Synthesis and luminescent characterization of submicron-sized Y3Al5O12:Ce3+ yellow phosphor by coprecipitation method

By using metal nitrates as starting materials, cerium-doped yttrium aluminium garnet (Y3Al5O12:Ce3+) yellow phosphors were prepared by coprecipitation method with NH3 center dot H2O-NH4HCO3 system as the precipitating agent. The formation process and structure of the phosphor powders were investigated by means of DTA-TGA and XRD. And the effect of fluoride as additive on the morphology, crystallite and photoluminescent properties of Y3Al5O12:Ce3+ was studied by photoluminescent excitation and emission spectra and SEM. The result shows that completely crystallized phosphors are obtained at 900 degrees C, which is more than 300 degrees C lower than the temperature of solid-state method. The phosphor particles have spheroidal shapes with uniform distribution, and their sizes are 0.3 similar to 1 mu m. The emission spectrum excited by 468 nm shows a characteristic wide band with the peak at about 532nm. A small quantity of fluoride as additive is necessary for enhancing photoluminescent intensity Of Y3Al5O12: Ce3+ phosphors, and improving the morphology. The Y3Al5O12:Ce3+ phosphors prepared can be used together with a InGaN blue LED to achieve white light when excited by blue light of the LED. The achieved color temperature is 5 571 K, with a device luminous efficacy of 45 lm center dot W-1, a color rendering index of 79.9 and a color point near the coordinate x=0.330 8, y=0.347 6.