Formation mechanisms and morphology dependent luminescence properties of Y2O3:Eu phosphors prepared by spray pyrolysis process

Y2O3:Eu phosphors were prepared by a spray pyrolysis process followed by post annealing. Morphology control of Y2O3:Eu phosphor particles in the spray pyrolysis process was attempted by using citric acid (CA) and polyethylene glycol (PEG) as additives in the spray precursors. Three different morphologies of Y2O3:Eu phosphor particles, viz. smooth spheres, rods and flakes, were obtained in the presence of PEG with different molecular weights or without the presence of PEG, respectively. Possible mechanisms for the formation of Y2O3:Eu particles with the different morphologies have been proposed. It is shown that the spherical Y2O3:Eu phosphors have higher photoluminescent intensity than those with other morphologies.