▎ 摘　　要

Configuration-dependent geometric and electronic structures of bilayer zigzag graphene nanoribbons are investigated by first-principles calculations. These properties are dominated by the stacking configurations, interlayer edge-edge interactions, spin arrangements, and ribbon widths. The optimal configuration exists between the AA and AB(alpha) (AA' and AB(beta)) stackings, mainly owing to the competition of the stacking and quantum confinement effects. The interlayer edge-edge interactions lead to the destruction or creation of magnetism and cause the AA-stacked system to exhibit a pair of metallic linear bands. However, other stacked nanoribbons are exclusively indirect- or direct-gap semiconductors. The splitting of spin-up and spin-down states could be induced by different magnetic environments. The band-edge states, with a high density of states, are sensitive to changes in the relative displacement. (C) 2014 Elsevier Ltd. All rights reserved.