Structural and luminescent properties of Dy-doped CaWO phosphors for white-light display applications.

This study unveils the synthesis and in-depth characterization of Dy-doped calcium tungstate (CaWO) double perovskite phosphors, designed for advanced photoluminescence (PL) applications. These phosphors, with Dy 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 CaWO:Dy phosphors emit intense white light, driven by the F → H (485 nm) and F → H (576 nm) transitions of Dy ions. The effects of doping concentration on PL intensity and concentration quenching were thoroughly investigated. PL decay lifetime analysis at = 278 nm and = 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.