The performance tuning of NaCaTiTaO6:Dy3+, Eu3+ phosphor by employing the co-doping strategy for white LED application

Abstract

A series of Dy3+ doped and Dy3+, Eu3+ co-doped NaCaTiTaO6 (NCTT) phosphors with the orthorhombic perovskite-type structures were prepared by a solid-state reaction method. The successful synthesis of the target samples was confirmed through various characterization techniques, such as XRD and Rietveld refinement, SEM, EDX spectroscopy, as well as elemental mapping. The optimal Dy3+ doping concentration of NCTT:xDy3+ under n-UV excitation was 0.10 mol. The phenomenon of efficient energy transfer between Dy3+ and Eu3+ ions was observed in the NCTT:0.1Dy3+/yEu3+ samples, as evidenced by the shortened lifetimes. Meanwhile, in the NCTT:0.1Dy3+/0.15Eu3+ sample, the PL intensity of Eu3+ ion at 420 K still maintained at 72.41% of that at 300 K, while that of Dy3+ ion is 82.35%, displaying its brilliant thermal stability. The performance of the fabricated white LED device using NCTT:0.1Dy3+/0.15Eu3+ as red phosphor was found to be outstanding, with Ra of 88, CCT of 5868 K, as well as excellent CIE chromaticity coordinates (0.325, 0.333), suggesting that NCTT:0.1Dy3+/0.15Eu3+ can be used as reddish-orange phosphors for w-LEDs in lightings and displays.