A low-band gap conductive copolymer of bis-3-hexylthiophene substituted 4-tert-butylphenyl quinoxaline and 3,4-ethylenedioxythiophene

• Published in: Journal of solid state electrochemistry Vol. 14; no. 2; pp. 279 - 283
• Main Authors: Ozyurt, Funda, Durmus, Asuman, Gorkem Gunbas, E., Toppare, Levent
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-02-2010
• Subjects: Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Energy Storage; Original Paper; Physical Chemistry; Conductive copolymers; Electrochemical polymerization; Spectroelectrochemistry
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-008-0750-9

Electrochemical copolymerization of 2,3-bis(4-
tert
-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl)quinoxaline (HTQ) and 3,4-ethylenedioxythiophene (EDOT) was performed to fulfill a strategy in achieving fine-tuned electrochromic properties. The copolymer, P(HTQ-
co
-EDOT) was characterized via detailed studies of cyclic voltammetry and spectroelectrochemistry. Copolymer film has many superior properties compared to the parent homopolymer.
E
g
of the copolymer was calculated as 1.4 eV, which is substantially lower than the homopolymer’s (PHTQ) band gap, which was reported as 1.75 eV. Optical contrast of the resultant copolymer was shown to be 34%, which is nearly 10% higher than the PHTQ. The most striking achievement in the electrochromic properties was in switching times. The copolymer switches very rapidly between its neutral and the oxidized states and achieves a 34% optical contrast in less than 1 s, half of the value for the pristine polymer.