论文标题
MOS $ _2 $和WS $ _2 $的缺陷的明亮一面以及用于缺陷钝化的可推广的化学处理方案
The bright side of defects in MoS$_2$ and WS$_2$ and a generalizable chemical treatment protocol for defect passivation
论文作者
论文摘要
结构缺陷被广泛认为对单层过渡金属二核苷的光电特性有害，从而通过改善材料生长或生长后钝化来消除缺陷，从而努力消除缺陷。在这里，使用稳态和超快的光谱法得到了从头算计算的支持，我们证明了硫空位缺陷是激子陷阱。当前的化学处理不会钝化这些部位，从而导致迁移率降低和陷阱限制的光致发光。我们提出了一种基于钝化剂（例如硫醇或硫化物）与刘易斯酸联合使用的可推广治疗方案，以单层MOS $ _2 $和ws $ _2 $钝化硫的空位，使光致发光的光致发光最高275倍，同时维持动机。我们的发现提出了一种简单而理性的缺陷工程策略的途径，在该策略中，钝化代理会改变电子特性，从而允许设计新的异质结构。
Structural defects are widely regarded as detrimental to the optoelectronic properties of monolayer transition metal dichalcogenides, leading to concerted efforts to eliminate defects via improved materials growth or post-growth passivation. Here, using steady-state and ultrafast optical spectroscopy, supported by ab initio calculations, we demonstrate that sulfur vacancy defects act as exciton traps. Current chemical treatments do not passivate these sites, leading to decreased mobility and trap-limited photoluminescence. We present a generalizable treatment protocol based on the use of passivating agents such as thiols or sulfides in combination with a Lewis acid to passivate sulfur vacancies in monolayer MoS$_2$ and WS$_2$, increasing photoluminescence up to 275 fold, while maintaining mobilities. Our findings suggest a route for simple and rational defect engineering strategies, where the passivating agent varies the electronic properties, thereby allowing the design of new heterostructures.
