Melt‐Processing Enabled Flexible Metal Halide‐Nylon Luminescent Films with Enhanced Optical Transmission for Curved X‐Ray Imaging

Abstract Organic–inorganic hybrid metal halides are emerging as a class of functional materials that combine attractive photophysical properties with great processability. Their modular chemical structures allow for melt processing through crystal‐melt transitions. Herein, the study reports the synthesis of (Bzmim)₂MnX₄ (Bzmim = 1‐benzyl‐3‐methylimidazolium, X = Cl, Br, I) single crystals with low melting temperatures ranging from 130 to 160 °C. Among them, (Bzmim)₂MnBr₄ exhibits superior luminescence performance with a photoluminescence quantum yield of 78.6% and a light yield of 34 900 photons MeV⁻¹, making it act as a promising scintillator. Interestingly, leveraging the melt fluidity and the porous structure of nylon film, a transparent crystalline (Bzmim)₂MnBr₄‐Nylon composite film is fabricated by the melt‐infiltration process. Compared to the nylon film, the composite film has an increased light transmittance from ≈20% to >60%. It can be attributed to uniform melt crystallization in the pores of nylon film, which suppresses severe light crosstalk caused by the large refractive index difference at the nylon‐air interface. The melt‐processable transparent composite film exhibits a spatial resolution of 16 line pairs per millimeter in practical X‐ray imaging, as well as promising applications in curved X‐ray imaging due to its great flexibility.