Lead-free X-ray imaging scintillators based on zero-dimensional manganese hybrid metal halide

X-ray imaging holds great significance in medical applications, security screening, and non-destructive testing. Metal halide with exceptional luminescent properties have emerged as promising materials for X-ray detection and imaging are emerging. However, the widespread application of Pb²⁺ is limited due to its toxic nature. In this work, a new of lead-free zero-dimensional manganese hybrid metal halide (C₁₉H₁₈P)₂MnBr₄ has been synthesized by inserting (C₁₉H₁₈P)⁺ into [MnBr₄]²⁻ tetrahedrons lattice through a facile antisolvent assisted crystallization method in room temperature. The results of the study indicate that (C₁₉H₁₈P)₂MnBr₄ possesses a typical tetrahedral coordination structure associated with d-d transition, resulting in a highly intense green emission at 508 nm characterized by its narrow-band nature [a full width at half maximum (FWHM) of 50 nm]. (C₁₉H₁₈P)₂MnBr₄ exhibits high photoluminescence quantum yields (PLQYs) of 90.1 %, high and steady-state X-ray light yield of 44,000 photons MeV⁻¹, and relative short RL decay time (146 μs) which is shorter than those manganese halides ever reported. Finally, X-ray imaging measurement was performed using (C₁₉H₁₈P)₂MnBr₄ polyacrylonitrile (PAN) composite film as a scintillation screen, which exhibited distinct visuals of items when exposed to X-ray radiation irradiation. The spatial resolution was determined to be 12.6 line pairs per millimeter (lp mm⁻¹) at a modulation transfer function (MTF) of 0.2 for (C₁₉H₁₈P)₂MnBr₄/PAN composite scintillation screen. (C₁₉H₁₈P)₂MnBr₄ scintillators possess environmentally friendly characteristics and can be easily synthesized. Therefore, (C₁₉H₁₈P)₂MnBr₄ demonstrates immense potential as the next generation of scintillators, while this study presents an innovative approach for the cost-effective preparation of metal halide scintillators.