Influence of Self-Absorption and Impurities on Scintillation Properties of (Lu_0.1Y_0.9)AlO₃:Ce Single Crystals

Lu_0.1Y_0.9AlO₃:Ce single crystals in dimensions ∅30×90mm³ are successfully grown by the Czochralski method. The light output and energy resolution of the crystal in dimensions ∅14×2mm³ are 9420 photons/MeV and 12.5% respectively. Dependence of the light output on the thickness of the sample is found and explained by the self-absorption in the range of 320--370nm and the underlying parasitic absorption around 250nm. In addition, the local enrichment of Ce ions and the presence of low-valent impurity ions may cause the deterioration of its light output. In addition, Lu_0.1Y_0.9AlO₃:Ce has an almost constant fluorescence decay time of 16ns in the temperature range of 80--373K.