Synthesis of Agglomerate-Free YAG: Ce3+ Phosphors by Co-Precipitation and Low Temperature Spray Pyrolysis

摘要

Y3-xCexAl5012 (YAG: Ce34) phosphor particles were prepared by a new method called co-precipitation and low temperature spray pyrolysis (CP-LTSP) with oxalic acid and ammonia as precipitant. It corresponds to the first-step chemical liquid reaction, the second step dehydration and partial decomposition of precipitation droplets at 250 °C and then heating at 1100 ° C or above. Spherical as-prepared particles and agglomerate-free YAG: Ce3+ phosphor particles were obtained respectively. Pure YAG phase could be formed after LTSP at 250 °C and then annealing at 1100 °C for 4 h. The emission spectra and XRD patterns of YAG: Ce3+ phosphor particles indicated that the optimum doping concentration of Ce3+ was 0.06. The emission intensity increased with the increase of annealing temperature. As a result, the YAG: Ce3+ phosphor particles without optimization annealed at 1550 °C for 4 h had the similar emission intensity (96%) of the commercial phosphor by the solid-state method.