Orange-red emitting Eu²⁺-activated (Sr_0.883Ba_0.1Lu_0.0.17)₃(Si_0.95Al_0.05)O₅ phosphor: Structure, photoluminescence, and application in white LEDs

Orange-red emitting (Sr_0.883-xBa_0.1Lu_0.0.17Eu_x)₃(Si_0.95Al_0.05)O₅ phosphors were synthesized by conventional solid-state reaction. The effect of NH₄F flux on structural and luminescent properties of phosphors was investigated. Results suggested that the optimal content of NH₄F flux was 3 wt.% and the optimal doping concentration of Eu²⁺ was x=0.023 mol. The phosphors showed intense absorption in near-ultraviolet to blue region and exhibited orange-red emissions. The thermal stability of synthesized (Sr_0.86Ba_0.1Lu_0.017Eu_0.023)₃(Si_0.95Al_0.05)O₅ phosphor were examined and compared with commercial YAG:Ce³⁺ yellow phosphors. Combining an InGaN blue 460 nm chip and a white-emitting (Sr_0.86Ba_0.1Lu_0.017Eu_0.023)₃(Si_0.95Al_0.05)O₅ phosphor produced a white- light LED, demonstrating CIE chromaticity coordinates of (0.314, 0.329) and a color temperature of 5595 K. All results showed that this phosphor is a promising candidate as orange-red emitting phosphor for white light emitting diode (w-LED) application.