Luminescence studies on lanthanide ions (Eu 3+, Dy 3+ and Tb 3+) doped YAG:Ce nano-phosphors

Abstract

Yttrium aluminum garnet nanoparticles both undoped and doped with lanthanide ions (Ce 3+, Eu 3+, Dy 3+ and Tb 3+) 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 °C. Increase in the annealing temperature has been found to improve the luminescence intensity and for 1200 °C heated samples there exists strong energy transfer from Tb 3+ to Ce 3+ ions in YAG:Ce(2%),Tb(2%) nanoparticles as revealed by luminescence studies. Co-doping the YAG:Ce nanoparticles with Eu 3+ results in significant decrease in the emission intensity of both Ce 3+ and Eu 3+ ions and this has been attributed to the oxidation of Ce 3+ to Ce 4+ and reduction of Eu 3+ to Eu 2+ ions. Dy 3+ co-doping did not have any effect on the Ce 3+ emission as there is no energy transfer between Dy 3+ and Ce 3+ ions.