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Information × Registration Number 0223U000385, 0122U000605 , R & D reports Title Physical and chemical aspects of formation of semiconductor chalcogenide nanocrystals of various morphology in Bi(Sn)–As–S and Ag–In(Ga)–S systems and modification of their characteristics by variation of technological parameters of fabrication and ionizing radiation popup.stage_title Head Azhniuk Yurii M., Доктор фізико-математичних наук Registration Date 06-01-2023 Organization Institute of Electronic Physics of the National Academy of Sciences of Ukraine popup.description2 Deformation of an As2S3 film surface due to below-bandgap light illumination is observed by atomic force microscopy revealing a giant photoexpansion of the film. Above-bandgap illumination results in the giant photoexpansion and directed mass transport leading to the formation of a dip (due to the gradient optical force) and a protrusion along the optical beam propagation (due to the scattering force) on the film surface. Dynamics of stopping effect and behaviour of refractive index in fresh amorphous AsxS100-x (15≤x<30) films under above-bandgap illumination is studied by waveguide technique. Observed features of kinetics of photoinduced refractive index variation and temporal characteristics of the stopping effect are related to increasing strength of interatomic bonds and decreasing polarizability. The compositional interval of existence of the (As1–xBix)2S3 glassy phase is extended by obtaining glasses with 0 x0.2. Their amorphous character and absence of crystalline inclusions is confirmed by Raman spectroscopy. Photochemical processes on the (As1–xBix)2S3 surface are revealed, caused by photoinduced interaction of sulphur with adsorbed atoms of nitrogen and carbon. Synthesis of (As2S3)х(Bi2S3)1-х solid solutions with х from 0.04 to 0.14 and their subsequent annealing at 220–310 С results in bulk composite materials with Bi2S3 nanocrystals what is confirmed by X-ray diffraction data. Optical absorption edge shifts towards lower energies with introduction of Bi2S3 in glass and thermal treatment. Glutathione-capped AgInS2 and Ag–Ga–S nanocrystals are obtained by colloidal synthesis in aqueous solutions at mild conditions. Average nanocrystal size (about 2 nm) is determined from X-ray diffaction and atomic force microscopy. Nanocrystal size-selected fractions of colloidal solutions are characterized by Urbach absorption edge and intense broadband photoluminescence. Ag–Ga–S nanocrystals are shown to possess metastable crystal structure and indirect band gap. Product Description popup.authors Byrov Mykola M. Voynarovych Ivan Mykolajovych Hasynets Stepan M Gomonnai Olexandr V. Kryshenyk Volodymyr M Lopushanska Bohdana V. Lopushansky Vasyl Volodymyrovych loya Vasyl Yu. Maslyuk Volodymyr Trokhymovych Solomon Andrij M Chychura Ivan I popup.nrat_date 2023-01-06 Close