Browsing by Author "Goglidze, Tatiana"

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(As 2 S 3 ) x -(As 2 Se 3 ) 1-x THIN FILMS FOR GAS SENSING APPLICATIONS
(CEP USM, 2007) Dmitrev, Serghei; Goglidze, Tatiana; Dementiev, Igor; Pocotilov, Evghenii; Lad, Robert; Vetelino, John
În lucrare sunt prezentate rezultatele elaborării tehnologiei de obţinere şi cercetare a proprietăţilor electrofizice ale straturilor subţiri (As2S3)x-(As2Se3), destinate în calitate de elemente gazosensibile ale detectoarelor. Straturile subţiri au fost depuse prin metoda evaporării termice în vid ( P=10-5 Torr) pe suporturi dielectrice. Grosimea straturilor depuse varia între 0,5 şi 2 μm. Cercetarea influenţei componenţei materialului sursăşi a unui sir de parametri tehnologici ai depunerii asupra rezistivităţii, concentraţiei capcanelor şi a benzii interzise în straturile obţinute a demonstrat că în dependenţă de mărimea x rezistivitatea se schimbăde la 1010 până la Ohm·cm, concentraţa capcanelor în regiunea (2,1-7,9)х1016см-3şi a benzii interzise ΔEg – de la 1,75 până la 2,35 eV corespunzător. Pentru cercetarea sensibilităţii gazoase faţă de gazele CO şi NO2 prin metoda depunerii consecutive în vid au fost obţinute structurile săndvici de Al/As-S-Se/SnO2. Structurile obţinute au demonstrat o sensibilitate mai pronunţată la NO2, decât la monooxidul de carbon.
CONVERTER OF X-RAY RADIATION ON THE BASIS OF A2B6-LAYERS OBTAINED BY A METHOD OF CHEMICAL PULVERIZATION
(SPIE, 2005) Goglidze, Tatiana; Dementiev, Igor; Cortiucova, Iulia; Mațcova, Natalia
THE ELECTRICAL TRANSPORT MECHANISM IN THE (nCdS–рAs 2Se3 ) HETEROJUNCTIONS
(2008) Goglidze, Tatiana; Dementiev, Igor; Dmitriev, Serghei; Nasedchina, Nadejda; Mațcova, Natalia
In the given paper we present results of I-V characterization of thin film heterojunctions on the basis of (nCdS)–(рAs 2 Se3 ). Structures have been obtained via spray pyrolysis deposition of polycrystalline nCdS layers on glass substrate and consecutive thermal vacuum deposition of the amorphous рAs 2 Se3 layers. The possible mechanisms of the current passing through obtained structure are discussed on the basis of results of I-V measurements performed at the different polarities and electrical field intensities in the heterojunction.
INFLUENCE OF ZNS NANOPARTICLES ON PRODUCTIVITY OF RED ALGAE PORPHYRIDIUM CRUENTUM
(Полиграфист, 2014-11-14) Goglidze, Tatiana; Dementiev, Igor; Guțul, Tatiana; Dvornicov, Dmitrii; Mironic, Tatiana; Rudi, Ludmila; Cepoi, Liliana
Наночастицы ZnS были синтезированы с использованием коллоидных методов, Для получения водного коллоидного раствора, поверхность частиц была модифицирована тиоглицеролом. Наличие тиоглицерола на поверхности наночастиц было подтверждено с помощью инфра- красной спектроскопии. Водный раствор наночастиц ZnS был протестирован на красных водорослях Porphyridium cruentum, которые были использованы в качестве биологического объекта.
LUMINESCENT PROPERTIES OF LOW-DIMENSIONAL ZnO:Ag POWDERS OBTAINED BY CHEMICAL DEPOSITION FROM AQUEOUS SOLUTION
(2023) Goglidze, Tatiana; Goncearenco, Evghenii; Dementiev, Igor; Nedeoglo, Natalia; Iurieva, Tatiana; Nedeoglo, Dumitru
Photoluminescence (PL) spectra of ZnO:Ag highly dispersed powders obtained by chemical deposition from aqueous solution are investigated in the wavelength range between 360 and 750 nm at room temperature under excitation between 250 and 350 nm. Before starting the synthesis, the Ag dopant was introduced into the initial solution in the form of AgNO3 silver nitrate in the amount of 12, 102, and 252 mg. The PL spectra consist of an ultraviolet emission (380 nm) attributed to AgZn acceptor-bound exciton, a short-wavelength violet emission (400 –450 nm) and a wide long-wavelength yellow-orange emission (560 – 600 nm). With decreasing excitation energy, the violet emission decreases in intensity, while the yellow-orange emission increases. This is caused by the phenomenon of self-absorption of the short-wavelength emission and energy transmission to the centers of the long-wavelength emission. A rapid decrease in intensity of all the PL bands is found for the sample with maximum Ag concentration. This fact is due to the appearance of the second phase in the form of silver oxide and, consequently, a decrease in the concentration of AgZn point defects responsible for the bands.
