Effect Of Deposition Temperature Research Articles

Effect of deposition temperature on the corrosion behavior of CVD SiC coatings on SiCf/SiC composites under simulated PWR conditions

To improve the hydrothermal corrosion resistance of SiCf/SiC composites, SiC coatings were chemical vapor deposited at 1000, 1150 and 1200 °C. Their corrosion behaviors were investigated using immersion tests and various analytical methods. The intergranular corrosion phenomenon was observed at all three coatings. It caused the delamination on the surface of 1000 and 1150 °C coatings, whereas only the local fall-off of large grains occurred on the 1200 °C coating. The large grain size and high crystallinity of coating deposited at 1200 °C contributed to the excellent corrosion resistance compared with coatings deposited at other two temperatures.

The impact of deposition and annealing temperature on the growth properties and surface passivation of silicon dioxide films obtained by atomic layer deposition

This paper studies the impact of deposition and annealing temperature on the growth properties and surface passivation of silicon dioxide (SiO2) films obtained by atomic layer deposition (ALD) using tris(dimethylamino)-silane (TDMAS) precursor. Increasing in deposition temperature from 200 to 350 °C alters the growth rate and refractive index significantly. The ALD-SiO2 films deposited at over 250 °C obtain excellent surface passivation after annealing at 650 °C, which could be explained by the synergistic effects of chemical and field-effect passivation caused by low interface defect states density (Dit) and high positive fixed charges density (Qf), respectively. Meanwhile, the effect of deposition temperature on surface passivation depends on the extent of TDMAS chemical adsorption and dissociation during ALD. X-ray photoelectron spectroscopy (XPS) shows low temperature as-deposited SiO2 films contain higher carbon impurities because of the remained dimethylamine groups. Regarding the impact of annealing temperature on surface passivation, secondary ion mass spectroscopy profiles and XPS results reveal that high-temperature annealing probably forms more hydrogen and oxygen vacancies at SiO2/Si interface, causing a decrease in Dit and an increase in positive Qf, respectively. This work provides a reference for applying ALD-SiO2 films to surface passivation technology of crystalline silicon solar cells.

AlN PEALD with TMA and forming gas: study of plasma reaction mechanisms.

The effect of deposition temperature and plasma dose on plasma-enhanced atomic layer deposition (PEALD) of AlN thin films with forming gas plasma and trimethylaluminum (TMA) has been studied. The temperature has a strong effect on TMA absorption considering the d-TMA absorptions at low deposition temperatures. The plasma effect on AlN growth was studied in terms of three aspects: (1) plasma effect on TMA absorption, (2) plasma effect on the insertion of plasma species and creation of chemical bonds with absorbed surface species, (3) plasma effect on the removal of organic ligands and weakly-bonded surface species. Plasma over-dosing and under-dosing not only affect the film growth rate but also the AlN film properties. A three-effect mathematical model of the plasma effect was built based on the three plasma effects, which is consistent with the AlN experimental growth results. The FTIR and dielectric studies of the PEALD AlN films support the model.

Effect of Deposition Temperature on the High-Temperature Corrosion Resistance of CrMoNbZr Coatings for High-Entropy Alloys

Effect of Deposition Temperature on the High-Temperature Corrosion Resistance of CrMoNbZr Coatings for High-Entropy Alloys

Effect of Deposition Temperature on the High-Temperature Corrosion Resistance of CrMoNbZr Coatings for High-Entropy Alloys

Effect of Deposition Temperature on the High-Temperature Corrosion Resistance of CrMoNbZr Coatings for High-Entropy Alloys

Plasma-Sprayed High-Performance (Bi2O3)0.75(Y2O3)0.25 Electrolyte for Intermediate-Temperature Solid Oxide Fuel Cells (IT-SOFCs).

