Emission-enhanced high-performance Al2O3-Ce: (Y, Tb)AG composite ceramic phosphors for high-brightness white LED/LD illumination

Owing to their excellent thermal robustness, high light saturation threshold, and high luminous efficiency, Al2O3-Ce doped garnet composite ceramic phosphors (CCPs) have attracted extensive attention for applications in laser illumination. In this study, we fabricated the high-performance Al2O3-Ce: (Y, Tb)3Al5O12 CCPs via a solid-state reaction. It was found that the bidirectional energy transfer process between Ce3+ and Tb3+ can promote the absorption of Ce3+ for blue light, which can effectively enhance the yellow light emission intensity and reduce the correlated color temperature (CCT) of samples. Based on this effect, Al2O3-Ce: (Y0.9Tb0.1)3Al5O12 CCPs show the best thermal quenching and luminous efficiency performance. Its luminous efficiency at 450 K drops by 17% from the initial luminous efficiency, and its luminescence efficiency reaches 262 lm/W when driven by a 2.24 W blue laser. In addition, the CCT of samples gradually decreases from 8329 K to 4460 K with the increase of Tb3+, which is of great significance for realizing the white LD lighting.

Automated summary

Al2O3-Ce doped garnet composite ceramic phosphors (CCPs) are fabricated via solid-state reaction and exhibit excellent thermal quenching and luminous efficiency. The bidirectional energy transfer process between Ce3+ and Tb3+ enhances yellow light emission and lowers correlated color temperature (CCT). The Al2O3-Ce: (Y0.9Tb0.1)3Al5O12 CCPs show the best performance, with a 17% drop in luminous efficiency at 450 K and a luminescence efficiency of 262 lm/W when driven by a 2.24 W blue laser. The decrease in CCT with increasing Tb3+ content is significant for white LD lighting.