Hybrid metal-organic nanocavity arrays for efficient light out-coupling

The spatially and spectrally resolved photoluminescence (PL) of the archetypical molecular dye ZnPc in periodically ordered organic-silver nanocavities (NC) is investigated by confocal microscopy. The presented approach of long-range ordered pillar structures prepared by nanosphere lithography not only combines the advantages of nanopatterning and localized surface plasmon resonances (LSPR) to improve the light out-coupling efficiency in metal-organic hybrid assemblies, but allows for distinction between geometrical and plasmonic contributions to the PL enhancement, the latter supported by complementary finite-difference-time-domain (FDTD) simulations. Supplementary time-resolved optical measurements indicate exciton lifetime reduction by at least one order of magnitude to be the main mechanism for PL increase amongst the improvement of geometrical out-coupling.