Electrochemical properties and photoelectrochemical response of vacuum-deposited poly(p-phenylene) thin films

The electrochemical properties of a poly(p-phenylene) (PPP) thin film prepared by vacuum deposition were investigated by cyclic voltammetry in organic and aqueous media with a lithium perchlorate electrolyte. The PPP thin film was able to undergo both n-doping and p-doping reversibly. In an aqueous medium, the cyclic voltammograms indicated the characteristic loop in a potential sweep. The loop was ascribed to the charge transfer on the PPP film surface and to an accumullation effect of the charge in the PPP film. A photocurrent was observed at the PPP film under UV light irradiation.