We make use of firstprinciples calculations, based on the density functional theory dft, to investigate the alterations at the structural, energetic, electronic and magnetic properties of graphene and zigzag graphene nanoribbons zgnrs due to the inclusion of. Graphene has excellent electronic, mechanicaland thermal properties. Electronic structure of graphene in kvalley berry phase. The structural and electronic characteristics of fluorinated graphene are investigated based on first. Graphene, a twodimensional crystal with carbon c atoms packed in a hexagonal lattice, has attracted extensive research attention in the past decade, owing to its extraordinary properties 1,2,3,4. Graphene has a special set of properties which set it apart from other allotropes of carbon. The unusual electronic properties of graphene, a twodimensional 2d material comprised of hexagonallybonded carbon atoms, have excited. Electronic properties of graphene school of physics. Edge surface states in graphene are strongly dependent on the edge termination zigzag or armchair and a ect the physical properties of nanoribbons. Graphene is a zerogap semiconductor, because its conduction and valence bands meet at the dirac points, which are six locations in momentum space, on the.
Electric properties of molecules, continued there are 3 methods of computing the dipole moment and other rstorder properties like, e. Inspired by the experimentally observed zigzagarmchair graphene nanoribbon heterojunctions, we constructed a new class of infinitely long hybrid graphene nanoribbons hgnrs, and systematically investigated their electronic and magnetic properties by means of spinpolarized firstprinciples computations. In the case of graphene, however, the interaction between electrons and the honeycomb lattice causes the electrons to behave as if they have absolutely no mass. Exploring optical and electrical properties of 2d materials. Macroscopic 3d nanographene with dynamically tunable bulk.
The electronic properties were assessed via hall effect measurement hms3000 and microcurrent 4200, keithley, cleveland, oh, usa measurements. Graphene nanoribbons gnrs are expected to display extraordinary properties in the form of nanostructures. Contents 1 introduction 2 2 synthesis and structure of carbon nanotubes 2 3 electronic properties of carbon nanotubes 4 4 electrical transport in singlewall carbon nanotubes 9. Tuning the electronic and optical properties of graphene. Edge surface states in graphene are strongly dependent on the edge termination zigzag or armchair and affect the physical properties of nanoribbons. Many propositions have been already put forth for the practical use of n graphene in various devices, such as batteries, sensors, ultracapacitors, and next generation electronics. The chemistry of imperfections in ngraphene nano letters. Structural and electronic properties of epitaxial graphene. Graphenes excellent electronic, optical and mechanical properties make it an. We investigate the electronic properties of graphene nanoflakes on ag111 and au111 surfaces by means of scanning tunneling microscopy and spectroscopy as. Change of the phase of the wavefunction when the electronic wavefunction is rotated around the dirac point chirality momentum pseudo spin helicity projection of its spin onto the direction of propagation valley pseudospin band index is determined by chirality and valley pseudospin. Graphene was first exfoliated mechanically from graphite in 2004 9. This book covers a variety of topics related to the electronic and quantum transport properties of graphenebased nanomaterials.
Graphenebased nanomaterials introduction to graphene. With the location of various nitrogen species uniquely identified, we observe that for the same doping procedure, the graphene support. Graphene a new form of carbon with scientific impact and. The optical properties of graphene quantum dots gqds can be modified through introducing heteroatoms, including doping heteroatoms and covalent bonding with specific groups.
However, the chemistry of nitrogen imperfections in this material still remains an enigma. Electronic properties of graphene i vladimir falko helped by v. The unusual electronic properties of graphene, a twodimensional 2d material comprised of hexagonallybonded carbon atoms, have excited the physics community since its discovery more than a decade ago. For the graphene it is found that the inclusion of defects breaks the translational. The si100h surface does not perturb graphene s electronic properties, whereas the interaction between it and the clean si100 surface changes its electronic states significantly. Modifying the electrical properties of graphene by reversible point. Investigation of electronic properties of graphenesi. Comment on modification of graphene properties due to electronbeam irradiation pdf version also available for download. Comment on modification of graphene properties due to. Companies tend to file first in their home jurisdiction. We study, within the tightbinding approximation, the electronic properties of a graphene bilayer in the presence of an external electric field applied perpendicular to the systema biased bilayer. This effect results from the covalent bonding between c and surface. Synthesis of graphene oxide go by modified hummers. Bassam alfeeli visiting scientists, mit research scientist, kuwait institute for scientific research faculty host at mit prof.
