Near-Infrared and Cyan Dual-Band Emission Copper Iodide Based Halides with [Cu6I9]3− Cluster

The luminescence property of various compounds is developed in the photoelectric applications field, while the near-infrared (NIR) dual-band emission of compounds is extremely challenging. Herein, 0D Cu(I)-based organic–inorganic module (ETA) 3 Cu 6 I 9 is synthesized to achieve NIR and cyan dual-band emission in metal halide systems. Density functional theory (DFT) calculations combined with comprehensive spectroscopic data reveal its emission mechanism. Under the excitation at 371 nm, (ETA) 3 Cu 6 I 9 shows the broadband NIR emission peaking at 775 nm with a large wavelength, attributed to the triple-cluster-center ( 3 CC) transition. Meanwhile, under 286 nm excitation, (ETA) 3 Cu 6 I 9 shows a bright cyan emission peaking at 490 nm, attributed to the metal-to-ligand charge transfer (MLCT) or halide-to-ligand charge transfer (XLCT) transitions. Moreover, (ETA) 3 Cu 6 I 9 presents relatively superior thermal and air stability. Benefiting from the good stability of (ETA) 3 Cu 6 I 9 , the as-fabricated NIR-LED device demonstrates great potential in biological imaging and night vision. This study opens up a new way for designing new non-toxic NIR and cyan dual-band emission materials, which guides to synthesize new materials in metal halide field.