High-mobility and low-voltage-operated organic field-effect transistors (OFETs) are demonstrated by the design of a new fluorinated benzothiadiazole-based conjugated polymer with fluorinated high-k polymer dielectrics. A record-breaking high hole mobility of 9.0 cm2 V−1 s−1 for benzothiadiazole-based semiconducting polymers is achieved by the excellent planarity of the semiconducting polymer.