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Transparent flexible display devices have attracted massive attention in recent years owing to their practical applications that can be compatibly adapted to human demand and technological development. Worldwide researchers have studied flexible transparent thin film transistors (TFTs) to qualify them for the backplane component of future transparent and flexible displays. Simplifying the fabrication process of a TFT can be considered a critical need for reducing consumed cost, time, toxic chemicals. In this study, sputtering was utilized as a major fabrication method for manufacturing a transparent oxide TFT device, which demonstrated good mechanical flexibility. A simple surface treatment process was applied to enhance the susceptibility of the sputtered Al 2 O 3 dielectric through multiple coatings of solution processed Al 2 O 3. It is noteworthy that the transparent oxide TFT device exhibits a high optical transparency of 81.12% and good electrical switchability at low operating voltage (3 V) with a decent mobility of 4.37 cm2 V−1 s−1 and proven mechanical durability. [ABSTRACT FROM AUTHOR]

Herein, the temperature‐dependent characteristics of AlN/Al0.5Ga0.5N high electron mobility transistors (HEMTs) with highly degenerate n‐type GaN (d‐GaN) ohmic contacts fabricated via pulsed sputtering deposition (PSD) are investigated. The ohmic contacts formed at the source and drain regions demonstrate low resistivity within the temperature range of 77–473 K. It is found that the temperature dependence of the contact resistance (RC) for the AlN/Al0.5Ga0.5N HEMTs with regrowth d‐GaN contacts is attributable to the energy barrier induced by the Fermi level difference between the d‐GaN contacts and Al0.5Ga0.5N channel layer. Notably, the RC between the d‐GaN contacts and the channel layer is 1.4 and 0.15 Ω mm at 77 and 473 K, respectively. Temperature‐dependent device on‐resistance coincides with the temperature variation of the two‐dimensional electron gas sheet resistance because the contact resistance is negligibly low in the studied temperature range. Moreover, AlN/Al0.5Ga0.5N HEMTs with d‐GaN contacts exhibit excellent switching characteristics, achieving an ION/IOFF ratio of ≈106, even at high temperatures up to 473 K. The results indicate that the PSD d‐GaN contact technique has potential to overcome the limitations of ohmic contacts for high Al‐composition AlGaN electronic devices, especially for next‐generation high‐power‐density radio frequency transistors operating at high temperatures. [ABSTRACT FROM AUTHOR]

Electrolytic capacitors are known to be fast devices with very low time constant and able to deliver high power. This class of capacitors is then an interesting technology to power miniaturized embedded electronics for Internet of Things applications. However, the current electrolytic capacitor suffers from its bulky size that does not fit with the miniaturization. To solve this issue, a proof‐of‐concept consisting of miniaturizing an electrolytic capacitor based on tantalum materials to give rise to a new class of electrolytic micro‐capacitors is proposed. To reach this ambitious objective, thin films (<100 nm) of tantalum metal (Ta), tantalum nitride (TaN), and tantalum oxide (Ta2O5) are deposited on a Si substrate by sputtering deposition method. After a careful optimization of the deposition parameters, Ta/Ta2O5 and TaN/Ta2O5 electrodes (Ta and TaN ≈45 nm and Ta2O5 ≈25 nm) and study their behaviors when biased at high voltage (>20 Volts) in aqueous electrolyte are produced. The Ta/Ta2O5 and TaN/Ta2O5 interfaces when the electrode is polarized near and beyond the breakdown voltage of the dielectric layer are carefully investigated. Polarizing the electrodes beyond the breakdown voltage are shown to result in anodization‐like mechanisms. In the case of the TaN/Ta2O5 electrode, an N‐rich porous layer grew within the Ta2O5 layer as polarization increased. A comparative study on the 2 stacked layers electrodes with different compositions (Ta/Ta2O5 and TaN/Ta2O5) but similar thicknesses (45/25 nm) is carried out: both electrodes show excellent capacitance retention of over 90% over 300 000 cycles. The frequency behavior of Ta/Ta2O5 and TaN/Ta2O5 electrodes shows that both are potential candidates in electrolytic micro‐capacitors for powering miniaturized electronics. [ABSTRACT FROM AUTHOR]

Here, we report room temperature deposition of nickel oxide (NiO) thin films on silicon and glass substrates by direct current (dc) magnetron sputtering using a metallic nickel target. The effect of sputtering power (20 W, 25 W, and 30 W) on the thin films, their surface scaling, fractal dimension, and optical properties are extensively investigated. Autocorrelation and height–height correlation functions were applied to AFM images to extract deep insights about the thin films' surfaces. Fractal dimension (D f) was extracted through the power spectral density (PSD) function. Various scaling exponents, including α, β, and 1/z, of the NiO film's surface were independently observed. The local roughness exponent, α, was approximately 0.81 for films deposited with 20 W sputtering power and decreased to 0.71 with higher sputtering power. The interface width (σ) scales with sputtering power (Sp) as ∼ Spβ, with a growth exponent (β) value of 1.17. The lateral correlation length (ξ) follows as ∼ Sp1/z with a 1/z value of 0.703. Additionally, optical parameters were recorded through UV–Vis. optical spectroscopy, and an attempt was made to correlate them with fractal parameters (D f & α). Optical absorption (reflection) increased (decreased) with increasing D f values. The minimum (maximum) reflection (absorption) was observed on the roughest surface (D f = 2.29). The calculated band gap decreased with increasing fractal dimension. This investigation suggests that sputtered surfaces with minimal reflectivity, band gap, and enhanced light-absorbing capacity could potentially be used as active solar layers for advanced optoelectronic devices. [ABSTRACT FROM AUTHOR]

In today's modern world, energy consumption continues to escalate. In such cases, smart windows play a crucial role in reducing energy consumption and enhancing the quality of life. Electrochromic devices (ECDs) -based smart windows rely profoundly on nickel oxide (NiO) thin films, which act as a counter electrode in ECDs. This work aims to fabricate NiO thin films, with the intention of achieving ultrafast ECD. Through the sputtering technique, energy-efficient ECD is obtained with the highest optical modulation of 60 % at a rapid switching speed of 0.55s for bleaching and 0.95s for coloration. We have also investigated the structural, morphological, vibrational, and optical properties of NiO thin films. XRD analysis revealed the less crystalline or near amorphous nature of NiO thin film. XPS, PL, and Raman studies confirm the existence of defects in the film. The favourable, less crystalline nature, along with the presence of defects, facilitates ultra-fast ion intercalation and de-intercalation process. We believe that prepared NiO film can be used as a promising anodic colourant in electrochromic smart windows with applications in energy-efficient buildings. [ABSTRACT FROM AUTHOR]

