▎ 摘　　要

We investigate the effect of single lattice vacancies on the electron transport of graphene nanoribbon devices using the Landauer formalism within a tight binding approach. For a zigzag nanoribbon, a single lattice vacancy creates conductance dips in the low energy region, due to quasi bound states around the vacancy site. The energy of the bound state is related to the position of the lattice vacancy relative to the edge of the ribbon. We carried out calculations of electron transport properties in a T-junction device with lattice vacancies. We find that the effect of the vacancies depends on how energetically favorable the lattice vacancy is, which can be studied in terms of the alternate atomic structure of the graphene lattice. (C) 2007 Wiley Periodicals, Inc.