Enhancing the Mechanical Durability of an Organic Field Effect Transistor through a Fluoroelastomer Substrate with a Crosslinking‐Induced Self‐Wrinkled Structure

Abstract

In this study, a facile method to enhance the ductility of conjugated polymer thin films by using elastomeric substrates with a self‐wrinkled structure is demonstrated. A brittle polymer of poly(selenophene‐alt‐3,6‐dithophene‐2‐yl‐2,5‐bis‐(2‐octyldodecyl)‐2,5‐dihydro‐pyrrolo[3,4‐c]pyrrole‐1,4‐dione) (PSeDPP) is transferred onto a poly(vinylidene fluoride‐hexafluoropropylene) (PVDF‐HFP) substrate, which has a wrinkled structure formed during thermal curing. The ductility of the PSeDPP thin film on the fluoroelastomer substrate is significantly improved compared to that on poly(dimethyl siloxane) (PDMS). When the fluoroelastomer is employed in a fully stretchable transistor as the substrate as well as the dielectric layer, the device exhibits ideal transfer characteristics and excellent mechanical robustness. The transistor device with high electrical performance (≈1.51 (cm2 V−1 s−1) mobility, 104 on–off current ratio) can be stretched up to 30% over 2000 cycles and maintain device performance with 7.32 × 10−1 (cm2 V−1 s−1) and ≈104 on–off current ratio. To demonstrate the compatibility of this method with other semiconducting materials, conjugated polymers such as poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) and poly(isoindigo‐bithiophene) (PII2T‐C8C10) are also used as the active layer, and they show similar results to the PSeDPP. Hence, this method demonstrates a general strategy to significantly enhance the ductility of the conjugated polymer thin films, achieving stretchable organic field effect transistors with both high performance and mechanical compliance.