A Rare Blue‐Light‐Excitable—Near‐Infrared‐Emissive Copper(I) Iodide Hybrid with Facile Synthesis for Near‐Infrared Imaging

ABSTRACT Metal halide hybrid luminescent materials have attracted significant attention due to their tunable emission properties and excellent photoelectric performance. However, achieving metal halides that exhibit near‐infrared (NIR) emission under blue light excitation remains a major challenge. This paper reports a novel 2D copper(I) iodide hybrid material, Cu 2 I 2 (THQx) (THQx = 5,6,7,8‐Tetrahydroquinoxaline), which is constructed by linking ‐Cu 2 I 2 ‐ chains with the THQx ligand and achieves broadband NIR luminescence. It can be effectively excited by blue LEDs and has a peak emission at 730 nm with a full width at half maximum of 159 nm. Theoretical calculations indicate that its luminescence originates from the triplet metal/halide‐to‐ligand charge transfer ( 3 MLCT/HLCT). This material also exhibits excellent thermal stability, air stability, and photostability, demonstrating potential applications in night vision and biological imaging in NIR phosphor‐converted LED (pc‐LED) devices. This research not only expands the application boundaries of copper(I) halide hybrid materials, but also provides a new approach for the development of low‐cost and environmentally friendly NIR luminescent materials.