Single-phased white-light-emitting Ca4(PO4)2O:Ce3+,Eu2+ phosphors based on energy transfer

Abstract

A novel single-composition Ca₄(PO₄)₂O:Ce³⁺,Eu²⁺ phosphor emitting white light was synthesized by conventional solid-state reaction for light-emitting diode applications. X-ray diffraction, photoluminescence spectra, and luminescence decay spectra were used to characterize the samples. Energy transfer from Ce³⁺ to Eu²⁺ ions was observed in the co-doped samples, and the transfer mechanism in the Ca₄(PO₄)₂O:Ce³⁺,Eu²⁺ phosphors was dipole–dipole interaction. The emission hue of Ca₄(PO₄)₂O:Ce³⁺,Eu²⁺ was found to vary from blue (0.165, 0.188) to white (0.332, 0.300) and eventually to orange (0.519, 0.366) by precisely controlling the ratio of Ce³⁺ to Eu²⁺. The combination of a 380 nm near-ultraviolet chip with a Ca₄(PO₄)₂O:0.02Ce³⁺,0.012Eu²⁺ phosphor produced a diode emitting white light with ultra-wideband emission and a correlated color temperature of 4124 K. Overall, results indicated that the prepared samples may be potentially applied in white-light-emitting diodes.