Optical losses of perovskite/silicon tandem solar cells can be effectively reduced by optimizing the thin‐film layer thicknesses. Herein, the thicknesses of DC sputtered indium tin oxide (ITO) films, which serve as the front electrode and the recombination layer connecting the subcells, are optimized to reach high transparency and good lateral charge transport simultaneously. Optical simulations of the full perovskite/silicon tandem solar cell stacks are performed to find the optimum recombination and front electrode ITO thicknesses for solar cells as well as modules. Implementation of the optimized 25 nm front electrode ITO thickness in semitransparent single‐junction perovskite solar cells increases the short‐circuit density by 1.5 mA cm−2 compared to the former reference thickness of 75 nm. Combined with an optimized 20 nm recombination ITO layer, high short‐circuit density of 20.3 mA cm−2 is reached in perovskite/silicon tandem solar cell devices, which is the highest reported value for planar front perovskite/silicon tandem solar cells to the best of knowledge. Further interface passivation enables 28.8% power conversion efficiency. [ABSTRACT FROM AUTHOR]

In this study, TiO2 coatings are deposited on Si(100) wafers by direct current pulsed magnetron sputtering technology. The crystal structure of TiO2 coatings gradually transforms from the anatase phase to the amorphous phase when the sputtering power is decreased from 900W to 150W. Besides, the growth surface temperature of TiO2 coatings decreases from 630∘C to 241∘C. The relationship between the growth behavior and growth surface temperature of TiO2 coatings is investigated using the dynamic scaling theory. The results show that in the first stage, the growth behavior of TiO2 coatings gradually transforms from the Frank–van der Merwe mode to the Volmer–Weber mode with decreasing sputtering power from 900W to 150W. In the second stage, the growth behavior of TiO2 coatings gradually transforms from the Stranski–Krastanov mode to the Volmer–Weber mode. Transformation of the growth behavior of TiO2 coatings in the second stage transforms the crystal structure of TiO2 coatings from the anatase phase to the amorphous phase. [ABSTRACT FROM AUTHOR]

The main goal of this work is to use a simplified idea to provide a scientifically accurate plasma device at a reasonable cost and benefit to society. It is an attempt to present designing and building one plasma system that can operate as three plasma experiments using the same instruments. These experiments are glow discharge, magnetron, and sputtering. This study focused on working the device as a DC glow discharge argon plasma device by a positive electrode made of a copper rod. The Paschen curve was measured at different distances between the cathode and the anode (4, 6, 8, 10, and 12 cm). From these results, the operating conditions of argon gas pressure and voltage that will produce plasma at each distance were determined. The investigated pressures were 1 × 10 - 1 and 2 × 10 - 1 mbar, while the operating voltage ranged from 110 to 160 V. The generated plasma was used to clean and polish the surface of two Egyptian fifty-piaster coins (still in circulation) at different exposure times as a practical application for the designed plasma device. After that, the results will be compared with cleaning and polishing a coin by a chemical method. The observed cleaning and polishing by the plasma is better and resists the environmental effect more than the chemical polishing method. This is related to the plasma treatment of the surface of the metal, while the chemical replaces the dirty layer as a result of reaction with it without treating the metal surface itself. The reversed effect of the sample (coins) on the plasma parameters (voltage and current) during its exposure time is considered one of the most novel included in this work. Besides, the temperature increases of the chamber surface during the working time were recorded. [ABSTRACT FROM AUTHOR]

Biospecimen imaging is essential across various fields. In particular, a considerable amount of research has focused on developing pretreatment techniques, ranging from freeze-drying to the use of highly conductive polymers, and on advancements in instrumentation, such as cryogenic electron microscopy. These specialized techniques and equipment have facilitated nanoscale and microscale bioimaging. However, user access to these environments remains limited. This study introduced a novel technique to achieve high conductivity in bioimaging by employing a magnetically controlled sputtering cathode to facilitate low-temperature deposition and low-electron bombardment. This approach allows for the convenient high-magnification observation of highly structured three-dimensional specimens, such as pill bugs and butterfly wings, and fragile specimens, such as single-cell protozoan parasites, using metal deposition only. Furthermore, it is easily accessible in the field of bioimaging because it does not require any pretreatment and enables surface analysis of biospecimens with an electron microscope using only a single pretreatment process. Protozoa, which are microorganisms, were successfully observed at high magnification without structural changes due to thermal denaturation. Furthermore, metallic film deposition and electrochemical signal measurements using these metallic films were achieved in pill bugs. [ABSTRACT FROM AUTHOR]

In current years, the growth of high-k dielectric thin films with reduced charge density and leakage current has drawn tremendous attention for microelectronic devices. Ta2O5 thin film is deposited on p-type silicon substrate using radio frequency sputtering deposition technique for high-k dielectric applications. The as-deposited films undergo post-deposition annealing treatment at temperatures ranging from 600 °C to 900 °C for 1 h in air ambient. X-ray diffraction analysis revealed the formation of a polycrystalline orthorhombic β – Ta2O5 structure in the annealed films. The RMS roughness of the film is found to be increased from 2.3 nm to 3.7 nm with the increase in annealing temperature to 900 °C. Metal–oxide–semiconductor (Al/Ta2O5/p-Si) structures are fabricated using thermal evaporation for electrical characterizations. The capacitance-voltage (at 1 MHz) of this structure is measured for the sweep voltage from − 4 V to + 4 V. The oxide charge density and interface charge density of the film have been calculated from the C-V curve and found to decrease with the increase in annealing temperature. The highest dielectric constant value of 24.5 at 1 MHz is found for film annealed at 800 °C. The leakage current is measured from the current-voltage measurement and found to be minimum for the film annealed at 800 °C. [ABSTRACT FROM AUTHOR]

Magnetostrictive bimorphs consisting of positive and negative magnetostrictive materials such as FeGa and Ni respectively were made in the form of (a) multilayers containing Si/Ni/FeGa and (b) stacking consisting of Ni/Si/FeGa by sputtering technique on Si substrates. While the thickness of the FeGa film was maintained at 200 nm for all the films, Ni films were grown with two different thicknesses, viz., 100 and 200 nm. Magnetostrictive response of these bimorphs was compared with FeGa unimorph deposited on Si. Structural studies indicated FCC and BCC structure for Ni and FeGa films respectively. Magnetization studies showed a decrease in saturation magnetization with increase in Ni content owing to the lower magnetization of Ni when compared to FeGa. Considerable enhancement in tip deflection has been observed in the bimorph structure when compared with pure FeGa film. [ABSTRACT FROM AUTHOR]

