Structure and Temperature Dependence of Electrical Conductivity in Polythiophene Nanoparticles

Polythiophene (PTh) has been synthesized at three different temperatures by oxidation process with ferric chloride as an oxidizing agent. Samples were confirmed to be noncrystalline by XRD studies. SEM images showed an agglomeration of particles in the samples made at 278K and 305K and tubes like structures were observed for sample made at 323K. The optical absorption (UV-Vis) studies indicates two bands for PTh samples synthesised at 278K & 305K and three bands for the one made at 323K . Temperature dependence of DC conductivity has been measured and data analyzed using Mott’s small polaron hopping and variable range hopping models. Activation energies for DC conduction were determined. Density of states obtained by Mott’s(VRH) model fits were found to be quite high compared to elemental semiconductors and polymers.