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arXiv · 2012.11492

Exciton-phonon coupling strength in single-layer MoSe2 at room temperature

Donghai Li·Chiara Trovatello·Stefano Dal Conte·Matthias Nuß·Giancarlo Soavi·Gang Wang·Andrea C. Ferrari·Giulio Cerullo·Tobias Brixner
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Abstract

Single-layer transition metal dichalcogenides are at the center of an ever increasing research effort both in terms of fundamental physics and applications. Exciton-phonon coupling plays a key role in determining the (opto)electronic properties of these materials. However, the exciton-phonon coupling strength has not been measured at room temperature. Here, we develop two-dimensional micro-spectroscopy to determine exciton-phonon coupling of single-layer MoSe2. We detect beating signals as a function of waiting time T, induced by the coupling between the A exciton and the A'1 optical phonon. Analysis of two-dimensional beating maps combined with simulations provides the exciton-phonon coupling. The Huang-Rhys factor of ~1 is larger than in most other inorganic semiconductor nanostructures. Our technique offers a unique tool to measure exciton-phonon coupling also in other heterogeneous semiconducting systems with a spatial resolution ~260 nm, and will provide design-relevant parameters for the development of optoelectronic devices.

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Donghai Li, Chiara Trovatello, Stefano Dal Conte, Matthias Nuß, Giancarlo Soavi, Gang Wang, Andrea C. Ferrari, Giulio Cerullo, Tobias Brixner. 2020-12-21. Exciton-phonon coupling strength in single-layer MoSe2 at room temperature. https://doi.org/10.1038/s41467-021-20895-0

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