Ambipolar charge transport of diketopyrrolepyrrole-silole-based copolymers and effect of side chain engineering: Compact model parameter extraction strategy for high-voltage logic applications

The copolymers P24DPP-silole and P29DPP-silole, each composed of diketopyrrolopyrrole (DPP) and silole derivatives, were synthesized using a Stille coupling reaction, and their electrical performances in organic field-effect transistors (OFETs) and circuits were investigated. While both the as-spun OFETs exhibited quite low field-effect hole mobility values, the OFETs subjected to thermal annealing at 150 °C exhibited typical ambipolar transport characteristics with average hole and electron mobility values of 1 × 10⁻¹ cm²/(V s) and 2 × 10⁻³ cm²/(V s). Because the compact model was necessary to perform circuit design with the synthesized OFETs, a strategy for extracting compact model parameters was proposed for high-voltage logic circuit applications by using the industry standard compact Berkeley short-channel IGFET model (BSIM).