Room‐Temperature Observation of Near‐Intrinsic Exciton Linewidth in Monolayer WS2
Abstract
The homogeneous exciton linewidth, which captures the coherent quantum dynamics of an excitonic state, is a vital parameter in exploring light–matter interactions in 2D transition metal dichalcogenides (TMDs). An efficient control of the exciton linewidth is of great significance, and in particular of its intrinsic linewidth, which determines the minimum timescale for the coherent manipulation of excitons. However, such a control is rarely achieved in TMDs at room temperature (RT). While the intrinsic A exciton linewidth is down to 7 meV in monolayer WS2, the reported RT linewidth is typically a few tens of meV due to inevitable homogeneous and inhomogeneous broadening effects. Here, it is shown that a 7.18 meV near‐intrinsic linewidth can be observed at RT when monolayer WS2 is coupled with a moderate‐refractive‐index hydrogenated silicon nanosphere in water. By boosting the dynamic competition between exciton and trion decay channels in WS2 through the nanosphere‐supported Mie resonances, the coherent linewidth can be tuned from 35 down to 7.18 meV. Such modulation of exciton linewidth and its associated mechanism are robust even in presence of defects, easing the sample quality requirement and providing new opportunities for TMD‐based nanophotonics and optoelectronics.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 10, 2022
- Source ID
- 10.1002/adma.202108721
Entities
People
- Andrea Alù
- Brian Korgel
- Jie Fang
- Kan Yao
- Mauricio Terrones
- Mingsong Wang
- Suichu Huang
- Taizhi Jiang
- Tianyi Zhang
- Yuebing Zheng
Organizations
- Air Force Office of Scientific Research
- City University of New York
- Harbin Institute of Technology
- National Institutes of Health
- National Science Foundation
- Pennsylvania State University
- University of Texas at Austin