Material design strategies for flexible n-type polymer semiconductors

Abstract

Flexible n-type polymer semiconductors enable materials for soft, wearable, and biointerfacing electronics, yet their development still lags behind p-type counterparts in both structural diversity and device performance. A unifying design goal is to preserve locally ordered aggregates and continuous percolated charge-transport pathways. In this perspective, we discuss recent advances from the view of multilevel design of conjugated polymers, covering molecular-level backbone and side-chain engineering, microstructure control through molecular-weight optimization, chain orientation modulation, and blending or networking with a soft matrix. Finally, we outline key remaining challenges and future opportunities for flexible n-type polymer semiconductors, including expanding the polymer scope, transitioning from empirical optimization toward predictive design models, building in situ characterization under mechanical deformation, and establishing standardized and application-relevant benchmarking protocols and open access databases, and improving long-term stability as well as manufacturing scalability.