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Furthermore, the reduction in the measured lifetime of the first excited electronic state from 20 ns for the QDs deposited directly on the quartz substrate to 7 ns for the QDs casted on the gold film, gives a further evidence of the surface plasmons effect in the (PL) of the CdSe-ZnS QDs. This surface plasmons effect facilitated the appearance of these mentioned bands in more intensive features than the corresponding traditional weak absorption bands. The detected surface plasmons effect in QDs enhances the intensity of the fluorescence bands. This scheme was confirmed by the recent theoretical prediction using the state-of-the art time domain ab initio density functional theory and the atomistic pseudopotential calculations. A scheme based on multiple exciton generation (MEG) for the appearance of the fluorescence bands was proposed.

They were detected for the first time and assigned according to the theoretical predictions of excitons in a spherical potential with Coulomb interactions and valence bands mixing. Fast and highly efficient oxidation reactions of ALA to produce the hydroxyl radicals (HO) and of GLU to produce the superoxide anion (O2. These bands are more intense and resolved than the corresponding traditional weak absorption bands. In this present work, CdSe/ZnS core/shell quantum dots (QDs) were exploited in the oxidation reactions of 5-aminolevulinic acid (ALA) and glutamate (GLU) for the production of reactive oxygen species (ROS). Excitation with a wavelength of 400 nm reveals a structure fluorescence spectrum which consists of five distinct bands. The samples were optically arranged and pumped by different wavelengths, and the PL spectra were detected. The QDs were casted on half-coated quartz substrates with 50 nm of gold and prepared for studying the surface plasmons effect. The QDs were casted on half-coated quartz substrates with 50 nm of gold and prepared for studying the surface plasmons effect. Absorption and photoluminescence (PL) spectra of a colloidal CdSe-ZnS core-shell quantum dots (QDs) were measured within the strong confinement regime.

Absorption and photoluminescence (PL) spectra of a colloidal CdSe-ZnS core-shell quantum dots (QDs) were measured within the strong confinement regime.