Фізика
Постійний URI для цього зібранняhttps://repositary.knuba.edu.ua/handle/987654321/1446
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3 результатів
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Документ Wannier-Stark effect and electron-phonon interaction in macroporous silicon structures with Si02 nanocoatings.(2014) Karachevtseva, L.; Sapelnikova (Kolesnyk), O.; Lytvynenko, O.; Stronska, O.; Goltviansky, Yu.We investigated the contribution ofelectron-phonon interaction to the broadening parameter T of the Wannier-Stark ladder levels in oxidized macroporous silicon structures with different concentration ofSi-O-Si states (TO and LO phonons). The obtained value of the Wannier-Stark ladder parameter ris much less than the djacent level energy evaluated from giant oscillations of resonance electron scattering on the surface states. We determined the influence of broaden ing on the oscillation amplitude in IR absorption spectra as interaction of the surface multi-phonon polaritons with scattered electrons. This interaction transforms the resonance electron scattering in samples with low concentration ofSi-O-Si states into ordinary scattering on ionized impurities for samples with high concentration ofSi-O-Si states. The transformation takes place at the scattering lifetime coinciding with the period of electron oscillations in the surface electric field.Документ Light-emitting structures of CdS nanocrystals in oxidized macroporous silicon.(2016) Sapelnikova, О.; Karachevtseva, L.; Kuchmii, S.; Stroyuk, O.; Lytvynenko, O.; Stronska, O.; Bo Wang; Kartel, M.Structured silicon substrates (macroporous silicon) with Si02 nanolayers and CdS nanocrystals were proposed to reduce the flow of electrons and recombination outside the nanoparticle layer. It was found that the,resonance electron scattering in samples with low concentration of Si—0—Si states transforms into ordinary scattering on ionized impurities for samples with high concentration of Si—0—Si states. The maximal intensity of photoluminescence was measured for a structure with maximum strength of the local electric field at the Si—Si02 interface, indicating a significant decrease of non-radiative recombination in CdS nanocoating due to the flow of electrons from the silicon matrix towards the CdS nanocrystal layer. The quantum yield of photoluminescence increases with time due to evaporation of water molecules.Документ Influence of local electric fields on the photoluminescence of CdS nanocrystals on the oxidized macroporous silicon surface(Chemistry, Physics and Technology of Surface., 2015) Sapelnikova, O.; Karachevtseva, L.; Lytvynenko, O.; Stroyuk, O.; Wrang Bo; Kuchmii, S.; Parshyn, K.