Effect Of Substrate Temperature Research Articles

Surface Nanostructures Promote Droplet Splash on Hot Substrates.

Splash, one of the most visually apparent droplet dynamics, can manifest on any surface above a certain impact velocity, regardless of surface wettability. Previous studies demonstrate that elevating the substrate temperature can suppress droplet splash, which is unfavorable for many practical applications, such as spray cooling and combustion. Here, we report that the suppression effect of substrate temperature on splash is nullified by utilizing surfaces with nanostructures. By manipulating air evacuation time through surface nanostructures, we have identified a pathway for precise control over the splash threshold and the ability to tailor the dependence of the splash onset on surface temperature. We further propose a theoretical criterion to determine different splash regimes by considering the competition between air evacuation and the development of flow instabilities. Our findings underscore the crucial role of nanostructures in splash dynamics, offering valuable insights for the control of splash in various industrial scenarios.

Effect of Si concentration and substrate temperature on the microstructure and magnetic properties of FeCoNiCu0.5Six high entropy alloy films

It has been known that Si has the effect to increase the resistivity, permeability, and to decrease the magnetostriction coefficient in Si-containing steel as soft magnetic material. On the other hand, high-entropy alloys are intensively studied as soft magnetic materials in recent years, especially as thin films. In the present work, Si-containing (FeCoNiCu0.5Six) high entropy alloy films (HEAFs) have been prepared by magnetron co-sputtering under different deposition conditions. The microstructure and magnetic properties of FeCoNiCu0.5Six HEAFs have been investigated to clarify the effects of Si concentration on microstructure formation and magnetic properties. It has been found that Si addition strongly affects the magnetic properties of FeCoNiCu0.5Six HEAFs of FCC phase by decreasing the coercivity of the films, but hardly affects the phase formation in the films. On the other hand, it has been found that deposition of the films at moderate high substrate temperatures greatly improve the magnetic properties by increasing the saturation magnetization while keeping low coercivity.

The effects of substrate temperature on the reproductive success of Caretta caretta on a volcanic beach in the Mediterranean Sea

A five-year of monitoring (2018–2022) of the loggerhead sea turtle Caretta caretta nests in “Pozzolana di Ponente” beach on Linosa Island (Pelagie Archipelago, Italy) is here reported. To explore how temperatures affect the hatching success and the possible occurrence of any malformation in hatchlings, incubation temperature values were recorded using data loggers positioned at depths of 5 and 35 cm (for each nest) from the surface, approximately 0.5 m from the nest chamber. The obtained results highlighted important issues related to the success of hatching and the incidence of body anomalies. The temperatures recorded at different depths near the nests (5 and 35 cm) in some periods of incubation of the eggs were above optimal development temperature (i.e., ~33°C), causing high mortality rates, especially during the first two years of the survey (2018–2019). In the next three years (2020–2022), the implementation of shading cover cloths of the nests increased the survival rate and decreased the incidence of malformed individuals. Furthermore, atmospheric temperature data were extrapolated from the “Copernicus Climate Change” web service and included in our analyses to assess any changes over the timeframe analysed. Over five years (2018–2022), the average atmospheric temperature increased slightly by 1.7°C. In light of global warming, the implementation of effective and low-cost mitigation activities, such as the use of shade cloth covers to protect the nests from overheating, should be considered a suitable conservation action.

Effect of substrate temperature on growth mechanism and properties of PEALD-MgO dielectric films for amorphous-IGZO TFTs

Magnesium oxide (MgO) films have been prepared by plasma enhanced atomic layer deposition with bis(cyclopentadienyl)magnesium precursor and oxygen plasma reactant at substrate temperature between 150 °C and 450 °C. The structural, morphological, optical, and chemical properties of the prepared MgO films were studied by spectroscopic ellipsometer, grazing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS). The electrical property of MgO film was obtained by performing capacitance-voltage measurement on the Al/MgO/Si structures. The experiment result shows that growth rate of MgO film decreases with the deposition temperature increased. GIXRD analysis presented that MgO films are cubic with predominantly (220) crystal orientation. XPS analysis shows that ratio of Mg/O is highest in MgO film prepared at 350 °C. To illustrate the possible applications of MgO film as a gate dielectric in thin film transistor (TFT), indium‑gallium‑zinc oxide (IGZO) was used as channel layer. The optimized IGZO/MgO TFT showed an electron mobility of 1.63 cm2/Vs, an on/off current ratio of 106, and a subthreshold swing of 0.50 V/decade at a low operation voltage of −0.11 V.

