Electrical conduction properties of Co-doped ZnO nanocrystalline thin films

Abstract

The temperature dependent conductivity behavior of 15% Co and 25% Co-doped ZnO nanocrystalline thin films prepared by spin-coating method was examined. It was found that the conductivity shows a change when the Co concentration varies from 15 to 25%. The observed increase of conductivity with increasing Co concentration was interpreted through the grain boundary conduction model. The temperature dependent conductivity of the films was analyzed in term of formulas in consistence with grain boundary conduction model. With rising temperature for 25% Co doped ZnO, a transition from the region in which crystallites are only partially depleted to the region in which the crystallites are entirely depleted was observed around 375 K. Some improtant electrical parameters were determined for the films.