Doping dependent transport properties of polyaniline-CSA films

Polyaniline films prepared via the camphorsulfonic acid (CSA)/m-cresol solution processing route have been synthesised with doping levels in the range 10 to 90 %. The electrical conductivity of these films has been measured as a function of temperature between 10 and 300 K. Films with a doping level of over 30 % are seen to exhibit metallic conductivity, with the 60 % doped films having metallic characteristics down to 135 K and room temperature conductivities of 300 +/- 30 Scm(-1). The conductivity of stretch oriented 60 % doped films has also been studied as a function of temperature, with a peak conductivity measured as 583 Scm(-1). The results are modelled in terms of a heterogeneous model of fluctuation induced tunnelling (FIT) and metallic transport.