The mechanical performance of protective coatings is crucial in daily industrial environments, with transition metal nitrides being among the most commonly used hard coatings for machining tool protection. However, determining their elastoplastic properties via conventional methods can be challenging due to the thickness‐dependent response of film/substrate systems. In this study, we utilised two sputtering Ti‐Al‐N films as a model hard thin film/soft substrate system to showcase an alternative methodology to the Oliver and Pharr method. This alternative approach involves determining Young's modulus, yield stress and hardness through indentation stress–strain curves obtained from nanoindentation tests, effectively decreasing the substrate's contribution. This decrease was corroborated by finite element simulations conducted on films with thickness below 1.0 μm. The elastoplastic properties determined using our methodology fell within the range reported for typical Ti‐Al‐N films. Furthermore, by applying our methodology, we were able to correlate and discuss the observed differences in mechanical behaviour between the two films based solely on their microstructural, compositional and morphological properties. Thus, we have demonstrated a viable alternative methodology to address substrate contribution challenges in the mechanical characterisation of thin film/substrate systems when employing an indenter with a large radius of curvature (~650 nm). This research holds potential implications for the design of protective submicrometric films with industrial applications. [ABSTRACT FROM AUTHOR]

We report on the structure and dielectric properties of ternary A6B2O17 (A = Zr; B = Nb, Ta) thin films and ceramics. Thin films are produced via sputter deposition from dense, phase‐homogenous bulk ceramic targets, which are synthesized through a reactive sintering process at 1500°C. Crystal structure, microstructure, chemistry, and dielectric properties are characterized by X‐ray diffraction and reflectivity, atomic force microscopy, X‐ray photoelectron spectroscopy, and capacitance analysis, respectively. We observe relative permittivities approaching 60 and loss tangents <1 × 10−2 across the 103–105 Hz frequency range in the Zr6Nb2O17 and Zr6Ta2O17 phases. These observations create an opportunity space for this novel class of disordered oxide electroceramics. [ABSTRACT FROM AUTHOR]

Large-area electrochromic films with high stability under high temperatures and humid conditions are essential for the commercialization of smart windows. In this paper, we introduce a new cathodic coloration Nb 18 W 16 O 93 thin film produced using sputtering that exhibits excellent electrochromic modulation, superior chemical stability, and cyclic durability owing to its stable host structure for ion intercalation. The electrochemical properties of the as-grown Nb 18 W 16 O 93 thin films, including charge density and transmittance modulation, were enhanced with increasing deposition temperatures. The annealed Nb 18 W 16 O 93 thin films (grown at room temperature) exhibited comparable electrochromic performances to films grown at high temperatures. Electrochromic devices composed of annealed and high-temperature-grown Nb 18 W 16 O 93 thin films exhibited excellent durability and nearly identical transmittance modulation, even after 10,000 test cycles. Furthermore, degradation of the surface morphology of the Nb 18 W 16 O 93 thin films after etching in heated water was alleviated, suggesting high stability under hot and humid conditions, whereas the flat surface of the room-temperature-grown WO 3 thin films degraded significantly. [ABSTRACT FROM AUTHOR]

Niobium-based oxides have garnered increased attention in recent years for their remarkable enhancement of corrosion resistance, as well as biofunctional properties of various metallic materials, including 316L SS. However, the mechanical properties of these promising coatings have not been fully elucidated. This study investigated how much the environmental conditions (air, artificial saliva, and NaCl solution) impact the wear performance of 316L SS without and with Nb2O5 coatings deposited via the reactive sputtering technique. The results exhibited a notable decrease in friction coefficient (55% in air, 18% in artificial saliva, 10% in 0.9 wt% NaCl solution), wear area (46% in air, 36% in AS, 17.5% in 0.9 wt% NaCl solution), and wear rate (44.0% in air, 19.5% in AS, 12.0% in 0.9 wt% NaCl solution). Ultimately, the results obtained in the present study elucidate the synergistic mechanisms of corrosion and wear in 316L SS containing Nb2O5 coatings, highlighting its significant potential for applications in the biomedical sector. [ABSTRACT FROM AUTHOR]

Titanium carbo-nitride (TiCN) comes under the metal nitride group which can provide a combined property of titanium carbide (TiC) and titanium nitride (TiN) coating. TiCN Coating possess an excellent mechanical and tribological, properties which leads its application in many industries particularly in the Automotive and aerospace industries. TiCN films can be very hard and strong based on the composition and synthesis process. Physical Vapor Deposition (PVD) technique is widely used for the preparation of thin film coating because of its ability to precisely control the composition and thickness of the coatings. The properties of the developed coating significantly affect by the PVD process parameters and their levels. Multi-Criteria Decision Making (MCDM) methods are widely used in many sectors for the selection of process parameters based upon some specific criteria. In the present work TiCN coatings were synthesized by using one of the most widely used PVD method called magnetron sputtering. L16 orthogonal array was used as a design of experiment for the experimental work by varying the sputtering process parameters like bias voltage, N2 flow rate and substrate to target distance. After the synthesis, the developed films were tested using atomic force microscopy (AFM), Scanning electron microscopy (SEM), and Nanoindentation. From the characterization three response parameters such as hardness (H), Modulus of elasticity (E) and surface roughness (Ra) of the coating has been considered. A hybrid method based on improved removal effects of criteria- technique for order performance by similarity to ideal solution (MEREC-TOPSIS) approach has been considered for the for the process parameters selection. The results have also been compared with other weight calculation techniques. In all the cases it is observed that experiment no 16 and 15 have got the 1st and second rank respectively. However, experiment no 1 is the last rank in all the cases. From the correlation analysis it is found a strong positive correlation between MEREC-TOPSIS and other methods. The method provides a significant advancement in the selection of optimal parameters, ensuring enhanced coating properties crucial for industrial applications [ABSTRACT FROM AUTHOR]

In this study, titanium metal (99.99%) was deposited on quartz glass substrate test specimens by DC magnetron sputtering. Thereafter, radio-frequency magnetron sputtering was used to create an oxide layer of ITO:Ga (97.3 at%) to form a final dual-layer transparent and conductive film on the glass substrate. The film was then annealed at different temperatures under vacuum. The thermal energy rearranged the internal crystalline structure, and this reduced the number of crystalline defects. The multilayer structure of the dual-layer film was explored after annealing: the film thickness, electrical properties, transmission properties, surface structure, grain size, and quality factors were all analyzed. The results showed that the electrical properties of ITO:Ga/Ti improved after annealing at 500 °C (100 W; 30 min) and that the resistivity was 6.51 × 10-4 O·cm. The average penetration of ITO:Ga/Ti after annealing at 400 °C was 87.52%, and after annealing at 500 °C, it was 89.70%. The figure of merit was the optimal value of 4.78 × 10-3 O-1 after annealing at 500 °C. [ABSTRACT FROM AUTHOR]

