N. V. Gaponenko

N. V. Gaponenko
Belarusian State University of Informatics and Radioelectronics · Department of Micro- and Nanoelectronics

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168
Publications
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Publications

Publications (168)
Article
Photo- and cathodoluminescence in the visible range from erbium-doped barium titanate xerogels obtained in the form of a powder and a target pressed from it by explosive compaction are investigated. The powder and target exhibit upconversion luminescence of erbium ions excited at wavelengths in the regions 950–1000 and 1450–1550 nm that is characte...
Article
Исследована фото- и катодолюминесценция видимого диапазона в легированных эрбием ксерогелях титаната бария, полученных в виде порошка и мишени, спрессованной из него методом взрывного прессования. Порошок и мишень демонстрируют ап-конверсионную люминесценцию ионов эр- бия при возбуждении на длинах волн в областях 950—1000 и 1450—1550 нм, которая ха...
Article
Erbium-doped barium titanate (BaTiO 3 :Er) xerogel film with a thickness of about 500 nm was formed on the porous strontium titanate (SrTiO[Formula: see text] xerogel film on Si substrate after annealing at 800[Formula: see text]C or 900[Formula: see text]C. The elaborated structures show room temperature upconversion luminescence under 980 nm exci...
Article
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Lead halide perovskite quantum dots (PQDs) are reported as a promising branch of perovskites, which have recently emerged as a field in luminescent materials research. However, before the practical applications of PQDs can be realized, the problem of poor stability has not yet been solved. Herein, we propose a trioctylphosphine (TOP)-assisted pre-p...
Article
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Very recently, ultrathin perovskite nanostructures, taking the advantages of perovskite as well as the ultrathin properties, have received an enormous level of interest due to their many fascinating properties, such as stronger quantum confinement effect and larger specific surface area. In spite of this incredible success in perovskite nanocrystal...
Article
Sol-gel barium titanate films on quartz substrates annealed at 450, 600, and 700°C were studied using spectral ellipsometry and spectrophotometry in the region of intrinsic absorption bands to determine the thicknesses of surface layers, films, and film–air and fi lm–substrate transition layers. Decreases of the band gap, porosity, and thickness of...
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Eu3+ doped porous nanostructured SrTiO3 films and powder fabricated by sol-gel route without using any precursor template are characterized by different morphology and phase composition. The films show red and yellow luminescence with the most intensive photoluminescence (PL) bands at 612 nm and 588 nm, respectively. Raman, secondary ion mass spect...
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Very recently, two-dimensional (2D) perovskite nanosheets (PNSs), taking the advantages of perovskite as well as the 2D structure properties, have received an enormous level of interest throughout the scientific community. In spite of this incredible success in perovskite nanocrystals (NCs), self-assembly of many nanostructures in metal halide pero...
Conference Paper
A brief summary of experimental data on the production of nanostructured yttrium aluminum garnet powders doped with lanthanides and combined coatings from suspensions based on these powders and film-forming sols is given. The results of structure analysis of powders and luminescence of lanthanides in the resulting coatings are presented. The prospe...
Article
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Sol–gel technology was applied to fabricate Eu-doped BaTiO 3 /SiO 2 multilayer structures by spinning on silicon and fused silica substrates. Eu photoluminescence (PL) was investigated depending on the annealing temperature of these structures. The samples demonstrate the room temperature luminescence corresponding to ⁵ D[Formula: see text]F J ([Fo...
Article
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The objective of the work is investigation the dielectric permittivity and dielectric loss tangent of BaTiO3 films in a capacitor structure formed by sol – gel method on a Si/TiOx/Pt substrate. The basis of this capacitor is a four-layer film of barium titanate xerogel with a thickness of about 200 nm. The film was synthesized by sol-gel method at...
Article
Full-text available
Among the leading energy materials, metal tri-halide perovskite quantum dots (PQDs) with outstanding optoelectronic properties are still at the forefront of current research. However, the enormous challenges, including hazardous components and poor stability, remain to be addressed urgently problems before fulfilling its practical applications. Alt...
