Long-lasting phosphorescence in Ce-doped oxides

Although oxide crystals doped with Ce3+ are not useful in laser operation, they have advantage in the areas such as scintillators and passive optical sources. Scintillator materials require high light-yield and fast fluorescence decay time. However, when the crystalline quality is degraded by defects created during the crystal growth process, afterglow from the crystals is observable persistently. Such phosphorescence is undesirable for scintillators, but useful in passive optical sources. The phosphorescence observed in Ca2Al2SiO7 doped with Ce3+ ions has been investigated in detail and a model is proposed to explain the mechanism responsible