High Luminescence Saturation Y3Al5O12: Ce3+-Diamond Composite Color Converter for High-Brightness Laser-Driven White Lighting

Phosphor-converted laser lighting confronts enormous challenges in the development of color converters with high luminescence saturation owing to the thermal issues from laser irradiation and phosphor conversion. Herein, a high luminescence saturation Y3Al5O12: Ce3+-diamond (YAG-diamond) composite color converter by introducing diamond particles in phosphor-in-glass film (PiGF) coated on transparent sapphire substrate is proposed for high-brightness laser-driven white lighting. By optimizing the diamond content to 6 wt.%, the YAG-diamond converter shows a thermal conductivity (TC) of 14.7 W<middle dot>m(-1)<middle dot>K-1 and displays higher luminescence intensity at 175 degrees C (1.15 times that at 25 degrees C). Under laser excitation, the YAG-diamond converter achieves a luminous flux (LF) of 1990 lm at the laser power density (LPD) saturation threshold (ST) of 24.82 W<middle dot>mm(-2), which is far better than the PiGF@sapphire converter with a LF of 1364 lm@17.64 W<middle dot>mm(-2). The laser-driven converter yields stable white laser light with a correlated color temperature (CCT) of 5714 K and a chromaticity coordinate of (0.3278, 0.3372) at the ST of 24.82 W<middle dot>mm(-2). Furthermore, the working temperature of the converter is decreased by 59 degrees C (26.6%) under LPD of 10.89 W<middle dot>mm(-2). These results indicate that the proposed YAG-diamond composite converter displays excellent opto-thermal performances, which may be a promising luminescence material in high-brightness white laser lighting.