Article
The presented paper deals with the measurement methodologies of the structural properties of porous anodic alumina (PAA) films filled with YAlO 3 :Tb ³⁺ composite using X-ray diffraction, atomic force microscopy and scanning electron microscopy. It shows that the deposited material does not uniformly fill the porous volume of the anodic alumina fil...
Article
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This paper presents the study of the optical properties of multilayer periodic structures, such as Bragg reflector, with different synthesis conditions. Transmission, reflection, luminescence, luminescence excitation spectra and kinetics of luminescence are presented for the Bragg reflectors formed on quartz with 6 and 12 alternating layers BaTiO3:...
Article
We report on the sol-gel synthesis and optical properties of an Eu-doped multilayer structure consisting of a Bragg reflector/BaTiO3:Eu/Bragg reflector, with the Bragg reflector comprising of BaTiO3/SiO2 structures. Depending on the fabrication procedure two set of specimens were generated with Eu out of the cavity or Eu in the cavity. Enhanced Eu...
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We show CsPbBr3 nanowires (NWs) are formed by the hierarchical arrangement of individual nanoparticles (NPs), and reversible transformation from NWs to NPs are also achieved by anion exchange.
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Fully dielectric solar control coatings based on alternating layers of Ba (or Sr)TiO3 and MgF2 were deposited on soda lime glass substrates. Three-layered stacks BaTiO3/MgF2/BaTiO3 and SrTiO3/MgF2/SrTiO3 were generated using BaTiO3, SrTiO3 and MgF2 sols deposited on glass using dip coating technique. The multilayered coating stack was fired at 450...
Article
SrTiO 3 and SrTiO 3 :Nd films of 110[Formula: see text]nm and 210[Formula: see text]nm thickness were fabricated using the sol–gel technology on silicon. Their current–voltage characteristics were investigated with and without illumination. The film structures are photosensitive and exhibit the hysteresis on the forward and reverse bias with loop b...
Article
With the use of sol–gel method BaTiO 3 –SiO 2 multilayer structures were fabricated on glass or fused silica substrates employing dipping or spinning procedure. The photonic stop band was observed in the reflection and transmission spectra of the multilayer structure annealed at [Formula: see text]C. It is redshifted with an increase of the thickne...
Article
Multi-layer film structures BaTiO3/SiO2 with a thickness of ~1 μm containing up to 14 pairs of layers were synthesized by the sol–gel method with sequential heat treatment. It is shown that the synthesized structures are X-ray amorphous. The formation of bands in the transmission and reflection spectra caused by interference effects is demonstrated...
Article
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In this work, we investigate photoluminescence of sol-gel derived films corresponding to yttrium alumina garnet Y3Al5O12 doped with trivalent europium. The films with three concentrations of europium 0,02; 0,025; 0,03 M with the thickness 210-220 nm were deposited on fused silica substrates by the corresponding sols' spinning followed by drying and...
Article
In this work, the Stokes and anti-Stokes luminescence (upconversion) of erbium in powders of yttrium-aluminum garnet with various concentrations of erbium, as well as co-doped with erbium and ytterbium, synthesized by the sol-gel method using multistage thermal processing, was investigated. It was established that the phase composition of the resul...
Article
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Изложены обобщенные модельные представления, описывающие процесс образования дисперсных включений новых фаз различного стехиометрического состава на границах раздела в поликристаллических пленках многокомпонентных сегнетоэлектрических оксидов за счет процессов объемной диффузии, зернограничной сегрегации и взаимодействия с подложкой. Целью работы я...
Article
Using data of multiangle spectrophotometry and spectral ellipsometry in the UV and visible ranges, spectra of the refractive indices and absorption coefficients and width of the forbidden band of one- and five-layer strontium titanate films obtained by the sol–gel method have been calculated. Layer-by-layer deposition of sol on quartz substrates, f...
