Effect of codoping on scintillation and optical properties of a Ce-doped Gd3Ga3Al2O12 scintillator

Single crystals of Gd3Ga3Al2O12 : Ce with different codopants were successfully grown using the Czochralski technique. Optical and scintillation properties of these codoped crystals were studied in detail including absorption, photoluminescence excitation and emission, decay time and thermoluminescence. This study revealed that while boron codoping improves the scintillation light output and energy resolution and decreases self-absorption in these crystals, calcium codoping affects their properties in the opposite manner. In addition to antisite defects, the effect of room temperature trap centres on the sensitivity of these crystals to light exposure is also reported for the first time. Light sensitivity was also found to be affected with the incorporation of codopants in the lattice. The effect of annealing in oxidizing and reducing atmospheres on the scintillation and optical properties of differently codoped crystals was also investigated in detail in order to better understand the defect structure of these crystals. All these measurements together are used to explain the effect of codoping on the crystal field and defect structure of these crystals.