Drift-dominant exciton funneling and trion conversion in 2D semiconductors on the nanogap
SCIE
SCOPUS
- Title
- Drift-dominant exciton funneling and trion conversion in 2D semiconductors on the nanogap
- Authors
- Lee, Hyeongwoo; Koo, Yeonjeong; Choi, Jinseong; Kumar, Shailabh; Lee, Hyoung-Taek; Ji, Gangseon; Choi, Soo Ho; Kang, Mingu; Kim, Ki Kang; Park, Hyeong-Ryeol; Choo, Hyuck; Park, Kyoung-Duck
- Date Issued
- 2022-02
- Publisher
- American Association for the Advancement of Science
- Abstract
-
Understanding and controlling the nanoscale transport of excitonic quasiparticles in atomically thin two-dimensional (2D) semiconductors are crucial to produce highly efficient nano-excitonic devices. Here, we present a nanogap device to selectively confine excitons or trions of 2D transition metal dichalcogenides at the nanoscale, facilitated by the drift-dominant exciton funneling into the strain-induced local spot. We investigate the spatiospectral characteristics of the funneled excitons in a WSe
2
monolayer (ML) and converted trions in a MoS
2
ML using hyperspectral tip-enhanced photoluminescence imaging with <15-nm spatial resolution. In addition, we dynamically control the exciton funneling and trion conversion rate by the gigapascal-scale tip pressure engineering. Through a drift-diffusion model, we confirm an exciton funneling efficiency of ∼25% with a significantly low strain threshold (∼0.1%), which sufficiently exceeds the efficiency of ∼3% in previous studies. This work provides a previously unexplored strategy to facilitate efficient exciton transport and trion conversion of 2D semiconductor devices.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/114690
- DOI
- 10.1126/sciadv.abm5236
- ISSN
- 2375-2548
- Article Type
- Article
- Citation
- Science Advances, vol. 8, no. 5, 2022-02
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- There are no files associated with this item.
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