Baskurt Mehmet, Kang Jun, Sahin Hasan
Department of Photonics, Izmir Institute of Technology, Izmir, 35430, Turkey.
Beijing Computational Science Research Center, Beijing, 100193, China.
Phys Chem Chem Phys. 2020 Feb 7;22(5):2949-2954. doi: 10.1039/c9cp06015d. Epub 2020 Jan 17.
Using first-principles calculations, the structural, vibrational, and electronic properties of single-layered calcium fluoride (CaF) are investigated. The dynamical stability of 1T-CaF is confirmed by the phonon dispersions. Raman active vibrational modes of 1T-CaF enable its characterization via Raman spectroscopy. In addition, the calculated electronic properties of 1T-CaF 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 CaF are investigated for two main edge orientations, namely zigzag and armchair, and it is revealed that both structures maintain the 1T nature of CaF without any structural edge reconstructions. Electronically, both types of CaF nanoribbons display robust insulating behavior with respect to the nanoribbon width. The results show that both the 2D and 1D forms of 1T-CaF show potential in nanoelectronics as an alternative to the widely-used insulator h-BN with its similar properties and wider electronic band gap.
采用第一性原理计算方法，研究了单层氟化钙（CaF）的结构、振动和电子性质。通过声子色散证实了1T-CaF的动力学稳定性。1T-CaF的拉曼活性振动模式使其能够通过拉曼光谱进行表征。此外，计算得到的1T-CaF的电子性质证实其具有绝缘行为，间接宽带隙大于著名的单层绝缘体h-BN。此外，研究了CaF的一维纳米带的两种主要边缘取向，即锯齿形和扶手椅形，结果表明这两种结构均保持了CaF的1T性质，且无任何结构边缘重构。在电子方面，两种类型的CaF纳米带相对于纳米带宽度均表现出稳健的绝缘行为。结果表明，1T-CaF的二维和一维形式在纳米电子学中均具有潜力，可作为广泛使用的具有相似性质和更宽电子带隙的绝缘体h-BN的替代品。
