Electroluminescence as a probe of strong exciton-plasmon coupling in few-layer WSe2

TL;DR

This study demonstrates how electroluminescence can be used to probe and analyze strong exciton-plasmon coupling in few-layer WSe2, revealing plexciton polaritons with potential for tunable photonic devices.

Contribution

It introduces a novel electroluminescence-based method to investigate strong exciton-plasmon coupling in 2D materials, supported by electromagnetic simulations.

Findings

Rabi splittings exceeding 50 meV observed in strong coupling regime

Electroluminescence spectra reveal plexciton polaritons and their polarization characteristics

Potential for engineering tunable photonic devices using plexciton coupling

Abstract

The manipulation of coupled quantum excitations is of fundamental importance in realizing novel photonic and optoelectronic devices. We use electroluminescence to probe plasmon-exciton coupling in hybrid structures consisting of a nanoscale plasmonic tunnel junction and few-layer two-dimensional transition-metal dichalcogenide transferred onto the junction. The resulting hybrid states act as a novel dielectric environment that affects the radiative recombination of hot carriers in the plasmonic nanostructure. We determine the plexcitonic spectrum from the electroluminescence and find Rabi splittings exceeding 50 meV in strong coupling regime. Our experimental findings are supported by electromagnetic simulations that enable us to explore systematically, and in detail, the emergence of plexciton polaritons as well as the polarization characteristics of their far-field emission. Electroluminescence modulated by plexciton coupling provides potential applications for engineering compact photonic devices with tunable optical and electrical properties.