This paper reports the systematic study on the structure, magnetic properties and magnetoelastic properties for the Fe100− x Ga x (001) thin films epitaxially grown on the different substrates of GaAs(001) and MgO(001) using the sputtering technique. The alloy composition dependence of effective magnetoelastic coupling coefficient B eff along the FeGa [110] direction indicated that the largest magnetoelastic coupling was obtained for the Fe–Ga layer with x = 30 grown on the MgO substrate, which was evaluated to be B eff = − 9.4 × 107 erg cm−3. Considering the results of structural analysis and magnetization measurement, the different crystallite sizes depending on the kind of substrate may give rise to the different magnetoelastic coupling strengths between the Fe–Ga layers on the MgO and the GaAs. The magnetostriction along the Fe–Ga [111] direction λ 111 was also estimated with the assumption of plausible elastic property of Fe–Ga, and showed the values comparable to the reported value of bulk Fe–Ga. This means the large magnetostriction can be obtained even for the Fe–Ga thin films epitaxially grown not only on the GaAs(001) but also on the MgO(001). The findings in this work will give a guideline for designing spintronic applications with a Fe–Ga layer exhibiting a large magnetoelastic coupling. [ABSTRACT FROM AUTHOR]

The evolution of Sb2Se3 heterojunction devices away from CdS electron transport layers (ETL) to wide bandgap metal oxide alternatives is a critical target in the development of this emerging photovoltaic material. Metal oxide ETL/Sb2Se3 device performance has historically been limited by relatively low fill factors, despite offering clear advantages with regards to photocurrent collection. In this study, TiO2 ETLs are fabricated via direct current reactive sputtering and tested in complete Sb2Se3 devices. A strong correlation between TiO2 ETL processing conditions and the Sb2Se3 solar cell device response under forward bias conditions is observed and optimized. Numerical device models support experimental evidence of a spike‐like conduction band offset, which can be mediated, provided a sufficiently high conductivity and low interfacial defect density can be achieved in the TiO2 ETL. Ultimately, a SnO2:F/TiO2/Sb2Se3/P3HT/Au device with the reactively sputtered TiO2 ETL delivers an 8.12% power conversion efficiency (η), the highest TiO2/Sb2Se3 device reported to‐date. This is achieved by a substantial reduction in series resistance, driven by improved crystallinity of the reactively sputtered anatase‐TiO2 ETL, whilst maintaining almost maximum current collection for this device architecture. [ABSTRACT FROM AUTHOR]

Optimizing both performance and stability under varying relative humidity (RH) conditions is crucial for proton exchange membrane fuel cells (PEMFCs). Therefore, effective management of mass transfer and water is an essential key factor. To further improve performance and stability, this paper reports a novel PEMFC design strategy that introduces carbon nanotube (CNT) sheets with titanium (Ti) deposited onto them as an additional functional layer using the sputtering method. The Ti‐CNT (as Ti‐deposited CNT is abbreviated to Ti‐CNT) sheets are inserted between the catalyst layer (CL) and the gas diffusion layer (GDL). This exhibit enhances performance across all testing conditions (25‐100% RH), which is attributed to their optimal pore structure and hydrophilic properties. It shows up to ≈94% higher power density and ≈60% improvement in charge transfer resistance compared to conventional. Moreover, stability tests conducted under a constant voltage demonstrated that this innovative design strategy significantly reduced degradation, thereby proving its superior stability. This novel design strategy of inserting Ti‐CNTs as a functional layer improves electrochemical performance and stability. [ABSTRACT FROM AUTHOR]

This study was focused on unraveling the close dependence of the structural, morphological, and thermoelectric properties of sputtered ZnO films on base pressure. The ZnO film deposited at an optimized base pressure of 5 × 10−6 torr exhibited the highest thermoelectric power factor of 374.6 μW/mK2, corresponding to an electrical conductivity of 265 S/cm and a Seebeck coefficient of −124 μV/K at 583 K. The obtained results revealed that the positive effect of base pressure on enhancing thermoelectric properties of ZnO films is attributed to point-defect modification, including zinc vacancies, singly-, and doubly-charged oxygen vacancies. Based on these results, we propose that defect engineering is a facile and effective approach for improving the thermoelectric behavior of ZnO films, even without doping by controlling the sputtering conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

Thin films are the backbone of the electronics industry, and their widespread application in heat sensors, solar cells, and thin-film transistors has attracted the attention of researchers. The current study involves the deposition of a hetero-structured (ZnO/Zn/ZnO) thin film on a well-cleaned glass substrate using the DC magnetron sputtering technique. The samples were then annealed at 100, 200, 300, 400, and 500 °C. The structural, morphological, and electrical characteristics of the annealed samples as well as one as-deposited sample were then examined using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and a Hall effect measuring apparatus. XRD analysis showed a hexagonal ZnO crystal structure for the samples annealed at 300 and 400 °C, whereas the samples annealed at 100 and 200 °C showed metallic zinc and hexagonal ZnO, and the crystallinity decreased for the sample annealed at 500 °C with pure hexagonal crystal symmetry. According to the AFM study, as the annealing temperature increases, the average roughness (Ra) decreases. Temperature has an inverse relationship with particle size. The optimal annealing temperature was determined to be 400 °C. Over this temperature range, the average roughness and particle size increased. Similarly, when Ra decreased, the conductivity increased and the resistance decreased. A fundamental difficulty is that the heating of the heterostructure to 400 °C melts the Zn-based intermediate layer, which alters the Zn phase and disrupts the sample homogeneity. [ABSTRACT FROM AUTHOR]

In this study, the effect of annealing and substrate conditions on the ferroelectricity of undoped hafnium oxide (HfO2) was analyzed. Hafnium oxide was deposited on various substrates such as platinum, titanium nitride, and silicon (Pt, TiN, Si) through RF magnetron sputtering. Annealing was performed in a nitrogen atmosphere at temperatures ranging from 400 to 600 °C, and the process lasted anywhere from 1 to 30 min. As a result, it was confirmed that the orthorhombic phase, the main cause of ferroelectricity, was dominant after a post-anneal at 600 °C for 30 min. Additionally, it was observed that interface mixing between hafnium oxide and the substrate may degrade ferroelectricity. Accordingly, the highest remanent polarization, measured at 14.24 μC/cm2, was observed with the Pt electrode. This finding was further corroborated by piezo force microscopy and endurance tests, with the results being significant compared to previously reported values. This analysis demonstrates that optimizing substrate and annealing conditions, rather than doping, can enhance the ferroelectricity of hafnium oxide, laying the foundation for the future development of ferroelectric-based transistors. [ABSTRACT FROM AUTHOR]

