Ce3+ Doped yttrium aluminum and lutetium aluminum garnet embedded in a soda-lime silica glass by a sintering technique

Commercial Ce3+ doped yttrium aluminum (Ce3+:YAG) and lutetium aluminum garnet (Ce3+:LuAG) powders were mixed with powdered soda-lime silicate glass with the molar composition 15.5 Na2O / 10.7 CaO / 73.8 SiO2. Then the mixtures were sintered at temperatures in the range from 800 to 1000 degrees C for 10 and 30 min. XRD-patterns proved that the samples contain only the respective garnet phases. During sintering at 1000 degrees C, a notable dissolution of the garnet phase took place as proved by the occurrence of the typical blue emission of Ce3+ in the glassy phase if excited with UV light. Dissolution of the phosphors is much lower at a processing temperature of 800 degrees C. Additionally, the dissolution process is strongly affected by the chemical composition of the glass. The concentration of the phosphors in the glass matrix had only a minor effect on the fluorescence intensity. The efficiency in lm/W increases with the sample thickness and is for the Ce3+:LuAG sample nearly as high as for polymer embedded samples, while it is slightly smaller for the Ce3+:YAG samples. (C)2015 Optical Society of America