Light-Emitting Plexciton: Exploiting Plasmon-Exciton Interaction in the Intermediate Coupling Regime.

Area of Science:

• Optics and Photonics
• Materials Science
• Condensed Matter Physics

Background:

• Plasmon-exciton interactions combine tunable plasmonics with light-emitting excitonic materials.
• Layered materials like WSe2 offer strong excitonic properties, while metal nanostructures provide tunable plasmons.

Purpose of the Study:

• To demonstrate light-emitting plexcitons from the coupling of monolayer WSe2 excitons and nanocavity plasmons.
• To investigate the enhancement of photoluminescence and understand the underlying coupling mechanisms.

Main Methods:

• Fabrication of a nanocube-over-mirror system to confine plasmons.
• Coupling monolayer WSe2 excitons with these confined nanocavity plasmons.
• Characterization using dark-field scattering spectroscopy and photoluminescence measurements.

Main Results:

• Observation of an anticrossing dispersion curve in the hybrid system.
• A significant 1700-fold enhancement in photoluminescence.
• Attribution of enhancement to increased local density of states in the intermediate coupling regime.

Conclusions:

• The study successfully demonstrates light-emitting plexcitons with significant photoluminescence enhancement.
• The compact system operates at room temperature, serving as a platform for quantum cavity electromagnetics.
• Confinement optimization via hot spot size reduction is crucial for enhanced light-matter interaction.