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In this paper, Cu thin films were successfully deposited on glass substrates using DC magnetron sputtering at varying deposition times. The deposition time was varied as 5, 9, 11 and 17 min. The obtained Cu thin films were analyzed for morphology and topography using atomic force microscopy (AFM). The size of the surface structures/grains was seen to evolve with deposition time. The conventional/statistical, fractal and multifractal analyses were carried out on AFM images using existing imaging algorithms. The arithmetic roughness and interface width parameters were seen to evolve with the sputtering time. The autocorrelation and height–height correlation functions revealed that the surfaces of all the Cu thin films exhibited self-affine character, but were not mounded properties. The fractal dimensions computed using box counting and power spectral density functions revealed that larger dimensions were associated with larger surface features. The lacunarity coefficients were too small indicating that the surfaces were generally deficient in porosity and other defects. The multifractal analyses revealed that spatial roughness does not exhibit linear relationship with the deposition time. The study reveals that surface evolution and nanoscale behavior is significantly influenced by the deposition time although a linear relationship is not established. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO2) and many binary compounds of vanadium can transform from a semiconducting state to a metallic state under the influence of temperature or light. The transformation is triggered by modifications in the oxide's crystalline structure, often initiated by changes in its light-sensing and electrical attributes. This ability makes them suitable for smart coatings, electronic switches, self-cleaning surfaces, window glass, and many more. These potential applications have prompted tremendous interest in VO2thin films, focusing on their fabrication and application. This article reviews current fabrication methods for VO2thin films, the potential application of their thermochromic and photochromic properties in self-cleaning coatings, the challenges facing their application, and some remedies devised to address the challenges. The various challenges facing its different synthesis and fabrication methods are also highlighted. First, the different transitional phases of VO2and routes to transform from one stage to the other are presented. [ABSTRACT FROM AUTHOR]

This paper reviewed the deposition of thin films of TiO2 for self-cleaning applications deposited using the spin coater. The overwhelming global demand for electricity pushes power producers to develop substitute energy sources. Renewable energy sources such as solar, wind, tidal, geothermal, and hydroelectric are now considered to create alternative power sources. The most abundant form on earth is solar energy, converted to electrical energy using a solar panel. Regrettably, solar panels attract contaminants once exposed to the atmosphere, causing their efficiency to drop. Self-cleaning is one of the researched technologies to help maintain clean photovoltaic surfaces. Titanium dioxide (TiO2) is among the materials studied for self-cleaning, and the spin-coating method offers great promise. This paper presented the background and working principle of the spin coater, precautions to be taken with the spin-coating process, and the merits and demerits of the process. The paper highlighted the self-cleaning mechanism and the spin-coating method to create self-cleaning TiO2 thin films for application on several surfaces, including the solar panel. Commonly used self-cleaning materials were also reviewed, including materials used to dope or create TiO2 composite for better self-cleaning capability. Effects of process parameters, available substrates, surfactants, solvents, and stabilizing agents on the final TiO2 thin film performance and recent innovative efforts to improve the spin-coating process and the self-cleaning abilities of TiO2 are reviewed. This will contribute to the body of knowledge on spin-coating techniques, self-cleaning thin films, and TiO2. [ABSTRACT FROM AUTHOR]

A bibliometric analysis of publications on fractal theory and thin films is presented in this article. Bibliographic information is extracted from the Web of Science digital database and the bibliographic mapping undertaken using VOSviewer software. Based on the analysis, there is a growing trend in research on the applications of fractal theory in thin film technology. The factors driving this trend are discussed in the article. The co-citation, co-authorship and bibliographic coupling among authors, institutions and regions are presented. The applications of fractal theory in thin film technology are clarified based on the bibliometric study and the directions for future research provided. [ABSTRACT FROM AUTHOR]

Thin superconducting films have been a significant part of superconductivity research for more than six decades. They have had a significant impact on the existing consensus on the microscopic and macroscopic nature of the superconducting state. Thin-film superconductors have properties that are very different and superior to bulk material. Amongst the various classification criteria, thin-film superconductors can be classified into Fe based thin-film superconductors, layered titanium compound thin-film superconductors, intercalation compounds of layered and cage-like structures, and other thin-film superconductors that do not fall into these groups. There are various techniques of manufacturing thin films, which include atomic layer deposition (ALD), chemical vapour deposition (CVD), physical vapour deposition (PVD), molecular beam epitaxy (MBE), sputtering, electron beam evaporation, laser ablation, cathodic arc, and pulsed laser deposition (PLD). Thin film technology offers a lucrative scheme of creating engineered surfaces and opens a wide exploration of prospects to modify material properties for specific applications, such as those that depend on surfaces. This review paper reports on the different types and groups of superconductors, fabrication of thin-film superconductors by MBE, PLD, and ALD, their applications, and various challenges faced by superconductor technologies. Amongst all the thin film manufacturing techniques, more focus is put on the fabrication of thin film superconductors by atomic layer deposition because of the growing popularity the process has gained in the past decade. [ABSTRACT FROM AUTHOR]

The variation of the purge flow rate is investigated in a reactor scale simulation of a typical atomic layer deposition (ALD) process. The investigation in its context addresses the possible issues of inadequate deposition rates with regard to the purge flow rate. A three-dimensional reactor is numerically implemented to simulate the physical and chemical processes to fabricate aluminum oxide (Al2O3) thin films. The purge flow rate disparity is focused to examine the effects within the fluid flow, mass transport, along with the chemical kinetics of the ALD process. The fabrication process employs trimethyl-aluminum and ozone (O3) as the metal and oxidant precursors, respectively, and inert argon as the purge gas. The reactor operation is set up to operate at a pressure of 10 torrs, with a substrate temperature of 200 °C. Three purge flow rates of 20, 10, and 5 sccm, respectively, have been examined. It was discovered that the slower flow rate showed, superior mass fraction distribution, reached unity surface coverage, and a time extensive surface deposition rate. A prolonged ozone exposure was crucial in providing an adequately oxidized substrate. The 20, 10, and 5 sccm purge flow rate growth obtained a 0.58, 0.85, and 1.6 Å/cycle, respectively. These findings revealing close similarities to experimental behaviors and recorded growths. [ABSTRACT FROM AUTHOR]

Inconel thin coatings exhibit outstanding oxidation and corrosion-resistant appropriate for application in severe environments that are prone to heat and pressure. They can form a stable and passivating oxide layer, which protects metal surfaces from been attacked. Inconel also retains their strength over a wide range of temperatures, and this makes them a material of choice for high-temperature applications ahead of steel and aluminum, which yield to creep more easily because creation of vacancies in their crystals are easily thermally provoked. Inconel thin coatings are majorly accomplished on substrates through chemical or physical processes at different deposition parameters and conditions. This study is centered more on Inconel thin coatings prepared by physical deposition techniques since published literature has already established that they have more exceptional characteristics compared to those of the chemical deposition techniques. The review, therefore, examines the characteristics of Inconel thin coatings and their intricate relations with process conditions and parameters such as rate of deposition, deposition time, the temperature of substrates, power, the temperature of deposition, the surface finish of substrates, and deposition pressure. The characteristics of the coatings are also affected by the properties of subtracts and subsequent treatment employed on them. Hence, the importance of optimizing the coating techniques was highlighted in this review, and research gaps in published works were further uncovered. The work can be an essential basis for selecting vital processing parameters in the physical deposition of Inconel thin coatings. [ABSTRACT FROM AUTHOR]

The substrate temperature of Ge2Sb2Te5 (GST) optoelectronic devices can influence various physical parameters, which could be helpful for tuning optoelectronic device structure and working performance as per desired use. Therefore, it is customary to demonstrate the GST/indium tin oxide (ITO)/substrate device structural, optical, and electrical properties with various substrate temperatures, such as room temperature, 150°C, and 200°C. It has been observed that a distinct phase formation in Ge2Sb2Te5 thin films occurs with increasing substrate temperature. An increase in the thickness of the thin films with increasing substrate temperature is verified by field emission scanning electron microscopy (FESEM) cross-sectional view, while the presence of the alloying elements and their particle distributions throughout the configuration are confirmed from energy-dispersive spectroscopy (EDS) and EDS mapping. The developed distinct morphological grains and corresponding roughness parameters of the thin film are interpreted with the help of atomic force microscopy (AFM) results. Moreover, the Raman spectroscopic broad peak of GeSbTe along with a distinguishable difference in GeTe phase peak height is also noticed. The correlation of Raman peak phase formation is described with the help of mapping analysis. Additionally, the Fourier transform infrared (FT-IR) (UV/visible range) transparency property and electrical parameters like I–V and R–V characteristics under the applied distinct voltages are also interpreted for these systems. [ABSTRACT FROM AUTHOR]

