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Wpływ wygrzewania na właściwości sensorowe cienkich warstw WO₃

Kapuścik Paulina, Mazur Michał, Wojcieszak Damian

Biuletyn Wojskowej Akademii Technicznej

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2023

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Vol. 72, nr 3

43--52

PL

Trójtlenek wolframu (WO₃) jest półprzewodnikiem o szerokiej optycznej przerwie energetycznej, do jego zalet należą wysoka stabilność chemiczna oraz niska cena. Ponadto ma właściwości chromogeniczne, czyli zdolność do zmian zabarwienia w odpowiedzi na różne bodźce, w tym temperaturę, promieniowanie świetlne, pole elektryczne oraz ekspozycję na wodór. Ze względu na wysoką wydajność barwienia i szybkie przełączanie cienkie warstwy WO₃ mogą być stosowane w lustrach antyodblaskowych i inteligentnych oknach, jak również w czujnikach gazów. W pracy przedstawiono wyniki badań wpływu wygrzewania na właściwości cienkich warstw WO₃ wytwarzanych metodą impulsowego rozpylania magnetronowego (GiMS) z warstwą palladu w roli katalizatora. Próbki były wygrzewane w temperaturach od 200 do 400°C. Odpowiedź sensorową powłok scharakteryzowano na podstawie pomiaru widm transmitancji podczas wprowadzania powietrza i mieszaniny H₂/Ar o stężeniu wodoru od 25 do 1000 ppm. Ponadto zbadano wpływ wygrzewania na strukturę oraz morfologię powłok. Wygrzewanie w temperaturze 400°C spowodowało zmianę struktury powłok z amorficznej na krystaliczną. Po wprowadzeniu mieszaniny H₂/Ar zaobserwowano spadek transmitancji dla wszystkich próbek. Dla warstw wygrzewanych w temperaturze 200°C i 300°C wartość transmitancji spadała podczas całego cyklu barwienia, natomiast w przypadku warstw wygrzewanych w 400°C nasycenie sygnału osiągnięto po 7 minutach. Stwierdzono, że najlepszymi właściwościami sensorowymi charakteryzują się powłoki wygrzewane w temperaturze 400°C, ze względu na wysokie wartości odpowiedzi sensorowej dla bardzo małego stężenia wodoru (SR = 6,3 dla 25 ppm H₂) oraz krótki czas odpowiedzi i powrotu.

EN

Tungsten trioxide (WO₃) is a wide-bandgap semiconductor. its advantages include high chemical stability and low price. Furthermore, WO₃ has chromogenic properties, that is, the ability to switch between pale yellow and dark blue in response to various stimuli, including temperature, light irradiation, electric field, and exposure to hydrogen. Due to its high colouring efficiency and fast switching, it can be used in antidazzling mirrors and smart window applications, as well as in gas sensing. in this paper, we present the influence of annealing on the properties of WO₃ coatings that were annealed at temperatures in the range from 200°C to 400°C. The sensing response was characterized based on the transmittance measurement during exposure to air and Ar/H₂ mixture with hydrogen concentrations from 25 ppm to 1000 ppm. Furthermore, the influence of annealing on the structure and morphology of the coatings was examined. annealing at 400°C led to a structure change from amorphous to crystalline one. after the introduction of the Ar/H₂ mixture, a decrease in transmittance was observed for all of the analysed coatings. For films annealed at 200°C and 300°C, the transmittance value decreased during the entire colouring cycle, while for the coating annealed at 400°C a plateau was reached after 7 minutes of exposure. it was found that the best sensing characteristics were obtained for the WO₃ thin film annealed at 400°C due to high sensor response to very low hydrogen concentrations (SR = 6.3 for 25 ppm H₂) as well as short response and recovery times.

