Enhancing the healing ability and charge transport thermal stability of a diketopyrrolopyrrole based conjugated polymer by incorporating coumarin groups in the side chains

Abstract In this paper, we present a new design strategy for healable polymeric semiconductors, which are demanding for the future flexible electronics, by incorporating coumarin groups in the polymer side chains. The selection of coumarin groups is based on the fact that photo‐dimerization can occur to coumarins upon UV light irradiation, thus side chains of conjugated polymers with coumarins can be cross‐linked. The photo‐crosslinking of side chains has negligible effect on the thin film morphology and interchain packing order for the DPP‐based conjugated polymer PDPP4T‐DCM with coumarins in the side chains. However, the photo‐crosslinking can facilitate the repair of the mechanically damaged thin film of PDPP4T‐DCM and the recovery of the semiconducting properties. Additionally, the photo‐crosslinking due to the coumarins in the side chains can lock thin film morphology and thus improve the thermal stability of charge transport.