Electronic transport signatures of common defects in irradiated graphene-based systems

Ion irradiation of a graphene sheet can give rise to a wide range of point and extended defects on the ideal honeycomb lattice. Here we perform first-principles calculations for the determination of the electronic and transport properties of damaged graphene nanoribbons based on nonequilibrium Green function techniques. Considering a wide range of defects (vacancies, di-vacancies, Stone-Wales, sp(3)-type) we study the conductive characteristics, showing that the common feature in all cases is the presence of transport gaps induced by local perturbations of the wavefunction around the defected areas. However, the resonances of these pseudogaps are intrinsically related to the defect type, making possible a structural characterization of a defected graphene system based on its electrical behavior. (C) 2011 Elsevier B.V. All rights reserved.