As laser lighting advances toward kilowatt-level power, the thermal stability of phosphors has become a critical bottleneck limiting performance enhancement. To address the issue of luminescence degradation of YAG:Ce phosphors caused by a temperature rise under laser irradiation, we introduced highly thermally conductive AlN into the YAG:Ce matrix and successfully prepared AlN–YAG:Ce composite phosphor ceramics by powder-embedding nitrogen atmosphere sintering. The incorporation of AlN enhances lumen efficiency through increased scattering effects while improving thermal robustness via its inherent high thermal conductivity. The ceramic sample containing 50 vol% AlN exhibits a luminescence intensity comparable to that of YAG:Ce, yet its thermal conductivity is approximately three times higher, reaching 27.2 W·m⁻¹·K⁻¹. A high lumen efficiency of 200.1 lm·W⁻¹ and a suitable correlated color temperature of 4608 K are achieved by the ceramics with 10 vol% AlN under 1.3 W·mm⁻² blue laser diode excitation. Moreover, a laser illumination prototype device incorporating ceramic samples containing 10 vol% AlN and a 10 W blue laser was constructed, emitting white light with an illumination range exceeding 500 m, demonstrating potential applications in laser-driven lighting.

The coexistence of pores in composite phosphor ceramics (CPCs) for solid-state lighting is not necessarily a disadvantage, and it may be more conducive to enhancing luminous efficiency. In this work, x wt% BaAl₂O₄–LuAG:Ce CPCs (x = 1, 3, 5, 10) were fabricated via a solid-state reaction, which involves the coexistence of pores. BaAl₂O₄ can not only function as a sintering aid but also form secondary phases serving as scattering centers. The 3 wt% BaAl₂O₄–LuAG:Ce exhibits an intriguing microstructure, where large and small grains of LuAG:Ce coexist alongside pores and secondary phases, demonstrating better luminescent properties. Under 0.92 W laser excitation at 450 nm, 3 wt% BaAl₂O₄–LuAG:Ce exhibits an optimum luminous efficiency of 237 lm/W and a luminous flux of 218 lm. When the laser power reached 4.3 W, 3 wt% BaAl₂O₄–LuAG:Ce exhibited an optimal luminous flux of 1015 lm, which shows the potential for application in solid-state lighting (SSL).