Radiative rate enhancements in ensembles of hybrid metal-semiconductor nanostructures.

We report on radiative decay rate modifications of dipole emitters in the proximity of anisotropic metal nanostructures. Using time, angle, and polarization resolved photoluminescence spectroscopy, we show that resonant interactions between surface plasmons in gold nanodisks and excitons in semiconductor nanocrystals require both spectral and orientational overlap resulting in radiative rate enhancements with directional characteristics. Numerical simulations of emission decay dynamics based on local electric field enhancements are in excellent agreement with experimental results.