▎ 摘　　要

Electronic properties of a semiconducting armchair graphene nanoribbon on SiO2 are examined using first-principles calculations and taking into account the van der Waals interaction. Unlike semiconducting carbon nanotubes, which exhibit variations in band gap on SiO2, the nanoribbon is found to retain its band gap on SiO2, regardless of the separation distance or the dielectric's surface type-crystalline or amorphous. The interfacial interaction leads to electron-transfer from the nanoribbon to the dielectric. Moreover, for crystalline SiO2, the quantity of electron-transfer and the binding energy depend strongly on the type of surface termination and weakly on the binding sites. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3657494]