High-mobility　organic　field-effect　transistors　(OFETs),　particularly　those　based　on　donor-acceptor　polymers,　often　exhibit　nonideal　transfer　characteristics,　limiting　their　practical　applications.　Doping　these　semiconductors　with　specifically　designed　organic　molecular　electron　acceptors　can　effectively　address　these　deficiencies.　By　employing　isoindigo-based　acceptors　with　appropriate　electron-withdrawing　groups　as　dopants　in　diketopyrrolopyrrole-thienothiophene-based　OFETs,　we　achieve　an　outstanding　transistor　performance　with　ideal　transfer　characteristics.　Comprehensive　analyses　using　ultraviolet-visible　absorption,　X-ray　diffraction,　ultraviolet　photoelectron　spectroscopy,　and　electrical　measurements　demonstrate　that　p-dopants　play　crucial　roles　in　enhancing　electron　transfer,　reducing　charge　carrier　traps,　and　lowering　contact　resistance,　thereby　eliminating　the　typical　＂double　slope＂　and　hysteresis　in　OFET　transfer　characteristics.