Zipfel, Jonas and Wagner, Koloman and Ziegler, Jonas D. and Taniguchi, Takashi and Watanabe, Kenji and Semina, Marina A. and Chernikov, Alexey (2020) Light-matter coupling and non-equilibrium dynamics of exchange-split trions in monolayer WS2. JOURNAL OF CHEMICAL PHYSICS, 153 (3): 034706. ISSN 0021-9606, 1089-7690
Full text not available from this repository. (Request a copy)Abstract
Monolayers of transition metal dichalcogenides present an intriguing platform to investigate the interplay of excitonic complexes in two-dimensional semiconductors. Here, we use optical spectroscopy to study the light-matter coupling and non-equilibrium relaxation dynamics of three-particle exciton states, commonly known as trions. We identify the consequences of the exchange interaction for the trion fine structure in tungsten-based monolayer materials from variational calculations and experimentally determine the resulting characteristic differences in their oscillator strength. It allows us to quantitatively extract trion populations from time-resolved photoluminescence measurements and monitor their dynamics after off-resonant optical injection. At liquid helium temperature, we observe a pronounced non-equilibrium distribution of the trions during their lifetime with comparatively slow equilibration that occurs on time-scales up to several hundreds of ps. In addition, we find an intriguing regime of population inversion at lowest excitation densities, which builds up and is maintained for tens of picoseconds. At a higher lattice temperature, the equilibrium is established more rapidly and the inversion disappears, highlighting the role of thermal activation for efficient scattering between exchange-split trions.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | NEGATIVELY CHARGED EXCITONS; SEMICONDUCTOR; PHOTOLUMINESCENCE; BIEXCITONS; MOS2; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics Physics > Institute of Experimental and Applied Physics > Junior Research Group Alexey Chernikov |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 18 Mar 2021 08:02 |
| Last Modified: | 18 Mar 2021 08:02 |
| URI: | https://pred.uni-regensburg.de/id/eprint/44183 |
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