The energy transfer and effect of doped Mg2+ in Ca3Sc2Si3O12:Ce3+, Pr3+ phosphor for white LEDs

The energy transfer and luminescence properties in the Ce3+ and Pr3+ co-activated Ca3Sc2Si3O12 (CSS) silicate garnet are studied in our work. The addition of Pr3+ exhibits a red emission around 610 nm in the green phosphor CSS: Ce3+, but the amount of Pr3+ incorporated into the phosphor is very limited due to the charge mismatch when Pr3+ substitutes for Ca2+ in CSS. In order to promote Pr3+ incorporation into CSS lattices to enhance the red emission component, the addition of Mg2+ incorporated into Sc3+ site is performed to compensate the residual positive charge caused by the substitution of Pr3+ for Ca2+ in CSS. Finally, a white LED with color rendering index of 80 and correlated color temperature of 8715 K is obtained by combining the single CSS: 0.05Ce(3+), 0.01Pr(3+), 0.3Mg(2+) phosphor with a blue-emitting InGaN LED chip.