Yang Yi, Fan Xiao-Li, Pan Rui, Guo Wen-Jun
State Key Laboratory of Solidification Processing, School of Material Science and Engineering, Northwestern Polytechnic University, 127 YouYi Western Road, Xi'an, Shaanxi 710072, China.
Phys Chem Chem Phys. 2016 Apr 21;18(15):10152-7. doi: 10.1039/c6cp00701e. Epub 2016 Mar 24.
By performing first-principles calculations, we have studied the structural, electronic and magnetic properties of transition-metal (TM) (Mn, Fe, Co, Ni) doped bilayer WS2 in both the AA and AB configurations. We have examined three probable interlayer doping positions, and found that the doped TM atoms prefer to stay below the S atoms. The TM atoms are covalently bound to the upper layer and lower layer S atoms with binding energies ranging from -0.74 to -1.72 eV for the AA configuration and from -0.69 to -1.80 eV for the AB configuration. Our calculations indicate that all the studied configurations are still semiconductors although the corresponding band gaps reduce a lot, except for the Fe-doped AA configuration which changes to a semi-metal with one spin state cross over at the Fermi level. Additional, our calculations indicate that Mn, Fe and Co-doping induces magnetism in both the AA and AB configurations. More importantly, a high spin polarization of 100% at the Fermi level is achieved in the Co-doped AA configuration and the Mn and Fe-doped AB configurations, which implies the potential for application in spintronic devices.
通过进行第一性原理计算，我们研究了在AA和AB构型下过渡金属（TM）（Mn、Fe、Co、Ni）掺杂双层WS2的结构、电子和磁性性质。我们考察了三个可能的层间掺杂位置，发现掺杂的TM原子倾向于位于S原子下方。对于AA构型，TM原子与上层和下层的S原子共价结合，结合能范围为-0.74至-1.72 eV；对于AB构型，结合能范围为-0.69至-1.80 eV。我们的计算表明，所有研究的构型仍然是半导体，尽管相应的带隙大幅减小，但除了Fe掺杂的AA构型变为半金属且在费米能级处有一个自旋态交叉外。此外，我们的计算表明，Mn、Fe和Co掺杂在AA和AB构型中都能诱导磁性。更重要的是，在Co掺杂的AA构型以及Mn和Fe掺杂的AB构型中，在费米能级处实现了100%的高自旋极化，这意味着其在自旋电子器件中的应用潜力。
