A study on the chromaticity shifts of blue phosphor for color plasma displays

Abstract

Abstract— The dependency of the chromaticity shifts on the concentration of Eu 2+ doped in BaMgAl 10 O 17 (BAM) was investigated under heat‐treatment and vacuum ultraviolet (VUV) irradiation. The Eu 2+ 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 Eu 2+ 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 Eu 2+ ions in different sites in a BAM lattice results in different chromaticity coordinates. By increasing the Eu 2+ concentration in BAM, or under heat‐treatment and VUV irradiation, the emission band shifts towards longer wavelengths.