JOURNAL OF ALLOYS AND COMPOUNDS | 卷:868 |
New stable two dimensional silicon carbide nanosheets | |
Article | |
Wei, Qun1  Yang, Ying2,3  Yang, Guang2,4  Peng, Xihong2  | |
[1] Xidian Univ, Sch Phys & Optoelect Engn, Xian 710071, Shaanxi, Peoples R China | |
[2] Arizona State Univ, Coll Integrat Sci & Arts, Mesa, AZ 85212 USA | |
[3] Xian Univ Technol, Sch Automat & Informat Engn, Xian 710048, Shaanxi, Peoples R China | |
[4] Hebei Univ Sci & Technol, Sch Sci, Shijiazhuang 050018, Hebei, Peoples R China | |
关键词: 2D silicon carbide; Strain-stress relation; Moduli; Band structure; Band gap; Hydrogenation; Strain engineering; | |
DOI : 10.1016/j.jallcom.2021.159201 | |
来源: Elsevier | |
【 摘 要 】
We predict the existence of new two dimensional (2D) silicon carbide nanostructures employing ab initio density-functional theory calculations. These structures are composed of tetragonal and hexagonal rings with C-C and Si-C bonds arranged in a buckling plane. They are proven to be thermodynamically and mechanically stable with relatively low formation energy, implying potential fabrication in labs. They exhibit strong ductility and anisotropicity from their strain-stress relations and directional dependence of mechanical moduli. The materials maintain phonon stability upon the application of mechanical strain up to 27% with fantastic ductile property. The proposed 2D SiC2 structure possesses a tiny direct band gap of 0.02 eV predicted using HSE06 functional and the band gap can be opened up through multiple approaches such as hydrogenation and strain application. The gap values can be strategically tuned in the range of 0.02-1.72 eV and the direct/indirect gap nature can be further manipulated. In contrast, a closely related isostructural 2D SiC shows an indirect HSE band gap of 1.80 eV and strain engineering its value between 0.0-1.95 eV. The unique properties in these newly proposed structures might have potential applications in future nanomechanics and electronics. (C) 2021 Elsevier B.V. All rights reserved.
【 授权许可】
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