Temperature-Dependent Long-Lasting Phosphorescence in SrSi2O2N2:Eu2

Yellow-light-emitting phosphor SrSi2O2N2:Eu2+ was synthesized by using a simple solid-state reaction method with Sr2SiO4:Eu2+ as the precursor. This phosphor was found to be well-crystallized by utilizing XRD. Luminescence and afterglow properties of it have been systematically investigated. After 15 minutes excitation with an unfiltered xenon arc lamp at 1000 lux, its afterglow can be seen for more than 2.5 h in the limit of light perception of dark-adapted human eyes (0.32 mcd/m2). Furthermore, its temperature-dependent long-lasting phosphorescence (LLP) characteristic was investigated for the first time, combining information from thermoluminescence (TL) spectrum, a possible mechanism for the LLP of SrSi2O2N2:Eu2+ phosphor was discussed in this paper.