Effects Of Surface Plasmon Excitations On Photoluminescence By CdSe/Zns Quantum Dots

Abstract

The influence of localized surface plasmons (LSPs) and surface plasmon polaritons (SPPs) on the photoluminescence (PL) spectra of core/shell type CdSe/ZnS quantum dots (QDs) has been studied. Thin film samples of these QDs were deposited on glass slides, irradiated by 514 nm polarized beam from an Argon-ion laser, and PL spectra were measured using a high-resolution 1250M JY-Horiba spectrometer equipped with liquid-nitrogen cooled CCD detector. In the first set of experiments, PL spectra were measured on QDs and QDs-Au NPs mixture as a functions of the intensity of the 514 nm laser beam. In the second set of experiments, PL spectra were measured by using Kretschmann geometry, in which the SPPs were excited by p-polarized 514 nm laser beam incident upon a high-index prism coated with a 35 nm Au film. The films of QDs were deposited over the Au film by dissolving them in chloroform. Modified arrangement for Kretschmann configuration has been used and its advantages over other conventional arrangements have been discussed.