A NEW APPROACH IN THE OPTICAL CHARACTERIZATION OF AMORPHOUS HYDROGENATED SILICON CARBON ALLOYS

An expression for the imaginary part of the dielectric function for amorphous silicon-carbon alloys is assumed following previous treatments already adopted for other amorphous semiconductors like silicon, germanium, gallium arsenide, and silicon nitride. The real part of the complex dielectric function is obtained using Kramers-Kronig analysis. The model requires the knowledge of four parameters. Suitable values of these parameters can be obtained by fitting the optical spectra of the samples. The results show that the parameters allow a deep physical insight and are strictly related to the composition of the films and to the preparation methods.