Investigation of Optical Properties of Ceramic Ce:GAGG by High Temperature Annealing

An as-fabricated cerium-doped ceramic scintillator Gd3Al2Ga3O12 (Ce:GAGG) was thermally annealed at different temperatures. The light output and energy resolution of the scintillators were measured before and after thermal treatment. The effect of thermal annealing in the air at high temperature (at 1000 degrees C for 5 hours) deforms the microstructure by mitigating oxygen vacancies of the ceramic scintillator. This has been proven by XPS study that showed the existence of oxygen vacancies and subsequent decrease of oxygen deficiency amid annealing treatment that led to an output signal increase. The diffusion ability of oxygen atoms by annealing played a key role in compensating for defect sites. In this study, by controlling thermodynamic conditions, the light output was enhanced by similar to 30.4% and the energy resolution improved by similar to 2.4% after annealing at 1000 degrees C in the air.