Polaron hopping mechanism of conducting polymer

To investigate the polaron hopping mechanism, thin films of polyaniline with solvent and without solvents were deposited over the surface of Al thin film and electrical properties were evaluated as a function of temperature ranging from - 60°C to 60°C. It was observed that all devices followed Arrhenius response of conductivity within given temperature range. The pre-exponential factor of conductivity and activation-energy for each device were found interrelated with isokinetic temperature (Meyer-Neldel Temperature) according to the Meyer-Neldel rule (MNR). It was examined that the solvent provides higher value of isokinetic temperature and lower value of activation energy, which may be due to the enhancement of solvent-induced crystallization, improvement of electronic energy transfer rate between molecular chains and softening of molecular vibration in polymer chains. The results demonstrate that IPA offers superior solvent response as compared to acetone for PANIEB matrix. The understandings obtained from this study will improve our knowledge for both the origin of MNR and the thermal-activated charge transport mechanism for conducting polymer in the presence of solvent.