| 摘要 |
Provided is a light-accumulating phosphor having high afterglow luminance. This light-accumulating phosphor comprises a compound represented by MAl2O4, with the metal element represented by M being composed of Sr, Mg and Ba, as a host crystal, and contains Eu as an activator, while containing Dy as a coactivator. The Eu content satisfies 0.001 ≤ Eu/(M + Eu + Dy) ≤ 0.05 in terms of a molar ratio; the Dy content satisfies 0.004 ≤ Dy/(M + Eu + Dy) ≤ 0.06 in terms of a molar ratio; the Mg content satisfies 0.02 ≤ Mg/(M + Eu + Dy) ≤ 0.1 in terms of a molar ratio; and the Ba content satisfies 0.03 ≤ Ba/(M + Eu + Dy) ≤ 0.15 in terms of a molar ratio. In addition, this light-accumulating phosphor contains at least one alkali metal element selected from the group consisting of Li, Na, K and Rb. This excellent light-accumulating phosphor achieves high afterglow luminance by containing Mg, Ba and the alkali metal element(s) at the same time. |
