Characteristics of Y₃Al₅O₁₂:Ce phosphor powders prepared by spray pyrolysis from ethylenediaminetetraacetic acid solution

Nanometer and submicron-sized YAG:Ce phosphor powders were prepared by spray pyrolysis from the spray solutions with ethylenediaminetetraacetic acid (EDTA). The precursor powders with hollow and thin wall structure turned to the fine-sized YAG:Ce phosphor powders after post-treatment at high temperatures of 1400 and 1500 °C. The mean size of the phosphor powders post-treated at a temperature of 1500 °C was 0.72 μm. The white LEDs formed from the YAG:Ce phosphor powders post-treated at 1400 and 1500 °C showed (0.2781, 0.2871) and (0.2731, 0.2795) on the CIE chromaticity diagram, and about 78.20 and 79.04 of Ra. The luminous efficiency of the white LED formed from the commercial YAG:Ce phosphor powders was 84.36 lm/W. However, the luminous efficiencies of the white LEDs formed from the YAG:Ce phosphor powders post-treated at 1400 and 1500 °C were 47.74 and 76.64 lm/W.