Thionated stereoisomer enhance the mixed conduction, ambient stability and mechanical deformability for high-performance small molecular n-type organic electrochemical transistors

Abstract

High performance stretchable organic mixed ionic-electronic conductors with highly stability are extremely demanding for flexible bioelectronics. However, very little is known about the correlation between the mixed conduction and both stability and mechanical deformability of n-type small molecular organic electrochemical transistors (OECTs). Herein, a stereoisomerism was reported as an effective platform to address these challenges by introducing a concept of coupling rigid tetrachloro perylene diimides (PDI) skeleton and amorphous thionation stereoisomer to afford the stereoisomerism of dithionated oligo(ethylene glycol) functionalized PDI (2S-gPDI). In further, for the first time we carried out proof-of-concept experiments to build the correlations between both chemical/microstructures and the thin/thick films’ ambient stability as well as mechanical deformability based on this novel small-molecule mixed conductors. Our results reveal that the thionation stereoisomerism render 2S-gPDI higher figure of merit μC* and ambient stability as well as higher mechanical deformability owing to the lower LUMO levels, porous film morphology and lower degree of film crystallinity, when compared with the parent unthionated gPDI-based mixed conductors. It is envisioned that the coupling rigid skeleton and amorphous stereoisomer concept will guide the next generation of high stable small-molecules stretchable OECTs.