Exciton Diffusion‐Suppressed Scintillator for Ultrafast and High‐Resolution Radiography

Organic‐inorganic hybrid scintillator PEA 2 PbBr 4 has emerged as a promising fast scintillator for applications in ultrafast radiation imaging, transient diagnosis of pulsed radiation fields, and medical radiodiagnosis. However, its performance is limited by notably prolonged decay times under high‐energy X‐ray excitation due to inefficient radiative recombination of sparsely distributed bulk excitons. Furthermore, the difficulty in growing and processing high‐quality, large‐area single crystals hinders the development of scalable scintillation screens. Here, we report a general fabrication strategy for large‐area uniform scintillation screens that synergistically enhances the decay time and imaging resolution under X‐ray excitation by suppressing bulk exciton diffusion in PEA 2 PbBr 4 . By leveraging the spatial confinement of nano‐porous templates, we reduce the dimensionality of PEA 2 PbBr 4 from bulk single crystals to uniform 1D nanowires, leading to spatial localization of bulk excitons. This localization significantly shortens the radioluminescence decay time from 11.85 to 1.87 ns. Meanwhile, the regularly aligned periodic optical waveguide structure enables directional propagation of scintillation photons along the nanowires, yielding high spatial resolution imaging (57.1 lp/mm at MTF = 0.2). This work provides a viable approach for advancing the application of organic‐inorganic hybrid scintillators in ultrafast radiation imaging.