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1

Cost-effective titania layers over 100 nm thick : effect of annealing on the structural, morphological, and optical properties

Zięba Magdalena, Tyszkiewicz Cuma, Gondek Ewa, Wojtasik Katarzyna, Nizioł Jacek, Dorosz Dominik, Starzyk Bartłomiej, Szymczak Patryk, Pakieła Wojciech, Rogoziński Roman, Karasiński Paweł

Opto-Electronics Review

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2023

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Vol. 31, No. 4

art. no. e147913

EN

Titania dioxide (TiO₂) layers were synthesized via the acid-catalysed sol-gel route using titania (IV) ethoxide, and then annealed at temperatures varying in the range of 150-700 °C. The research concerned the effect of annealing temperature on the structure of TiO₂ layers, their surface morphology, and their optical properties. Further, X-ray diffractometry, and Raman spectroscopy were used to determine the structure of TiO₂ layers. Scanning electron and atomic force microscopy were used to study the surface morphology of TiO₂ layers. Transmittance, reflectance, absorption edge, and optical homogeneity were investigated by UV-VIS spectrophotometry, while the refractive index and thicknesses of TiO₂ layers were measured using a monochromatic ellipsometer. Chromatic dispersion characteristics of the complex refractive index were determined using spectroscopic ellipsometry. Structural studies have shown that the TiO₂ layers annealed at temperatures up to 300 °C are amorphous, while those annealed at temperatures exceeding 300 °C are polycrystalline containing only anatase nanocrystals with sizes increasing from 6 to 20 nm with the increase of the annealing temperature. Investigations on the surface morphology of TiO₂ layers have shown that the surface roughness increases with the increase in annealing temperature. Spectrophotometric investigations have shown that TiO₂ layers are homogeneous and the width of the indirect optical band gap varies with annealing temperature from 3.53 eV to 3.73 eV.

2

Structured Analysis of Nanostructured Zinc Oxide (ZnO) Thin Films Deposited by Sol-Gel

Hussin Rosniza, Hanafi F., Rashid R. A., Harun Z., Kamdi Z., Ibrahim S. A., Ainuddin A. R., Rahman W., Leman A. M.

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

1055--1060

EN

In this work, zinc oxide (ZnO) thin films are deposited on glass substrate using the sol-gel spin coating technique. The effect of annealing temperature on structural properties was investigated. The ZnO sol-gel was produced from zinc acetate dehydrate as the starting material with iso-propanol alcohol as the stabilizer. The ratio was controlled, distilled water and diethanolamine as the solvent mixing on a magnetic stirrer for an hour under constant heat of 60°C. The ZnO thin film was deposited using the spin coating technique with the speed of 3000 rpm for 30 minutes before the sample undergoes pre-heat in the oven at the temperature of 100°C for 10 minutes. The sample was annealing in the furnace for an hour at 200°C, 350°C, and 500°C. The X-ray diffraction (XRD) analysis confirms that hexagonal wurtzite structure with zincite and zinc acetate hydroxide hydrate composition. The thin films surface roughness was analyzed using an atomic force microscope (AFM) and scanning electron microscope (SEM) for surface morphology observation.

3

Electroless Nickel Plating on AM60B Magnesium Alloy via Ti-Zr/Sol-Gel Composite Layer as Pretreatment

Nazari Zhale, Seifzadeh Davod, Rajabalizadeh Zahra

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

913--920

EN

The Ti-Zr and Ti-Zr/sol-gel were used as pretreatment layers before the electroless nickel coating on AM60B magnesium alloy. Scanning Electron Microscopy was employed to investigate the surface morphology of the pretreated layers and applied electroless coatings. Chemical analysis of the Ti-Zr layer, and nickel coatings was done using the Energy-Dispersive X-ray Spectroscopy. Moreover, the X-ray Diffraction and Atomic Force Microscopy methods were utilized to evaluate the microstructure and surface roughness of the electroless coatings, respectively. Electrochemical Impedance Spectroscopy was employed to study the corrosion behavior of Ni-P coatings. The results show that Ti-Zr layer has structural cracks, and the sol-gel film was covered all cracks entirely. The cauliflower-like electroless nickel coating was applied on both mentioned pretreated layers. The cross-sectional images revealed the higher thickness for the electroless coating on Ti-Zr/sol-gel layer, probably due to a large number of Ni nucleation centers. The EIS results demonstrate that the electroless coating on Ti-Zr/sol-gel has high corrosion protection and microhardness value.

