Search Results (287)

This work presents an approach to water-dispersible polylactide (PLA) particle fabrication and their application in low-temperature film formation using a combination of mechanical dispersion and ultrasonication techniques. Stable PLA dispersions were obtained after removal of surfactant and allowed for thin-film preparation, exhibiting a significantly reduced minimum film formation temperature (MFFT) from 128 °C to 80 °C after reducing the characteristic particle size from ~2.2 µm to ~140 nm. To tailor the interfacial behavior and mechanical flexibility of the resulting coatings, a set of conventional and bio-based plasticizers was evaluated, including epoxidized fatty acids, PEG-400, and several hydrophobic deep eutectic solvents (HDESs) synthesized from menthol and carboxylic acids. Compatibility between PLA and each plasticizer was predicted using Hansen solubility parameters. The efficiency of plasticization was assessed through glass transition temperature suppression in solvent-cast films. The combination of submicron PLA particles and selected plasticizers enabled film formation at temperatures as low as 48 °C, confirming the potential of these systems for energy-efficient coating technologies. Furthermore, composite coatings incorporating micro-sized cellulose fibers (L/D ≈ 10.5–11.5) regenerated from agricultural residues were successfully obtained, demonstrating the feasibility of integrating bio-derived fillers into waterborne PLA formulations. In this study, the use of water-insoluble deep eutectic solvents type plasticizers for PLA coatings from water dispersions was reported for the first time. This establishes a foundation for developing sustainable, low-VOC, and low film formation temperature PLA-based coating materials. Full article

Hydrogenated tetrahedral amorphous carbon (ta-C:H) thin films were modified using 266 nm picosecond laser pulses to investigate structural transformations at low and moderate fluences. Nitrogen-doped hydrogenated tetrahedral amorphous carbon layers 20–40 nm thick were deposited on silicon (Si) and silicon dioxide on silicon (SiO₂/Si) substrates and irradiated with picosecond pulses at 0.5–1.6 J cm⁻² using a raster-scanned beam. Structural changes in morphology, composition, and bonding were evaluated via optical microscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Even below 1.0 J cm⁻², localized color shifts and slight swelling indicated early structural rearrangements without significant material removal. Above 1.0–1.2 J cm⁻², the films were largely ablated, although a persistent 3–6 nm carbon layer remained on both substrate types. XPS showed an increase in sp²-bonded carbon by roughly 15%–20% in optimally modified regions, and Raman spectroscopy revealed defect-activated D-bands and the formation of multilayer defective graphene or reduced-graphene-oxide-like flakes at ablation boundaries. These results indicate that picosecond ultraviolet irradiation enables controllable graphitization and thinning of ta-C:H films while maintaining uniform processing over centimeter-scale areas, providing a route to thin, conductive, partially graphitized carbon coatings for optical and electronic applications. Full article

The rapid commercialization of next-generation photovoltaic (PV) technologies, particularly perovskite, thin-film roll-to-roll (R2R) architectures, and tandem devices, requires robust assessment of environmental performance at the level of industrial manufacturing processes. Environmental impacts can no longer be evaluated solely at the device or module level. Although many life-cycle assessment (LCA) studies compare silicon, cadmium telluride (CdTe), copper indium gallium selenide (CIGS), and perovskite technologies, most rely on aggregated indicators and database-level inventories. Few studies systematically compile and harmonize process-level life-cycle inventories (LCIs) for the manufacturing steps that differentiate emerging industrial routes, such as solution coating, R2R processing, atomic layer deposition, low-temperature annealing, and advanced encapsulation–metallization strategies. In addition, inconsistencies in functional units, system boundaries, electricity-mix assumptions, and scale-up modeling continue to limit meaningful cross-study comparison. To address these gaps, this review (i) compiles and critically analyzes process-resolved LCIs for innovative PV manufacturing routes across laboratory, pilot, and industrial scales; (ii) quantifies sensitivity to scale-up, yield, throughput, and electricity carbon intensity; and (iii) proposes standardized methodological rules and open-access LCI templates to improve reproducibility, comparability, and integration with techno-economic and prospective LCA models. The review also synthesizes current evidence on recycling, circularity, and critical-material management. It highlights that end-of-life (EoL) benefits for emerging PV technologies are highly conditional and remain less mature than for crystalline-silicon systems. By shifting the analytical focus from technology class to manufacturing process and life-cycle configuration, this work provides a harmonized evidence base to support scalable, circular, and low-carbon industrial pathways for next-generation PV technologies. Full article

