EFFECT OF MOLECULAR MASS OF POLY(3-ALKYLTHIOPHENE) ON ELECTRICAL-PROPERTIES

Fractionated precipitation of poly(3-octylthiophene) was used to prepare polymers with different molecular mass and molecular mass distributions. The molecular mass dependent processes of charge transport in these samples have been investigated. The temperature dependence of the electrical conductivity corresponds to the three-dimensional variable range hopping mechanism. The conductivity and the absorbance at interband transition increase with molecular mass, although the absorption edge is unchanged. These facts are interpreted in terms of an increase in the radius of a localized wavefunction with the molecular mass.