4

Pb-doped cuo thin films synthetized by sol-gel method

Tabli Dalila, Touka Nassim, Baddari Kamel, Selmi Nourddine

Advances in Materials Science

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2022

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Vol. 22, nr 3(73)

5--13

EN

The physical properties of pure CuO and Pb doped CuO thin films, deposited on glass substrates by a sol-gel method, were investigated. Structural analysis revealed the polycrystalline nature of the pure CuO and Pb:CuO composite films with a monoclinic structure, the crystallite size decreased and ranged from 36.78 nm to around 21.5 nm. The SEM images of the CuO thin films showed that the Pb doping concentration affects the surface morphology of the Pb:CuO composites. The absorbance of the Pb:CuO composites is higher than that of the undoped CuO thin films. The optical band gap energies of undoped CuO and Pb doped CuO thin films were estimated to 1.9 (pure), 2.17(5%) and 2.74 (7%)eV, and found that the band gap energy (Eg) increases with the Pb concentration. This blue shift is due to the quantum confinement induced by the reduction in the size of the crystallites.

5

Mesoporous magnesium oxide xerogels : synthesis and structural characteristics

Malinowski Janusz, Pudło Wojciech

Prace Naukowe Instytutu Inżynierii Chemicznej Polskiej Akademii Nauk

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2021

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nr 25

33--43

EN

The paper presents the results of a study on the synthesis of magnesium oxide xerogels. In the synthesis, the sol-gel method was used, in which magnesium methoxide was applied as a magnesium precursor. The obtained magnesium hydroxide was subjected to the thermal dehydration process to obtain magnesium oxide particles. The influence of xylene addition during magnesium methoxide hydrolysis on the structure of the magnesium hydroxide and oxide was investigated.

PL

W pracy przedstawiono wyniki badań nad syntezą cząstek kserożeli tlenku magnezu. W procesie syntezy zastosowano metodę zol-żel, w której wykorzystano metanolan magnezu jako prekursor tlenku magnezu. Otrzymany wodorotlenek magnezu poddano procesowi termicznej dehydratacji w celu otrzymania tlenku magnezu. Zbadano wpływ dodatku ksylenu na strukturę wodorotlenku i tlenku magnezu.

6

Perspective of sol-gel hydrophobic silica deposited using low-pressure cold spray and ultrasonic atomizing for automotive coatings

Gibas Anna, Gąsiorek Jolanta

Journal of TransLogistics

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2021

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Vol. 7, nr 1

113--128

EN

The automotive sector is under constant pressure to minimize fuel consumption and reduce pollution emissions while maintaining a declining tendency for weight and cost reduction. This makes the material selection process a major of engineering design considerations. In the paper, the main automotive requirements were formulated to analyze the potential of selected deposition (low pressure cold spray and ultrasonic atomizing) and material fabrication (sol-gel method) techniques for application in the automotive industry.

PL

Sektor motoryzacyjny znajduje się pod ciągłą presją, aby minimalizować zużycie paliwa i redukować emisję zanieczyszczeń przy jednoczesnym utrzymaniu dotychczasowego tempa redukcji masy i kosztów. To sprawia, że dobór materiału jest szczególnie ważny podczas procesu projektowania wybranego elementu. W artykule sformułowano główne wymagania branży automotive do analizy potencjału wybranych technik osadzania (niskociśnieniowego natryskiwania na zimno i atomizacji ultradźwiękowej) oraz wytwarzania materiału (metoda zol-żel) do zastosowań jako powłoki ochronne w przemyśle samochodowym.

