Luminescence of nanocrystalline Tb₃Al₅O₁₂: Ce³⁺ phosphors synthesized by nitrate-citrate gel combustion method

Ce³⁺-doped nanocrystalline terbium aluminum garnet (Tb ₃Al₅O₁₂: Ce³⁺, TAG:Ce³⁺) phosphors were successfully synthesized in low temperature by nitrate-citrate gel combustion method using microwave irradiation as a heating source. The pure TAG phase was obtained after calcining at 800°C for 6 h. The prepared nanocrystalline phosphors showed a broad peak at 551 nm, and the maximum doping concentration of Ce3+ for the highest emission intensity was 0.8 mol % at 551 nm. The temperature dependence on photoluminescence properties of the prepared TAG: Ce³⁺ phosphors was investigated from 25 to 275°C, and the activation energies (ΔE) for thermal quenching was determined by Arrhenius fitting. The experimental results clearly indicate that prepared nanocryatalline TAG: Ce³⁺ has great potentials for a down-conversion yellow phosphor in white light emitting diodes.