Synergistic High-Z Bismuth and Eu3+ Activators in a Metal–Organic Framework for Efficient X-Ray and β-Ray Scintillation

Comprehensive Summary Radiation scintillators that combine high sensitivity, stability, and multimodal detection capability are highly desirable for advanced radiation imaging and monitoring. Herein, we report a rational lanthanide-doping strategy to construct a high-performance metal–organic framework (MOF) scintillator, namely Eu 3+ ⊂Bi-ndc . In this design, high-atomic-number Bi 3+ nodes serve as efficient X-ray absorbers, while Eu 3+ ions act as isolated luminescent activators, and rigid 2,6-naphthalenedicarboxylate (ndc 2– ) ligands function as effective antennae to facilitate energy transfer and suppress non-radiative relaxation. Under X-ray excitation, Eu 3+ ⊂Bi-ndc shows intense radioluminescence with a low detection limit of 2.5 μGy·s –1 , a light yield of 25,695 photons MeV –1 , and outstanding irradiation stability. Flexible scintillating films fabricated from Eu 3+ ⊂Bi-ndc enable high-resolution X-ray imaging with a spatial resolution of approximately 7 lp·mm –1 . Remarkably, Eu 3+ ⊂Bi-ndc also exhibits measurable β-ray–induced scintillation, representing the first example of a lanthanide-containing MOF functioning as a β-ray scintillator. This study advances a synergistic high- Z /lanthanide MOF paradigm that bridges X-ray and β-ray scintillation, paving the way for novel multifunctional radiation detectors.