LUMINESCENT PROPERTIES OF ZnO POWDERS SYNTHESIZED BY THE ISOVALENT SUBSTITUTION METHOD
(2016) Goglidze, Tatiana; Dementiev, Igor; Koval, Andrei; Nedeoglo, Natalia; Nedeoglo, Dmitrii
Zinc oxide powders have been prepared by the isovalent substitution method by means of high - temperature annealing of a zinc sulfide powder synthesized by a chemical method. Investigation of photoluminescence (PL) spectra in dependence on annealing temperat ure varied from 870 to 1050  С has made it possible to find the temperature range of 920 – 950  С for the most active isovalent substitution of oxygen atoms for sulfur atoms and the formation of a ZnO  S phase. X - ray diffraction analysis has revealed that the p owder with crystal lattice parameters а о = 0.3249 nm and с о = 0.5206 nm and the ratio of с о / а о = 1.60, which are characteristic of zinc oxide crystals, is synthesized at the maximum annealing temperature. It has been found that the maximum of a structurel ess PL band in the spectrum for the ZnO powder at room temperature is localized at 500 nm. It has been supposed that the band is caused by ―free electron – acceptor‖ radiative transitions, where the acceptor level is 0.95 eV above the valence band edge.
LUMINESCENT PROPERTIES ON ZnO:Cr NANOCRYSTALS AND THIN LAYERS
(Springer Nature, 2020) Goglidze, Tatiana; Dementiev, Igor; Goncearenco, Evghenii; Iurieva, Tatiana; Nedeoglo, Dumitru; Nedeoglo, Natalia
Both undoped and chromium doped zinc oxide nanocrystal powders are obtained by chemical deposition and hydrothermal methods. ZnO and ZnO:Cr thin layers on the surface of ZnSe and ZnSe:Cr samples, respectively, are obtained by isovalent substitution of selenium by oxygen in the process of thermal treatment of the samples in air. Photoluminescence spectra of the ZnO and ZnO:Cr nanopowders and thin layers obtained by various techniques are investigated at room temperature. Cr doped ZnO powders obtained by chemical deposition and hydrothermal methods improves the powder quality, as evidenced exciton emission is more intensive. New emission bands are found in visible (615 nm, 625 nm) and infrared (925 nm, ~2000 nm) spectral ranges for ZnO:Cr nanopowders and thin films. The contribution of Cr impurity to the formation of emission bands is discussed.
PREPARATION OF NANOCOMPOSITE CADMIUM SULFIDE IN A POLYMER MATRIX
(2010) Goglidze, Tatiana; Gutsul, Tatiana; Dementev, Igor; Petrenko, Piotr
A technique for formation of CdS nanocrystals in a Sevilen polymeric matrix by the cluspol method is proposed. The optimum conditions of synthesis of CdS nanocrystals are found. The crystallite sizes are estimated using the X-ray diffraction analysis. The results of studying the luminescent properties of the resu ltant polymer + nanodimensional CdS structures are described.
STUDY OF MULTIPLE RECORD OF THE OPTICAL INFORMATION ON PHOTOTHERMOPLASTIC MEDIUMS (PTPM) IN THE HOLOGRAPHIC WAY
(SPIE, 2007) Goglidze, Tatiana; Dementiev, Igor; Cortiucova, Iulia; Mațcova, Natalia
In the given work results of experiments on carrying out of cyclic record on PTPM are resulted by holographic way. The optical scheme is resulted, allowing automating process of record of elementary holograms in the form of diffraction gratings on PTPM and their definitions diffraction efficiency. The mechanism of occurrence of "parasitic" memory PTPM due to photostructural transformations into thin layers CGS is considered.