7

Preparation and Characterization of ZnO-Zeolite Nanocomposite for Photocatalytic Degradation by Ultraviolet Light

Gayatri Rianyza, Agustina Tuty Emilia, Bahrin David, Moeksin Rosdiana, Gustini Gustini

Journal of Ecological Engineering

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2021

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Vol. 22, nr 2

178--186

EN

The increasing growth of the textile industry does not only provide benefits in the economic sector but also has the potential to damage the environment, because it generates the dye wastewater which is hard to eliminate. Procion red is one of the synthetic textile dyes that is toxic to the aquatic environment and it needs to be processed properly. The photocatalytic method of processing dye wastewater is the most effective, because it can remove the harmful pollutants in the dye wastewater. This study aimed to prepare and characterize the ZnO-Zeolite nanocomposites for photocatalytic applications tested with a 50 mg/L procion red dye sample. The nanocomposites consisted of the ZnO semiconductors and synthetic zeolite adsorbents prepared by using the sol-gel method. The dye degradation test was carried out under the irradiation conditions with ultraviolet (UV) lamp. Apart from the ZnO-Zeolite nanocomposite, testing was also carried out with the synthetic zeolite and ZnO. The results of SEM-EDX and XRD characterization proved that the nanocomposite forming components were ZnO and zeolite and could be seen from the resulting peaks. BET showed that the surface area value of the ZnO-Zeolite nanocomposite increased to 95.98 m2/g, the pore size of the ZnO-Zeolite nanocomposite was 4.42 nm, and the total pore volume was 0.08 cm3/g. The obtained average crystalline size of ZnO-Zeolite nanocomposite was 32.87 nm. The percentage of dye degradation using the ZnO-Zeolite nanocomposite for 120 minutes has reached 90.42%.

8

TiO2 waveguides thin films prepared by sol-gel method on glass substrates with and without ZnO underlayer

Bouachiba Y., Taabouche A., Bouabellou A., Hanini F., Sedrati C., Merabti H.

Materials Science Poland

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2020

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Vol. 38, No. 3

381--385

EN

TiO2 thin films have been deposited on glass substrates with and without ZnO underlayer by sol-gel dip coating process. XRD patterns show the formation of anatase phase with the diffraction lines (1 0 1) and (2 0 0) in TiO2 /glass sample. In TiO2 /(ZnO/glass) sample, TiO2 is composed of anatase phase with the diffraction line (2 0 0) but the diffraction peaks of ZnO wurtzite are also well-defined. The determination of the refractive index and the thickness of the waveguiding layers has been performed by m-lines spectroscopy. The thickness of TiO2 thin films deduced by Rutheford Backscattering Geometry (RBS) agrees well with that obtained by m-lines spectroscopy. TiO2 /glass sample exhibits one guided TE0 and TM0 polarized modes. In TiO2 /(ZnO/glass) sample, only, TE0 single mode has been excited due to cutoff condition.

9

Synthesis and characterization of Li2MnO3 nanoparticles using sol-gel technique for lithium ion battery

Chennakrishnan Sandhiya, Thangamuthu Venkatachalam, Subramaniyam Akshaya, Venkatachalam Viknesh, Venugopal Manikandan, Marudhan Raju

Materials Science Poland

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2020

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Vol. 38, No. 2

312--319

EN

Nanoparticles of Li2MnO3 were fabricated by sol-gel method using precursors of lithium acetate and manganese acetate, and citric acid as chelating agent in the stoichiometric ratio. TGA/DTA measurements of the sample in the regions of 30 °C to 176 °C, 176 °C to 422 °C and 422 °C to 462 °C were taken to identify the decomposition temperature and weight loss. The XRD analysis of the sample indicates that the synthesized material is monoclinic crystalline in nature and the calculated lattice parameters are 4.928 Å (a), 8.533 Å (b), and 9.604 Å (c). The surface morphology, particle size and elemental analysis of the samples were observed using SEM and EDAX techniques and the results confirmed the agglomeration of nanoparticles and, as expected, Li2MnO3 composition. Half cells of Li2MnO3 were assembled and tested at C/10 rate and the maximum capacity of 27 mAh/g was obtained. Charging and discharging processes that occurred at 3 V and 4 V were clearly observed from the cyclic voltammetric experiments. Stability of the electrodes was confirmed by the perfect reversibility of the anodic and cathodic peak positions observed in the cyclic voltammogram of the sample. The Li2MnO3 nanoparticles exhibit excellent properties and they are suitable for cathode materials in lithium ion batteries.

