Amorphous Si_(1-x)Sn_x alloys have been prepared by co-evaporation onto substrates maintained atliquid nitrogen temperature. Their atomic structure is investigated using density measurements,scanning high-energy electron diffraction and Mossbauer spectroscopy. The optical and electricalproperties are reported. Then, a method to hydrogenate the films during the evaporation process isdescribed and applied to the preparation of amorphous semiconductors from pure silicon to pure tin.Finally, multilayers of type Si / Si:H / ... or Si:H / Si:D / ... are studied. The modulation of hydrogen isshown by low-angle neutron scattering and measurements of hydrogen diffusivity are presented. The amorphous structure is investigated using density measurements, scanning high-energy electron diffraction and Mossbauer spectroscopy. The optical and electrical properties are reported. Then , a method to hydrogenate the films during the evaporation process isdescribed and applied to the preparation of amorphous semiconductors from pure silicon to pure tin. Finally, multilayers of type Si / Si: H / ... or Si: H / Si: D / The modulation of hydrogen isshown by low-angle neutron scattering and measurements of hydrogen diffusivity are presented.