpatterned SLG sheet, and a qualitative agreement for patterned graphene sheet. W...

  19. Optimal fault location 

    E-Print Network [OSTI]

    Knezev, Maja

    2008-10-10

    sequence of events newly obtained recording belongs. Software prototype of the proposed automated fault location analysis is developed using Java programming language. Fault location analysis is automatically triggered by appearance of new event files in a...

  20. The ground state construction of bilayer graphene

    E-Print Network [OSTI]

    Alessandro Giuliani; Ian Jauslin

    2015-07-31

    We consider a model of half-filled bilayer graphene, in which the three dominant Slonczewski-Weiss-McClure hopping parameters are retained, in the presence of short range interactions. Under a smallness assumption on the interaction strength $U$ as well as on the inter-layer hopping $\\epsilon$, we construct the ground state in the thermodynamic limit, and prove its analyticity in $U$, uniformly in $\\epsilon$. The interacting Fermi surface is degenerate, and consists of eight Fermi points, two of which are protected by symmetries, while the locations of the other six are renormalized by the interaction, and the effective dispersion relation at the Fermi points is conical. The construction reveals the presence of different energy regimes, where the effective behavior of correlation functions changes qualitatively. The analysis of the crossover between regimes plays an important role in the proof of analyticity and in the uniform control of the radius of convergence. The proof is based on a rigorous implementation of fermionic renormalization group methods, including determinant estimates for the renormalized expansion.

  1. The ground state construction of bilayer graphene

    E-Print Network [OSTI]

    Alessandro Giuliani; Ian Jauslin

    2015-07-22

    We consider a model of half-filled bilayer graphene, in which the three dominant Slonczewski-Weiss-McClure hopping parameters are retained, in the presence of short range interactions. Under a smallness assumption on the interaction strength $U$ as well as on the inter-layer hopping $\\epsilon$, we construct the ground state in the thermodynamic limit, and prove its analyticity in $U$, uniformly in $\\epsilon$. The interacting Fermi surface is degenerate, and consists of eight Fermi points, two of which are protected by symmetries, while the locations of the other six are renormalized by the interaction, and the effective dispersion relation at the Fermi points is conical. The construction reveals the presence of different energy regimes, where the effective behavior of correlation functions changes qualitatively. The analysis of the crossover between regimes plays an important role in the proof of analyticity and in the uniform control of the radius of convergence. The proof is based on a rigorous implementation of fermionic renormalization group methods, including determinant estimates for the renormalized expansion.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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"...

  9. Blue fluorescent organic light emitting diodes with multilayered graphene anode

    SciTech Connect (OSTI)

    Hwang, Joohyun [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Choi, Hong Kyw [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Moon, Jaehyun; Shin, Jin-Wook; Joo, Chul Woong; Han, Jun-Han; Cho, Doo-Hee; Huh, Jin Woo [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Choi, Sung-Yool [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Lee, Jeong-Ik, E-mail: jiklee@etri.re.kr [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Chu, Hye Yong [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)

    2012-10-15

    As an innovative anode for organic light emitting devices (OLEDs), we have investigated graphene films. Graphene has importance due to its huge potential in flexible OLED applications. In this work, graphene films have been catalytically grown and transferred to the glass substrate for OLED fabrications. We have successfully fabricated 2 mm × 2 mm device area blue fluorescent OLEDs with graphene anodes which showed 2.1% of external quantum efficiency at 1000 cd/m{sup 2}. This is the highest value reported among fluorescent OLEDs using graphene anodes. Oxygen plasma treatment on graphene has been found to improve hole injections in low voltage regime, which has been interpreted as oxygen plasma induced work function modification. However, plasma treatment also increases the sheet resistance of graphene, limiting the maximum luminance. In summary, our works demonstrate the practical possibility of graphene as an anode material for OLEDs and suggest a processing route which can be applied to various graphene related devices.

  10. 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)

    2013-10-15

    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.

  11. Strongly Coupled Graphene on the Lattice

    E-Print Network [OSTI]

    Timo A. Lähde; Joaquín E. Drut

    2011-11-03

    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.

  12. Magnetization dynamics of cobalt grown on graphene

    SciTech Connect (OSTI)

    Berger, A. J.; White, S. P.; Adur, R.; Pu, Y.; Hammel, P. C.; Amamou, W.; Kawakami, R. K.

    2014-05-07

    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.

  13. 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

    2013-10-15

    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.

  14. Graphene induced remote surface scattering in graphene/AlGaN/GaN heterostructures

    SciTech Connect (OSTI)

    Liu, Xiwen; Li, Dan; Wang, Bobo; Liu, Bin; Chen, Famin; Jin, Guangri; Lu, Yanwu, E-mail: ywlu@bjtu.edu.cn [Department of Physics, Beijing Jiaotong University, Beijing 100044 (China)

    2014-10-20

    The mobilities of single-layer graphene combined with AlGaN/GaN heterostructures on two-dimensional electron gases in graphene/AlGaN/GaN double heterojunction are calculated. The impact of electron density in single-layer graphene is also studied. Remote surface roughness (RSR) and remote interfacial charge (RIC) scatterings are introduced into this heterostructure. The mobilities limited by RSR and RIC are an order of magnitude higher than that of interface roughness and misfit dislocation. This study contributes to designing structures for generation of higher electron mobility in graphene/AlGaN/GaN double heterojunction.

  15. 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)

    2014-01-27

    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.

