Synthesis and characterization of a new double perovskite phosphor: NaCaTiTaO6:Dy3+ with high thermal stability for w-LEDs application

A new yellow-emitting phosphor, NaCaTiTaO 6 :Dy 3+ , was synthesized via solid-phase synthesis at 1300 ℃. X-ray diffraction (XRD) analysis and Rietveld refinement showed that the prepared phosphors exhibited a stable double perovskite structure. The particle size of the phosphor was around 3.8 μm. The maximum emission peak at 574 nm is attributed to the 4 F 9/2 → 6 H 13/2 energy level transition under irradiation at 389 nm. The optimum Dy 3+ doping concentration is 0.10 M equivalent, and concentration quenching is due to the nearest neighbor ion interaction. The luminescence intensity of the phosphor was reduced by only 15% at 420 K, exhibiting high thermal stability. Quantum yield (QY) was measured to be 26.31%. Finally, the Commission International de I’Eclairage (CIE) color coordinate of the phosphor for white light emitting diode (w-LED) was (0.314, 0.323), with a color rendering index ( R a ) of 92 and a correlated color temperature (CCT) of 5578 K. Above all, the Dy 3+ -doped double perovskite NaCaTiTaO 6 :Dy 3+ phosphor is expected to be used in w-LEDs.