Localized exciton modes and high quantum efficiency of a quantum emitter close to a MoS2 nanodisk

Abstract

The total and radiative spontaneous emission (SE) rates of a quantum emitter (QE) are enhanced several orders of magnitudes in the presence of a ${\mathrm{MoS}}_{2}$ nanodisk, compared to their free space value, by exciting localized exciton polariton modes. The quantum efficiency can reach values above $24%$, at emission energies where the dipole resonance is excited, for small values of the material damping parameters. The radiative emission rate is enhanced 565 times compared to its free-space value. Two set of sharp resonances of the SE rate emerge, which are connected with the excitation of the exciton energies of the ${\mathrm{MoS}}_{2}$ nanodisk. When the emission energy is in the halo, between the first two peaks of the normalized SE rate, the quantum efficiency has its largest value of $53%$, where the radiative emission is enhanced 4.3 times compared to the free-space value. The high values for the quantum efficiency are sustained over distances up to $40\phantom{\rule{0.16em}{0ex}}\text{nm}$, where the radiative spontaneous emission can compete with the nonradiative emission.