RECOMBINATION LUMINESCENCE QUENCHING OF NONSTOICHIOMETRIC CDS CLUSTERS BY TRIVALENT LANTHANIDE IONS

The recombination luminescence of CdS clusters characterized by different particle size distributions, based on E(g) values, and different stoichiometries is quenched to a different extent by Ln3+/Ln2+ ions. Electron acceptors with redox potentials less negative than that of CdS (e(CB)-) quench the recombination luminescence of CdS effectively. However, if the redox potential of the acceptor differs greatly from that of CdS, larger CdS clusters are quenched more effectively than smaller ones leading to blue-shifted recombination luminescence. Preliminary results indicate that the electron transfer process depends upon the extent of nonstoichiometry in the cluster.