Understanding Dopant–Host Interactions on Electronic Structures and Optical Properties in Ce‐Doped WS2 Monolayers
Understanding Dopant–Host Interactions on Electronic Structures and Optical Properties in Ce‐Doped WS2 Monolayers
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DOI：
10.1002/adfm.202301533
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发表时间：
2023-04
影响因子：
19
通讯作者：
Caixia Ren;J. Peng;Hu Chen;Weili Zhang;X.Y. Pan;Hangxin Bai;Yongzheng Wang;F. Jing;
中科院分区：
文献类型：
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作者：
Caixia Ren;J. Peng;Hu Chen;Weili Zhang;X.Y. Pan;Hangxin Bai;Yongzheng Wang;F. Jing;
过渡金属二卤化物(TMDs)的稀土替代掺杂有望成为设计TMDs光学、电学和光电性质的一种有前途的策略。了解稀土掺杂与二维TMDs基质之间的相互作用是其深入研究需要解决的关键问题之一。本文将扫描隧道显微镜与光学特性相结合，研究了物理气相沉积生长的Ce掺杂WS2单层中Ce掺杂与WS2之间的相互作用。研究发现，高度各向异性的晶场能有效地分裂Ce掺杂的f轨道能级。分裂能级中的电子可以束缚Ce掺杂WS2的价带极大处的空穴，形成光学亮激子。随着泵浦通量的增加，这些激子与自由的A激子发生碰撞，缩短了A激子的寿命。本研究对基于稀土掺杂TMDs的光学、电子学和光电子学器件的设计和制备具有一定的参考价值。
Substitutional lanthanide doping of 2D transition metal dichalcogenides (TMDs) is expected to be a promising strategy to engineer optical, electronic, and optoelectronic properties of TMDs. Understanding the interactions between lanthanide dopants and 2D TMDs host is one of the key problems to be resolved for their profound research studies. Herein, the interactions between Ce dopants and monolayer WS2 in a physical vapor deposition grown Ce‐doped WS2 monolayer are studied by combining scanning tunneling microscopy with optical characterizations with high spatial and temporal resolution. It is found that the highly anisotropic crystal field can effectively split the energy levels of the Ce dopants’ f orbital. The electrons in the split energy levels can bind the holes in the valence band maximum of the Ce‐doped WS2, forming optical bright excitons. These excitons collide with the free A excitons when increasing the pump fluences, reducing the A exciton's lifetime. This study may be beneficial for the design and fabrication of optical, electronic, and optoelectronic devices based on lanthanide‐doped TMDs.