Encapsulation of Screen-Printed Electrolyte-Based Organic Electronic Components for Long-Term Operation in Varying...

Area of Science:

• Materials Science
• Electrochemistry
• Device Engineering

Background:

• Printed electrochemical components, including organic electrochromic displays (OECDs) and organic electrochemical transistors (OECTs), are advancing but sensitive to environmental factors like humidity and temperature.
• The hygroscopic nature of device materials and electrochemical mechanisms necessitate protection against ambient conditions for reliable operation.

Purpose of the Study:

• To develop and evaluate an effective encapsulation strategy for printed electrochemical devices to mitigate environmental influences.
• To ensure the long-term stability and performance of screen-printed OECDs and OECTs under various harsh storage conditions.

Main Methods:

• Utilized commercially available printable adhesives and plastic substrates with pre-deposited barrier coatings for device encapsulation.
• Implemented a tight and conformal sealing process along the topography of printed conductors to block potential leakage paths.
• Tested encapsulated devices (OECDs and OECTs) after storage for 1 week under various conditions: 10% RH/10 °C, 80% RH/20 °C, and 90% RH/40 °C.

Main Results:

• Encapsulation successfully maintained device performance against environmental fluctuations.
• Screen-printed OECDs and OECTs retained their performance after storage in harsh conditions (low/low RH/T, high/high RH/T).
• Extended testing under extreme conditions (<3% RH/20 °C and 90% RH/40 °C) demonstrated excellent switching performance.
• Encapsulation significantly improved the color retention of OECDs in their colored state after storage.

Conclusions:

• The developed encapsulation method using printable barrier films provides effective protection for printed electrochemical devices.
• This approach ensures device reliability and enhances durability, enabling stable operation in diverse and challenging environments.
• The findings support the practical application of printed electrochemical devices by addressing their environmental sensitivity.