Enhanced X-ray luminescence in one-dimensional Cu–I coordination polymers via ligand halogen engineering

Cu(I) halide-based scintillators are emerging as eco-friendly alternatives to traditional X-ray imaging scintillators because of their high luminescence efficiency and solution processability. Although much progress has been made in zero-dimensional (0D) Cu–I cluster scintillators, there has been limited focus on one-dimensional (1D) Cu–I coordination polymers because of their lower luminescence efficiencies. This study presents a ligand halogen engineering strategy for significantly enhancing the photoluminescence efficiency of 1D Cu–I coordination polymers by utilizing halogen-based chemical modifications. The chlorine-modified ligands increase structural rigidity, reducing electronic repulsion between copper and iodine atoms and minimizing photon loss through non-radiative recombination pathways, resulting in an impressive photoluminescence quantum yield of nearly 100%. The designed scintillators demonstrate improved radioluminescence intensity, low detection limits, and exceptional spatial resolution (16 lp/mm). This research offers an approach for creating highly emissive 1D Cu–I coordination polymers and highlights their potential in X-ray imaging applications in medical diagnosis and security checks.