Antibacterial thin-film coatings are of increasing interest for enhancing hygiene in controlled environments such as commercial greenhouses. Phytopathogens including Pseudomonas syringae, and human pathogens such as Escherichia coli, Micrococcus luteus, and Staphylococcus aureus, frequently contaminate greenhouse environments. The present study aimed to develop and evaluate multifunctional magnetron-sputtered glass coatings with strong antimicrobial performance, deposited by physical vapor deposition to achieve precise control of film composition and uniform coverage of large substrates (≥0.25 m²), ensuring industrial-scale applicability. Thin films were fabricated by magnetron sputtering using multi-alloy targets composed of Cu, Sn, Zn, Al, Ni, Fe, Ti, Mn, Nb, or Co. Fourteen distinct coating compositions were characterized using high-resolution transmission electron microscopy, scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Antibacterial performance was evaluated against the following strains: E. coli (PCM 2560), M. luteus (PCM 525), S. aureus (PCM 2602), and P. syringae pv. tomato (IOR2146). Coatings prepared from 90%Cu-10%Sn, 90%Cu-10%Zn, and 80%Cu-20%Ti targets exhibited one of the highest antibacterial efficiencies. These coatings also showed strong mechanical durability and corrosion resistance. Our results indicate that coatings obtained from Cu-based multi-alloy targets by magnetron sputtering are promising candidates for use as durable, antimicrobial inner glass surfaces in future greenhouse applications. Full article

The fabrication of undoped and aluminium-doped zinc oxide thin films on quartz glass substrates through the aqueous spray method is reported. The prepared aqueous precursor solutions containing Zn²⁺ and varying mole percentages (0, 2, 4, and 8%) of Al³⁺ complexes were spray-coated onto quartz glass substrates preheated at 180 °C. The as-sprayed films obtained were then heat-treated at 450 °C for 30 min in a furnace to produce the various thin films. The structural and optical properties of the resultant thin films were analysed using the X-ray diffractometer (XRD) and ultraviolet–visible (UV-Vis) spectrophotometer. The XRD results revealed that the fabricated thin films have a prominent peak correlating to the (002) Miller index, which is the preferred orientation of the zinc oxide hexagonal wurtzite phase. The fabricated thin films with a film thickness of approximately 189 nm absorb light in the visible region and have a transmittance of over 80% even after being doped with aluminium. The photocatalytic activities of the thin films were evaluated via visible light irradiation of an aqueous methyl orange solution, and the Al-doped ZnO thin films exhibited good photocatalytic activities, which resulted in an increase in the doping mole percentages of aluminium. Full article

Dip-coating and sol–gel techniques are used to apply ZnO sol–gel films to glass substrates. The primary ingredient used to produce the film is zinc acetate dihydrate. The ZnO sample is prepared for 0, 1, 3, 5, 10, 15, and 30 days. To deposit nanocrystalline thin films, several gels are used. The films’ structural and photocatalytic properties are examined in relation to the ZnO solid’s aging time. UV–vis spectroscopy is used to evaluate the catalytic degradation of the antibiotic cefuroxime (CFX) in tap and distilled water, taking into account the initial solution’s aging duration. Every experiment is carried out under ultraviolet light illumination. These findings demonstrate that ZnO’s photocatalytic activity generally prolongs the initial solution. When compared to freshly prepared films, films made from a ZnO sample for 30 days showed the highest photocatalytic degradation of the medication under UV light. Overall, the photocatalytic activity of ZnO is increased by increasing the aging time of the starting solution. All samples and the photocatalytic test findings are reproducible. Full article