Ternary and quaternary compounds offer vast potential for tailoring material properties through compositional adjustments and complex interactions among their constituent elements. However, many of their compositional possibilities still need to be investigated. Energy-dispersive X-ray spectroscopy (EDX) is crucial for determining elemental composition but is inadequate for identifying chemical bonds and physical properties. This work introduces a novel methodology using a stoichiometric deviation vector (SDV) to estimate the physical and compositional feature characteristics of Si, N, and O compounds by comparing actual molar ratios with ideal stoichiometric references. We validated this method by estimating Si-O bonds in silicon oxynitride samples, demonstrating strong agreement with FTIR and refractive index results. We also extended our proof of principle for SiAlON compounds and established an adaptable procedure to analyze compounds with more than three elements. This flexible methodology will significantly value the materials research community, providing valuable compositional features and physical insights by performing elemental EDX characterizations. [ABSTRACT FROM AUTHOR]

Thin film solar cells are gaining popularity as an affordable, efficient, and flexible substitute for traditional silicon solar cells . This success is closely tied to the deposition techniques used to fabricate their layers. This review explores and analyzes the advances in the major deposition techniques for solar cell applications, offering insights into their underlying principles, associated advantages, drawbacks, and suitability for diverse materials and device architectures. The two primary deposition for thin film solar cells are PVD and CVD. In PVC materials are physically ejecting from a target, and depositing it onto a substrate. While, CVD entails the reaction of gases or vapour precursors to creating film on a substrate. The ability to achieve high purity, control over film properties, scalability, and compatibility with flexible substrates are notable advantages. However, challenges such as high costs and complexity can impact the commercial viability of certain techniques. Recent advancements in the technology of thin film deposition for solar cells include the discovery of novel materials with enhanced light absorption and electronic charge transport capabilities, emerging deposition processes such as pulsed laser deposition, and atomic layer deposition scalable and low-cost processes like roll-to-roll processing, and integration with other technologies like perovskite solar cells and tandem devices. Understanding these techniques and staying informed about recent advancements and future directions empowers researchers and engineers to innovate and create improved thin film solar cells, contributing significantly to a more sustainable future through enhanced solar energy harvesting technologies. [ABSTRACT FROM AUTHOR]

In this study, we examined the fatigue crack nucleation and propagation mechanisms of an AlSi sputtered thin film subjected to the quasistatic tensile test and cyclic loading test by scanning electron microscopy. An AlSi thin film with 1.0 wt% Si was prepared by dc magnetron sputtering at a substrate temperature of 260 ℃, followed by annealing at 490 ℃. Two types of uniaxial tensile test equipment were prepared, namely, manual tensile loading equipment and automatic tensile loading equipment. The combination of the use of manual-type equipment and electron backscattered diffraction analysis enabled us to visualize crystal grain subdivision mechanisms. The automatic-type equipment enabled us to understand fatigue crack propagation mechanisms in the AlSi thin film after crack nucleation originating from grain subdivision. A fatigue crack propagated in a zigzag manner under the low stress amplitude condition during the fatigue test, whereas it propagated straightly under the high stress amplitude condition. This phenomenon is discussed from the viewpoints of crack detouring around Si segregates and Si brittleness. [ABSTRACT FROM AUTHOR]

Ternary and quaternary compounds offer vast potential for tailoring material properties through compositional adjustments and complex interactions among their constituent elements. However, many of their compositional possibilities still need to be investigated. Energy-dispersive X-ray spectroscopy (EDX) is crucial for determining elemental composition but is inadequate for identifying chemical bonds and physical properties. This work introduces a novel methodology using a stoichiometric deviation vector (SDV) to estimate the physical and compositional feature characteristics of Si, N, and O compounds by comparing actual molar ratios with ideal stoichiometric references. We validated this method by estimating Si-O bonds in silicon oxynitride samples, demonstrating strong agreement with FTIR and refractive index results. We also extended our proof of principle for SiAlON compounds and established an adaptable procedure to analyze compounds with more than three elements. This flexible methodology will significantly value the materials research community, providing valuable compositional features and physical insights by performing elemental EDX characterizations.

4-probe measurements of surface resistivity, measurements of dark and light current-voltage characteristics, the possibilities of using a thin PdSi film to obtain perfect nano-sized ohmic contacts on the Si(111) surface have been investigated using Auger electron spectroscopy methods in combination with ion etching of the surface. It has been shown that the depth of Ni diffusion in the Ni-Si (111) system is 400 ‑ 500 Å at indoor temperature, and 70 – 80 Å in the Ni-PdSi-Si (111) system. The quality of the ohmic contact in the latter case does not change up to T = 800 K and withstands luminous flux illumination up to F = 1100 lux. It is shown that the resistivity of the PdSi film passes through a minimum at T = 900 – 1000 K. An analysis of the results obtained will be given in the article.

Abstract Pioneering flexible micro-supercapacitors, designed for exceptional energy and power density, transcend conventional storage limitations. Interdigitated electrodes (IDEs) based on laser-induced graphene (LIG), augmented with metal-oxide modifiers, harness synergies with layered graphene to achieve superior capacitance. This study presents a novel one-step process for sputtered plasma deposition of HfO2, resulting in enhanced supercapacitance performance. Introducing LIG-HfO2 micro-supercapacitor (MSC) devices with varied oxygen flow rates further boosts supercapacitance performance by introducing oxygen functional groups. FESEM investigations demonstrate uniform coating of HfO2 on LIG fibers through sputtering. Specific capacitance measurements reveal 6.4 mF/cm2 at 5 mV/s and 4.5 mF/cm2 at a current density of 0.04 mA/cm2. The LIG-HfO2 devices exhibit outstanding supercapacitor performance, boasting at least a fourfold increase over pristine LIG. Moreover, stability testing indicates a high retention rate of 97% over 5000 cycles, ensuring practical real-time applications.

Abstract Matching of various chalcogenide films shows the advantage of delivering multilayer heterostructures whose physical properties can be tuned with respect to the ones of the constituent single films. In this work, (Ge–Sb–Te)-based heterostructures were deposited by radio frequency sputtering on Si(100) substrates and annealed up to 400 °C. The as-deposited and annealed samples were studied by means of X-ray fluorescence, X-ray diffraction, scanning transmission electron microscopy, electron energy loss spectroscopy and Raman spectroscopy. The heterostructures, combining thermally stable thin layers (i. e. Ge-rich Ge5.5Sb2Te5, Ge) and films exhibiting fast switching dynamics (i. e. Sb2Te3), show, on the one side, higher crystallization-onset temperatures than the standard Ge2Sb2Te5 alloy and, on the other side, none to minimal Ge-segregation.

