Positive temperature coefficient characteristics of poly(3-alkylthiophene)s

Poly(3-alkylthiophene)(P3AT) films were prepared by both electrochemical and chemically oxidative polymerization methods, and their positive temperature coefficient(PTC) characteristics were investigated in the range from 0 to 200°C. The change in the amount of tetrafluoroborate ion(BF4−) or iron(III) perchlorate(FeCl3) which were doped into P3AT film was also estimated by infrared(IR) and ultraviolet(UV) spectrophotometry. It was found that the P3AT films chemically polymerized at a low temperature had PTC characteristics, which was not affected by the dedoping involved in thermal treatment