Scientific Program

Keynote Talks

Abstract

Persistent phosphor materials at the transparent windows of bio-tissues are expected for in vivo imaging without excitation source, which produces various noises such as auto-fluorescence. The ZnGa2O4:Cr3+ spinel phosphor[1] is a successful example of persistent luminescence at 700nm, corresponding to the 1st bio-imaging window. Because of lower scattering loss and recently advanced availability of InGaAs photo-detectors, near-infrared (NIR) fluorescence probes have been widely developed with luminescence of Nd3+:1.06-m and Er3+:1.55-m, where conventional photoluminescence (PL) is working. In contrast to Cr3+, Mn2+, Ce3+, Pr3+, and Eu2+ ions, the photo-ionization mechanism by UV illumination for the electron charging seems unfeasible in the Nd3+ and Er3+ ions, which take very stable trivalent state. We have developed garnet-based persistent phosphors in which Nd3+[2] or Er3+[3] ions show very efficient and long NIR persistent luminescence. Photon emission rate and duration of these materials are only slightly lower and shorter than the visible persistent phosphors of Ce3+-doped garnets we developed in 2014[4], the performance of which is almost comparable to the SrAl2O4: Eu2+, Dy3+ phosphor. These phosphors can be applied to in vivo imaging in the 2nd and 3rd bio-imaging windows of high transparency and sensitivity of InGaAs detectors.

Biography

Setsuhisa Tanabe received his PhD from Kyoto University, Japan. He is now a full Professor of Kyoto University. He has published more than 200 papers in reputed journals, 25 book chapters and 37 review papers on rare-earth doped luminescent materials for up conversion, fiber amplifier for optical telecommunication and LED phosphors. He has served as a plenary, keynote or invited speaker at more than 100 international conferences. He was the chair of Technical Committee of Optoelectronic Glasses (TC20) of International Commission on Glass (ICG) and now a member of Steering Committee of ICG since 2013. He has been serving as a vice Editor of Journal of Luminescence since 2015.

Speaker
Setsuhisa Tanabe / Professor, Kyoto University, Japan

Abstract

Transparent yttria-stabilized zirconia (YSZ) ceramic samples have been manufactured by the spark plasma sintering (SPS) at various conditions. The optical and corresponding mechanical properties of the sintered samples were studied. A parameter for optimizing SPS processing has been suggested which characterizes optical transparency versus sample thickness. The dynamic evolution of the swelling areas over time after local indentation of transparent YSZ ceramics was shown. The appearance of spalls from the swelling areas depends on the degree of internal mechanical stresses in the given region of the sample and is explained by the relaxation of stresses accumulated on deformation during static indentation [1]. Translucent YSZ ceramic samples have been manufactured by the dry powder uniaxial pressing at powerful ultrasound assistance (PUA) and following free sintering. The effect of the powder compaction pressure and sintering temperature on the density and microstructure of the sintered ceramics was investigated. Translucent ceramic samples having density up to 98% were obtained by the method of static uniaxial pressing at powerful ultrasound assistance (PUA) and with subsequent sintering. The effect of PUA on the elastoplastic and optical properties of sintered translucent YSZ ceramic samples was investigated.

Biography

Professor Oleg Khasanov is head of Department Nanomaterials and Nanotechnologies and director of Nano-Centre of National Research Tomsk Polytechnic University, Russia. He is Dr.Sc. (Engineering, Materials Science of Ceramics) since 2004 and Ph.D. (Physical-mathematical Sciences) since 1986. His researches include study and development of methods of uniform packing of nanoscaled and micrometric dry powders into required shapes with a control of friction forces. The developed methods have been applied for manufacturing a lot of parts from oxide and non-oxide functional nanostructured ceramics and composites including transparent ceramics. Several developed technologies have been transferred in the industry. Oleg Khasanov team deals with RD on luminescent transparent ceramics. He was visiting Professor at University of Ulsan (Republic of Korea, 1998), University Joseph Fourier (Grenoble, France, 2014), Chongqing University of Arts and Science (China, 2016). He has published more than 150 papers in international journals and proceedings; his inventions were patented in Russia, USA, Germany, France, Italy (Europatent), Republic of Korea, India, etc. He delivered invited talks at many regular international conferences/congress on ceramics (ECerS, ICC, SPS Forum, JSPMIC).

Speaker
Oleg Khasanov / Professor, National Research Tomsk Polytechnic University, Russia.

