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Electrofluorochromic Device Based on a Redox-Active Europium(III) Complex
Yuna Kim1, Hitomi Ohmagari2, Akira Saso2
1Research Institute for Electronic Science, Hokkaido University, N-20, W-10, Kita-Ku, Sapporo 001-0020, Japan.
ACS Applied Materials & Interfaces
|September 15, 2020
Summary
This study demonstrates a simplified electrofluorochromic system using europium (Eu) helicate complexes. The reversible redox reactions of Eu ions enable efficient, switchable luminescence control in optoelectronic devices.
Area of Science:
- Materials Science
- Electrochemistry
- Luminescence
Background:
- Electrofluorochromism typically requires additional components for luminescence quenching.
- Controlling luminescence via redox reactions offers potential for advanced optoelectronic devices.
Purpose of the Study:
- To develop a simplified electrofluorochromic system using europium (Eu) helicate complexes.
- To investigate the reversible electrochemistry of Eu ions for luminescence switching.
Main Methods:
- Synthesis of helicate complexes (EuL) with a hexadentate pyridine derivative.
- Fabrication of a three-electrode electrochemical switching device using EuL in an ionic liquid ([BMIM][PF6]).
- Electrochemical cycling between Eu3+ and Eu2+ states to observe luminescence changes.
Main Results:
- A simplified electrofluorochromic system was achieved by utilizing the reversible redox chemistry of Eu ions.
- The EuL complexes exhibited enhanced red fluorescence in [BMIM][PF6] ionic liquid.
- Rapid luminescence quenching and restoration were observed upon electrochemical reduction (Eu2+) and oxidation (Eu3+), respectively.
- The device demonstrated reversible spectral fluctuations within ±2 V and excellent optoelectric properties.
Conclusions:
- The developed system offers an efficient and smart method for controlling Eu luminescence.
- This work paves the way for novel optoelectronic devices with tunable luminescence.
- The simplified approach overcomes limitations of traditional electrofluorochromic systems.
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