10

Structural and optical studies of TiO2:Ag2O nanocomposite by sol-gel method

Koutu Vaibhav, Dhakar Rajesh, Ojha Pragya, Shastri Lokesh, Malik M. M.

Materials Science Poland

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2020

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Vol. 38, No. 2

263--270

EN

As TiO2 is suitable for electronic and electrical applications, in the present work the authors have successfully modified TiO2 by adding silver (Ag) to form titanium oxide-silver oxide (TiO2:Ag2O) nanocomposite samples by using sol-gel technique. Characterizations of these composites have been performed using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV-Vis spectroscopy. XRD study revealed that the crystal structure of the samples consisted of tetragonal and cubic phases. This study further showed an increment in the average crystallite size from 8 nm to 38 nm with an increase in Ag concentration. The increase in crystallite size has been confirmed additionally by SEM and AFM. The increment in the average particle size of the samples may be attributed to an increase in silver molarity in the TiO2 matrix. Significant red shift in the absorption edge has been observed, causing reduction in the energy bandgap of the composites from 3.89 eV to 3.46 eV with an increase in particle size which is evident from UV-Vis spectroscopic studies. This wide-band gap properties of the TiO2:Ag2O nanocomposite make it suitable for memory-storage devices and dielectric applications.

11

Structural and optical properties of ZnO thin film prepared by sol-gel spin coating

Balakrishnan G., Sinha Vivek, Peethala Yogesh Palai, Kumar Manoj, Nimal R. J. Golden Renjith, Hussain J. Hameed, Batoo Khalid Mujasam, Raslan Emad H.

Materials Science Poland

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2020

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Vol. 38, No. 1

17--22

EN

Zinc oxide (ZnO) thin films were deposited on Si (1 0 0) and glass substrates by sol-gel spin coating technique. Zinc acetate dihydrate, monoethanolamine and isopropanol were used as the sources for precursor solution and the resulting gel was used for the preparation of ZnO thin films. The films were annealed at different temperatures (100 °C to 500 °C) and the effect of annealing on the structural and optical properties was investigated. X-ray diffraction (XRD) and UV-Vis spectroscopy were used for the analysis of the films. The XRD results indicated the polycrystalline hexagonal structure of the ZnO films with (0 0 2) orientation. The optical properties of the films were studied using UV-Vis spectrophotometer in the wavelength range of 190 – 1100 nm. The optical characterization of the ZnO thin films showed the high transmittance of ~90 % for the films annealed at 400 °C. The films showed the absorbance ~360 – 390 nm and bandgap values of 3.40 – 3.10 eV, depending on the annealing temperature of the films.

12

Effect of titanium source and sol-gel TiO2 thin film formation parameters on its morphology and photocatalytic activity

Dulian Piotr, Zajic Jan, Żukowski Witold

Materials Science Poland

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2020

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Vol. 38, No. 3

424--433

EN

TiO2 thin films with different surface structure have been prepared from alkoxide solutions by the sol-gel method using different cationic precursors and heat treatment techniques. The effect of using titanium isopropoxide as well as titanium butoxide as a titanium source on the surface structure and photocatalytic activity of the resultant thin films was studied. Significant differences in the rate of hydrolysis and condensation reactions during the sol-gel synthesis were observed for these titanium precursors. This had a direct influence on the morphology of the as-prepared TiO2 films. Higher quality oxide coatings were obtained from titanium isopropoxide. They were characterized by a smaller grain size, improved surface roughness and uniform coverage of the glass substrate. A beneficial effect of calcination process after each sol application cycle in contrast to single step calcination after all dip-coating cycles was observed. Photocatalytic degradation tests showed that methyl orange was decolorized in the presence of all prepared TiO2 films by exposing their aqueous solutions to UV light (λ = 254 nm). The highest photocatalytic activity had the TiO2 layer produced using titanium isopropoxide.

