Coupling-Assisted Renormalization of Excitons and Vibrations in Compressed MoSe₂–WSe₂ Heterostructure

Journal Article · Thu Feb 22 00:00:00 UTC 2018 · Journal of Physical Chemistry. C

DOI: https://doi.org/10.1021/acs.jpcc.8b01453 · OSTI ID:1434727

Fu, Xinpeng ^[1]; Li, Fangfei  ^[1]; Lin, Jung-Fu ^[2]; Gong, Yuanbo ^[1]; Huang, Xiaoli ^[1]; Huang, Yanping ^[1]; Gao, Hanxue ^[1]; Zhou, Qiang ^[1]; Cui, Tian  ^[1]

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1. Jilin Univ., Changchun (China)
2. Univ. of Texas, Austin, TX (United States)

Vertical heterostructures (HSs) constructed with two-dimensional (2D) materials is expected to generate fascinating properties due to interlayer coupling between neighboring layers. However, interlayer coupling can be easily obscured by cross-contamination during transfer processes, rendering their experimental demonstration challenging. Here, we explore the coupling-assisted renormalization of excitons and vibrations in a mechanically fabricated MoSe₂–WSe₂ HS through high-pressure photoluminescence, Raman spectra, and density functional theory calculations. Accompanied by the interlayer coupling enhancement, the excitonic and vibrational renormalizations involving dimensionality and composition variations were achieved. A cycle of 2D–3D–2D excitonic evolution was disclosed and pressure-induced emergence of X^– exciton of MoSe₂ in HS was found reflecting the band structure transition in the MoSe₂–WSe₂ HS. The Raman spectra reveals that the coupled A₂" vibrations of WSe₂ and MoSe₂ in HS was stiffened and out-of-plane A₁' vibrations of WSe₂ and MoSe₂ in HS got coherent upon pressure modulation. Here, this coupling-assisted renormalization in MoSe₂–WSe₂ HS can be extended to other 2D layered HSs, which indicates the possibility to design a flexible HS with controlled excitonic and vibrational system for light-emitting diodes, excitonic, and photovoltaic devices.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: China Postdoctoral Science Foundation; NSF; National Basic Research Program of China; National Natural Science Foundation of China; USDOE Office of Science (SC)
• Grant/Contract Number: AC02-06CH11357; FG02-94ER14466
• OSTI ID: 1434727
• Journal Information: Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Journal Issue: 10 Vol. 122; ISSN 1932-7447
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
energy
excitons
layered materials
monolayers
oscillation