Quasiparticle band structures and optical properties of twisted bilayer MoS2. (29th December 2021)

• Record Type: Journal Article
• Authors: He, Fuli; Li, Jia; Li, Linyang; Mao, Xiujuan; Liu, Ze; Teng, Sukai; Wang, Jiaxi; Wang, Yafan
• Is Part Of: Europhysics letters. Volume 136:Number 1(2021)
• Publication Date: 2021-12-29
• Subjects: Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/ac35b9
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: A twist angle between two adjacent layers is a key approach to adjust the electronic characteristics of the van der Waals bilayer. The main goal of this study is to accurately predict the quasiparticle band structures and optical properties of bilayer MoS2 with different twist angles, 13.17°, 21.79°, 32.10°, and 60°) by using many-body perturbation G 0 W 0 theory and by solving the Bethe-Salpeter equation including excitonic effects on top of the partially G 0 W 0 calculation when spin-orbit coupling is included. Results of band structures and optical absorption spectrum show that the band gap and optical gap are sensitive to twist angle. Moreover, the twist angles and spin-orbit coupling can manipulate exciton binding energy. Our results also show that spin-orbit coupling and interlayer coupling (predominantly) induced spin splitting as large as 270 meV at the valence band of K point. This argument implies that twisted bilayer MoS2 is a powerful system for tuning the photoluminescence emission.