A Design Strategy for Intrinsically Stretchable High-Performance Polymer Semiconductors: Incorporating Conjugated Rigid Fused-Rings with Bulky Side Groups

Abstract

Strategies to improve stretchability of polymer semiconductors, such as introducing flexible conjugation-breakers or adding flexible blocks, usually result in degraded electrical properties. In this work, we propose a concept to address this limitation, by introducing conjugated rigid fused-rings with optimized bulky side groups and maintaining a conjugated polymer backbone. Specifically, we investigated two classes of rigid fusedring systems, namely, benzene-substituted dibenzothiopheno[6,5b:6′,5′-f ]thieno[3,2-b]thiophene (Ph-DBTTT) and indacenodithiophene (IDT) systems, and identified molecules displaying optimized electrical and mechanical properties. In the IDT system, the polymer PIDT-3T-OC12-10% showed promising electrical and mechanical properties. In fully stretchable transistors, the polymer PIDT-3T-OC12-10% showed a mobility of 0.27 cm 2 V −1 s −1 at 75% strain and maintained its mobility after being subjected to hundreds of stretching−releasing cycles at 25% strain. Our results underscore the intimate correlation between chemical structures, mechanical properties, and charge carrier mobility for polymer semiconductors. Our described molecular design approach will help to expedite the next generation of intrinsically stretchable high-performance polymer semiconductors.

From stretchable and healable to self-healing semiconducting polymers: design and their TFT devices

“…Please do not adjust margins (d) The effect of conjugated rigid fused-rings with optimized bulky side groups in the conjugated polymer backbone. 95 Copyright: 2021, American Chemical Society. Please do not adjust margins The average field-effect mobility stretched in parallel and perpendicular directions and the mechanical-mobility resistance of the of the PII2T-C6 and PII2T-C8 thin films under repeated 400 stretching/releasing cycles with a maximum strain of 60% in a controlled parallel to the strain direction of the strain.…”

“…The rigid fused-ring systems investigated by the researchers, namely, benzenesubstituted dibenzothiopheno[6,5-b:6ʹ,5ʹ-f]thieno [3,2-b]thiophene (Ph-DBTTT) and indacenodithiophene (IDT) systems. 95 In fully stretchable transistors as shown in Fig. 4d, the polymer PIDT-3T-OC12-10% showed a mobility of 0.27 cm 2 V -1 s -1 at 75% strain and maintained its mobility after being subjected to hundreds of stretching-releasing cycles at 25% strain.…”

Recent Structural Engineering of Polymer Semiconductors Incorporating Hydrogen Bonds

“…Moreover, the formed noncovalent interchain crosslinking network can offset the damage caused by external stress to a certain extent and provide the superiority of mechanical flexibility. [41][42][43][44] There are many types of noncovalent interactions such as halogen bond (Cl•••Cl, Br•••Br, etc. ), chalcogen bond (S•••F, S•••O, etc.…”

Strain-insensitive naphthalene-diimide-based conjugated polymers through sequential regularity control

“…21 The feasible approaches to structural engineering can be divided into three categories: (1) random copolymerization with dimensionally similar monomers, 22,23 (2) adoption of rigid fused-ring backbones for a near-amorphous structure, 24,25 and (3) introduction of conjugated side groups on the side chains to promote chain aggregation 26,27 or the combination of a fused-ring backbone and conjugated side groups. 28 Most of the methods capable of improving mobility-stretchability properties are applicable mainly to p-type CPs and are seldom reported in n-type CPs owing to the instability of carrier transport and limited types of backbones. Next, the mobility-stretchability properties of the prototype p-type CP poly(3-hexylthiophene) (P3HT) have been diversely modified by using molecular weight control, 29 random copolymerization 30 and regioregularity control 31,32 and by forming block copolymers with an insulating segment.…”