Heat-conducting LSN:Ce-in-glass film on AlN substrate for high-brightness laser-driven white lighting

Abstract

Laser diodes (LDs) combined with color converters have been considered as new-generation high-brightness white light source. Whereas, the luminescence of phosphor materials is easily influenced by accumulated heat originating from laser-driven conversion. In order to alleviate the thermal effect under focused laser of high-power, we proposed a high-luminescence laser-driven color converter of heat-conducting La3Si6N11:Ce3+ (LSN:Ce) phosphor-in-glass (PiG). The LSN:Ce nitride phosphor exhibits excellent opto-thermal property. The LSN:Ce-PiG-AlN converter was fabricated by sintering the LSN:Ce-PiG layer (∼50 μm) upon a AlN ceramic substrate. Due to excellent luminescence of LSN:Ce and high thermal conductivity of AlN, the LSN:Ce-PiG-AlN converter achieves a luminous flux (LF) of 376.1 lm, a luminous efficiency (LE) of 158 lm/W, and a correlated color temperature (CCT) of 4462 K under 2.39 W laser excitation. In addition, the temperature of PiG film surface still stays low level (<150 °C) when driven by 4.82 W laser irradiation. The proposed LSN:Ce-PiG-AlN converter is a high-performance and promising phosphor converter for high-luminescence white laser lighting.