Chapter
Terbium, ytterbium and europium doped strontium titanate thin films and undoped strontium titanate powder were synthesized using sol-gel method. Xerogel was deposited by spin-on technic on monocrystalline silicon and porous anodic alumina substrates formed on monocrystalline silicon. Structure and photoluminescence of obtained films were investigat...
Chapter
Luminescent structures presented monocrystalline silicon and porous anodic alumina with neodymium doped yttrium alumina composites YAC:Nd that were formed by sol-gel route from different sols. Structure, phase composition and luminescence of the obtained structures were investigated. Photoluminescence spectra of structures containing YAC:Nd carry e...
Article
Films of Eu-doped yttrium–alumina composites (YAG:Eu) with Eu concentrations of 0.020, 0.025, and 0.030 M were synthesized by the sol-gel technique. The films were fabricated by centrifugation onto fused silica followed by heat treatment. It was shown that spectra of films that were heat treated at 800–1200oC for 30 min exhibited luminescence bands...
Article
The transmission spectra of films of strontium titanate up to 200 nm thick produced on quartz glass substrates by the sol-gel method were investigated in the region of 200–1100 nm. The sol was prepared from strontium acetate, titanium tetraisopropoxide, acetic acid, and ethylene glycol monomethyl ether. The strontium titanate films were formed by s...
Article
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The changes in the electrical resistance of a strontium titanate film prepared by sol-gel method under the influence of pulsed and linearly increasing voltage are considered.
Article
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The photoluminescence properties of a composite material prepared by the introduction of the nanosized phosphor Zn2SiO4:Mn²⁺ into porous anodic alumina have been investigated. Scanning electron microscopy studies have revealed that Zn2SiO4:Mn²⁺ particles are uniformly distributed in 70% of the volume of the pore channels. The samples exhibit an int...
Article
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Yttrium–aluminum composites doped with terbium were synthesized by precipitation on porous anodic alumina fi lms grown on silicon substrates. The fabricated structures demonstrated x-ray-, cathodo-, and photoluminescence with characteristic bands of trivalent terbium upon excitation by Cu Kα x-rays of energy 8.86 keV, a 180-keV electron beam, and o...
Article
Luminescent structures of yttrium aluminum garnet doped with rare-earth elements Tb and Nd (YAG:Tb3+ and YAG:Nd3+) were formed by the sol–gel route on films of porous anodic alumina. The morphology, phase composition, and luminescence of the fabricated structures were investigated. Photoluminescence spectra of the YAG:Tb3+ and YAG:Nd3+ structures r...
Article
Full-text available
Using the sol-gel method, strontium titanate films were prepared (strontium titanate xerogels) on monocrystalline silicon substrates at 750°C annealing temperature. Nickel upper electrodes were deposited by magnetron sputtering, and the current–voltage characteristics were measured for the prepared structures with two upper electrodes and a Schottk...
Article
A thin-film ferroelectric capacitor was produced on a silicon substrate. A multilayer strontium titanate film of 280 nm thickness is the base of the capacitor. This film was made by the sol gel technique at the annealing temperature of 750°C. The bottom electrode was produced from platinum and the upper one was produced from nickel. The mean value...
Article
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A change in the resistance of strontium titanate structures formed by the sol–gel method has been demonstrated. The transition of a strontium titanate film with a thickness of about 300 nm from the highresistance to low-resistance state occurs when the bias voltage on the silicon/titanium dioxide/platinum/strontium titanate/nickel capacitor structu...
Article
Full-text available
Terbium-doped strontium titanate thin films are synthesized via the sol–gel method. The xerogel is deposited onto single-crystal silicon and porous anodic alumina substrates formed on single-crystal silicon. The structure and phase composition of the films are studied. The strontium titanate xerogel on single-crystal silicon exhibits a photolumines...
Chapter
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Thin film SrTiO3capacitors were fabricated on silicon using the sol-gel method. Thedependence of capacitance onvoltage was observed atthe room-temperature andfrequency of 1MHz. Tunable dielectric properties of thethin films are discussed.
