Red/Blue-Shift Dual-Directional Regulation in Blue-Emitting Ca0.8Ba1.2SiO4:Eu2+ Phosphor on Incorporation of Eu2+/Mg2+ Ions

Blue-emitting phosphors with composition (Ca0.8Ba1.2)1−x Mg x SiO4:yEu2+ (x = 0 to 0.11, y = 0.01 to 0.08) have been synthesized via a high-temperature solid-state reaction route and the effects of Mg2+ and Eu2+ codoping on their morphology, crystal structure, and luminescence properties were investigated. For (Ca0.8Ba1.2)1−x Mg x SiO4:0.04Eu2+, the color changed from light-blue to deep-blue region with increasing Mg2+ content from x = 0 to x = 0.11. For (Ca0.8Ba1.2)0.93Mg0.07SiO4:yEu2+, the emission band showed the opposite shift with increasing y from 1% to 8%. Interestingly, increasing Mg2+ addition led to significant reduction in the full-width at half-maximum (FWHM) from 100 nm to 70 nm. Compared with Mg-free samples, the emission intensity of the Mg-containing material with x = 0.07 was enhanced by ∼100%. The optimum doping levels of Mg2+ and Eu2+ were 0.07 and 0.02 for (Ca0.8Ba1.2)1−x Mg x SiO4:0.04Eu2+ and (Ca0.8Ba1.2)0.93Mg0.07SiO4:yEu2+, respectively. These results indicate that such materials could be good candidate blue-emitting phosphors for use in solid-state lighting and displays.