  16. Single-Particle Tunneling in Doped Graphene-Insulator-Graphene Junctions R. M. Feenstra*

    E-Print Network [OSTI]

    Feenstra, Randall

    -insulator-graphene (GIG) tunnel junctions. * feenstra@cmu.edu djena@nd.edu ggu1@utk.edu Published in J. Appl. Phys. 111

  17. Diamondization of Graphene and Graphene-BN Bilayers: Chemical Functionalization and Electronic Structure Engineering

    E-Print Network [OSTI]

    Yuan, Long; Yang, Jinlong; Hou, Jian Guo

    2011-01-01

    In this article, based on first-principles calculations, we systematically study functionalization induced diamonization of graphene bilayer and graphene-BN hybrid bilayer. With single-side functionalization, the diamondized structures are magnetic semiconductor. Interestingly, if both sides of the bilayer are functionalized, diamondization becomes spontaneous without a barrier. On the other hand, when the bottom layer of the bilayer graphene is replaced by a single hexagonal BN layer, the diamondized structure becomes nonmagnetic metal. The tunable electronic and magnetic properties pave new avenues to construct graphene-based electronics and spintronics devices.

  18. Thermal fluctuations of free standing graphene

    E-Print Network [OSTI]

    F. L. Braghin; N. Hasselmann

    2010-06-22

    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.

  19. Radiation stability of graphene under extreme conditions

    SciTech Connect (OSTI)

    Kumar, Sunil, E-mail: kumar.sunil092@gmail.com; Tripathi, Ambuj; Khan, Saif A.; Pannu, Compesh; Avasthi, Devesh K. [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2014-09-29

    In this letter, we report radiation stability of graphene under extreme condition of high energy density generated by 150?MeV Au ion irradiation. The experiment reveals that graphene is radiation resistant for irradiation at 10{sup 14?}ions/cm{sup 2} of 150?MeV Au ions. It is significant to note that annealing effects are observed at lower fluences whereas defect production occurs at higher fluences but significant crystallinity is retained. Our results demonstrate applicability of graphene based devices in radiation environment and space applications.

  20. Multi-plasmon absorption in graphene

    E-Print Network [OSTI]

    Marinko Jablan; Darrick E. Chang

    2015-01-21

    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.

  1. 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)

    2014-04-28

    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.

  2. Möbius Graphene Strip as Topological Insulator

    E-Print Network [OSTI]

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

    2009-06-12

    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.

  3. Self-weakening in lithiated graphene electrodes.

    SciTech Connect (OSTI)

    Yang, Hui [Pennsylvania State University; Huang, Xu [Pennsylvania State University; Liang, Wentao [Pennsylvania State University; Van Duin, Adri C. T. [Pennsylvania State University, University Park, PA; Raju, Muralikrishna [ORNL; Zhang, Sulin [Pennsylvania State University

    2013-01-01

    We present a molecular dynamics study of the fracture mechanisms of lithiated graphene. Our modeli ng results reveal that lithium diffusion toward the crack tip is both energetically and kinetically favored owing to the crack-tip stress gradient. The stress-driven lithium diffusion results in lithium aggregation around the crack tip, chemically weakening the crack-tip bond and at the same time causing stress relax ation. Our simulations show that the chemical weakening effect is the dominant factor, which manifests a self-weakening mechanism in lithiated graphene. The atomistic understanding of the degradation mech anism provides guidance for the lifetime extension in the design of graphene-based electrodes.

  4. Direct growth of graphene on Si(111)

    SciTech Connect (OSTI)

    Thanh Trung, Pham Joucken, Frédéric; Colomer, Jean-François; Robert, Sporken; Campos-Delgado, Jessica; Raskin, Jean-Pierre; Hackens, Benoît; Santos, Cristiane N.

    2014-06-14

    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.

  5. Collision-dominated nonlinear hydrodynamics in graphene

    E-Print Network [OSTI]

    Briscot, U; Gornyi, I V; Titov, M; Narozhny, B N; Mirlin, A D

    2015-01-01

    We present an effective hydrodynamic theory of electronic transport in graphene in the interaction-dominated regime. We derive the emergent hydrodynamic description from the microscopic Boltzmann kinetic equation taking into account dissipation due to Coulomb interaction and find the viscosity of Dirac fermions in graphene for arbitrary densities. The viscous terms have a dramatic effect on transport coefficients in clean samples at high temperatures. Within linear response, we show that viscosity manifests itself in the nonlocal conductivity as well as dispersion of hydrodynamic plasmons. Beyond linear response, we apply the derived nonlinear hydrodynamics to the problem of hot spot relaxation in graphene.

  6. 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)

    2014-01-13

    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.

  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)

    2014-03-10

    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. Bielectron vortices in gated graphene

    E-Print Network [OSTI]

    C. A. Downing; M. E. Portnoi

    2015-06-14

    We study the formation of bound two-particle states in gapless monolayer graphene in gated structures. We find that, even in the regime of massless Dirac fermions, coupling can occur at zero-energy for different or same charge quasiparticles. These bipartite states must have a non-zero internal angular momentum, meaning that they only exist as stationary vortices. We propose a new picture of the experimentally seen Fermi velocity renormalization as a manifestation of these pairs, suggest the possibility of a condensate of these novel quasiparticles.

  9. Graphene with geometrically induced vorticity

    E-Print Network [OSTI]

    Jiannis K. Pachos; Michael Stone; Kristan Temme

    2008-03-26

    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.

  10. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura|Bilayer Graphene Gets a Bandgap Print

  11. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura|Bilayer Graphene Gets a Bandgap PrintBilayer

  12. Bainbridge Island Data Dashboard | Department of Energy

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

    The data dashboard for Bainbridge Island, a partner in the U.S. Department of Energy's Better Buildings Neighborhood Program. Bainbridge Island Data Dashboard More Documents &...

  13. Issues in Scalable Island Multicast

    E-Print Network [OSTI]

    Chan, Shueng-Han Gary

    Systems The Scalable Island Multicast protocol integrates Internet Protocol multicast and overlay deliveryDeployment Issues in Scalable Island Multicast for Peer-to-Peer Streaming Xing Jin Oracle USA Ho an important Inter- net application. In a P2P-streaming system, co- operative peers organize into an overlay

  14. Reversible micromachining locator

    DOE Patents [OSTI]

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

    1999-08-31

    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.

