Crystal structure and luminescence property of a single-phase white light emission phosphor Sr3YNa(PO4)3F:Dy3+

A series of single-phase Sr₃YNa(PO₄)₃F:Dy³⁺ phosphors were successfully synthesized via a conventional solid state reaction process. The powder X-ray diffraction patterns were utilized to confirm the phase composite and crystal structure. The phosphor could be excited by the ultraviolet visible light in the region from 300 to 420 nm, and it shown two dominant emission bands peaking at 484 nm (blue light) and 580 nm (yellow light) which originated from the transitions of ⁴F_9/2→⁶H_15/2 and ⁴F_9/2→⁶H_13/2 of Dy³⁺, respectively. The optimum dopant concentration of Dy³⁺ ions was confirmed to be 7 mol% in Sr₃YNa(PO₄)₃F:Dy³⁺ system and the concentration quenching mechanism is dipole–dipole interaction. The lifetime values of Dy³⁺ ions at different concentrations (x?=?0.03, 0.05, 0.07, 0.09 and 0.11) were determined to be about 0.855, 0.759, 0.686, 0.606 and 0.546 ms, respectively. The thermal stability of luminescence of Sr₃YNa(PO₄)₃F:0.07Dy³⁺ phosphor was also investigated and the activated energy was deduced to be 0.228 eV, which shows good thermal stability. The chromaticity coordinates fall in the white-light region calculated by the emission spectrum. These results show that Sr₃YNa(PO₄)₃F:Dy³⁺ phosphor can be a promising white emitting phosphor for white LEDs.