Luminescence and scintillation mechanism in Ce3+ and Pr3+ doped (Lu,Y,Gd)3(Ga,Al)5O12 single crystal scintillators



Luminescence processes occurring in the 5d1 excited state of Ce3+ and Pr3+ centers in the (Gd,RE)3(Ga,Al)5O12, RE=Lu,Y, multicomponent garnet host were studied by purely optical contactless methods. Combination of measurements of the prompt nanosecond decay and slow delayed radiative recombination decay allows to resolve the presence of thermal quenching and thermally induced ionization processes acting upon the 5d1 excited state. Additional energy transfer process depleting the 5d1 state of Pr3+ center was found and is due to the resonance of 5d1-3H4 emission transition of Pr3+ and 8S-6Px absorption transition of Gd3+ which might be responsible for noticeably lower light yield in Pr-doped multicomponent garnets. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)