LaPO₄:Tb phosphor powders prepared by spray pyrolysis using two different spray generators

Abstract

LaPO4:Tb phosphor powders with a spherical shape and fine size were prepared by the filter expansion aerosol generator (FEAG) and ultrasonic spray pyrolysis processes. The mean size of the phosphor powders prepared by the FEAG process increased from 0.57 to 0.81 μm when the concentration of the spray solution was changed from 0.3 to 1M. On the other hand, the mean size of the phosphor powders prepared by the ultrasonic spray pyrolysis process increased from 0.82 to 1.16 μm when the concentration of the spray solution was changed from 0.3 to 1M. The phosphor powders had a pure monoclinic LaPO4 phase after post-treatment at a temperature of 1050 oC irrespective of the type of the spray generator and the concentrations of the spray solution. The photoluminescence intensities of the LaPO4:Tb phosphor powders prepared by the FEAG and ultrasonic spray pyrolysis processes increased with increasing the concentration of the spray solution. The LaPO4:Tb phosphor powders prepared by the FEAG process had lower photoluminescence intensities than those of the phosphor powders prepared by the ultrasonic spray pyrolysis process.