Nb impurity-bound excitons as quantum emitters in monolayer WS2
Point defects in crystalline solids behave as optically addressable individual quantum systems when present in sufficiently low concentrations. In two-dimensional (2D) semiconductors, such quantum defects hold potential as versatile single photon sources. Here, we report the synthesis and optical properties of Nb-doped monolayer WS<sub>2</sub> in the dilute limit where the average spacing between individual dopants exceeds the optical diffraction limit, allowing the emission spectrum to be studied at the single-dopant level. We show that these individual dopants exhibit common features of quantum emitters, including narrow emission lines (with linewidths <1 meV), strong spatial confinement, and photon antibunching. These emitters consistently occur within a narrow spectral range across multiple samples, distinct from common quantum emitters in van der Waals (vdW) materials that show large ensemble broadening. Analysis of the Zeeman splitting reveals that they can be attributed to bound exciton complexes comprising dark excitons and negatively charged Nb.
Authors
- Paul J. Pigram (ORCID: https://orcid.org/0000-0002-7972-492X)
- See Yoong Wong (ORCID: https://orcid.org/0000-0002-1491-8838)
- Fengyuan Xuan (ORCID: https://orcid.org/0000-0002-0624-882X)
- Michel Bosman (ORCID: https://orcid.org/0000-0002-8717-7655)
- Takashi Taniguchi (ORCID: https://orcid.org/0000-0002-1467-3105)
- Yi Wei Ho (ORCID: https://orcid.org/0000-0002-5487-4948)
- Su Ying Quek (ORCID: https://orcid.org/0000-0003-4223-2953)
- Kenji Watanabe (ORCID: https://orcid.org/0000-0003-3701-8119)
- Goki Eda (ORCID: https://orcid.org/0000-0002-1575-8020)
- Andrés Granados del Águila (ORCID: https://orcid.org/0000-0002-8162-7192)
- Jingda Zhang (ORCID: https://orcid.org/0009-0009-8798-9619)
- Leyi Loh (ORCID: https://orcid.org/0000-0002-6315-7545)
- Maciej Koperski (ORCID: https://orcid.org/0000-0002-8301-914X)
- Yuan Chen (ORCID: https://orcid.org/0009-0009-0835-3680)
- Zhe Wang (ORCID: https://orcid.org/0000-0001-6485-1523)
Institutions
- National University of Singapore (SG)
- La Trobe University (AU)
- National Institute for Materials Science (JP)
Publication Details
- Journal
- Nature Communications
- Published
- 2024-11-19
- DOI
- https://doi.org/10.1038/s41467-024-54360-5
- Citations
- 12
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 1.41
Funders
- Australian National Fabrication Facility
- La Trobe University
- National Research Foundation
- National University of Singapore
- National Research Foundation Singapore
- Ministry of Education - Singapore
- Narodowym Centrum Nauki
- Ministry of Education, India
- National Supercomputing Centre Singapore
- Japan Society for the Promotion of Science
- Office of Naval Research
- Office of Naval Research Global