▎ 摘　　要

Zigzag-edged graphene nanoribbons (ZGNRs) are used to build devices in which transport with high spin polarization is realized by first-principles simulations. At first, we dope the semiconducting ZGNRs with B atoms on both sides to obtain a metallic ribbon. Then, in one segment of this ribbon which acts as the scattering region, the B atoms at one edge are substituted by C atoms or by N atoms. It is found that such devices show very good spin filtering effect which originates from the interaction between the impurity atoms and the edge states. (C) 2009 American Institute of Physics. [doi:10.1063/1.3237165]