Electrochromic properties of NiO :H films deposited by DC magnetron sputtering for ITO/NiO :H/ZrO2/WO3/ITO device

• DOI: 10.1016/j.apsusc.2015.09.056
• Publication Date: 2015-09-08T16:01:25Z
• Authors: Dongmei Dong; Wenwen Wang; Guobo Dong; Yuliang Zhou; Zhonghou Wu; Mei Wang; Famin Liu; Xungang Diao
• Keywords: Non-blocking I/O

Abstract NiOx:H thin films were deposited on ITO-coated glass by DC reactive magnetron sputtering at room temperature. The effects of the hydrogen content on the structure, morphologies, electrochemical properties, the stoichiometry and chemical states of NiOx:H thin films were systematically studied. In X-ray diffraction and atomic force microscopy analysis, the crystallinity of the films tends to be weakened when the flow amount ratio of Ar:O2:H2 equals 19:1:3 and as confirmed in electrochemical analysis, such relatively weak crystallinity is the main contributing factor to ion transportation. X-ray photoelectron spectroscopy reveals that the increase of the hydrogen contents results in a relatively lower binding energy exhibited in the Ni 2p spectra. The proportion of Ni2O3 in NiOx:H films increases from 22% at bleached state to 33% at colored state. A monolithic all-thin-film inorganic electrochromic device was fabricated with complementary configuration as ITO/NiOx:H/ZrO2/WO3/ITO. The electrochromic device with optimized NiOx:H thin films acting both as ion storage layer and proton-providing source displays high modulation efficiency of 68% at a fixed wavelength 550 nm.