Structural and luminescent properties of Dy ³⁺ -doped Ca ₃ WO ₆ phosphors for white-light display applications

This study unveils the synthesis and in-depth characterization of Dy³⁺-doped calcium tungstate (Ca₃WO₆) double perovskite phosphors, designed for advanced photoluminescence (PL) applications. These phosphors, with Dy³⁺ doping levels of 0.5-2.5 mol%, were synthesized using a high-temperature solid-state reaction method. Structural and morphological properties were rigorously evaluated through X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDAX). Rietveld refinement of XRD data confirmed a monoclinic crystal structure, while SEM revealed a porous morphology attributed to high-temperature calcination, with EDAX verifying uniform elemental distribution. Excited at 278 nm, the Ca₃WO₆:Dy³⁺ phosphors emit intense white light, driven by the ⁴F_9/2 → ⁶H_15/2 (485 nm) and ⁴F_9/2 → ⁶H_13/2 (576 nm) transitions of Dy³⁺ ions. The effects of doping concentration on PL intensity and concentration quenching were thoroughly investigated. PL decay lifetime analysis at <i>λ</i> _ex = 278 nm and <i>λ</i> _em = 576 nm elucidated the decay kinetics, affirming the phosphor's high external quantum yield (∼59%). CIE chromaticity coordinates place the emission squarely in the white light spectrum, underscoring the exceptional potential of these phosphors for advanced white light-emitting display technologies.