Sessions:

Scientific Sessions

Abstract

Luminescent semiconductor nanocrystals (NCs) have gained increasing attention in the past decade due to their unique optical, electronic and magnetic properties that are not available in either isolated molecules or bulk solids. Then NCs are potential candidates for various technical applications such as light-emitting diodes and lasers and biological fields. In this paper we consider an easy way of obtaining a doped CdTe NCs at room temperature. CdTe nanocrystals were synthesized in aqueous medium by the method colloidal synthesis in a semi-periodic reactor. For stabilization of CdTe NCs surface during the synthesis tioglycol acid S(CH2CO2H)2 (99 %) has been used. To optimize CdTe NC formation parameters, we measured the photoluminescence spectra of colloidal solutions of CdTe NCs and determined the particle size by calculational techniques and experimentally, using photon correlation spectroscopy. The alloying of CdTe NCs by ions of the f-group is an interesting and promising task, in particular because their intraatomic transitions lie in the visible and near infrared regions of the spectrum. For example, the maximum of the luminescence of the erbium is observed at a wavelength of 1550 nm, which corresponds to the second window of transparency in fiber optic transmission systems. However, these transitions are prohibited by the rules of selection and the intensity of these lines is very small. Therefore, the implantation of an ion into a nanocrystal characterized by strong absorbing power, and provided by an effective energy transfer occurs, will significantly increase the required luminescence. From the side of synthesis, the introduction of several impurity atoms in a NC containing only a few hundred atoms can lead to their expulsion to the surface or deteriorate the crystalline structure. Actually this is the creation of highly doped NCs in conditions of strong confinement. Electronic and optical properties in such conditions are not completely studied yet.

Biography

Dmytro Korbutyak received his PhD in the year 1976. He is now a full Professor of V.Lashkaryov Institute of Semiconductor Physics National Academy of Sciences of Ukraine Head of semiconductor nanophotonics department. He has served as a plenary, keynote or invited speaker at most of the reputed international conferences. He has two monographs published (1987, 2000). Laureate of the State Prize of Ukraine in the field of science and technology (1997) Prize of the Academies of Sciences of Ukraine, Belarus and Moldova (2013). He was awarded the title of the professor in 1992. He has published more than 200 articles in well-known scientific journals. Now he is continuing to work as a member of the editorial board of two authoritative journals.

Speaker
Dmytro Korbutyak / Professor, National Academy of Sciences, Ukraine.

Abstract

The work is a review of low-temperature RF plasma treatment (RFPT) of shallow layers of n- and p-type Ge and Si disordered by ion implantation of different kinds of ions (B+, P+, As+, BF2+) and proposing of models elucidating of strong ordering of defect and amorphous thin layers. The RFPT (13.6 MHz) was performed in forming gas, N2 and H2 gases with additional heating (up to 250°C). Thermal annealing (TA) and RTA of the implanted samples in nitrogen atmosphere were performed for comparison. Amorphous phase ordering (in case of Si) and recrystallization (in case of Ge) of the thin subsurface layers and activation of implanted dopant were analyzed by Raman scattering spectroscopy (RSS); surface morphology – by AFM; distributions of implanted and activated dopant - by SIMS and ECV; electrical properties of the thin layer - by CV and four probes methods and thermally activated current spectroscopy. The RSS shown that amorphous phase in the thin Ge layer was recrystallized by TA at considerably higher temperature than in case of RFPT, while in case of thin Si layer a strong ordering of amorphous phase was observed. Direct experiments with RFPT of front and back sides of the samples demonstrated manifestation of nonthermal processes enhanced of RF plasma treatment. The nature of enhanced defect layer ordering, recrystallization of the amorphous implanted Ge layers and implanted dopant activation is discussed.

Biography

Prof. Alexei Nazarov has completed his habilitation on DrSci in Physics and Mathematics from Institute of Semiconductor Physics NASU, Kyiv, Ukraine. He is the head of department of Functional Materials and Nanostructure and professor of Physical and Mathematical Faculty of National Technical University "Igor Sikorsky KPI". He has published more than 250 papers in reputed journals and has been serving as special editor and author of 11 books and journals.

Speaker
Alexei Nikolaevich Nazarov / Professor, University of Ukraine, Ukraine.

