Chemically binding Eu3+ onto CdS semiconductor nanoparticle surface

Europium ions were chemically bound to CdS nanoparticles surface by diethylenetri-aminepentaacetate (DTPA, 1) in a two-step synthetic route. First 1 was applied to chelate with cadmium on the surface of cadmium-rich CdS nanoparticles and act as a capping agent. Further, the purified 1-capped particles were used to bind with Eu3+. The purified and redispersed particles were characterized by photoluminescence spectroscopy, TEM and SEM. It was observed that Eu3+ on the nanoparticle surface significantly increased the band gap emission and decreased the surface emission intensity of the CdS nanoparticles.