Rare earth element-doped bismuth oxides with the fluorite structure (δ-Bi2O3) exhibit high oxygen ion conductivity at low temperature, which is promising electrolyte materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). However, traditional co-sintering process is not applicable to the manufacturing of IT-SOFCs using low melting point Bi2O3-based electrolyte, while further high-temperature processing is not required for deposition Bi2O3-based electrolytes. In this study, plasma spraying was used to examine the possibility to deposit high-performance Bi2O3-based electrolytes without the following high-temperature process. (Bi2O3)0.75 (Y2O3)0.25 (YSB) spray powders were prepared by the sinter-crushing method. The YSB electrolytes were fabricated by plasma spraying at different deposition temperatures. The effects of deposition temperature on the coating microstructure, crystalline stability, and ion conductivity were investigated. Results showed that the as-sprayed YSB electrolytes present a dense microstructure with well-bonded lamellar interfaces. The pure δ-phase YSB electrolyte was deposited with 37.5-75 μm powders at a deposition temperature of 350 °C. The deposited YSB electrolyte presented the excellent ionic conductivity of 0.19 S cm−1 at 700 °C in comparison with 0.21 S cm−1 for sintered bulk.

Enhancement of interface transportation for quantum dot solar cells using ultrathin InN by atomic layer deposition

Quantum dot-sensitized solar cells have gained rapid development which could produce potential applications. Although they have a theoretical photoelectric conversion efficiency of 44%, there is still a considerable gap in comparison with corresponding practical solar cells, which is mainly due to the fact that the interface transfer, stability and efficiency improvement are still facing some problems. In particular, the carrier recombination loss at the cell interface seriously hinders the quantum dot-sensitized solar cells from developing. In this work, an ultra-thin layer of InN prepared by plasma-enhanced atomic layer deposition is inserted into the FTO/TiO<sub>2</sub> interface of the photoanode of CdSeTe based quantum dot-sensitized solar cells to improve the performance of the photoanode structure, and physical mechanism behind the device is discussed. We first investigate the effects of different deposition temperatures (170, 200 and 230 ℃) on the cell performance of InN films. While the InN ultra-thin layer is deposited at 200 ℃, an enhancement of 16.9% in conversion efficiency is achieved as compared with the reference group. Then, the effects of different thickness (5, 10, and 15 cycles) on the cell are investigated at a fixed deposition temperature of 200 ℃. Additionally, an improvement of fill factor for the device after an introduction of InN layer is observed. This enhancement is further convinced by an apparent reduction of series resistance extracted by the Nyquist curve. The significant increase in fill factor indicates that the introduction of InN accelerates the extraction, transfer and separation of electrons, and reduces the possibility of photon-generated carriers recombination. However, the insertion of InN deposition temperature and thickness have a certain range of enhancement in the cell performance, and further investigation of the mechanism will be carried out.

Effects of Deposition and Annealing Temperature on the Structure and Optical Band Gap of MoS2 Films.

In this study, molybdenum disulfide (MoS2) film samples were prepared at different temperatures and annealed through magnetron sputtering technology. The surface morphology, crystal structure, bonding structure, and optical properties of the samples were characterized and analyzed. The surface of the MoS2 films prepared by radio frequency magnetron sputtering is tightly coupled and well crystallized, the density of the films decreases, and their voids and grain size increase with the increase in deposition temperature. The higher the deposition temperature is, the more stable the MoS2 films deposited will be, and the 200 °C deposition temperature is an inflection point of the film stability. Annealing temperature affects the structure of the films, which is mainly related to sulfur and the growth mechanism of the films. Further research shows that the optical band gaps of the films deposited at different temperatures range from 0.92 eV to 1.15 eV, showing semiconductor bandgap characteristics. The optical band gap of the films deposited at 200 °C is slightly reduced after annealing in the range of 0.71–0.91 eV. After annealing, the optical band gap of the films decreases because of the two exciton peaks generated by the K point in the Brillouin zone of MoS2. The blue shift of the K point in the Brillouin zone causes a certain change in the optical band gap of the films.

Effects of deposition temperatures on the supercapacitor cathode performances of GO:SnSbS/Si thin films

The performances of the new generation energy storage devices are strongly dependent on the physical and chemical properties of the electrode materials; therefore, the development of high-activity electrode materials is of great importance. For this purpose, Graphene oxide: Antimony sulfide (on Si substrate) thin films were produced at different deposition temperatures via chemical bath deposition (CBD) and their supercapacitor performances were investigated. Specific capacitance values were calculated through time-dependent current-voltage (I-V) measurements in the range of -0.2 V - 0.8 V, at 5 mV/s, 10 mV/s and 20 mV/s scanning rates. The maximum specific capacitance for each deposition temperature at scanning rate of 5 mV/s was found to be 562 F/g, 549 F/g, 401 F/g and 254 F/g, respectively.

