Title
Improved room-temperature thermoelectric characteristics in F4TCNQ-doped CNT yarn/P3HT composite by controlled doping
Author
May Thu Zar Myint Takeshi Nishikawa, Hirotaka Inoue, Kazuki Omoto, Aung Ko Ko Kyaw, Yasuhiko Hayashi
Year
2021
Journal
Organic Electronics
Abstract
High room-temperature thermoelectric performance is important for low-grade waste heat power generation as there are plenty of heat thrown away uselessly in our daily life, most of which are below 100 °C. However, most of the thermoelectric materials are limited to high temperature application. In this work, room-temperature thermoelectric power factor of carbon nanotube (CNT) yarn is improved by controlled doping, which is achieved by making composite with poly 3-hexylthiophene −2, 5-diyl (P3HT) followed by doping with 2, 3, 5, 6-tetrafluo-7, 7, 8, 8-tetracyanoquinodimethane (F4TCNQ). The temperature-dependent Seebeck coefficient based on power–law model suggests that P3HT shifts the Fermi energy of CNT yarn towards the valence band edge, and reduces the ionic scattering and carrier relaxation time. As a result, the Seebeck coefficient is increased while the variation of Seebeck coefficient with temperature is reduced, and hence, the room-temperature thermoelectric power factor is improved. With controlled doping, the power factor of CNT yarn/P3HT composite reaches to 1640–2160 μW m−1K−2 at the temperature range of 25–100 °C, which is higher than that of CNT yarn alone.
Instrument
NRS-4500
Keywords
Room-temperature thermoelectric, P3HTCNT yarn, F4TCNQ doped, Conducting polymer composite, Raman spectroscopy