Effects of As8 structure formation on the surface morphology and internal microstructure of GaAs thin films.

Gallium arsenide (GaAs) materials have the advantages of high electron mobility, electron saturation drift rate, and other irreplaceable semiconducting properties. They play an important role in the electronics, solar and other fields. However, during GaAs film sedimentary growth, As atoms can undergo segregation to form As8 clusters because of the influence of external factors, which affect the surface morphology and internal structure of these films. In this study, a series of investigations on the deposition and growth of GaAs crystal films were performed. Additionally, the deposition and growth of GaAs thin films were simulated using molecular dynamics. The influence of As8 clusters on the surface morphology and internal structure of GaAs films at different incidence angles, velocities and substrate temperatures was studied by using "defect analysis technology" and "diamond structure identification" in open source software, along with surface roughness and radial distribution function. Results show that with increasing incident angle, the number of As8 clusters decreases and film density increases. Increasing incident velocity increases the irregular movement of As8 clusters in air, and their deposition on the film surface affects the morphology of the film, the surface roughness increases first and then decreases. Additionally, we investigated the effect of different substrate temperatures on the film surface. Results show that at a substrate temperature of 1173 K, the number of As8 clusters in the film decreases or the As8 clusters disappear, heterogeneous nucleation occurs in the film, and the crystallization rate increases. Although the dislocation line associated with nucleation may affect the mechanical and optical properties of the film, it considerably reduces the annealing effort after the deposition and growth.

Influence of substrate temperature on the structural, morphological, and photoelectric properties of Bi2WO6 thin films deposited by magnetron sputtering

The effect of substrate temperature (Ts) increasing from RT (room temperature) to 600 °C on the structural, morphological, optical and photoelectrochemical properties of BixWO6 (1.98≤x ≤ 2.84) thin films deposited by RF magnetron sputtering has been investigated by various techniques including XRD, EDS, SEM, AFM, XPS, UV–vis DRS, PL and EIS. AFM and EDS show that as Ts increases, the Bi/W atomic ratio gradually decreases; the amorphous BixWO6 thin films grown under 300 °C had a very smooth surface with an RRMS value in the range of 0.5–0.8 nm. However, as the substrate temperature increases from 400 to 600 °C, for the crystalline BiWO6 thin films the RRMS value increases to a range of 18.3–30.5 nm and there is a transition of the crystalline orientation from {131} to {200} as confirmed by XRD. The films grown at Ts = 600 °C exhibit some favorable properties such as a Bi/W ratio close to 2:1, lattice expansion relaxation, low Eg and excellent photoelectric reproducibility which is about 3–29 times higher than that of other films grown at low Ts (300–500 °C). PL and EIS analysis as well as photoelectrochemical test results demonstrated the enhanced separation efficiency of photogenerated electron-hole pairs and charge transfer for the stoichiometric and well-crystallized BixWO6 thin films, showing their good potential for practical applications such as visible light responsive photocatalyst or photoelectrode.

Improved photoelectrochemical performance of tungsten-catalyzed graphene nanoplatelet electrodes prepared by hot-wire chemical vapor deposition at low substrate temperatures

