Co-precipitation synthesis and luminescence behavior of Ce-doped yttrium aluminum garnet (YAG:Ce) phosphor: The effect of precipitant

YAG:Ce precursors were co-precipitated using ammonia water and ammonium hydrogen carbonate as precipitants, respectively. Phase transition of the precursors during sintering was compared between the two precipitants. The precursors synthesized with ammonia water transformed to YAG at about 1000°C via YAlO3 phase. The precursors synthesized with ammonium hydrogen carbonate directly converted to pure YAG at about 900°C. Comparing the powders produced with the two precipitants, the powders produced with ammonia hydrogen carbonate showed good dispersity. When sintered at 1600°C, aggregation of the powders synthesized with the two precipitants both became severe. With increase the sintering temperature, the maximum wavelength of excitation and emission spectra of the phosphors synthesized with ammonium water hardly varied. While the maximum wavelength of excitation spectra of the phosphors synthesized with ammonium hydrogen carbonate unchanged, and the emission spectra showed red shift. Because of size effect and higher loss of cerium content, the emission intensity of phosphors prepared with ammonium hydrogen carbonate was lower than the phosphors prepared with ammonium water, when sintered at the same temperature.