Achieving Dual-Color Luminescence via Halogen Regulation in Copper-Based Halides for Anticounterfeiting.

Area of Science:

• Materials Science
• Inorganic Chemistry
• Luminescence

Background:

• Multicolor luminescent materials are crucial for anticounterfeiting and information security.
• Copper-based halides are explored for their unique optical properties.

Purpose of the Study:

• To synthesize novel zero-dimensional copper-based halides with tunable dual-color emission.
• To investigate the structure-property relationships governing their luminescence.
• To explore applications in anticounterfeiting and information security.

Main Methods:

• Synthesis of two novel zero-dimensional copper-based halides: (C5H11N3)2Cu3Cl7·H2O and (C5H11N3)2Cu2Br6.
• Characterization of crystal structures and optical properties (emission spectra, Stokes shifts, lifetimes, photoluminescence quantum yield (PLQY)).
• Density functional theory (DFT) calculations to understand structure-property correlations.

Main Results:

• Successful synthesis of dual-color emitting copper halides via halogen regulation.
• Observation of yellow (549 nm) and blue (457 nm) emission attributed to self-trapped exciton (STE) emission.
• Achieved large Stokes shifts and long luminescence lifetimes; higher PLQY (23.79%) for the bromide compared to the chloride (15.90%).
• DFT calculations confirmed the significant role of copper halide clusters in optical performance.

Conclusions:

• The synthesized copper-based halides demonstrate tunable multicolor luminescence through halogen regulation.
• The materials exhibit promising characteristics for anticounterfeiting and information security applications.
• This work provides insights into designing advanced luminescent materials based on copper halides.