Abstract

The error of positioning in the angular direction caused by the limited accuracy of the angular encoder is rather specific and typical only for laser pattern generators containing a rotation unit. The error of this encoder is particularly important for formation of topology of angle measuring structures, such as angular rasters, limbs, scales, or multibit code disks, and for synthesis of topology of arbitrarily shaped diffractive optical elements, especially at large radii. The method of improvement the accuracy of laser pattern generator with circular scanning is proposed. The result is achieved by using a new type angular encoder in it. It’s using allows to measurements of the turning angle and current radial deflections of the angular coordinate laser pattern generator rotor axis simultaneously. For that two measuring patterns – radial raster for measuring angular displacement and ring for measuring linear shift raster in a tangential direction are formed on a single glass basis for one technological process.

Biography

Kiryanov Alexey, Ph.D. (Technical Sciences), head of laboratory Integrated Informational Control System of the Institute of Automation and Electrometry, Siberian Branch of the Russian Academy of Sciences (IA&E, SB RAS). Research interests – laser pattern generators, precision mechatronic systems, optoelectronic angular encoder. Author and co-author more than 50 scientific articles, patents for inventions.

Speaker
Alexey V. Kiryanov / Head of laboratory, Institute of Automation and Electrometry,Russia.

Abstract

Electric and magnetic optical fields carry the same amount of energy. Nevertheless, the efficiency with which matter interacts with electric optical fields is commonly accepted to be at least 4 orders of magnitude higher than with magnetic optical fields. Here we experimentally demonstrate that properly designed photonic nanostructures (figure 1) can selectively manipulate the magnetic versus electric emission of luminescent nanocrystals. In particular, an enhancement of magnetic emission from trivalent europium-doped nanoparticles can only by observed in the vicinity of nanostructures featuring a magnetic field enhancement. Moreover, by controlling the spatial coupling between emitter and nanoresonator using near-field microscopy, local distributions of both magnetic and electric radiative local densities of states can be readily recorded with nanoscale precision (figure 2), revealing the modification of the quantum environment induced by the presence of the nanostructures. This manipulation and enhancement of magnetic light and matter interactions is a turning point in nanophotonics, opening up new possibilities for the research fields of opto-electronics, chiral optics, nonlinear & nano-optics, spintronics and metamaterials, amongst others.

Biography

Mathieu Mivelle became a permanent researcher in January 2016 after being recruited by the CNRS (French National Research Institution). By designing and applying photonic nanoantennas to enhance the electromagnetic near-field, his research focuses on studying the interactions between light and matter at the nanoscale, and in particular the interactions due to the magnetic part of light. Previously, Mathieu Mivelle obtained his PhD in Physics, working on near field optics at the FEMTO-ST institute in Besancon, and worked as a Post-doctoral researcher in the ICFO institute in Barcelona and the Langevin Institute in Paris on the coupling between single emitters and photonic antennas.

Speaker
Mathieu mivelle / Scientist, Pierre and Marie Curie University, France.

Abstract

Coal is a natural nanostructured material. Physical-Chemical properties of coal depend on from the stage of metamorphism. The stage of metamorphism is estimated by a variety amount volatile substance (Vdaf). The pyrolysis process characterised structural transformation of coal under temperature and pressure where physical-chemical properties were changed including paramagnetic properties. In this paper using by SEM, EDX and EPR methods were investigated a morphology of surface, element analysis and paramagnetic properties of a gas type coal (Vdaf = 39-46 at.%) after vacuum annealing at T = 700 0C. SEM analysis data showed, that the surface of coal consists of a large amount pores which were created during vacuum annealing. The carbon content of coal was increased up 95 at. % after the vacuum annealing. EPR spectra consist of two resonance lines L1 and L2 of Lorentz shape after vacuum annealing. At the first time, was observed an untypical behaviour of paramagnetic centres of coal with an interaction of molecular oxygen after vacuum annealing. The strong broadening of the L1 line (Hpp250 G) related to with influence the huge amount oxygen on the structure of coal after vacuum annealing. During of the time, the width and concentration of paramagnetic centres of the L1 line were slowly decreasing after vacuum annealing. This untypical behaviour was related to formation weakly chemical bonds of the carboxyl group. Also was registered increasing intensity of L2 line, which related to the structure relaxation of a chemical bond and diffusion free radicals. The width of an L2 line was not changed. Finally,the same adsorption mechanism of pyrolyzed coal was observed with contacting the vapour of water.

