Conductive triethylene glycol monomethyl ether substituted polythiophenes with high stability in the doped state

ABSTRACT 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 4.2 × 10−4 cm2 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 1 month. 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). © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1079–1086 Polymers containing bithiophene with 3‐hexyl and methoxyethoxyethoxyethoxythiophene substituents were synthesized by McCullough method. The polymers showed lower band gaps as compared to poly(3‐hexylthiophene), thermal stability up to ~300 °C, and conductivities of ~700 S cm−1. Iodine doping caused transparency in thin films of the polymer, and the films were insoluble in common organic solvents. In thin‐film transistors, the polymers showed an average mobility of 4.2 × 10−4 cm2 V−1 s−1.