Electrochromic performances of poly(Azure A) films from digital video-electrochemistry (DVEC)

Poly(Azure A) (PAA) films doped with sodium dodecyl sulfate (SDS) were grown on transparent indium tin oxide (ITO) glass substrates by cyclic voltammetry. The electrochromism of PAA was investigated by digital video-electrochemistry (DVEC). DVEC consists of the acquisition of sequential digital images during the electro-stimulated changes of PAA color. The evolution of red, green, and blue (R, G, B) colors intensity (I) of analyzed pixels provides enough sensitivity to detect changes of some nmol cm−2 of electroactive centers. Besides, the different time evolution of these color intensities can serve to discern among different electroactive centers activated in the polymer. For the first time, contrast, coloration efficiency, and bleaching times of PAA are calculated by DVEC. The coloration efficiencies were between 15–25 cm2 mC−1 with short response times for the bleaching process between 2.9 and 5.5 s. PAA has good electrochromic performances to be used in electrochromic devices. Our present work provides an important insight into the design principles for a practical application of DVEC to characterize electrochromic devices in light-controlled conditions allowing us to find the best performances of these materials.