Luminescence Emission Mediated by Surface Plasmon in the Semiconductor Quantum Dots

Abstract

The luminescence of the hybrid CdSe / ZnS QDs– Ag nanocrystals has a weak blue shift in comparison with the luminescence of the pure quantum dots (QDs). The luminescence of the CdSe / ZnS QDs only has a single exponential decay process, and the decay rates are almost same for different emission wavelengths. The luminescence of the hybrid CdSe / ZnS QDs– Ag nanocrystals structure has two decay processes: The first is a fast decay process, and then there is a slow decay process with nearly the same decay rate of the pure QDs. The fast decay process is due to the surface plasmon coupling and the coupling rate depends on the energy difference between the confined exciton in the QDs and the resonance energy of the Ag plasmon.