Fig. 6. log–log plot of σ as a function of temperature from 3 to 300 K. Left Y axis: PEDOT:OTf (red squares) and PEDOT:Sulf (black circles); right Y axis: PEDOT:PSS (green triangles). Top inset: the corresponding activation energy W in a log–log plot. For PEDOT:Sulf, W is negative in the [3 K; 5.5 K] range, as expected for metallic behaviour. Bottom inset: magnified image of the electrical conductivity of PEDOT:Sulf in the [3 K; 20 K] range.
