M. Vogel et al., THE POSITION OF THE FUNDAMENTAL ABSORPTION-EDGE AND ACTIVATION-ENERGIES FOR THERMALLY ACTIVATED CONDUCTIVITY IN AMORPHOUS-CARBON LAYERS, Journal of non-crystalline solids, 166, 1993, pp. 1155-1158
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.