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Quadruple Anticounterfeiting Encryption: Anion-Modulated Forward and Reverse Excitation-Dependent Multicolor
Guowei Xiao1, Yu-Juan Ma1, Xiaoyu Fang1
1Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Key Laboratory of Radiopharmaceuticals Ministry of Education, Beijing Normal University, Beijing 100875, China.
ACS Applied Materials & Interfaces
|June 22, 2022
Summary
Researchers developed new ionic crystalline materials from cytosine and anions, achieving tunable afterglow for applications like anticounterfeiting and data storage. These materials exhibit unique light emission properties based on molecular interactions and excitation conditions.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Photophysics
Background:
- Molecule-based afterglow materials with long-lived excited states are crucial for advanced applications.
- Controlling luminescence properties in solid-state materials remains a significant challenge.
Purpose of the Study:
- To fabricate novel two-component ionic crystalline materials for tunable afterglow emission.
- To investigate the relationship between molecular interactions, crystal structure, and luminescence properties.
- To explore applications in information encryption.
Main Methods:
- Self-assembly of cytosine with various anions (phosphate, halogens) under ambient conditions.
- Characterization of crystal structures and intermolecular interactions.
- Spectroscopic analysis to study photoluminescence, including room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF).
- Evaluation of excitation wavelength, time evolution, and temperature-dependent emission.
Main Results:
- Successfully synthesized new cytosine-anion ionic crystals with tunable optical properties.
- Observed H-aggregation-induced green to yellow RTP and ESIPT-dominated cyan RTP to deep blue TADF emission.
- Demonstrated control over luminescence color by adjusting excitation and environmental conditions.
- Utilized the multicolored emission for quadruple information encryption.
Conclusions:
- Anion modulation is an effective strategy for achieving color-tunable afterglow in ionic crystals.
- The developed materials exhibit both static and dynamic luminescence control.
- These findings provide insights for designing excitation-dependent luminescent materials for various applications.
