Towards long-lifetime high-performance warm w-LEDs: Fabricating chromaticity-tunable glass ceramic using an ultra-low melting Sn-P-F-O glass

Abstract

The strong demands for “high-power” w-LEDs stimulate development of the all-inorganic glass ceramic (GC) phosphors with admirable thermal/chemical reliabilities. Herein, an ultra-low melting Sn-P-F-O glass was successfully prepared, demonstrating as an appropriate host to accommodate yellow YAG:Ce3+ and red CASN:Eu2+ without degrading their original luminescent properties. The yellow and red GCs yield QE as high as 92.0% and 88.6%, respectively. Moreover, they exhibit excellent resistance to thermal quenching, i.e., only 9.5% and 3.0% decreases in luminescence intensity at 150°C compared with that at room temperature. Remarkably, LED using the YAG:Ce3+/CASN:Eu2+ co-sintered GC as color converter yields bright warm white light with CCT of 3554K, under 350mA current, highlighting a new record in LE of 90.71lm/W among the GC-based warm w-LEDs. Accelerated experiments demonstrate the presently studied GC also exhibits a superior thermal stability, therefore is capable for operating at high power condition for a long time.