通过稀土（Er、Tm、Lu）掺杂改造 WS2 单层空位缺陷：第一性原理研究,Physica Status Solidi (B) - Basic Solid State Physics

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通过稀土（Er、Tm、Lu）掺杂改造 WS2 单层空位缺陷：第一性原理研究
Physica Status Solidi (B) - Basic Solid State Physics ( IF 1.5 ) Pub Date : 2023-05-09 , DOI: 10.1002/pssb.202300055
Yang Zhao _{1,

2} , Bing Yan ₃ , Xianxiao Liang _{1,

2} , Shaoxiang Liu ₂ , Xuan Shi ₂ , Hongquan Zhao ₂

Affiliation

二维 (2D) 材料中的空位缺陷对其性能至关重要。稀土原子对空位缺陷的替代掺杂导致了多种材料的多功能性，但其效果和相应的机制还远未得到解答。在此，基于哈伯德校正（DFT+U）的密度泛函理论，研究了WS ₂单层中空位缺陷和稀土（RE = Er，Tm，Lu）掺杂的电子和光学性质。缺陷系统和掺杂系统的形成能分别在富W和富S条件下计算。_{WS 2}的带隙4 × 4 × 1 超晶胞中存在一个 W 缺陷时，从直接转变为间接，而 S 缺陷不会改变超晶胞的带隙类型。当稀土原子掺杂在钨缺陷中时，带隙恢复为正向。具有本征缺陷和[W]缺陷中掺杂Lu的WS ₂超级电池表现出非磁性，而Er和Tm掺杂的超级电池表现出明显的磁性。当RE原子取代W位点时，介电函数的虚部和吸收系数从可见光到近红外急剧增加，并且由于价带最大值的上升，带隙缩小。_{这项工作证明了 2D WS 2}中的稀土掺杂是带隙和载流子工程的有效技术。

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Engineering of Vacancy Defects in WS2 Monolayer by Rare-Earth (Er, Tm, Lu) Doping: A First-Principles Study

Vacancy defects in two-dimensional (2D) materials are critical to their properties. The substitutional doping in vacancy defects by rare-earth atoms results in diverse material versatilities, but the effects and the corresponding mechanisms are far from being answered. Herein, the electronic and optical properties of vacancy defects and lanthanide rare-earth (RE = Er, Tm, Lu) doping in WS₂ monolayers are studied based on density functional theory with Hubbard correction (DFT + U). The formation energies of defective and doped systems are calculated under W-rich and S-rich conditions, respectively. The bandgap of WS₂ with one W-defect in a 4 × 4 × 1 supercell changes from direct to indirect, while S-defect does not change the bandgap type of the supercell. When RE atoms are doped in the W-defect, the bandgap returns to direct. WS₂ supercells with intrinsic defects and Lu doped in [W] defect show the nonmagnetic property, while Er- and Tm-doped supercells show obvious magnetic properties. The imaginary part of dielectric function and absorption coefficients increase drastically from visible to near-infrared as RE atoms substitute W sites, and the bandgap shrinks due to the rise of the valance band maximum. This work proves RE doping in 2D WS₂ is an effective technique for bandgap and carrier engineering.

更新日期：2023-05-09

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