Ce-doped YAG phosphor powders prepared by co-precipitation and heterogeneous precipitation

Ce-doped YAG phosphor powders were prepared by co-precipitation and heterogeneous precipitation methods using ammonium hydrogen carbonate as precipitant. Pure Ce-doped YAG phase was obtained by calcining the precipitate at 1200degreesC. The emission intensity of Ce-doped YAG phosphor was found to increase with increases in the calcining temperature, and there was a clear shift of peaks to longer wavelengths. The emission intensity of two samples was compared. It was found that, calcining below 1340degreesC, the emission intensity of sample prepared by co-precipitation was higher, on the other hand, calcining above 1340degreesC, the emission intensity of sample prepared by heterogeneous precipitation was higher. (C) 2003 Elsevier B.V. All rights reserved.