Photoluminescence plasmonic enhancement of single quantum dots coupled to gold microplates

Optical properties of quantum dots can be drastically changed by surface plasmons excited in neighboring metallic nanostructures. Here we investigated the photoluminescence enhancement dependence of single quantum dots on the separation distance with Au microplates by a single particle spectroscopy. The quantum dot-Au microplate hybrid structures provided a photoluminescence enhancement of up to ∼16-fold when the separation distance between the surface of Au microplate and the center of QD was 18 ± 1.9 nm. Accordingly, the lifetime of those quantum dots was shortened compared with the ones on glass plates directly. Theoretical simulation revealed that the variation of photoluminescence enhancement was closely dependent on the separation distance between the QD and the Au microplate, in good agreement with the experimental results.