Effects of dielectric screening on the excitonic and critical points properties of WS2/MoS2 heterostructures | |
X. D. Zhu,J. B. He,R. J. Zhang,C. X. Cong,Y. X. Zheng,H. Zhang,S. W. Zhang and L. Y. Chen | |
刊名 | Nanoscale |
2020 | |
卷号 | 12期号:46页码:23732-23739 |
ISSN号 | 2040-3364 |
DOI | 10.1039/d0nr04591h |
英文摘要 | Vertical van der Waals heterostructures have aroused great attention for their promising application in next-generation nanoelectronic and optoelectronic devices. The dielectric screening effect plays a key role in the properties of two-dimensional (2D) heterostructures. Here, we studied the dielectric screening effects on the excitonic properties and critical points (CPs) of the WS2/MoS2 heterostructure using spectroscopic ellipsometry (SE). Owing to the type-II band alignment of the WS2/MoS2 heterostructure, charged carriers spatially separated and created an interlayer exciton, and the transition energy and binding energy have been accurately found to be 1.58 +/- 0.050 eV and 431.39 +/- 127.818 meV by SE, respectively. We found that stacking the WS2/MoS2 vertical heterostructure increases the effective dielectric screening compared with the monolayer counterparts. The increased effective dielectric screening in the WS2/MoS2 heterostructure weakens the long-range Coulomb force between electrons and holes. Consequently, the quasi-particle band gap and the exciton binding energies are reduced, and because of the orbital overlap, more CPs are produced in the WS2/MoS2 heterostructure in the high photon energy range. Our results not only shed light on the interpretation of recent first-principles studies, but also provide important physical support for improving the performance of heterostructure-based optoelectronic devices with tunable functionalities. |
URL标识 | 查看原文 |
语种 | 英语 |
内容类型 | 期刊论文 |
源URL | [http://ir.ciomp.ac.cn/handle/181722/64479] |
专题 | 中国科学院长春光学精密机械与物理研究所 |
推荐引用方式 GB/T 7714 | X. D. Zhu,J. B. He,R. J. Zhang,C. X. Cong,Y. X. Zheng,H. Zhang,S. W. Zhang and L. Y. Chen. Effects of dielectric screening on the excitonic and critical points properties of WS2/MoS2 heterostructures[J]. Nanoscale,2020,12(46):23732-23739. |
APA | X. D. Zhu,J. B. He,R. J. Zhang,C. X. Cong,Y. X. Zheng,H. Zhang,S. W. Zhang and L. Y. Chen.(2020).Effects of dielectric screening on the excitonic and critical points properties of WS2/MoS2 heterostructures.Nanoscale,12(46),23732-23739. |
MLA | X. D. Zhu,J. B. He,R. J. Zhang,C. X. Cong,Y. X. Zheng,H. Zhang,S. W. Zhang and L. Y. Chen."Effects of dielectric screening on the excitonic and critical points properties of WS2/MoS2 heterostructures".Nanoscale 12.46(2020):23732-23739. |
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