Synthesis of two conducting polymers containing 3-hexylthiophene and 3-[2-(2-(2-methoxyethoxy)ethoxy)ethoxy]thiophene is demonstrated. In thin-film transistors, the high-molecular-weight polymer shows an average mobility of 4.2x 10(-4) cm(2) V-1 s(-1). Most importantly, the polymers have high conductivity upon doping with iodine and also have high stability in the doped state with high conductivities measured even after 1month. Furthermore, the doping causes transparency to thin films of the polymer and the films are resistant to common organic solvents. All these properties indicate a great potential for the iodine-doped polymer to be used as an alternative to commercially available poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate). (c) 2019 Wiley Periodicals, Inc.