石墨
纳米孔
Dirac(视频压缩格式)
单层
半金属
电子能带结构
凝聚态物理
费米能量
费米能级
材料科学
物理
纳米技术
带隙
石墨烯
量子力学
电子
中微子
作者
Linyang Li,Xiangru Kong,F. M. Peeters
出处
期刊:Carbon
[Elsevier]
日期:2019-01-01
卷期号:141: 712-718
被引量:42
标识
DOI:10.1016/j.carbon.2018.09.078
摘要
Two-dimensional (2D) carbon materials play an important role in nanomaterials. We propose a new carbon monolayer, named hexagonal-4,4,4-graphyne (H4,4,4-graphyne), which is a nanoporous structure composed of rectangular carbon rings and triple bonds of carbon. Using first-principles calculations, we systematically studied the structure, stability, and band structure of this new material. We found that its total energy is lower than that of experimentally synthesized β-graphdiyne and it is stable at least up to 1500 K. In contrast to the single Dirac point band structure of other 2D carbon monolayers, the band structure of H4,4,4-graphyne exhibits double Dirac points along the high-symmetry points and the corresponding Fermi velocities (1.04–1.27 × 106 m/s) are asymmetric and higher than that of graphene. The origin of these double Dirac points is traced back to the nodal line states, which can be well explained by a tight-binding model. The H4,4,4-graphyne forms a moiré superstructure when placed on top of a hexagonal boron nitride substrate. These properties make H4,4,4-graphyne a promising semimetal material for applications in high-speed electronic devices.
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