SU-8 photoresist is extensively used as a structural and passivation layer in microelectromechanical systems, microfluidic devices, and related microscale technologies. The long-term reliability of these devices critically depends on the mechanical integrity and viscoelastic behaviour of the SU-8 coating. In this study, the mechanical and viscoelastic behaviour of SU-8 polymer thin films was systematically investigated using nanoindentation at different baking stages representative of standard photolithographic processing. SU-8 layers were spin-coated on silicon wafers and subjected to pre-bake, post-bake, and hard-bake treatments to evaluate the effects of progressive cross-linking. Static nanoindentation revealed that the elastic modulus did not change significantly during the baking phases and remained near 6.2 GPa; however, a significant change in hardness was observed from 0.173 ± 0.012 GPa after pre-bake to 0.365 ± 0.011 GPa and 0.364 ± 0.016 GPa after post- and hard bake, respectively. Creep tests analysed by the Burgers viscoelastic model showed a significant increase in both the retarded modulus and viscosity parameters with thermal curing, indicating the suppression of long-term viscoelastic deformation. The combined results demonstrate that nanoindentation provides a sensitive, nondestructive tool for monitoring the evolution of cross-linking and viscoelastic stability in SU-8 films, offering valuable insight for process optimization and mechanical reliability in MEMS and microfluidic applications. Full article

With the discovery of amorphous oxide semiconductors, a new era of electronics opened. Indium gallium zinc oxide (IGZO) overcame the problems of amorphous and poly-silicon by reaching mobilities of ~10 cm²/Vs and demonstrating thin-film transistors (TFTs) are easy to manufacture on transparent and flexible substrates. However, mobilities over 30 cm²/Vs have been difficult to reach and other materials have been introduced. Recently, polycrystalline In₂O₃ has demonstrated breakthroughs in the field. In₂O₃ TFTs have attracted attention because of their high mobility of over 100 cm²/Vs, which has been achieved multiple times, and because of their use in scaled devices with channel lengths down to 10 nm for high integration in back-end-of-the-line (BEOL) applications and others. The present review focuses first on the material properties with the understanding of the bandgap value, the importance of the position of the charge neutrality level (CNL), the doping effect of various atoms (Zr, Ge, Mo, Ti, Sn, or H) on the carrier concentration, the optical properties, the effective mass, and the mobility. We introduce the effects of the non-parabolicity of the conduction band and how to assess them. We also introduce ways to evaluate the CNL position (usually at ~E_C + 0.4 eV). Then, we describe TFTs’ general properties and parameters, like the field effect mobility, the subthreshold swing, the measurements necessary to assess the TFT stability through positive and negative bias temperature stress, and the negative bias illumination stress (NBIS), to finally introduce In₂O₃ TFTs. Then, we will introduce vacuum and non-vacuum processes like spin-coating and liquid metal printing. We will introduce the various dopants and their applications, from mobility and crystal size improvements with H to NBIS improvements with lanthanides. We will also discuss the importance of device engineering, introducing how to choose the passivation layer, the source and drain, the gate insulator, the substrate, but also the possibility of advanced engineering by introducing the use of dual gate and 2 DEG devices on the mobility improvement. Finally, we will introduce the recent breakthroughs where In₂O₃ TFTs are integrated in neuromorphic applications and 3D integration. Full article

Organic photovoltaics (OPVs) based on non-fullerene acceptors (NFAs) are rapidly advancing as lightweight, flexible, and low-cost solar technologies, with power conversion efficiencies approaching 20%. To ensure that environmental sustainability progresses symmetrically alongside performance improvements, it is essential to quantify the environmental footprint of these emerging technologies, particularly during early development stages when material and process choices remain adaptable. This study presents a cradle-to-gate life cycle assessment (LCA) of PTB7-Th:ZY-4Cl solar cells, aiming to identify asymmetries in environmental impact distribution and guide eco-efficient optimization strategies. Using laboratory-scale fabrication data, global warming potential (GWP), cumulative energy demand (CED), acidification (AP), eutrophication (EP), and fossil fuel depletion (FFD) were evaluated via the TRACI methodology. Results reveal that electricity consumption in thermomechanical operations (ultrasonic cleaning, spin coating, annealing, and stirring) disproportionately dominates most impact categories, while chemical inputs such as PEDOT:PSS, PTB7-Th:ZY-4Cl precursors, and solvents contribute significantly to fossil fuel depletion. Substituting grid electricity with renewable sources (hydro, wind, PV) markedly reduces GWP, and solvent recovery or replacement with greener alternatives offers further gains. Although extrapolation to a 1 m² pilot-scale module reveals impacts higher than established PV technologies, prospective scenarios with realistic efficiencies (10%) and lifetimes (10–20 years) suggest values of ~150–500 g CO₂-eq/kWh—comparable to fullerene OPVs and approaching perovskite and thin-film benchmarks. These findings underscore the value of early-stage LCA in identifying asymmetrical hotspots, informing material and process optimization, and supporting the sustainable scale-up of next-generation OPVs. Full article

It is well established that solar cells convert solar energy into electrical energy, thereby contributing to environmental sustainability by reducing dependence on fossil fuels. In the present study, thin films composed of different materials were employed with the aim of mitigating efficiency losses in polycrystalline solar cells, which operate at a specific output voltage of 0.5 V. To evaluate the performance of these films, solar irradiation tests were conducted in Ciudad Obregón, Sonora, Mexico, during periods that accounted for both seasonal and diurnal variations in solar irradiance. The experiments were carried out during peak solar hours, a time frame that represents the conditions of highest thermal stress and irradiance intensity and is therefore relevant for analyzing heat-related efficiency losses. The thin films investigated included silver nanoparticles, copper sulfide, potassium permanganate, zinc sulfide, and lead sulfide. An improvement of 0.5% in open circuit voltage gain was achieved, corresponding to a temperature difference of 13.5 °C between the hottest and coolest cells. Notably, the cells that exhibited efficiency enhancement were those incorporating silver nanoparticles and potassium permanganate, with varying deposition times in the chemical bath. Among these, the latter demonstrated superior performance (KMnO₄ performed best). So, the objective of this experimental work was to assess the effect of various thin film coatings on the performance of polycrystalline silicon solar cells under natural sunlight. Full article

High-entropy alloy (HEA) thin films have attracted considerable attention owing to their multi-element synergistic effects, high stability, tunable electronic structure, and low-cost potential. In this study, an FeCoNiMoCu HEA thin-film electrode was successfully fabricated via coating and vacuum sintering techniques, using equiatomic Fe, Co, Ni, Mo, and Cu powders as precursors. The crystal structure, surface morphology, elemental composition/distribution, and chemical states of the FeCoNiMoCu HEA thin-film electrode were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS), respectively. The hydrogen evolution reaction (HER) performance of the electrode was evaluated in four different electrolyte systems. Additionally, the influence of electrolyte temperature on HER activity was investigated, with the corresponding activation energy (E_a) calculated for each tested system. Results demonstrate that the FeCoNiMoCu HEA thin-film electrode exhibits outstanding HER performance across multiple electrolyte systems. Compared with conventional HER catalysts, this FeCoNiMoCu thin-film electrode achieves a balance between high catalytic activity and broad electrolyte compatibility, filling the research gap in HEA thin-film catalysts with superior performance in various complex electrolyte environments and providing a new reference for the development of low-cost, high-stability HER catalysts for practical applications. Full article

Tantalum nitride (TaN) coatings are valued for their hardness, chemical inertness, and biocompatibility; however, they lack intrinsic antibacterial properties, which limits their application in biomedical environments. Introducing copper (Cu) into the TaN matrix offers a potential solution by combining TaN’s mechanical and chemical durability with Cu’s well-documented antimicrobial action. This study explores how varying copper incorporation affects the structural, electrical, photocatalytic, and antibacterial characteristics of TaCuN multilayer films synthesized via reactive magnetron sputtering. Three thin TaCuN films were fabricated using a high-power reactive magnetron co-sputtering system, varying the Cu target power to control the composition. Structural and morphological analysis was performed using X-ray diffraction (XRD), scanning/transmission electron microscopy (STEM/TEM), and energy-dispersive X-ray spectroscopy (EDS). Electrical conductivity was studied along and across the film surfaces at temperatures ranging from 20 to 375 K using AC impedance spectroscopy. Optical and photocatalytic properties were assessed using UV–Vis spectroscopy and methylene blue degradation tests. Antibacterial activity against Staphylococcus aureus was analyzed under visible light using CFU reduction tests. XRD and TEM analyses revealed a multilayered four-zone architecture with alternating Ta-, Cu-, and N-rich phases and a dominant cubic δ-TaN pattern. The layers exhibited pronounced conductivity anisotropy, with in-plane conductivity (~10³ Ω⁻¹ cm⁻¹) exceeding cross-plane conductivity by ~10⁷ times, attributed to the formation of a metallic conduction channel in the mid-layer. Optical spectra indicated limited light absorption above 300 nm and negligible photocatalytic activity. Increasing the Cu content substantially enhanced antibacterial efficiency, with the highest-Cu sample achieving 95.6 % bacterial growth reduction. Morphological evaluation indicated that smooth film surfaces (Ra < 0.2 μm) effectively minimized bacterial adhesion. Reactive magnetron sputtering enables the precise engineering of TaCuN multilayers, combining high electrical anisotropy with robust antibacterial functionality. The optimized TaCuN coating offers promising potential in biomedical and protective applications where both conductivity and microbial resistance are required. Full article

