Enhanced light-matter interaction in an atomically thin semiconductor coupled with dielectric nano-antennas

Area of Science:

• Materials Science
• Optics
• Condensed Matter Physics

Background:

• Atomically thin 2D semiconducting transition metal dichalcogenides possess unique optical properties suitable for coupling with photonic cavities.
• All-dielectric nano-cavities with reduced mode volumes and minimal non-radiative losses are a recent advancement.

Purpose of the Study:

• To realize low-loss, high-refractive-index dielectric gallium phosphide (GaP) nano-antennas coupled to 2D transition metal dichalcogenides (TMDs).
• To investigate the effects of this coupling on photoluminescence and Raman scattering signals.

Main Methods:

• Fabrication of GaP nano-antennas with small mode volumes.
• Coupling these nano-antennas to mono- and bilayers of tungsten diselenide (WSe2).
• Characterization of photoluminescence and Raman scattering enhancement.

Main Results:

• Observed photoluminescence enhancement exceeding 10x compared to WSe2 on planar GaP.
• Attributed enhancement to increased spontaneous emission rate, improved directionality, and efficient optical excitation.
• Reported photoluminescence polarization dependence and over 10x Raman scattering signal enhancement.

Conclusions:

• Dielectric nano-antennas, specifically GaP, offer a viable platform for enhancing light-matter interactions in 2D semiconductors.
• This approach enables precise engineering of optical properties for applications in nanophotonics and quantum technologies.