13

Effect of coating steps on uniformity and gas permeability of mesoporous layers in ceramic membranes

Pakdehi Shahram G., Rahimi Elham, Shafiei Korosh

Materials Science Poland

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2020

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Vol. 38, No. 4

535--544

EN

Porous silica, silica-cobalt, silica-zirconia and zirconia membranes were synthesized by the sol-gel method. Multi-step coating (two, six, and ten steps) was used to reduce the defectiveness of the mesoporous layer. Scanning electron microscopy (SEM) images indicated that an increase in the number of coating steps improved the mesoporous layer quality. The results obtained from gas permeability tests with nitrogen and argon, however, indicated a reduction in the gas permeability with increasing coating steps. The reduction in gas permeability from two to six coating steps was more pronounced than from six- to ten- coating steps. It was found that six-step coating was economically justified in obtaining a uniform mesoporous layer. The results of pore radius calculations by Knudsen flow mechanism revealed that the pores in the silica, silica-cobalt, and zirconia membranes were in the mesoporous range. The sols with a mean particle size more than 100 nm are not recommended for synthesis of mesoporous layer free of defects. Furthermore, the type of acid used as a catalyst is also important in obtaining a layer without defectiveness.

14

Warstwy dielektryczne wytwarzane metodą zol-żel i techniką dip-coating do zastosowań w optoelektronice

Karasiński Paweł

Przegląd Elektrotechniczny

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2019

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R. 95, nr 9

161--164

PL

Metoda zol-żel jest chemicznym sposobem wytwarzania materiałów z fazy ciekłej. W artykule przedstawione są osiągnięcia autora w zakresie wytwarzania metodą zol-żel i techniką dip-coating dwuskładnikowych SiO2:TiO2 warstw falowodowych, warstw ditlenku krzemu oraz warstw ditlenku tytanu. Opracowane warstwy dielektryczne pokrywają zakres współczynnika załamania od 1,2 do 2,3. Opracowane warstwy falowodowe są podstawą rozwoju układów optyki zintegrowanej na zakres Vis-NIR do zastosowań sensorowych. Warstwy ditlenku krzemu i ditlenku tytanu wykorzystywane były do wytwarzania zwierciadeł dielektrycznych i pokryć antyrefleksyjnych. W pracy przedstawiane są wyniki analiz teoretycznych, charakterystyki technologiczne i wybrane wyniki badań wytwarzanych struktur.

EN

Sol-gel method is a chemical process used to fabricate materials from a liquid phase. This work presents the author's accomplishments in the field of fabrication two-compound SiO2:TiO2 waveguide films, silica as well as titania layers fabricated via the sol-gel method and dip-coating technique. Developed dielectric layers cover refractive indices from 1.2 to 2.3. Elaborated waveguide films are the basis for the development of integrated optic circuits over the VIS-NIR spectral range. Silicon dioxide layers, as well as titanium dioxide layers, were used to fabricate dielectric mirrors and anti-reflective coatings. This work presents the results of the theoretical analysis, technological characteristics and some of the author's experimental results of fabricated structures.

15

Effects of Al doping on defect behaviors of ZnO thin film as a photocatalyst

Yu Fucheng, Hu Hailong, Wang Bolong, Li Haishan, Song Tianyun, Xu Boyu, He Ling, Wang Shu, Duan Hongyan

Materials Science Poland

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2019

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Vol. 37, No. 3

437--445

EN

Al doped ZnO (AZO) thin films were prepared on silica substrates by sol-gel method. The films showed a hexagonal wurtzite structure with a preferred orientation along c-axis. Suitable Al doping dramatically improved the crystal quality compared to the undoped ZnO films. Dependent on the Al dopant concentration, the diffraction peak of (0 0 2) plane in XRD spectra showed at first right-shifting and then left-shifting, which was attributed to the change in defect concentration induced by the Al dopant. Photocatalytic properties of the AZO film were characterized by degradation of methyl orange (MO) under simulated solar light. The transmittance of the films was enhanced by the Al doping, and the maximum transmittance of 80 % in the visible region was observed in the sample with Al concentration of 1.5 at.% (mole fraction). The film with 1.5 at.% Al doping achieved also maximum photocatalytic activity of 68.6 % under solar light. The changes in the film parameters can be attributed to the variation in defect concentration induced by different Al doping content.