Thin films have become indispensable in shaping the landscape of modern and future technologies, offering versatile platforms where properties can be engineered at the atomic to microscale to deliver performance unattainable with bulk materials. Historically evolving from protective coatings and optical layers, the field has advanced into a highly interdisciplinary domain that underpins innovations in microelectronics, energy harvesting, optoelectronics, sensing, and biomedical devices. In this review, a structured approach has been adopted to consolidate the fundamentals of thin film growth and the governing principles of nucleation, surface dynamics, and interface interactions, followed by an in-depth comparison of deposition strategies such as physical vapor deposition, chemical vapor deposition, atomic layer deposition (ALD), and novel solution-based techniques, highlighting their scalability, precision, and application relevance. By critically evaluating experimental studies and technological implementations, this review identifies key findings linking microstructural evolution to device performance, while also addressing the pressing challenges of stability, degradation pathways, and reliability under operational stresses. The synthesis of evidence points to the transformative role of advanced deposition controls, in situ monitoring, and emerging AI-driven optimization in overcoming current bottlenecks. Ultimately, this work concludes that thin film technologies are poised to drive the next generation of sustainable, intelligent, and multifunctional devices, with emerging frontiers such as hybrid heterostructures, quantum materials, and bio-integrated systems charting the future roadmap. Full article

This research study investigated the effect of edible coatings made from apple pectin, incorporating caffeic and protocatechuic acids, on the quality attributes of Golden Delicious apples during 28 days of storage at ambient conditions. The study evaluated the rheological properties of the coating solutions, the release of phenolic acids from the edible films, and various quality characteristics of the apples. These characteristics included weight loss, colour, total soluble solids, total titratable acidity, pH, firmness, respiration rate, ripeness level, and sensory analysis. The results showed that all coating solutions exhibited non-Newtonian, shear-thinning flow behaviour, with the sample containing protocatechuic acid demonstrating a decrease in apparent viscosity. Additionally, both phenolic acids were released rapidly from the film into a 96% ethanol medium. The study found that bioactive edible coatings, both with and without phenolic acids, were significantly effective in reducing weight loss, colour changes, firmness, and ripening of apples during storage. The total soluble solids were higher in control apples (14.95 ± 0.48 °Brix at 28 days) compared to the coated samples (13.52–13.53 °Brix at 28 days), indicating that the control apples were riper and contained a higher amount of sugars. Ethylene production decreased after 4 weeks of storage, from 60.40 ppm for the apples before storage to 23.55–25.70 ppm for the coated samples, and only to 52.75 ppm for the control apples. Overall, this study confirmed that the use of developed bioactive coatings extends the shelf life of apples by preserving their quality and sensory attributes during storage. Full article

This study investigates the corrosion and scaling behaviour of Extreme High-speed Laser Application (EHLA)-fabricated corrosion-resistant alloy (CRA) claddings under simulated geothermal brine conditions. EHLA 316L stainless steel and alloy 625 coatings were produced and tested in simulated brine (chloride–carbonate–silica geothermal brine) at 70 °C for 720 h to evaluate the influence of additive manufacturing (AM) microstructures on corrosion performance. The EHLA coatings exhibited dense, metallurgically bonded microstructures with minimal porosity. Microstructural analysis revealed Nb- and Mo-rich segregation in EHLA 625 and fine columnar dendritic morphology in all coatings. EHLA 625 developed a stable passive film with only a thin deposit of Mg-O-containing compounds, whereas EHLA 316L exhibited localised pitting and significant Si- and Mg-containing scale accumulation, especially in as-built conditions. Surface finishing reduced corrosion activity by minimising roughness and defect-driven localised attack. Critical pitting temperature (CPT) tests confirmed the superior localised corrosion resistance of EHLA 625 relative to EHLA 316L under laboratory conditions. While these results indicate promising corrosion and scaling resistance of EHLA coatings, further process optimisation and post-deposition thermal treatments might be required to achieve coating performance comparable to wrought alloys. The results indicate the potential of EHLA-fabricated coatings for producing corrosion and scaling resistance surfaces. Full article