ELECTRON-TRANSPORT IN FE-DOPED POLYVINYL ACETATE FILMS

The electrical conductivity and current-voltage characteristics of pure and Fe3+-doped polyvinyl acetate films have been studied for various temperatures and bias field strengths. The activation energy for conduction showed an increasing trend with increasing dopant concentration. This has been attributed to the formation of molecular aggregates. The variation of electrical conductivity for doped films with temperature showed three regions with different activation energies. This behaviour has been explained in terms of the type of conduction mechanism operating in the material. It has been suggested that at low temperatures the conduction is electronic while at high temperatures it appears to be ionic. As the dopant concentration increases ionic conduction tends to dominate the electronic conduction even at low temperatures. From the current-voltage measurements it has been concluded that the conduction mechanism tends towards Schottky type with increasing dopant concentration.