Luminescence of Eu and Ce in K3Ca2(SO4)3F fluoride material

A new halophosphor K3Ca2(SO4)3F activated by Eu or Ce and K3Ca2(SO4)3F:Ce,Eu co-doped halosulfate phosphor has been synthesized by the co-precipitation method and characterized for its photoluminescence (PL). The PL emission spectra of the K3Ca2(SO4)3F:Ce phosphor show emission at 334 nm when excited at 278 nm due to 5d → 4f transition of Ce(3+) ions. In the K3Ca2(SO4)3F:Eu lattice, Eu(2+) (440 nm) as well as Eu(3+) (596 nm and 615 nm) emissions have been observed showing (5) D0 →(7) F1 and (5) D0 →(7) F2 transition of the Eu(3+) ion, which is in the blue and red region of the visible spectrum respectively. The trivalent europium ion is very useful for studying the nature of metal coordination in various systems owing to its non-degenerate emitting (5) D0 state. K3Ca2(SO4)3F:Ce,Eu is suitable for Ce(3+) → Eu(2+) → Eu(3+) energy transfer in which Ce(3+) and Eu(2+) play the role of sensitizers and Eu(2+) and Eu(3+) act as the activators. The observations presented in this paper are relevant for lamp phosphors.