Electrical and Optical Properties of Poly(<i>p</i>-phenylene) Film and Their Doping Effect

Abstract

Poly( p -phenylene) films with a conductivity of ca . 100 S/cm are synthesized by a new method of electrical oxidation of benzene using the composite electrolytes of CuCl 2 /LiAsF 6 . An in situ study of the absorption spectra of the poly( p -phenylene) films during the electrochemical doping with AsF 6 has been carried out. From the absorption spectrum of undoped state, we find a strong absorption peak at ca . 3.4 eV which is associated with the transition from ground-state to excited-state. The remarkable changes of the absorption spectra below the photon energy of 3.0 eV are observed, which are related to the polaron and/or bipolaron states of this polymer. The electrochemical n -type doping is also demonstrated.