Influence Of Substrate Temperature Research Articles

Epitaxial growth of nano-texturized NiO films on MgO (001) substrates by a reactive magnetron sputtering method

Epitaxial films with nanostructures are of great significance for some special applications. In this work, nano-texturized NiO films are epitaxially grown on MgO (001) substrates by a reactive magnetron sputtering method. The evolution in morphology is studied as a function of deposition time, and the influences of substrate temperature, oxygen partial pressure, and the substrate treatment before deposition of NiO on the formation of nano-texturized NiO films are explored. It is found that the non-symmetrically epitaxial growth of nano-texturized NiO films can be linked with the surface damages of MgO (001) substrate, which leads to the coalescence of adjacent NiO grains preferentially occurs along the direction of 〈100〉 and 〈010〉, but they do not coalesce simultaneously following the other directions. In addition, the optical property of nano-texturized NiO films is studied using the Cauchy model.

Low temperature growth of MgGa2O4 films for deep ultraviolet photodetectors

MgGa2O4 films were grown on the (0001) sapphire substrates by using pulsed laser deposition at substrate temperatures ranging from 100 to 500 °C. The influences of substrate temperature on the structural and optical properties of the films have been systematically investigated. Deep ultraviolet (DUV) photodetectors were demonstrated by using the MgGa2O4 films as wavelength-selective absorber layers. The photodetectors based on the MgGa2O4 films grown at 500 °C exhibited excellent peak responsivity (0.18 A/W) around 220 nm, high rejection ratio (R220 nm/R350 nm = 104), and reproducibility. Our results obtained in this work indicate the pulsed laser deposition is a promising technique for obtaining high quality MgGa2O4 film at low growth temperature, paving the way to realize high performance DUV photodetectors based on MgGa2O4 film for novel optoelectronic applications.

Influence of Substrate Temperature on the Morphology and Phase Composition of Thin Films Prepared From Y-123 Targets by the IJD Method

The Ionized Jet Deposition method (IJD) is a relatively new and rapidly evolving physical vapour deposition technique. IJD has significant potential for cost-effective scale-up fabrication of thin films. Furthermore, IJD's flexibility allows the preparation of thin films from a wide range of materials, due to the possibility of adjusting many depositions parameters. The substrate temperature is crucial as it fundamentally affects the deposition of Y <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> Ba <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7-x</sub> (YBCO or Y-123). Desired Y-123 phase formation depends primarily on the substrate temperature and target stoichiometry. This work was focused on substrate temperature optimization during the deposition in the range from 700 to 830 °C. Thin films were prepared using Y-123 targets and a constant accelerating voltage of 14 kV. The phase composition of the samples was analysed by the XRD using the grazing incident geometry. The homogeneity and surface morphology were studied by SEM method confirming a surface morphology with “droplets” typical for the HTS thin films prepared by IJD.

Stages of self-arrangement in growth of nanostructured graphene films related to the flow of ionized species during plasma-enhanced chemical vapor deposition

The ability to directly deposit graphene layers on diverse substrates (including the ones with existing functioning electronic devices) is a very attractive method for integrating two-dimensional materials into electronic systems based on typical semiconductors. However, the task is highly challenging due to the high temperatures required for synthesis of the graphene structures. Plasma-enhanced chemical vapor deposition is an option that can be used to produce large-area graphene layers at sufficiently low temperatures. A lack of deep understanding of the plasma-associated processes limits the ability to directly control graphene growth. In this study, we experimentally investigated how the density of the ionized species flow influences the growth of the nanostructured graphene layers using a custom process chamber layout. The relationship between the growth of the nanostructured carbon-based films and the flow of the ionized species of the working gas mixture was quantitatively characterized for a set of specific parameters. We also analyzed the influence of deposition time and substrate temperature on the growth of the films and discuss the driving mechanisms. Three unique stages were identified in the self-arrangement of the layer. The activation energy of the process was ∼0.31 eV.

Optimization of Esterase Production in Solid-State Fermentation of Agricultural Digestate

The continuous increase in biogas production poses the need for innovative applications for its by-products. Solid-state fermentation (SSF) has regained attention in the development of several products because of the possibility to use low-cost and easily available substrates, such as organic wastes. SSF represents a valuable process for agricultural digestate valorization in terms of enzyme production. In the present study, cellulase and esterase were produced by Trichoderma asperellum R on a digestate-based substrate in SSF, with esterase as the highest obtained activity. After assessing the effect of light on it, the esterase production in SSF was optimized using response surface methodology. The influence of substrate composition, temperature and humidity on the enzyme production was evaluated on two sets of data generated based on digestate concentration (50% and 70% w/w). The statistical analyses revealed that these parameters affected esterase production only when Trichoderma asperellum grew on substrate containing 50% w/w of digestate. The best esterase activity (264.6 mU/mg total protein) was achieved with the following optimized SSF parameters: 50% digestate, 50% fruits, 10% sawdust, 30 °C. The current finding of esterase production on digestate-based substrates makes the SSF method presented here a sustainable and completely circular technology.

