Effects of flux additives on the characteristics of Y2.95Al5O12:0.05Ce3+ phosphor: Particle growth mechanism and luminescence

The dependence of the amount of the BaF2 flux additive on the luminescence of Y2.95Al5O12:0.05Ce3+ phosphors was investigated. The integrated emission intensity of Y2.95Al5O12:0.05Ce3+ prepared without the flux was enhanced by 29% with the addition of BaF2 flux at the optimum amount of 6 wt. %. Such an enhancement can be attributed to the purer phase of Y3Al5O12 and the morphology change from the irregular shape to spherical shape with the smoother surface due to the flux. The morphology and luminescence of Y2.95Al5O12:0.05Ce3+ prepared with the 6 wt. % BaF2 flux additive (Sample II) were further compared with those of Y2.95Al5O12:0.05Ce3+ prepared with the 7 wt. % H3BO3 flux additive (Sample I). The particle size, particle shape, and integrated emission intensity (λex = 450 nm) of the former were found to be larger, more regular, and 6% higher than those of the latter. The difference in the morphology of Samples I and II, which led to the difference in the emission intensity and the external quantum efficiency, were well explained by the particle growth mechanism.