Electrochromic Properties of Li- Doped NiO Films Prepared by RF Magnetron Sputtering
Jui-Yung Chang, Ying‐Chung Chen, Chih-Ming Wang, Youwei Chen
Abstract
In this study: various amounts of Li2CO3 powders were mixed into NiO powders to fabricate the Li- added NiO (NiO:Li) targets. The electrochromic films of LiNiO were deposited on ITO glasses at room temperature (R.T.) by RF magnetron sputtering. The thicknesses of electrochromic LiNiO films were kept about 200 nm. The ECD device was constructed with structure of Glass/ITO/ LiNiO /Gel-electrolyte/ITO/Glass. The results indicated that the optimal electrochromic characteristics of Li0.16Ni0.58O thin films could be obtained by 10 wt% Li2CO3 added NiO target. The optimized characteristics of ECDs could be achieved with the intercalation charge (Q) of 11.93 mC/cm2, the optical density (ΔOD) of 0.38, the transmittance change (ΔT) of 44.1%, and the coloring efficiency (η) of 31.8 cm2/C at the wavelength of 550 nm by setting voltage of 3.2V. The results demonstrate that the doping of Li+ ions into NiO films can effectively enhance the characteristics of ECD devices. The reason may due to the increased amount of charge stored in the electrochromic devices (ECDs).