Conductivity of silver exposed polypyrrole films

Electrochemically prepared conducting polypyrrole tosylate films were expos ed to silver in a wide range of concentrations. Four-probe measurements of the de conductivity of these films as well as two-probe ac conductivity mea surements were performed. Small silver exposures lead to a dramatic change in the surface potentials and electronic structure, whereas the ac- and de- conductivities appear not to be influenced. In the range of high silver exp osures metallic conductivities due to the formation of a massive silver ove rlayer on top of the polypyrrole films are observed. (C) 2001 Elsevier Scie nce B.V. All rights reserved.