Developing electrochromic polymers (ECPs) for application in smart windows is highly desirable in the electrochromic field. However, most ECPs present weak solar irradiance regulation due to the inverse visible and NIR modulation. Herein, three donor-acceptor polymers containing 4,7-bis(4-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole (HT-TZ) units are synthesized via direct arylation polymerization (DArP) method, and two copolymers with similar structure are prepared by electrochemical copolymerization for comparison. The copolymers synthesized by the DArP method present weak visible and high NIR modulation with an average visible (380 nm–780 nm) contrast below 15 % and NIR (750 nm–1400 nm) contrast above 60 %, inducing a high solar heat gain coefficient (SHGC) difference above 0.2 between the neutral and oxidized states, which is much higher than the reported high-performance ECPs. Additionally, these synthesized copolymers also present good electrochromic properties such as good stability and normal coloration efficiency, confirming their broad application potential in smart windows.

中文翻译：

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具有显着近红外调制作用的供体-受体电致变色聚合物的设计与合成


开发用于智能窗户的电致变色聚合物（ECP）在电致变色领域非常受欢迎。然而，由于反向可见光和近红外调制，大多数 ECP 的太阳辐照度调节较弱。在此，通过直接芳基化聚合（DArP）方法合成了三种含有4,7-双（4-己基噻吩-2-基）苯并[c][1,2,5]噻二唑（HT-TZ）单元的供体-受体聚合物，并通过电化学共聚制备了两种结构相似的共聚物进行比较。通过 DArP 方法合成的共聚物呈现弱可见光和高近红外调制，平均可见光 (380 nm–780 nm) 对比度低于 15%，近红外 (750 nm–1400 nm) 对比度高于 60%，从而产生高太阳得热系数（SHGC）中性态和氧化态之间的差异超过0.2，远高于报道的高性能ECP。此外，这些合成的共聚物还表现出良好的电致变色性能，例如良好的稳定性和正常的着色效率，证实了它们在智能窗中的广泛应用潜力。