Applied voltage dependence of electrochromic properties in tungsten oxide thin films prepared by direct current reactive magnetron sputtering

Abstract

A typical EC material, WO₃ was deposited at a high pressure of 3 Pa to form a sparse film structure in which Li cations were easily injected. In a previous study, 500 nm film thickness samples showed a stable decolorization, however, 1000 nm film thickness films did not completely decolorize, suggesting the retention of cations injected into the deep trap. In the present study, to suppress the injection of cations into the 1000 nm thick film, the applied voltage at the time of cations injection was varied, and the transmission spectrum and the amount of transferred charge at the time of coloring and decoloring were compared.