Highly stretchable polymer semiconductor thin films with multi-modal energy dissipation and high relative...

Area of Science:

• Materials Science
• Polymer Science
• Soft Electronics

Background:

• Stretchable polymer semiconductors (PSCs) are crucial for soft electronics, but achieving high charge carrier mobility alongside stretchability remains difficult.
• Existing PSCs often face challenges with irreversible morphology changes and performance degradation under strain.

Purpose of the Study:

• To investigate the relationship between energy dissipation mechanisms, relative stretchability (rS), and the performance of stretchable polymer semiconductor thin films.
• To identify a reliable parameter for assessing the reversibility and reliability of stretchable PSCs.

Main Methods:

• Fabrication of thin-film stretchable polymer semiconductors (<100-nm-thick).
• Characterization of energy dissipation mechanisms (entropic vs. enthalpic) under strain.
• Measurement of charge carrier mobility and morphological stability before, during, and after strain application.
• Definition and calculation of relative stretchability (rS).

Main Results:

• Stretchable PSCs with high rS exhibit multi-modal energy dissipation and maintain molecular ordering and electrical performance after strain release.
• A model polymer (P4) with the highest rS achieved an average charge carrier mobility of 0.2 cm2V-1s-1 under 100% biaxial strain.
• PSCs with low rS values showed irreversible morphological changes and significant degradation of electrical performance under strain.

Conclusions:

• Relative stretchability (rS) is a critical parameter for evaluating the reliability and reversibility of stretchable polymer semiconductor thin films.
• High rS is correlated with superior performance and recovery of electrical properties in stretchable PSCs.
• The findings provide a new metric for designing and selecting materials for advanced soft electronic applications.