The evolution of a multilayer sample surface during focused ion beam processing was simulated using the level set method and experimentally studied by milling a silicon dioxide layer covering a crystalline silicon substrate. The simulation took into account the redeposition of atoms simultaneously sputtered from both layers of the sample as well as the influence of backscattered ions on the milling process. Monte Carlo simulations were applied to produce tabulated data on the angular distributions of sputtered atoms and backscattered ions.Two sets of test structures including narrow trenches and rectangular boxes with different aspect ratios were experimentally prepared, and their cross sections were visualized in scanning transmission electron microscopy images. The superimposition of the calculated structure profiles onto the images showed a satisfactory agreement between simulation and experimental results. In the case of boxes that were prepared with an asymmetric cross section, the simulation can accurately predict the depth and shape of the structures, but there is some inaccuracy in reproducing the form of the left sidewall of the structure with a large amount of the redeposited material.To further validate the developed simulation approach and gain a better understanding of the sputtering process, the distribution of oxygen atoms in the redeposited layer derived from the numerical data was compared with the corresponding elemental map acquired by energy-dispersive X-ray microanalysis.

The paper describes a simple analytical model that allows the calculation of hydrogen surface coverage under the influence of several processes that can co-occur during the ion-beam bombardment/sputter analysis of a sample surface, in particular during analysis by secondary ion mass spectrometry (SIMS). The model considers processes of dissociative adsorption, desorption, absorption from the surface into the sample volume, and removal by ion bombardment. After describing the model, we provide some examples of its practical applications for interpretation of the experimental results obtained during in situ SIMS studies of hydrogen interaction with the hydrogen-storage alloys TiFe, Zr2Fe, and with nickel. In the examples, some quantitative characteristics of surface-related processes involving hydrogen, such as hydrogen sputtering rate, activation energy of hydrogen desorption and absorption, have been successfully determined using various model approaches.

Herein, a localized surface plasmon resonance‐based sensor for volatile organic compounds (VOCs) detection is developed. The sensors are fabricated as a hybrid nanostructure of gold nanoparticles coated with a tantalum oxide (TaO) thin film on a glass slide substrate through magnetron sputtering and thermal solid‐state dewetting techniques. The thickness of the TaO film varies between 10 and 70 nm. The optical properties of samples are characterized by UV‐Vis‐NIR spectrophotometry, while their morphologies are confirmed via transmission electron microscopy. The results show the shift of the minimum optical transmittance related to the TaO thickness. Electrical field simulations are performed to predict the sensitivity of the prepared samples for VOCs detection. In addition, the sensors are tested with different VOCs, including formaldehyde, isopropanol, acetone, and methanol, which show good potential for practical applications. [ABSTRACT FROM AUTHOR]

NiTi alloys are actively used in medicine as implants because of their mechanical properties. At the same time, however, the NiTi surface is not biologically active, which has a negative effect on osteogenesis. In addition, Ni is capable of causing various toxic reactions in the human body. It is therefore necessary to create a composite coating that is both bioactive and prevents the release of Ni ions. It has been shown that by changing the modes of plasma assisted RF sputtering of a calcium phosphate target, it is possible to obtain coatings with different contents of the amorphous phase. The coatings formed consist of hydroxyapatite and amorphous calcium phosphate. On the surface of a sample not treated with argon plasma, there are no phases containing calcium or phosphorus, although these elements are present on the surface. The different ways in which the CaP coatings were applied also affected their structure. It was found that the CaP coatings of samples M2 and M3 have mediocre corrosion resistance, dissolving quickly. This has a positive effect on the ability to osteogenesis, which was discovered as a result of in vitro tests. These tests have shown that the sample obtained at I discharge = 30 A and U bias = 30 V has the highest bioactivity and produces the lowest percentage of dead cells. [ABSTRACT FROM AUTHOR]

Featured Application: This work could be applied for producing self-cleaning solar mirrors. In this study, a low-cost, scalable and robust process is proposed as an innovative method for coating solar mirrors with a self-cleaning, transparent in the full solar range and versatile material based on auxetic aluminum nitrides, previously obtained at the laboratory scale. This work presents the scaling-up of the fabrication process from the laboratory to prototypal scale and the preliminary results of outdoor self-cleaning solar mirror field tests in the demonstrative concentrating solar power (CSP) plant ENEASHIP located in Casaccia (Rome) ENEA Research Center. Prototypes with a size of 50 × 40 cm have shown stability in external conditions: no coating degradation occurred during the test campaign. Their washing restores the initial reflectance affected by soiling and the self-cleaning performance allows for the utilization of a reduced quantity of water for cleaning operations with respect to the uncoated glass of back surface mirrors. A similar self-cleaning AlN coating could be utilized on other solar components affected by soiling, such as the glass envelopes in heat-collecting elements, PV panels and other parts where a self-cleaning performance combined with an optical one is required. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) is a modern developing group of technologies based not on material removal, but on the layer-by-layer growth and synthesis of an object according to a CAD (computer-aided design) model. The main disadvantages of objects manufactured by AM technologies are a high degree of porosity and surface roughness. This study examines the possibility of modifying the surface of additive materials Ti Al V and AlSi Mg by irradiation with Ar ions with energies ranging from 2 to 9 keV. Using SEM, the surface topography was obtained before and after irradiation and mechanical polishing. A reduction in surface porosity and roughness was demonstrated, as well as the influence of beam energy on the final surface topography. [ABSTRACT FROM AUTHOR]

The temperature dependences of the sputtering of negative ions of silicon–oxygen clusters are studied for the first time by the method of ultrahigh-vacuum secondary ion mass spectrometry. In the temperature range of 100–200°C, an increase in the yield of negative ion clusters of silicon suboxide and dioxide is observed, while after a maximum at 200°C and up to 800°C the yield decreases exponentially. At 800°C, the yield of silicon oxide clusters stops while the desorption of suboxide is still observed. The yields of negative oxygen ions correlate with the temperature dependences of the yield of silicon–oxygen clusters and indicate the presence of oxygen adsorbed on the surface and dissolved in the bulk of the silicon crystal. In this work, for the first time, to assess the contribution of these processes a signal from negatively charged silicon dimers, which are an adsorbed silicon atom on a silicon atom located at a substrate lattice site, is used. The temperature dependence of the thermal desorption of negatively charged silicon trimers is measured. In our opinion, this signal is due to a decay negative cluster ion of a surface defect center, the so-called Pb-center, of an adsorbed silicon tetramer—three silicon atoms on the surface closed at the top by an additional silicon atom. [ABSTRACT FROM AUTHOR]

We investigate the processes of microrelief formation on a Si(100) surface under irradiation with a Ga+-ion beam with an energy of 30 keV and a fluence of D = 1.25 × 1018–2 × 1019 cm–2 at incident angles of θ = 30°–85°. Within the angular range of θ = 40°–70°, a faceted wavy relief forms on the Si surface, while at θ = 30°, a sinusoidal relief develops. An experimental dependence of the periodic structure wavelength as a function of irradiation time λ(t) ~ t n, where n = 0.33–0.35, is obtained. The average values of relief propagation velocities and their direction relative to the incident ion direction are determined for θ = 30° and 40°, amounting to –5.3 ± 0.6 and –6.3 ± 0.6 nm s–1, respectively. The results are discussed in detail within the framework of existing models of wavelike surface relief formation under ion bombardment. [ABSTRACT FROM AUTHOR]

