单空位缺陷诱导的扶手椅型石墨烯纳米带电学性能的转变

Single-vacancy-induced transformation of electronic properties in armchair graphene nanoribbons

本文基于密度泛函理论的第一性原理计算了单空位缺陷对扶手椅型石墨烯纳米带电学特性的影响.计算结果表明:当单空位位于纳米带边缘位置时,系统结构最稳定.不同位置上单空位缺陷的引入都会使得原本为半导体的本征扶手椅型石墨烯纳米带变成金属性;随着单空位浓度的减小,其对纳米带能带结构的影响逐渐减弱;随着纳米带宽度的增大,表征其金属性的特征值表现出震荡性的减弱.单空位缺陷诱导的扶手椅型纳米带的半导体特性到金属特性的转变为石墨烯在电子器件中的应用提供了理论指导.

Using first principle and based on the density functional theory, we have studied the effect of the single vacancy on the electronic properties of armchair graphene nanoribbons （AGNRs）. Results show that the system is the most stable when the vacancy is at edge site. It is found that AGNRs always become metallic, regardless of the vacancy position. As the vacancy concentration decreases, the influence of the vacancy position on band structures becomes weaker and weaker. As the ribbon width increases, the particular value characterizing the strength of metallicity decreases in oscillation. Vacancy-induced semiconductor to metal transition in AGNRs provides the theoretical direction for the application of graphene in the electrionic devices.