Identification of Exciton Complexes in Charge-Tunable Janus W<sub>Se</sub><sup>S</sup> Monolayers

Matthew S. G. Feuer; Alejandro R.-P. Montblanch; Mohammed Y. Sayyad; Carola M. Purser; Ying Qin; Evgeny M. Alexeev; Alisson R. Cadore; Barbara L. T. Rosa; James Kerfoot; Elaheh Mostaani; Radosław Kalȩba; Pranvera Kolari; Jan Kopaczek; Kenji Watanabe; Takashi Taniguchi; Andrea C. Ferrari; Dhiren M. Kara; Sefaattin Tongay; Mete Atatüre

doi:10.1021/acsnano.2c10697

Journal article Identification of Exciton Complexes in Charge-Tunable Janus W_Se^S Monolayers

; ; ; ; ; ; ; ; ; ; ; ; ;

;

; ; ; ;

Download file (3.29 MB)
Download as zip (2.88 MB)

Collection

Citation

Matthew S. G. Feuer, Alejandro R.-P. Montblanch, Mohammed Y. Sayyad, Carola M. Purser, Ying Qin, Evgeny M. Alexeev, Alisson R. Cadore, Barbara L. T. Rosa, James Kerfoot, Elaheh Mostaani, Radosław Kalȩba, Pranvera Kolari, Jan Kopaczek, Kenji Watanabe, Takashi Taniguchi, Andrea C. Ferrari, Dhiren M. Kara, Sefaattin Tongay, Mete Atatüre. Identification of Exciton Complexes in Charge-Tunable Janus W_Se^S Monolayers. ACS Nano. 2023, 17 (8), 7326-7334. https://doi.org/10.1021/acsnano.2c10697

(BibTeX)

Description:

(abstract)

Janus transition-metal dichalcogenide mono-layers are fully artificial materials, where one plane of chalcogen atoms is replaced by chalco- gen atoms of a different type. Theory pre- dicts an in-built out-of-plane electric field, giving rise to long-lived, dipolar excitons, while preserv- ing direct-bandgap optical transitions in a uni- form potential landscape. Previous Janus studies had broad photoluminescence (>15 meV) spectra obfuscating their excitonic origin. Here, we identify the neutral, and negatively charged inter- and intravalley exciton transitions in Janus WSe monolayer with ∼6 meV optical linewidths. We combine a recently developed synthesis technique , with the integration of Janus monolayers into vertical heterostructures, allowing doping control. Further, magneto-optic measurements indicate that monolayer WSe has a direct bandgap at the K points. This work provides the foundation for applications such as nanoscale sensing, which relies on resolving excitonic energy shifts, and photo-voltaic energy harvesting, which requires efficient creation of long-lived excitons and integra- tion into vertical heterostructures.

Rights: