Ultrafast preparation of amine-free 0D metal halides with near-unity emission for X-ray scintillators

Zero-dimensional (0D) metal halides are promising candidates for next-generation scintillators due to their efficient broadband emission from self-trapped excitons (STEs) and substantial X-ray attenuation coefficients. However, their practical implementation is constrained by conventional synthetic methods that generally require extended reaction durations, energy-intensive conditions, and incorporation of organic amines, leading to elevated costs and scalability issues. Herein, we demonstrate an ultrafast preparation of amine-free 0D metal halides, exemplified by Al(DMSO)₆[SbCl₆], synthesized at room temperature under ambient atmosphere within seconds. This method achieves gram-scale production with a yield of 96.3% and near-complete atom economy. The obtained material exhibits efficient STE emission with a near-unity photoluminescence quantum yield (PLQY) of 97.65% upon 330 nm excitation, featuring a broad emission band centered at 515 nm with a Stokes shift of 185 nm. As an X-ray scintillator, it demonstrates a high light yield of 11 539 photons per MeV and a low detection limit of 3.81 μGy s^-1 and maintains over 98% intensity retention after 20 irradiation cycles. Additionally, a PDMS-composite film facilitates high-resolution X-ray imaging with a spatial resolution of 9.3 lp mm^-1. This work establishes an efficient synthesis strategy for amine-free metal halides with near-unity emission, advancing their application in radiation detection.