Особенности магнетронного напыления тонких пленок оксида никеля для применения в составе перовскитных солнечных элементов

Use of inorganic oxides as transport layer material is a promising way to increase the efficiency of perovskite solar cells. Results of the studies of the influence of the gas mix composition in the plasma discharge used during magnetron sputtering on the optical, electrical, and structural parameters of deposited thin nickel oxide films are reported. Addition of oxygen or nitrogen to pure argon atmosphere (up to 30 vol %) was shown to change the growth rate (1.2–2.3 nm/min), resistivity of the samples (8.5–208 Ω cm), material band gap (2.85–3.43 eV), and the spectral dependence of the extinction coefficient, while the structural and morphological parameters of synthesized thin films were not affected. The lowest extinction coefficients were found in films deposited in pure argon atmosphere, which determines the capabilities of their usage in photovoltaic converters based on perovskite compounds.

Структурные и магнитные характеристики однослойных и многослойных наногранулированных пленок Co-Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-, полученных методом твердофазного синтеза

The results of structural and magnetic investigations of nanogranular Co–Al_2O_3 films formed from Co_3O_4/Al thin-film layered structures upon vacuum annealing are reported. The Co_3O_4/Al films have been obtained by sequential reactive magnetron sputtering of a metallic cobalt target in a medium consisting of the Ar + O_2 gas mixture and magnetron sputtering of an aluminum target in the pure argon atmosphere. It is shown that such a technique makes it possible to obtain nanogranular Co–Al_2O_3 single- and multilayer thin films with a well-controlled size of magnetic grains and their distribution over the film thickness.

Luminescence Properties of Europium Ion Doped Barium Borophosphate Phosphor

A series of BaBPO5phosphors doped with different concentration of Eu2+ions were synthesized by solid state reaction method. The reduction of Eu3+to Eu2+ions were obtained by heating in pure argon atmosphere. The structural properties were analyzed by using X-ray diffraction (XRD). Luminescence properties were measured at room temperature using photoluminescence (PL) spectroscopy and the effects of europium ion in the phosphor were investigated. The XRD results showed that crystal structure of the phosphor is hexagonal single phases. The addition of europium ions exhibit a broad emission band in the violet region peaking at 383 nm corresponding to transition of configuration state 4f65d à 4f7(8S7/2) of Eu2+ions. The emission intensity is affected by the concentration of Eu2+. The optimum intensity is observed for 0.2 mol % of Eu2+ion. The occurrence of emission lines in violet region indicates that this phosphor has potential in solid-state lighting application.

Spectroscopic Investigation of V3+:YAG Crystal

V3+ions doped YAG crystals were grown using the Czochralski method in a highly pure argon atmosphere. The transmission spectrum of trivalent vanadium in YAG crystal has been measured at room temperature. Eight bands were observed in which two bands centered at 690nm (14493cm-1) and 1490nm (6711cm-1) are reported for the first time. By using the crystal-field theory and introducing the average covalent factor model, we also presented the theoretical calculations of the energy level splitting of tetrahedrally coordinated V3+impurity systems in YAG crystal. These calculation results are in good agreement with the optical experiment data.

Dephosphorization Ability Estimation of FetO-Rich Demanganization Slag during Hot Metal Pre-Treatment

In order to find out the optimum thermodynamic conditions for hot metal dephosphorization and predict phosphorus content after demanganization pretreatment, thermodynamic equilibrium experiments between CaO-FetO-SiO2-MnO-P2O5 slag and silver/solid iron were carried out in an iron crucible at different temperature under pure argon atmosphere in an electric resistant furnace. The results indicate that phosphorus distribution ratios increase with an increase of basicity in the slag at the experiment temperature, and then they decrease with an increase of basicity at 1573K and 1623K. The phosphorus distribution ratios decrease with an increase of FetO content in the slag at 1573K, while they increase with an increase of FetO content in the slag and then decrease with an increase of FetO content in the slag at 1623K. The results indicate that the maximum phosphorus distribution ratio between slag and hot metal is 92.4 when basicity of the slag is 1.7 and FetO content in slag is 49.75 mass% at 1623K, and the correspondent phosphorus content in the carbon saturated iron is 0.019mass%. Dephosphorization is easier under low temperature. The equilibrium quotient of phosphorus obtained in the present work is formulated as a function of slag compositions and temperature using the multiple regression method which is used to predict phosphorus content equilibrium with the demanganization slag and optimum conditions needed for ideal phosphorus contents in demanganization pretreatment.

The Effect of Nano-Particles in Superconducting MgB2 Thin Films on Stainless Steel Substrates

We have fabricated several superconducting MgB2thin films on stainless steel substrates by using hybrid physical-chemical vapor deposition (HPCVD) in pure argon atmosphere. These films were observed by scanning electron microscopes (SEM) and used the energy dispersive X-ray spectroscopy (EDX) to make elements analyses. The film thickness is about 800~1000 nm. There were some cracks on the film surface when the film is bent by different angle. The number of cracks and their width increased with the increasing bending angle. Nevertheless, the films were attached to the substrates firmly. It concludes that the superconducting MgB2thin films have great ductility and adhesion to the stainless steel substrates. We found in these films many granules about tens of nanometers in size. These nano-granules can balance both the inner structure and the surface activity of the MgB2crystal. This might be an important reason for the ductility observed with the superconducting thin films. The exact explanation depends on further research.

Effect of R.F Power to the Properties of ZnO Thin Films Deposited by Magnetron Sputtering

The effect of radio frequency (R.F) power to the properties of zinc oxide (ZnO) thin films deposited by magnetron sputtering is presented. This project has been focused on electrical, optical and structural properties of ZnO thin films. The effect of variation R.F power at 100 watt ~ 400 watt on the ZnO thin films has been investigated. The thin films were examined using current-voltage (I-V) measurement, UV-Vis-NIR spectrophotometer, x-ray diffraction (XRD) and atomic force microscope (AFM). ZnO thin films were prepared at room temperature in pure argon atmosphere by a R.F magnetron sputtering using ZnO target. I-V measurement indicates that at 300 watt R.F power show the highest conductivity. All films have showed high UV absorption properties using UV-VIS spectrophotometer (JASCO 670). Highly oriented ZnO thin films [002] direction was obtained by using Rigaku Ultima IV. The root means square (rms) roughness for ZnO thin film were about (<2nm) was measured using AFM (Park System XE-100). Keywords-ZnO thin films, R.F power, electrical properties, optical properties, structural properties