Electrical Behavior of Pure and Cu Doped Diamondlike Carbon Prepared by Pulsed Laser Deposition

Abstract

ABSTRACTWe have prepared pure diamondlike carbon films and Cu doped diamondlike carbon films through pulsed laser deposition. The Cu concentration does not exceed 3.0 atomic percent. Electrical conduction studies were carried out on the films to understand the electrical transport mechanism. It was found that both pure DLC and Cu doped DLC are of p-type conduction. Incorporation of Cu into the DLC films decreases the resistivity significantly. Transmission electron microscopy and radial distribution function analyses showed that the DLC films are typical tetrahedral amorphous carbon. The conductivity of Cu doped DLC films exhibited T1/2 temperature dependence, rather than the T1/4 dependence (Mott-Davis law). This dependence was observed within a wide temperature range (from below liquid nitrogen temperature to near room temperature). The T1/2 dependence was explained on the basis of the Efros-Shklovskii model which considers the long range Coulomb interaction between localized states