Preparation and investigation of Dy3+-doped Ca9LiGd2/3(PO4)7 single-phase full-color phosphor

Abstract

Novel single-phased white-light-emitting Ca9LiGd2/3(PO4)7:xDy3+ (x = 0.02, 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30) β-Ca3(PO4)2-type phosphate phosphors were synthesized. The phase structure, luminescence, and thermal stability of the phosphors were characterized by X-ray powder diffraction analysis, photoluminescence excitation and emission spectra, thermal quenching, and decay curves. XRD analysis confirmed the phase formation of Ca9LiGd2/3(PO4)7:Dy3+ materials. Under the excitation of 352 nm, the emission of the Ca9LiGd2/3(PO4)7:0.20Dy3+ sample centered at blue (488 nm) and yellow (580 nm), which corresponded to 4F9/2–6H15/2 transition and 4F9/2–6H13/2 transition. The optimum dopant concentration of Dy3+ ions was around 20 mol%, and the critical transfer distance of Dy3+ was calculated as 18 Å. The thermal-quenching temperature was above 500 K for Ca9LiGd2/3(PO4)7:0.20Dy3+. The developed phosphor has a great potential as a single-component white-light-emitting phosphor for UV-light-emitting diodes.