16

Dielectric properties of Bi-substituted LDHs synthesized by co-precipitation and sol-gel methods

Sokol Denis, Ivanov Maksim, Salak Andrei N., Grigalaitis Robertas, Banys Juras, Kareiva Aivaras

Materials Science Poland

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2019

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Vol. 37, No. 2

190--195

EN

Magnesium-aluminum-bismuth layered double hydroxides (Mg3Al1-xBix; LDHs) were prepared using both coprecipitation and sol-gel methods. For the preparation of Mg/Al/Bi LDH by the co-precipitation method, the appropriate amounts of dissolved starting materials (Al(NO3)3·9H2O, Mg(NO3)2·6H2O and Bi(NO3)3·5H2O) were mixed with a solution of NaHCO3:NaOH. In the sol-gel processing, the precursor Mg–Al–Bi–O gels were synthesized using the same starting materials and ethylene glycol as complexing agent. The mixed-metal oxides obtained by subsequent heating of Mg–Al–Bi–O gels at 650 °C were reconstructed to Mg3Al1-xBix LDHs in water at 80 °C. All the synthesized products were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and dielectric measurements.

17

Development of sol-gel derived gahnite anti-reflection coating for augmenting the power conversion efficiency of polycrystalline silicon solar cells

Kaliyannan Gobinath Velu, Palanisamy Senthil Velmurugan, Palanisamy Manivasakan, Subramanian Mohankumar, Paramasivam Prabhakaran, Rathanasamy Rajasekar

Materials Science Poland

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2019

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Vol. 37, No. 3

465--472

EN

The present research is focused on developing ZnAl2O4 (gahnite) spinel as an antireflection coating material for enhanced energy conversion of polycrystalline silicon solar cells (PSSC). ZnAl2O4 has been synthesized using dual precursors, namely aluminum nitrate nonahydrate and zinc nitrate hexahydrate in ethanol media. Diethanolamine has been used as a sol stabilizer in sol-gel process for ZnAl2O4 nanosheet fabrication. nanosheet was deposited layer-by-layer (LBL) on PSSC by spin coating method. The effect of ZnAl2O4 coating on the physical, electrical, optical properties and temperature distribution in PSSC was investigated. The synthesized antireflection coating (ARC) material bears gahnite (ZnAl2O4) spinel crystal structure composed of two dimensional (2D) nanosheets. An increase in layer thickness proves the LBL deposition of ARC on the PSSC substrate. The ZnAl2O4 2D nanosheet comprising ARC on the PSSC was tested and it exhibited a maximum of 93 % transmittance, short-circuit photocurrent of 42.364 mA/cm2 and maximum power conversion efficiency (PCE) 23.42 % at a low cell temperature (50.2 °C) for three-layer ARC, while the reference cell exhibited 33.518 mA/cm2, 15.74 % and 59.1 °C, respectively. Based on the results, ZnAl2O4 2D nanosheets have been proven as an appropriate ARC material for increasing the PCE of PSSC.

18

Nanoproszki na bazie TiO₂ do wytwarzania powłok samoczyszczących

Mańkowska Ewa, Kaczmarek Danuta, Obstarczyk Agata, Maciej Strzyżewski

Elektronika : konstrukcje, technologie, zastosowania

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2019

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Vol. 60, nr 7

24--26

PL

W pracy zaprezentowano wyniki badania wpływu ilości domieszki (2% at. oraz 4% at.) oraz temperatury wygrzewania (300°C i 600°C) na zdolność do rozkładu oranżu metylowego przez nanocząstki dwutlenku tytanu domieszkowane cerem (TiO₂:Ce) w wyniku procesu fotokatalizy. Nanocząstki TiO₂ zostały wytworzone metodą zol-żel, przy użyciu TTiP jako prekursora. Zaobserwowano, że lepsze właściwości fotokatalityczne ma próbka domieszkowana mniejszą ilością ceru, co oznacza, że istnieje optymalna zawartość domieszki. Aktywność fotokatalityczna tej próbki wynosiła 16,7%. Wygrzewanie w wysokiej temperaturze miało negatywny wpływ na zdolności próbek do rozkładu barwnika, gdyż aktywność fotokatalityczna żadnej z wygrzanych próbek nie przekroczyła 4%.

