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Codoping is a method of current interest for modifying the properties of scintillators. The study reported here explores the effect of codoping on cerium doped Gd 3 Ga 3 Al 2 O 12 (GGAG:Ce) crystals with various concentrations of Ca. These single crystals were grown via the Czochralski technique with Ce concentrations fixed at 0.2 at% and Ca concentrations ranging from 0.1 at% to 0.4 at% in the initial melt. The relationship between dopant concentration and light yield, rise time, and scintillation and photoluminescence decay times was determined. In addition, the absorbance, photoluminescence, radioluminescence, afterglow and thermoluminescence dependence on the dopant concentration are presented. In some of the Ca codoped crystals, an additional luminescence center was observed with an excitation wavelength of 350 nm and an emission wavelength of 400 nm and a photoluminescence decay time of ~3.5 ns. [ABSTRACT FROM AUTHOR]

In this study, we demonstrated a drastic improvement in energy resolution of (Lu0.75Y0.25)3Al5O12:Pr (LuYAG) single crystal scintillators from 4.8% to 4.1% at 662 keV upon Li+ codoping, which is the best value ever reported in the class of oxide single crystal scintillators. Li+ codoping can also significantly enhance its scintillation yield from 16 000 to 25 000 photons MeV−1, but slightly prolong the scintillation decay time. As Li+ codoping was found to have a negligible effect on the light yield non‐proportionality, we attributed the significant improvement in energy resolution to the reduced statistical variance in the number of photoelectrons produced in the photomultiplier tube (Rstat). [ABSTRACT FROM AUTHOR]