Electrical conductivity of iodine-, iron chloride- and indium iodide-doped polyacetylene

Abstract The temperature dependence of the d.c. electrical conductivity of polyacetylene doped with iodine, iron chloride and indium iodide, respectively, is investigated and the influence of the dopant species and concentration is studied. It is found that for a rough characterization, in all cases σ ( T ) can be approximated by the phenomenological relation σ(T) ∼ σ 0 exp [−( T 0 T ) ν ] with ν ∼ 1 3 (fits with ν = 1 2 or ν = 1 4 not being significantly worse). In addition, there exists a strong correlation between σ 0 and T 0 . The results imply that the conductivity of doped polyacetylene cannot be described by the percolation of a stoichiometrically oxidized phase in an insulating matrix of pristine polymer.