Biography

Serhii Krasnovyd has completed master of Science in Physics at the age of 23 years in the National Technical University of Ukraine “Kyiv Polytechnic Institute” In the age 26 was finished PhD studies in the Institute of Semiconductor Physics of Ukraine. At now time Serhii Krasnovyd is junior researcher in the Institute of Semiconductor Physics of Ukraine. He has published 6 papers in reputed journals. Serhii Krasnovyd took part in the collaboration projects “Marie Curie Actions - International Research Staff Exchange Scheme” Aston University, Birmingham, UK. Serhii Krasnovyd completing his PhD thesis and will start to defending her very soon.

Speaker
Serhii V Krasnovyd SV / PSL Research University Paris,France.

Abstract

With the increased use of photovoltaic electricity generation continuous surveillance the of the system becomes important in order to prevent a partial or complete drop out of supply. Admittance spectroscopy could become a suitable tool for fast failure diagnosis of photovoltaic modules in operation. In a recent work [1] we used a light generated small AC current for admittance studies of single solar cells. This method has advantages compared to conventional small signal admittance spectroscopy. In the later case a DC bias voltage is superimposed by a small sinusoidal AC voltage and applied to the device under test. The AC component of the resulting current then is detected and evaluated by its amplitude and phase relative to the alternating excitation voltage. The bending of the current voltage curve determines the transfer function of the resulting AC current. In many cases only the fundamental order of the current is further processed. In our experiments the illuminated solar cell was terminated with an external resistive load A constant light generated current was superimposed by an alternating component arising from an intensity modulated light source. The resulting AC voltage at the resistive load was detected and evaluated. In this case the transfer function depend on the termination resistor only and ideally is linear. The termination resistor determines the working point on the current voltage curve of the device under test. Experimental instrumentation as well as data evaluation is simple. In my talk I will present results we have obtained so far on small solar modules with intentionally introduced defects.

Biography

V. Schlosser has completed his PhD from the University of Vienna, Austria and postdoctoral studies at the Ludwig Boltzmann Institut für Festkörperphysik, Austria. He is assistant professor at the University of Vienna. He has published more than 70 papers in reputed journals and has been serving as an editorial board member of repute.

Speaker
Viktor Schlosser / Faculty of Physics, University of Vienna, Vienna, Austria

Abstract

Ab initio calculations were used for electronic structure of the ideal and defective semiconductors Cd1-xMnxTe (x=0.01-0.1). It was defined band gap, density of states, total energy, magnetic moments, number of electrons, Fermi levels, defect formation energies and threshold energies. It is determined that the band gap in Cd1-xMnxTe increases linearly with an increase in the Mn concentration, but there occurs an insignificant decrease in the lattice parameter with Mn concentration increasing. It is determined that defects lead to an increase in the band gap width, formation of additional magnetic moments, local levels in the forbidden band, and also to a change in the type of conductivity which are confirmed experimentally. Cd1-xMnxTe epitaxial films were obtained on glass substrates in a vacuum (12)10-4Pa by the Molecular Beams Condensation method. It is determined the optimal conditions for the production of epitaxial films with perfect structure and a clean, smooth surface, without the inclusion of the second phase by using of additional source of Te vapor. Absorption and transmission spectra of Cd1-xMnxTe (х=0.07) epitaxial films on glass substrates of thickness d=15μm and 22μmhave been studied. The band gap width of Cd1-xMnxTe (х=0.07) epitaxial films was Eg=1.73eV.The studies of the effect of γ-radiation on the optical properties of epitaxial films showed that there occurs a change in the band gap width, absorption and reflection coefficients, which can be explained by the appearance of the local levels from the formation of defects. Results corresponds to our theoretical calculations

Biography

Matanat Mehrabova has completed her PhD from Institute of Space Research, Baku, Azerbaijan and postdoctoral studies from Institute of Radiation Problems of Azerbaijan National Academy of Sciences, Baku, Azerbaijan. She is the leading researcher in theInstitute of Radiation Problemsof ANAS. She has published 150 scientific papers, more of them in reputed journals and has been serving as an editorial board member of repute.

Speaker
Matanat Mehrabova / Researcher,National Academy of Sciences,Baku, Azerbaijan

Abstract

Modifications of the surfaces of bismuth thin films with a layer of antimony were carried out to study the changes in adhesion in recrystallized films. The report will describe the possibility of reducing the possible thickness of the recrystallized film by using a sublayer. The surface roughness is altered in the presence of a sublayer and without it. The results of measuring the galvanomagnetic properties block and single films types of structures on substrate of mica: bismuth film, antimony layer as the underlayer film of bismuth.

