Scaling Up Purcell‐Enhanced Self‐Assembled Nanoplasmonic Perovskite Scintillators into the Bulk Regime

Abstract Scintillators convert high‐energy radiation into detectable photons and play a crucial role in medical imaging and security applications. The enhancement of scintillator performance through nanophotonics and nanoplasmonics, specifically using the Purcell effect, has shown promise but has so far been limited to ultrathin scintillator films because of the localized nature of this effect. This study introduces a method to expand the application of nanoplasmonic scintillators to the bulk regime. By integrating 100‐nm‐sized plasmonic spheroid and cuboid nanoparticles with perovskite scintillator nanocrystals, nanoplasmonic scintillators are enabled to function effectively within bulk‐scale devices. Power and decay rate enhancements of up to (3.20 ± 0.20) and (4.20 ± 0.31) folds are experimentally demonstrated for plasmonic spheroid and cuboid nanoparticles, respectively, in a 5‐mm thick CsPbBr 3 nanocrystal‐polymer scintillator at RT. Theoretical modeling also predicts similar enhancements of up to (2.26 ± 0.31) and (3.02 ± 0.69) folds for the same nanoparticle shapes and dimensions. Moreover, a (2.07 ± 0.39) fold increase in light yield under 241 Am γ‐excitation is demonstrated. These findings provide a viable pathway for utilizing nanoplasmonics to enhance bulk scintillator devices, advancing radiation detection technology.