The activity is mainly focused on the on the design, fabrication and characterization of silicon photonic and optoelectronic devices able to modulate and generate light. A first activity concerns optical modulation: it is focused on the design, fabrication and characterization of electro-optic modulators with an amorphous hydrogenated silicon (a-Si:H) PIN structure integrated into a waveguiding Mach-Zender interferometer. Modulation mechanism is based on the plasma-optic dispersion effect, inducing a difference of optical length between the two arms of the interferometer. Electro-thermal-optical FEA simulations of the devices are also carried out in order to obtain an optimum design. A second activity concerns photoemission: with the aim of demonstrating a convenient path to monolithic integration of optical and electronic devices within the mainstream Si technology, (i) photo- and electro-luminescence of erbium/silicon and graphene-like/silicon hybrid junctions, and (ii) stimulated Raman scattering (SRS) in Si nanocrystals and Si nanocomposite are investigated as an interesting alternative approach for optical amplification and light generation. All devices are fabricated by processes compatible with the well-known and mature silicon technology. Applications are in the field of both ICT and optical interconnects.