  15. Enjebi Island dose assessment

    SciTech Connect (OSTI)

    Robison, W.L.; Conrado, C.L.; Phillips, W.A.

    1987-07-01

    We have updeated the radiological dose assessment for Enjebi Island at Enewetak Atoll using data derived from analysis of food crops grown on Enjebi. This is a much more precise assessment of potential doses to people resettling Enjebi Island than the 1980 assessment in which there were no data available from food crops on Enjebi. Details of the methods and data used to evaluate each exposure pathway are presented. The terrestrial food chain is the most significant potential exposure pathway and /sup 137/Cs is the radionuclide responsible for most of the estimated dose over the next 50 y. The doses are calculated assuming a resettlement date of 1990. The average wholebody maximum annual estimated dose equivalent derived using our diet model is 166 mremy;the effective dose equivalent is 169 mremy. The estimated 30-, 50-, and 70-y integral whole-body dose equivalents are 3.5 rem, 5.1 rem, and 6.2 rem, respectively. Bone-marrow dose equivalents are only slightly higher than the whole-body estimates in each case. The bone-surface cells (endosteal cells) receive the highest dose, but they are a less sensitive cell population and are less sensitive to fatal cancer induction than whole body and bone marrow. The effective dose equivalents for 30, 50, and 70 y are 3.6 rem, 5.3 rem, and 6.6 rem, respectively. 79 refs., 17 figs., 24 tabs

  16. Remedial Action Work Plan Amchitka Island Mud Pit Closures

    SciTech Connect (OSTI)

    DOE/NV

    2001-04-05

    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.

  17. Novel electronic structures of superlattice composed of graphene and silicene

    SciTech Connect (OSTI)

    Yu, S.; Li, X.D. [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); Wu, S.Q., E-mail: wsq@xmu.edu.cn [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); Wen, Y.H. [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); Zhou, S. [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhu, Z.Z., E-mail: zzhu@xmu.edu.cn [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005 (China)

    2014-02-01

    Highlights: • Graphene/silicene superlattices exhibit metallic electronic properties. • Dirac point of graphene is folded to the ?-point in the superlattice system. • Significant changes in the transport properties of the graphene layers are expected. • Small amount of charge transfer from the graphene to the silicene layers is found. - Abstract: Superlattice is a major force in providing man-made materials with unique properties. Here we report a study of the structural and electronic properties of a superlattice made with alternate stacking of graphene and hexagonal silicene. Three possible stacking models, i.e., the top-, bridge- and hollow-stacking, are considered. The top-stacking is found to be the most stable pattern. Although both the free-standing graphene and silicene are semi-metals, our results suggest that the graphene and silicene layers in the superlattice both exhibit metallic electronic properties due to a small amount of charge transfer from the graphene to the silicene layers. More importantly, the Dirac point of graphene is folded to the ?-point of the superlattice, instead of the K-point in the isolated graphene. Such a change in the Dirac point of graphene could lead to significant change in the transportation property of the graphene layer. Moreover, the band structure and the charge transfer indicate that the interaction between the stacking sheets in the graphene/silicene superlattice is more than just the van der Waals interaction.

  18. Direct transfer of graphene onto flexible substrates

    E-Print Network [OSTI]

    Araujo, Paulo Antonio Trinidade

    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 ...

  19. Schwinger pair creation in multilayer graphene

    E-Print Network [OSTI]

    M. A. Zubkov

    2012-04-05

    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.

  20. Charge, spin and pseudospin in graphene

    E-Print Network [OSTI]

    Abanin, Dmitry A

    2008-01-01

    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 ...

  1. Chemistry at the Dirac Point of Graphene

    E-Print Network [OSTI]

    Sarkar, Santanu

    2013-01-01

    of graphene (dienophile) with 2,3-dimethoxy-1,3- butadiene (with 2,3-Dimethoxy-1,3-Butadiene (DMBD) The use of graphiterich diene, 2,3-dimethoxy- 1,3-butadiene (DMBD). The optimum

  2. Mechanical Properties of Monolayer Graphene Oxide

    E-Print Network [OSTI]

    for high-temperature process- ing,22 in electrical energy storage systems,23,24 and as discussed in several on silicon carbide,9,10 chemical reduction of graphene oxide (G O) in colloidal suspension,11 13 and plasma

  3. Electrical Transport in Carbon Nanotubes and Graphene

    E-Print Network [OSTI]

    Liu, Gang

    2010-01-01

    VI. Fabrication of Grapheme p-n-p Junction with ContactlessTransport in Grapheme p-n-p Junction with Contactless Gatesto Graphene p-n-p Junction A remarkable electronic property

  4. 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 ...

  5. Mechanical Modulation of Hybrid Graphene Microfiber Structure

    E-Print Network [OSTI]

    Xu, Fei; Lu, Yan-qing

    2015-01-01

    Recently, the strain engineering of two-dimensional materials such as graphene has attracted considerable attention for its great potential in functional nanodevices. Here, we theoretically and experimentally investigate the strain manipulation of a graphene-integrated microfiber system for the first time. We analyze the influential factors of strain tuning, i.e., the geometrical parameters of the microfiber, the strain magnitude, and the probe-light wavelength. Moreover, we experimentally achieve in-line modulation as high as 30% with a moderate strain of ~5%, which is two orders of magnitude larger than previous results. The dynamic vibration response is also researched. The broadband, polarization-independent, cost-effective, strain-based modulator may find applications in low-speed modulation and strain sensing. Further, we believe that our platform may allow for all-in fiber engineering of graphene-analogue materials and provide new ideas for graphene-integrated flexible device design.

