Synthesis and Characterization of a Pyromellitic Diimide-Based Polymer with C- and N-Main Chain Links: Matrix for Solution-Processable n-Channel Field-Effect Transistors

A highly soluble pyromellitic diimide-based polymer was obtained through imidization polymerization. The novel architecture features diimide subunits linked alternately at 3,6 and N,N′ positions. The polymer is highly transparent in the near-ultraviolet–visible regions. Smooth and uniform thin-films were obtained through spin-coating even after blending the polymer with PCBM in 1:9 polymer/PCBM weight ratio. While the polymer itself has modest electron mobility in typical bottom-gate top-contact OFETs, an electron mobility of 3 × 10–3 cm2 V–1 s–1 was achieved for the blend, which increased to 10–2 cm2 V–1 s–1 on exposure to propylamine. Thus, polyimides are demonstrated as promising binder materials for solution-processable n-channel semiconductor blends, of which very few examples are known.