Electrical transport of zig-zag and folded graphene nanoribbons

2013 ◽  
Vol 1549 ◽  
pp. 41-46
Author(s):  
Watheq Elias ◽  
M. Elliott ◽  
C. C. Matthai
Keyword(s):  
Molecular Electronics ◽  
Electrical Transport ◽  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Electronic Structure Calculations ◽  
Binding Model ◽  
Aromatic Molecules ◽  
Greens Function ◽  
Extended Hückel Approximation ◽  
Structure Calculations

ABSTRACTIn recent years, there has been much interest in modelling graphene nanoribbons as they have great potential for use in molecular electronics. We have employed the NEGF formalism to determine the conductivity of graphene nanoribbons in various configurations. The electronic structure calculations were performed within the framework of the Extended Huckel Approximation. Both zigzag and armchair nanoribbons have been considered. In addition, we have also computed the transmission and conductance using the non-equilibrium Greens function formalism for these structures. We also investigated the effect of defects by considering a zigzag nanoribbon with six carbon atoms removed. Finally, the effect of embedding boron nitride aromatic molecules in the nanoribbon has been considered. The results of our calculations are compared with that obtained from recent work carried out using tight-binding model Hamiltonians.

ZERO AND FINITE TEMPERATURE STUDY OF SINGLE FULLERENE CAGES AND CARBON “ONIONS” — GEOMETRY AND SHAPE

1993 ◽  
Vol 07 (29n30) ◽  
pp. 1883-1895 ◽  
Author(s):  
A. MAITI ◽  
C.J. BRABEC ◽  
J. BERNHOLC
Keyword(s):  
Interatomic Potential ◽  
Critical Size ◽  
Tight Binding ◽  
Configurational Entropy ◽  
Electronic Structure Calculations ◽  
Carbon Onions ◽  
Three Body ◽  
Structure Calculations ◽  
Scaling Arguments

Scaling arguments are used to show that above a critical size of several thousand atoms, there is a stability crossover from single to multilayer cages. Conjugate gradient minimization using a classical three-body interatomic potential, as well as tight-binding electronic structure calculations yield ground-state configurations for large fullerene shells that are polyhedral with clearly faceted geometry. The structure, energetics and configurational entropy associated with low-energy defects are calculated and the number of defects estimated as a function of temperature. The role of these thermally generated defects on the shape of large fullerenes is investigated in order to explain the nearly spherical shapes of the newly discovered carbon “onions”.

scholarly journals Accurate six-band nearest-neighbor tight-binding model for the π-bands of bulk graphene and graphene nanoribbons

2011 ◽  
Vol 109 (10) ◽  
pp. 104304 ◽  
Author(s):  
Timothy B. Boykin ◽  
Mathieu Luisier ◽  
Gerhard Klimeck ◽  
Xueping Jiang ◽  
Neerav Kharche ◽  
...  
Keyword(s):  
Nearest Neighbor ◽  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Tight Binding Model ◽  
Binding Model

scholarly journals Intrinsic Spin-Orbit Coupling in Zigzag and Armchair Graphene Nanoribbons

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Ying Li ◽  
Erhu Zhang ◽  
Baihua Gong ◽  
Shengli Zhang
Keyword(s):  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Geometrical Parameters ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Binding Model ◽  
Tight Binding Approximation ◽  
Energy Gaps ◽  
Armchair Graphene Nanoribbons ◽  
Armchair Graphene

Starting from a tight-binding model, we derive the energy gaps induced by intrinsic spin-orbit (ISO) coupling in the low-energy band structures of graphene nanoribbons. The armchair graphene nanoribbons may be either semiconducting or metallic, depending on their widths in the absence of ISO interactions. For the metallic ones, the gaps induced by ISO coupling decrease with increasing ribbon widths. For the ISO interactions, we find that zigzag graphene nanoribbons with odd chains still have no band gaps while those with even chains have gaps with a monotonic decreasing dependence on the widths. First-principles calculations have also been carried out, verifying the results of the tight-binding approximation. Our paper reveals that the ISO interaction of graphene nanoribbons is governed by their geometrical parameters.

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