Optical Coupling Of Core-shell Quantum Dots To Size-selected Gold Clusters

摘要

We have investigated the optical properties of CdSe/ZnS core-shell quantum dots (QDs), perturbed by the presence of a patterned film of size-selected gold nanoclusters. Quenching of the fluorescence emission of the quantum emitters was observed as a function of the distance between the metal nanoparticles and the QDs. Long-range quenching was observed up to distances of ～100 nm, which we attribute to a field-enhancement effect caused by the small size-selected clusters (<8 nm in diameter). This effect is weak relative to the dielectric damping caused by the electron-hole pair excitation in the clusters. We present experimental results that show agreement with a bulk-dielectric model implying that quantum confinement effects do not appear even at a cluster diameter of only ～8 nm.