Influence of Edge Defects, Vacancies, and Potential Fluctuations on Transport Properties of Extremely Scaled Graphene Nanoribbons

Atomistic quantum transport simulations of a large ensemble of devices are employed to investigate the impact of different sources of disorder on the transport properties of extremely scaled (length of 10 nm and width of 1-4 nm) graphene nanoribbons. We report the dependence of the transport gap, on- and off-state conductances, and on-off ratio on edge-defect density, vacancy density, and potential fluctuation amplitude. For the smallest devices and realistic lattice defect densities, the transport gap increases by up to ~300%, and the on-off ratio reaches almost ~10⁶ . We also report a rather high variation of the transport gap and on-off ratio. In contrast, we find that the potential fluctuations have a negligible impact on the transport gap and cause a relatively modest increase of the on-off ratio.