Regular H-Bonding-Containing Polymers with Stretchability up to 100% External Strain for Self-Healable Plastic Transistors

Abstract

Intrinsically stretchable, electroactive materials featuring self-healing abilities will allow for a variety of nextgeneration stretchable electronics. Here, we synthesize diketopyrrolopyrrole-based "alternating" copolymers with urethane-containing side chains, that is, PDPP urethane copolymers, and use them as active layers in intrinsically stretchable and self-healable plastic transistors. The long-branched urethane side chains possessing moderate H-bonding strength enable sufficient solubility and excellent dynamic bonding, facilitating the stress dissipation under mechanical deformation. PDPP urethane thin films exhibit outstanding stretchability up to 100% external strain without degradation of electrical performance in the organic transistor platform. They also feature self-healing properties with the healing of cracks and the recovery of electrical properties after treatment. The structure−property relationships of PDPP urethane thin films under strain have been thoroughly investigated using a variety of characterization methods. Our results demonstrate a viable approach for the development of stretchable and self-healable plastic electronics using stretchable, semiconducting copolymers obtained via side chain engineering.

Optimizing the self‐assembly of conjugated polymers and small molecules through structurally programmed non‐covalent control

“…However, designer side‐chains possessing hydrogen bonding functional groups, such as amides and ureas, can accomplish more than simply imparting solubility. Hydrogen bonding side‐chains can improve interchain packing, solid‐state microstructure, and charge transport of both n‐type and p‐type conjugated polymers, 109–111 with amide groups especially useful given the strength of hydrogen bonding between them 112–115 . An exemplar of this design came in 2018 from Ocheje et al 116 Their family of diketopyrrolopyrrole polymers (Figure 7) possessed amide‐containing aliphatic chains that participated in interchain hydrogen bonding throughout the polymer network.…”

Pushing the Limits of Flexibility and Stretchability of Solar Cells: A Review

“…Block copolymerization has been proposed as a promising route to engineer the mechanical and electronic properties of conjugated polymers. [ 123,259–262 ] Lipomi et al, studied the impact of alkyl side chains on the electronic and mechanical properties of conjugated polymers synthesized via copolymerization of different monomers. [ 121 ] Systematic comparisons of P3HpT, a P3HT:P3OT blend, a block copolymer (P3HT‐b‐P3OT) and a random copolymer (P3HT‐co‐P3OT) were reported ( Figure A).…”

Incorporation of hydrogen‐bonding units into polymeric semiconductors toward boosting charge mobility, intrinsic stretchability, and self‐healing ability

“…Moreover, the device performance showed no noticeable decrease on human skin after folding, twisting and stretching with the movement of human body. This strategy was also successfully applied to other semiconducting polymers to enhance the flexibility and stretchability of the semiconducting thin films 39,41,78,79 …”

“…As for side chain engineering, the structures of side alkyl chains with regard to the branching site and the lengths of side chains have been usually finely tailored 9,34–37 . Meanwhile, incorporation of H‐bonding units into conjugated polymers is an effective means to regulate the crystalline behaviors and mechanical properties 38–47 …”