La Magna and Deretzis Nanoscale Research Letters 2011, 6:234 NANO EXPRESS Open Access Theoretical study of the role of metallic contacts in probing transport features of pure and defected graphene nanoribbons Antonino La Magna*, Ioannis Deretzis Abstract Understanding the roles of disorder and metal/graphene interface on the electronic and transport properties of graphene-based systems is crucial for a consistent analysis of the data deriving from experimental measurements. The present work is devoted to the detailed study of graphene nanoribbon systems by means of self-consistent quantum transport calculations. The computational formalism is based on a coupled Schrödinger/Poisson approach that respects both chemistry and electrostatics, applied. | La Magna and Deretzis Nanoscale Research Letters 2011 6 234 http content 6 1 234 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Theoretical study of the role of metallic contacts in probing transport features of pure and defected graphene nanoribbons Antonino La Magna loannis Deretzis Abstract Understanding the roles of disorder and metal graphene interface on the electronic and transport properties of graphene-based systems is crucial for a consistent analysis of the data deriving from experimental measurements. The present work is devoted to the detailed study of graphene nanoribbon systems by means of self-consistent quantum transport calculations. The computational formalism is based on a coupled Schrodinger Poisson approach that respects both chemistry and electrostatics applied to pure defected graphene nanoribbons ideally or end-contacted by various fcc metals . We theoretically characterize the formation of metal-graphene junctions as well as the effects of backscattering due to the presence of vacancies and impurities. Our results evidence that disorder can infer significant alterations on the conduction process giving rise to mobility gaps in the conductance distribution. Moreover we show the importance of metal-graphene coupling that gives rise to doping-related phenomena and a degradation of conductance quantization characteristics. Introduction Graphene nanoribbons GNRs are the most promising graphene-based nanostructures for electronic applications since they are potentially suited for band-gap engineering maintaining the excellent electronic properties of the parent two-dimensional graphene layer. GNRs have been already synthesized by means of different pattering techniques 1 2 and there exists convincing evidence that their electronic structure manifests subband formation which is a typical predicted signature of the one-dimensional 1D confinement 3 . Actually a useful intrinsic . due to the
