High-performance Al2O3-Ce:YAG ceramics for white LED and LD by the optimization of Ce3+ concentration

Al2O3-Ce:YAG composite ceramics are widely used in high-power white light-emitting diodes (LED) and laser diode (LD), because of their good optical performance and high luminous efficiency, particularly, excellent thermal conductivity. In this study, we prepared Al2O3-Ce:YAG composite ceramics doped with different con-centrations of Ce3+ by vacuum sintering technique. The emission peak of Ce3+ is redshifted from 533 nm to 553 nm with the increase of Ce3+ concentration from 0.1 at% to 1.5 at%. When excited by a blue LED with 455 nm, the luminous efficiency of the ceramic doped with 1.2 at% Ce3+ reached 106 lm/W and a low correlated color temperature of 3600 K was achieved. Moreover, when excited by the 450 nm blue LD with 5.8 W of electrical power, a higher luminous efficiency of 171 lm/W was obtained with 0.5 at% Ce3+ doped. These results indicate that Al2O3-Ce:YAG composite ceramics doped with Ce3+ concentrations of 1.2 at% exhibit excellent optical properties and are promising phosphor-convert materials for white LED and LD lighting applications.