Ba5SiO4Cl6:Eu2+: An intense blue emission phosphor under vacuum ultraviolet and near-ultraviolet excitation

An intense blue emission of Eu2+-doped Ba5SiO4Cl6 under vacuum ultraviolet and near-ultraviolet excitation was observed. The material exhibits an emission peak at 440 nm with relative intensity 50% under 147 nm, 90% under 254 nm, 120% under 366 nm, and 220% under 405 nm excitation as compared with the commercial blue phosphor BaMgAl10O17:Eu2+. It is a very promising candidate as a blue-emitting phosphor for potential applications in display and light-emitting diode devices.