Biography

Natallya Kablukova received her candidate’s degree in physical and mathematical sciences in Herzen State Pedagogical University of Russia. She has published 11 papers in reputed journals.

Speaker
Natalia Kablukova / Herzen State Pedagogical University of Russia, Sankt-Petersburg, Russia

Abstract

To study the classical size effect, perfect objects are required. The creation of an ideal lattice in thin films is possible not by a large number of methods: thermal deposition with certain substrates and the band recrystallization method [1,2]. These methods make it possible to obtain bismuth and bismuth-antimony films with a single-crystal lattice. In this case, the manifestations of the classical size effect are possible on not very ideal objects, for example, on crystals lattice with twins. And also the dimensional effect exists at grain boundaries in block films. These and other features of the thin-film state make it possible to obtain unique properties when using a small amount of semimetal compounds in combination with a thickness and a substrate. In this paper, we will dwell on the methods for obtaining single-crystal films, the appearance of the classical size effect in the structures obtained on the basis of bismuth and bismuth-antimony.

Biography

Natallya Kablukova received her candidate’s degree in physical and mathematical sciences in Herzen State Pedagogical University of Russia. She has published 11 papers in reputed journals.

Speaker
Natalia Kablukova / Herzen State Pedagogical University of Russia, Sankt-Petersburg, Russia

Abstract

Undoped and lithium doped zinc oxide thin films were deposited by electrodeposition technique from aqueous solution onto ITO substrates at optimum conditions. The variations of the structural, electrical and optical properties with the doping concentration were investigated. XRD analysis showed typical patterns of the hexagonal ZnOstructure for both doped and undoped films. The films were polycrystalline with the (002) preferred orientation. No diffraction peaks of any other structure were found. The grain size and optical band gap were evaluated for different doping concentrations. The films with 5.10-6 M Lithium had a high crystallographic quality and a resistivity of 3,9.10-4 Ω.cm with an energy band gap of 3,3 eV. It is very obvious that ZnO-Li films fabricated by electrodeposition at optimum conditions are suitable for optoelectronic applications, especially those requiring transparent electrodes.

Biography

Speaker
EL HICHOU Ahmed / University Cadi Ayyad

Abstract

Great attention has been devoted to the preparation and characterization of organic-inorganic hybrid perovskites (OIHs). These advanced materials can provide low cost materials for self assembly quantum well applications, fuel, solar cells, batteries, electronic and optoelectronic applications. Diammonium halide perovskite hybrids [NH3(CH2)nNH3]MClxBr4-x ; x= 0, 2, 4; M= Co, Mn; n= 4-9 allow mixing of organic and inorganic components in one molecule which possesses a property that may not exist in either of the parent components. Possibilities could elaborate hybrid materials in terms of processing new chemical and physical properties according to the application needed. Single crystals were prepared by slow evaporation. The complete structure information as well as lattice parameters for Co series n= 4-9 are provided, and for n = 5-6 for Mn hybrid. Differential thermal analysis DSC shows reversible order - disorder transition for both the Co and Mn hybrids. Permittivity studies confirm the phase transition. The optical properties of Co series show strong absorption in the visible range from 500 to 700 nm. The calculated band gap energy using Kubelka-Munk equation ranges from 1.75 eV for [NH3(CH2)9NH3]CoCl4 denoted C9CoCl to 1.73 eV for [NH3(CH2)5NH3]CoCl2Br2 denoted C7CoCB. These values are very promising for lead free hybrid perovskite solar cell. Electronic structure and chemical bonding in Co, Mn OIHs were studied by X-ray (XPS) photoemission spectroscopy. All elements of Co and Mn organic-inorganic hybrid perovskites were found in XPS spectra and can be related to the peaks of N1s, C1s, Co2p, Mn2p and Cl2p. Wide peak of C1s spectra was related to the chemically unequivalent C atoms in the compounds. The spectrum of the N1s level with binding energies of 401.2 eV was assigned to NH3-group. The analysis of Co2p states in Co OIHs compounds shows the divalent state of Co with a typical satellite structure.

Biography

Speaker
Seham K Abdel-Aal / Faculty of Science, Cairo University, 12613 Giza, Egypt.

