Electrochromic nanostructures grown on a silicon nanowire template

Vertically grown Si nanowires were prepared as a nanotemplate for conducting polymers. Electrochromic (EC) PEDOT (poly(3,4-ethylenedioxythiophene)) layer was successfully grown on Si nanowires by electrochemical polymerization method to form PEDOT nanowires having average wall thickness of ∼60 nm. As-prepared conductive nanowire electrode was applied to a low voltage working EC device by fabricating an all solid state EC device. The EC properties of the device were enhanced in the nanowire structure, showing reversible fast optical transition by applying ±2 V. The response time (tR) of the EC device from the PEDOT grown on Si nanowires was ∼0.7 s, which was much faster than that from PEDOT film coated on ITO glass electrochemically (tR=1.9 s).