Synthesis and luminescence characterization of Dy³⁺/Sm³⁺ Co-doped Y₂MgTiO₆ double-perovskite phosphors for warm WLED

Y2MgTiO6:Dy³⁺/Sm³⁺ double-perovskite phosphors were synthesized using the high-temperature solid-state reaction method, and their luminescence properties were examined through various techniques, including Rietveld refinement, excitation and emission spectra, Commission Internationale de l'Eclairage (CIE) analysis, and band gap simulation. Ab initio calculations were performed to analyze the band gap and density of states, allowing for the prediction of the effect of Dy³⁺ and Sm³⁺ doping on emission intensity. The emission spectra of Y₂MgTiO₆ (YMTO) doped with Sm³⁺ and Dy³⁺ exhibited maximum peaks at 602 nm and 575 nm, respectively, when excited at 325 nm. Both YMTO:Sm³⁺ and YMTO:Dy³⁺ demonstrated excellent thermal stability. The CIE coordinates of YMTO doped with 1 mol% Dy³⁺ were determined to be (0.3771, 0.3804), with a correlated color temperature (CCT) of 4115 K, confirming its suitability for warm white light applications. Introducing 1 mol% and 3 mol% of Sm³⁺ ions into the Dy³⁺/Sm³⁺ co-doped YMTO allowed for adjustable CCT values of 3719 K and 3302 K, respectively, further enhancing their potential for use in warm white light-emitting diodes (WLEDs).