Bright Cyan-Emissive Copper(I)-Halide Single Crystals for Multi-Functional Applications

Anti-counterfeiting has become a serious issue around the global world; fluorescence-based tags are praised for the low-cost and facile decryption process. However, the high-level anti-counterfeiting application requires incorporating multifunctional luminescent materials with response to different excitation sources. Herein, a dimeric Cu(I)-halide-clusters-assembled single-crystal (AEP)(2)Cu2I6 center dot 2I center dot 2H(2)O (AEP = N-aminoethylpiperazinium) concerning a high down-conversion photoluminescence quantum yield (PLQY) value of near unity is reported (lambda(ex) = 305 nm), which can also be activated by the near-infrared light and X-ray. The ultrafast spectroscopy and density functional theory calculations reveal that the broad-band emission originates from the recombination of self-trapped excitons. Remarkably, the high PLQY and excellent attenuation capability for X-ray confers an outstanding light yield of 55 650 photons MeV-1 to (AEP)(2)Cu2I6 center dot 2I center dot 2H(2)O, which is 5.25 times higher than the standard bismuth germaniumoxide scintillator. Such multi-light-stimulus response endows (AEP)(2)Cu2I6 center dot 2I center dot 2H(2)O with great application potential in anti-counterfeiting, solid-state lighting devices, and digital radiography.

Automated summary

This study reports a multifunctional luminescent material (AEP)(2)Cu2I6 center dot 2I center dot 2H(2)O, which exhibits high photoluminescence quantum yield and responds to multiple excitation sources. The material demonstrates a high light yield and excellent attenuation capability for X-ray, making it suitable for applications in anti-counterfeiting, solid-state lighting devices, and digital radiography.