Octahedrally coordinated single layered CaF2: robust insulating behaviour
Octahedrally coordinated single layered CaF2: robust insulating behaviour
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DOI：
10.1039/c9cp06015d
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发表时间：
2020-02-07
影响因子：
3.3
通讯作者：
Sahin, Hasan
中科院分区：
文献类型：
--
作者：
Baskurt, Mehmet;Kang, Jun;Sahin, Hasan
采用第一性原理计算，研究了单层氟化钙（CaF 2）的结构、振动和电子性质。1 T-CaF_2的声子色散证实了其动力学稳定性。1 T-CaF 2的拉曼活性振动模式使得能够通过拉曼光谱对其进行表征。此外，计算的1 T-CaF 2的电子性质证实了具有间接宽带隙的绝缘行为，该宽带隙大于众所周知的单层绝缘体h-BN的宽带隙。此外，一维纳米带的CaF 2的两个主要的边缘方向，即锯齿形和扶手椅，研究表明，这两种结构保持1 T性质的CaF 2没有任何结构的边缘重建。电子，这两种类型的CaF 2纳米带显示出强大的绝缘行为相对于纳米取向度的宽度。结果表明，二维和一维1 T-CaF 2晶体具有与h-BN类似的性质和更宽的电子带隙，在纳米电子学领域具有广阔的应用前景。
Using first-principles calculations, the structural, vibrational, and electronic properties of single-layered calcium fluoride (CaF2) are investigated. The dynamical stability of 1T-CaF2 is confirmed by the phonon dispersions. Raman active vibrational modes of 1T-CaF2 enable its characterization via Raman spectroscopy. In addition, the calculated electronic properties of 1T-CaF2 confirmed insulating behavior with an indirect wide band gap which is larger than that of a well-known single-layered insulator, h-BN. Moreover, one-dimensional nanoribbons of CaF2 are investigated for two main edge orientations, namely zigzag and armchair, and it is revealed that both structures maintain the 1T nature of CaF2 without any structural edge reconstructions. Electronically, both types of CaF2 nanoribbons display robust insulating behavior with respect to the nanoribbon width. The results show that both the 2D and 1D forms of 1T-CaF2 show potential in nanoelectronics as an alternative to the widely-used insulator h-BN with its similar properties and wider electronic band gap.