Yukhymchuk V. Optical properties of silicon, germanium and carbon nanostructures, obtained by ion implantation

The thesis is devoted to the experimental studies of optical characteristics of silicon and germanium quantum dots as well as carbon clusters in SiO2-matrix and investigation of buried layers in silicon, formed by ion implantation and subsequent high-temperature annealing. The emission of Si/SiO2:Si+ samples in the range of 620 nm and 740 nm is shown to be of different nature. The first photoluminescent band results from defects. The second band is related to the formation of silicon quantum dots in SiO2-matrix. The size of Si and Ge nanocrystallites in SiO2 is evaluated by Raman spectroscopic technique. A correlation between structural features of carbon clusters in the SiO2-matrix and the photoluminescence intensity of C+ implanted Si/SiO2 structures is obtained. As follows from the optical methods the difference in the ion radii of oxygen and carbon from that of silicon can be used at double implantation of O+ and C+ ions for efficient formation of SiO2 and SiC buried layers in silicon. The values a nd distribution of mechanical strains in Si layers, arising under ion-beam synthesis of buried SixGe1-x layers are obtained.