In the field of nanostructured materials, our research was focussed on the synthesis and applications of silicon based nanostructured films. In particular, we studied nanocrystalline Si and Sic thin films, having film thicknesses in the nanometer range and including nanometric grains, and compositionally modulated nanometric multilayers of a-SizN4: H/a-Si, Ni-x: H. The Plasma Enhanced Chemical Vapour