Study of Novel WO_3-PEDOT:PSS Bilayered Thin Film for Electrochromic Applications

摘要

In this paper we report novel bilayered WO_3-PEDOT:PSS films synthesized for electrochromic device (ECD) applications. The films show synergetic properties of both WO_3 and PEDOT:PSS. Absorbance spectra reveals the dominance of the optical properties of PEDOT:PSS over WO_3 and the formation of polaron/bipolaron bands with change in potential. The fractal concept has been used to calculate the fractal dimensions of the reaction sites. The WO_3-PEDOT:PSS thin films exhibit excellent cathodic electrochromism with transmittance modulation of 63%, response times of 5.71/5.59 s in their color/bleach state and enhanced electrochromic coloration efficiency of 74.60 cm~2/C compared to that of pure WO_3 (47 cm~2/C) thin films. Colorimetric analysis shows that the curve on the chromaticity diagram follows a linear trajectory on the application of varying reduction potential.