Neutral state black electrochromics are prominent materials for smart applications such as displays, car rear views, e-papers etc. This work has aimed to obtain a neutral state black electrochromic polymer, by tuning the optical absorbance to whole visible region. Two monomers, 4,7-bis(5-(thiophen-2-yl)thiophen-2-yl)benzo[c] [1,2,5]thiadiazole (TTBTT) and 3,4-ethylenedioxythiophene (EDOT), were selected according to their complementary absorbance behaviors, and they were combined in the same polymer backbone via electrochemical copolymerization technique. Copolymerization was performed using three different monomer feed ratios (2:1, 1:1 and 1:2 (EDOT: TTBTT)). Even though all the copolymers exhibited dark to transmissive colors from neutral to oxidized states, changing the monomer feed resulted in different optical contrast, switching response and color hues for each copolymer. The higher optical contrast (from 17% to 27%) and faster switching response (from 3.6 s to 1.8 s) were recorded as EDOT unit increase in the copolymer chain. A dual type electrochromic device was also constructed using the copolymer and the resulting device was successfully changed its color from black to transmissive.

中性态黑色电致变色材料是显示器、汽车后视镜、电子纸等智能应用的重要材料。这项工作旨在通过将光吸收调整到整个可见区域来获得中性态黑色电致变色聚合物。两种单体，4,7-双（5-（噻吩-2-基）噻吩-2-基）苯并 [c] [1,2,5] 噻二唑 (TTBTT) 和 3,4-乙撑二氧噻吩 (EDOT)根据它们互补的吸光度行为进行选择，并通过电化学共聚技术将它们组合在同一聚合物主链中。使用三种不同的单体进料比（2:1、1:1 和 1:2（EDOT：TTBTT））进行共聚。尽管所有共聚物都显示出从中性到氧化状态的深色到透射色，但改变单体进料会导致不同的光学对比度，每种共聚物的转换响应和色调。更高的光学对比度（从 17% 到 27%）和更快的切换响应（从 3.6 秒到 1.8 秒）被记录为共聚物链中 EDOT 单元的增加。还使用该共聚物构建了一种双型电致变色装置，并且所得装置成功地将其颜色从黑色变为透射。