  6. CVD-Enabled Graphene Manufacture and Technology

    E-Print Network [OSTI]

    Hofmann, Stephan; Braeuninger-Weimer, Philipp; Weatherup, Robert S.

    2015-06-26

    deposition (CVD) has emerged as the most versatile and promising technique to develop graphene and 2D material films into industrial device materials and this Perspective outlines recent progress, trends, and emerging CVD processing pathways. A key focus...

  7. 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 ...

  8. Mid-Infrared Plasmonic Biosensing with Graphene

    E-Print Network [OSTI]

    Rodrigo, Daniel; Janner, Davide; Etezadi, Dordaneh; de Abajo, F Javier García; Pruneri, Valerio; Altug, Hatice

    2015-01-01

    Infrared spectroscopy is the technique of choice for chemical identification of biomolecules through their vibrational fingerprints. However, infrared light interacts poorly with nanometric size molecules. Here, we exploit the unique electro-optical properties of graphene to demonstrate a high-sensitivity tunable plasmonic biosensor for chemically-specific label-free detection of protein monolayers. The plasmon resonance of nanostructured graphene is dynamically tuned to selectively probe the protein at different frequencies and extract its complex refractive index. Additionally, the extreme spatial light confinement in graphene, up to two orders of magnitude higher than in metals, produces an unprecedentedly high overlap with nanometric biomolecules, enabling superior sensitivity in the detection of their refractive index and vibrational fingerprints. The combination of tunable spectral selectivity and enhanced sensitivity of graphene opens exciting prospects for biosensing.

  9. Graphene Nanobubble: A New Optical Nonlinear Material

    E-Print Network [OSTI]

    Bao, Qiaoliang; Xiang, Yuanjiang; Zhang, Kai; Li, Shaojuan; Jiang, Xiaofang; Xu, Qing-Hua; Loh, Kian Ping; Venkatesan, T

    2015-01-01

    Graphene is a rising star in nonlinear optics due to its saturable absorption and giant Kerr nonlinearity, these properties are useful in digital optics based on optical nonlinear devices. However, practical applications require large optical nonlinearities and these are inherently limited by the interaction length of atomically thin graphene. Here, we demonstrate optical bistability in a Fabry Perot cavity containing monolayer and bilayer graphene which have been restructured to form nanobubbles. We find that graphene nanobubble can act as a new type of optical nonlinear media due to its vertical side wall as well as added curvature, which enable strong non linear dispersive effects leading to a large optically induced phase change. Unlike thermally induced bistability, the all optical switching between two transmission states happens within a time scale of tens of nanoseconds. Nanobubble based optical devices with intrinsic optical nonlinearity help to overcome the optical path length limitation of atomical...

  10. On zero energy states in graphene

    E-Print Network [OSTI]

    C. -L. Ho; P. Roy

    2014-10-02

    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.

  11. Lattice quantum electrodynamics for graphene

    E-Print Network [OSTI]

    Alessandro Giuliani; Vieri Mastropietro; Marcello Porta

    2011-07-24

    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.

  12. Graphene, Lattice QFT and Symmetries

    E-Print Network [OSTI]

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

    2011-03-07

    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.

  13. Enhanced Casimir effect for doped graphene

    E-Print Network [OSTI]

    M. Bordag; I. Fialkovsky; D. Vassilevich

    2015-07-30

    We analyze the Casimir interaction of doped graphene. To this end we derive a simple expression for the finite temperature polarization tensor with a chemical potential. It is found that doping leads to a strong enhancement of the Casimir force reaching almost $60\\%$ in quite realistic situations. This result should be important for planning and interpreting the Casimir measurements, especially taking into account that the Casimir interaction of undoped graphene is rather weak.

  14. Titania-graphene anode electrode paper

    DOE Patents [OSTI]

    Liu, Jun; Choi, Daiwon; Bennett, Wendy D.; Graff, Gordon L.; Shin, Yongsoon

    2015-05-26

    A method for forming a nanocomposite material, the nanocomposite material formed thereby, and a battery made using the nanocomposite material. Metal oxide and graphene are placed in a solvent to form a suspension. The suspension is then applied to a current collector. The solvent is then evaporated to form a nanocomposite material. The nanocomposite material is then electrochemically cycled to form a nanocomposite material of at least one metal oxide in electrical communication with at least one graphene layer.

  15. Titania-graphene anode electrode paper

    DOE Patents [OSTI]

    Liu, Jun; Choi, Daiwon; Bennett, Wendy D; Graff, Gordon L; Shin, Yongsoon

    2013-10-15

    A method for forming a nanocomposite material, the nanocomposite material formed thereby, and a battery made using the nanocomposite material. Metal oxide and graphene are placed in a solvent to form a suspension. The suspension is then applied to a current collector. The solvent is then evaporated to form a nanocomposite material. The nanocomposite material is then electrochemically cycled to form a nanocomposite material of at least one metal oxide in electrical communication with at least one graphene layer.

  16. Enhanced Casimir effect for doped graphene

    E-Print Network [OSTI]

    Bordag, M; Vassilevich, D

    2015-01-01

    We analyze the Casimir interaction of doped graphene. To this end we derive a simple expression for the finite temperature polarization tensor with a chemical potential. It is found that doping leads to a strong enhancement of the Casimir force reaching almost $60\\%$ in quite realistic situations. This result should be important for planning and interpreting the Casimir measurements, especially taking into account that the Casimir interaction of undoped graphene is rather weak.

  17. 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 ...

