Qiu Xiaoqian, Wang Yiren, Jiang Yong
Key Laboratory for Nonferrous Metal Materials Science and Engineering (MOE), School of Materials Science and Engineering, Central South University, Changsha, 410083, China.
Phys Chem Chem Phys. 2021 May 26;23(20):11937-11943. doi: 10.1039/d1cp00156f.
The structural, electronic and magnetic properties of large area chemical vapor deposited monolayer MoS2 rely significantly on the presence of grain boundaries (GBs) and defects. In this study, first-principles calculations were performed to investigate the electronic and magnetic properties of transition metal doped MoS2 GBs. The experimentally observed 60° tilt GBs were demonstrated with four different atomic configurations and the nonmagnetic 4|8ud GB has the lowest formation energy among the considered models. Further calculations of 4|8ud GBs doped with TMs, such as V, Cr, Mn, Fe, Co and Ni, indicate that dopants can significantly lower the formation energies of the doped GBs compared to the perfect monolayer MoS2 by occupying the GB region instead of within the grains. Magnetism can be achieved in doped GB systems by careful defect engineering. CoMo, MnMo and Niint in 4|8ud GBs are predicted to be magnetic and simultaneously energetically favorable. The electron coupling between the doped TM and surrounding GB atoms is expected to induce magnetism and high electron mobilities into the systems. This study may pave the way for optimal design of MoS2-based electronic and spintronic devices.
大面积化学气相沉积单层二硫化钼的结构、电子和磁性特性在很大程度上依赖于晶界（GBs）和缺陷的存在。在本研究中，进行了第一性原理计算，以研究过渡金属掺杂的二硫化钼晶界的电子和磁性特性。通过四种不同的原子构型展示了实验观察到的60°倾斜晶界，在所考虑的模型中，非磁性的4|8ud晶界具有最低的形成能。对掺杂有V、Cr、Mn、Fe、Co和Ni等过渡金属的4|8ud晶界的进一步计算表明，与完美的单层二硫化钼相比，掺杂剂通过占据晶界区域而非晶粒内部，可显著降低掺杂晶界的形成能。通过精心设计缺陷，可在掺杂晶界系统中实现磁性。预测4|8ud晶界中的CoMo、MnMo和Niint具有磁性，并且在能量上同时有利。预计掺杂的过渡金属与周围晶界原子之间的电子耦合会在系统中诱导磁性和高电子迁移率。这项研究可能为基于二硫化钼的电子和自旋电子器件的优化设计铺平道路。
