Papers by Author: T.V. Torchynska

Abstract: The paper presents the results of SiC nanocrystal characterization using photoluminescence spectroscopy technique. Earlier it was shown that original SiC wafers and porous SiC (PSiC) layers have been characterized by 6H-SiC crystal type with inclusions of 4H-, 15R- and 2H- SiC polytypes. The study of photoluminescence in PSiC layers with different nanocrystal (NC) sizes reveals the intensity stimulation for exciton-related PL bands in NCs of different SiC polytypes. The intensity enhancement for exciton-related PL bands is attributed to the exciton recombination rate increasing due to the realization of exciton weak confinement and exciton-polariton coupling in SiC NCs. The numerical simulation has been done for the dependence of exciton recombination rate versus SiC NC sizes at the assumption of exciton-polariton coupling model.

Abstract: This paper presents the results of PL spectrum studies for Si nano-crystallites embedded in amorphous silicon matrix. Investigated layers were deposited by the hot-wire CVD method on glass substrates at the wafer temperature 300°C and different filament temperatures from the range 1650-1950°C. It was shown that variation of temperatures of filament (hot-wire) allows to produce the films with desirable parameters. Using of X-ray diffraction and photoluminescence methods the correlation between some photoluminescence bands and the sizes of Si nano-crystallites as well as the amorphous phase volume was shown. The nature of light emission is discussed.