Band Gap of Strained Graphene Nanoribbons
Band Gap of Strained Graphene Nanoribbons
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DOI：
10.1007/s12274-010-1022-4
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发表时间：
2010-03-01
期刊：
影响因子：
9.9
通讯作者：
Guo, Jing
中科院分区：
文献类型：
--
作者：
Lu, Yang;Guo, Jing
应变石墨烯纳米带（GNRs）的能带结构检查使用紧束缚的哈密顿量，这是直接相关的类型和应变的大小。与即使施加大的应变其带隙也保持接近于零的二维石墨烯相比，石墨烯纳米颗粒（GNR）的带隙对单轴应变和剪切应变都敏感。应变对GNR电子结构的影响强烈地依赖于它的边缘形状和结构指数。对于扶手椅型GNR，弱的单轴应变以线性方式改变带隙，而大的应变导致带隙的周期性振荡。另一方面，剪切应变总是倾向于减小带隙。对于锯齿形GNR，应变的作用是改变GNR边缘的自旋极化，从而调制带隙。一个简单的分析模型，这与数值计算结果一致，提出了解释的带隙的扶手椅GNRs应变的响应。
The band structures of strained graphene nanoribbons (GNRs) are examined using a tight-binding Hamiltonian that is directly related to the type and magnitude of strain. Compared to a two-dimensional graphene whose band gap remains close to zero even if a large strain is applied, the band gap of a graphene nanoribbon (GNR) is sensitive to both uniaxial and shear strains. The effect of strain on the electronic structure of a GNR depends strongly on its edge shape and structural indices. For an armchair GNR, a weak uniaxial strain changes the band gap in a linear fashion, whereas a large strain results in periodic oscillation of the band gap. On the other hand, shear strain always tends to reduce the band gap. For a zigzag GNR, the effect of strain is to change the spin polarization at the edges of GNR, and thereby modulate the band gap. A simple analytical model, which agrees with the numerical results, is proposed to interpret the response of the band gap to strain in armchair GNRs.