Abstract
Exciton emitters in two-dimensional monolayer transition-metal dichalcogenides (TMDs) provide a boulevard for the emerging optoelectronic field, ranging from miniaturized light-emitting diodes to quantum emitters and optical communications. However, the low quantum efficiency from limited light-matter interactions and harmful substrate effects seriously hinders their applications. In this work, we achieve a ∼438-fold exciton photoluminescence enhancement by constructing a Fabry-Pérot cavity consisting of monolayer WS2 and a micron-scale hole on the SiO2/Si substrate. The overall enhancement results from the increased exciton-photon interaction due to the effective exciton-cavity mode coupling and decreased trion formation from the weakened substrate effect confirmed by transient spectroscopy. Moreover, the effective coupling improves the directivity of excitons’ spontaneous radiation (fwhm ∼ 5°). This research reveals a practical platform for simultaneously enhancing exciton emission and attenuating the substrate effect, and it provides a blueprint for the development of two-dimensional monolayer TMDs-based emitters in integrated optoelectronic devices.
| Original language | English |
|---|---|
| Pages (from-to) | 2639-2646 |
| Number of pages | 8 |
| Journal | Nano Letters |
| Volume | 25 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 19 Feb 2025 |
| Externally published | Yes |
Keywords
- Fabry−Pérot cavity
- PL enhancement
- monolayer WS
- substrate effect
- two-dimensional transition-metal dichalcogenides