Impact of spray angle and particle velocity in cold sprayed IN718 coatings

Cold spray (CS) deposition has potential applications in repair technology or additive manufacturing due to its ability to operate at low temperatures, achieve high deposition rates, and produce thick, dense coatings. For adoption of CS in repair applications, it is crucial to evaluate the influence of spray angles since geometry of repair zones are typically complex and non-flat. In this work, we investigated the influence of spray angles and particle velocities on the cold spray deposition of Inconel 718 (IN718) powder particles using N2 as propellant gas. Three oblique spray angles including 50, 60 and 70° were compared with the 90° normal spray angle for cold spray deposition of IN718 powders on Al6061 substrate. Three sets of cold spray parameters at each spray angle, giving particle velocities from 820 to 920 m/s were employed to study their effect on the coating properties. Particle velocity was found to have greater impact on coating porosity compared to spray angle. Coating with lowest porosity and lowest surface roughness but highest compressive surface residual stress was achieved with deposition at lowest spray angle (50°) and highest particle velocity (920 m/s). Changing the spray angle has greater influence on the deposition efficiency, with thickest coating observed at normal spray angle of 90° across all three cold spray conditions. Finite element method (FEM) simulations were also performed to understand the influence of powder and substrate temperatures on critical angles for bonding. The simulation results suggest that elevating the powder temperature is likely to cause a slight increase in the critical bonding angle.

Formation of the Structured Indium Tin Oxide Films by Magnetron Sputtering

The influence of substrate temperature on the morphology of indium tin oxide films deposited by magnetron sputtering and electron beam evaporation is demonstrated. It is found that during magnetron sputtering, the degree of film structuring increases with a rise in the substrate temperature. Based on the X-ray phase analysis of the samples, the structured films are described in terms of two phases: the first of which is an untextured sublayer with the properties corresponding to the material obtained at room temperature; the second one is textured elongated crystals with a large cell parameter, a large crystallite size, and without microstrains. The structural features and optical characteristics of studied films are compared with the structured film obtained by electron beam evaporation. The study of transmission and reflection spectra of the obtained films show that the film deposited at a temperature of 400°C are characterized by the antireflection effect over a wide range of wavelengths.

Opto-electronic properties of Zr[formula omitted]Hf[formula omitted]O[formula omitted]/Al/Zr[formula omitted]Hf[formula omitted]O[formula omitted] thin-films: The influence of substrate temperature

The influence of substrate temperature on ZrxHf1−xO2/Al/ZrxHf1−xO2 trilayer thin-films deposited on n-type Si(100) and commercial glass substrates using magnetron sputtering technique is systematically investigated with the substrate temperature ranging from 25 to 300°C. The deposited films are characterized by x-ray reflectivity (XRR), grazing incidence x-ray diffraction (GI-XRD), x-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FE-SEM), atomic force microscopy (AFM), cross-sectional transmission electron microscope (TEM), energy-dispersive x-ray spectroscopy (EDX) and UV–VIS spectroscopy to study the microstructural, morphological and optical properties. Capacitance–voltage (C–V) and current–voltage (I–V) measurements are performed to investigate the electrical properties of the trilayer thin-films. Physical characterization reveals that as the substrate temperature rises, the crystalline quality of the trilayer thin-films improves. Further, a rise in substrate temperature causes an increase in surface roughness and grain size. The trilayer thin-film deposited at 300°C shows improved optical transmittance over wavelengths 400–1100 nm. In addition this trilayer thin-film demonstrates highest figure of merit, lower leakage current as well as improved breakdown performance. Hence, ZrxHf1−xO2/Al/ZrxHf1−xO2 thin-film prepared at 300°C could be used in opto-electronic devices.

