The Enhanced Red-Emitting Fluorescence of Ca4(Po4)2o : Eu2+ Phosphor by Energy Transfer Technology

A series of Ca4(PO4)2O: Eu2+ and Ca4(PO4)2O: Eu2+, Dy3+ red-emitting phosphors were synthesized by traditional solid-state reaction method. The crystal structure, particle morphology and photoluminescence properties were characterized by X-ray diffractometer (XRD), field-emission scanning electron microscope (FE-SEM) and fluorescence spectrometer, respectively. Under excitation of 460 nm, the Ca4(PO4)2O: Eu2+ phosphor exhibits a red emission band at 645nm, which is attributed to 4f65d1 → 4f7 transition of Eu2+ ion. In order to improve the red emission of, Dy3+ ions are incorporated in the Ca4(PO4)2O lattice. It can be found that the emission intensity of the sample co-doped with Dy3+ is obviously enhanced in contrast to that of Ca3.93(PO4)2O: 0.07Eu2+ phosphor and the optimal doping concentration of Dy3+ is ~7 mol%. Furthermore, the emission intensity of Ca4(PO4)2O: Eu2+, Dy3+ phosphors increased by 33% compared with 1: 1 mechanical mixture of Ca4(PO4)2O: 0.07Eu2+ and Ca4(PO4)2O: 0.04Dy3+ phosphors. The energy transfer from Dy3+ to Eu2+ is then verified as electric dipole-dipole interaction, which enhances the red emission of Eu2+