1,4-Bis((9H-Carbazol-9-yl)Methyl)Benzene-Containing Electrochromic Polymers as Potential Electrodes for High-Contrast Electrochromic Devices

Chung-Wen Kuo; Jui-Cheng Chang; Li-Ting Lee; Yi-Dong Lin; Pei-Ying Lee; Tzi-Yi Wu

doi:10.3390/polym14061175

1,4-Bis((9H-Carbazol-9-yl)Methyl)Benzene-Containing Electrochromic Polymers as Potential Electrodes for High-Contrast Electrochromic Devices

Polymers (Basel). 2022 Mar 15;14(6):1175. doi: 10.3390/polym14061175.

Authors

Chung-Wen Kuo¹, Jui-Cheng Chang^{2

3}, Li-Ting Lee⁴, Yi-Dong Lin¹, Pei-Ying Lee², Tzi-Yi Wu²

Affiliations

¹ Department of Chemical and Materials Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 80778, Taiwan.
² Department of Chemical Engineering and Materials Engineering, National Yunlin University of Science and Technology, Yunlin 64002, Taiwan.
³ Bachelor Program in Interdisciplinary Studies, National Yunlin University of Science and Technology, Yunlin 64002, Taiwan.
⁴ Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan.

Abstract

Four 1,4-bis((9H-carbazol-9-yl)methyl)benzene-containing polymers (PbCmB, P(bCmB-co-bTP), P(bCmB-co-dbBT), and P(bCmB-co-TF)) were electrosynthesized onto ITO transparent conductive glass and their spectral and electrochromic switching performances were characterized. The PbCmB film displayed four types of color variations (bright gray, dark gray, dark khaki, and dark olive green) from 0.0 to 1.2 V. P(bCmB-co-bTP) displayed a high transmittance variation (∆T = 39.56% at 685 nm) and a satisfactory coloration efficiency (η = 160.5 cm²∙C^-1 at 685 nm). Dual-layer organic electrochromic devices (ECDs) were built using four bCmB-containing polycarbazoles and poly(3,4-ethylenedioxythiophene) (PEDOT) as anodes and a cathode, respectively. PbCmB/PEDOT ECD displayed gainsboro, dark gray, and bright slate gray colors at -0.4 V, 1.0 V, and 2.0 V, respectively. The P(bCmB-co-bTP)/PEDOT ECD showed a high ∆T (40.7% at 635 nm) and a high coloration efficiency (η = 428.4 cm²∙C^-1 at 635 nm). The polycarbazole/PEDOT ECDs exhibited moderate open circuit memories and electrochemical redox stability. The characterized electrochromic properties depicted that the as-prepared polycarbazoles had a satisfactory application prospect as an electrode for the ECDs.

Keywords: color-bleach kinetics; electrochemical redox stability; electrochromic device; electrosynthesis; redox process.