A Tight-Binding Hamiltonian for Band Structure and Carrier Transport in Graphene Nanoribbons

Abstract

ABSTRACTTo understand nanoribbons of graphene, we developed an ab initio parametrized fit to Carbon and Hydrogen chemical data, out to arbitrary neighbor interactions, including relaxations. Our computed band structure confirms the well-known three-family behavior of armchair bangaps but also predicts a similar familial behavior for conductance in nanoribbon transistors. The Boltzmann carrier transport simulations from calculated phonon spectra show, over a range of temperatures, the familial conductance behavior. Both the peak field-effect mobility and the "on" conductance increase with ribbon width, the later being proportional to the width and inversely proportional to the lattice temperature. We will also discuss phonon-limited scattering of charge carriers in graphene.