  18. Growth morphology and properties of metals on graphene

    SciTech Connect (OSTI)

    Liu, Xiaojie; Han, Yong; Evans, James W.; Engstfeld, Albert K.; Behm, R. Juergen; Tringides, Michael C.; Hupalo, Myron; Lin, Hai-Qing; Huang, Li; Ho, Kai-Ming; Appy, David; Thiel, Patricia A.; Wang, Cai-Zhuang

    2015-12-01

    Graphene, a single atomic layer of graphite, has been the focus of recent intensive studies due to its novel electronic and structural properties. Metals grown on graphene also have been of interest because of their potential use as metal contacts in graphene devices, for spintronics applications, and for catalysis. All of these applications require good understanding and control of the metal growth morphology, which in part reflects the strength of the metal–graphene bond. The interaction between graphene and metal is sufficiently strong to modify the electronic structure of graphene is also of great importance. We will discuss recent experimental and computational studies related to deposition of metals on graphene supported on various substrates (SiC, SiO2, and hexagonal close-packed metal surfaces). Of specific interest are the metal–graphene interactions (adsorption energies and diffusion barriers of metal adatoms), and the crystal structures and thermal stability of the metal nanoclusters.

  19. Growth morphology and properties of metals on graphene

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Xiaojie; Han, Yong; Evans, James W.; Engstfeld, Albert K.; Behm, R. Juergen; Tringides, Michael C.; Hupalo, Myron; Lin, Hai -Qing; Huang, Li; Ho, Kai -Ming; et al

    2015-12-01

    Graphene, a single atomic layer of graphite, has been the focus of recent intensive studies due to its novel electronic and structural properties. With this study, metals grown on graphene also have been of interest because of their potential use as metal contacts in graphene devices, for spintronics applications, and for catalysis. All of these applications require good understanding and control of the metal growth morphology, which in part reflects the strength of the metal–graphene bond. The interaction between graphene and metal is sufficiently strong to modify the electronic structure of graphene is also of great importance. We will discussmore »recent experimental and computational studies related to deposition of metals on graphene supported on various substrates (SiC, SiO2, and hexagonal close-packed metal surfaces). Of specific interest are the metal–graphene interactions (adsorption energies and diffusion barriers of metal adatoms), and the crystal structures and thermal stability of the metal nanoclusters.« less

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

    E-Print Network [OSTI]

    Hofmann, Mario

    2012-01-01

    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 ...

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

    E-Print Network [OSTI]

    Au, Harold (Harold S.)

    2012-01-01

    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. 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 ...

  3. 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 ...

  4. Design, fabrication and characterisation of graphene electromechanical resonators 

    E-Print Network [OSTI]

    Chen, Tao

    2015-06-29

    In this thesis, the design, fabrication and characterisation of graphene electromechanical resonators have been presented. Graphene features ultrahigh Young’s modulus and large surface to volume ratio that make it ideal ...

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

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

    in a significant band gap, 0.26 electron volts (eV), an important step toward making graphene useful as a semiconductor. Left: In graphene's electronic band structure, the...

  6. Mechanical and Electrical Properties of Modified Graphene Devices

    E-Print Network [OSTI]

    ZHANG, HANG

    2012-01-01

    2D) is naturally compatible with standard CMOS-based technologies. However, since graphene is a gapless semiconductor,2D) is naturally compatible with standard CMOS-based technologies. However, as a gapless semiconductor, graphene

  7. Choosing a gate dielectric for graphene based transistors

    E-Print Network [OSTI]

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

    2008-01-01

    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. ...

  8. Hybrid Graphene Nematic Liquid Crystal Light Scattering Device

    E-Print Network [OSTI]

    Qasim, M. M.; Khan, A. A.; Kostanyan, A.; Kidambi, P. R.; Cabrero-Vilatela, A.; Braeuninger-Weimer, P.; Gardiner, D. J.; Hofman, S.; Wilkinson, T. D.

    2015-08-05

    A hybrid graphene nematic liquid crystal (LC) light scattering device is presented. This device exploits the inherent poly-crystallinity of chemical vapour deposited (CVD) graphene films to induce directional anchoring and formation of LC multi...

  9. 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...

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

  11. Graphene for radio frequency electronics and infrared thermal imaging

    E-Print Network [OSTI]

    Hsu, Allen Long

    2015-01-01

    The aim of this thesis is two-fold: The first is to develop a reliable processing technology for CVD graphene devices for applications in graphene circuits, i.e. mixers, frequency multipliers and phase key shifters. The ...

  12. 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 ...

  13. Extended Supersymmetry in Gapped and Superconducting Graphene

    E-Print Network [OSTI]

    V. K. Oikonomou

    2015-06-27

    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.

  14. Graphene: from materials science to particle physics

    E-Print Network [OSTI]

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

    2010-11-02

    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.

  15. Charge Transfer Properties Through Graphene Layers in Gas Detectors

    E-Print Network [OSTI]

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

    2015-01-01

    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.

  16. 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

    2015-03-23

    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.

  17. Role of substrate temperature at graphene synthesis in arc discharge

    E-Print Network [OSTI]

    Fang, Xiuqi; Keidar, Michael

    2015-01-01

    Substrate temperature required for synthesis of graphene in arc discharge plasma was studied. It was shown that increase of the copper substrate temperature up to melting point leads to increase in the amount of graphene production and quality of graphene sheets. Favorable range of substrate temperatures for arc-based graphene synthesis was determined in relatively narrow range of about 1340-1360K which is near the melting point of copper.

  18. 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)

    2013-07-15

    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.

