Effects of BaF2 flux on the properties of yellow-light-emitting terbium aluminum garnet phosphor powders prepared by spray pyrolysis

Spherical-like Tb3Al5O12:Ce (TAG:Ce) phosphor powders with good photoluminescence intensities were prepared by spray pyrolysis from a spray solution containing BaF2 flux. The phosphor powders prepared from the spray solution without the BaF2 flux had irregular morphologies and aggregated structure. On the other hand, the phosphor powders obtained from the spray solution containing a high amount of BaF2 flux were spherical-like shapes, narrow size distributions and non-aggregation. All the powders comprised single-phase body-centered cubic Tb3Al5O12 (TAG), irrespective of the addition amount of the BaF2 flux. The maximum photoluminescence intensity of the TAG:Ce phosphor powders obtained from spray solutions containing BaF2 was 140% that of the phosphor powders obtained from the spray solution without the flux material. The mean size of the TAG:Ce phosphor powders prepared from the spray solution containing 9 wt.% BaF2 with respect to the phosphor was 1.02 μm after post-treatment at 1450 °C.