Impact of Oligoether Side-Chain Length on the Thermoelectric Properties of a Polar Polythiophene
Review article, 2024
Conjugated polymers with oligoether side chains make up a promising class of thermoelectric materials. In this work, the impact of the side-chain length on the thermoelectric and mechanical properties of polythiophenes is investigated. Polymers with tri-, tetra-, or hexaethylene glycol side chains are compared, and the shortest length is found to result in thin films with the highest degree of order upon doping with the p-dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F(4)TCNQ). As a result, a stiff material with an electrical conductivity of up to 830 +/- 15 S cm(-1) is obtained, resulting in a thermoelectric power factor of about 21 mu W m(-1) K-2 in the case of as-cast films. Aging at ambient conditions results in an initial decrease in thermoelectric properties but then yields a highly stable performance for at least 3 months, with values of about 200 S cm(-1) and 5 mu W m(-1) K-2. Evidently, identification of the optimal side-chain length is an important criterion for the design of conjugated polymers for organic thermoelectrics.
conjugated polymer
chemical doping
organicthermoelectrics
side-chain length
electrical conductivity
Author
Mariavittoria Craighero
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Jiali Guo
Spanish National Research Council (CSIC)
Sepideh Zokaei
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Sophie Griggs
University of Oxford
Junfu Tian
University of Oxford
Jesika Asatryan
University of A Coruña
Joost Kimpel
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Renee Kroon
Linköping University
Kai Xu
Spanish National Research Council (CSIC)
Juan Sebastian Reparaz
Spanish National Research Council (CSIC)
Jaime Martin
POLYMAT
University of A Coruña
Iain Mcculloch
University of Oxford
Mariano Campoy-Quiles
Spanish National Research Council (CSIC)
Christian Müller
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
ACS Applied Electronic Materials
26376113 (eISSN)
Vol. 6 5 2909-2916Hybrid and Organic Thermoelectric Systems (HORATES)
European Commission (EC) (EC/H2020/955837), 2021-03-01 -- 2025-02-28.
Subject Categories
Polymer Chemistry
Inorganic Chemistry
Other Materials Engineering
DOI
10.1021/acsaelm.3c00936