Surface Modified\nCsPbBr<sub>3</sub> Nanocrystals Enable\nFree Radical Thermal Polymerization of Efficient Ultrafast Polystyrenic\nNanocomposite Scintillators

Lead\nhalide perovskite nanocrystals (LHP-NCs) embedded\nin a plastic\nmatrix are highly promising for a variety of photonic technologies\nand are quickly gaining attention as ultrafast, radiation-resistant\nnanoscintillators for radiation detection. However, advancements in\nLHP-NC-based photonics are hindered by their well-known thermal instability,\nwhich makes them unsuitable for industrial thermally activated mass\npolymerization processes, crucial for creating polystyrene-based scintillating\nnanocomposites. In this study, we address this challenge by presenting\nthe first thermal nanocomposite scintillators made from CsPbBr<sub>3</sub> NCs passivated with fluorinated ligands that remain attached\nto the particles surfaces even at high temperatures, enabling their\nintegration into mass-cured polyvinyl toluene without compromising\noptical properties. Consequently, these nanocomposites demonstrate\nscintillation light yields reaching 10 400 photons/MeV, subnanosecond\nscintillation kinetics, and remarkable radiation resilience, able\nto withstand γ radiation doses of up to 1 MGy. This performance\nnot only meets but also exceeds the scintillation of plastic scintillators\ndespite the radiation-induced damage to the host matrix.