Premium
Structural modulation induced by cobalt‐based ionic liquids for enhanced thermoelectric transport in PEDOT:PSS
Author(s) -
Lu Yannan,
Wu Aoyun,
Sha Chenwei,
Hang Xiaochun,
Young David James
Publication year - 2021
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.202100720
Subject(s) - seebeck coefficient , thermoelectric effect , pedot:pss , ionic liquid , materials science , cobalt , ionic bonding , delocalized electron , ion , chemical physics , chemical engineering , chemistry , polymer , thermodynamics , organic chemistry , composite material , catalysis , physics , engineering , metallurgy
Abstract Poly(3,4ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS) has been intensively studied for its thermoelectric applications. Structural modulation to improve crystalline ordering, chain conformation and film morphology is a promising way to decouple the trade‐off between conductivity and Seebeck coefficient and thus improve the thermoelectric power factor. Post treatment with ionic liquid ([CoCl 2 ⋅ 6H 2 O]:[ChCl]) bearing cobalt‐containing anions resulted in a remarkable enhancement of the power factor to 76.8 μW m −1 K −2 . This IL combines the influence of a high‐boiling polar organic solvent and diffusing ions. A high σ mainly resulted from the efficient removal of PSS chains, ordering of the structure and delocalization of bipoloran‐dominant transport after conformational change. The increase in S was not due to dedoping of PEDOT chains, but rather the sharp feature of the density of states at the Fermi level induced by ion‐exchange with unconventional anions.