The activation process through a bimodal transmittance state for improving electrochromic performance of nickel oxide thin film

In this study, we investigated the potential of using nickel oxide (NiO)-lithium phosphorous oxynitride (LiPON) composite as an anode electrode in electrochromic devices and evaluated the effect of Li+ insertion (or extraction) kinetics and diffusion of Li+. NiO-LiPON composite thin films were fabricated using the RF magnetron co-sputtering method. Here, we observed, for the first time, the bimodal colored states of the NiO-LiPON composite. This was caused by reacting both Ni metal and LiO under extremely cathodic condition, which enhanced the electrochromic properties - electrochromic response time and optical modulations - of the device. We also found that the NiO-LiPON composite thin films displayed long term stability. (C) 2012 Elsevier B.V. All rights reserved.