All-thin-film inorganic complementary electrochromic devices with the novel self-aligned lithium-rich ion conductor

Abstract An all-thin-film inorganic complementary electrochromic device (ECD) with the novel self-aligned lithium-rich ion conductor has demonstrated. The 80nm-thick self-aligned lithium-rich ion conductor has formed between the WO3 electrochromic layer and Li:Ta2O5 ion conductor during the device activation process and confirmed with the transmission electron microscope image. Furthermore, the energy-dispersive X-ray spectroscopy element map also provides the ECD composition distribution analyses. Although the ion mobility extracted with the activated ECD has showed a decrease from 4.47 × 10−9 cm2/Vs to 1.86 × 10−10 cm2/Vs, the ion conductivity has increased from 9.12 × 10−9 S/cm to 2.95 × 10−8 S/cm due to the increase of ion concentration. The increase of the ion concentration could be related to the presence of the lithium-rich ion conductor. As a result, the fast colored switching time of the ECD in this study is mainly due to the self-aligned lithium-rich ion conductor, which has directly provided the nearest Li-ion source for the WO3 layer.