Loading...
Search for:
tight-binding--tb
0.004 seconds
Tight-binding description of patterned graphene
, Article Semiconductor Science and Technology ; Volume 23, Issue 7 , 2008 ; 02681242 (ISSN) ; Alavi, M ; Khorasani, S ; Sharif University of Technology
2008
Abstract
The existence of an energy gap of graphene is vital as far as nano-electronic applications such as nano-transistors are concerned. In this paper, we present a method for introducing arbitrary energy gaps through breaking the symmetry point group of graphene. We investigate the tight-binding approximation for the dispersion of π and π* electronic bands in patterned graphene including up to five nearest neighbors. As we show by applying special defects in graphene structure, an energy gap appears at Dirac points and the effective mass of fermions also becomes a function of the number of defects per unit cell. © 2008 IOP Publishing Ltd
Modeling of a vertical tunneling transistor based on graphene-mos2 heterostructure
, Article IEEE Transactions on Electron Devices ; Volume 64, Issue 8 , 2017 , Pages 3459-3465 ; 00189383 (ISSN) ; Faez, R ; Pourfath, M ; Darvish, G ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
In this paper, for the first time, we present a computational study on the electrical behavior of the field-effect tunneling transistor based on vertical graphene-MoS2 heterostructure and vertical graphene nanoribbon-MoS2 heterostructure. Our simulation is based on nonequilibrium Green's function formalism along with an atomistic tight-binding (TB) model. The TB parameters are obtained by fitting the bandstructure to first-principle results. By using this model, electrical characteristics of device, such as I ON/I OFF ratio, subthreshold swing, and intrinsic gate-delay time, are investigated. We show that the combination of tunneling and thermionic transport allows modulation of current by...
Local impact of Stone–Wales defect on a single layer GNRFET
, Article Physics Letters, Section A: General, Atomic and Solid State Physics ; Volume 384, Issue 7 , 2020 ; Nazari, A ; Faez, R ; Shahhoseini, A ; Sharif University of Technology
Elsevier B.V
2020
Abstract
In this work, a new structure of single layer armchair graphene nanoribbon field effect transistor with the Stone–Wales (SW) defect (SWGNRFET) is studied. The simulations are solved with Poisson–Schrödinger equation self-consistently by using Non-Equilibrium Green Function (NEGF) and in the real space approach. The energy band structure is obtained by approximation tight-binding method. The results show that displacement of a defect in the width of the channel of the new structure is led to 50% increase in ION/IOFF ratio only by rotating of a C–C (Carbon–Carbon) bond with similar behavior. But, a remarkable increase of 300% in ION/IOFF ratio is obtained by a “dual center” defect. The results...