Thermally Activated Delayed Fluorescence Zirconium‐Based Perovskites for Large‐Area and Ultraflexible X‐ray Scintillator Screens

Flexible scintillator screens with environmental stability, high sensitivity, and low cost have emerged as candidates for X-ray imaging applications. Here, a large-scale and cost-efficient solution synthesis of the vacancy-ordered double perovskite Cs₂ ZrCl₆ , which is characterized by thermal activation delayed fluorescence (TADF) dominated by triplet emission under X-ray irradiation, is demonstrated. The large Stokes shift and efficient luminescence collection of TADF effectively ensure the light outcoupling efficiency. Further, flexible X-ray scintillator screens with an area of 400 cm² are prepared using poly(dimethylsiloxane) (PDMS) as the carrier, exhibiting excellent scintillation properties with light yields as high as 49 400 photons MeV⁻¹ , spatial resolutions up to 18 lp mm⁻¹ and detection limits as low as 65 nGy s⁻¹ . Finally, the high-quality imaging results of non-planar and dynamic objects by such screens are demonstrated. It is believed that the explored Cs₂ ZrCl₆ @PDMS flexible scintillator screens would offer a big step toward expanding the application range of scintillators in different environments.