Localized exciton modes and high quantum efficiency of a quantum emitter close to a MoS2 nanodisk
AbstractThe total and radiative spontaneous emission (SE) rates of a quantum emitter (QE) are enhanced several orders of magnitudes in the presence of a MoS2 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 MoS2 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 40nm, where the radiative spontaneous emission can compete with the nonradiative emission.