Download file (2.24 MB)
Download as zip (1.91 MB)

Collection

Citation

Description:

Monolayer transition metal dichalcogenides (TMDs) have emerged as highly promising candidates for optoelectronic applications due to their direct band gap and strong light-matter interactions. However, exfoliated TMDs have demonstrated optical characteristics that fall short of expectations, primarily because of significant defects and associated doping in the synthesized TMD crystals. Here, we report improvement of optical properties in monolayer TMDs of MoS2, MoSe2, WS2, and WSe2, by hBN-encapsulation annealing. Monolayer WSe2 showed 2,000 % enhancement of photoluminescence quantum yield (PLQY) and 1,000 % increase of prolonged lifetime after encapsulation annealing at 1000°C, which are attributed to dominant radiative recombination of excitons through dedoping of exfoliated monolayer TMDs. Furthermore, after encapsulation annealing, the transport characteristics of monolayer WS2 ¬changed from n-type to ambipolar, along with an enhanced hole transport, which also support dedoping of annealed TMDs. This work provides an innovative approach to elevate the optical grade of monolayer TMDs, enabling the fabrication of high-performance optoelectronic devices.

Rights:

• https://creativecommons.org/licenses/by-nc/3.0/legalcode
  

Keyword: Monolayer TMDs, optical properties, hBN-encapsulation

Date published: 2024-02-26

Publisher: Royal Society of Chemistry (RSC)

Journal:

• Nanoscale (ISSN: 20403372) vol. 16 issue. 11 p. 5836-5844

Funding:

• National Research Foundation of Korea NRF-2021R1A2C301431613
• National Research Foundation of Korea NRF-2019R1A2C3006189
• National Research Foundation of Korea NRF-2017R1A5A1014862
• Seoul National University
• Japan Society for the Promotion of Science 21H05233
• Japan Society for the Promotion of Science 23H02052
• Ministry of Education, Culture, Sports, Science and Technology
• Ministry of Science and ICT 2017R1A5A1014862
• Ministry of Science and ICT 2019R1A2C3006189
• Ministry of Science and ICT 2021R1A2C301431613

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1039/d3nr06641j

Related item:

Other identifier(s):

Contact agent:

Updated at: 2025-02-15 12:30:34 +0900

Published on MDR: 2025-02-15 12:30:34 +0900