A novel blue-emitting silica-coated KBaPO4:Eu2+ phosphor under vacuum ultraviolet and ultraviolet excitation

An intense blue-emitting phosphor KBaPO4:Eu2+ was synthesized by a solid-state reaction method. The crystal structure of KBaPO4:Eu2+ was refined using neutron diffraction data by Rietveld refinement for the first time. KBa0.99Eu0.01PO4 composition shows intense blue emission (peak wavelength, 420 nm) with relative intensity vs commercial BaMgAl10O17:Eu2+ blue phosphor (Nichia) 65%, 122% and 108% under 147, 254 and 365 nm excitation, respectively. In addition, by applying a nano-sized silica coating on the phosphor surface, excellent moisture resistance of KBP:Eu2+ was obtained. Due to its intense blue emission and excellent color purity (0.1606, 0.0271), it is very potent as a blue-emitting phosphor for PDPs, CCFLs, and pc-white LEDs based on near UV LED.