Completed studies at the University of Lviv (Ukraine) in 1978 - specialty in physics in particular, semiconductor physics. After graduating, i started working at the Institute materials - Karat in Lviv, as an engineer. From 1979, i worked on Pedagogical University of Drohobych in the following positions: lecturer, docent and professor. Since 2002, I have been working at the Institute of Biotechnology of the University of Rzeszow (Poland). Since 2006, I have been working at the Faculty of Mathematics and Natural Sciences University of Rzeszow (Poland) at an associate professor.
Semiconductor Physics
Intensive irradiation as a fast and local heating treatment is the most effective hardware treatment alternative to traditional thermal procedures, especially for nanostructured materials. Methods of using radiation cover a wide range of wavelengths (from ultraviolet to infrared) and powers, which allows you to quickly change the morphology of materials and causes a wide range of phenomena, such as standard heating and compaction of the structure. By using the specific absorption coefficient of the material, it is possible to concentrate the radiation and the subsequent heating in a very narrow region of the set of different layers, thus limiting the heat flow without damaging the substrate. This is especially important for those devices that are directly manufactured on polymer substrates for the implementation of high-performance flexible electronics.
Zinc oxide (ZnO) films were grown on a quartz substrate by laser sputtering at a temperature of 200°C. After growing, the films were exposed to intense pulses of 365nm light from a 12W LED. It was established that irradiation of ZnO films with wavelengths with energy exceeding the band gap causes a decrease in n-type conductivity, which persists for a long time. At fluxes of 1W/cm2, the electrical conductivity of the film decreased by two orders of magnitude and a high apparent transparency was formed. The decrease in conductivity is explained by the decrease in the number of oxygen vacancies and the further promotion of free carriers from the conduction zone. The effects were most pronounced for films processed in an oxygen environment. This is due to the diffusion of oxygen into the film, thereby healing the oxygen vacancies formed during film growth [1]. The film is not damaged under these conditions, the process gives reproducible results after successive cycles.
All radiation-treated films retained their dielectric properties during long-term storage at room temperature. Analysis of the measured photoelectric parameters, in particular photosensitivity at a wavelength of 260nm, made it possible to evaluate the structural and optical properties, since the films became less conductive (reduction of dark current and, accordingly, low-frequency noise 1/f type) and more optically transparent. The results of this study are important for the further development of transparent conducting oxides and provide evidence for the role of free carriers as consequences of point defects in wide bandgap metal oxide films.