The objective of this study was to synthesize and characterize a novel green synthesis of copper niobate (CuNb2O6) thin film using copper (II) sulfate pentahydrate (CuSO4 · 5H2O), an organometallic precursor of bis(cyclopentadienyl) niobium (IV) dichloride (C10H10Cl2Nb), using Allium cepa as a catalyst. The synthesized thin film was characterized using the XRD, EDX, SEM FTIR, UVvis, and 4-point probe measurement. The XRD patterns of the thin film affirmed the formation of a pure monoclinic CuNb2O6 phase. Similarly, the SEM images illustrated the formation of the film and the different film microstructures. The EDX revealed that the thin film consisted of copper (Cu), niobium (Nb), and oxygen (O) elements. The thin film, however, possessed broad absorption in the Ultraviolet-Visible (UV–Vis) region with an absorption edge at 340 nm and an optical bandgap evaluated to be 3.18 eV. Also, the fabricated film's transmittance ranged between 40% and 55%. A Raman shift of 690 cm−1 was identified at the CuNb2O6 film. The results obtained from the FTIR analysis demonstrated characteristic IR bands at 608 cm−1 and 940 cm−1 which indicated the formation of the Cu-O and Nb-O-Nb bonds. With the rising temperature, an increase in conductivity and a decrease in resistivity were noticed from the plots. This indicated that the synthesized CuNb2O6 thin film exhibited good semiconducting qualities. The prepared CuNb2O6 thin film thus possesses improved electrical properties and can therefore be effectively utilized in photovoltaic solar cells. [ABSTRACT FROM AUTHOR]

This report demonstrates nontoxic colloidal nitrate route CZTS (Cu2ZnSnS4) synthesis at room temperature, along with their band grading due to incorporation of Ge as cost of Sn (3%). The parent CZTS, CZGTS (Cu2ZnGeSnS4), and their polyvinyl alcohol (PVA), dimethyl sulfoxide (DMSO) solvent containing solutions doctor blade-coated thin film structural and optical properties are discussed. Their sulfurized thin films thickness have been achieved ±2 μ. It has noticed that addition of Ge in CZTS alloy affects the grain sizes, crystallographic structure, Raman spectral peak shift toward the higher wave number side. The addition of PVA and DMSO is also substantially contributed in their physical property modification by demonstrating the gradual improvement in grain sizes and compactness. Moreover, the gradual changes have also appeared in their X-ray diffractometer (XRD) and Raman spectroscopic results. The optical energy band gaps of the CZTS, CZGTS, and their PVA, DMSO mixed alloyed thin films are obtained in between 1.27 eV to 1.57 eV and 1.58 eV to 1.83 eV. [ABSTRACT FROM AUTHOR]

Due to its exceptional electrical, optical, chemical and magnetic properties, tin oxide (SnO and SnO2), which is a functional material, has gained enormous attention for use in a variety of applications. Films of SnOX have a direct band gap between the ranges of 2.2 and 3.6 eV, with these films finding usefulness in various functions such as solar cells, transparent conducting oxides for gas sensors, lithium-ion batteries and microelectronics, and use in the optoelectronics industries. In order to satisfy the needs of a broad range of these applications, thin films with an extensive properties span defined by film composition, thickness, structural properties and morphology are required. This article explains the theory and research status of the various manufacturing processes of tin oxide. The purpose is to analyze the effects of the thin films through distinct forms of deposition. The general finding summarized in this research on SnOX showed that various researchers studied specific characteristics of tin oxide properties restricted by experimental conditions. [ABSTRACT FROM AUTHOR]

