Long Lasting Phosphorescence in Mn<sup>2+</sup>-Activeted ZnO-B<sub>2</sub>O<sub>3</sub> Glass

Abstract

Mn2+ activated ZnO-B2O3 glasses show bright and long-lasting phosphorescence (LLP). After irradiation by 254nm light, a visible red light with dominating peak at 600nm can be observed with the naked eye in the dark for up to 12h after removal of the activating light. We examined the luminescence properties using fluorescence, phosphorescence spectra and thermostimulated luminescence (TL). This phosphorescence arises from d-d transitions of Mn2+ ions. The thermostimulated luminescence (TL) intensity increases with the increasing of Mn2+ concentration from 1×10-3 mol % to 1×10-1 mol %. The decay curve of the LLP is consistent with the TL releasing velocity raised from defects of 420K. Based on the fact, we suggest that LLP is a special kind of thermostimulate luminescence. The storage and releasing of energy is closely associated with properties of defects, while the properties of LLP are related to both the defects and luminescence centers.