THE POSITION OF THE FUNDAMENTAL ABSORPTION-EDGE AND ACTIVATION-ENERGIES FOR THERMALLY ACTIVATED CONDUCTIVITY IN AMORPHOUS-CARBON LAYERS

The electrical de conductivity of amorphous carbon layers with a hydro gen content between 3 and 25 at % was investigated in the temperature range between 80 and 350 K. Additionally, optical measurements in the photon energy range between 0.05 and 3.0 eV as well as EPR measurement s at two temperatures had been carried out. The conductivity values of all types of layers are discussed in terms of a thermally activated h opping process. In this sense all layers behave like semiconductors. F or interpreting these conductivity data different energy band models h ave been applied.