The current increase in demand for graphene in various energy applications such as electrode materials for supercapacitors, batteries, thermoelectric, and hydrogen production via water-splitting, the production of high-quality graphene, considering its fascinating physical and electrical properties, high-yield, and large-area has becoming more challenging at the research and development level. Therefore, in this work, graphene nanoplatelets (GNPs) were directly grown on tungsten nanoparticle (W NP)-coated p-type crystalline silicon and quartz substrates using hot-wire chemical vapor deposition at low substrate temperatures (<500 °C). Prior to the GNP deposition, a plasma process was employed to induce the formation of W NPs, which act as a metal catalyst for facilitating the growth of large-area and multi-layer GNPs. The W NPs were formed at substrate temperatures ranging from 250 to 550 °C, with the largest graphene sheet was grown at 450 °C. Higher substrate temperatures promote the growth of high-quality graphene layers with high intensities of G (IG) and 2D bands (I2D), and high I2D/IG ratio values. The GNP photoelectrode prepared at 450 °C demonstrated better photoelectrochemical responses with the highest photocurrent density of 1.65 mA/cm2 at 1.5 VAg/AgCl, the lowest charge transfer resistance (14.0 kΩ), and the highest donor density (2.57 × 10 28 cm−3) compared to the tungsten carbide thin film and W NP electrodes prepared at the same temperature. The effects of substrate temperature on the optical, structural, and photoelectrochemical properties of the as-grown GNPs are discussed.

Substrate temperature dependent crystal structure and deep-ultraviolet photodetection of ZnGa2O4 thin films * *Project supported by This work was supported by the National Natural Science Foundation of China (No. 12074044), the Fund of State Key Laboratory of Information Photonics and Optical Communications (IPOC2021ZT05), and the Fundamental Research Funds for the Central Universities (BUPT, 2023ZCJH1).

Zinc gallate (ZnGa2O4) is a promising material for deep-ultraviolet (DUV) photodetectors, owing to its wide bandgap and high transparency. However, the effect of substrate temperature on the structural and optical properties of ZnGa2O4 thin films prepared by magnetron sputtering is not well understood. Here, we report a systematic study of the influence of substrate temperature on the crystal quality, stoichiometry, bandgap, and photodetection performance of ZnGa2O4 thin films deposited on sapphire substrates. We find that the films undergo a phase transition from amorphous to polycrystalline at 300 °C, and then to single crystalline at 500 °C, accompanied by an increase in the bandgap from 4.6 to 4.9 eV. We also fabricate metal-semiconductor–metal photodetectors based on the ZnGa2O4 thin films with Ti/Au electrodes, which exhibit excellent Ohmic contact and high light-to-dark current ratio. The photodetectors show remarkable and stable DUV response, with the highest performance achieved at a substrate temperature of 650 °C. Our results demonstrate the crucial role of substrate temperature in tailoring the crystal structure and DUV photodetection of ZnGa2O4 thin films, and provide a facile route for optimizing their performance.

Effect of Substrate Temperature on Cu₂-xO Growth for Enhanced Photodetector Performance in Visible Region

Effect of Substrate Temperature on Cu₂-<i>x</i>O Growth for Enhanced Photodetector Performance in Visible Region

Effect of substrate temperature on properties of deposited Nb2O5 thin films prepared by RF sputtering for gas sensing applications

Effect of substrate temperature on properties of deposited Nb2O5 thin films prepared by RF sputtering for gas sensing applications

Effect of substrate temperature on ultrasonic spray deposited film morphology and coffee stain effect

Effect of substrate temperature on ultrasonic spray deposited film morphology and coffee stain effect

Simulating multi-particle deposition based on CEL method: studing the effects of particle and substrate temperature on deposition

The subject matter of this study is to use numerical simulation methods to study the influence of the temperature of particles and substrates on the post-deposition coating during the multi-particle deposition process of cold spray. The goal is to study the temperature of Al6061 particles and the temperature of the substrate, which are factors that have a greater impact on the deposited coating, and to observe the shape of the coating and the temperature distribution of the cross-section of the substrate after deposition. The tasks to be solved are as follows: use Python scripts to model multi-particles, generate and randomly assign positions according to particle size distribution in the Euler domain, and establish a cold spray multi-particle collision model to simulate the process of cold spray deposition. The following methods were used: The influence of temperature and substrate temperature on the deposited coating was studied through a single variable method; the Coupled Eulerian Lagrangian (CEL) method was used to simulate the collision process of cold-sprayed Al6061 multi-particles. The following results were obtained: changing the temperature of Al6061 particles has a more obvious control effect on the porosity of the deposited coating; after particles of different temperatures impact the constant-temperature substrate, the high-temperature area on the surface of the substrate is mainly located at the junction of pits; after the particle temperature reaches 650K, the coating changes after deposition are no longer significant, indicating an optimal temperature range for Al6061 particle deposition; increasing the temperature of the substrate can increase the depth of particle deposition on the substrate; at the same time, it serves as a reference basis for further using the CEL method to predict the porosity of the Al6061 coating. Conclusions. The scientific novelty of the results obtained is as follows: 1) powder preheating can effectively reduce the porosity of Al6061 coating; 2) the CEL method has good robustness and is used to simulate cold spray multi-particle deposition to monitor the porosity of the coating, which cannot be achieved by the SPH and ALE methods.

