Influence of side chains on electrochromic properties of green donor-acceptor-donor polymers
Artikel i vetenskaplig tidskrift, 2011

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.

neutral state

distributions

realization

Conjugated polymer

copolymers

processable green

maldi-ms

polymerization

design

MALDI-TOF

Spectroelectrochemistry

FeCl3-polymerization

solar-cells

oxidized state

Electrochromism

Författare

Stefan Hellström

Chalmers, Kemi- och bioteknik, Polymerteknologi

Tianqi Cai

East China University of Science and Technology

Chalmers University of Technology

Olle Inganäs

Linköpings universitet

Mats Andersson

Chalmers, Kemi- och bioteknik, Polymerteknologi

Electrochimica Acta

0013-4686 (ISSN)

Vol. 56 3454-3459

Ämneskategorier

Kemi

DOI

10.1016/j.electacta.2010.11.018