Influence of side chains on electrochromic properties of green donor-acceptor-donor polymers
2011 (English)In: ELECTROCHIMICA ACTA, ISSN 0013-4686, Vol. 56, no 10, 3454-3459 p.Article in journal (Refereed) Published
Three solution processable cathodically coloring green electrochromic polymers, based on 2,3-diphenyl-5,7-di(thiophen-2-yl)thieno[3,4-b]pyrazine, have been synthesized by oxidative FeCl3 polymerization. The polymers were designed with solubilizing alkyl and oligoethylene oxide side chains to achieve solubility and processability. All three polymers have a small electrochemical bandgap (1.8-1.9 eV) and low oxidation potentials. Spectroelectrochemical studies of polymer films on ITO reveal that the alkyl side chains in head-to-head position on the polymer backbone promote a defined high-energy absorption peak and suppress tailing of charge-carrier absorption into the visible region. Kinetic studies, based on transmission measurements applying a square-wave potential between reduced and oxidized states, show that the polymer with exclusively oligoethylene oxide side chains (P3) had the fastest response times, monitored at the low-energy absorption maxima. The best performing polymer (P1) showed a good optical contrast in the visible region with a Delta T of 26% at 700 nm. An initial test of the electrochemical stability showed that the oligoethylene oxide containing polymers had superior stability over 500 full switches.
Place, publisher, year, edition, pages
Elsevier Science B.V., Amsterdam. , 2011. Vol. 56, no 10, 3454-3459 p.
Electrochromism, Conjugated polymer, FeCl3-polymerization, Spectroelectrochemistry, MALDI-TOF
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-68227DOI: 10.1016/j.electacta.2010.11.018ISI: 000289964800007OAI: oai:DiVA.org:liu-68227DiVA: diva2:416855