Photoluminescence properties of Ce1-xTbxMgAl11O19 phosphor particles prepared by spray pyrolysis

Spray pyrolysis method was applied to the preparation of submicron Ce1-xTbxMgAl11O19 phosphor particles. The characteristics such as photoluminescence, crystallinity, and morphology were investigated under various preparation conditions. While the as-prepared particles by spl ay pyrolysis at temperature of 900 degrees C had amorphous phase, the particles calcined above 1400 degrees C had phase-pure magnetoplumbite structure, and its crystallinity increased with increasing the calcining temperature. The as-prepared particles had spherical morphology, submicron size, and narrow size distribution. The mean size of the particles increased fi-om 0.5 to 1.4 mu m when the spray solution concentration increased from 0.03 to 1.5 M. After calcination; the particles showed 545 nm green emission characteristic of Tb3+ ions with optimum excitation at 280 nm. The maximum luminous intensity was obtained at x = 0.4. The optimum calcining temperature for good brightness was 1500 degrees C. Particles directly prepared by spray pyrolysis at 1500 degrees C show good green emission characteristics and maintain its sphericity and non-aggregation characteristics.