Preparation of amorphous TiO2 films by RF magnetron sputtering: Process optimization and effect of sputtering pressure on electrochromic properties

In this study, radio frequency (RF) magnetron sputtering was utilized to fabricate Titanium dioxide (TiO2) thin films at a room temperature. Scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, electrochemical workstation, and UV-Vis spectrophotometry were employed to analyze and characterize the microstructure, compositional components, and electrochromic properties of the films. The main focus is on exploring the microstructure and electrochromic properties of films produced under diverse sputtering pressures. The results show that the TiO2 films fabricated at a sputtering pressure of 1.2 Pa exhibit the most desirable surface morphology, with an optical modulation amplitude of up to 49.18 % (@550 nm), coloring time of 1.28 s, bleaching time of 0.79 s, and a coloration efficiency of 21.07 cm2/C. After 1000 cyclic voltammetry tests, the Q decay rate is 51.75 %. Electrochemical impedance spectroscopy (EIS) measurements reveal that TiO2 films prepared under these process parameters have lower charge transfer resistance and ion diffusion impedance, which facilitate ion injection and extraction.