Amorphous silicon-carbon films prepared by reactive evaporation

An ion-beam-assisted deposition (IBAD) technique, based on reactive evaporation using hydrogen/ methane gas mixture, has been used for the preparation of a-Si1-x Cx : H films. Measurements are reported on the composition, optical gap, infra-red vibrational absorption bands and on the electrical dark-conductivity temperature dependence to verify the reliability of this deposition method. On increasing the compositional parameter x up to 0.35, the IR results show an increasing hydrogenation and the presence of Si-CH3 units in addition to the ones with the carbon fully coordinated with the silicon, while the optical-gap and the dark-conductivity activation energies reached the values of 2.44 eV and 0.77 eV, respectively.