The colored and bleached properties of tungsten oxide electrochromic films with different substrate conductivities

Tungsten oxide films have been deposited by reactive RF magnetron sputtering. The electrochromic properties were characterized by cyclic voltammetry and UV–visible spectrometry. The oxide films were deposited on substrates with different electrical conductivities. The sheet resistances of the ITO electrodes used in this study were 10, 50 and180 Ω/cm2, respectively. Experimental results demonstrate that the electrical conductivity of the electrode material strongly influences the response time of the WO3 electrochromic film, which is explained by the different numbers of lithium ions transported at the different electrode conductivities. The ITO material with 10 Ω/cm2 gave the best response time of the WO3 electrochromic films.