氧钝化圆形孔缺陷石墨烯的电学特性

Electrical Properties of Oxidation-Passivated Graphene Sheets with Circular Nanohole Defects

基于第一性原理方法,计算了氧钝化圆形孔缺陷石墨烯的电磁学特性.根据缺陷碳原子数目(Cn)的不同,圆形孔缺陷石墨烯呈现出了锯齿型(扶手椅型)边界,并且具有反铁磁(顺磁)基态,所有的圆形孔缺陷石墨烯都显现出了半导体性质.氧钝化的孔缺陷石墨烯均是半导体,而且呈现出了多样性的几何结构.研究发现,与氢钝化圆形孔缺陷石墨烯不同,氧钝化圆形孔缺陷石墨烯存在着更稳定的非平面结构.非平面结构的C6+O与C12+O展现出了半导体性质,而C24+O展现出了导体性质.研究表明:氧原子可以用于调节孔缺陷石墨烯的导电性质,并且为石墨烯孔结构器件设计提供有价值的理论指导.

Based on a first-principles approach, the electronic and magnetic properties of oxygen-passivated gra-phene sheets with circular nanohole defects are investigated. Depending on the number of the carbon atom (Cn) in defect, graphene nanoholes show zigzag ( armchair) shaped edge with anti-ferromagnetic ( paramagnetic) ground state, and all the graphene nanoholes are semiconductor. The results show that oxygen-passivated graphene nano-holes belong to semiconductor materials and have a rich geometrical structure. Unlike hydrogen-passivated graphene nanoholes, the oxygen-passivated graphene nanoholes can attain a lower energy configuration by adopting a nonpla-nar geometry. The nonplanar structures of C6+O and C12+O are semiconductor, however, the nonplanar structures of C24+O become a conductor. Our works suggest that oxygen atom could be used to manipulate the electronic struc-tures of graphene nanoholes and supply a valuable theoretical guidance for graphene-based electronic device design.