Avoiding Voltage-Induced Degradation in PET-ITO-Based Flexible Electrochromic Devices.

The cycling stability of flexible electrochromic devices (ECDs) under humid atmospheres is limited by irreversible indium tin oxide (ITO) reduction. A strategy to limit this degradation was developed and tested for model ECDs based on a sidechain-modified poly(3,4-ethylene dioxythiophene) (PEDOT) derivative and Prussian blue (PB). This work reveals that the cycling stability is reduced by dissolution of the ITO thin films and formation of metallic indium particles on the surface of the ITO layers.