Influence of side chains on electrochromic properties of green donor–acceptor–donor polymers |
| |
Authors: | Stefan Hellström Tianqi Cai Olle Inganäs Mats R Andersson |
| |
Affiliation: | aDepartment of Chemical and Biological Engineering, Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden;bSchool of Materials Science and Engineering, East China University of Science and Technology, Meilong Road 130, 200237 Shanghai, China;cBiomolecular and Organic Electronics, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden |
| |
Abstract: | Three solution processable cathodically coloring green electrochromic polymers, based on 2,3-diphenyl-5,7-di(thiophen-2-yl)thieno3,4-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 ΔT 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. |
| |
Keywords: | Electrochromism Conjugated polymer FeCl3-polymerization Spectroelectrochemistry MALDI-TOF |
本文献已被 ScienceDirect 等数据库收录! |
|