The optical properties of In2S3 films in the far-infrared spectral range

Optical reflection spectra of In2S3 thin films (180 – 730 nm) deposited on glass substrates are measured by infrared spectroscopy using the synchrotron radiation of BESSY II storage ring in the spectral range of 30 – 8000 cm−1. The aim of the study is to find the influence of different substrate and post-annealing temperatures on the electron and phonon systems of In2S3 films deposited on glass. Clear features in the reflectance spectra for the studied films have been found mainly in the phonon excitation range 100 – 400 cm−1. The experimental dielectric functions ε(ω) of In2S3 films are found to be in good agreement with the calculated ones obtained for In2S3 crystals within the density functional theory. The dielectric functions ε(ω) of the films in the range of 100 – 400 cm−1 depend substantially on the post-annealing temperature. This indicates a transition of the film from the amorphous to the crystalline state. The thorough analysis of the frequency dependence of the reflection coefficient R(ω) and optical conductivity σ(ω) in the wavenumber range of 30 – 130 cm−1 allowed us to reveal the distributed electron states in In2S3 films.

High-Entropy Alloy Films

High-entropy alloy films have the same excellent properties as high-entropy alloys and can better realize the practical applications of high-entropy alloys. This paper takes the high-entropy alloy films as the object of discussion. The preparation process, microstructure, hardness, wear resistance and corrosion resistance of high-entropy alloy films are mainly discussed and the influence of nitridation, sputtering power, substrate temperature, substrate bias and other factors on the phase structure of alloy films is analyzed. High-entropy alloy films can be prepared using magnetron sputtering, laser cladding, pulsed laser deposition, detonation spraying, electrochemical deposition and other processes. High-entropy alloy films tend to form a solid solution and amorphous state, and their hardness is far higher than that of traditional films. Among them, the hardness of high-entropy alloy nitride films can reach the standard of superhard films. Wear resistance is usually proportional to hardness. Due to the corrosion-resistant elements and amorphous structure, some high-entropy alloy films have better corrosion resistance than stainless steel. High-entropy alloy films have shown profound development prospects in the fields of wear-resistant coatings for tools, corrosion protection, diffusion barrier and photothermal conversion coatings.

Influence of Substrate Temperature on Microstructure of Zirconium Silicon Nitride Thin Films Deposited by Reactive Magnetron Sputtering

Influence of Substrate Temperature on Microstructure of Zirconium Silicon Nitride Thin Films Deposited by Reactive Magnetron Sputtering

FTO Thin Films: Outcome of Substrate Temperature on the Structural and Optical Properties

In this work, Fluorine doped Tin Oxide (FTO) thin films are effectively deposited by JNSP technique using ammonium fluoride and tin chloride as solution composition. The influence of Substrate Temperature (ST) on the structural and optical properties of FTO thin films is investigated. XRD pattern authenticates the presence of single phase polycrystalline orthorhombic structure with favored orientation along (230) and (200) directions. The sharp band obtained between 475 and 700 cm-1 originated from asymmetric stretching vibrations of metal oxide (SnO2:F). The highest band gap energy was obtained as 3.57 eV at 425°C and lowest band gap energy was obtained as 3.49 eV at 450°C obtained from UV-Vis spectra.

Influence of Substrate Temperature on Structural Properties of CdS Thin Films Prepared by Chemical Spray pyrolysis

الملخص:في هذا البحث تم تحضير أغشية CdS الرقيقة بطريقة شلل الرذاذ الكيميائي على طبقة زجاجية بدرجات حرارة مختلفة عن نترات الكادميوم بسمك ثابت (440 ± 10 نانومتر) ، لدراسة تأثير درجة حرارة الركيزة على خواص بنية الأغشية المحضرة.أظهرت نتائج القياسات الهيكلية من خلال مجهر المسح الإلكتروني (SEM) تجانس الأفلام المعدة ، ومن نتائج مجهر القوة الذرية (AFM) ، فإن الجسيمات النانوية هي التركيب وقيمة الجذر التربيعي لمتوسط ​​الخشونة (RMS) ) من الأغشية الرقيقة متساوية (0.699 نانومتر). ومن نمط حيود الأشعة السينية ، أظهرت النتائج أن جميع الأفلام متعددة البلورات ، وهيكل سداسي ، وحجم الحبيبات في نطاق مقياس النانو ، ودرجة حرارة الركيزة لا تؤثر على التركيب البلوري للأغشية ، وأن الفيلم المحضر له اتجاه مفضل على طول (002) (أي المحور C عمودي على الركيزة).الكلمات الرئيسية: CdS ، CSP ، الخواص التركيبية.