2

Characterization of SnO2/TiO2 with the Addition of Polyethylene Glycol via Sol-Gel Method for Self-Cleaning Application

Halin Dewi Suriyani Che, Azliza Azani, Razak Kamrosni Abdul, Abdullah Mohd Mustafa Al Bakri, Salleh Mohd Arif Anuar Mohd, Wahab Juyana A, Chobpattana Varistha, Kaczmarek Łukasz, Nabiałek Marcin, Jeż Bartłomiej

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

243--248

EN

TiO2 is one of the most widely used metal oxide semiconductors in the field of photocatalysis for the self-cleaning purpose to withdraw pollutants. Polyethylene glycol (PEG) is recommended as a stabilizer and booster during preparation of water-soluble TiO2. Preparation of SnO2/TiO2 thin film deposition on the surface of ceramic tile was carried out by the sol-gel spin coating method by adding different amount of PEG (0g, 0.2g, 0.4g, 0.6g, 0.8g) during the preparation of the sol precursor. The effects of PEG content and the annealing temperature on the phase composition, crystallite size and the hydrophilic properties of SnO2/TiO2 films were studied. The X-ray diffraction (XRD) spectra revealed different phases existed when the films were annealed at different annealing temperatures of 350°C, 550°C and 750°C with 0.4 g of PEG addition. The crystallite sizes of the films were measured using Scherrer equation. It shows crystallite size was dependent on crystal structure existed in the films. The films with mixed phases of brookite and rutile shows the smallest crystallite size. In order to measure the hydrophilicity properties of films, the water contact angles for each film with different content of PEG were measured. It can be observed that the water contact angle decreased with the increasing of the content of PEG. It shows the superhydrophilicity properties for the films with the 0.8 g of PEG annealed at 750°C. This demonstrates that the annealed temperature and the addition of PEG affect the phase composition and the hydrophilicity properties of the films.

3

Modification of semiconducting copper oxide thin films using ion implantation

Ungeheuer Katarzyna, Marszalek Konstanty, Mitura-Nowak marzena, Kakol Zbigniew

Przegląd Elektrotechniczny

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2022

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R. 98, nr 9

255--258

EN

The article describes method of Cr+ ion implantation with energy of 10 keV and 15 keV. This method can be used to modify thin film semiconductors. Simulations of implantation process were performed using the Stopping and Range of Ions in Matter software, taking into account different energies of the ion beam. The apparatus diagrams of ion implantation and magnetron sputtering processes are presented. Optical and structural properties of non-implanted and implanted Cu4O3 and CuO films were studied.

PL

W artykule opisana została metoda implantacji jonami Cr+ o energii 10 keV i 15 keV, która może być stosowana do modyfikacji cienkich warstw półprzewodnikowych. Wykonano symulacje procesu implantacji z wykorzystaniem programu Stopping and Range of Ions in Matter uwzględniając różne energie wiązki jonów. Przedstawiono schematy aparatury implantatora oraz układu do rozpylania magnetronowego cienkich warstw. Optyczne i strukturalne właściwości nieimplantowanych i zaimplantowanych warstw Cu4O3 i CuO zostały zbadane.

4

Hall effect test bench for temperature dependence of carrier concentration

Dyndał Katarzyna, Sobków Zbigniew, Sanetra Jerzy, Marszałek Konstanty W.

Przegląd Elektrotechniczny

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2022

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R. 98, nr 9

231--234

EN

This paper presents an integrated bench for Hall effect measurements consisting of a helium cryostat placed between the electromagnet poles with a field of 0.5 T and a control and measurement system, as well as control algorithm for different operating modes. The results of measurements of majority carrier concentration by van der Pauw method in the temperature range 165 K - 300 K for indium tin oxide (ITO).

PL

W artykule przedstawiono zintegrowane stanowisko do pomiaru efektu Hall’a składające się z helowego kriostatu umieszczonego między nabiegunnikami elektromagnesu o polu 0,5 T oraz systemu kontrolno-pomiarowego, a także algorytmu sterowania dla różnych modów pracy. Zaprezentowano wyniki pomiarów koncentracji nośników większościowych metodą van der Pauw’a w zakresie temperatur od 165 K do 300 K dla warstw tlenku indowo-cynowego (ITO).

5

Design of complex energy systems (thin film photovoltaics, collectors, heat pumps and energy storage)

Dyndał Katarzyna, Marszałek Konstanty W., Kąkol Zbigniew

Przegląd Elektrotechniczny

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2022

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R. 98, nr 9

243--246

EN

This paper presents a method for obtaining photovoltaic thin films and simulation results of complex power systems. Photovoltaic thin films were obtained using the magnetron sputtering method. Simulations of complex power systems consisting of thin photovoltaic modules, energy storage and a heat pump have been performed. The capabilities of one of the most powerful design software such as Vela Solaris Polysun software were presented by showing chosen the simulation results.

