A Thermo‐Responsive MOFs for X‐Ray Scintillator

Abstract Thermo‐responsive smart materials have aroused extensive interest due to the particular significance of temperature sensing. Although various photoluminescent materials are explored in thermal detection, it is not applicable enough in X‐ray radiation environment where the accuracy and reliability will be influenced. Here, a strategy is proposed by introducing the concept of radio‐luminescent functional building units (RBUs) to construct thermo‐responsive lanthanide metal‐organic frameworks (Ln‐MOFs) scintillators for self‐calibrating thermometry. The rational designs of RBUs (including organic ligand and Tb³⁺/Eu³⁺) with appropriate energy levels lead to high‐performance radio‐luminescence. Ln‐MOFs scintillators exhibit perfect linear response to X‐ray, presenting low dose rate detection limit (min ≈156.1 nGy_airs^‐1). Self‐calibrating detection based on ratiometric XEL intensities is achieved with good absolute and relative sensitivities of 6.74 and 8.1%K^‐1, respectively. High relative light yield (max ≈39000 photons MeV⁻¹), imaging spatial resolution (max ≈18 lp mm^‐1), irradiation stability (intensity ≈100% at 368 K in total dose up to 215 Gy_air), and giant color transformation visualization benefit the applications, especially the in situ thermo‐responsive X‐ray imaging. Such strategy provides a promising way to develop the novel smart photonic materials with excellent scintillator performances.