Thermodynamic control the self-assembled formation of vertically aligned nanocomposite thin film

ABSTRACT Emergent exotic phenomena in the self-assembled process of vertically aligned nanocomposite (VAN) thin film remain under intensive studies. Insight exploration on the self-assembled formation from the combination of two different phases of materials is not only important to optimize the physical properties yields from those combined materials, but also open up a new avenue to discover new materials with the VAN system. In this work, the thermodynamic control of the self-assembled formation of BiFeO3-CoFe2O4 (BFO-CFO) VAN thin film has been confirmed by studying the effects of substrate temperature during the growth process by pulsed laser deposition (PLD) technique. The structural examination results on the samples, which were growing with various substrate temperatures highlight the importance of the thermodynamic factor to control the crystalline structure of BFO phase and CFO pillar size, which then affect the physical properties and further its practical applications. For instance, we can control the size of the CFO pillar using a temperature substrate to find appropriate spin magnetic switching in the CFO pillar for memory device applications. This study also sheds light on the relationship between thermodynamics and elastic strain energy on the formation of self-assembled matrix-pillars of the BFO-CFO VAN which is important for device fabrication.

Effect of Substrate Temperature and Deposition Power on the Surface Morphology and Optical Properties of ZnO:Mg Thin Films Deposited by DC Magnetron Sputtering

Magnesium doped zinc oxide (ZnO:Mg) thin films were deposited on soda lime glass slides by DC magnetron sputtering method. Atomic force microscope (AFM), and UV/VIS spectrophotometer were used to investigate the effect of sputtering power and substrate temperature on the surface morphology and optical properties of ZnO:Mg thin films. AFM images revealed that sputtering power and deposition temperature have significant influence on surface morphology of the ZnO:Mg thin films. For all sputtering powers and substrate temperatures investigated, ZnO:Mg films had peak transmittance above 85%. Samples deposited at 110 W sputtering power and 450 °C substrate temperature showed the best peak transmittance of &gt; 90% at 560 nm (visible range). Optical band gap of ZnO:Mg films was in the range of 3.44– 3.69 eV depending on the substrate temperature. The results indicated the potential of the films for transparent conductor applications.

Tailoring the nanotwin spacing of Ni-Mo-W alloys via composition and substrate temperature control

Alloy chemistry and deposition conditions can strongly influence the structure and properties of nanostructured materials. However, in Ni-Mo-W alloys, the limited influence of deposition rate on the twin spacing compels the exploration of other routes to tailor the structure and properties. This study was undertaken to investigate the effect of composition and substrate temperature on the nanotwin spacing of sputter-deposited Ni-Mo-W alloys. Increasing the Ni content from 84 at.% to 93 at.% doubled the average twin spacing from 1.8 nm to 3.8 nm, while raising the substrate temperature from room temperature to 200°C for a fixed Ni content of 91 at.% resulted in an increase from 2.9 nm to 5.0 nm. Concurrent weakening of the {111} texture occurred with both increased Ni and temperature. The combined effectiveness of composition and temperature demonstrated here provides a potential process window for tuning the twin spacing while maintaining the strongly textured columnar structure.

