Transport properties and localization of electronic states in graphene nanoribbons with edge absorptions

Abstract

We study the effect of edge methylene on transport properties in graphene nanoribbons (GNRs) using the recursive green's function method. The concentration of methylene (w) is defined as the substituted probability of edge dangling bonds. Due to the antiresonance of quasilocalized states, some conductance dips are found when single absorption (w = 0.005 in this work) sits on the edge. Localization analyses of wave functions also confirm this. With w increasing, the conductance is suppressed significantly and transport gap develops near E = 0.0 eV. Conductance suppression is induced by antiresonances between edge scattering centers. Meanwhile, these scattering centers prevent the formation of edge extended states which play an important role in the electronic transport at low energy and consequently the transport gaps develop. We found that a stable gap can be obtained at w = 0.3 and it becomes small as the width of the GNRs increases. An interesting oscillation at transport gaps for armchair edge GNRs is observed and it relates to the geometric symmetry of sample. The physical mechanisms behind the novel phenomenon are still unclear.

Efficient interfacial interaction for improving mechanical properties of polydimethylsiloxane nanocomposites filled with low content of graphene oxide nanoribbons

“…Carbon nanollers including carbon nanotubes (CNTs), graphite, graphene sheets and their derivatives have recently received considerable interest for improving the mechanical and functional properties of various polymers due to their unique structure and intriguing physical performance. [12][13][14][15][16][17][18][19][20][21][22][23] Among these carbon nanollers, graphene nanoribbons (GNRs) integrate the structures and properties of 1D CNTs and 2D graphene sheets, 24,25 and exhibit excellent chemical/physical properties. [26][27][28] Especially, graphene oxide nanoribbons (GONRs) are narrow strips of graphene oxide (GO) sheets with high length-towidth ratio (usually more than 10, similar to CNT) and high specic surface area ($511 m 2 g À1 ), 29 which can be fabricated by longitudinal unzipping CNTs or chemical vapor deposition method.…”