Ionogel/Copper Grid Composites for High-Performance, Ultra-Stable Flexible Transparent Electrodes

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Flexible transparent electrodes (FTEs) are crucial for advanced optoelectronics.
• Developing stable, low-cost copper (Cu)-based FTEs remains a significant challenge.
• Existing alternatives like indium tin oxide (ITO) have limitations in flexibility and cost.

Purpose of the Study:

• To create a facile method for fabricating high-performance, ultra-stable Cu-based FTEs.
• To enhance the mechanical flexibility and stability of Cu grid FTEs.
• To offer a viable alternative to ITO for flexible optoelectronic applications.

Main Methods:

• Fabrication of Cu grid (CuG) FTEs on polyethylene terephthalate (PET) via UV lithography-assisted electroless deposition.
• Encapsulation of CuG@PET with a thin poly(1-vinyl-3-ethylimidazolium bis(trifluoromethanesulfonyl)imide) (P[VEIM][NTf2]) ionogel layer.
• Characterization of the electrical and optical properties of the composite FTEs.

Main Results:

• The developed composite FTE (ionogel/CuG@PET) achieved a sheet resistance of 10.9 Ω sq⁻¹.
• An optical transmittance of 90% at 550 nm was recorded.
• The ionogel layer significantly improved mechanical flexibility and stability due to superwettability.

Conclusions:

• A novel, high-performance, and stable Cu-based FTE was successfully fabricated.
• The ionogel encapsulation provides excellent mechanical robustness and stability.
• This Cu-based FTE presents a promising alternative to ITO for practical optoelectrical devices.