PL

W pracy przedstawiono metodę otrzymywania cienkich fotowoltaicznych warstw oraz wyniki symulacji złożonych systemów elektroenergetycznych. Cienkie warstwy fotowoltaiczne otrzymano za pomocą metody rozpylania magnetronowego. Wykonano symulację złożonych systemów energetycznych składających się z cienkowarstwowych modułów fotowoltaicznych, akumulatorów i pompy ciepła. Przedstawiono możliwości jednego z najbardziej zaawansowanych programów projektowych, jakim jest oprogramowanie Polysun firmy Vela Solaris na przykładzie wybranych wyników symulacji.

6

Badania wpływu grubości warstwy miedzi na efekt gigantycznego magnetooporu w cienkowarstwowych strukturach NiFe/Cu/NiFe

Kisała Jakub, Kociubiński Andrzej, Czarnacka Karolina, Gęca Mateusz, Duk Jakub

Przegląd Elektrotechniczny

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2022

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R. 98, nr 9

199--201

PL

W pracy opisane zostały podstawowe informacje dotyczące zjawiska gigantycznego magnetooporu, jak i struktur, w których zjawisko to jest obserwowalne. Przedstawiona została sekwencja technologiczna cienkich struktur NiFe/Cu/NiFe wykonanych metodą rozpylania magnetronowego. Dwie prezentowane serie struktur różnią się zastosowaną grubością warstwy niemagnetycznej miedzi wynoszącą 5 nm oraz 2,5 nm. Wykonane zostały pomiary rezystancji stałoprądowej struktur obu serii w stałym polu magnetycznym o wartości 0,5 T. Porównanie otrzymanych wyników pozwala stwierdzić, że zmiany rezystancji struktury w ramach zjawiska gigantycznego magnetooporu są większe dla przyrządu o mniejszej grubości warstwy miedzi.

EN

This paper describes the basic information about the phenomenon of giant magnetoresistance as well as the structures exhibiting in which this phenomenon is observable. The technological sequence of NiFe/Cu/NiFe thin structures fabricated by magnetron sputtering is presented. The two series of structures presented differ in the thickness of the non-magnetic copper layer used being 5 nm and at 2,5nm. Measurements of the DC resistance of the structures of both series in a constant magnetic field of 0.5 T were performed. Comparison of the obtained results allows us to conclude that the changes of the structure resistance under the giant magnetoresistance phenomenon are larger for smaller thickness of the copper layer.

7

Microstructural Studies of Ag/TiO2 Thin Film; Effect of Annealing Temperature

Kamrosni Abdul Razak, Dewi Suryani Che Halin, Azliza Azani, Mustafa A.B.A. Mohd, Anuar M.S. Mohd Arif, Norsuria Mahmed, Chobpattana Varistha, Kaczmarek L., Jeż Bartłomiej, Nabiałek Marcin

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

241--245

EN

Microstructures are an important link between materials processing and performance, and microstructure control is essential for any materials processing route where the microstructure plays a major role in determining the properties. In this work, silverdoped titanium dioxide (Ag/TiO2) thin film was prepared by the sol-gel method through the hydrolysis of titanium tetra-isopropoxide and silver nitrate solution. The sol was spin coated on ITO glass substrate to get uniform film followed by annealing process for 2 hours. The obtained films were annealed at different annealing temperatures in the range of 300°C-600°C in order to observe the effect on crystalline state, microstructures and optical properties of Ag/TiO2 thin film. The thin films were characterized by X-Ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectrophotometry. It is clearly seen, when the annealing temperature increases to 500°C, a peak at 2θ = 25.30° can be seen which refers to the structure of TiO2 tetragonal anatase. The structure of Ag/TiO2 thin film become denser, linked together, porous and uniformly distributed on the surface and displays the highest cut-off wavelength value which is 396 nm with the lowest band gap value, which is 3.10 eV.

8

Effect of Nanoindentation Rate on Plastic Deformation in Cu Thin Films

Chocyk Dariusz, Zientarski Tomasz

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 1

170--179

EN

The paper investigates the nanoindentation process with different rates in the Cu (001) of FCC system. The indentation process was done using molecular dynamics simulation based on the embedded atom method theory and Morse potential. Simulation process of indentation used a rigid spherical indenter with the diamond structure. To structure characterization we applied the adaptive common neighbour and the dislocation extraction analysis. It was found that the range of the linear change of the indentation force depends on the rate of response of the system. The initial range of the linear dependence of stress evolution also depends on the rate of indentation. Moreover, the average total normal stress in the system is only compressive. After linear changes, we observe oscillating changes in stress evolution. During indentation, for the range of linear changes of stress, dislocations aggregated only around the indenter surface. The creation of dislocations is directly connected with the structural changes. The structure analysis revealed the formation of HCP and BCC structure in the Cu (001) of FCC systems and a correlation with the creation of dislocations.

