We investigate the impact of the dipole-active modes formed via the mode-mixing of the dipole mode with higher-order surface plasmon modes of a nanoegg on the radiative decay rate and quantum yield of an excited molecule near the nanoegg. The Purcell factor, rate of power dissipation by the emitter, and antenna efficiency of the nanoegg, as well as quantum yield enhancement of the emitter, were studied using the quasistatic approximation and the semiclassical theory of radiation, following the Gersten-Nitzan and Ford-Weber approaches.
Compared to the concentric nanoshell, we show that the dielectric core-metallic shell nanoegg is a more efficient plasmonic nanoantenna for radiative decay rate enhancement of single emitters. The quantum yield of the emitter was found to be more enhanced near the nanoshell, while its emission rate was found to be more enhanced near the nanoegg.