School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China.
Phys Chem Chem Phys. 2019 Sep 18;21(36):20073-20082. doi: 10.1039/c9cp03580j.
The van der Waals heterostructures created by stacking two monolayer semiconductors have been rapidly developed experimentally and exhibit various unique physical properties. In this work, we investigate the effects of Se atom substitution and 3d-TM atom doping on the structural, electronic, and magnetic properties of the MoSe2/h-BN heterostructure, by using first-principles calculations based on density functional theory (DFT). It is found that Se atom substitution could considerably enhance the band gaps of MoSe2/h-BN heterostructures. With an increase in the substitution concentration, the energy band changes from an indirect to a direct band gap when the substitution concentration exceeds a critical value. For 3d-TM atom doping, it is shown that V-, Mn-, Fe-, and Co-doped systems exhibit a half-metallic state and magnetic behavior, while there is no spin polarization in the Ni-doped case. The results provide a theoretical basis for the development of diluted magnetic semiconductors and spin devices based on the MoSxSe2-x/h-BN heterostructure.
由堆叠两个单层半导体形成的范德华异质结构在实验上得到了快速发展，并表现出各种独特的物理性质。在这项工作中，我们通过基于密度泛函理论（DFT）的第一性原理计算，研究了 Se 原子取代和 3d-TM 原子掺杂对 MoSe2/h-BN 异质结构的结构、电子和磁性性质的影响。结果表明，Se 原子取代可以显著提高 MoSe2/h-BN 异质结构的能带隙。随着取代浓度的增加，当取代浓度超过一个临界值时，能带从间接带隙变为直接带隙。对于 3d-TM 原子掺杂，结果表明 V、Mn、Fe 和 Co 掺杂的体系表现出半金属态和磁性行为，而 Ni 掺杂的体系没有自旋极化。这些结果为基于 MoSxSe2-x/h-BN 异质结构的稀磁半导体和自旋器件的发展提供了理论基础。
