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

The energy transfer and luminescence properties in the Ce(3+) and Pr(3+) co-activated Ca3Sc2Si3O12 (CSS) silicate garnet are studied in our work. The addition of Pr(3+) exhibits a red emission around 610 nm in the green phosphor CSS:Ce(3+), but the amount of Pr(3+) incorporated into the phosphor is very limited due to the charge mismatch when Pr(3+) substitutes for Ca(2+) in CSS. In order to promote Pr(3+) incorporation into CSS lattices to enhance the red emission component, the addition of Mg(2+) incorporated into Sc(3+) site is performed to compensate the residual positive charge caused by the substitution of Pr(3+) for Ca(2+) 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.