Near-unity light absorption in a monolayer WS2 van der Waals heterostructure cavity

Excitons in monolayer transition-metal-dichalcogenides (TMDs) dominate their optical response and exhibit strong light-matter interactions with lifetime-limited emission. While various approaches have been applied to enhance light-exciton interactions in TMDs, the achieved strength have been far bel...

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Bibliographic Details
Published in:arXiv.org 2019-09
Main Authors: Epstein, Itai, Bernat Terrés, Chaves, André J, Varun-Varma Pusapati, Rhodes, Daniel A, Frank, Bettina, Zimmermann, Valentin, Qin, Ying, Watanabe, Kenji, Taniguchi, Takashi, Giessen, Harald, Tongay, Sefaattin, Hone, James C, Peres, Nuno M R, Koppens, Frank
Format: Article
Language:English
Subjects:
Decay rate
Electromagnetic absorption
Excitons
Heterostructures
Monolayers
Optoelectronic devices
Phase transitions
Transition metal compounds
Unity
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Summary:Excitons in monolayer transition-metal-dichalcogenides (TMDs) dominate their optical response and exhibit strong light-matter interactions with lifetime-limited emission. While various approaches have been applied to enhance light-exciton interactions in TMDs, the achieved strength have been far below unity, and a complete picture of its underlying physical mechanisms and fundamental limits has not been provided. Here, we introduce a TMD-based van der Waals heterostructure cavity that provides near-unity excitonic absorption, and emission of excitonic complexes that are observed at ultra-low excitation powers. Our results are in full agreement with a quantum theoretical framework introduced to describe the light-exciton-cavity interaction. We find that the subtle interplay between the radiative, non-radiative and dephasing decay rates plays a crucial role, and unveil a universal absorption law for excitons in 2D systems. This enhanced light-exciton interaction provides a platform for studying excitonic phase-transitions and quantum nonlinearities and enables new possibilities for 2D semiconductor-based optoelectronic devices.
ISSN:2331-8422
DOI:10.48550/arxiv.1908.07598