Effect of the Pr3+ → Gd3+ energy transfer in multicomponent garnet single crystal scintillators

Luminescence processes in the undoped and Pr3+-doped (Gd,RE)(3)(Ga,Al)(5)O-12, RE = Lu,Y, multicomponent garnets are studied by time-resolved photoluminescence spectroscopy. Energy transfer processes between Pr3+ and Gd3+ causing significant deterioration of the scintillation performance are considered in detail. As is shown in current work, an overlap of the 5d(1)-H-3(4) emission transition of Pr3+ and S-8-P-6(x) absorption transition of Gd3+ results in unwanted depletion of Pr3+ 5d(1) excited state and is further intensified by the concentration quenching in the Gd3+-sublattice. This process explains a drastic decrease of light yield in Pr3+-doped Gd3+-containing multicomponent garnets observed in a previous work.