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

Highlights: • A novel single-phased Ca₉LiGd_2/3(PO₄)₇:xDy³⁺ phosphor was firstly synthesized. • Its structure, luminescent properties are well studied and characterized. • It was promising as a single-component white-light-emitting phosphor for w-LEDs. - Abstract: Novel single-phased white-light-emitting Ca₉LiGd_2/3(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 Ca₉LiGd_2/3(PO₄)₇:Dy³⁺ materials. Under the excitation of 352 nm, the emission of the Ca₉LiGd_2/3(PO₄)₇:0.20Dy³⁺ sample centered at blue (488 nm) and yellow (580 nm), which corresponded to ⁴F_9/2–⁶H_15/2 transition and ⁴F_9/2–⁶H_13/2 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 Ca₉LiGd_2/3(PO₄)₇:0.20Dy³⁺. The developed phosphor has a great potential as a single-component white-light-emitting phosphor for UV-light-emitting diodes.