Search academic texts

Information × Registration Number 0214U001027, 0110U004655 , R & D reports Title Development and progress of method of submicron topography and passport systems of chemical composition, structural perfection, electrophysics parameters and strain distributing in the nanostructures of electronics and optoelectronics. popup.stage_title Head Strelchuk Viktor Vasylyovych, Доктор фізико-математичних наук Registration Date 15-01-2014 Organization Institute of Semiconductor Physics of National Academy of Sciences of Ukrain popup.description2 Apparatus and diagnostic methods of high-resolution scanning confocal Raman and luminescence spectroscopy were developed and improved. Temperature dependence of Raman spectra of silicon nanocrystals in SiOx matrix was investigated. Raman spectra were analyzed considering the combined influence of phonon confinement, anharmonic phonon interaction, and thermal expansion and thermoelastic deformations. Gradual relaxation of thermoelastic tensile strains with temperature was shown. Influence of laser heating effect on the phonon spectrum of Si nanocrystals was investigated. Raman spectra of porous alumina nanocomposite films containing Si nanocrystals were investigated. Two-component behavior of the Raman spectra is explained in the model of confinement of TO phonons in Si nanocrystals with a compressive strain on the interface. Stokes and anti-Stokes Raman spectra were analyzed at varied intensity of exciting radiation and laser heating of Si nanocrystals to temperatures above 1000 K is shown. Two-dimensional graphene layers on the surface of a-SiC/metal Ni structure obtained by thermal annealing in a vacuum were studied. Unusual broadening of 2D band was shown to be due to spatial inhomogeneity of graphene layers within the probed area - graphene layer consists of fragments of two- and multilayered graphenes. Obtained high-frequency shift of 2D-band in the micro-Raman spectra is due to the strain-induced change in the slope of the electronic bands in the vicinity of the point K of the graphene Brillouin zone. Graphene layers formed on the conductive and semi-insulating substrates 6H-SiC were investigated. It is shown that increase in temperature of thermal annealing leads to nonmonotonic changes in the degree of structural defects and cluster sizes of graphene. With temperature increase up to 1350 ° C, the degree of structural perfection of the graphene layers is improved, and at higher temperatures T> 1400 ° C is decreased. The effects of heating of AlGaN/GaN HEMT-structures at applied electric fields were studied. Experimental dependence of temperature in submicron regions of HEMT-structure on the applied voltage was obtained. Differences in temperature values obtained by different methods are due to the effect of local self-heating in nanoregions of conducting channel with two-dimensional electron gas. Product Description popup.authors Авраменко Катерина Андріївна Бойко Микола Іванович Губанов Віктор Олександрович Коломис Олександр Федорович Ніколенко Андрій Сергійович Насєка Віктор Миколайович Насєка Юрій Миколайович Романюк Артем Сергійович Стубров Юрій Юрійович popup.nrat_date 2020-04-02 Close