Hyperbranched Diketopyrrolopyrrole-based Polymers Constructed via Linear Side-Chains towards Organic Field-Effect Transistors.

Conjugated polymers with high charge mobilities have drawn increasing attention in organic field-effect transistors (OFETs) in recent years. However, OFETs of conjugated polymers with high mobility and good device stability remain a challenge. In this article, we report a hyperbranched polymer approach to improve the charge mobility and device stability. Three hyperbranched diketopyrrolopyrrole-based polymers were designed and synthesized via linear alkyl side-chain linkers. The results show that 2D topological hyperbranched polymers form stable thin film microstructures, and thus improve the device stability, since the conjugated moiety is interconnected by linear alkyl chain. Besides, the incorporation of linear alkyl chain instead of branching alkyl one reduce steric hindrance, and improve the microstructure ordering as well as the charge mobility. Bar-coated OFETs result demonstrates that the devices mobilities and operational stabilities (bias stability and bending resistance) are both improved. All these indicate that hyperbranched polymer is a potential candidate for future application.