Quantitatively characterizing the evolution of hole defects between overlapped aluminum droplets by a two-dimensional solidification model

Quantitatively characterizing the effect of process parameters on the evolution of holes in metal droplet 3D printing enables effective prediction and elimination of hole defects in printed parts. In this work, a two-dimensional solidification model is proposed to quantitatively characterize the influence of substrate temperature on hole morphologies between overlapped aluminum droplets. First, a phenomenon is observed in experiments that the surfaces of overlapped droplets show typical "L"-shaped solidification ripples, which indicates that the solidification of overlapped droplets involves two-dimensional solidification. Hole defects are formed in the transition area of two-dimensional solidification. In addition, the appearance of the first L-shaped ripple signifies that the hole is no longer changing. Based on this discovery, a two-dimensional solidification prediction model for the hole size is constructed by combining a hyperbola and the one-dimensional heat transfer model to trace the ripple, which can accurately demonstrate the relationship between the hole size and the parameters (i.e., the thickness of solidified layer X(t) , the two-dimensional solidification angle β , the solidification angle θ ). The hole formed between the two overlapped droplets can be divided into two parts: the hole Ⅰ caused by the two-dimensional solidification and the hole Ⅱ caused by the morphology of the previously deposited droplet. When X(t) ≤ 0 at the end of the spreading of the overlapping droplets on the substrate, the hole can be completely eliminated. This work provides effective theoretical guidance for the prediction and elimination of hole defects in metal droplets printed parts.

English

Recent interest in the cultivation and use of butterfly pea (Clitoria ternatea L.) has increased demand for its commercial production. Successful germination of seed is a critical first step to its production; however, few studies have documented factors influential to germination success. To help support commercial production efforts, the influence of substrate temperature and seed scarification technique on germination parameters were evaluated. Two scarification (nicked and soaked) and three substrate temperature treatments (21, 24 and 27&deg;C) were imposed on C. ternatea seed. Following treatments, six germination parameters were recorded. Data showed seeds maintained at a substrate temperature of 21&deg;C reached maximal germination (54.8%) at the longest mean germination time (2.61 d) and slowest mean germination rate (0.39 day-1). Mechanical scarification by nicking the seed coat with a razor blade prior to soaking the seed for 24 h reached maximal germination (80.95%) at the lowest mean germination time (2.06 days) and fastest mean germination rate (0.51 day-1). Optimal germination was attained when seed was scarified and soaked and then germinated in rockwool substrate maintained at a temperature (To) of 21&deg;C. Results provide commercial growers with production technique information helpful to fast and efficient germination of C. ternatea seed. Key words: Germinability, medicinal, edible, rockwool.

Influence of substrate temperature on structure, stoichiometry, and energy band gap of Zn1 − xMgxO thin films deposited by pulsed laser deposition

Influence of substrate temperature on structure, stoichiometry, and energy band gap of Zn1 − xMgxO thin films deposited by pulsed laser deposition

The Effect of Ag-Doping on the Cytotoxicity of ZnO Nanostructures Grown on Ag/Si Substrates by APMOCVD

The search and development of new nanostructures and nanomaterials are very important for the progress of nanotechnology and modern microbiology. Due to the unique properties of silver and zinc oxide, these nanoparticles are the optimal basis for creating nanostructures with potential antiviral activity. An important issue in these studies is the establishment of cytotoxicity of these nanoparticles and their composites. Aim. To define the influence of substrate temperature and Ag concentration in ZnO lattice on the microstructure and cytotoxicity of zinc oxide nanostructures. Methods. Pure and Ag-doped ZnO nanostructures were grown on Ag/Si substrates by atmospheric pressure metalorganic chemical vapor deposition method using a mixture of zinc acetylacetonate and silver acetylacetonate powders as a precursor. Argentum thin films were deposited on Si substrates by a thermal evaporation method. MTT-assay was used for the analysis of MDBK and MDCK cell viability in the definition of zinc oxide nanostructure cytotoxicity. Results. Ag-doped zinc oxide nanostructures were grown and characterized by X-ray diff raction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. It was found that Si substrate and pure zinc oxide do not inhibit the cell viability of both epithelial cultures whereas Ag-doped ZnO nanostructures inhibit the cell viability because of all-time exposure in a sample without dilution. The cytotoxic effect was not observed at higher dilutions for Ag-doped zinc oxide nanostructures. Conclusions. The investigation of the effect of Ag-doping on the morphology and cytotoxicity of zinc oxide nanostructures is very important for implementing zinc oxide nanostructures into the current optoelectronics and photocatalysis.

