Journal of the American Ceramic Society, Vol.102, No.4, 2053-2065, 2019
Erosion behavior and luminescence properties of Y3Al5O12:Ce3+-embedded calcium bismuth borate glass-ceramics for WLEDs
Current white light emitting diodes (WLEDs) have poor thermal stability and lack red-light, which restrict their applications in high-power and high-color-rendering-index solid-state lighting. YAG glass-ceramics provide an efficient way to resolve these problems. Herein, novel YAG-embedded calcium bismuth borate glass-ceramics (YAG-GCs) with Eu3+ doping were prepared using a rapid melt quenching technique. The precursor glass exhibits superior YAG refractive index matching and high transmittance. Differential scanning calorimeter simulations verify YAG particles react with the precursor glass. The degree of YAG erosion is slight but monotonously increases with the co-sintering temperature from 640 to 700 degrees C. The erosion products probably contain YAB (Al3Y(BO3)(4)), Al3Eu(BO3)(4), Bi24B2O39, and Ca12Al14O33 phases, and the Bi ion valence state is maintained during the reaction process. The energy transfer from Ce3+ to Eu3+ is suppressed. The YAG-GC PL intensities monotonously increase as the co-sintering temperature decrease from 640 to 700 degrees C and the YAG content increase from 2.5 to 7 wt.%. The optical parameters of a WLEDs packed by YAG-GCs and blue chips are a luminous efficiency of 105.3 lm/W, correlated color temperature of 3940 K and color rendering index of 70.1. The as-prepared YAG-GCs are promising candidates for high-power, warm WLEDs due to their superior thermal stability, high quantum efficiency, and low cost.