Well-balanced ambipolar diketopyrrolopyrrole-based copolymers for OFETs, inverters and frequency doublers

Conjugated polymers with well-balanced ambipolar charge transport is essential for organic circuits at low cost and large area with simplified fabrication techniques. Aiming at this point, herein, a novel asymmetric thiophene/pyridine-flanked diketopyrrolopyrrole-based copolymer (PPyTDPP–2FBT) is designed and synthesized. Due to the effect of incorporating F atoms on molecular energy alignment and conjugation conformation, the PPyTDPP–2FBT copolymer exhibits typical V-shaped ambipolar field-effect transfer characteristics with well-balanced hole and electron mobilities of 0.64 and 0.46 cm2 V−1 s−1, respectively. Furthermore, organic digital and analog circuits such as inverters and frequency doublers are successfully constructed based on solution-processed films of the PPyTDPP–2FBT copolymers which show a typical circuit operating mode with a high gain of 133 due to the well-balanced electrical properties. In addition, PPyTDPP–2FBT-based devices also demonstrate good stability and batch repeatability, suggesting their great potential applications in organic integrated electronic circuits.