Heating influence on hierarchical structures fabricated by direct laser interference patterning

The combination of direct laser interference patterning (DLIP) with laser-induced periodic surface structures (LIPSS) enables the fabrication of functional surfaces reported for a wide spectrum of materials. The process throughput is usually increased by applying higher average laser powers. However, this causes heat accumulation impacting the roughness and shape of produced surface patterns. Consequently, the effect of substrate temperature on the topography of fabricated features requires detailed investigations. In this study, steel surfaces were structured with line-like patterns by ps-DLIP at 532 nm. To investigate the influence of substrate temperature on the resulting topography, a heating plate was used to adjust the temperature. Heating to 250 ^{circ }C led to a significant reduction of the produced structure depths, from 2.33 to 1.06 µm. The reduction is associated with the appearance of a different LIPSS type, depending on the grain orientation of the substrates and laser-induced superficial oxidation. This study revealed a strong effect of substrate temperature, which is also to be expected when heat accumulation effects arise from processing surfaces at high average laser power.

Influence of substrate temperature on the optical and vibrational properties of RF sputter coated NiO:WO3 thin films for optoelectronic applications

Mixed nickel –tungsten oxide thin films denoted as NiO:WO3 were prepared at 100 W rf power with varying substrate temperatures (Tsub = 100, 200, and 300 °C) using radio frequency (RF) magnetron sputtering technique. The influence of substrate temperature (Tsub) of NiO:WO3 thin films was studied in detail. All the prepared samples were found amorphous in nature with very fine smooth morphology. The average transmittance decreases from 88% to 83% with increasing substrate temperature. The energy band gap (Eg) decreases from 3.43 to 3.21 eV with increasing substrate temperature. AFM study revealed the roughness value of 0.875 nm. The detected binding energy values of Ni, O, and W observed from XPS study were, 853.7 and 871.8 eV with their respective satellite peaks at 859.88 and 878.2 eV corresponding to Ni 2p3/2 and Ni 2p1/2, O 1 s peaks at 529.51 eV due to Ni2+ ions and the higher binding energy peak at 531.13 eV due to the Ni3+ ions, peaks at 35.2 and 37.3 eV, corresponds to W 4f7/2 and W 4f5/2. The relationship between the refractive index and energy band gap proposed by different models was discussed. The refractive index (n) evaluated from these models shows an increase in n values with increasing Tsub owing to an increase in interaction among the molecules of NiO:WO3 and effect of these interactions on light. The derived optical constant k decreases from 0.024 to 0.022 indicating the decreased optical loss. The dielectric constants vary between 5.262 and 5.439 for ε1 and 0.113-0.106 for ε2 with variation in Tsub. The room temperature photoluminescence (RTPL) spectroscopy showed emission bands around 368 nm and 423 nm corresponding to the transition of 3 d8 Ni2+ ions. Micro-Raman analysis shows two broad peaks due to Ni–O bond vibrations at 570 cm−1 and 1100 cm−1, while the peak found at 870 cm−1 is due to a W–O bond vibration. We have aimed to discuss these results and correlate them with possible mechanisms behind the phenomena.

Impact of structural and optical properties tunability of SnSe2 thin films on its optoelectronic properties

As a result of the precise controllability of the properties of tin diselenide and the possibility of harmonious integration with silicon technology in many applications. Attention was focused on tin diselenide and the effect of many variables during or after growth on its properties, especially the optoelectronic and photovoltaic. Consequently, a systematic study is represented on the substrate temperature influence (27–200) °C on the crystal structure, morphology, optical and electrical properties of the deposited films. Depending on the results obtained from the XRD, FE-SEM, spectrophotometric, and DC conductivity measurements, the elevation of substrate temperature up to 100 °C achieved the highest crystallite and grain size which has been accompanied by the lowest energy gap and highest conductivity. Furthermore, the dispersion behavior is analyzed and interpreted with detailed calculations for the dielectric and electronic parameters. Next, under the same conditions of the substrate temperatures, isotype (Bi2Te3/SnSe2) and anisotype (Sb2Te3/SnSe2) heterojunctions are fabricated. Their microelectronic parameters are estimated, yielding an ideal Schottky behavior and lower barrier height (0.67 eV) for Sb2Te3/SnSe2 at the optimum temperature. The conduction mechanism is interpreted in detail using the proposed band diagram. Moreover, the effect of power density variation on the two categorized devices is investigated, giving rise to a bias-dependent photodetection behavior of the isotype heterojunction and a significant self-powered photodetection behavior for the anisotype heterojunction. The anisotype detector records R, D*, LDR, and SNR of about 299 mA/W, 1.71 × 1011 Jones, 69.89 dB, and 3121.4, respectively. Ultimately, the photovoltaic characteristics of the anisotype heterojunction have been evaluated in detail, yielding a promising performance of Voc, Jsc, FF, and PCE of about 0.547 volts, 29.9 mA/cm2, 38.09, and 6.23%, respectively.