An Investigation on the Luminescence and Ce(3+) -> Eu(2+) Energy Transfer in Ca(9)Y(PO(4))(7):Ce(3+),Eu(2+) Phosphor

Abstract

A series of Ce(3+)- and Eu(2+)-coactivated Ca(9)Y(PO(4))(7) phosphors were synthesized by high temperature solid-state reactions. The Ca(9)Y(PO(4))(7):Ce(3+), Eu(2+) phosphor showed two emission bands under 292 nm excitation:the one observed at 342 nm was attributed to the 4f(0)5d(1) -> 4f(1) transition of Ce(3+) ion emission, and the other found at 492 nm was assigned to the 4 f(6)5d(1) -> 4f(7) transition of Eu(2+) ions. Through an effective resonance-type energy transfer, the Ca(9)Y(PO(4))(7):Ce(3+), Eu(2+) phosphors exhibit a systematically varied hues from ultraviolet to blue-greenish and the relative intensity of ultraviolet and blue-greenish emissions can be tuned by properly tuning the relative dopant composition of Ce(3+)/Eu(2+). The energy transfer from a sensitizer Ce(3+) to an activator Eu(2+) in Ca(9)Y(PO(4))(7) host matrix was studied and demonstrated to be a resonant type via a dipole-dipole mechanism based on the decay lifetime analysis. Furthermore, we have calculated the critical distance for Ce(3+) -> Eu(2+) energy transfer to be about 30.7 angstrom by both concentration quenching and spectral overlap methods. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.029111jes] All rights reserved.