We present a theoretical study on the radiative and nonradiative decay rates of an optical emitter in close proximity to a prolate-shaped metal nanoparticle. We use the model developed by Gersten and Nitzan [J. Chem. Phys. 75, 1139 (1981)] that we correct for radiative reaction and dynamic depolarization. Based on this analytical model, we provide physical insight on the optimization of anisotropic metal nanoparticles for plasmon-enhanced luminescence. We demonstrate that for properly engineered emitter-nanoparticle geometries, quantum-efficiency enhancements from an initial value of 1% (in the absence of the nanoparticle) to 70% are feasible. In addition, we show that for large (>100 nm) nanoparticles, the influence of Ohmic losses on plasmon-enhanced luminescence is substantially reduced, which implies that, if prolate shaped, even lossy metals such as Al and Cu are suitable materials for optical nanoantennas.

J. Appl. Phys.
Photonic Materials

Mertens, H, & Polman, A. (2009). Strong luminescence quantum-efficiency enhancement near prolate metal nanoparticles: Dipolar versus higher-order modes. J. Appl. Phys., 105(Article number: 44302), 1–8. doi:10.1063/1.3078108