The study investigated the biological properties of a composite material composed of poly(lactide) (PLA) and iron (Fe) produced by sputtering iron onto melt-blown poly(lactide) nonwoven fabrics. The research aimed to thoroughly understand the structure and properties of these materials and their potential applications in biomedicine. We conducted comprehensive chemical and structural analyses using techniques such as microscopic analysis, flame atomic absorption spectrometry (FAAS), and Brunauer–Emmett–Teller (BET) surface area analysis to precisely determine the properties of PLA-Fe materials. Additionally, we evaluated their impact on blood coagulation processes by measuring activated partial thromboplastin time (aPTT) and prothrombin time (PT). We also performed biological analyses on human peripheral blood mononuclear cells (PBM cells) including cell viability and DNA damage. Our results clearly demonstrate that PLA-Fe materials do not significantly influence blood coagulation mechanisms, as they only slightly prolong aPTT time and have no effect on PT. This suggests their potential in biomedical applications. Our results indicate the absence of cyto- and genotoxic properties of PLA-Fe materials against normal blood cells. In conclusion, the research findings suggest that the novel poly(lactide) and iron-sputtered nonwoven fabrics are promising tools in the field of biomedicine, offering potentially innovative therapeutic solutions for the treatment of wounds and injuries. [ABSTRACT FROM AUTHOR]

Surface side reactions and time‐consuming modification methods hinder the practical application of zinc‐ion batteries. This study introduces an ultrathin protection layer for the Zn anode via a rapid sputtering method. The dopants on the CN10@Zn anode create surface dipoles and local variations in charge distribution, facilitating zinc ion migration to pyrrolic nitrogen dopant sites with reduced adsorption barriers. Additionally, hydroxyl oxygen dopants enhance the hydrophilicity of the sputtering layer, forming a strong adhesion with the zinc anode and improving ion accessibility. This results in dense nucleation sites for uniform zinc deposition. Consequently, the sputtered layer achieves a Coulombic efficiency of 99.8% over 2,700 cycles in Cu||Zn cells and a lifespan of up to 2,100 h in zinc symmetric cells. When paired with Na0.65Mn2O4 cathodes, the sputtered layer retains 89% capacity over 1,000 cycles at 1 A g−1. This study presents a promising method for rapidly fabricating ultrathin electrode materials. [ABSTRACT FROM AUTHOR]

Pioneering flexible micro-supercapacitors, designed for exceptional energy and power density, transcend conventional storage limitations. Interdigitated electrodes (IDEs) based on laser-induced graphene (LIG), augmented with metal-oxide modifiers, harness synergies with layered graphene to achieve superior capacitance. This study presents a novel one-step process for sputtered plasma deposition of HfO2, resulting in enhanced supercapacitance performance. Introducing LIG-HfO2 micro-supercapacitor (MSC) devices with varied oxygen flow rates further boosts supercapacitance performance by introducing oxygen functional groups. FESEM investigations demonstrate uniform coating of HfO2 on LIG fibers through sputtering. Specific capacitance measurements reveal 6.4 mF/cm2 at 5 mV/s and 4.5 mF/cm2 at a current density of 0.04 mA/cm2. The LIG-HfO2 devices exhibit outstanding supercapacitor performance, boasting at least a fourfold increase over pristine LIG. Moreover, stability testing indicates a high retention rate of 97% over 5000 cycles, ensuring practical real-time applications. [ABSTRACT FROM AUTHOR]

Matching of various chalcogenide films shows the advantage of delivering multilayer heterostructures whose physical properties can be tuned with respect to the ones of the constituent single films. In this work, (Ge–Sb–Te)-based heterostructures were deposited by radio frequency sputtering on Si(100) substrates and annealed up to 400 °C. The as-deposited and annealed samples were studied by means of X-ray fluorescence, X-ray diffraction, scanning transmission electron microscopy, electron energy loss spectroscopy and Raman spectroscopy. The heterostructures, combining thermally stable thin layers (i. e. Ge-rich Ge5.5Sb2Te5, Ge) and films exhibiting fast switching dynamics (i. e. Sb2Te3), show, on the one side, higher crystallization-onset temperatures than the standard Ge2Sb2Te5 alloy and, on the other side, none to minimal Ge-segregation. [ABSTRACT FROM AUTHOR]

4-probe measurements of surface resistivity, measurements of dark and light current-voltage characteristics, the possibilities of using a thin PdSi film to obtain perfect nano-sized ohmic contacts on the Si(111) surface have been investigated using Auger electron spectroscopy methods in combination with ion etching of the surface. It has been shown that the depth of Ni diffusion in the Ni-Si (111) system is 400 - 500 Å at indoor temperature, and 70 – 80 Å in the Ni-PdSi-Si (111) system. The quality of the ohmic contact in the latter case does not change up to T = 800 K and withstands luminous flux illumination up to F = 1100 lux. It is shown that the resistivity of the PdSi film passes through a minimum at T = 900 – 1000 K. An analysis of the results obtained will be given in the article. [ABSTRACT FROM AUTHOR]

Aluminum‐doped zinc oxide Al:ZnO (AZO) is a non‐toxic material applied as a transparent conductive oxide film. In this study, we report on the structural, optical, and electrical properties of AZO films obtained by thermally oxidizing aluminum‐doped Zn films produced by a versatile and low‐cost method of doping using the magnetron sputtering technique deposition. We use aluminum wire above the zinc target to produce Al:Zn films. The influence of r.f. power and different Al wire lengths on the AZO film properties were studied. The resulting AZO films exhibited Al concentrations of up to 2.85% and an optical gap between 3.22 and 3.29 eV. The transmittance was greater than 80% for all samples, and the electrical resistivity decreased by two orders of magnitude with Al doping. As a result, the sample with an aluminum concentration of approximately 1% had the lowest resistivity. In this work, it was possible to relate the lower resistivity with larger grain size and smaller concentrations of defects or vacancies. [ABSTRACT FROM AUTHOR]

