Synthesis and luminescence of Dy3+-activated NaSrPO4 phosphors for novel white light generation

Abstract

The Dy3+-doped NaSrPO4 phosphor powders have been synthesized by solid state reaction. All samples were verified to be in a pure NaSrPO4 phase by X-ray diffraction analysis for all the Dy3+ doping concentrations. The room temperature excitation spectra of NaSrPO4:Dy3+ phosphors illustrated that they could easily be excited by UV–Visible light corresponding f − f transitions of Dy3+. The photoluminescence spectra exhibit two main bands centered at 481 nm (blue) and 573 nm (yellow), which originate from the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions of Dy3+, respectively. The two bands combined to form a white light with the chromaticity coordinates varying with the concentrations of Dy3+. The chromaticity coordinates were measured and mapped in the Commission International de L’Ecllairage 1931 diagram, indicating that they distributed around (0.30, 0.34) of the colorless point D65. The dependence of luminescence intensity onto Dy3+ concentration was investigated and the concentration quenching mechanism for NaSrPO4:Dy3+ was discussed.