Effect of Surface Roughness and Vacancies on the Scaling Behavior of Armchair Graphene Nanoribbons

Scaling behavior of armchair graphene nanoribbons in the presence of substrate induced surface roughness andvacancies is studied. The electronic characteristic of nanoribbons is investigated in terms of the on-, the off- and the on-/off-state conductance ratio. We use the concept of the transport-gap to reveal the physics behind the scaling response of thenanoribbons. Surface roughness is generated by means of two-dimensional Gaussian autocorrelation functions. An up tothird nearest neighbor tight-binding Hamiltonian and NEGF formalism are used to simulate atomistic quantum transport.Due to statistical nature of roughness and vacancies the electronic characteristics are averaged over a large ensemble ofgraphene nanoribbons. Results show that in the presence vacancy the transport gap is size dependent while it remainsconstant in the presence of surface roughness. We find that in the p

Keywords:

AGNRs , NEGF , Scaling behavior , SR , Vacancy