Effect of Dy(3+) or Eu(2+) co-activator on a BaCa(SO4)2:Ce(3+) mixed alkaline earth sulfate phosphor.

The individual emission and energy transfer between Ce(3+) and Eu(2+) or Dy(3+) in BaCa(SO4)2 mixed alkaline earth sulfate phosphor prepared using a co-precipitation method is described. The phosphor was characterized by X-ray diffraction (XRD) and photoluminescence (PL) studies and doped by Ce;Eu and Dy rare earths. All phosphors showed excellent blue-orange emission on excitation with UV light. PL measurements reveal that the emission intensity of Eu(2+) or Dy(3+) dopants is greater than when they are co-doped with Ce(3+). An efficient Ce(3+) → Eu(2+) [(2) T2g(4f(6)5d) → (8)S7/2(4f7)] and Ce(3+) → Dy(3+) ((4)F9/2 → (6)H15/2 and (4)F9/2 → (6)H13/2) energy transfer takes place in the BaCa(SO4)2 host. A strong blue emission peak was observed at 462 nm for Eu(2+) ions and an orange emission peak at 574 nm for Dy(3+) ions. Hence, this phosphor may be used as a lamp phosphor.