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In this paper, the single-doped (Ni-WO 3 and Ti-WO 3) and binary-doped (Ni-Ag-WO 3 and Ti-Ag-WO 3) amorphous WO 3 thin films were respectively prepared on indium-doped tin oxide conductive glass substrates by radio-frequency magnetron sputtering. Among the single-doped WO 3 thin films, the electrochromic (EC) properties of films can be enhanced by the presence of Ni or Ti. However, the low conductivity of WO 3 limits its application in EC devices. A novel approach was proposed to ameliorate this disadvantage which has not been explored, that is, the highly conductive Ag was introduced into WO 3 films with Ni or Ti. The experimental results show that the addition of Ag reduces the charge transfer resistance and shortens the ion diffusion path length, thereby improving the EC response time (Ni-Ag-WO 3 : t b =1.16 s; Ti-Ag-WO 3 : t c =4.14 s), electrochemical active area, and ion diffusion coefficients (Ni-Ag-WO 3 : D a =3.032 × 10−9 cm2/s; Ti-Ag-WO 3 : D c =7.737 × 10−9 cm2/s). Based on these work, the feasibility of Ni-Ag and Ti-Ag binary-doped WO 3 films was confirmed. These discoveries contribute to the exploration of preparing high-performance WO 3 EC films for the practical applications of EC devices such as in automatic anti-glare rearview mirrors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly crystalline In 2 O 3 films are grown by pulsed reactive magnetron sputtering. • Substrate heating further improves the film crystallinity and conductivity. • 400 °C is the limit for benefiting to obtain the optimum crystallinity of In 2 O 3 films. • The films deposited at 400 °C yield the lowest resistivity of 1.28 × 10-4 Ω⋅cm. • An average transmittance of greater than 80% are also obtained at 400 °C. A transparent conductive oxide (TCO) should have a combination of high electrical conductivity and optical transmission property to fulfill the challenging demands of industrial applications. So far, doped TCOs have been mostly considered to fulfill the technological challenges. In this study, we demonstrate that indium oxide (In 2 O 3) thin films without intentional doping can be deposited with high crystallinity under specific film growth conditions leading to thin films with high mobility, high electrical conductivity, and high transmittance. In 2 O 3 thin films have been deposited by reactive pulsed direct current magnetron sputtering (pulsed DCMS) from an indium target on substrates in a temperature range from room temperature (RT) to 600 °C. Detailed investigations on In 2 O 3 thin films are performed and the film properties such as crystallinity, microstructure, chemical bonding states, electrical and optical properties are revealed. Enhanced plasma density and ionization degree provided by the employed reactive pulsed DCMS and the intentional substrate heating during the thin film deposition give possibility to deposit highly crystalline thin films which are preferentially oriented in (2 2 2) direction. The substrate heating enhances the crystallinity of the grown films up to a certain optimum temperature: 400 °C. When the substrate temperature is above 400 °C, the carrier concentration and mobility decrease due to the grain refinement effect caused by growth competition of grains in different orientations. The films grown at 400 °C indicate the presence of high oxygen vacancy concentrations, which can directly be associated with a high charge carrier concentration despite the lack of intentional doping. The undoped In 2 O 3 films in this study grown at 400 °C show highly promising and competitive electrical properties such as low resistivity of 1.28 × 10-4 Ω⋅cm and the high carrier mobility of 69 cm2/Vs. The average transmittance of the In 2 O 3 films with the highest conductivity is found to be greater than 80% in the visible to the near-infrared spectral region owing to an enhancement in the carrier mobility and an optical bandgap in the range from 3.61 eV to 3.77 eV. [ABSTRACT FROM AUTHOR]