Dendrite-free Al recycling via electrodeposition using ionic liquid electrolytes: The effects of deposition temperature and cathode surface roughness

In this paper, the electrodeposition of Al from aluminum scrap alloys (A2020) on copper cathode substrates with varied surface roughness under different deposition temperatures was studied using low-temperature AlCl3-1-butyl-3-methyl-imidazolium chloride (BMIC) ionic liquid electrolytes. The bulk electrodeposition of Al was carried out under a voltage of 1.5 V at a stirring rate of 120 rpm using a fixed ionic liquid electrolyte concentration (molar ratio AlCl3: BMIC = 2:1). The effects of deposition temperature (range from 80 °C to 140 °C) and surface roughness of Cu cathode substrates (polished by 320, 600, 800, 1200 grits SiC sandpapers and mirror polishing process) on the morphology of deposited Al, current density, current efficiency and energy consumption, were investigated. The Al deposits were characterized using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), profilometer, and electrochemical measurements for current density, current efficiency, and energy consumption. It is demonstrated that the deposition temperature and surface roughness of Cu electrodes play a critical role in the nucleation and growth of Al deposits. Higher deposition temperature promotes the diffusion and/or migration of Al2Cl7− ions and then enhances the current density and efficiency during the electrodeposition of Al. Smoother surface of Cu electrodes is preferred for the formation of dendrite-free Al deposits. Typically, on the mirror polished Cu electrode, no Al dendrite structure was observed, and only plate-like Al deposits were formed at the deposition temperature of 100 °C. Pure metallic Al was successfully deposited on Cu electrodes in AlCl3+BMIC ionic liquid electrolytes for all experiments with a current efficiency range from 72% to 99% and energy consumption of 4.6–6.3 kW h/kg Al.

Titanium Oxide Films Prepared by Cathodic Electrodeposition Method

In this paper, titanium oxide (TiO2) films were prepared by cathodic electrodeposition using titanium oxysulfate (TiOSO4), potassium nitrate (KNO3), citric acid, and hydrogen peroxide (H2O2) as reactants. The article investigated the effect of citric acid and deposition temperature on the structure and electrochemical properties of TiO2 films. The results indicated that hydrous TiO2 thin films were prepared at 60°C when no citric acid was added, while thin films containing hydrous TiO2 and anatase phase were fabricated at 60–75°C when citric acid was added. It was found that adding citric acid and raising the reaction temperature (60–75°C) were beneficial to reduce crack width until cracks disappeared. Adding citric acid facilitated phase transition from hydrous TiO2 to anatase. Continuous and uniform TiO2 thin film was prepared at 75°C, which was found to have ideal capacitive behavior with a rectangular cyclic voltammogram and high photocurrent performance with photocurrent 2.89 μA, which is several times higher than that of cracked samples.

Effects of substrate temperature on structural and optoelectronic properties of SnSe thin films by nebulized spray deposition for solar cell applications

SnSe thin films were prepared by nebulized spray deposition method at different substrate temperature of 250–325 °C. The effects of deposition temperature on the structural, morphological, electrical and optical properties of the films were evaluated using XRD, SEM, Hall Effect, UV and PL. The X-ray diffraction study reveals that the all films present an orthorhombic structure of preferred orientation along the (111) direction. From the recorded optical data indicates the existence of direct allowed band gap in the range of 1.14–1.24 eV was obtained. The electrical resistivity shows that the prepared films are semiconducting nature and resistivity is found to be low at the temperature of 300 °C.

