Ultrahigh Power Density LuAG:Ce Green Converters For High-Luminance Laser-Driven Solid State Lighting

Lu3Al5O12:Ce (LuAG:Ce) phosphor has been designed and fabricated into various forms of green fluorescent converters and plays a critical role in the field of solid-state laser lighting. Phosphor in glass (PiG) and phosphor in glass film (PiGF) are expected to be viable strategies for high-power and high-brightness laser diode (LD) illumination due to their easy synthesis and low cost. In this study, LuAG:Ce-PiG with an internal quantum efficiency of 90.5% is prepared by investigating the sintering conditions and combining with a borosilicate glass. It possesses a luminous flux (LF) of 584 lm and luminous efficiency (LE) of 225 lm W-1 @ 20 W mm(-2). On this basis, LuAG:Ce-PiG sapphire film (LuAG:Ce-PiGSF) with high thermal conduction (10.26 W (m K) (-1)) is successfully sintered on the sapphire to obtain the LF of 833 lm and LE of 252 lm W-1 @ 36.36 W mm(-2). The maximum tolerated power density can reach 45.45 W mm(-2). In addition, when the color converters are placed in a commercial LD transmission module and continuously light for 24 h at 16.5 W, the relative light intensity only decreases by 14.15% and 12.82%, respectively. Therefore, it is believed that the work has promising applications in laser illumination and accelerating the development of LD lighting.