▎ 摘　　要

We investigate the transport properties of ultranarrow zigzag graphene nanoribbons (ZGNRs) with edge vacancies by using recursive Green's function method. Transport gaps are observed when the vacancies are distributed uniformly on both sides. In addition, ZGNRs with symmetrical structure have much larger transport gaps than the asymmetrical ones. This phenomenon results from the different band structures between them. We also calculate the conductance of ZGNRs with edge vacancies distributed randomly. It shows that transport gaps decrease exponentially with the increasing of ZGNRs width because the symmetry of structure is broken by the random edge vacancies. Localization analysis reveals that the electronic transport channels around Fermi energy are blockaded so that they are not responsible for electron transmission. (C) 2016 Elsevier B.V. All rights reserved.