Study on long-lasting phosphorescent mechanism of Tb3+ doped ZnO-B2O3-SiO2 glass

Tb3+ doped ZnO-B2O3-SiO2(ZBS) glass was prepared by conventional melt-quenched method. The long-lasting phosphorescent mechanism of this kind of glass was systematically analyzed by fluorescent spectra, afterglow decay curves, glow curves, UV-visible spectra etc. The Half Tunneling model of the long-lasting phosphorescence was also established by related mechanism. This model of mechanism indicated that the long-lasting phosphorescence of Tb3+ doped ZBS glass only has a connection with the traps of shallow energy, and that the different traps in energy level depth correspond with different processes of afterglow decay. It also demonstrated that the excited electrons are ultimately captured by traps through conduction band, and that the electrons run away from traps tunnel into luminescent ions through 5d energy band.