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

• Autor(a) principal: Epstein, Itai
• Data de Publicação: 2020
• Outros Autores: Terrés, Bernat, Chaves, André J., Pusapati, Varun-Varma, Rhodes, Daniel A., Frank, Bettina, Zimmermann, Valentin, Qin, Ying, Watanabe, Kenji, Taniguchi, Takashi, Giessen, Harald, Tongay, Sefaattin, Hone, James C., Peres, N. M. R., Koppens, Frank
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/66025
• topic: TMD Excitons; Unity absorption; 2D materials; Light-matter interaction; Exciton complexes; Science & Technology

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 ultralow 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, nonradiative 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.