1. Time-resolved ARPES Determination of a Quasi-Particle Band Gap and Hot Electron Dynamics in Monolayer MoS2
- Author
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Lee, Woojoo, Lin, Yi, Lu, Li-Syuan, Chueh, Wei-Chen, Liu, Mengke, Li, Xiaoqin, Chang, Wen-Hao, Kaindl, Robert A, and Shih, Chih-Kang
- Subjects
Physical Sciences ,Condensed Matter Physics ,Transition metal dichalcogenide ,MoS2 ,monolayer ,XUV-trARPES ,electronic structure ,exciton ,MSD-General ,MSD-Ultrafast MS ,Nanoscience & Nanotechnology - Abstract
The electronic structure and dynamics of 2D transition metal dichalcogenide (TMD) monolayers provide important underpinnings both for understanding the many-body physics of electronic quasi-particles and for applications in advanced optoelectronic devices. However, extensive experimental investigations of semiconducting monolayer TMDs have yielded inconsistent results for a key parameter, the quasi-particle band gap (QBG), even for measurements carried out on the same layer and substrate combination. Here, we employ sensitive time- and angle-resolved photoelectron spectroscopy (trARPES) for a high-quality large-area MoS2 monolayer to capture its momentum-resolved equilibrium and excited-state electronic structure in the weak-excitation limit. For monolayer MoS2 on graphite, we obtain QBG values of ≈2.10 eV at 80 K and of ≈2.03 eV at 300 K, results well-corroborated by the scanning tunneling spectroscopy (STS) measurements on the same material. more...
- Published
- 2021