Bifunctionalized polyamides based on quinoxaline structure for durable electrochromic display and memory storage

With the aim to obtain multifunctional durable electrochromic (EC) devices, we propose an effective strategy by introducing weak electron acceptor segment with suitable bandgap and oxidation potential. A series of quinoxaline-based units polyamides (PAs) (denoted as T₂BPA-CA, T₂BPA-OA, T₂BPA-TP, and T₂BPA-SA) were prepared from a novel donor–acceptor-donor (D-A-D) type diamine with weak electron acceptor quinoxaline and connected with two methoxyl-substituted donor triphenylamine, 10,13-bis[4-aminophenyl (4-methoxyphenyl) amino]-dibenzo[a,c]phenazine, and four dicarboxylic acids, which are high soluble in various organic solvents and exhibit excellent thermostability. Furthermore, the T₂BPA-SA thin film exhibits excellent EC performance with outstanding optical contrast (50 %), high coloration efficiency (230 cm² C⁻¹) and impressive cycle stability (optical contrast remains 80 % over 1400 cycles) in the NIR range. Meanwhile, all of these PAs are served as memristors and exhibit typical nonvolatile ternary memory, realizing an accessible threshold voltage of −0.65 V, a retention time of more than10⁴ s and high current switch ratio (10^3.52:10^2.43:1). Overall, this work implies the great potential of these PAs in EC displays and memory storage devices.