Melt-Processable and Thermally Driven Self-Healing Luminescent Cu(I) Hybrid Metal Halides

Despite the fascinating optical and electronic properties of emerging Cu(I) halides, their high melting points, irreversible decomposition, and intrinsic instability have hindered optoelectronic applications. Here, we designed novel Cu(I) halides, namely C 12 H 28 NCuCl 2 and C 20 H 48 N 2 Cu 4 Cl 6, with significantly lower melting points (86 and 122 °C), enabling remarkable moldability. Intriguingly, this investigation demonstrates that the aging and luminescence-quenching phenomena observed in C 12 H 28 NCuCl 2 and C 20 H 48 N 2 Cu 4 Cl 6 crystals resulting from the air oxidation can be effectively reversed through controlled heat treatment. The resulting C 12 H 28 NCuCl 2 and C 20 H 48 N 2 Cu 4 Cl 6 crystals exhibit broadband emission with photoluminescence quantum yields of 74.78% and 46.52%, respectively. Furthermore, C 12 H 28 NCuCl 2 displays bright radioluminescence, showing an internal X-ray to light conversion efficiency of 36 506 photons/MeV under steady state X-ray illumination. The inherent melt processability of these materials empowers their transformation into diverse shapes suitable for practical applications. Herein, a sizable C 12 H 28 NCuCl 2 scintillator screen (∼10 cm × 7 cm) was successfully prepared through a melt-processing method, achieving X-ray imaging resolution of 9 line pairs per millimeter (9 lp/mm). This study demonstrates the potential of melt-processable Cu(I) halides to be applied in various applications, because of their unique properties, including facile processing, moldability, and high X-ray luminescence.