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石墨烯纳米带(GNRs)是一种重要的纳米材料,碳纳米管可看作是GNRs卷曲而成的无缝圆筒.利用基于密度泛函理论的第一性原理方法,系统研究了GNRs卷曲变形到不同几何构型时,其电子特性,包括能带结构(特别是带隙)、态密度、透射谱的变化规律.结果表明:无论是锯齿型GNRs(ZGNRs)或扶手椅型GNRs(AGNRs),在其卷曲成管之前,其电子特性对卷曲形变均不敏感,这意味着GNRs的电子结构及输运特性有较强地抵抗卷曲变形的能力.当GNRs卷曲成管后,ZGNRs和AGNRs表现出完全不同的性质,ZGNRs几乎保持金属性不变或变为准金属;但AGNRs的电子特性有较大的变化,出现不同带隙半导体、准金属之间的转变,这也许密切关系到碳纳米管管口周长方向上的周期性边界条件及量子禁锢的改变.这些研究对于了解GNRs电子特性的卷曲效应、以及GNRs与碳纳米管电子特性的关系(结构与特性的关系)有重要意义.
Graphene nanoribbons (GNRs) are important nanomaterials, and CNTs can be regarded as a seamless cylinder of curled GNRs. By using the first principles method based on density functional theory, GNRs curling The electronic properties, including the band structure (especially the bandgap), the density of state and the change of transmission spectra, were observed when the samples were deformed into different geometric configurations.The results showed that both the zigzag type GNRs and the armchair type GNRs AGNRs ), Their electronic properties are not sensitive to the crimp deformation before they are crimped into tubes, which means that the electronic structure and transport properties of GNRs are more resistant to the crimping deformation.When GNRs are crimped into tubes, ZGNRs and AGNRs Show completely different properties. ZGNRs almost remain the same or become metalloid; however, the electronic properties of AGNRs vary greatly, resulting in the transition between different bandgap semiconductors and metalloids, which may be closely related to the carbon Periodic boundary conditions and quantum confinement changes in the circumferential direction of the nanotube nozzle These studies are important to understand the curling effect of electronic properties of GNRs and the relationship between the electronic properties of GNRs and carbon nanotubes (structure-property relationship) .