Deposition-temperature dependence of structure, ferroelectric property and conduction mechanism of BCZT epitaxial films

Ba0·85Ca0·15Zr0·1Ti0·9O3 (BCZT) epitaxial films were successfully deposited on (001) Nb-doped SrTiO3 substrate, and the effects of deposition temperatures on the structure, ferroelectric property, and conduction mechanism were studied. The results of XRD and AFM verified the well epitaxial structure with smooth surfaces of the deposited BCZT epitaxial films. BCZT epitaxial films deposited at 650 °C exhibited the best ferroelectric property (2Pr = 22.91 μC/cm2, 2EC = 1702.11 kV/cm) and relatively low leakage current density (7.91 × 103 A/cm2). The conduction mechanism of BCZT films corresponds to the space-charge-limited current (SCLC) mechanism and the Fowler-Nordheim (F–N) tunneling mechanism in the low and high electric field range, respectively.

Compact Titania Films by Spray Pyrolysis for Application as ETL in Perovskite Solar Cells

Hybrid perovskite-based solar cells are projected as a potentially viable photovoltaic (PV) technology for large-scale implementation. The electron transport layer (ETL) should be dense and pinhole-free to facilitate efficient electron collection and transport from the perovskite layer to the anode, which is very important for achieving high-performance solar cells. In this study, a compact TiO2 layer was synthesized by a scalable spray pyrolysis technique. The effect of deposition temperature on the transparency, microstructure, and bandgap of c-TiO2 film was studied. Pinhole-free nanocrystalline films having > 85% transparency with uniform coverage was obtained on spray pyrolysis at 400°C and annealing at 450°C. Usability of the deposited films as ETL in perovskite solar cells was tested by fabricating solar cells (FTO/c-TiO2/FA0.85MA0.15Pb(I0.85Br0.15)3/CuSCN/Au) using the deposited films and comparing their performance. Cell efficiency close to 11.75% with a fill factor of 69% was obtained in the cell fabricated using the films deposited at 400°C.

The effect of molecular weight and deposition temperature on the formation of poly(ethylene oxide) films using the femtosecond pulsed laser deposition

Poly(ethylene oxide) (PEO) is a water-soluble, linear polymer with a high quantity of available molecular weights and is in many ways used in daily life. Coatings and films are an important issue for these applications. In this study, PEO films with average molecular weights of 1500, 2000, 4000, 20,000, and 200,000 g/mol were deposited by femtosecond pulsed laser deposition (PLD) on substrates held at 25 and −190°C. At room temperature, crystalline PEO films are formed with properties that coincide well with the precursor materials including the films of PEO-200,000, which contains chain lengths of around 1 μm. The deposition of PEO polymers at −190°C hinders the ordering in the films up to X-ray amorphous films for both PEO-20,000 and PEO-200,000. Upon warming to room temperature, the films crystallizes in the expected configuration. Furthermore, the analysis of the ejected molecules during the ablation process demonstrates the favorable light matter interaction of the ultrashort laser pulses. The results reveal the high potential of the femtosecond PLD as an easy and clean pathway for the preparation of intact polymer films.

Effect of Temperature on the Properties of Nickel Sulfide Films Performed by Spray Pyrolysis Technique

Abstract In this work, we have prepared new materials of the nickel sulfide thin films by using the spray pyrolysis technique for promising co-catalyst to improve the photocatalytic performance or superconductivity. The effect of deposition temperature (523, 573 and 623 K) on structural, optical and electrical properties was investigated. The XRD diffraction shows that the prepared nickel sulfide at 523, 573 and 623 K having an orthorhombic, hexagonal and hexagonal structure, which were Ni3S2, Ni17S18 and NiS2, respectively. The minimum value of crystallite size (45,9 nm) was measured of deposited film at 573K. The thin films prepared at 523 and 573 K have an average transmittance is about 20 %. The prepared Ni1S2 thin film at T=623 K has the lowest calculated optical band gap and Urbach energy. The Ni1S2 thin film also has the best calculated of the refractive index and the extinction coefficient. The FTIR spectrums of the nickel sulfide have various bands such as Ni-S, C-H, O-H, N–H and C-S. The maximum electrical conductivity is 4,29x105 (Ω.cm)−1 was obtained at 573K of the Ni17S18. The nickel sulfide thin films sprayed at 573K have good structural, optical and electrical properties.

