Silver-doped vanadium oxide electrochromic device by high-power impulse magnetron sputtering

Ag-doped V₂O₅ electrochromic (EC) thin films were fabricated on ITO-glass substrates using high-power impulse magnetron sputtering (HiPIMS). The films were deposited on ITO-coated glass substrates using high-power impulse magnetron sputtering (HiPIMS), an emerging physical vapor deposition technique. Silver nanoparticles were incorporated into the V₂O₅ layer with varying deposition durations (40, 50, and 60 seconds) to study the effect of silver content on the electro-optical properties of the coatings. X-ray photoelectron spectroscopy (XPS) confirmed the formation of stoichiometric V₂O₅ under an optimized oxygen-to-argon gas ratio of 30% during HiPIMS deposition. Both metallic and oxidized states of silver were detected on the film surfaces. X-ray diffraction (XRD) revealed polycrystalline V₂O₅ and the presence of metallic Ag, with silver particle sizes increasing from 24 nm to 44 nm as the doping level increased. The influence of silver incorporation on the surface morphology and EC performance was systematically investigated. FESEM analysis revealed a time-dependent morphological evolution of Ag nanoparticles, transitioning from well-dispersed spherical particles to larger coalesced structures as deposition time increased. UV–Vis measurements demonstrated notable optical transmittance modulation at 560 nm, with ΔT values of 34.7%, 36.4%, and 35.8% for AV1, AV2, and AV3 samples, respectively. The switching times for coloration and bleaching were 9.6–11.0 s and 7.2–8.5 s, respectively. Coloration efficiency values of 40.7–43.0 cm² C⁻¹ confirmed enhanced electrochromic activity upon Ag incorporation. The improved performance is attributed to optimized nanoparticle–oxide interaction and plasmon-assisted charge transfer. These results highlight the potential of Ag/V₂O₅ nanocomposite coatings for high-performance EC applications in smart window technologies.