Effect of Isovalent and Heterovalent Substitution on Scintillation Properties of LYSO:Ce Single Crystals

The rational design of high-performance oxide scintillators, such as LYSO:Ce, is hindered by an incomplete understanding of their complex scintillation mechanisms. Here, we introduce a strategy of isovalent (Ge4+) and heterovalent (Al3+, P5+) codoping to precisely control the defect structure and scintillation properties. This work uncovers how different codoping strategies distinctly modulate performance. Isovalent Ge4+ codoping synergistically enhances light yield by suppressing deep electron traps and improving thermal stability. In contrast, heterovalent substitutions create a complex interplay to accelerate decay kinetics: while both effectively suppress slow Ce2 emission, they rely on distinct additional pathways─Ce4+ stabilization for Al3+ versus enhanced thermal quenching for P5+. Critically, this comparative study establishes that the suppression of deep electron traps is the dominant factor driving the light yield increase, an effect potent enough to overcome efficiency losses from thermal quenching (as seen in Al3+ codoping). These findings offer novel physical insights and a potent strategy for designing advanced oxide scintillators, paving the way for next-generation ultrafast radiation detection.