Tetrazole- and 1,3,4-oxadiazole-containing polydithienylpyrroles as potential smart organic coatings for multicolored electrochromic devices

Tetrazole and 1,3,4-oxadiazole rings were incorporated as pendant groups into dithienylpyrroles derivatives (TET, ON, and OP). The corresponding polymer films , P(TET), P(ON), and P(OP), were electrochemically deposited onto indium tin oxide (ITO)-coated glass substrates. These films exhibited multicolored electrochromism with reversible switching between oxidized and reduced states. The P(TET) film displayed distinct color variations at specific applied voltage: light khaki at −0.8 V, olive green at 0.4 V, mustard at 1.2 V, and aquamarine at 1.4 V. The transmittance change (∆ T ) and coloration efficiency of the P(TET) film were determined as 68.4 % and 220.4 cm 2 C −1 at 999 nm, respectively. A dual-layer P(OP)/PPro-Bz 2 electrochromic device (ECD) showed high Δ T (51.7 %) and a high coloration efficiency (702.0 cm 2 C −1 ) at 627 nm. Optical memory results confirmed that the colored and bleached states of the ECDs remained stable without power consumption. This study contributes to the advancement of dual-layer ECDs, offering potential applications in enhancing visual comfort for vehicle displays. • Tetrazole- and oxadiazole-containing polydithienylpyrroles are electrosynthesized. • P(TET) is olive green, mustard and aquamarine at 0.4, 1.2 and 1.4 V, respectively. • The transmittance change of the P(TET) film is determined as 68.4 % at 999 nm. • The P(ON)/PPro-Bz 2 ECD reveals a high Δ T of 51.5 % at 620 nm.