Electrochromic Properties of LixNiyO Films Deposited by RF Magnetron Sputtering

Electrochromic properties of a series of Li x Ni y O films were studied to obtain the films that give a good reversible electrochromic reaction in a nonaqueous electrolyte solution. We paid attention to the lithium content in the films. The films were deposited by radio-frequency (rf) magnetron sputtering with Li x Ni y O targets under different conditions. The lithium contents were selected by using three different Li x Ni y O targets. NiO pellets were also used for cosputtering with the targets to finely adjust the lithium content in Li x Ni y O films. We found that a Li x Ni y O film gave a high electrochromic coloration efficiency when the lithium content in the film was adjusted to about 0.2. The X-ray diffraction (XRD) study showed that the crystalline Li 2 Ni 8 O 10 film yielded good electrochromic performance, and that the (102) XRD peak was dominant in the films. © 2009 The Electrochemical Society. [DOI: 10.1149/1.3141704] All rights reserved.