Thickness dependent tungsten trioxide thin films deposited using DC magnetron sputtering for electrochromic applications

Abstract

DC magnetron sputtering was used to grow tungsten oxide (WO3) thin films on FTO and corning substrates. SEM, XRD, Electrochemical Analyzer, and UV–Vis Spectrometer were used to analyze surface morphology, structural properties, electrochromic characteristics, and optical characteristics. At an 800 nm wavelength, a decrease in thin-film thickness increased optical transmittance from 87 % to 95 %. Furthermore, coloring efficiency was observed to vary with the thickness of thin films for both 500 nm and 375 nm are 10.34 cm2 C-1 to 18.57 cm2 C-1. In comparison to the high-thickness thin film, the lesser-thickness deposited nano-thin film has a higher diffusion coefficient. At 8 × 10-4 mbar partial pressure, the diffusion coefficients for the smaller and the high-thickness thin film are 7.28x10-14 cm2s−1 and 6.0x10-14 cm2s−1, respectively. The diffusion coefficient and coloring efficiency have been found to have a considerable influence on the thickness and surface-to-volume ratio, which could be important in electrochromic applications.