Quantum Size Effect And Energy Transfer In The System: Cds Nanoparticles And Tb(Iii) Ions In Oxide Xerogels

CdS nanoparticles have been prepared by a quaternary reverse micelle method. The size of the nanoparticles as controlled by changing the W(W=[H2O]/[CTAC]) molar ratio was in the quantum dot range. UV-Vis absorption and luminescence emission spectra of the CdS nanoparticles and materials consisting of the nanoparticles with Tb (III) ions incorporated into oxide xerogels show a quantum size effect. On other hand, for the materials there is observed an enhancement of emission intensity, owing to energy transfer from the excited CdS quantum dots to the emitting Tb(III). Additionally, a new effect, is described, namely the decreasing size of the CdS nanoparticles, that causes decrease of the emission intensity of Tb(III) ions and red shifting their bands.