Abstract
A very high conductivity of polyaniline (PANI) salts can be achieved but different authors provide different explanations of the conduction mechanism. To clarify the problem, we studied the contribution of each type of charge to the total conductivity.
The conductivity (1.9-3.5) S cm(-1) was found using ohmic gold contacts on a PANI sample applied to glass. In contrast, the conductivity of 8.0 x 10(-7) S cm(-1) was determined from the voltampere characteristic measured on the Au/PANI/Si/In structure in a sandwich configuration.
The impedance spectra show that in this structure only polarons and holes participate in the charge transfer while ions only cause sample polarization. Conductivity of 3 x 10-7 S cm(-1) caused by ions was determined from the dielectric spectra.
Since the sum of all contributions is very low compared to the measured total conductivity, a new mechanism of conductivity is proposed that explains the importance of hydrogen and chlorine molecules for charge transfer.