9

Sliding of spherical ball on solid lubricating coating combined with wear process

Białas Marcin, Maciejewski Jan, Kucharski Stanisław

Welding Technology Review

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2021

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R. 93, nr 1

39--50

EN

In present paper we show results of ball-on-disk wear experiment of MoS2 film deposited on Ti6Al4V substrate. The ball material is aluminium oxide. The tests are performed for different surrounding temperature conditions: 20°C, 200°C and 350°C. It is shown that depth of the wear groove increases with increasing surrounding temperature. A finite element modelling approach is next developed to mimic the experimental observations of ball-on-disk wear process. It is based on the assumption of steady state condition developed during short time scale at contact region. The steady state results can next be applied to long time scale in which wear process is numerically simulated. Model results are compared with experimentally obtained wear groove and show satisfactory agreement.

PL

Artykuł prezentuje wyniki testu zużycia powłoki samosmarującej MoS2 nałożonej na podłoże wykonane z materiału Ti6AI4V. Powłoka obciążona jest kulką szafirową w ruchu rotacyjnym. Badania wykonano w trzech różnych temperaturach otoczenia: 20°C, 200°C oraz 350°C. Wykazano, że głębokość rowka zużyciowego wzrasta wraz ze wzrostem temperatury otoczenia. Zaproponowano model metody elementów skończonych za pomocą którego zasymulowany został proces zużycia warstwy. Punktem wyjścia dla tej części pracy było założenie stanu ustalonego, powstającego w obszarze kontaktu pomiędzy kulą a warstwą. Warunki odpowiadające temu stanowi przyjęto do matematycznego opisu procesu zużycia z wykorzystaniem równań Archarda. Na zakończenie eksperymentalny profil zużycia porównany został z wynikami otrzymanymi metodą elementów skończonych.

10

Surface roughness and residual stress evolution in SiNx/SiO2 multilayer coatings deposited by reactive pulsed magnetron sputtering

Tien Chuen-Lin, Lee Po-Wei, Lin Shih-Chin, Lin Hong-Yi

Optica Applicata

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2021

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Vol. 51, nr 2

223--233

EN

The surface roughness and residual stress behavior in two types of SiNx/SiO2 dielectric quarter-wave stacks was investigated experimentally. A reactive pulsed magnetron sputtering system was used to prepare the SiNx/SiO2 multilayer thin films. The results show that SiNx/SiO2 quarter-wave stack with a buffer layer of MgF2 thin film can reduce the residual stress. The effect of aging on the residual stress in two quarter-wave stacks was also studied. We found that the residual stresses in both SiNx/SiO2 multilayer coatings are changed from a compressive state to a tensile stress state with increasing the aging time. The root mean square (RMS) surface roughness of MgF2/(SiNx/SiO2)22 and (SiNx/SiO2)22 quarter-wave stacks are 2.23 ± 0.22 nm and 2.08 ± 0.20 nm, respectively.

11

Refractive index and salinity sensors by gallium-doped zinc oxide thin film coated on side-polished fibers

Tien Chuen-Lin, Mao Hao-Sheng, Mao Tzu-Chi

Optica Applicata

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2021

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Vol. 51, nr 1

23--36

EN

This work presents a high-sensitivity refractive index and salinity sensor by using fiber-optic side-polishing and electron-beam evaporation techniques. Thin film coated on the flat surface of side-polished fibers can generate a lossy mode resonance (LMR) effect. A gallium-doped zinc oxide (GZO) thin film was prepared by an electron-beam evaporation with the ion assisted deposition method. The residual thickness of the side-polished fiber was 76.5 μm, and GZO film thickness of 69 nm was deposited on the flat surface of the side-polished fiber to fabricate LMR-based fiber sensors. The variation in the optical spectrum of LMR-based fiber sensors was measured by different refractive index saline solutions. The LMR wavelength shift is caused by the refractive index change, which is nearly proportional to the salinity. The corresponding sensitivity of the proposed fiber-optic sensor was 3059 nm/RIU (refractive index unit) for the refractive index range of 1.333 to 1.398. To evaluate the sensitivity of LMR salinity sensors, the saline solution salinities of 3.6%, 7.3%, 10.9%, 14.6%, 18.2% and 21.9% were measured in this work. The experimental result shows that the sensitivity of the proposed salinity sensor is 9.94 nm/%.