At the focus of our investigation lies the precision fabrication of ultrathin platinum–gadolinium (PtGd) alloy films, with the aim to use these films for resistive hydrogen gas sensing. The imperative for sensitive and selective sensors to harness hydrogen's potential as an alternative energy source drives our work. Applying rare earth materials, we enhance the capabilities of hydrogen gas sensing applications. Our study pioneers PtGd alloy thin films for hydrogen gas sensing, addressing a gap in existing literature. Here, we demonstrate the functional characteristics of 2 nm thick PtxGd100′x (x = 25, 50 and 75) alloy films, analyzing their hydrogen gas sensing properties, comprehensively examining the interplay between alloy composition, temperature fluctuation and hydrogen concentration. The effect of composition and structural properties on the sensing response were assessed using EDX and XPS. The films are tested at a temperature range between 25 °C and 150 °C with hydrogen gas concentrations ranging from 10 ppm to 5%. Hydrogen gas sensing mechanisms in PtGd alloy ultrathin films are explained by surface scattering. The unique combination of Pt and Gd offers promising characteristics for gas sensing applications, including high reactivity with hydrogen gas and tunable sensitivity based on the alloy composition. [ABSTRACT FROM AUTHOR]

This paper portrays the effect of growth rate on the structural, magnetic, and electrical properties of sputtered Ni thin films. Seventy-five nanometer thick Ni films were grown on Si <100> substrates at room temperature by high power impulse magnetron sputtering with varying growth rates such as 0.27, 0.57, 1.01, 2.18, and 2.65 Å/s. All the films crystallized in a single FCC type structure devoid of any impurity phase. With an increase in the growth rate, the density of the Ni films was found to increase. The surface roughness and the stresses developed in Ni films were found to decrease with an increase in the growth rate. Microstructural investigations indicated an island of surface morphology for all the films. An increase in growth rate was also found to affect the magnetic properties of Ni thin films considerably. Saturation magnetization increased with an increase in growth rate both along the in-plane and out-of-direction owing to the increase in the density of the film and reduction in stresses and surface roughness. Further, the in-plane magnetization studies also showed an increase in in-plane magnetic anisotropy in Ni films with an increase in growth rate. Evidences for improvement in the in-plane magnetic anisotropy were derived from the increase in the in-plane coercivity and remanence. Temperature variation of electrical resistivity in Ni films indicated a metallic behavior. Films grown at higher growth rates exhibited high-temperature co-efficient of resistance suitable for resistance temperature detector applications. [ABSTRACT FROM AUTHOR]

Chromium‐based coatings have been of interest to researchers for the last two decades because of their extraordinary properties like high hardness, high wear, and corrosion resistance properties. However, it is in practice and research to increase the properties of Cr‐based coatings for high‐temperature applications. Numerous dopants like silicon (Si), titanium (Ti), vanadium (V), aluminum (Al), and zirconium (Zr) have been used together with Cr to achieve enhanced properties. The plasma‐based sputtering process is one of the popular and reliable techniques to deposit thin film coatings. The substrate material, processed gas and pressure, substrate temperature, film thickness, and so on also play a significant role in varying the properties and microstructure of the deposited film. Several researchers have deposited Cr/CrN‐based thin films via the chemical vapor deposition technique (CVD) and physical vapor deposition technique (PVD) to study their properties and behavior at room temperature as well as for high‐temperature applications. This work reflects the review of work done to deposit Cr/CrN‐based coatings deposited via PVD: more specifically sputtering technique. The effect of doping in the CrN matrix and variation in sputtering parameters on the properties of CrN‐based coatings have also been studied. [ABSTRACT FROM AUTHOR]

In this study, we used Raman spectroscopy to compare the local structure of Ge2Sb2Te5 (GST) thin films with thicknesses of 90 nm and 271 nm that were crystallized through thermal annealing and laser radiation (laser annealing) during the recording of Raman spectra in situ. We found that for all crystallized films, the position of the main peaks in the Raman spectra was almost the same, and their structure corresponded to a hexagonal close packed state. It is noteworthy that the full width at half maximum (FWHM) of the main peaks varies considerably depending on the crystallization method used. [ABSTRACT FROM AUTHOR]

Thin films of zinc sulfide (ZnS) with varying thicknesses have been successfully fabricated using radio frequency magnetron sputtering on glass substrates at a temperature of 300 K. Structural analysis via X-ray diffraction and selected area electron diffraction confirmed the presence of nanocrystalline cubic ZnS phases in the films. The crystallite size, determined from X-ray diffraction lines, ranged between 42 and 55 nm. We also explored the morphological attributes of these surfaces and observed significant changes in both grain shape and size. Our atomic force microscopy analyses revealed that the thinner film displayed a topography marked by thinner, elongated rough peaks. As the film thickness increased, these rough peaks gradually transformed into wider, flatter features. Additionally, the films exhibited distinct percolation properties, which were undeniably tied to the alterations in the shape and size of the ZnS grains on their surfaces. Thinner samples demonstrated more pronounced surface percolation (FS > 0.5) compared to thicker samples, which displayed reduced surface percolation. Furthermore, we noted that the 250 nm film predominantly showcased strongly multifractal 3D spatial patterns in contrast to the other films. Spectroscopic measurements in the UV–visible-near infrared region revealed high transparency across the 350–850 nm spectra, with a noticeable blue shift in the absorption edge. Calculations yielded direct allowed band gaps within the range of 3.69–3.85 eV. These results indicate that the optical properties of films can be tailored by their structural and morphological characteristics, thereby offering valuable guidance for their appropriate applications. [ABSTRACT FROM AUTHOR]

In this research, CZTS thin films were grown on flexible Cu-foil substrates with varying sulfurization times. Distinct characterization methods were employed, including X-ray diffraction (XRD), Raman spectroscopy, EnergyDispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM), optical transmission, and Photoluminescence (PL) measurements. Distinctive diffraction peaks characteristic of the kesterite CZTS phase were observed in the XRD analysis, occurring around at 2θ= 28.45° (112), 47° (220/204), and 56° (312/116). Additionally, some secondary phases such as Cu2S and SnS were identified. Raman spectroscopy confirmed the presence of the kesterite CZTS phase, with a prominent peak detected at approximately ~336 cm-1, attributed to sulfur atom vibrations within the kesterite structure. Apart from CZTS structure, minor peaks suggesting the presence of the Cu2SnS3 (CTS) phase was detected. EDX analysis revealed compositions with Cu-poor content and Zn-rich content across all samples, with slight variations in sulfurization dwell times affecting the chemical composition. SEM imaging at different magnifications showed alterations in surface morphology and grain structures. Films sulfurized for 30 s and 60 s displayed a granular structure morphology, while extending the dwell time to 120 s resulted in a more compact surface morphology. Optical band gap values ranged between 1.57 and 1.60 eV. PL measurements consistently exhibited strong PL emission around 1.25 eV for all samples, attributed to various transitions within the band structure of CZTS film. The absence of observable band-to-band transitions in the PL measurements indicated the presence of intrinsic defect levels and recombination centers within CZTS. Overall, it was demonstrated in this study that CZTS thin films can be produced on flexible Cu-foils with short sulfurization times, thereby expanding the application areas of CZTS thin-film solar cells. [ABSTRACT FROM AUTHOR]