The attractive key-enabling nanotechnology manufacturing technique of atomic layer deposition (ALD) is well-known to deposit ultra-thin, uniform, conformal and pinhole-free nano-films on complex topography. Over the years it has been used to deposit ultra-thin films in a multitude of industry applications such as microelectronics, solar cells, superconductors, fuel cells, and water purification membranes, among other applications. This study investigates the ALD process effects in the fabrication of Al2O3 thin film over the substrate. The mass fraction coverage over the substrate and deposition rate contours in a Gemstar 6 ALD reactor are examined. The analysis technique illustrates the parameter behavior over a Cartesian coordinate sector in a three-dimensional illustration. The governing laws of the conservation of mass, momentum, energy, species, and kinetic chemical reactions are analyzed numerically by ANSYS Fluent and ChemkinPro. The deposition rate profiles correlated with previous experimental findings in the literature, producing an average growth rate of 1.3 Å/cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] Tetrakis (dimethylamino) tin(IV) (TDMASn) is a metal organic precursor used for fabricating transparent conducting tin oxide (SnO 2) thin films via atomic layer deposition process (ALD). This study reported for the first time, a spin coating fabrication process of transparent conducting SnO 2 thin films using TDMASn as the precursor for electrode materials of solar cells substrate. The samples were prepared using sol–gel spin-coating process and annealed at different temperatures to form metastable crystal structured SnO 2 thin films. The manufactured thin films consequently underwent X-ray diffraction (XRD), scanning electron microscope (SEM), UV–vis spectroscopy, and resistivity analysis. The XRD analysis certified the films to be of polycrystalline structure, with the SEM results revealing variations in film thicknesses. The UV–vis analysis demonstrated a peak absorption band at 250 nm, while the highest transmittance of 83.2% in the visible range was noticed at the 550 °C sample. [ABSTRACT FROM AUTHOR]

10 Consolidation mechanism of Inconel coatings as related to their corrosion behavior [[1]] The original article has been corrected. Reference 1 Olakanmi EO, Malikongwa K, Nyadongo ST, Hoosain S, Pityana SL (2020) Consolidation mechanism, microstructural evolution and corrosion resistance of Inconel 625 coatings. [Extracted from the article]

This study aimed to synthesize copper oxide (CuO) thin films using an eco-friendly green synthetic approach. A sol-gel spin coating technique was employed for the synthesis of the CuO thin film using Allium cepa as a reducing agent. The fabricated CuO thin film was investigated using the Fourier Transform-Infrared (FTIR) spectroscopy, Ultraviolet-visible spectra studies (UV-Vis), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and the Four-Point Probe measurement. The SEM micrographs revealed that the particles were spherically shaped, while the EDX analysis revealed that the CuO thin film was composed of copper and oxygen elements. Furthermore, the XRD analysis confirmed the monoclinic crystalline structure of the CuO thin film, while the FTIR spectroscopy investigated the chemical bonds formed during the production process. Contrarily, the UV-Vis spectroscopy reported a strong absorption of the film at the visible spectra with an estimated optical energy band gap of 1.48 eV. The electrical analysis, however, disclosed that the synthesized thin film portrayed good semiconducting behaviors. [ABSTRACT FROM AUTHOR]

Niobium oxides (NbO, NbO2, Nb2O5), being a versatile material has achieved tremendous popularity to be used in a number of applications because of its outstanding electrical, mechanical, chemical, and magnetic properties. NbxOy films possess a direct band gap within the ranges of 3.2–4.0 eV, with these films having utility in different applications which include; optical systems, stainless steel, ceramics, solar cells, electrochromic devices, capacitor dielectrics, catalysts, sensors, and architectural requirements. With the purpose of fulfilling the requirements of a vast variety of the named applications, thin films having comprehensive properties span described by film composition, morphology, structural properties, and thickness are needed. The theory, alongside the research status of the different fabrication techniques of NbxOy thin films are reported in this work. The impact of fabrication procedures on the thin film characteristics which include; film thickness, surface quality, optical properties, interface properties, film growth, and crystal phase is explored with emphases on the distinct deposition process applied, are also described and discussed. [ABSTRACT FROM AUTHOR]

