Comparison study of WO3 thin film and nanorods for smart window applications

The WO3 thin films were deposited at oxygen partial pressure of 8x10-4 mbar. A template-free straightforward hydrothermal method is employed to produce vertical alignment hierarchical WO3 nano-architectures on clear conducting substrates (3x2.5 cm2 in size and slides resistance 4 O). After being deposited at ambient temperature, the samples were air annealed at 400 °C for 4 h. The optical, electrochromic, surface and structural morphology behavior of the deposited material after annealing were studied using XRD, Raman, FTIR, SEM, electrochemical analyzer and UV–Visible spectrometer characterization methods. After annealing at 400 °C for 4 h in air, every characteristic peak are matched to a monoclinic (crystalline) WO3 phase. The Nano flower array achieved a considerable coloration efficiency (24.09 cm2/s) and low cathodic peak current (−2.03 mA) compare to the Tungsten trioxide thin film produced by the DC magnetron sputtering method. The vertically oriented geometry and the porosity space between the Nano flower, which improve H+ diffusion and provide a considerable contact area for charge-transfer processes, are primarily responsible for the improved electrochromic properties.