Hoat D M, Van On Vo, Nguyen Duy Khanh, Naseri Mosayeb, Ponce-Pérez R, Vu Tuan V, Rivas-Silva J F, Hieu Nguyen N, Cocoletzi Gregorio H
Institute of Theoretical and Applied Research, Duy Tan University Hanoi 100000 Vietnam
Faculty of Natural Sciences, Duy Tan University Da Nang 550000 Vietnam.
RSC Adv. 2020 Nov 6;10(66):40411-40420. doi: 10.1039/d0ra05030j. eCollection 2020 Nov 2.
In this paper, we present a detailed investigation of the structural, electronic, and optical properties of pristine, nitrogenated, and fluorinated MgO monolayers using calculations. The two dimensional (2D) material stability is confirmed by the phonon dispersion curves and binding energies. Full functionalization causes notable changes in the monolayer structure and slightly reduces the chemical stability. The simulations predict that the MgO single layer is an indirect semiconductor with an energy gap of 3.481 (4.693) eV as determined by the GGA-PBE (HSE06) functional. The electronic structure of the MgO monolayer exhibits high sensitivity to chemical functionalization. Specifically, nitrogenation induces metallization of the MgO monolayer, while an indirect-direct band gap transition and band gap reduction of 81.34 (59.96)% are achieved by means of fluorination. Consequently, the functionalized single layers display strong optical absorption in the infrared and visible regimes. The results suggest that full nitrogenation and fluorination may be a quite effective approach to enhance the optoelectronic properties of the MgO monolayer for application in nano-devices.
在本文中，我们使用计算方法对原始的、氮化的和氟化的氧化镁单层的结构、电子和光学性质进行了详细研究。二维（2D）材料的稳定性通过声子色散曲线和结合能得到证实。完全功能化会导致单层结构发生显著变化，并略微降低化学稳定性。模拟结果预测，氧化镁单层是一种间接半导体，根据广义梯度近似（GGA-PBE）泛函（HSE06泛函）确定，其能隙为3.481（4.693）电子伏特。氧化镁单层的电子结构对化学功能化表现出高度敏感性。具体而言，氮化会使氧化镁单层金属化，而氟化则实现了间接-直接带隙跃迁以及81.34（59.96）%的带隙减小。因此，功能化的单层在红外和可见光区域表现出强烈的光吸收。结果表明，完全氮化和氟化可能是增强氧化镁单层光电性能以应用于纳米器件的一种非常有效的方法。
