Luminescence studies on lanthanide ions (Eu3+, Dy3+ and Tb3+) doped YAG:Ce nano-phosphors

Yttrium aluminum garnet nanoparticles both undoped and doped with lanthanide ions (Ce3+, Eu3+, Dy3+ and Tb3+) having average size around 30 (+/- 3 nm) nm were prepared by glycine nitrate combustion method followed by annealing at a relatively low temperature of 800 degrees C. Increase in the annealing temperature has been found to improve the luminescence intensity and for 1200 degrees C heated samples there exists strong energy transfer from Tb3+ to Ce3+ ions in YAG:Ce(2%),Tb(2%) nanoparticles as revealed by luminescence studies. Co-doping the YAG:Ce nanoparticles with EU3+ results in significant decrease in the emission intensity of both Ce3+ and Eu3+ ions and this has been attributed to the oxidation of Ce3+ to Ce4+ and reduction of Eu3+ to EU2+ ions. Dy3+ co-doping did not have any effect on the Ce3+ emission as there is no energy transfer between Dy3+ and Ce3+ ions. (C) 2008 Elsevier B.V. All rights reserved.