http://dspace.nbuv.gov.ua:80/handle/123456789/114450 Mon, 20 Apr 2026 19:01:55 GMT 2026-04-20T19:01:55Z http://dspace.nbuv.gov.ua:80/bitstream/id/340888/ http://dspace.nbuv.gov.ua:80/handle/123456789/114450 http://dspace.nbuv.gov.ua:80/handle/123456789/117671 The influence of temperature on optical properties of merocyanine dye thin films Sieryk, M.M.; Doroshenko, T.P.; Grytsenko, K.P.; Navozenko, O.M.; Tolmachev, O.I.; Slominski, Yu.L.; Schrader, S. Merocyanine dye thin films have been investigated using optical microscopy methods. The films were deposited using the method of thermal evaporation. The influence of substrate type and temperature on optical properties and spatial orientation of molecules in the above films has been studied. The influence of annealing on structural reorientation of molecules in thermally deposited dye films has been determined. Tue, 01 Jan 2013 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/117671 2013-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/117670 Laser heating effect on Raman spectra of Si nanocrystals embedded into SiOx matrix Nikolenko, A.S. Influence of combined size confinement effect and effect of local laser heating on the first-order Raman spectrum of silicon nanocrystals embedded into SiOx matrix has been studied. Increase of the local temperature of Si nanocrystals caused by laser illumination with the power density up to 10 mW/μm² was estimated from the ratio of the Stokes/anti-Stokes peak intensities. Almost linear dependence of nanocrystals local temperature on the power density of exciting radiation with a rate of 63.6 Km² /mW has been found. The phonon line shape at power densities, when no laser heating effect is registered, was shown to be described well within the correlation length model of phonon confinement of Si nanocrystals with the size L = 9.2 nm. Observed phonon softening and broadening with increase of the exciting power density is considered as temperatureinduced vibration anharmonicity with the decay of optical phonons through three and four-phonon processes and corresponding anharmonic constants have been determined. Tue, 01 Jan 2013 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/117670 2013-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/117669 A subharmonic mixer for the 220–325 GHz frequency range Zorenko, A.V.; Kolesnik, N.V.; Kritskaya, T.V.; Kudryk, Ya.Ya.; Marunenko, Yu.V.; Ryzhanovich, L.P. We have made a subharmonic mixer (SHM) for the 220–325 GHz frequency range with conversion losses lower than 30 dB at the intermediate frequency 3 GHz. The subharmonic mixer design was based on a GaAs mixer Schottky barrier diode with beam leads on a quartz 25-μm thick microwave board. The microwave board was placed in a package with a waveguide channel of local oscillator input (cross-sectional area 1.2×2.4 mm) and waveguide channel of signal input (cross-sectional area 0.4×0.8 mm² ). The IF signal goes out through a subminiature A-connector, wave impedance of which is 50 Ohm. Tue, 01 Jan 2013 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/117669 2013-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/117668 Features of piezoresistance in heavily doped n-silicon crystals Gaidar, G.P. It has been shown that in silicon single crystals heavily doped with arsenic the presence of the temperature gradient at the interface of the liquid and solid phases in the process of growing them from a melt does not lead to anisotropy of piezoresistance under the passing current both along the direction of deforming load (J || X || 111) and perpendicularly to it (J ⊥ X || 111). This is considered as an evidence of the dominant influence of randomization in spatial distribution of a dopant due to kT (at T = 1685 K) during the growth of single crystals. Tue, 01 Jan 2013 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/117668 2013-01-01T00:00:00Z