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Information × Registration Number 0208U000315, 0107U005781 , R & D reports Title Development of complex methods of optical and magnetic-resonance diagnostics of Si/Ge and III-V opto- and spinelectronic nanostructures formed by the methods of selforganization popup.stage_title Head Valakh Mykhaylo Yakovich, Доктор фізико-математичних наук Registration Date 23-01-2008 Organization Institute of Semiconductor Physics of National Academy of Sciences of Ukrain popup.description2 A method of non-destructive diagnostics of nanostructures is developed, combining a complex of probe-microscopic, optical and EPR spectroscopic investigations, with the exact sequence of the employment of these techniques being dependent on the kind of the objects under study. For uncapped nanoislands arrays their morphology is investigated by atomic force microscopy first. At this, the surface density, size and shape of the nanoislans are established. For nanostructures with a monomodal shape distribution, investigation proceeds with the resonant Raman spectroscopy study and photoluminescence. Taking into account the change of the bandgap of the islands due to the spatial confinement of the carriers and interdiffusion effect, a variation of the excitation laser wavelength is performed in order to achieve the optimal conditions for the resonant enhancement of the Raman scattering. As a result, the Raman signal from as small quantity of the deposited material as several monolayers can be registered. From analyzing the phonon peaks in the Raman spectra allows the values of the in-built strain, chemical composition and degree of strain relaxation in the nanoislands to be derived. The combination of Raman spectroscopy, high-resolution X-ray difractometry and photoluminescence allows determination of all the above mentioned parameters to be determined for the silicon-caped nanoislands as well. For multilayer structures with nanoislands an additional investigation of the Raman scattering on folded acoustical phonons is performed that allows the vertical correlation of the nanoislands in the stack to be estimated as well as the period of the superlattice. In the course of the project realization, the developed by us methods were tested on wide range of the nanostructures and recommendations were worked out for the improvement of the technology of their fabrication. Three different kinds of nanostructures were tested: single layer structures with silicon-germanium nanoislands, formed at various temperature of theelectron-beam epitaxy - from 300 to 750С and nominal thickness of the germanium deposited - from 3 - up to 15 monolayers; multilayered InGaAs/GaAs nanostructures with the number of periods up to 17; matrix-isolated structures with group II-VI quantum dots. Product Description popup.authors popup.nrat_date 2020-04-02 Close