Strain engineering of graphenes electronic structure. Filled and empty electronic states were probed by soft. Structural and electronic properties of nitrogendoped. Ng was studied to provide the basis to understand how interfacial phenomena affect the bulk properties of the material. These articles discuss the modification of graphene properties due to electronbeam irradiation. Structural and electronic properties of nitrogendoped graphene. Michael strano strano research group department of chemical engineering. Properties of graphene more about electronic properties hall effect extraordinary properties, extraordinary applications summary 5. Graphene a new form of carbon with scientific impact and technological promise a graphic of the electron behaviour of graphene in a magnetic field as mapped with an electron microscope a visual representation of the unusual energymomentum relationship of the charge carriers in graphene, which gives rise to its unusual quantum behaviour. The hybrid fibers exhibited significantly improved nh3 sensing response. In the past year, this grant has supported a graduate student who has been working on the theory of graphene and the quantum spin hall effect. We discuss the electronic properties of graphene stacks and show that they vary with stacking order and number of layers.
We used an efficient selfassembly method in which nanotubes were functionalized with cationic polyelectrolytes in order to make them dispersible in water, and subsequently. Welcome to the website of romain danneaus research group focused on the electronic properties of graphene, one of the topics researched in carbonbased nanostructures at the institute of nanotechnology int at the karlsruhe institute of technology. Aug 23, 2016 the electronic properties of the bilayer structures listed above are rather different. Stacking can change the electronic properties considerably and the layering structure can be used in order to control the electronic properties. Pdf the electronic properties of graphene researchgate. Many propositions have been already put forth for the practical use of ngraphene in various devices, such as batteries, sensors, ultracapacitors, and next generation electronics. We have found that the oxygen atom prefers to adsorb at the center of the cc bond, and the interaction between the oxygen atom and penta graphene is a strong chemical bond. To this end, ndoped epitaxial monolayer graphene emlg and hintercalated quasifreestanding monolayer graphene qfmlg, both grown on 6hsic.
Density functional theory calculations have been performed on graphene nano ribbons gnrs to investigate the electronic properties as a function of chirality, size and hydrogenation on the edges. The electrical properties, especially the carrier transport behavior in graphene, are highly relevant to the scattering mechanism at lattice defects, ripples and ionized impurities 5,16. Tunable electronic properties of graphene through controlling. D 2010 structural and electronic properties of epitaxial graphene on sic0001. This article gives comment to a previous article entitled modification of graphene properties due to. The electronic properties of graphene are significantly influenced by the supporting substrate. Electronic properties topics to be discussed introduction to graphene why graphene is so special.
Strain engineering of graphenes electronic structure vitor m. The deliberate incorporation of heteroatoms into the graphene lattice could offer an efficient way to tailor its electronic 5, chemical 6, optical 7 and magnetic 8 properties, and therefore. Using this approach, we have probed the local electronic properties of graphene. These experiments establish graphene as the strongest material ever measured. The electronic properties of graphene ucsb physics. The calculations were performed on gnrs with armchair and zigzag configurations with 28, 34, 36, 40, 50, 56, 62, 66 carbon atoms. Graphene is the strongest, thinnest material known to exist. Hence, we use density functional theory dft and timedependent td dft to understand the effects of boron doping configurations i.
The unique electronic properties of graphene boston university. The electronic properties of graphene stacks are discussed and vary with stacking order and number of layers. Jul 24, 2015 a key enabling step in these first contactfree measurements of the electronic properties of graphene was the realisation that the graphene conductance could be tuned during the measurements using. This simple, lowbudget technique has been widely credited for the explosive growth of interest in graphene. The theories of electronic properties of the bilayer systems are built upon the knowledge of.
