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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.

Abstract— The dependency of the chromaticity shifts on the concentration of Eu2+ doped in BaMgAl10O17 (BAM) was investigated under heat‐treatment and vacuum ultraviolet (VUV) irradiation. The Eu2+ ions in BAM show an asymmetrical broad emission band with a maximum at ∼452 nm under excitation of VUV light at room temperature, showing that multiple crystalline cationic sites exist in the host. It was found that the chromaticity shifts greatly decrease with increasing heat‐treatment temperature. Regardless of the Eu2+ concentration, the chromaticity shifts caused by heat‐treatment are greater than that caused by VUV irradiation. Compared with conventional BAM, a solid solution of BAM with barium aluminate as a powder and film was also studied, and very few chromacity shifts were observed. It is suggested that the distribution of Eu2+ ions in different sites in a BAM lattice results in different chromaticity coordinates. By increasing the Eu2+ concentration in BAM, or under heat‐treatment and VUV irradiation, the emission band shifts towards longer wavelengths.

The luminescence properties of blue phosphors 0.9BaOÁ0.1EuOÁMgOÁmAl 2 O 3 with m ¼ 3:5 to 8.0 were investigated for color plasma display panel (PDP) applications. The deterioration properties of the phosphors baked in air and irradiated under vacuum ultraviolet (VUV) rays were systematically studied with different alumina contents m. The results indicate that the phosphor with m ¼ 5:0 shows a relatively more stable color chromaticity after the baking process and VUV irradiation, whereas the phosphors with m ¼ 5:5 to 8.0 show small decreases in the emission intensity compared to the phosphor with m ¼ 5:0 after VUV irradiation. These decreases in the emission efficiency are ascribed to the irregular order of the Eu 2þ ions in the intermediate layer and the shifts of the chromaticity coordinates to the changes of the Eu 2þ sites, which are suggested to occupy unstable Beevers-Ross and/or mid-oxygen sites in the host.