Solid-state laser lighting fabricated by combining blue laser diodes (LDs) and yellow-emitting phosphor converters has attracted great attention in high-luminance applications. However, the achievement of high-power laser lighting is significantly affected by the thermal quenching effect of phosphor converter materials. Therefore, component regulation and performance optimization are required to improve the thermal conductivity and luminescence uniformity of phosphor converters. In this work, a series of Al2O3-YAG:Ce composite ceramic phosphors with different Al2O3 contents were prepared by solid-state reactive sintering. The influences of Al2O3 contents on the microstructure, phase composition, optical properties and thermal performance of the Al2O3-YAG:Ce ceramic phosphors were investigated in detail. The total transmittance of the Al2O3-YAG:Ce ceramic phosphors at 800 nm tends to decline (82.6%→23.6%) with the increase of Al2O3 content (0→90%). Both excitation and emission intensity of the Al2O3-YAG:Ce ceramic phosphors initially increase and then decrease with increasing Al2O3 content.When the weight ratio of Al2O3/Al2O3-YAG:Ce is 70%, the ceramic phosphor exhibits a high thermal conductivity of 25.7 W• m -1 •K -1 at room temperature and the highest emission intensity. A high luminous flux of 3724 lm and luminous efficacy of 239.4 lm• W -1 are obtained when pumping the 70% Al2O3-YAG:Ce ceramic phosphor with blue LDs at a power density of 20 W• mm -2 . Additionally, the luminous efficacy only decreases by 10.5% and the luminous flux continues to increase without showing luminescence saturation, when the power density increases from 1 to 20 W• mm -2 . Thus, the Al2O3-YAG:Ce composite ceramic phosphors are promising in high-power laser lighting for excellent luminous efficiency and improved thermal stability.

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In this work, a series of Al2O3–Ce:YAG phosphor powders were synthesized by regulating the excess Al3+ of (Y,Ce)3Al5O12 via coprecipitation method for the first time, where Al3+, Ce3+, and Y3+ elements were uniformly distributed. With the increase of Al3+ content, the morphology of the powders changed from wormlike shapes to flaky shapes, and Y3Al5O12 phases had a tendency to convert to YAlO3 phases. The x wt.% Al2O3–(Y0.999Ce0.001)3Al5O12 (x = 20, 30, 40, 50, 60, and 70) composite phosphor ceramics (CPCs) were obtained by vacuum sintering (1775°C × 10 h), where Al2O3 and Ce:YAG phases were also well‐distributed. When the Al2O3 content was 30–40 wt.%, the average grain size of Al2O3 was close to that of Ce:YAG. A solid‐state laser lighting device was constructed by a 450 nm laser source and CPCs in a reflection mode. By adjusting the laser power, the correlated color temperature (CCT) values of white laser diodes (LDs) were achieved close to the standard white light of 6500 K. Impressively, the white LDs equipped with the 40 wt.% Al2O3‐containing CPCs showed the optimum CCT of 6498 K (color coordinates: 0.31 and 0.38), as well as a high luminous flux of 1169 lm and efficiency of 166 lm/W at the LD power of 7.05 W. This work has provided a potential idea to optimize the composition uniformity of Al2O3–Ce:YAG CPCs as also to explore their excellent performance in the application of white laser lighting.