Light emission from silicon is a very inefficient process, due to its indirect bandgap. Therefore, the discovery of Canham, that porous silicon is able to emit light much more efficiently, gave rise to intensive research on systems of silicon nanocrystallites. In this work, the possibility to obtain light emitting Si-crystallites by means of thermal evaporation of commercial siliconmonoxid (SiO) is evaluated. With this intention, silicon suboxid layers (SiOx) are produced by thermal evaporation of SiO, in which crystallites of nanometer size form by thermally induced disproportionation. Rutherford Backscattering (RBS), Infraredspectroscopy, high resolution transmission electron microscopy and photoluminescence measurements are carried out on these Suboxide layers. One focus of this work is to study of the disproportionation behavior of the suboxide. A model for the growth of silicon crystallites is developed on the basis of RBS and IR-data as well as the statistical size distribution obtained from HRTEM. An other focus is set on the luminescence properties of the nanocrystallites obtained by annealing the SiOx-layers at high temperature. The observed luminescence properties can be completely explained by the 'quantum-confinement-model'. This interpretation is directly proven by low temperature measurements under resonant excitation. The very low surface roughness of the SiOx-layers opens the possibility to obtain buried layers of silicon nanocrystallies without expensive polishing by wafer bonding, which is discussed in the last chapter.