Figure 1
From: Nanocavity-induced trion emission from atomically thin WSe2
Monolayer WSe2 embedded in a plasmonic nanocavity and characterizations. (a) Schematic of monolayer WSe2 embedded in a plasmonic nanocavity comprising gold nanoparticles (AuNPs) and gold-film substrate, with enhanced PL emission being observed. (b) Representative scanning electron microscope (SEM) image of monolayer WSe2 embedded in nanocavity (WSe2/Nanocavity). (c) PL spectra of monolayer WSe2 in nanocavity and monolayer WSe2 on sapphire with an emission peak at 1.67Â eV and 1.62Â eV, respectively. (d) Reflectance spectra of nanocavity with and without monolayer WSe2. The red dot at 1.68Â eV denotes the energy of localized plasmon resonance. (e) Finite-difference time-domain (FDTD) simulation of the enhanced electric displacement intensity, |Ez|2, inside the monolayer WSe2 due to the localized vertical gap plasmons.
