Performance of chromophore-type electrochromic devices employing indium tin oxide nanorod optical amplification

In this study, we used transparent and conductive indium tin oxide (ITO) nanorods, prepared through electron-beam evaporation onto ITO glass substrates, as electrodes for viologen-based electrochromic devices (ECDs). Although the shapes of these ITO nanorods could be controlled simply by manipulating the evaporation time, they always maintained their high optical transmittance. Scanning electron microscopy images revealed that the ITO rods were uniformly distributed on the ITO glass; they had large surface areas for the tethering of electrochromic molecules. As a result, the ITO nanorods functioned as optical amplifiers in the viologen-based ECDs, increasing the color contrast [ΔT (%)] from 38% to 61%.