Drogobych State Pedagogical University

Drohobych, Ukraine

Drogobych State Pedagogical University

Drohobych, Ukraine

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Virt I.S.,Drogobych State Pedagogical University | Virt I.S.,University of Rzeszow | Tur Y.,Drogobych State Pedagogical University | Rudyi I.O.,Lviv Polytechnic | And 6 more authors.
Journal of Crystal Growth | Year: 2015

Lead telluride (PbTe) undoped films with various thicknesses (40-1800 nm) were grown by pulsed laser deposition (PLD) on different single crystal substrates (KCl, Si) and at different substrate temperatures (30 °C, 200 °C). Structural and electrical investigations of the so-obtained films have been carried out. The growth conditions leading to the films having different properties that could be controlled in a possibly wide range were identified. The film crystal structure varied from pseudo-amorphous to a highly ordered one. The films exhibited semiconducting behavior except the case of the thinnest, metallic-like layers. Electrical transport properties of the films with different structural quality were affected by changes of the grain boundary-related potential barrier height whereas donor level-related activation energies remained unchanged. © 2015 Elsevier B.V.


Virt I.S.,Drogobych State Pedagogical University | Virt I.S.,University of Rzeszow | Rudyi I.O.,Lviv Polytechnic | Lopatynskyi I.Y.,Lviv Polytechnic | And 4 more authors.
Journal of Electronic Materials | Year: 2016

Three lead chalcogenide films, PbTe, PbSe, and PbS, with a high structural quality were grown by pulsed lased deposition (PLD). The films were grown on single crystal substrates (Si, KCl, Al2O3) and on Si covered with a Si3N4 buffer layer. The Si3N4 layer latter facilitated the lead chalcogenide layer nucleation during the first growth stages and resulted in a more homogeneous surface morphology and a lower surface roughness. The surface geometry (roughness) of the films grown on Si3N4 was studied by means of the power spectral density analysis. Different growth modes, ranging from plasma plume condensation to bulk diffusion, resulting in observed film morphologies were identified. The investigations were complemented by electrical characterization of the chalcogenide films. © 2016 The Author(s)


Virt I.S.,Drogobych State Pedagogical University | Virt I.S.,University of Rzeszow | Shkumbatyuk T.P.,Drogobych State Pedagogical University | Kurilo I.V.,Lvivska Politekhnika National University | And 5 more authors.
Semiconductors | Year: 2010

Bi2Te3 and Sb2Te3 films were obtained by pulsed laser ablation. The films were deposited in vacuum (1 × 10-5 Torr) on single crystal substrates of Al2O3 (0001), BaF2 (111), and fresh cleavages of KCl or NaCl (001) heated to 453-523 K. The films were 10-1500 nm thick. The structures of the bulk material of targets and films were studied by X-ray diffractometry and transmission high-energy electron diffraction, respectively. Electrical properties of the films were measured in the temperature range of 77-300 K. It is shown that the films possess semiconductor properties. Several activation portions are observed in the temperature dependences of resistivity; the energies of activation portions depend on the film thickness and crystallite size. © 2010 Pleiades Publishing, Ltd.


Sagan P.,University of Rzeszow | Popovych V.,Drogobych State Pedagogical University | Bester M.,University of Rzeszow | Kuzma M.,University of Rzeszow
Solid State Phenomena | Year: 2013

In this paper we have obtained CdCrTe thin layers by PLD method using the YAG:Nd3+ laser with pulse duration of 250μs. Pre-synthesized polycrystalline ingot of CdCrTe solid solution with 50% wt. of Cr in the initial charge has been taken as a target. The layers were deposited on KCl substrate. The target and films were analyzed using X-ray diffraction, TEM microscope and THEED electron diffraction. The morphology of the layers is homogenous. However, we have detected several different crystallographic phases: cubic CdTe, hexagonal Cr and hexagonal Te. From the measurements of lattice constant of the layer, their composition was determined to be x=0,14. © (2013) Trans Tech Publications, Switzerland.


Virt I.,Lviv Polytechnic | Virt I.,Drogobych State Pedagogical University | Virt I.,University of Rzeszow | Rudyi I.,Lviv Polytechnic | And 7 more authors.
Solid State Phenomena | Year: 2013

Structural and magnetic properties of ceramics Zn1-xCoxO and Zn1-xCrxO are studied. Average sizes of grains are determined by scanning electron microscopy. The magnetic field dependences of magnetic susceptibility are investigated by Faraday method. The relevant theoretical models are chosen. © (2013) Trans Tech Publications, Switzerland.


Virt I.S.,Drogobych State Pedagogical University | Virt I.S.,Lviv Polytechnic | Hadzaman I.V.,Drogobych State Pedagogical University | Bilyk I.S.,Drogobych State Pedagogical University | And 4 more authors.
Acta Physica Polonica A | Year: 2010

The results of experimental investigation of structural and physical properties of ZnO and ZnMnO films are presented in this work. The films of ZnO and Zn1-xMnxO of different thickness were obtained on Al2O3, glass, and KCl substrates in vacuum of 1 × 10-5 Torr by the pulsed laser deposition method. The samples were obtained under the substrate temperature 300-473 K. A thickness of films was in the range of 0.5-1 μm depending on the number of laser pulses. The structure of target bulk materials was investigated by X-ray diffraction method. A structure of laser deposited films was investigated by the transmission high-energy electron diffraction method. Electric resistivity was measured in the temperature range 77-450 K. The presence of two activation energies in the temperature range 300-330 K and 330-450 K is followed from the analysis of the films electrical resistivity. These activation energies correspond to two deep donor's energy levels. The shallow donor's level is connected with manganese presence. Optical transmission of ZnO and ZnMnO films deposited at various temperatures were investigated.


Virt I.S.,Drogobych State Pedagogical University | Virt I.S.,University of Rzeszow | Rudyj I.O.,Lviv Polytechnic | Kurilo I.V.,Lviv Polytechnic | And 5 more authors.
Semiconductors | Year: 2013

The properties of Sb2S3 and Sb2Se3 thin films of variable thickness deposited onto Al2O3, Si, and KCl substrates are investigated by the method of pulsed laser ablation. The samples are obtained at a substrate temperature of 180°C in a vacuum chamber with a residual pressure of 10-5 Torr. The thickness of the films amounted to 40-1500 nm. The structure of the bulk material of the targets and films is investigated by the methods of X-ray diffraction and transmission high-energy electron diffraction, respectively. The electrical properties of the films are investigated in the temperature range of 253-310 K. It is shown that the films have semiconductor properties. The structural features of the films determine their optical parameters. © 2013 Pleiades Publishing, Ltd.


Popovych V.,Drogobych State Pedagogical University | Bester M.,University of Rzeszow | Stefaniuk I.,University of Rzeszow | Kuzma M.,University of Rzeszow
Nukleonika | Year: 2015

The difficulty in determining the electron paramagnetic resonance (EPR) line parameters of ferromagnetic semiconductors has been addressed. For these materials, the resonance line is very broad and lies at low resonance field, so that only a part of the line can be detected experimentally. Moreover, the line is of asymmetric (Dysonian) shape as described by the line shape parameter α. We have compared values of line parameters derived by computer fitting of the whole experimental EPR line to the Dyson function (or modified Dyson function) with the values obtained by applying this procedure to the left and the right half of the line.

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