Transport in disordered graphene nanoribbons

Abstract

We study electronic transport in graphene nanoribbons with rough edges. We first consider a model of weak disorder that corresponds to an armchair ribbon whose width randomly changes by a single unit cell size. We find that in this case, the low-temperature conductivity is governed by an effective one-dimensional hopping between segments of distinct band structure. We then provide numerical evidence and qualitative arguments that similar behavior also occurs in the limit of strong uncorrelated boundary disorder.

Charge transport in disordered graphene-based low dimensional materials

“…The basic idea is to start from a tight-binding Hamiltonian for a clean and regular ribbon (in general with hydrogen passivation on the edges), and then adding [37] or removing [36, 139 141] carbon atoms at the edges, or varying the width of the system [142] to account for roughness, or introducing Anderson disorder [143]. The most proper way of adding/removing atoms at the edges avoids fi nal confi gurations that might cause steric problems.…”

“…The effect of sequences of large conducting and semiconductor armchair fragments has been investigated in detail by Martin et al [142]. The length of each metallic fragment is such as to preserve the band structure of the corresponding Nano Res (2008) 1: 361 394 Nano Research least for wide ribbons.…”

Suppression of thermal conductivity in graphene nanoribbons with rough edges

“…[6][7][8]). It was found that already very modest edge disorder is sufficient to induce the conduction energy gap in the otherwise metallic nanoribbons and to lift any difference in the conductance between nanoribbons of different edge geometry, suggesting that this type of disorder can be very important for altering other fundamental characteristics of GHRs.…”

Edge scattering of electrons in graphene: Boltzmann equation approach to the transport in graphene nanoribbons and nanodisks

“…[25][26][27][28][29][30] In particular, such calculations confirmed the essential contribution to conductivity from the edge states provided that the intervalley coupling due to scattering from impurities is absent. [25][26][27] Besides, the localization corrections to the conductivity in disordered graphene nanoribbons have been studied by Lherbier et al 28 and Mucciolo et al 29 They found that the edges essentially affect the disorder-induced corrections.…”

“…The role of randomly fluctuating width of the nanoribbon has been also studied numerically by Martin and Blanter. 30 In their model, the low-temperature conductivity can be governed by electron hoppings between some segments of the ribbon.…”