A design strategy for high mobility stretchable polymer semiconductors

As a key component in stretchable electronics, semiconducting polymers have been widely studied. However, it remains challenging to achieve stretchable semiconducting polymers with high mobility and mechanical reversibility against repeated mechanical stress. Here, we report a simple and universal strategy to realize intrinsically stretchable semiconducting polymers with controlled multi-scale ordering to address this challenge. Specifically, incorporating two types of randomly distributed co-monomer units reduces overall crystallinity and longer-range orders while maintaining short-range ordered aggregates. The resulting polymers maintain high mobility while having much improved stretchability and mechanical reversibility compared with the regular polymer structure with only one type of co-monomer units. Interestingly, the crystalline microstructures are mostly retained even under strain, which may contribute to the improved robustness of our stretchable semiconductors. The proposed molecular design concept is observed to improve the mechanical properties of various p- and n-type conjugated polymers, thus showing the general applicability of our approach. Finally, fully stretchable transistors fabricated with our newly designed stretchable semiconductors exhibit the highest and most stable mobility retention capability under repeated strains of 1,000 cycles. Our general molecular engineering strategy offers a rapid way to develop high mobility stretchable semiconducting polymers. Designing intrinsically stretchable semiconducting polymers with suitable charge transport and mechanical properties required for stretchable electronic devices remains a challenge. Here, the authors report terpolymer-based semiconductors with intrinsically high stretchability and mobility.

Automated summary

This study presents a simple and universal strategy to achieve intrinsically stretchable semiconducting polymers with controlled multi-scale ordering, improving their stretchability and mechanical reversibility. By incorporating two types of co-monomer units, overall crystallinity and longer-range orders are reduced while maintaining high mobility, leading to improved mechanical properties. The proposed molecular design concept is observed to be applicable to various conjugated polymer systems, resulting in enhanced mechanical properties.