Effect of substrate temperature on structure, morphology and optical properties of Sb2Se3 thin films fabricated by chemical-molecular beam deposition method from Sb and Se precursors for solar cells

Sb2Se3 thin films were obtained by chemical-molecular beam deposition on soda-lime glass from high purity Sb and Se precursors at 400 °C, 450 °C and 500 °C substrate temperature. Due to the precise control of the Sb/Se ratio, Sb2Se3 thin films with stoichiometric composition were obtained, which was confirmed by energy-dispersive X-ray microanalysis. The effect of substrate temperature on morphology, structure and optical properties of Sb2Se3 thin-films were studied by scanning electron microscopy, atomic force microscopy, X-ray diffraction, Raman spectroscopy and from the analysis of absorption and transmission spectra of the films. Average diameters and lengths of Sb2Se3 rods deposited at different substrate temperature were the range of 0.5–2 µm and 1–4 µm respectively which was grown at different slope and compactness to the substrate. The optical bandgap of the films was determined from the transmission and reflection spectra and 1.16, 1.21 and 1.26 eV band gap energies were observed for 500, 450 and 400 ℃ substrate temperature Sb2Se3 thin films respectively.

Substrate temperature dependence of vapor phase deposition of all-inorganic lead-free CsSnBr3 perovskite thin films

We report the effect of substrate temperature on the vapor phase deposition of all-inorganic lead-free tin halide perovskite CsSnBr3 thin films by co-evaporation of CsBr and SnBr2. The amount of SnBr2 supplied had little effect on the thin film when the substrate temperature exceeded the SnBr2 effusion cell temperature (∼180 °C) indicating that the three-temperature growth was realized. The polycrystalline CsSnBr3 thin films obtained by three-temperature growth showed micrometer-scale grains and no by-products. The average grain size increased for higher substrate temperatures following the Arrhenius law with an activation energy of 6.6 kJ mol−1.

The effect of substrate temperature on the preparation of molybdenum oxide thin films by spray pyrolysis method used in diode

The effect of substrate temperature on the preparation of molybdenum oxide thin films by spray pyrolysis method used in diode

ANALYSIS OF THE DYNAMICS AND FREEZING OF WATER DROPLETS ON METAL SURFACES

This article investigates the effects of substrate temperature, tilt angle, and droplet size on droplet impact dynamics and freezing using a Motionpro high-speed camera and a DSA-30 droplet surface analyzer. The temperature of the substrate was changed from the ambient temperature of 21&amp;deg;C to -13&amp;deg;C, and three droplet sizes (&lt;i&gt;D&lt;/i&gt;&lt;sub&gt;0&lt;/sub&gt; &amp;#61; 2.57, 3.02, and 3.54 mm) were studied. The results show that some air gets trapped under the liquid film during the impact process due to insufficient escape time, resulting in the interior of the droplet being in an unstable state. Simultaneously, due to the low surface energy of the substrate, liquid droplets exhibit a rebound effect upon impact with the ambient temperature substrate, reaching their maximum height and forming a dumbbell-like shape. Furthermore, the rebound height decreases rapidly with the decrease in substrate temperature. A change in substrate temperature had no significant effect on the droplet spreading process, but decreasing substrate temperature increased the viscous forces, thereby suppressing the droplet retraction and oscillation processes, ultimately leading to longer droplet freezing times. Additionally, at low Weber numbers (&lt;i&gt;We &lt;/i&gt;&amp;#60; 250), the droplet dimensionless parameters exhibited a similar trend with respect to dimensionless time or temperature.

Growth and Structural Characterization of h-LuMnO3 Thin Films Deposited by Direct MOCVD.

In this work, we investigated the MOCVD conditions to synthesize thin films with the hexagonal P63cm h-LuMnO3 phase as a potential low-band gap ferroelectric material. The main parameters investigated were the ratio of organometallic starting materials, substrate temperature, and annealing effect. Two different substrates were used in the study: fused silica (SiO2) glass and platinized silicon (Pt\Ti\SiO2\Si(100)). In order to investigate the thermodynamic stability and quality of the developed phases, a detailed analysis of the crystal structure, microstructure, morphology, and roughness of the films was performed by X-ray diffractometer, scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), Raman spectroscopy, and piezoelectric force microscopy (PFM). Molar compositions in the film within 0.93 < |Lu|/|Mn| < 1.33 were found to be suitable for obtaining a single-phase h-LuMnO3. The best films were obtained by depositions at 700 °C, followed by thermal treatments at 800 °C for long periods of up to 12 h. These films exhibited a highly crystalline hexagonal single phase with a relatively narrow direct band gap, around 1.5 eV, which is within the expected values for the h-LuMnO3 system.