EN

This paper presents the results of the investigation of concentration of the dopant (2 at.% Ce and 4 at.% Ce) and high-temperature annealing (300°C i 600°C) on the decomposition of methyl orange by titanium dioxide nanoparticles doped with cerium (TiO₂:Ce) as a result of photocatalysis process. Methyl orange was decomposed by TiO₂:Ce nanoparticles, which were synthesized by sol-gel technique with using TTiP as a precursor. It was observed that the higher photocatalytic activity has been obtained by TiO₂ doped with smaller amount of cerium, which suggests the existence of the optimum dopant concentration. The photocatalytic activity of this nanoparticles was equal to 16.7%. Moreover, high-temperature annealing had a negative effect on TiO₂:Ce nanoparticles on decomposition ability, due to the fact that the photocatalytic activity of all annealed nanoparticles did not achieve 4%.

19

Titanium dioxide nanoparticles and thin films deposited by an atomization method

Machalska G., Noworolnik M., Szindler M., Sitek W., Babilas R.

Archives of Materials Science and Engineering

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2019

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Vol. 100, nr 1/2

34--41

EN

Purpose: The article presents the results of research on titanium dioxide synthesized by a sol-gel method that is an easy process enabling the control of the shape and size of particles The purpose of this article is to examine titanium dioxide nanoparticles and thin films deposited by an atomization method. Design/methodology/approach: Titanium dioxide sol was synthesized by using titanium isopropoxide as a precursor. Optical properties were measured by a UV-Vis spectrometer. Structural studies were performed by Raman spectroscopy. Qualitative analysis was performed by the EDS. Surface morphology of nanoparticles and thin films was performed by the SEM technique. Findings: The sol-gel method allows the formation of uniform nanoparticles and thin films of titanium dioxide. The atomization method is a successful method for the deposition of sol to the surface of substrates. Research limitations/implications: The next step in the research will be to investigate the obtained thin films in dye-sensitized solar cells as a semiconductive layer. Practical implications: Unique properties of produced titanium dioxide nanostructural materials have caused the interest in them in such fields as optoelectronics, photovoltaics, medicine and decorative coatings. Originality/value: Titanium dioxide thin films and nanoparticles were synthesized using the sol-gel method and then deposited by the atomization method.

20

Sol-gel derived CdS nanocrystalline thin films: optical and photoconduction properties

Khan Z. R., Munirah, Aziz A., Khan M. S.

Materials Science Poland

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2018

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Vol. 36, No. 2

235--241

EN

High-quality CdS nanocrystalline thin films were grown by sol-gel spin coating method at different solution temperatures on glass substrates. As-deposited films exhibited nanocrystalline phase with hexagonal wurtzite structure and showed good adhesion and smooth surface morphology. It was clearly observed that the crystallinity of the thin films improved with the increase in solution temperature. Crystallites sizes of the films also increased and were found to be in the range of 10 mm to 17 nm. The influence of the growth mechanism on the band and sub-band gap absorption of the films was investigated using UV-Vis and photothermal deflection spectroscopy (PDS). The band gap values were calculated in the range of 2.52 eV to 2.75 eV. The band gap decreased up to 9 % with the increase in solution temperature from 45 °C to 75 °C. Absorption coefficients estimated by PDS signal showed the significant absorption in low photon energy region of 1.5 eV to 2.0 eV. The dark and illuminated I-V characteristics revealed that the films were highly photosensitive. The results demonstrated the potential applications of sol-gel grown CdS nanocrystalline thin films as photoconductors and optical switches.