Impact of Annealing in Various Atmospheres on Characteristics of Tin-Doped Indium Oxide Layers towards Thermoelectric Applications.

The aim of this work was to investigate the possibility of modifying the physical properties of indium tin oxide (ITO) layers by annealing them in different atmospheres and temperatures. Samples were annealed in vacuum, air, oxygen, nitrogen, carbon dioxide and a mixture of nitrogen with hydrogen (NHM) at temperatures from 200 °C to 400 °C. Annealing impact on the crystal structure, optical, electrical, thermal and thermoelectric properties was examined. It has been found from XRD measurements that for samples annealed in air, nitrogen and NHM at 400 °C, the In2O3/In4Sn3O12 share ratio decreased, resulting in a significant increase of the In4Sn3O12 phase. The annealing at the highest temperature in air and nitrogen resulted in larger grains and the mean grain size increase, while vacuum, NHM and carbon dioxide atmospheres caused the decrease in the mean grain size. The post-processing in vacuum and oxidizing atmospheres effected in a drop in optical bandgap and poor electrical properties. The carbon dioxide seems to be an optimal atmosphere to obtain good TE generator parameters-high ZT. The general conclusion is that annealing in different atmospheres allows for controlled changes in the structure and physical properties of ITO layers.

Recent Advances in Metal-Oxide-Based Photoresists for EUV Lithography.

Extreme ultraviolet lithography (EUVL) is a leading technology in semiconductor manufacturing, enabling the creation of high-resolution patterns essential for advanced microelectronics. This review highlights recent progress in inorganic metal-oxide-based photoresists, with a focus on their applications in EUVL. The unique properties of zinc-based, tin-oxygen, and IVB group inorganic photoresists are examined, showcasing their enhanced chemical reactivity and precise patterning capabilities. Key advancements include the development of zinc oxide and tin oxide nanoparticles, which demonstrate significant improvements in photon absorption and solubility under extreme ultraviolet exposure. Additionally, the review delves into the photochemical reactions of tin-oxygen clusters and the influence of various ligands on film density and cross-linking. The findings suggest that these inorganic photoresists not only improve photolithographic performance but also hold potential for broader applications, such as pyroelectric infrared sensors and 3D printing. Future research directions are outlined, including the optimization of process parameters, the exploration of new ligand and metal combinations, and the evaluation of the environmental benefits of inorganic photoresists over traditional organic ones. These advancements are poised to further enhance the resolution and patterning capabilities required for next-generation semiconductor devices.

Understanding Macrophage Interaction with Antimony-Doped Tin Oxide Plasmonic Nanoparticles.

Antimony-doped tin oxide nanoparticles (ATO NPs) have emerged as a promising tool in biomedical applications, namely robust photothermal effects upon near-infrared (NIR) light exposure, enabling controlled thermal dynamics to induce spatial cell death. This study investigated the interplay between ATO NPs and macrophages, understanding cellular uptake and cytokine release. ATO NPs demonstrated biocompatibility with no impact on macrophage viability and cytokine secretion. These findings highlight the potential of ATO NPs for inducing targeted cell death in cancer treatments, leveraging their feasibility, unique NIR properties, and safe interactions with immune cells. ATO NPs offer a transformative platform with significant potential for future biomedical applications by combining photothermal capabilities and biocompatibility.

Investigation of the Structural Changes in Silk Due to Tin Weighting.

In the 19th century, the weighting of silk with metal salts, such as tin, was a common practice to enhance certain properties of silk fabrics and compensate for the weight loss incurred during the degumming process. This technique induces both physical and chemical modifications to the fibres, contributing to their long-term degradation, which requires thorough investigation. This study aims to examine the structural changes in silk fibres caused by the accumulation of metal salts from the tin-weighting process, using mock-up samples prepared through successive loading with weighting agents using a traditional tin-phosphate treatment method. Unweighted and tin-weighted silk samples were compared using scanning electron (SEM) micrographs, which presented the dispersed nanoparticles on the fibres, while through energy-dispersive X-ray spectroscopy (EDS) elemental mapping, the presence and uniform distribution of the weighting agents were confirmed. Fourier-transform infrared spectroscopy (FTIR) analysis revealed structural changes in tin-weighted silk samples compared to untreated ones, including shifts in amide bands, altered water/hydroxyl and skeletal stretching regions, and increased skeletal band intensities suggesting modifications in hydrogen bonding, ß-sheet content, and structural disorder without significantly impacting the overall crystallinity index. X-ray diffraction (XRD) analysis of both pristine and tin-weighted silk samples revealed significant alterations, predominantly in the amorphous regions of the silk upon weighting. These structural changes were further examined using small-angle X-ray scattering (SAXS) and small- and wide-angle X-ray scattering (SWAXS), which provided detailed insights into modifications occurring at the nanometre scale. The analyses suggested disruptions in ß-sheet crystals and intermolecular packing, especially in the amorphous regions, with increasing amounts of tin-weighting. Contact angle analysis (CA) revealed that the tin-phosphate-weighting process significantly impacted silk surface properties, transforming it from moderately hydrophobic to highly hydrophilic. These changes indicate that the incorporation of tin-phosphate nanoparticles on and within silk fibres could restrict the flexibility of polymer chains, impacting the physical properties and potentially the degradation behaviour of silk textiles. By studying these structural changes, we aim to deepen our understanding of how tin-weighting impacts silk fibre structure, contributing valuable insights into the longevity, conservation, and preservation strategies of silk textiles in the context of cultural heritage.

