Facile synthesis and optoelectronic exploration of silylthiophene substituted benzodithiophene polymer for organic field effect transistors

This work reports the synthesis, characterization and organic field effect transistors (OFET) application of a novel conjugated polymer (PBDTDPP) based on silylthiophene substituted benzo[1,2-b:4,5-b′]dithiophene (BDT) donor and diketopyrrolopyrrole (DPP) acceptor obtained via Stille polymerization reaction. The polymer exhibits a broad absorption in the UV–visible spectrum ranging from 300 nm to 900 nm with the band edge of the polymer at 1.31 eV. Thermogravimetric analysis of the polymer demonstrates the stability up to 303 °C, and the cyclic voltammetry shows the HOMO and LUMO levels at −5.42 and −4.11 eV, respectively. Employing the polymer as an active layer in a bottom gate-top contact based OFET, hole mobility of as high as 9.34 × 10⁻² cm² V⁻¹ s⁻¹ with the On/Off ratio of ∼10⁴ was obtained. This work successfully demonstrates that the DPP and the silylthiophene substituted BDT are promising units to build D-A based copolymer for organic electronics.