Two-Dimensional Magnetic Semiconductors Based on Transition-Metal Dichalcogenides VX2(X = S, Se, Te) and Similar Layered Compounds VI2and Co(OH)2

We present a new type of two-dimensional (2D) magnetic semiconductor based on transition-metal dichalcogenides MX2(M = V, Co; X = S, Se, Te, I, OH) via first-principles calculations. The obtained band gaps of monolayer (ML) VS2, VSe2, and VTe2in the H-phase given from the generalized gradient approximation (GGA) are respectively 0.05, 0.22, and 0.20 eV, all with integer magnetic moments of 1.0 muB, while ML VI2and Co(OH)2in the T-phase exhibit energy gaps of 0.96 and 0.08 eV, respectively, with integer magnetic moments of 3.0 muB. The GGA plus on-site Coulomb interaction U (GGA + U) scheme, which takes the electron-electron correlations in 3d orbitals into account, enhances the exchange splittings, and raises the energy gap of these MLs up to 0.4 to 3 eV. They agree very well with our calculated gaps based on the hybridized functional Heyd-Scuseria-Ernzerhof (HSE) of 0.6 to 3 eV. The wide range of energy gaps provides flexible applications in spintronics. All the calculations demonstrate 100% spin polarized bands around the Fermi level for these MLs. Combining the semiconducting energy gap and the fully spin polarized valence and conduction bands in a single-layer MX2, this new type 2D magnetic semiconductor shows great potential in future spintronics applications.

我们提出了一种新型的二维（2D）磁性半导体，该磁性半导体基于过渡金属二核苷酸MX2（M = V，CO; X = S，SE，TE，TE，I，I，OH）通过第一原则计算。获得的单层（ML）VS2，VSE2和VTE2IN所获得的带隙分别从广义梯度近似（GGA）给出的H期分别为0.05、0.22和0.20 eV，所有均具有1.0 MUB的整数磁矩，而ML VI2和ML VI2和ML磁矩为1.0 mub CO（OH）2在用整数磁性的T阶段分别显示为0.96和0.08 eV的能隙3.0 Mub的时刻。 GGA Plus现场库仑相互作用U（GGA + U）方案，该方案将3D轨道中的电子电子相关性考虑在内，增强了交换分割，并提高了这些MLS的能量差距为0.4至3 eV。他们与基于0.6至3 eV的杂交功能性HEYD-SCUSERIA-ERNZERHOF（HSE）基于我们计算出的差距非常吻合。宽范围的能量差距可在旋转中的灵活应用中进行灵活的应用。所有计算均表明这些MLS围绕费米水平的100％自旋极化带。在单层MX2中，将半导体的能量隙和完全自旋的偏振价和传导带相结合，这款新型2D磁性半导体在将来的Spintronics应用中具有巨大的潜力。