12

Nickel comb capacitors for real-time monitoring of cancer cell cultures

Kociubiński Andrzej, Zarzeczny Dawid

Przegląd Elektrotechniczny

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2020

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R. 96, nr 9

149--152

EN

The work is devoted to the technology of biocompatible substrates with nickel electrodes for in vitro impedance cell culture studies. The legitimacy of this subject was tested by conducting measurements using a system based on the Electric Cell-Substrate Impedance Sensor method. A device for cell bioimpedance testing, made in thin-film technology, has been described. Parameters and applications of the material used for construction, which is commonly used nickel, are discussed. The results of preliminary studies on melanoma cancer cells from the A375 cell line were presented, during which the already used measurement matrices were used. An analysis of the observed changes and obtained results was carried out.

PL

Praca poświęcona jest technologii biokompatybilnych podłoży z niklowymi elektrodami do badań impedancji hodowli komórek in vitro. Zasadność podjęcia tej tematyki przetestowano przeprowadzając pomiary przy użyciu systemu opartego na metodzie ECIS (ang. Electric CellSubstrate Impedance Sensor). Opisano przyrząd służący do badań bioimpedancji komórek, wykonany w technologii cienkowarstwowej. Omówiono parametry i zastosowania wykorzystanego do budowy urządzania materiału, którym jest powszechnie stosowany nikiel. Przedstawiono wyniki wstępnych badań nad komórkami nowotworowymi czerniaka z linii komórkowej A 375, do których użyto wykonane matryce pomiarowe. Dokonano analizy zaobserwowanych zmian i otrzymanych rezultatów.

13

The optical parameters of TiO2 antireflection coating prepared by atomic layer deposition method for photovoltaic application

Szindler Marek, Szindler Magdalena M.

Optica Applicata

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2020

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Vol. 50, nr 4

663--670

EN

Titanium dioxide thin films have been deposited on silicon wafers substrates by an atomic layer deposition (ALD) method. There optical parameters were investigated by spectroscopic ellipsometry and UV/VIS spectroscopy. A material with a refractive index of 2.41 was obtained. Additionally, in a wide spectral range it was possible to reduce the reflection from the silicon surface below 5%. The Raman spectroscopy method was used for structural characterization of anatase TiO2 thin films. Their uniformity and chemical composition are confirmed by a scanning electron microscope (SEM) energy dispersive spectrometer (EDS).

14

Real-time monitoring of cell cultures with nickel comb capacitors

Kociubiński Andrzej, Zarzeczny Dawid, Szypulski Maciej, Wilczyńska Aleksandra, Pigoń Dominika, Małecka-Massalska Teresa, Prendecka Monika

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2020

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T. 10, nr 2

32--35

EN

The aim of the study was to present a method for assessing the condition of cell culture by measuring the impedance of cells cultured in the presence of nickel. For this purpose, an impedance measurement technique using nickel comb capacitors was used. The capacitor electrodes were made using a thin film magnetron sputtering. In the experimental part, the culture of cells of mouse fibroblasts on the prepared substrate was performed. The cell culture lasted 43 hours and showed that the presented technique allows it to be used to analyze the effect of nickel on cells.

PL

Celem pracy było przedstawienie metody oceny stanu hodowli komórkowej poprzez pomiar impedancji komórek hodowanych w obecności niklu. W tym celu zastosowano technikę pomiaru impedancji z wykorzystaniem niklowych kondensatorów grzebieniowych. Cienkowarstwowe elektrody kondensatora wykonano metodą rozpylania magnetronowego. W części eksperymentalnej przeprowadzono hodowlę komórek mysich fibroblastów na przygotowanym podłożu. Hodowla komórkowa trwała 43 godziny i wykazała, że przedstawiona technika mogłaby być zastosowana do analizy wpływu niklu na komórki.

