Edge effects in finite elongated graphene nanoribbons
Edge effects in finite elongated graphene nanoribbons
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DOI：
10.1103/physrevb.76.233401
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发表时间：
2007-12-01
影响因子：
3.7
通讯作者：
Scuseria, Gustavo E.
中科院分区：
文献类型：
--
作者：
Hod, Oded;Peralta, Juan E.;Scuseria, Gustavo E.
我们分析的相关性，有限尺寸效应的电子结构的长石墨烯纳米带使用分而治之的密度泛函方法。我们发现，对于氢封端的石墨烯纳米带，在一个无限的石墨烯纳米管的状态密度中出现的大部分物理特征在40 nm的长度被恢复。然而，即使是最长的系统（72纳米长）考虑明显的边缘效应出现在附近的费米能量。这些边缘状态的权重与带的长度成反比，并且预期它们仅在微米量级的带长度处变得可忽略不计。我们的研究结果表明，在设计基于石墨烯纳米带的新型纳米电子器件时，应仔细考虑有限尺寸和边缘效应。这些结论预计将适用于其他一维系统，如碳纳米管，导电聚合物和DNA分子。
We analyze the relevance of finite-size effects to the electronic structure of long graphene nanoribbons using a divide and conquer density functional approach. We find that for hydrogen terminated graphene nanoribbons, most of the physical features appearing in the density of states of an infinite graphene nanoribbon are recovered at a length of 40 nm. Nevertheless, even for the longest systems considered (72 nm long) pronounced edge effects appear in the vicinity of the Fermi energy. The weight of these edge states scales inversely with the length of the ribbon, and they are expected to become negligible only at ribbon lengths of the order of micrometers. Our results indicate that careful consideration of finite-size and edge effects should be applied when designing new nanoelectronic devices based on graphene nanoribbons. These conclusions are expected to hold for other one-dimensional systems such as carbon nanotubes, conducting polymers, and DNA molecules.