Ultra-narrow band blue-emitting Ba5SiO4Cl6: Eu2+ phosphors with excellent thermal stability

The narrow band phosphors with excellent thermal stability have received growing attention from academic and industrial researchers. In this work, a novel Ba 5 SiO 4 Cl 6 : Eu 2+ phosphor was prepared via solid phase reaction. Their crystal structure, phase composition, morphology and optical performance containing photoluminescence (PL) emission, PL excitation and temperature-dependence PL spectra were systematically analyzed. Compared with commercial BaMgAl 10 O 17 : Eu 2+ blue phosphor, the as-obtained Ba 5 SiO 4 Cl 6 : Eu 2+ phosphor displays a narrower band blue emission ( λ em  = 440 nm) with a full width at half maximum of 32 nm under the near ultraviolet light excitation and an excellent thermal stability for 83.3% of the initial intensity at 150 °C. The quantum yield of the Ba 4.98 Eu 0.02 SiO 4 Cl 6 phosphors was estimated to be as high as 57.2%. Finally, a LED device coupling UV-chip (400 nm) with Ba 5 SiO 4 Cl 6 : Eu 2+ , (Sr, Ba) 2 SiO 4 : Eu 2+ , (Sr, Ca)AlSiN 3 : Eu 2+ phosphors display attractive optical performance with LE = 45 lm/W, CCT = 3407 K and Ra = 94. Therefore, there are good reasons for believing that the Ba 5 SiO 4 Cl 6 : Eu 2+ phosphor will be a market prospect phosphor for the application of lighting and display.