Enhanced electrochromic characteristics induced by Au/PEDOT/Pt microtubes in WO3 based electrochromic devices

A study has been carried out on improving electrochromic performances of tungsten trioxide (WO3) thin films based electrochromic devices (ECDs) with inclusion of gold/poly (3, 4-ethylenedioxythiophene)/platinum (Au/PEDOT/Pt) microtubes. The deposited film characteristics were evaluated using scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS). SEM results indicated that homogeneous spreading of Au/PEDOT/Pt microtubes are successfully obtained onto the WO3 layer. The electrochromic performances such as electrochromic contrast, response times and charge transfer resistance were investigated and compared with Au/PEDOT/Pt microtubes-free system in detail. Higher optical contrast (26%) and faster response times (bleaching time (t(b)): 13.83 s, coloration time (t(c)): 19.25 s) were obtained for electrochromic device made from Au/PEDOT/Pt microtubes against an applied potential of +/- 2 V. Especially, Au/PEDOT/Pt microtubes-based ECD exhibited stronger electrochromic color change from transparent to blue.