Article
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Films of titania (TiO2) and titania modified with gold nanoparticles (TiO2:Au) were synthesized by a sol-gel method on substrates of glass, aluminum, and aluminum with a layer of nanotextured aluminum or porous anodic alumina. The photocatalytic activity of the samples was investigated in an aqueous solution of the antibiotic tetracycline hydrochlo...
Article
Full-text available
Strontium-titanate films obtained by the sol-gel technique are deposited onto silicon and silicon/oxide titanium/platinum substrates. The strontium-titanate phase is detected by the method of X-ray diffraction analysis after heat treatment at temperatures of 750 and 800°C. The thickness of the films obtained by the spin-on method increases from 50...
Article
We report on synthesis and photoluminescence of sol-gel derived terbium doped strontium titanate on monocrystalline silicon and in the porous anodic alumina matrix. The microstructure and morphology of the samples are analyzed by X-ray diffraction and scanning electron microscope analyses. The thickness of the spin-on films deposited on silicon is...
Article
In this work, terbium and europium doped YAlO3 phosphors were synthesized by sol-gel method. It has been shown that after annealing at 1000 °C these phosphors crystallize in the cubic garnet phase, similar to Y3Al5O12. As evidenced by the time-resolved photoluminescence spectroscopy and Maximum Entropy Method, the photoluminescence decay of both eu...
Article
Full-text available
Terbium doped YAlO3 composites, with terbium concentrations up to 2.11 at%, were fabricated by co-precipitation in porous anodic alumina films grown on silicon. The presence of the cubic YAlO3 phase was confirmed by x-ray diffraction and FT-IR analysis. The fabricated samples demonstrate photoluminescence (PL) within the range 350–640 nm, which is...
Conference Paper
Full-text available
The photocatalytic degradation of Rhodamine C under UV illumination of titanium dioxide deposited into mesoporous anodic alumina films has been investigated. A complete photomineralization of the dye was observed along with accompanying stepwise cleavage of diethylamino groups without changing the chromophore structure.
Article
Terbium doped YAlO3 xerogels were synthesized and spin-coated onto porous anodic alumina substrates. After deposition the films were annealed at temperatures between 400 and 1000 °C. The influence of the annealing temperature on terbium emission and the terbium excitation mechanism were investigated by means of photoluminescence, photoluminescence...
Article
In this work, sol–gel derived titania (TiO2) in porous anodic alumina (Al2O3) support has been demonstrated as efficient photocatalytic coating. Its photocatalytic performance after calcination at 400 °C correlates with the size of the pores and the thickness of the porous support providing strong photocatalytic activity for the porous anodic alumi...
Conference Paper
The strontium titanate thin films were fabricated on silicon using the sol-gel method. The strontium titanate phase was registered with X-ray diffraction analysis. The films were deposited by spin-on technique and the film thickness was in the range of 90-115 nm. The perspectives for development of the sol-gel method for the formation of memristors...
Conference Paper
Full-text available
Terbium-doped yttrium aluminum composite was synthesized by the co-precipitation method. The deposition was made by spinning of the aqueous-alcoholic solution of aluminum and yttrium salts on a porous anodic alumina formed on a monocrystalline silicon substrate. The YAlO3 phase was revealed after the heat treatment at 1000° C. The terbium luminesce...
Article
We have used porous anodic alumina (PAA) films as templates for embedding rhodamine 110 (Rh110) molecules and examined their photoluminescence (PL) properties in detail. The analysis of the polarization memory (PM) of PL strongly suggests that there is a significant energy transfer from PAA to Rh110 molecules. The effect of annealing the PAA layer...
Article
a b s t r a c t The present paper discusses the optical and electrical properties of (Ba 0,6 Sr 0,3 Ca 0,1)TiO 3 (BSCT) doped with Tb 3+ ions and deposited onto nano-porous anodic alumina using sol–gel method. Photoluminescence (PL), PL time-decay and total photoluminescence excitation spectroscopy data obtained from the struc-ture xerogel/porous a...