15

Determination of the structural state and stability of the laser crystallized Cd1-xМnxTe crystal surface

Strebezhev Victor, Yuriychuk Ivan, Fochuk Petro, Nichyi Sergiy, Dobrovolsky Yuriy, Tkachuk Victoria, Sorokatyi Mykola, Sorokatyi Yurii

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2020

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T. 10, nr 1

40--43

EN

The modified surface layers of the Cd1-xМnxTe crystals were obtained by the laser recrystallization of the crystal surface with the use of millisecond and nanosecond impulse ruby lasers. The determination and diagnostics of the layer structural state were performed by the study of the electron channeling patterns in the SEM. The AFM studies showed that mechanically stable contact regions within the CdTe crystal –Cu film system can be formed, depending on the laser energy density and beam defocusing. On the base of the ellipsometric studies, it was found that while irradiating the Cd1-xМnxTe crystal surface, the refractive index of the oxide film on the modified surface changes depending on the laser beam energy density, which can be interpreted as the formation of the oxides of the different chemical composition.

PL

Zmodyfikowane warstwy wierzchnie kryształów Cd1-xМnxTezostały uzyskane metodą laserowej rekrystalizacji powierzchni kryształu przy wykorzystaniu impulsów milisekundowychi nanosekundowychlaserów rubinowych. Określenie i diagnostyka strukturalnej postaci powierzchni zostały wykonane metodą badania struktury kanałów elektronu SEM. Badania AFM wykazały,że mogą zostać wytworzoneobszary mechanicznie stabilnego obszaru kontaktowego kryształ CdTe –powłoka Cu,w zależności od skupienia energii laserowejoraz zdekoncentrowania wiązki. Na podstawie pomiarów elipsometrycznychodkryto,że podczas napromieniowywania powierzchni kryształu Cd1-xМnxTe, wskaźnik refrakcyjny powłoki tlenku na powierzchni zmodyfikowanej ulega zmianie w zależności od skupienia energii wiązki laserowej, co może być interpretowane,jako powstawanie tlenków o różnym składzie chemicznym.

16

Wpływ struktury na właściwości elektryczne i optyczne cienkich warstw na bazie tlenków Ti i Hf

Obstarczyk Agata, Kaczmarek Danuta, Mazur Michał, Domaradzki Jarosław, Wojcieszak Damian

Przegląd Elektrotechniczny

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2019

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R. 95, nr 9

111--114

PL

Celem niniejszej pracy było wytworzenie nanokrystalicznych oraz amorficznych cienkich warstw na bazie mieszaniny tlenków Ti i Hf metodą rozpylania magnetronowego. W ramach pracy przeprowadzono również szczegółową analizę wpływu struktury wybranych warstw na ich właściwości elektryczne takie jak gęstość prądu upływu oraz względna przenikalność elektryczna, a także właściwości optyczne w tym współczynnik ekstynkcji światła.

EN

The aim of this work was to prepare nanocrystalline and amorphous thin films based on a mixture of Hf and Ti oxides by magnetron sputtering. As a part of work, the detailed analysis of the impact of the thin films structure on their electrical properties such as leakage current density and dielectric constant and optical properties like extinction coefficient was carried out.

17

Thin film characterization of Ce and Sn co-doped CdZnS by chemical bath deposition

Shrivastava Ritu, Shrivastava S. C.

Materials Science Poland

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2019

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Vol. 37, No. 4

577--584

EN

Cerium and tin co-doped cadmium zinc sulfide nanoparticles (CdZnS:Ce)Sn were synthesized by chemical bath deposition method with a fixed concentration of Ce (3.84 mol%) and three different concentrations of Sn (2 mol % and 4 mol% and 6 mol%). They showed broad photoluminescence spectra in the visible region under the ultraviolet excitation with a wavelength of 325 nm. The photoluminescence emission peaks were obtained at 540 nm, 560 nm and 570 nm for CdZnS, CdZnS:Ce and (CdZnS:Ce)Sn thin films, respectively having different concentrations of Sn. It has been observed that the photoluminescence emission peak shifted to higher wavelength region with an increase in intensity by Ce doping and Ce-Sn co-doping. Further enhancement in luminescence peak intensity has been observed by increasing concentration of Sn in (CdZnS:Ce)Sn films. Average crystallite size, measured from XRD data, was found to be increased with increasing concentration of Sn. An increase in the concentration of Sn shifted the UV-Vis absorption edge toward the higher wavelength side. Energy band gap for undoped CdZnS and Ce-Sn co-doped CdZnS varied from 2.608 eV to 2.405 eV. The SEM micrographs of CdZnS and (CdZnS:Ce)Sn films showed the leafy-like and ball-like structures. The presence of Sn and Ce was confirmed by EDAX analysis.

