Electrochromic properties of conducting polymer metal nanoparticles composites

Electrochromic devices were made using a nanocomposite blend of conducting polymer poly(3,4 ethylenedioxythiophene):poly styrene sulfonate (PEDOT:PSS) and metal nanoparticles of silver or gold. Microscopic analysis showed a random distribution of metal nanoparticles with little aggregation in the matrix. The two terminal devices exhibited an increase in absorption that is dependant on the loading of nanoparticles in the polymer. Further, the active electrochromic spectral window showed a bias dependant tuning and a broadened spectral response. All devices exhibited slow relaxivities which we interpret as resulting from the high capacitance of the metal nanoparticles embedded in the polymer matrix.