Hydrothermal preparation and persistence characteristics of nanosized phosphor SrS: Eu2+, Dy3+

Nanosized long-persistent phosphors SrS: Eu2+, Dy3+ were prepared by the hydrothermal method. The samples were characterized by X-ray powder diffraction, transmission electron microscopy, and charge-coupled device spectrometry. The persistence characteristic was studied using the decay curves. The results showed that the emission intensity decreased sharply with temperature increasing, although the particle size increased. The S2– vacancies caused by oxidization served as shallow traps, and Dy3+ served as deep traps in SrS: Eu2+, Dy3+. The afterglow intensity of SrS: Eu2+, Dy3+ was higher than that of SrS: Eu2+ prepared at the same temperature. However, the minimization span of initial afterglow with temperature for the former sample was larger than that for the latter. Binary-doped phosphor decayed more slowly than the singly doped one. The afterglow of SrS: Eu2+, Dy3+ decayed more quickly with the increase of sintering temperature.