The Effect of Codoping on Pulse-Shape Discrimination Properties of Gd₃Ga₃Al₂O₁₂:Ce Single Crystals

In this article, we have extended our study on the effect of codopants on the scintillation properties of Ce-doped Gd₃Ga₃ Al₂O₁₂(GGAG:Ce) single crystals by investigating their pulse-shape discrimination (PSD) abilities. The GGAG:Ce crystals were grown with boron and calcium codopants using the Czochralski technique. The codoping was found to have substantial effects on the PSD ability of these scintillators. Observable difference in the pulse shapes for alpha and gamma radiations in the B-codoped GGAG:Ce scintillators exhibited the highest PSD, while those with Ca codoping showed no discrimination among the studied samples despite having a significant effect on the scintillation kinetics and a strong quenching of the light yield by alpha radiations that resulted in a minimum alpha gamma ratio. A correlation of the PSD properties with the defect structure of these single crystals has been made by using optically stimulated luminescence (OSL) for the first time. OSL studies with infrared, blue, and green light provided an insight into the role of defect centers in the relaxation mechanism of the scintillation kinetics of the GGAG:Ce crystals, which subsequently affects their ability to discriminate different kinds of radiation.