Aggregation structure and glass transition of intrinsically stretchable semiconducting polymers

Stretchable semiconducting polymers are indispensable elements for next-generation electronics. However, the influence of molecular chain dynamics on the performance of stretchable devices remains unclear, which hinders molecular design efforts toward wanted properties. Herein, the relationship between polymer chain kinetics and stretchable properties are investigated in intrinsically stretchable device systems. By intuitively validating the strain-induced chain alignment and transition trend of aggregation structure, the determinants of stretchability and stretch-state charge transport mechanism are elucidated, interpreting preserved electrical performance even after large cracks formed. Specifically, the main- and side-chain glass transitions can be associated with the variation of the packing structure and can further render significant performance variations across the glass transition temperature. The side-chain dynamics predominantly impact stretchability, while the effectively aggregated backbones primarily maintain charge transport paths. The findings inform future optimization of molecular design in intrinsically stretchable systems.