Electrochromic behavior of Ni-W oxide electrodes

A new electrochromic material, NI-W oxide, was fabricated by a reactive sputtering method and the effects of tungsten concentration in Ni-W oxide thin films on the: electrochromic behavior were investigated. It has been found that the charge transfer resistance which has been known to be very high in NiOx becomes significantly low with the addition of tungsten in NiOx. It turned out that the charge transfer density during the cyclic voltammetry increased considerably with the addition of tungsten in NiOx such that at an optimum concentration of tungsten (atomic ratio of W/NI = 0.33), a fast optical switching with the insertion and removal of lithium in Ni-W oxide thin films could be expected. The electrochromic display device composed K0.3WO3.15 and Ni-W oxide was fabricated and its optical switching characterized.