Voltage-Tunable Multicolor, Sub-1.5 V, Flexible Electrochromic Devices Based on Ion Gels

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Flexible electrochromic devices (ECDs) are crucial for advanced display technologies.
• Ion gels offer unique properties as electrolytes for flexible electronic applications.

Purpose of the Study:

• To fabricate voltage-tunable multicolor electrochromic devices (ECDs) using flexible ion gels.
• To investigate the electrochromic behavior of different viologen derivatives within these devices.
• To assess the performance metrics including coloration efficiency and power consumption.

Main Methods:

• Fabrication of flexible ion gels incorporating copolymers and ionic liquids.
• Incorporation of dimethyl ferrocene (dmFc) as an anodic species.
• Employment of monoheptyl viologen (MHV+) and diheptyl viologen (DHV2+) as electrochromic materials.
• Characterization of electrochromic properties, coloration efficiency, and power consumption.

Main Results:

• Developed flexible ECDs exhibiting voltage-tunable multicolor capabilities (magenta and blue).
• Achieved high coloration efficiencies of 87.5 cm²/C (magenta) and 91.3 cm²/C (blue).
• Demonstrated ultralow power consumption for maintaining colored states (∼248 μW/cm² for magenta, ∼72 μW/cm² for blue).
• Highlighted distinct electrochromic behavior and voltage ranges for MHV+ and DHV2+.

Conclusions:

• Flexible ion gel-based ECDs with voltage-tunable multicolor properties are successfully fabricated.
• The distinct electrochemical behavior of viologen derivatives enables multicolor switching.
• These devices represent attractive candidates for functional electrochemical displays due to their performance and flexibility.