Electrochromic response in polypyrrole sensitized by Prussian blue

The electrochromic response of polypyrrole (PPy)/Prussian blue (PB) composite films has been studied in different electrolytes such as KCl, LiClO4, K2SO4, KNO3, KI/I2, etc., by depositing the Prussian blue films on top of the conducting polypyrrole films, both being prepared by an electrochemical method. The results show that the use of PB on PPy not only yields high contrast but also extends the electrochromic response to a wider region of the visible spectrum, thus working as a sensitizer for improving the electrochromic contrast of the conducting polypyrrole.