Luminescence properties of long-persistence silicate phosphors

Abstract

Tb 3+-doped and (Ce 3+, Tb 3+)-codoped Ca 0.5Sr 1.5Al 2SiO 7 were prepared using a solid-state reaction at 1273 K for 3 h in air and 1623 K for 6 h in a weakly reductive atmosphere of 5% H 2–95% N 2 gas. The resultant (Ce 3+, Tb 3+)-codoped Ca 0.5Sr 1.5Al 2SiO 7 phosphor shows four main emission peaks: one at 386 nm for Ce 3+ and three at 483, 542 and 591 nm for Tb 3+. Emission intensity of Tb 3+ in the (Ce 3+, Tb 3+)-codoped phosphor was five times greater than that of the Tb 3+ single-doped phosphor because of the energy transfer from Ce 3+ to Tb 3+. The codoped phosphor showed long-persistence white phosphorescence.