Enhancement of QDs photoluminescence by localized surface plasmon effect of Au-NPs

Abstract

Photoluminescence enhancement of CdSe/CdS/ZnS QDs by localized surface plasmon resonance of large Au-NPs has been investigated. The photoluminescence of the QDs with an emission wavelength at 620 nm in a PMMA matrix is enhanced by immobilized Au-NPs. By considering the lifetime and excitation dependent photoluminescence we realized that the emission and excitation rate enhancements both contributed to the total photoluminescence enhancement. PL measurements were carried out for different sizes of Au-NPs to find out their influences on the emission of QDs. The largest enhancement is achieved by applying 80 nm Au-NPs. Silanization method gives us the opportunity easily to prepare samples with different concentrations of Au-NPs. It is revealed that increasing the concentration of the Au-NPs layer provides higher scattering cross section which contributes in PL enhancement