Blue-emitting long-lasting phosphor, Sr3Al10SiO20:Eu2+,Ho3+

A novel blue-emitting long-lasting phosphor Sr3Al10SiO20:Eu2+,Ho3+ is prepared by the conventional high-temperature solid-state technique and their luminescent properties are investigated. XRD, photoluminescence (PL) and thermoluminescence (TL) are used to characterize the synthesized phosphors. These phosphors are well crystallized by calcinations at 1500-1600 °C for 3 h. The phosphor emits blue light and shows long-lasting phosphorescence after it is excited with 254/365 nm ultraviolet light. TL curves reveal the introduction of Ho3+ ions into the Sr3Al10SiO20:Eu2+ host produces a highly dense trap level at appropriate depth, which is the origin of the long-lasting phosphorescence in this kind of material. The long-lasting phosphorescence lasts for nearly 6 h in the light perception of the dark-adapted human eye (0.32 mcd/m2). All the results indicate that this phosphor has promising potential practical applications.