Electronic properties of plasma-deposited films prepared from tetramethylsilane

Investigations were carried out on an optical absorption, reflectance, photoluminescence, photoconductivity and d.c. conductivity of hydrogenated amorphous Si-C films prepared by plasma deposition from tetramethylsilane at various substrate temperatures Ts in the range 400-670K. The results have been interpreted in terms of the electronic structure of the thin. It was found that the dielectric character of the electronic structure is generally maintained regardless of Ts although some changes in parameters of the electronic structure, such as transport gap, optical gap and activation energy of d.c. conductivity were observed with increasing Ts. These changes are attributed to shifts in the valence and conduction states into the transport gap.