Influence of iodine on the electrical properties of nickel phthalocyanines thin film devices

Abstract

The electrical properties of pure Nickel Phthalocyanine (Ni Pc) thin films and iodine doped Ni Pc thin films with Gold and Aluminium electrode sandwiched devices have been investigated. The electrical properties and the various electrical parameters of the pure and iodine-doped films have been estimated and compared from the analysis of the current density characteristics. From our study we find that the iodine doping enhanced the electrical conductivity compared to pure Nickel Phthalocyanine and the conduction mechanism is much improved with the iodine doping. Interestingly these films after iodine doping showed remarkably increased electrical conductivity nearly ten times that of pure Phthalocyanine. This may be accounted for by the decrease in the metal-metal bond distance. At low voltages the film shows an ohmic conduction whereas at higher voltage levels the conduction is dominated by space charged limited conduction. Further the reverse conduction mechanisms have also been investigated for this sandwiched device. From the current limitations in the reverse condition a strong rectifying behaviour is evident.