▎ 摘　　要

Using nonequilibrium Green's functions in combination with the density functional theory, we investigate the spin-dependent electronic transport properties of two nanostructure devices based on graphitic carbon nitrides bridging two zigzag graphene nanoribbons, i.e., center and edge bridged devices, respectively. It is found that the center bridged device behaves spin negative differential resistance properties in different bias ranges for the up and down spin current respectively. The edge bridged device presents obvious negative differential resistance only for the down spin current. Moreover, high spin-filtering efficiency over 80% is obtained in the edge bridged device in the bias range of 0-1.0 V. The magnetic properties of these devices suggest promising applications in spintronics and molecular electronics. (C) 2014 Elsevier B.V. All rights reserved.