Structure and Properties of AlCrN Coatings Deposited Using Cathodic Arc Evaporation

Al–Cr–N coatings were formed at various nitrogen pressures, substrate bias voltages and substrate temperatures using cathodic arc evaporation. The relationship between technological parameters and properties of the coatings was investigated. The phase and chemical composition of the coatings, roughness, hardness, adhesion and thermal stability were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), micro-indenter, Rockwell, scratch tester and thermomechanical methods. The corrosion resistance of selected coatings was also investigated. XRD analysis indicates that the coatings crystallize in a cubic structure and show preferential orientation (200) CrN. With the increase of nitrogen pressure, the preferential orientation changes to (111). EDX analysis shows that as nitrogen pressure increases, the Al/(Al + Cr) rate decreases. Microscopic observations indicate that the number of macroparticles reduces as nitrogen pressure increases. As a result, the surface roughness parameter Ra of the coatings decreases. The effects of deposition temperature, nitrogen pressure and substrate bias voltage on the mechanical and tribological properties of the coatings were investigated. It was found that the above parameters influence the mechanical properties in different ways. The hardness and adhesion of coatings formed at higher temperatures was lower. Coatings formed under a higher nitrogen pressure or substrate bias voltage were characterized by higher hardness and better wear resistance.

STUDYING THE MICROSTRUCTURE OF Pt LAYERS PREPARED BY CHEMICAL VAPOR DEPOSITION IN THE PRESENCE OF HYDROGEN

Platinum layers with developed surface areas are prepared for the first time on the contacts of diagnostic electrodes by chemical vapor deposition using the adduct between hexafluoroacetylacetonate-trimethylplatinum(IV) and pyridine used as the precursor in an atmosphere of hydrogen. The effect of the reagent gas concentration, deposition temperature, and gas phase activation temperature on the composition and microstructure of the films is studied by EDS, powder XRD, SEM, and Raman spectroscopy methods. The conditions of depositing films with minimal impurity contents are determined, the possibility of preparing layers with a fractal-like surface structure is demonstrated. The growth rate of the sample in the presence of hydrogen is shown to reach 3.2 nm/min. The regimes for the precipitation of functional layers on electrode contacts (capacitance values of 2.2-9.2 µF/cm2) and on Ti discs are determined.

Effect of Deposition Rate and Deposition Temperature on Residual Stress of HVOF-Sprayed Coatings

In this paper, we examine the correlation between thermal spray process parameters that affect the deposition rate and the residual stress buildup in HVOF metallic and cermet coatings. Parameters of interest including feed-rate, raster speed, and substrate temperature (controlled via external cooling means) were evaluated in the context of their effect on the stress evolution in gas fuel HVOF-sprayed coatings. The process variables investigated are intended to change the deposition rate and subsequently the local deposition temperature (TLD) at the location of impact. The residual stress during the deposition tends to be more tensile with increased TLD, and this tendency is more significant when the change in TLD is produced by the feed rate. Compressive stresses result for lower TLD due to dominance of the peening effect. A systematic study of these effects was conducted for gas fuel HVOF-sprayed Ni- and WC-12%wt.Co-coatings. The Ni-coatings represent the family of ductile metallic materials, whereas the WC-12%wt.Co-coatings represent the behavior of hard cermets. Both materials develop compressive stress at low TLD and change into tensile stress at high TLD by manipulation of deposition rate parameters. Extensions to other materials and HVOF processes are also presented to support the analysis.

Effect of deposition temperature on electrical properties of one-transistor-one-capacitor (1T1C) FeRAM devices

This work investigates the effect of process temperature on one-transistor-one-capacitor ferroelectric random access memory (1T1C FeRAM) cells fabricated with a HfZrOx ultrathin film applied as the 1T1C capacitor. Traditionally, the capacitor in 1T1C devices is grown on the drain, and such a structure is a type of dynamic memory. Such a structure, however, is prone to the leakage current phenomenon, which causes the amount of charge stored in the capacitor to be insufficient, leading to inaccurate data reading. To solve this problem, an alternative 1T1C structure placing the capacitor on the gate terminal has been proposed. For these alternative 1T1C FeRAM devices, our experimental results indicate that the deposition temperature of the ferroelectric layer has a significant effect on the basic electrical properties. To clarify this phenomenon, we propose a physical model which is based on the effect of the deposition temperature on the HfZrOx grain size.