Growth and scintillation properties of Sc, Pr, Ce co-doped LuAG epitaxial garnet layers

Abstract

Single crystalline Sc, Pr, Ce co-doped Lu3Al5O12 garnet layers were grown by liquid phase epitaxy. The Sc doping increases the scintillation response of Pr3+ activator ions because of overlap of the Sc-related emission around 275 nm with the 4f→5d absorption band of Pr3+ centers. The radioluminescence (RL) spectra give evidence for presumed energy transfer form Sc3+ to Pr3+ activator ions. Significant increase of the RL emission output was observed when co-doping with both Pr and Sc ions compared to Sc-free samples. The maximum integral RL was noticed for samples with relatively high Sc concentration, 1.2 - 3 at %. On the contrary, an increase of the photoelectron yield, Nphe, measured under alpha particle excitation, was observed only for rather low Sc content, ∼0.6 at %, at higher Sc concentrations Nphe decreased. Nevertheless, LuAG epitaxial layers with optimal Sc and Pr contents show comparable or even a bit higher Nphe yield and energy resolution than Cz-grown Pr:LuAG single crystals. Furthermore, the slow components in photoelectron response were significantly suppressed in epitaxial layers compared to single crystals.