Tensile Strain Controlled Photo-Generated Carrier Dynamics at van der Waals Heterostructure Interface
Tensile Strain Controlled Photo-Generated Carrier Dynamics at van der Waals Heterostructure Interface
复制标题
范德华异质结构界面处的拉伸应变控制光生载流子动力学
DOI：
10.1021/acs.jpclett.9b03534
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Zhao Jin
中科院分区：
文献类型：
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作者：
Tian Yunzhe;Zheng Qijing;Zhao Jin
定制光生载流子动力学将使二维(2D)材料高度适应各种应用场景。在时间域从头算非绝热分子动力学模拟的基础上，我们发现4%的张应变可以抑制范德华异质结MoS_2/WS_2界面的电子转移。我们的分析表明，电子-空穴对在WS2中的K谷被激发后，由于K谷中弱的层间耦合，电子从WS2@K到MoS2@K的直接电子转移非常困难，因此它通过T谷发生，即WS2@K-MoS2@T-MoS2@K。当施加张应变时，WS2@K的能量降低，从而抑制了电子转移。我们的研究表明，通过外部应变来调谐层间电荷转移动力学是可能的，这为基于2D材料的光子器件的功能设计提供了有价值的见解。
Customizing the photogenerated carrier dynamics would make the two-dimensional (2D) materials highly adaptable to various application scenarios. On the basis of time-domain ab initio nonadiabatic molecular dynamics simulation, we find that 4% tensile strain can suppress the electron transfer at the van der Waals heterostructure MoS2/WS2interface. Our analysis shows that after the electron–hole pair is excited in the K valley in WS2direct electron transfer from WS2@K to MoS2@K is very difficult because of the weak interlayer coupling in the K valley, and thus, it happens through the T valley as WS2@K–MoS2@T–MoS2@K. When the tensile strain is applied, the energy of WS2@K is decreased, resulting in the suppression of electron transfer. Our study suggests that tuning of the interlayer charge-transfer dynamics by external strain is possible, which provides valuable insights into the functional design of photonic devices based on 2D materials.