  19. 3>2>1: Investigation of Single Particle Particle and Many Body Physics in Dual-Gated 1,2,3 Layers of Graphene

    E-Print Network [OSTI]

    Velasco, Jairo

    2012-01-01

    density, graphene behaves similar to a semiconductor within semiconductors before the appearance of graphene. A brief

  20. Two-fluid magnetic island dynamics in slab geometry: Determination of the island phase velocity

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    into helical magnetic islands. Such islands de- grade plasma confinement because heat and particles are ableTwo-fluid magnetic island dynamics in slab geometry: Determination of the island phase velocity R Phys. Plasmas 12, 122308 (2005); 10.1063/1.2141928 Two-fluid magnetic island dynamics in slab geometry

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    a renewed interest as a route towards high quality graphene prepared in a reproducible manner. Here weC) substrate has attracted much interest. Whatever the recent progress in the preparation of grapheneGrowth of graphene on Ir(111) Johann Coraux1 ,, Alpha T. N'Diaye1 §, Martin Engler1 , Carsten Busse

  7. 2006 Nature Publishing Group Graphene-based composite materials

    E-Print Network [OSTI]

    for the preparation of graphene-polymer composites via complete exfoliation of graphite9 and molecular© 2006 Nature Publishing Group Graphene-based composite materials Sasha Stankovich1 *, Dmitriy A. Piner1 , SonBinh T. Nguyen2 & Rodney S. Ruoff1 Graphene sheets--one-atom-thick two-dimensional layers

  8. Synthesis of Carbon Nanotubes by Rolling up Patterned Graphene

    E-Print Network [OSTI]

    Simons, Jack

    Synthesis of Carbon Nanotubes by Rolling up Patterned Graphene Nanoribbons Using Selective Atomic) are formed by folding graphene nanoribbons patterned on graphite films through adsorption of atoms of varying of SWNTs can be a priori controlled by patterning graphene nanoribbons with predefined width and direction

  9. Raman Enhancement on Graphene: Adsorbed and Intercalated Molecular

    E-Print Network [OSTI]

    Raman Enhancement on Graphene: Adsorbed and Intercalated Molecular Species Naeyoung Jung intercalation into bulk graphite shifts the Fermi level of individual graphene-like sheets by charge-transfer doping; this process has been studied for many decades.1 With single or few layer thick graphenes

  10. Boron nitride substrates for high-quality graphene electronics

    E-Print Network [OSTI]

    Shepard, Kenneth

    Boron nitride substrates for high-quality graphene electronics C. R. Dean1,2 *, A. F. Young3 , I and J. Hone2 * Graphene devices on standard SiO2 substrates are highly disor- dered, exhibiting characteristics that are far inferior to the expected intrinsic properties of graphene1­12 . Although suspend- ing

  11. Ultrathin Single-Walled Carbon Nanotube Network Framed Graphene Hybrids

    E-Print Network [OSTI]

    Wikswo, John

    Ultrathin Single-Walled Carbon Nanotube Network Framed Graphene Hybrids Rui Wang, Tu Hong, and Ya ABSTRACT: Graphene and single-walled carbon nanotubes (SWNTs) have shown superior potential in electronics method is developed to synthesize ultrathin SWNT-graphene films through chemical vapor deposition

  12. 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

  13. 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

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

    E-Print Network [OSTI]

    Fan, Shanhui

    and Development Labs, Nagakute, Aichi 480 1192, Japan 2 Department of Electrical Engineering, Stanford University of optics and electromagnetics, graphene1,2 has generated substantial interests due to a number of its graphene plas- mons can be routed between two different graphene wave- guides by relatively small chemical

  15. Strong and Electrically Conductive Graphene Based Composite Fibers and Laminates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vlassiouk, Ivan V.; Polyzos, Georgios; Cooper, Ryan C.; Ivanov, Ilia N.; Keum, Jong Kahk; Paulauskas, Felix L.; Datskos, Panos G.; Smirnov, Sergei

    2015-04-28

    Graphene is an ideal candidate for lightweight, high-strength composite materials given its superior mechanical properties (specific strength of 130 GPa and stiffness of 1 TPa). To date, easily scalable graphene-like materials in a form of separated flakes (exfoliated graphene, graphene oxide, and reduced graphene oxide) have been investigated as candidates for large-scale applications such as material reinforcement. These graphene-like materials do not fully exhibit all the capabilities of graphene in composite materials. In this study, we show that macro (2 inch × 2 inch) graphene laminates and fibers can be produced using large continuous sheets of single-layer graphene grown bymore »chemical vapor deposition. The resulting composite structures have potential to outperform the current state-of-the-art composite materials in both mechanical properties and electrical conductivities (>8 S/cm with only 0.13% volumetric graphene loading and 5 × 103 S/cm for pure graphene fibers) with estimated graphene contributions of >10 GPa in strength and 1 TPa in stiffness.« less

  16. Spatially-Resolved Structure and Electronic Properties of Graphene on

    E-Print Network [OSTI]

    Pohl, Karsten

    Spatially-Resolved Structure and Electronic Properties of Graphene on Polycrystalline Ni Jiebing method for producing large, continuous graphene films.1,2 One of the earliest approaches involves segregating carbon from the saturated bulk of a Ni thin film.3 The segregated carbon forms graphene

  17. Graphene and Nanowire Transistors for Cellular Interfaces and Electrical Recording

    E-Print Network [OSTI]

    Xie, Xiaoliang Sunney

    Graphene and Nanowire Transistors for Cellular Interfaces and Electrical Recording Tzahi Cohen interfaces with cell membranes. Graphene has also been shown to be an attractive building block for nanoscale the first studies of graphene field effect transistors (Gra-FETs) as well as combined Gra- and NW

  18. Direct observation of a widely tunable bandgap in bilayer graphene

    E-Print Network [OSTI]

    Zettl, Alex

    . Most notably, the inversion symmetric AB-stacked bilayer graphene is a zero-bandgap semiconductor in the graphene FET device we are able to control independently the two key semiconductor parameters: electronicLETTERS Direct observation of a widely tunable bandgap in bilayer graphene Yuanbo Zhang1 *, Tsung

  19. Schematic structure of nitrogen-doped graphene showing carbon

    E-Print Network [OSTI]

