Nanocrystal Quality–Controlled Scintillation in Porous YAG:Ce Aerogels

ABSTRACT The development of porous scintillators is an emerging field for the detection of pure beta emitters in gas, as well as for long‐lived, low‐power batteries and implantable therapeutic emitting devices. Achieving large‐area, efficient, and transparent porous scintillators for these applications requires precise control over nanoscintillator parameters and the architecture of the functional material. Aerogels composed of nanoscintillators currently represent the most promising fabrication route, enabling the production of large, translucent structures. However, while optical transparency favors the smallest nanoparticles, optimal scintillation performance generally requires larger, well‐crystallized particles with minimal defects. In this work, we investigate the light yield and scintillation mechanisms of YAG:Ce aerogels as a function of synthesis and post‐treatment conditions. Our results show that high‐temperature thermal treatment enhances light output under ionizing radiation by a factor of eight, without modifying timing performance. We further demonstrate the extreme sensitivity–and reversibility–of low‐temperature atmospheric treatments on the oxidation state of cerium ions. These findings provide new insight into the role of defects in nanoscintillators and open pathways toward the development of more efficient porous scintillator materials.