▎ 摘　　要

Electronic transport properties of zigzag graphene nanoribbons (GNRs) with two kinds of triangular defects are explored by using an ab-initio method. At a certain bias, the current of the GNR with an upward-triangle defect can be surprisingly larger than that of the perfect GNR due to the defect-induced symmetry breaking and more conductive channels. Dissimilarly, if the orientation of the triangle is changed rightward, the current is depressed much and shows negative differential resistance behavior. Our findings indicate that defect designs can be an efficient way to tune the electronic transport of GNR nanodevices. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3660228]