▎ 摘　　要

First principles calculations were performed to study strain effects on band gap of armchair graphene nanoribbons (AGNRs) with different edge passivation, including H, O, and OH group. The band gap of the H-passivated AGNRs shows a nearly periodic zigzag variation under strain. For O and OH passivation, the zigzag patterns are significantly shifted by a modified quantum confinement due to the edges. In addition, the band gap of the O-passivated AGNRs experiences a direct-to-indirect transition with sufficient tensile strain (similar to 5%). The indirect gap reduces to zero with further increased strain. (c) 2011 American Institute of Physics. [doi:10.1063/1.3536481]