Structural and electronic properties of graphene nanoflakes. These measurements involve applying large electric fields to molecules in films or matrices and analyzing the effects of the field perturbation on the absorption or emission spectrum. When the oxygen coverage increases, the band gap of penta graphene gradually widens. The incredible physical properties of graphene practically beg to be applied in all sorts of thought experiments. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Figure 1 schematic illustration of the graphenesi fieldeffect transistor. The results show that atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime. Investigation of electronic properties of graphenesi field. Electronic properties of graphenebased bilayer systems. The present thesis is dedicated to the study of graphene. Roomtemperature, highly durable ti3c2tx mxenegraphene.
We used an efficient selfassembly method in which nanotubes were functionalized with cationic polyelectrolytes in order to make them dispersible in water, and. We elucidate the atomic and electronic structure of graphene oxide go using annular dark. It introduces, informs and tells the past, present and future of graphene. Researchers control the properties of graphene transistors. We report the preparation of hybrid paperlike films consisting of alternating layers of graphene or graphene oxide and different types of multiwalled carbon nanotubes ndoped mwnts, bdoped mwnts, and pristine mwnts. A key enabling step in these first contactfree measurements of the electronic properties of graphene was the realisation that the graphene conductance could be. Structural and electronic properties of epitaxial graphene on. Castro neto department of physics, boston university, 590 commonwealth avenue, boston, massachusetts 02215, usa received february 2009. Science and technology roadmap for graphene, related. It has a youngs modulus of 1 and intrinsic tpa strength of gpa. Researchers control properties of graphene transistors. Graphene flakes have been invaluable to the study and elucidation of graphene properties. Exploring optical and electrical properties of 2d materials by photoconductive atomic force microscopy for photovoltaic applications dr. This property is the same as that of light and is compatible with massless particles.
Large area films of alternating graphenecarbon nanotube. Structural and electronic properties of fluorographene. From the point of view of its electronic properties, graphene is a twodimensional zerogap semiconductor and its lowenergy quasiparticles formally described by the diraclike hamiltonian hiv f. Apr 25, 20 graphene nanoribbons gnrs are expected to display extraordinary properties in the form of nanostructures. The electronic hamiltonian describing the low energy electronic structure of graphene can then be written in the form of a relativistic dirac hamiltonian. We also discuss how di erent types of disorder modify the dirac equation leading to. Electronic and magnetic properties of hybrid graphene. Wallace in 1947 as a starting point for understanding the electronic properties of 3d graphite. This results in the observation of a number of very peculiar electronic properties from an. These unique electronic properties controlled by design, makes mollecular pillared graphene an excellent material for flexible electronics.
Singlelayer and monocomponent doped graphene is a crucial platform for a better understanding of the relationship between its intrinsic electronic. The unusual electronic properties of graphene 2 are stimulating the research in graphene based fets. Introduction to graphenebased nanomaterials is a new book published by cambridge university press. It has been observed that the electronic structures of the doped. A detailed analysis of the energy order for stoichiometric. Mar 22, 2016 we investigate the electronic properties of graphene nanoflakes on ag111 and au111 surfaces by means of scanning tunneling microscopy and spectroscopy as well as density functional theory. Jun 21, 2016 singlelayer and monocomponent doped graphene is a crucial platform for a better understanding of the relationship between its intrinsic electronic properties and atomic bonding configurations. The local information provided by scanning probe microscopy is invaluable for studying effects such as interactions and scattering. We make use of firstprinciples calculations, based on the density functional theory dft, to investigate the alterations at the structural, energetic, electronic and magnetic properties of graphene and zigzag graphene nanoribbons zgnrs due to the inclusion of different types of line and punctual defects. Edge surface states in graphene depend on the edge termination zigzag or armchair and affect the physical properties of nanoribbons.
However, the most established technique to obtain high quality graphene sheets, i. The effect of boron and nitrogen substitutional doping at four successive positions on electronic and transport properties of zigzag graphene nanoribbons zgnrs is studied using spinunpolarized density functional theory. It has a very high electronic conductivity at room temperature. Hgnrs are converted from nonmagnetic semiconductors to magnetic semiconductors by.669 1510 712 1180 706 894 1400 275 259 129 1400 973 73 159 861 1048 743 487 57 1173 231 624 1072 166 709 320 158 709 1298 1242 262 993 39 1111 227 1043 1197 1395 1129 16 1137 1478 712 742 1136 1154 427 997 384