Doping and conductivity studies on poly(p-phenylene vinylene)

Abstract We have investigated the doping and temperature dependence of the conductivity of poly( p -phenylene vinylene) (PPV) free-standing films. High conductivities and a very weak temperature dependence are obtained in sulfuric acid (H 2 SO 4 ) -doped PPV (10 4 S/cm), indicative of a metallic state, whereas iron trichloride (FeCl 3 )-doped samples are observed to be less conducting (10 3 S/cm) and insulating at low temperatures. Doping of PPV with triflic acid (CF 3 SO 3 H) results in a high conductivity as well. Conductivity as a function of stretching ratio is obtained in H 2 SO 4 -doped PPV. The stability of this system in air and moisture was also investigated. These features of PPV as a highly doped conducting polymer system are discussed and compared with previous studies of PPV and of polyacetylene.