All‐Solution Processed OFETs from Non‐Chlorinated Solvents Based on New Isoindigo‐Based Conjugated Polymer

Here, an Isoindigo (IID) comprised with Naphthodithiophene (NDT)‐based low band‐gap donor–acceptor copolymer semiconductor is designed, synthesized, and investigated. The newly reported polymer provides good solubility in a range of halogenated and non‐halogenated solvents due to the attachment of long branched alkyl chains on the Isoindigo core. After optimizing the performance of organic field effect transistors (OFETs) through the use of high‐boiling‐point chlorinated solvents, A similar approach is followed to realize transistors without the need of using halogenated solvents as a green approach. Well‐working transistors are shown with mobility values in a similar range as obtained for OFETs with films prepared from halogenated solvents, while significantly reducing the environmental impact. Finally, all‐solution‐processed, flexible OFETs are prepared without the use of halogenated solvents, which is an important step in the view of potential large area production of flexible electronics.