Preparation and investigation of CaZr4(PO4)6:Dy(3+) single-phase full-color phosphor

A novel single-phase full-color phosphor CaZr4(PO4)6:Dy(3+) has been synthesized by a high-temperature solid-state reaction. X-ray powder diffraction (XRD) analysis and FT-IR spectra confirmed the phase formation of CaZr4(PO4)6:Dy(3+) materials. The photoluminescence excitation and emission spectra, the concentration dependence of the emission intensity, decay curves, ultraviolet-visible absorption spectroscopy and Commission International de I(')Eclairage (CIE) of the phosphor were investigated. The results showed that the phosphor could be efficiently excited by the near ultraviolet (NUV) light region from 340 to 440 nm, and it exhibited blue (487 nm) and yellow (577 nm) emission corresponding to (4)F9/2→(6)H15/2 transitions and (4)F9/2→(6)H13/2 transitions, respectively. The luminescence intensity of Ca(1-x)Zr4(PO4)6:xDy(3+) phosphor firstly increased and then decreased with increasing Dy(3+) concentration, and reached the maximum at x=0.04. The band gap energy of CaZr4(PO4)6 and Ca0.96Zr4(PO4)6:0.04Dy(3+) are about 4.184 eV from the diffuse reflection spectrum. The decay time was also determined for various concentrations of Dy(3+) in CaZr4(PO4)6. The calculated color coordinates lies in the blue white region. Therefore, these obtained results suggest that the prepared phosphors exhibit great potential for use as single-phase full-color phosphor for near ultraviolet white light emitting diodes (NUV WLEDs).