Band tail hopping conduction mechanism in highly conductive amorphous carbon nitride thin films

Nitrogenated amorphous carbon (a-C:N) films have been synthesized by radio frequency (rf) magnetron sputtering at various substrate temperatures and rf discharge powers. The temperature dependence of the electrical conductivity has been measured in order to identify the dominant conduction mechanism. The conductivity was found to increase over ten orders of magnitude with increasing growth temperature and discharge power. In the ohmic regime, the conductivity of the investigated a-C:N films is likely dominated by hopping conduction, in good agreement with a model for hopping in localized bandtail states, rather than by extended states band conduction. (C) 2004 American Institute of Physics.