Molecular Design of Stretchable Polymer Semiconductors: CurrentProgress and Future Directions

Stretchable polymer semiconductors have advanced rapidly in the past decade as materials required to realizeconformable and soft skin-like electronics become available. Through rational molecular-level design, stretchable polymersemiconductorfilms are now able to retain their electrical functionalities even when subjected to repeated mechanical deformations.Furthermore, their charge-carrier mobilities are on par with the bestflexible polymer semiconductors, with some even exceeding thatof amorphous silicon. The key advancements are molecular-design concepts that allow multiple strain energy-dissipationmechanisms, while maintaining efficient charge-transport pathways over multiple length scales. In this perspective article, we reviewrecent approaches to confer stretchability to polymer semiconductors while maintaining high charge carrier mobilities, with emphasison the control of both polymer-chain dynamics and thin-film morphology. Additionally, we present molecular design considerationstoward intrinsically elastic semiconductors that are needed for reliable device operation under reversible and repeated deformation.A general approach involving inducing polymer semiconductor nanoconfinement allows for incorporation of several other desiredfunctionalities, such as biodegradability, self-healing, and photopatternability, while enhancing the charge transport. Lastly, we pointout future directions, including advancing the fundamental understanding of morphology evolution and its correlation with thechange of charge transport under strain, and needs for strain-resilient polymer semiconductors with high mobility retention.

Automated summary

Stretchable polymer semiconductors have rapidly advanced in recent years, allowing them to retain their electrical functionalities under repeated mechanical deformations. They have achieved charge-carrier mobilities on par with flexible polymer semiconductors and even surpassed amorphous silicon. This is due to molecular design concepts that enable multiple strain energy-dissipation mechanisms while maintaining efficient charge-transport pathways.