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论文类型： 期刊论文

发表时间： 2013-04-01

发表刊物： CARBON

收录刊物： SCIE、EI

卷号： 55

页面范围： 151-159

ISSN号： 0008-6223

摘要： The graphene grain boundaries with periodic length up to 18 angstrom have been studied using density functional theory. Atomic structures, thermodynamic stabilities and electronic properties of 40 grain boundaries with symmetric and nonsymmetric structures were investigated. According to the arrangements of pentagons and heptagons on the boundary, grain boundaries were cataloged into four classes. Some nonsymmetric grain boundaries constructed here have identical misorientation angles to the experimentally observed ones. The formation energies of grain boundaries can be correlated with the misorientation angle and inflection angle. Nonsymmetric grain boundaries possess comparable formation energies to their symmetric counterparts when the periodic length along the defect line is larger than 1 nm. Analysis of electronic density of states shows that the existence of a grain boundary usually increases the density of states near the Fermi level, whereas some symmetric grain boundaries can open a small band gap due to local sp(2)-to-sp(3) rehybridization. (C) 2012 Elsevier Ltd. All rights reserved.