▎ 摘　　要

We investigate the effect of changed BN nanoribbon on the rectifying behavior in zigzag graphene/BN nanoribbon heterojunction using first principles based on non-equilibrium Green's function and density functional theory. The increased BN length in the scattering region reduces the rectifying performance of the device, and the maximum rectifying ratio is 9.8 x 10(14) in the heterojunction. We discuss the different rectifying characteristics for the designed models by calculating the transmission spectra at different biases. The rectifying phenomenon is further investigated by the projected density of state of device. Furthermore, we explain the observed negative differential resistance effect by the transmission spectra and transmission eigenstates. The results suggest that the zigzag graphene/BN nanoribbon heterojunction leads to the asymmetric current, causing the rectifying phenomenon, and the BN length in the scattering region can modulate the rectifying performance of zigzag graphene/BN nanoribbon heterojunction.