http://dspace.nbuv.gov.ua:80/handle/123456789/114578 2026-04-12T19:58:37Z http://dspace.nbuv.gov.ua:80/handle/123456789/118696 Matrix model of inhomogeneous medium with circular birefringence in single scattering case Savenkov, S.N.; Oberemok, Ye.A.; Yakubchak, V.V.; Barchuk, О.I. The paper is devoted to the analysis of light scattering by inhomogeneous circular birefringent media in a single scattering case. The object under investigation is a circular birefringent crystalline slab with surface inhomogeneity. For the analysis, we derive the Mueller matrix model for this media and use Cloude’s coherency matrix method. Sample calculations are given for quartz SiO₂ and paratellurite TeO₂ . 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/118695 Determination of refractive index dispersion and thickness of thin antireflection films TiO₂ and Si₃N₄ on surfaces of silicon photoelectric converters Donets, V.V.; Melnichenko, L.Y.; Shaykevich, I.A.; Lomakina, O.V. Offered in this work is the method to determine the thickness and refractive index dispersion of thin antireflection films on absorbing substrates by using a spectral dependence of reflectivity at normal light incidence. The method has been applied to determine the above characteristics of thin antireflection films TiO₂ and Si₃N₄ on surfaces of silicon photoelectric converters. The films were prepared by chemical sedimentation. The obtained experimental data have been treated using a computer program to deduce dispersion curves and thickness values. The results have been interpreted. 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/118694 Data acquisition, parameter extraction and characterization of active components using integrated instrumentation system Bourdoucen, H.; Zitouni, A. A data acquisition, parameter extraction and characterization system for electronic active components is presented in this paper. High sensitivity measuring equipments were used for data acquisition and effective extraction models based on optimization techniques developed to obtain the parameters of p-n junction diodes, Schottky diodes, field effect transistors and bipolar junction transistors. The performance of the developed extraction techniques are apparent via comparing experimental data with Spice simulated data using the model parameter that is graphically extracted and also those extracted using optimization techniques. The performance of the developed extraction techniques has been demonstrated by comparing the experimental characteristics with Spice simulated curves using default parameters and model parameters extracted using graphical and optimization techniques. The relative excursions of the simulated I-V characteristics of most investigated devices were less than 2.5 % with respect to the experimental curves, which shows the accuracy and effectiveness of the developed system. A number of software routines have also been implemented under Matlab environment to extract the Spice model parameters for different electronic devices. 2009-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/118693 Hydrogenic impurity in a bilayer spherical quantum dot Boichuk, V.I.; Bilynskyi, I.V.; Leshko, R.Ya. In the work, on the basis of the exact solution of the Poisson equation for a bilayer quantum dot with a positively charged donor ion in its centre, determined is the potential energy of interaction of this impurity ion with electron, taking into account different known values of Si and SiO₂ dielectric permittivities. Using the found potential energy, the Schrödinger equation for the hydrogenic impurity in this system is solved exactly. The influence of external and internal radii on the electron spectrum is investigated. Described is the dependence of a squared matrix element for the dipole moment of interlevel transitions on the external and internal radii of the nanoheterosystem 2009-01-01T00:00:00Z