▎ 摘　　要

We study the electron transport properties of the p-n junction based on zigzag graphene nanoribbon, including its magnetic moment, charge-density distribution, and also the spin-resolved transmission probability. A nanoscale system of width approximate to 2 nm and length approximate to 15 nm is considered. It is shown that the magnetization of the edges is quenched in the p and n regions, but can be preserved in the center part of the p-n junction. We find that the electrons can tunnel through the junction by the localized modes, which exist at the interface of the p and n regions. In the presence of external transverse electric fields, we show that the electron current through the p-n junction will be spin-polarized when the zigzag graphene nanoribbon is in a half-metal state, and the current is switched off when a charge-polarized state is obtained. (C) 2011 American Institute of Physics. [doi:10.1063/1.3667175]