    Gong, Jian Ru

    method for graphene doping, and is compatible with current complementary metal oxide semiconductor (CMOSSchematic structure of nitrogen- doped graphene showing carbon (gray) and nitrogen (blue) NPG Asia Materials research highlight | doi:10.1038/asiamat.2010.204 Published online 13 December 2010 Graphene

  20. Energy Transfer from Individual Semiconductor Nanocrystals to Graphene

    E-Print Network [OSTI]

    Energy Transfer from Individual Semiconductor Nanocrystals to Graphene Zheyuan Chen,,§ Ste when a dipole is placed in the vicin- ity of a transparent insulating surface. Graphene,3 5 and practical interest. Indeed, single-layer graphene (SLG) possesses extremely high carrier mobility,6 while

  1. AN IMPROVED METHOD FOR TRANSFERRING GRAPHENE GROWN BY CHEMICAL VAPOR

    E-Print Network [OSTI]

    AN IMPROVED METHOD FOR TRANSFERRING GRAPHENE GROWN BY CHEMICAL VAPOR DEPOSITION YUJIE REN Key Laboratory of Semiconductor Materials and Applications Xiamen University, Xiamen 361005, P. R In this paper, we report an improved transfer of graphene by directly picking up the graphene with target

  2. Photochemical Reactivity of Graphene Haitao Liu, Sunmin Ryu,

    E-Print Network [OSTI]

    semiconductor. A recent study showed that photoge- nerated carriers in graphene first equilibrate amongPhotochemical Reactivity of Graphene Haitao Liu, Sunmin Ryu, Zheyuan Chen, Michael L. Steigerwald a photochemical reaction between graphene and benzoyl peroxide. The reaction introduces spatially localized

  3. Facile, Noncovalent Decoration of Graphene Oxide Sheets with Nanocrystals

    E-Print Network [OSTI]

    Chen, Junhong

    -metal [25] and graphene-semiconductor [26] hybrid structures; however, these methods typically involveFacile, Noncovalent Decoration of Graphene Oxide Sheets with Nanocrystals Ganhua Lu1 , Shun Mao1 Facile dry decoration of graphene oxide sheets with aerosol Ag nanocrystals synthesized from an arc

  4. Graphene synthesis by ion implantation Slaven Garaj1

    E-Print Network [OSTI]

    with established large-scale semiconductor technologies. Recently, scalable graphene growth methods, based, and it takes the graphene synthesis into the realm of large-scale semiconductor foundries. In the first stepPage 1 Graphene synthesis by ion implantation Slaven Garaj1 , William Hubbard2 , and J. A

  5. Tearing Graphene Sheets From Adhesive Substrates Produces Tapered Nanoribbons

    E-Print Network [OSTI]

    Reis, Pedro Miguel

    Thin films Tearing Graphene Sheets From Adhesive Substrates Produces Tapered Nanoribbons Dipanjan from adhesive substrates is reported, including the discovery of the formation of tapered graphene that the resulting nanoribbon geometry is controlled by both the graphene­substrate adhesion energy and by the number

  6. Atomistic modelling of CVD synthesis of carbon nanotubes and graphene

    E-Print Network [OSTI]

    Elliott, James

    Atomistic modelling of CVD synthesis of carbon nanotubes and graphene James A. Elliott,*a Yasushi nanotubes (CNTs) and graphene by catalytic chemical vapour deposition (CCVD) and plasma-enhanced CVD (PECVD nucleation of a graphene sheet from amorphous carbon on a nickel surface. Although many groups have modelled

  7. 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

  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 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

  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 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

  12. 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

  13. 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

  14. 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

  15. Graphene surface plasmons at the near-infrared optical regime

    E-Print Network [OSTI]

    Fan, Shanhui

    Graphene surface plasmons at the near-infrared optical regime Qiming Zhang1,2 *, Xiangping Li1. Graphene has been identified as an emerging horizon for a nanoscale photonic platform because the Fermi level of intrinsic graphene can be engineered to support surface plasmons (SPs). The current solid back

  16. Graphene-enabled Wireless Communication for Massive Multicore Architectures

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    Graphene-enabled Wireless Communication for Massive Multicore Architectures Sergi Abadal, Eduard graphene-based planar antennas, which can radiate signals at the Terahertz band while utilizing lower chip that discusses the utilization of graphene-enabled wireless communication for massive multicore processors

  17. 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.

  18. Location linked information

    E-Print Network [OSTI]

    Mankins, Matthew William David, 1975-

    2003-01-01

    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 ...

  19. Locating Heat Recovery Opportunities 

    E-Print Network [OSTI]

    Waterland, A. F.

    1981-01-01

    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...

  20. The Rise of Spintronics in CVD Graphene Graphene's potential for spin based electronics is well known. However, a crucial

    E-Print Network [OSTI]

    Yao, Shao Q

    The Rise of Spintronics in CVD Graphene Graphene's potential for spin based electronics is well of graphene based spintronics applications. Manipulating electron charge is central to conventional electronic, or spintronics. In contrast to charge based applications, spin based applications are expected to be not only

  1. No Company Is An Island 

    E-Print Network [OSTI]

    Maddox, A.

    1989-01-01

    No company is an island. Utilities and their industrial customers are discovering that collaboration can breed opportunity while isolation can lead to ruin. Inter company relationships have changed over recent years and HL&P and its customers...

  2. The macroecology of island floras

    E-Print Network [OSTI]

    Weigelt, Patrick

    2015-01-01

    Ecology, 58, 445-449. Cabral, J.S. , Weigelt, P. , Kissling,among their islands (?) (Cabral et al. 2014). My colleagues?-diversity of vascular plants (Cabral et al. 2014). In the

  3. Renormalization group aspects of graphene

    E-Print Network [OSTI]

    Maria A. H. Vozmediano

    2010-10-25

    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.

  4. Holographic Graphene in a Cavity

    E-Print Network [OSTI]

    Nick Evans; Peter A. R. Jones

    2014-07-11

    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.