Abstract

Nanocrystals (NCs) of wide-gap semiconductors A2B6, owing to their high luminescence quantum yield, are widely used in different areas of optical- and nanoelectronics for creating the light-emitting devices, night vision devices, solar batteries, as fluorescent markers for medical diagnosis and so on. Nowaday challenge is development of the technologies for formation of nanostructures directly in polymer matrices.This report describes the in-situ synthesis of NCs of ternary semiconductors Cd1 xCuxS and Cd1 xZnxS inside polymer films, as well as the results of investigations of their structure and optical properties. It has been established that, in the case of Cd1 xCuxS within a large range of Cu to Cd ratios, the hexagonal structure is dominating in the NCs synthesized, while in the case of Cd1 xZnxS the dominating crystalline structure of NCs corresponds to the cubic structure of CdS. However in both cases formation of separate phases of either CdS and CuS or CdS and ZnS has not been revealed. The photoluminescence (PL) spectra of both the Cd1 xCuxS NCs and the Cd1 xZnxS NCs consist of two impurity bands and an exciton band; and their intensity depends on the NCs composition of these semiconductorsin different ways. For the Cd1 xCuxS NCs, a decline of the impurity PL intensity is observed with increasing Cu content. On the contrary, for Cd1 xZnxS NCs, an increasing Zn content in the NCs results in an increase in the intensity of the impurity PL. The possible reasons for these phenomena are discussed.

Biography

Speaker
Viktor Tokarev / Institute of Semiconductor Physics, Ukraine.

Abstract

Detailed theoretical researches of propagation of charge carrier fluxes through boundary of solid-state structure and near to it taking into account dispersion of carriers on boundary is actual and is very claimed by practice. Such researches are especially important in case of presence in solid-state structure of thin layers when at propagation of the fluxes there is their nonsingle scattering on both boundaries of the layer and the usual phenomenological description appears not quite adequate. It also considerably influences properties of a layer as a whole as scattering of differential fluxes of charge carriers on the boundary, depending on its submicronic configuration and a state, usually essentially differs from scattering of fluxes in the thin of layer. This fact is necessary for regarding both in balance, and at its lack. Effects of detailed examination of distribution of differential and integrated fluxes of charge carriers within the limits of the kinetic theory taking into account dispersion of fluxes on boundaries of a plane-parallel layer of solid-state structure are given at the isotropic dispersion relation. In boundary conditions in an integrated view scattering of all interior and all exterior impinging on boundary from the adjacent layers of differential fluxes of charge carriers was considered. It is shown that in balance and at its infringement propagation of differential fluxes of charge carriers at boundary and through boundary, including their loss on boundary, and also a distribution function of charge carriers on a wave vector and co-ordinates crossly in coordination depend on a configuration and a state of a layer’s boundaries, which are characterized by probability of fluxes dispersion. Compounded on layers of structure the solution allows to spot all differential and integrated fluxes of charge carriers in any location of structure section, and also loss of charge carriers on each boundary between layers. The given researches are necessary not only for the correct understanding of a physical pattern of propagation of charge carriers fluxes in a layer, depending on a submicronic structure and a state of its boundaries, but also for correct interpretation of the experimental data, a concerning layer or the structure containing layer.

Biography

Kerimi Muhamed Begenchevich - has graduated from the Leningrad university, chair of quantum mechanics, also has started to work at Physico-technical institute of Turkmenistan Academy of Sciences in 1976. Candidate work was carried out at the Leningrad Physical-technical institute of a name of A.F.Ioffe AoSci by the USSR where I has been attached. The dissertation theme is connected with photon carrying over of a charge carriers in grade band gap semiconductors (or in the smooth heterostructure) GaAlxAs1-x type. In 1987 has received a scientific degree of the candidate of physical and mathematical sciences. Recently I work in the Center of technologies Turkmenistan state AoSci in laboratory Nanotehnologies as the leading research assistant. For all operating time it is published more than 80 materials of scientific works, including materials of the international scientific conferences. In specialized journals with high scientific reputation it was published not much.

