Structural and electrochromic property control of WO3 films through fine-tuning of film-forming parameters

Abstract

Abstract Tungsten trioxide (WO3) films, extensively investigated for their remarkable electrochromic properties, have proven to be highly versatile in numerous applications. However, the challenge of achieving large-scale WO3 films with substantial dimensions and volumes remains a critical obstacle for industrial-scale production. Among the available techniques, magnetron sputtering stands out as the most efficient and straightforward method for the industrial preparation of WO3 films. In this comprehensive study, we meticulously explored the impact of various process parameters in magnetron sputtering on the film formation properties. By employing a controlled variable approach, we systematically investigated the influence of gas flow (Ar), sputtering pressure, power, and time. Our meticulous observations revealed that each parameter exerted distinct effects on the intricate film formation process. Careful analysis of the final dataset unequivocally demonstrated that when the sputtering conditions were meticulously optimized, the resulting films exhibited an extraordinary maximum transmittance change of 85% at a specific wavelength of 0.6 μm. Furthermore, these films showcased rapid coloring and bleaching response times, clocking in at an impressive 15 and 20 s, respectively, without any significant degradation even after undergoing 5,000 cycles. These groundbreaking findings provide invaluable insights into the intricate film formation process associated with magnetron-sputtered WO3.