Undoped Monophase Hybrid Copper(I) Halides with Highly Efficient Excitation‐Dependent Dual‐Color Emission for Multiple Applications

Abstract Low‐dimensional hybridized Cu(I)‐based halide materials represent a new class of materials with excellent photoluminescent properties, garnering significant interest as promising candidates for scintillation applications. In this work, a novel metal halide with the structure (PZ) 2 Cu 2 I 6 •H 2 O (PZ represents piperazine) is reported, which exhibits efficient cyan and orange photoluminescence at room temperature under UV lamps at 254 and 356 nm, respectively, with photoluminescence quantum yields of up to 82.9% and 40.5%. The energy transfer processes are investigated through temperature‐dependent photoluminescence measurements. (PZ) 2 Cu 2 I 6 •H 2 O demonstrates strong X‐ray absorption and a notable light yield of up to 26 700 photons MeV −1 . A novel method has prepared a flexible scintillation film with an ultra‐high spatial resolution of 16 lp mm −1 . It has an ultra‐thin thickness averaging only 38 µm and has a ductility of over 275%. Which can be used for X‐ray imaging. Furthermore, owing to its wavelength‐dependent multicolor emission under ultraviolet excitation, it is also suitable for preparing luminescent inks for encrypted anti‐counterfeiting applications.