Fabrication, structural, and spectroscopic investigation of Tb-doped Lu₃Al₅ O₁₂ phosphor

A simple solution combustion synthesis technique was explored to produce Tb³⁺-doped Lu₃Al₅O₁₂ (LuAG:Tb) phosphor with particle size in the range from about 25 to 900 nm by using glycine, urea, and the mixture of them as fuels. The effects of processing parameters such as type of fuel, fuel-to-oxidizer ratio and the composition of the complex fuel were studied. An increase in phosphor brightness and a decrease in crystallization temperature with increasing urea content in the fuel were observed. The integrated emission intensity ratio of the ⁵D₃-⁷F_j transition to the ⁵D₄-⁷F_j transition as a function of Tb concentration in LuAG was also investigated. It is very interesting that the growth process of the particles exhibited two steps when the content of urea in the complex fuel increased from 0 to 1.0. By tailoring the glycine-to-urea ratio in the fuel, an excellent fuel was found and high performance phosphors were obtained.