In this study, we performed nanoindentation test using the molecular dynamic (MD) approach on a selected thin film of palladium, vanadium, copper and niobium coated on the vanadium substrate at a loading rate of 0.5 Å/ps. The thermosetting control is applied with temperature variance from 300 to 700 K to study the mechanical characteristics of the selected thin films. The effects of temperature on the structure of the material, piling-up phenomena and sinking-in occurrence were considered. The simulation results of the analysis and the experimental results published in this literature were well correlated. The analysis of temperature demonstrated an understanding of the impact of the behaviour. As the temperature decreases, the indentation load increases for loading and unloading processes. Hence, this increases the strength of the material. In addition, the results demonstrate that the modulus of elasticity and thin-film hardness decreases in the order of niobium, vanadium, copper and palladium as the temperature increases. [ABSTRACT FROM AUTHOR]

This study communicates a novel route for the synthesis (and characterization) of semiconducting Nb 2 O 5 thin films at different annealing temperatures for solar cell applications, performed with the use of an organometallic niobium precursor in the form of bis(cyclopentadienyl)niobium(iv)dichloride (C 10 H 10 Cl 2 Nb) via a sol-gel spin coating deposition process. [Display omitted] In this research study, the optical, electrical and structural properties of synthesized niobium pentoxide (Nb 2 O 5) thin films using bis(cyclopentadienyl)niobium(IV)dichloride(C 10 H 10 Cl 2 Nb) as the organometallic niobium precursor have been reported. The samples were formed via the sol-gel spin coating deposition process and calcined at varying temperatures to produce Nb 2 O 5 thin films. The fabricated thin films were then subjected to Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Ultraviolet-visible spectroscopy and electrical tests. The XRD showed the films to have an orthorhombic structure, while the EDX indicated the presence of niobium oxide in the thin films. The SEM analysis revealed that the films consisted of nanometric spheres, with the FTIR spectroscopy illustrating the formation of an Nb-O-Nb bond. Also, the thin films showed a high absorbance coefficient in the UV region, with 3.61 eV as the lowest optical energy bandgap at 700 °C. The conductivity and resistivity tests confirmed that the synthesized thin films were good semiconductors. The correlation between the different analyses with respect to the annealing temperatures of the Nb 2 O 5 thin films was also discussed. [ABSTRACT FROM AUTHOR]

• In cases where deposition is required on surfaces of complex structures such as trenches and holes, the precursors must be transported to the targeted surface despite the interference the complexity it possesses. • O3 pulse shows that more coverage is achieved in the presence of exposure time at higher pressure. • The trenches appear to be evenly covered, as a 0.58% surface coverage difference is observed in the compared tests. • The trenches appear to be evenly covered, as a 0.58% surface coverage difference is observed in the compared tests. • A higher deposition rate may however be achieved with a higher operating pressure, while the conformal growth will be converted inferior to that of a lower operating pressure. Tremendous interest has been placed on the atomic layer deposition (ALD) process as a thin film deposition technique capacity to deposit quality thin films. However, further comprehension of the ALD process is mandatory to increase the probability of achieving the necessary improvement, which can have a substantial impact on devices' requiring properties that involve size, performance, and durability. It has been reported that pressure tends to impact growth per cycle. However, little has been done to investigate the specific effects of the – operating pressure on the mechanistic, species transport and reaction rates. Moreover, the effect of these prior properties due to complex topology elements, such as micro-trenches, has rarely been investigated. Hence, this study focuses on numerically investigating the effect between 1 and 10 Torr operating pressure along the ALD process using the computational fluid dynamic approach. A two-dimensional numerical simulation producing Al 2 O 3 ALD thin film over a surface with micro-trenches is studied. Trimethyl-Aluminium and Ozone were utilized as the metal and oxidation source reactants. To assist in the precursor reaction process, a 2.5 s exposure time is added within the ALD sequence. The findings illustrated the fluid flow velocity, surface coverage, mass fraction, deposition rate and growth of the thin-film process. The mechanistic fluid flow along with the ALD Nano-manufacturing process over a trenched substrate Image, graphical abstract [ABSTRACT FROM AUTHOR]