18

SHI irradiation induced modifications of plasmonic properties of Ag-TiO2 thin film and study using FDTD simulation

Sharma Himanshu, Singhal R.

Materials Science Poland

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2019

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Vol. 37, No. 3

373--380

EN

Modifications in morphological and plasmonic properties of heavily doped Ag-TiO2 nanocomposite thin films by ion irradiation have been observed. The Ag-TiO2 nanocomposite thin films were synthesized by RF co-sputtering and irradiated by 90 MeV Ni ions with different fluences. The modifications in morphological, structural and plasmonic properties of the nanocomposite thin films caused by ion irradiation were studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-Vis absorption spectroscopy. The thickness of the film and concentration of Ag were assessed by Rutheford backscattering (RBS) as ~50 nm and 56 at.%, respectively. Interestingly, localized surface plasmon resonance (LSPR) appeared at 566 nm in the thin film irradiated at the fluence of 1 × 1013 ions/cm2. This plasmonic behavior can be attributed to the increment in interparticle separation. Increased interparticle separation diminishes the plasmonic coupling between the nanoparticles and the LSPR appears in the visible region. The distribution of Ag nanoparticles obtained from HR-TEM images has been used to simulate absorption spectra and electric field distribution along Ag nanoparticles with the help of FDTD (Finite Difference Time Domain). Further, the ion irradiation results (experimental as well simulated) were compared with the annealed nanocomposite thin film and it was found that optical properties of heavily doped metal in the metal oxide matrix can be more improved by ion irradiation in comparison with thermal annealing.

19

Role of RF power on physical properties of RF magnetron sputtered GaN/p-Si(1 0 0) thin film

Mantarci Asim, Kundakçi Mutlu

Materials Science Poland

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2019

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Vol. 37, No. 3

454--464

EN

GaN thin films were deposited on p-Si(1 0 0) substrates using RF magnetron sputtering at various RF powers. Influence of RF power on morphological, optical and structural properties of GaN thin films were investigated and presented in detail. XRD results proved that the films were polycrystalline in structure with (1 0 0) and (1 1 0) planes of hexagonal GaN. It was found that increasing RF power led to deterioration of crystal structure of the films due to increased decomposition of GaN. Stress in GaN thin films was calculated from XRD measurements and the reasons for this stress were discussed. Furthermore, it was analyzed and interpreted whether the experimental measurement results support each other. E2 (high) optical phonon mode of hexagonal GaN was obtained from the analysis of Raman results. UV-Vis spectroscopy results showed that optical band gap of the films varied by changing RF power. The reasons of this variation were discussed. AFM study of the surfaces of the GaN thin films showed that some of them were grown in Stranski-Krastanov mode and others were grown in Frank-Van der Merwe mode. AFM measurements revealed almost homogeneous, nanostructured, low-roughness surface of the GaN thin films. SEM analysis evidenced agglomerations in some regions of surface of the films and their possible causes have been discussed. It has been inferred that morphological, optical, structural properties of GaN thin film can be changed by controlling RF power, making them a potential candidate for LED, solar cell, diode applications.

20

Controlling of optical band gap of the CdO films by zinc oxide

Kati Nida

Materials Science Poland

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2019

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Vol. 37, No. 1

136--141

EN

In this study, CdZnO films prepared at different ratios of dopants (CdO:ZnO = 5:5, CdO:ZnO = 6:4, and CdO:ZnO = 8:2) were coated on glass surface by using the sol-gel spin coating technique. After this process, surface structure and optical properties of the CdZnO films was investigated by atomic force microscopy (AFM) and UV-Vis spectroscopy. The surface structure of the CdZnO films depended on the content of ZnO and CdO in the films. Low percentage of CdO films were very similar to the ZnO film but higher amount of CdO resuted in granular structures together with pure structure of ZnO in the films. Eg values of produced CdZnOs depended on the additions of CdO and ZnO. The obtained Eg values of the produced CdO:ZnO = 5:5 (S3), CdO:ZnO = 6:4 (S4), and CdO:ZnO = 8:2 (S5) films are 2.5 eV, 2.49 eV, and 2.4 eV, respectively.