Well‐Balanced Ambipolar Charge Transport of Diketopyrrolepyrrole‐Based Copolymers: Organic Field‐Effect Transistors and High‐Voltage Logic Applications

Abstract

A poly (3,6‐bis(thiophen‐2‐yl)−2,5‐bis(2‐decyltetradecyl)−2,5‐dihydropyrrolo[3,4‐c]pyrrole‐1,4‐dione‐co‐(2,3‐bis(phenyl)acrylonitrile)) (PDPADPP) copolymer, composed of diketopyrrolopyrrole (DPP) and a cyano (nitrile) group with a vinylene spacer linking two benzene rings, is synthesized via a palladium‐catalyzed Suzuki coupling reaction. The electrical performance of PDPADPP in organic field‐effect transistors (OFETs) and circuits is investigated. The OFETs based on PDPADPP exhibit typical ambipolar transport characteristics, with the as‐cast OFETs demonstrating low field‐effect hole and electron mobility values of 0.016 and 0.004 cm2 V−1 s−1, respectively. However, after thermal annealing at 240 °C, the OFETs exhibit improved transport characteristics with highly balanced ambipolar transport, showing average hole and electron mobility values of 0.065 and 0.116 cm2 V−1 s−1, respectively. To verify the application of the PDPADPP OFETs in high‐voltage logic circuits, compact modeling using the industry‐standard small‐signal Berkeley short‐channel IGFET model (BSIM) is performed, and the logic application characteristics are evaluated. The circuit simulation results demonstrate excellent logic application performance of the PDPADPP‐based ambipolar transistor and illustrate that the device annealed at 240 °C exhibits ideal circuit characteristics.