Speaker
Kerimi Muhamed Begengchewich / Centre of technologies of the Turkmenistan state Academy of Sciences, Ashgabat, Turkmenistan

Abstract

Silicon nanocrtstals embedded into insolating SiO2 matrix have perspectives for variety of applications, namely: nanocrystal nonvolatile memory, resonant-tunneling structures, single electron transistors etc. The photoelectric properties of layered SiO2-SiO2(Si)-SiO2 structure on silicon substrate have been investigated in this work. At the beginning the ultrathin SiO2 layer with different thickness in the range of 2 – 15 nm has been thermally grown on silicon wafer in dry oxygen. On the second stage the silicon enriched SiOx (x<1) film has been deposited by ion-plasma sputtering (IPS) of Si target in oxygen and argon ambient. The upper control SiOx (x2) layer was also deposited by IPS method. The following high temperature annealing at T=1100 C caused phase separation of middle SiOx film and, as a result, the Si nanocrystals have been formed. After that the transparent conductive layer (ITO) has been deposited on the top of multilayer structure. The charging of Si nanocrystal has been performed by pulse of positive voltage. Negative charge captured on nanocrystals changes the surface potential and in such a way the upper energy band bending was created at the surface region. The following illumination of such structure by light generates the electron-hole pairs which are separated by surface energy barrier. The difference of potentials has been observed between front and back sides of the structure. The influence of the trapped charge value on the potentials difference and its changing with time of illumination has been investigated. The observed effects can be used in novel solar cells and photodetectors.

Biography

Volodymyr Lytovchenko was born in Ukraine, Kiev district (24.12.1931). Graduated radio-physical faculty Kiev State University (1955) on semiconductor subject, postgraduated in of Institute Physics (1956-59), obtain Dr. (1960), Dr. of Sci. (1970), member-corr. Nat. Acad. Sci. of Ukraine (1985), Prof. Kiev Univ. (1974), Soros Prof. (1980), President Ukr. Phys. Soc (2004-2012), member of editorial board some of international phys. journals (Surface Science, Thin Solid films; Low. Dim.Str. Ukr. Phys. Journal etc. Published 11 monographs (incl. on Surf. Electron Transportin in Oxford Sci. Publ.). Now is a chief of Phys. Sci. Surface Dpt., Inst. Semiconductor Phys. Ukr. Acad. of Sci.

Speaker
Volodymyr Lytovchenko / Institute of Semiconductor Physics, National Academy of Science of Ukraine

Abstract

Is presented the review of experimental and theoretical studies of nano-films PECVD deposition with advanced DC cylindrical magnetron systems in the Department of Gas Electronics of Institute Physics of NASU. The plasmaoptical model of cylindrical magnetrontype gas discharge is presented[1-3]. The model is based on the assumption about the presence of three quasiautonomous regions in the diode gap of the discharge, at that the regions possess essentially different mechanisms of current transfer. Is shown a possibility of nondestructive online monitoring of film quality with optical emission spectroscopy. The optical monitoring based on analysis of the spectrum lines provides extensive information and makes it possible to simultaneously trace the behavior of several components of the gaseous medium in which a reactive plasma is generated. The optical method of controlling the plasma medium of the inverted cylindrical DC magnetron can be used to detect the working point of deposition, for example, of titanium oxide or titanium nitride films, including stoichiometric. The variation of deposition conditions allows variating different characteristics of deposited film

Biography

Speaker
Dobrovolsky Andriy / Institute of Physics, Ukraine

Abstract

Spinel is one of the largest groups of inorganic compounds existing in nature and also draws great attentions since this close-packed structure possesses many enormous properties, which could apply in various industrial fields like magnetic materials [1], electrical materials [2], high frequency devices [3]. Due to their potential usage in various technological applications studies about spinel type structures are promising. So, in this study we have studied structural, electronic, optical and vibrational properties of different spinel type structures using density functional theory calculations together with PBE exchange correlational functional. All electronic structure calculations are carried out using VASP software. From band structure calculations it has been observed that studied spinels have certain band gaps which make them good candidates for semiconductor applications.

Biography

Salih Akbudak has completed his PhD from Hacettepe University Institute of Science, Nanotechnology and Nanomedicine Division, TURKEY in March 2016. During his doctoral studies he has been a visiting scholar in Fritz-Haber Institute of Max-Planck Society, Berlin, GERMANY between 1 september 2014 and 1 september 2015. He has carried out theoretical calculations of his PhD thesis in Fritz-Haber Institute of Max-Planck Society. He has published a total of 9 papers and 7 of them are in SCI journal.

Speaker
Salih Akbudak / Department of Physics, Faculty of Arts and Sciences, Adiyaman University, Turkey.

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