A novel organic electrochromic device with hybrid capacitor architecture towards multicolour representation

Despite the application of electrochromic (EC) technologies in various optical modulating devices, the challenge to achieve multicolour EC behavior in a single device still remains. However, because almost all EC materials exhibit a single colour change, only a few organic materials are able to undergo multiple colour switching within a single device. The development of multicolour EC applications is therefore highly limited. In this research, we fabricated an EC device (ECD) with the simple hybrid capacitor architecture, i.e. with a flat ITO electrode as the working side and an ITO particle-modified electrode as the counter side. We also employed an electrolyte containing both anodic and cathodic EC materials consisting of small organic molecules. In this novel ECD, each EC material successfully undergoes individual colour switching from light yellow to light green and magenta. The mechanism of a multicolour system represents a significant breakthrough towards a full-colour ECD, thereby expanding the potential of EC technology.