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 Ba5SiO4Cl6: Eu2+ 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 BaMgAl10O17: Eu2+ blue phosphor, the as-obtained Ba5SiO4Cl6: Eu2+ phosphor displays a narrower band blue emission (λem = 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 Ba4.98Eu0.02SiO4Cl6 phosphors was estimated to be as high as 57.2%. Finally, a LED device coupling UV-chip (400 nm) with Ba5SiO4Cl6: Eu2+, (Sr, Ba)2SiO4: Eu2+, (Sr, Ca)AlSiN3: Eu2+ 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 Ba5SiO4Cl6: Eu2+ phosphor will be a market prospect phosphor for the application of lighting and display.