Pore-coexisting BaAl₂O₄–LuAG:Ce composite phosphor ceramics for solid-state 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).