Enhanced Valley Polarization of Bilayer MoSe2 with Variable Stacking Order and Interlayer Coupling
Autor: | Jia-Cai Nie, Xingli Zhang, Lin He, Richeng Yu, Jun Zhou, Nan Liu, Jijun Zhao, Weifeng Zhang, Rui-Fen Dou, Yuanye Wang, Shiping Zhang, Shi-Qi Li, Yalin Liu, Junfeng Gao, Weipeng Wang |
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Rok vydání: | 2021 |
Předmět: |
Materials science
Bilayer Stacking 02 engineering and technology 021001 nanoscience & nanotechnology Polarization (waves) 01 natural sciences Molecular physics Ab initio quantum chemistry methods 0103 physical sciences Atom Valleytronics Monolayer General Materials Science Physical and Theoretical Chemistry 010306 general physics 0210 nano-technology Electronic band structure |
Zdroj: | The Journal of Physical Chemistry Letters. 12:5879-5888 |
ISSN: | 1948-7185 |
Popis: | In two-dimensional transitional metal dichalcogenides, tuning the spin-valley-layer coupling via changing layer numbers and stacking orders remains desirable for their application in valleytronics. Herein, six-point star-like MoSe2 nanoflakes simultaneously containing different atom registration regions from monolayer to bilayer with 2H and 3R stacking order were fabricated, and the valley polarizations were comparably investigated by circular polarized photoluminescent spectroscopy. The degree of valley polarization was detected to be about 12.5% in the monolayer and 10% in the 2H bilayer, but greatly upgraded to about 40% in the 3R bilayer MoSe2. This enhancement was attributed to the multiband spin splitting and generation of spin-dependent layer polarization for the 3R MoSe2 bilayer, which is well evidenced by our ab initio calculations of the energy band structures. Our results demonstrate that preparing TMD crystals with controllable stacking orders and interlayer coupling is a promising route to tune the valley index in TMDs for developing valleytronics technology. |
Databáze: | OpenAIRE |
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