Control of trion-to-exciton conversion in monolayer WS₂ by orbital angular momentum of light
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1.
California Institute of Technology
Abstract
Controlling the density of exciton and trion quasiparticles in monolayer two-dimensional (2D) materials at room temperature by nondestructive techniques is highly desired for the development of future optoelectronic devices. Here, the effects of different orbital angular momentum (OAM) lights on monolayer tungsten disulfide at both room temperature and low temperatures are investigated, which reveal simultaneously enhanced exciton intensity and suppressed trion intensity in the photoluminescence spectra with increasing topological charge of the OAM light. In addition, the trion-to-exciton conversion efficiency is found to increase rapidly with the OAM light at low laser power and decrease with increasing power. Moreover, the trion binding energy and the concentration of unbound electrons are estimated, which shed light on how these quantities depend on OAM. A phenomenological model is proposed to account for the experimental data. These findings pave a way toward manipulating the exciton emission in 2D materials with OAM light for optoelectronic applications.
Additional Information
© 2022 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). Submitted 20 August 2021; Accepted 10 February 2022; Published 1 April 2022. We thank W.-H. Lin for developing the ML-WS₂ sample and useful discussions. This work was supported by the Ministry of Science and Technology, Taiwan under contract nos. MOST 109-2811-M-003-513, MOST 108-2112-M-003-010-MY3, and MOST 109-2112-M-003-002. N.-C.Y. acknowledges joint support by the National Science Foundation under the Physics Frontier Centers program for the Institute for Quantum Information and Matter (IQIM) at the California Institute of Technology (award #1733907) and the Army Research Office under the MURI program (award #W911NF-16-1-0472). Author contributions: The experiments were performed by R.K., K.B.S., T.-D.H., and Y.-F.C. The numerical calculation were completed by R.K., and Y.-F.C. provided assistance in performing the optical measurements. N.-C.Y., Y.-W.L., and T.-H.L. supervised this research. All authors have read and approved the manuscript. All authors discussed the results and commented on the manuscript. The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.Attached Files
Published - sciadv.abm0100.pdf
Supplemental Material - sciadv.abm0100_sm.pdf
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Additional details
- Alternative title
- Control of trion-to-exciton conversion in monolayer WS2 by orbital angular momentum of light
- Eprint ID
- 114275
- Resolver ID
- CaltechAUTHORS:20220413-746783000
- PMCID
- PMC10938575
- MOST 109-2811-M-003-513
- Ministry of Science and Technology (Taipei)
- MOST 108-2112-M-003-010-MY3
- Ministry of Science and Technology (Taipei)
- MOST 109-2112-M-003-002
- Ministry of Science and Technology (Taipei)
- Institute for Quantum Information and Matter (IQIM)
- PHY-1733907
- NSF
- W911NF-16-1-0472
- Army Research Office (ARO)
- Created
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2022-04-13Created from EPrint's datestamp field
- Updated
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2022-04-13Created from EPrint's last_modified field
- Caltech groups
- Institute for Quantum Information and Matter