High-Performance n-Type Stretchable OFETs Enabled by Molecular Engineering of Flexible Polymers

Abstract

Stretchable organic field-effect transistors (OFETs) have emerged as promising semiconductor devices for flexible electronics, combining mechanical deformability with stable electrical performance. However, developing high-performance n-type stretchable semiconductors remains challenging. In this study, we designed three novel n-type polymers (P1-P3) by incorporating flexible chains into an azo-benzodifurandione-based oligo(p-phenylene vinylene) (azo-BDOPV) backbone, achieving balanced mechanical and electrical properties. Using polydimethylsiloxane substrates, gold and silver nanowires electrodes, and polyvinyl alcohol (PVA) dielectric layers, we fabricated fully stretchable top-gate n-type OFETs. The devices demonstrated excellent initial electron mobilities of 0.44, 0.34, and 0.52 cm2V-1s-1 for P1-P3 respectively, with P3 showing superior performance. Remarkably, P3 maintained mobilities of 0.48-0.29 cm2V-1s-1 (strain parallel to the charge transport direction) and 0.42-0.26 cm2V-1s-1 (strain perpendicular to the charge transport direction) under 15-50% deformation, demonstrating exceptional mechanical-electrical stability. All three polymer films show uniform surface morphology and molecular stacking, with polymer P3 having the most ordered edge-on stacking, which is consistent with its excellent device performance. These results highlight the effectiveness of molecular engineering in developing stretchable n-type semiconductors with mechanical flexibility and efficient charge transport, providing valuable insights for the design and application of high-performance fully stretchable OFETs, advancing the development of next-generation flexible and wearable electronics.