Preparation and properties of Pr3+/Ce3+:YAG phosphors using triethanolamine as dispersant and pH regulator

Pr³⁺/Ce³⁺:YAG precursors were co-precipitated using triethanolamine as dispersant and pH regulator. The different dosages of triethanolamine (D) vs. the properties of Pr³⁺/Ce³⁺:YAG phosphors were discussed. When D = 0.5 vol%, the pH of titration process was controlled in the range of ～7.94–8.16 to guarantee the uniform distribution of Al, Y, Ce and Pr in the precursors. The relatively higher pH could decrease the loss of Ce and Pr in the precursors and increase the particle size of the obtained powders, which was beneficial to the enhancement of luminescent intensity. Therefore, the precursors directly converted to pure-phase YAG at 900°C, and the phosphors calcined at 1000°C showed the best dispersity due to the dispersion effect of triethanolamine and the most excellent luminescent property. When D ≥ 2 vol%, although pure-phase YAG was detected, the emission intensity of the phosphors decreased due to the decrease of dispersity and purity. Moreover, the co-doped Pr³⁺ enhanced the red emission of Pr³⁺/Ce³⁺:YAG phosphors.