▎ 摘　　要

We study transport properties of two L-shaped graphene nanoribbons (LGNRs) with different corner deformation. It is found that the corner geometry of the L-shaped junction has enormous influence on the electron transport around the Fermi energy. As a triangle graphene flake is added to the inside corner of a metallic right-angle LGNR, a gap appears in the conductance, i.e., the properties of the LGNR transform from metallic to semiconducting. However, as a triangle graphene flake is cut from the deformed semiconducting LGNR, resonant peaks via quasi-bound states exist in the original gap of conductance. The LGNR with deformed inside and outside corners is equivalent to a resonant-tunneling transistor. The quasi-bound states inducing the resonant transmission are confined in the L-shaped junction and strongly dependent on the size of the corner. Thus one can tune the transport properties of LGNR by the structural geometry and size. (C) 2009 Elsevier B.V. All rights reserved.