Article
Full-text available
Photo-, radio-, and pulse cathodoluminescence spectra from sol-gel derived titania, doped with strontium and terbium, deposited on porous anodic alumina (PAA) films are reported. The morphology and qualitative elemental depth distributions have been examined by transmission electron microscopy, scanning electron microscopy, and radio-frequency glow...
Article
In this work, we synthesised xerogels embedded in honeycomb porous anodic alumina films of 1–150μm thickness, with pore diameters of 40–180nm and cell sizes of 120–250nm, and investigated their luminescence and photocatalytic properties. Sols with compositions corresponding to alumina, garnet, willemite and titania in porous anodic alumina films we...
Conference Paper
Full-text available
Photo-, cathodo-, and X-ray luminescence of terbium in sol-gel derived films, fabricated in porous anodic alumina is studied. The cell size of the fabricated film convertor of irradiation is about 250 nm. The methods of increase Tb luminescence under diverse excitation conditions are discussed.
Article
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Terbium-doped alumina xerogel layers are synthesized by the sol-gel method in pores of a porous anodic alumina film 1 μm thick with a pore diameter of 150–180 nm; the film is grown on a silicon substrate. The fabricated structures exhibit terbium photoluminescence with bands typical of trivalent terbium terms. Terbium X-ray luminescence with the mo...
Article
Full-text available
We report results of the search for high energy GRBs and high energy radiation in correlation with GRBs. The search has been performed at "Andyrchy" EAS array, for this purpose the single particle counting rate of the array has been used. The data were collected during 1996 -2006 years with a live time 2290 days.
Conference Paper
The paper reports on synthesis and characterization of the structures on the basis of porous anodic alumina with titania xerogel doped with strontium and terbium. Luminescence of the structure and possibility of application the sol-gel synthesis for the X-ray convertor film with reduced size of the grains is discussed.
Conference Paper
A comparative analysis of photodegradation of tetracycline and the organic dye Rhodamine B in aqueous media in the presence of titania xerogel deposited on glass, aluminium foil and porous anodic alumina of 1.5, 3 N 150 μm thickness has been performed. The samples has revealed effective photocatalytic decomposition of tetracycline and the dye. The...
Conference Paper
In the present paper luminescence from aluminium oxide synthesized in a form of xerogel powders and films doped with terbium, porous anodic alumina with terbium ions deposited from the solution of salt, depending on annealing temperature and terbium concentration is investigated.
Article
Willemite (α-Zn2SiO4) doped with manganese and Tb-doped yttrium alumina garnets (Y2.85 Tb 0.15 Al5O12), were synthesized using sol-gel technique. Photo-, cathodoluminescence and luminescence under X-ray excitation were investigated and under all types of excitation the samples revealed green visible to the naked eye luminescence at room temperature...
Article
The synthesis of titanium dioxide in the pores of porous anodic alumina (PAA) membrane was realized by solgel method. The samples were used for test reaction of degradation of organic dye rhodamine B. The synthesized samples of titanium oxide xerogel in the membrane of porous anodic alumina are considered as effective photocatalyst for decompositio...
Article
We have used the sol–gel method to synthesize titanium dioxide in the pores of an anodic aluminum oxide membrane. The samples were used for the test reaction of degradation of the organic dye rhodamine B. The concentration of the dye rhodamine B was monitored from the change in the absorption spectra in the 554 nm region, for an aqueous solution co...
Article
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Terbium-doped yttrium-aluminum oxide films were synthesized by spin-on deposition on porous anodic alumina grown on a silicon wafer and annealed from 400 to 1100 degrees C. An influence of the annealing temperature on the terbium photoluminescence (PL) was studied using two-dimensional PL excitation and time-resolved spectroscopy. Further, a compar...
Article
We report that the morphologies of porous anodic alumina films are affected significantly by the presence of small amounts of copper impurity in the aluminium substrate, resulting in generation of defects during anodizing in phosphoric acid over a wide range of conditions. The copper is accumulated at the metal/film interface and transported prefer...