Highly luminescent organic-inorganic hybrid antimony halide scintillators for real-time dynamic and 3D X-ray imaging

Real-time dynamic and three-dimensional (3D) X-ray imaging are the most challenging types of X-ray imaging technology, placing more rigorous standards on scintillators. Lead-based (Pb²⁺) organic-inorganic hybrid halide (OIHH) scintillators with high X-ray absorption coefficients have been demonstrated to exhibit excellent scintillation performance. However, their toxicity and instability hindered further development, and it is necessary to explore novel low-toxic metal-based OIHHs possessing excellent scintillation performance. Antimony-based (Sb³⁺) OIHHs are not only environmentally friendly, but also show good stability compared to Pb²⁺-based OIHHs, which make them promising candidates as excellent scintillators. Currently, the understanding of Sb³⁺-based OIHH scintillators for X-ray detection and imaging is still in infancy and requires further exploration. Herein, we designed two Sb³⁺-based OIHH crystals of (BPP)₂SbCl₅ (CP1) and (BPP)₂SbCl₅ 0.5 H₂O (CP2), which have very similar crystal structures except the introduction of water molecules in CP2. Experimental and theoretical results reveal that CP2 has larger lattice distortion and smaller freedom of motion, which can promote the self-trapped excitons emissions. A flexible scintillator screen based on CP2 crystals was prepared and applied for real-time dynamic and 3D X-ray imaging, which is the first time for Sb³⁺-based OIHH scintillators and significantly broadens the potential of Sb³⁺-based OIHH scintillators.