Applications of Copolymers Consisting of 2,6-di(9H-carbazol-9-yl)pyridine and 3,6-di(2-thienyl)carbazole Units as Electrodes in Electrochromic Devices

Chung-Wen Kuo; Jui-Cheng Chang; Yu-Ting Huang; Jeng-Kuei Chang; Li-Ting Lee; Tzi-Yi Wu

doi:10.3390/ma12081251

Applications of Copolymers Consisting of 2,6-di(9H-carbazol-9-yl)pyridine and 3,6-di(2-thienyl)carbazole Units as Electrodes in Electrochromic Devices

Materials (Basel). 2019 Apr 16;12(8):1251. doi: 10.3390/ma12081251.

Authors

Chung-Wen Kuo¹, Jui-Cheng Chang², Yu-Ting Huang³, Jeng-Kuei Chang⁴, Li-Ting Lee⁵, Tzi-Yi Wu⁶

Affiliations

¹ Department of Chemical and Materials Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 80778, Taiwan. welly@nkust.edu.tw.
² Bachelor Program in Interdisciplinary Studies, National Yunlin University of Science and Technology, Yunlin 64002, Taiwan. d700215@gmail.com.
³ Department of Chemical and Materials Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 80778, Taiwan. a3473179@gmail.com.
⁴ Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan. jkchang@nctu.edu.tw.
⁵ Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan. ltlee@fcu.edu.tw.
⁶ Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin 64002, Taiwan. wuty@gemail.yuntech.edu.tw.

Abstract

A series of carbazole-based polymers (PdCz, P(dCz2-co-dTC1), P(dCz2-co-dTC2), P(dCz1-co-dTC2), and PdTC) were deposited on indium tin oxide (ITO) conductive electrodes using electrochemical polymerization. The as-prepared P(dCz2-co-dTC2) displayed a high ΔT (57.0%) and multichromic behaviors ranging from yellowish green, greenish gray, gray to purplish gray in different redox states. Five organic electrochromic devices (ECDs) were built using dCz- and dTC-containing homopolymers and copolymers as anodic materials, and poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProdot-Me₂) as the cathodic material. The P(dCz2-co-dTC2)/PProdot-Me₂ ECD presented remarkable electrochromic behaviors from the bleached to colored states. Moreover, P(dCz2-co-dTC2)/PProdot-Me₂ ECD displayed a high optical contrast (ΔT, 45.8%), short switching time (ca. 0.3 s), high coloration efficiency (528.8 cm² C^-1) at 580 nm, and high redox cycling stability.

Keywords: coloration efficiency; copolymer; electrochromic device; electrochromic material; redox stability; spectroelectrochemistry.