Terbium-doped lanthanum phosphate phosphor particles with a submicrometre size and spherical shape

Submicrometre-sized LaPO4Tb phosphor particles with a spherical shape and filled morphology were prepared by spray pyrolysis from a polymeric precursor solution containing citric acid and ethylene glycol. The LaPO4Tb phosphor particles obtained from the aqueous spray solution had a hollow morphology and large size because of the high drying and decomposition rates of droplets. The mean sizes of the particles obtained from the aqueous spray and polymeric precursor solutions were each 1 and 0.8 mu m, respectively. The optimum post-treatment temperature for the preparation of LaPO4Tb phosphor particles with a spherical shape and high brightness was 1100 degrees C. The prepared LaPO4Tb phosphor particles had high photoluminescence intensities under vacuum ultraviolet illumination of 147 nm.