▎ 摘　　要

On the basis of the density functional theory combined with the effective screening medium method, we studied the electronic structure of graphene nanoribbons with zigzag edges, which are terminated by functional groups. The work function of the nanoribbons is sensitive to the functional groups. The edge state inherent in the zigzag edges is robust against edge functionalization. OH termination causes the injection of electrons into the nearly free electron states situated alongside the nanoribbons, resulting in the formation of free electron channels outside the nanoribbons. We also demonstrated that the polarity of zigzag graphene nanoribbons is controllable by the asymmetrical functionalization of their edges. (C) 2017 The Japan Society of Applied Physics