[17p-C102-1~12] Novel physical properties and applications of ternary compounds

[17p-C102-2] Probing trapped electron centers in phosphor materials using infrared light

〇Mamoru Kitaura¹ (1.Yamagata Univ.)

Keywords:multicomponent garnet oxides, phosphors, infrared spectroscopy

Garnets have been widely used as phosphors such as white-LEDs, solid-state lasers, and scintillators. The crystal of Gd3Al2Ga3O12 (GAGG) is one of multi-component garnets, which has been recently applied to scintillation detectors. The light output and decay time are crucial for scintillator application. In order to improve these properties, it is nescessary to clarify the origin of lattice imperfections. The information obtained will be connetcted to exprore the methods to suppress the lattice imperfections acting as photocarrier traps. So far, we have studied the origin of electron traps formed in UV-irradiated GAGG crystals. The electron trap forms a shallow level below the conduction band. The trap depth was estimated atound 0.25 eV, being agreement with the photon energy in infrared region. Therefore, it is natural to investigate the nature of trapped electron centers using infrared spectroscopy. The results for GAGG:Ce crystals using synchrotron radiation and free electron laser will be exhibited in this presentation.