Pulsed laser deposition of (WO3)1 − x(Nb2O5)x thin films: Characterization and gasochromic studies

A series of (WO3)1 − x(Nb2O5)x (x = 0, 0.05, 0.1 and 0.15) mixed oxide films were fabricated by pulsed laser deposition (PLD) at 27 Pa oxygen partial pressure on ITO glass substrates. The thickness of the (WO3)1 − x(Nb2O5)x thin films is about 350 ± 30 nm and their surface has a uniform morphology. A layer of platinum (Pt) was then sputtered onto the surface of the film. The hydrogen gas sensing performance of Pt catalyst activated (WO3)1 − x(Nb2O5)x thin films were investigated. The cycling of the coloration was obtained from UV–vis spectra. Gasochromic coloration of (WO3)1 − x(Nb2O5)x thin films were investigated at room temperature in H2–N2 mixtures containing 1–100 mol% of H2. The results show that the shortest response time of (WO3)1 − x(Nb2O5)x/Pt hydrogen sensor is within 30 s and the highest transmittance change (ΔT) varies from 20% to 30%.