(YGd)BO₃:Eu phosphor particles prepared from the solution of polymeric precursors by spray pyrolysis

(YGd)BO₃:Eu phosphor particles with spherical-like shape and fine size were prepared by posttreatment of as-prepared particles by spray pyrolysis. In order to improve the morphological characteristics of (YGd)BO₃:Eu phosphor particles, the key concept used in this work is the introduction of the esterification reaction between citric acid and ethylene glycol inside liquid droplets. (YGd)BO₃:Eu phosphor particles prepared by spray pyrolysis from an aqueous solution exhibited an irregular shape and broad size distribution after posttreatment. On the other hand, the as-prepared particles by spray pyrolysis from the solution with polymeric precursors became (YGd)BO₃:Eu phosphor particles with spherical-like shape, micron size and narrow size distribution after posttreatment. In the case of polymeric precursor solution, the particles with regular shape and fine size were obtained by the reformation and recrystallization process during posttreatment of as-prepared particles. The mean size of (YGd)BO₃:Eu phosphor particles prepared from polymeric precursors solution was 1.1 μm after posttreatment at 1075°C for 3 h. The photoluminescence intensities of the particles prepared from the solution with and without polymeric precursors were similar to that of the commercial product.