Enhanced Carrier−Exciton Interactions in Monolayer MoS2 under Applied Voltages
Enhanced Carrier−Exciton Interactions in Monolayer MoS2 under Applied Voltages
复制标题
外加电压下单层 MoS2 中载流子与激子相互作用的增强
DOI：
10.1021/acsami.0c02187
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发表时间：
2020
影响因子：
9.5
通讯作者：
Yichun Liu
中科院分区：
文献类型：
--
作者：
Yuanzheng Li;Weizhen Liu;Hang Ren;Qiushi Feng;Jiaxu Yan;Weiheng Zhong;Xing Xin;Haiyang Xu;Yichun Liu
二维过渡金属二硫属化物（TMD）中载流子-激子相互作用是限制其光电器件性能的关键因素之一。在这里，我们已经实验研究了载流子激子相互作用在单层二硫化钼为基础的双端器件。这种没有栅电极的双端器件通常被认为对于调制活性材料中的载流子浓度是无效的，而光致发光峰随着施加电压的增加而呈现出红移和衰减。时间分辨光致发光谱和光致发光谱多峰拟合证实了这种光致发光谱峰的变化是由于载流子-激子相互作用随电子浓度的增加而增强，从而导致带电激子的增加。为了表征载流子-激子相互作用的水平，使用质量作用模型建立了离面模的拉曼位移与电子浓度变化之间的定量关系。这一工作为理解TMD基双端光电子器件中载流子-激子相互作用提供了适当的补充。
Carrier–exciton interactions in two-dimensional transition metal dichalcogenides (TMDs) is one of the crucial elements for limiting the performance of their optoelectronic devices. Here, we have experimentally studied the carrier–exciton interactions in a monolayer MoS2-based two-terminal device. Such two-terminal device without a gate electrode is generally considered as invalid to modulate the carrier concentration in active materials, while the photoluminescence peak exhibits a red shift and decay with increasing applied voltages. Time-resolved photoluminescence spectroscopy and photoluminescence multipeak fittings verify that such changes of photoluminescence peaks result from enhanced carrier–exciton interactions with increasing electron concentration induce the charged exciton increasing. To characterize the level of the carrier–exciton interactions, a quantitative relationship between the Raman shift of out-of-plane mode and changes in electron concentration has been established using the mass action model. This work provides an appropriate supplement for understanding the carrier–exciton interactions in TMD-based two-terminal optoelectronic devices.