▎ 摘　　要

Direct growth of self-aligned spindle-shape graphene nanoribbons (GNRs) on SiC(11-20) substrate is demonstrated. It is found all the GNRs are monolayer and one of edges of each endpoint of GNR is along direction of zigzag-edge. The length directions of the GNRs are all coincided with the [0001] direction of SiC due to the anisotropy surface energy of SiC. Furthermore, the doping type of GNRs is p-type and its carrier density is changing with the variation of ribbon width. The size-dependent Fermi level variation in sub-micron scale GNR renders a P-P+P- potential configuration in a single GNR. The existed zigzag edges and a special potential configuration in a single GNR make it promise for fabrication of graphene based devices as triode and spintronic device. (C) 2016 Elsevier Ltd. All rights reserved.