Fig. 1: Hybrid 2D semiconductor–dielectric nanoantennas for enhanced light–matter coupling regime in 2D TMDCs.
From: Radiative suppression of exciton–exciton annihilation in a two-dimensional semiconductor
a Simulated scattering cross-section of a GaP nanoantenna with a radius of 90 nm and height of 100 nm (dashed black line), and absorption of the 1s-exciton state of a WS2 monolayer on SiO2 substrate (red line). The scattering cross-section is analyzed with a multipolar expansion, where the respective weights of the electrical (p) and magnetic (m) dipoles, and the electrical (qE) and magnetic (qM) quadrupoles are shown. b Electron microscope image of a fabricated GaP nanoantenna. Scale bar 100 nm. c FDTD simulated electric field intensity, \({(| E| /| {E}_{0}| )}^{2}\), at the top surface of a GaP nanoantenna (r = 90 nm, h = 100 nm) at λ = 620 nm. Scale bar 100 nm. d Dark field scattering spectra of fabricated GaP nanoantennas for different radial dimensions. The dashed red line at 620 nm represents the resonance wavelength of WS2 monolayer excitons. e Illustration of the hybrid nanophotonic system composed of a WS2 monolayer coupled to a cylindrical GaP dielectric nanoantenna. f PL of nanoantenna coupled WS2 (in red) and dark field scattering (in light blue) of the GaP nanoantennas (radius 90 nm, height 100 nm). The scattering spectra is fitted with a coupled oscillator model (COM — dashed black line). g Upper panel: coupling strength (g) values extracted from the coupled oscillator model used to fit the scattering spectra of nanoantennas coupled with WS2 monolayers. Lower panel: ratio of the extracted coupling strengths values compared with the normalized strong coupling condition 4g/(γX + γD) = 1
