Near‐Infrared Emitting Rare‐Earth Doped Perovskite Scintillator for X‐Ray Flexible Imaging

ABSTRACT High‐performance X‐ray scintillation detectors are crucial for X‐ray imaging applications, relying on scintillators with high light‐yield (LY). In contrast to conventional scintillators with large bandgaps ( E g ), halide perovskite materials with low E g exhibit high LY, emerging as next‐generation scintillation materials. Additionally, doping with rare‐earth ions extends the emission wavelength to the near‐infrared (NIR) region, effectively suppressing light self‐absorption of perovskite materials. Here, we fabricated a Ytterbium‐ion (Yb 3+ ) doped CsPbCl 3 : 2%Yb 3+ single crystal (SC) with a large‐size of Φ30 × 40 mm via the Bridgman method, which exhibits a low E g of 2.88 eV and efficient NIR luminescence centered at 985 nm, achieves a high steady state LY of 83 703 photons MeV −1 , and a large effective “Stokes shift” of 563 nm. Furthermore, we prepare a series of flexible scintillation films by embedding CsPbCl 3 : 2%Yb 3+ powder in polydimethylsiloxane (PDMS). Owing to the efficient NIR luminescence, these films enable clear X‐ray imaging even under bright white‐LED interference, demonstrating a low X‐ray detection limit of 17.8 nGy air s −1 and a high spatial resolution of 10 lp mm −1 . This work provides a high‐LY NIR scintillator for X‐ray flexible imaging, paving the way for low dose‐rate X‐ray imaging for portable and fast radiography.