  5. Wind resource assessment: San Nicolas Island, California

    SciTech Connect (OSTI)

    McKenna, E. [National Renewable Energy Lab., Golden, CO (United States); Olsen, T.L. [Timothy L. Olsen Consulting, (United States)

    1996-01-01

    San Nicolas Island (SNI) is the site of the Navy Range Instrumentation Test Site which relies on an isolated diesel-powered grid for its energy needs. The island is located in the Pacific Ocean 85 miles southwest of Los Angeles, California and 65 miles south of the Naval Air Weapons Station (NAWS), Point Mugu, California. SNI is situated on the continental shelf at latitude N33{degree}14` and longitude W119{degree}27`. It is approximately 9 miles long and 3.6 miles wide and encompasses an area of 13,370 acres of land owned by the Navy in fee title. Winds on San Nicolas are prevailingly northwest and are strong most of the year. The average wind speed is 7.2 m/s (14 knots) and seasonal variation is small. The windiest months, March through July, have wind speeds averaging 8.2 m/s (16 knots). The least windy months, August through February, have wind speeds averaging 6.2 m/s (12 knots).

  6. Local deformations and incommensurability of high quality epitaxial graphene on a weakly interacting transition metal

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the sample from the graphene preparation temperature to the mea- surement temperature. Although graphene-standing graphene. The structure of graphene and its variations are very sensitive to the preparation conditions. INTRODUCTION Graphene preparation at the surface of low-carbon solubility metals like Ir,1 Cu,2 or Pt3

  7. Approaching ballistic transport in suspended graphene Xu Du, Ivan Skachko, Anthony Barker, Eva Y. Andrei

    E-Print Network [OSTI]

    Andrei, Eva Y.

    Information Contents A. Graphene preparation B. Suspending the graphene device C. Measurements D. Impact of lead geometry A. Graphene preparation Graphene deposition is done using a method similar to the oneApproaching ballistic transport in suspended graphene Xu Du, Ivan Skachko, Anthony Barker, Eva Y

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

    E-Print Network [OSTI]

    Alfè, Dario

    2011-01-01

    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

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

    E-Print Network [OSTI]

    Constantine Yannouleas; Igor Romanovsky; Uzi Landman

    2015-02-16

    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.

  10. 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)

    2014-06-02

    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.

  11. 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)

    2014-06-09

    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.

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

    SciTech Connect (OSTI)

    Rissanou, Anastassia N.; Harmandaris, Vagelis

    2014-05-15

    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.

  13. Graphene Based Electrochemical Sensors and Biosensors: A Review

    SciTech Connect (OSTI)

    Shao, Yuyan; Wang, Jun; Wu, Hong; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2010-05-01

    Graphene, emerging as a true 2-dimensional material, has received increasing attention due to its unique physicochemical properties (high surface area, excellent conductivity, high mechanical strength, and ease of functionalization and mass production). This article selectively reviews recent advances in graphene-based electrochemical sensors and biosensors. In particular, graphene for direct electrochemistry of enzyme, its electrocatalytic activity toward small biomolecules (hydrogen peroxide, NADH, dopamine, etc.), and graphene-based enzyme biosensors have been summarized in more detail; Graphene-based DNA sensing and environmental analysis have been discussed. Future perspectives in this rapidly developing field are also discussed.

  14. Sustaining Sherman Island: A Water Management and Agricultural Diversification System

    E-Print Network [OSTI]

    Fischer, Richard

    2011-01-01

    system for Sherman Island and any Delta system must considera Saltwater Barrier System at Sherman Island. ” May 8. Deltagrown on Sherman Island with this system: artichokes,

  15. Weyl-Gauge Symmetry of Graphene

    E-Print Network [OSTI]

    Alfredo Iorio

    2011-01-19

    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.

  16. Graphene-based qubits in quantum communications

    E-Print Network [OSTI]

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

    2012-07-09

    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.

  17. Thermodynamic properties of a magnetically modulated graphene

    E-Print Network [OSTI]

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

    2011-09-12

    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.

  18. 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)

    2014-04-28

    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.

  19. Fabrication of a graphene-cuprous oxide composite

    SciTech Connect (OSTI)

    Xu Chao [Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education, Nanjing University of Science and Technology, Nanjing 210094 (China); Wang Xin, E-mail: wxin@public1.ptt.js.c [Key Laboratory for Soft Chemistry and Functional Materials of Ministry Education, Nanjing University of Science and Technology, Nanjing 210094 (China); Yang Lichun; Wu Yuping [Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (China)

    2009-09-15

    A composite of graphene-cuprous oxide (Cu{sub 2}O) was prepared using copper acetate-adsorbed graphene oxide (GO) sheets as precursors. In this composite, in-situ formed Cu{sub 2}O particles were derived from the adsorbed copper acetate which attached to graphene sheets and prevented the aggregation of the reduced graphene oxide sheets. The as-synthesized Cu{sub 2}O crystals were cube-like particles distributed randomly on the sheets due to the template effect of GO, consequently forming a graphene-Cu{sub 2}O cubes composite. A preliminary study on the electrochemical behavior of the graphene-Cu{sub 2}O composite used as anode material for lithium ion batteries was carried out. - Abstract: The graphene oxide sheets are reduced and almost exfoliated due to the in-situ formation of Cu{sub 2}O crystals deriving from the adsorbed copper acetate. Display Omitted

  20. Location logistics of industrial facilities 

    E-Print Network [OSTI]

    Hammack, William Eugene

    1981-01-01

    Maine Massachusetts New Hampshire Rhode Island Vermont South Atlantic SA Delaware D1strict of Columbia Florida Georgia Maryland North Carolina South Carol1na Virginia West Virginia Paci f1 c PAC Iowa Kansas Minnesota Missouri Nebraska...