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

[Display omitted] • Polyamides with D-A segments for electrochromic and memory storage performance improvements. • The triphenylamine moiety with substituted methoxyl group improves the switching cycle stability. • Polyamides exhibit high optical contrast, outstanding coloration efficiency, fast response and long-term cycle. • Polyamides also serve as memristors with accessible threshold voltage and long retention time. 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 T 2 BPA-CA, T 2 BPA-OA, T 2 BPA-TP, and T 2 BPA-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 T 2 BPA-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 (103.52:102.43:1). Overall, this work implies the great potential of these PAs in EC displays and memory storage devices. [ABSTRACT FROM AUTHOR]