Synthesis and electrochromic properties of all donor polymers containing fused thienothiophene derivatives with high contrast and color efficiency

• Published in: Polymer (Guilford) Vol. 261; p. 125404
• Main Authors: Wu, Lei, Guo, Yafei, Kuang, Guoqiang, Wang, Yi, Liu, Hua, Kang, Yue, Ma, Tian, Tao, Yijie, Huang, Kaibing, Zhang, Shiguo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 18.11.2022
• Subjects: 3,4-Dialkyloxythiophene; Conducting polymers; Electrochromism; Tris(thienothiophene); Conducting polymers; Electrochromism; Tris(thienothiophene); 3,4-Dialkyloxythiophene
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2022.125404

Synthesis of high-performance electrochromic polymers is still one of the research highlights in electrochromic field. In this work, four solution-processable electrochromic polymers based on fused thienothiophene derivative (tris(thienothiophene) (TTT)) or indacenodithieno[3,2-b]thiophene (IDTT)) and 3,4-dialkyloxythiophene derivative (3,4-ethylenedioxythiophene (EDOT) or 3,4-propylenedioxythiophene (ProDOT)) are successfully synthesized via direct arylation random polymerization (DArP) with a low reaction temperature to decrease the β-coupling. H Nuclear magnetic resonance (HNMR), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), Cyclic voltamogram (CV), and spectroelectrochemistry are applied to characterize these four polymers. These four polymers present colored-to-highly transmissive electrochromic performance, while the IDTT-based polymers give red-to-transmissive color change range and TTT-based polymers can change from blue to highly transmissive. All these four polymers present high optical contrast (>45%), fast switching response, good stability, and high coloration efficiency. Two electrochromic devices fabricated based on these prepared polymers confirm the excellent electrochromic performance of these polymers in devices. [Display omitted] •Four solution-processable electrochromic polymers containing fused thienothiophene units are synthesized via direct arylation polymerization.•These synthesized polymers present excellent electrochromic properties such as vivid color change, high optical contrast, and good stability.•The assembled ECDs retain the electrochromic properties of the synthesized polymers with improved bleaching speed.