Effect of film thickness and crystallinity on the thermoelectric properties of doped P3HT films

The influence of film thickness and crystallinity of poly(3-hexylthiophene) (P3HT) on the thermoelectric properties of doped P3HT films was systematically investigated. To obtain excellent thermoelectric properties, highly crystalline P3HT films were prepared by simple wire-bar-coating. The P3HT films doped with a ferric chloride exhibited power factors of up to 35.0 μW m−1 K−2 at room temperature. This study suggests that it could be possible to optimize the thermoelectric properties of the conjugated polymer films by controlling the film thickness and polymer structure. Further, the processing method and conjugated polymers selected for thermoelectric applications should be considered carefully because they determine the final characteristics of the films produced.