Phase composition design of high performance Al2O3-YAG: Ce ceramic phosphors for high-power laser lighting

The combination of laser diode (LD) chip and Al 2 O 3 -YAG: Ce composite ceramic phosphor is considered as one of the best solutions for high-power laser lighting. However, in previous studies on Al 2 O 3 -YAG: Ce composite ceramics, the effects of large-scale compositional changes on their luminous properties were rarely noticed, which hinders the understanding of the relationship between ceramic phase composition and the comprehensive properties of white LDs. In this paper, we prepared Al 2 O 3 -YAG: Ce composite ceramic phosphors with Ce 3+ and Al 2 O 3 concentrations varying widely in the range of 0.5–5 at% and 0–90 at%, respectively. An impurity phase was found in samples with high Ce 3+ -Al 2 O 3 concentration by SEM images and verified to be CeAl 11 O 18 by XRD patterns. Under high power density laser (2.3–10 W/mm 2 ) excitation, the Ce 3+ concentrations corresponding to the highest luminous efficiency of the ceramic increase from 0.5 at% to 3 at% with the introduction of Al 2 O 3 . The temperature quenching effect of ceramics is also alleviated. The CRI of ceramics first decreases and then increases with the increase of Al 2 O 3 concentration, and the CRI of 90 at% Al 2 O 3 samples is the highest (75.9). The results show that the introduction of Al 2 O 3 can improve the performance of ceramics from all aspects as long as the optimal composition of Al 2 O 3 - YAG: Ce composite ceramics is selected. • Al 2 O 3 –YAG: Ce composite ceramic phosphors with phase composition varying in a wide range have been fabricated. • The impurity phase CeAl 11 O 18 was found in samples with high Ce 3+ concentrations. • The luminous efficiency, CCT and CRI of the ceramics excited by high-power density laser were measured.