Here we report a record thermoelectric power factor of up to 160 μ W m-1 K-2 for the conjugated polymer poly(3-hexylthiophene) (P3HT). This result is achieved through the combination of high-temperature rubbing of thin films together with the use of a large molybdenum dithiolene p-dopant with a high electron affinity. Comparison of the UV-vis-NIR spectra of the chemically doped samples to electrochemically oxidized material reveals an oxidation level of 10%, i.e. one polaron for every 10 repeat units. The high power factor arises due to an increase in the charge-carrier mobility and hence electrical conductivity along the rubbing direction. We conclude that P3HT, with its facile synthesis and outstanding processability, should not be ruled out as a potential thermoelectric material.
@article{arxiv.2103.03852,
title = {High thermoelectric power factor of poly(3-hexylthiophene) through in-plane alignment and doping with a molybdenum dithiolene complex},
author = {Viktoriia Untilova and Jonna Hynynen and Anna I. Hofmann and Dorothea Scheunemann and Yadong Zhang and Stephen Barlow and Martijn Kemerink and Seth R. Marder and Laure Biniek and Christian Müller and Martin Brinkmann},
journal= {arXiv preprint arXiv:2103.03852},
year = {2021}
}