Selective Extraction of Valuable and Critical Metals in Cassiterite Concentrate by Dry Chlorination, Part I: Thermodynamic and Modelling Perspective.

The chlorination of oxides of major concern in cassiterite concentrate with various chlorinating agents is investigated in light of their thermodynamic feasibilities to extract and recover their valuable metal components. Mechanisms responsible for the processes and their Gibbs free energy changes as a function of temperature to selectively separate and/or recover the metal(s) of interest and unwanted ones as their metallic chlorides are identified. Attention is given to gaseous (Cl2 and Cl2 + CO mixture) and solid (CaCl2 and MgCl2) chlorine sources, from which Cl2 + CO shows no reaction selectivity for any of the oxides but a feasible metal chloride formation for all. Chlorine gas (Cl2), on the other hand, could selectively form chlorides with metals of +2 oxidation state in their oxides, leaving those of high oxidation state unreacted. MgCl2, unlike CaCl2, is found capable of producing calcium, ferrous, and stannic chloride from their metallic oxides with enhanced reaction tendencies in the presence of silicon dioxide (SiO2). An overall study of the thermodynamic feasibility of all chlorine sources looked at alongside operational and environmental viabilities suitably suggests MgCl2 for a selective extraction of the valuable metal components in a cassiterite concentrate, in which case, moderate temperatures seem promising.

Effect of Cl2 Radical on Dry Development of Spin-Coated Metal Oxide Resist.

In this study, the effects of Cl2 radicals on dry development of spin-coated metal oxide resist (MOR) and changes in its surface binding states were investigated to verify the mechanism of dry development. Dry development characteristics of tin hydroxide (Tin OH), which is one of the MOR candidates for next generation lithography, were investigated as functions of process time and temperature using a Cl2 radicals source. Non-UV-exposed Tin OH film showed a linear etch rate (1.77 nm/min) from the initial thickness of ∼50 nm, while the UV-exposed film showed slower etch behavior (1.46 nm/min) in addition to the increase of film thickness for up to 3 min during the Cl2 radical dry development. UV-exposed photoresist (PR) contained more oxygen (Sn-O bonding) in the film due to the removal of butyl compounds from the clusters during the UV exposure process. Therefore, due to the lower reaction of chlorine radicals with Sn-O in the UV-exposed Tin OH than the other bindings, the non-UV-exposed PR was preferentially removed compared to the UV-exposed PR. As the temperature decreases, the overall etch rate decreases, but the difference in etch rate between exposed and unexposed Tin OH becomes larger. Finally, at a substrate temperature of -20 °C, the non-UV-exposed Tin OH with a thickness of 50 nm was completely removed, while ∼30 nm thick PR remained for UV-exposed Tin OH. Eventually, a negative tone development was possible with Cl2 radical plasma due to the difference in activation energy between the UV-exposed and non-UV-exposed films. It is believed that dry development using Cl2 radicals will be one of the most important process techniques for next-generation patterning to remove problems such as pattern leaning, line edge roughness, residue, etc., caused by wet development.

Dual-Stage Reduction Strategy of Tin Perovskite Enables High Performance Photovoltaics.

The rapid oxidation of Sn2+ in tin-based perovskite solar cells (TPSCs) restricts their efficiency and stability have been main bottleneck towards further development. This study developed a novel strategy which utilizes thiosulfate ions (S2O32-) in the precursor solution to enable a dual-stage reduction process. In the solution stage, thiosulfate acted as an efficacious reducing agent to reduce Sn4+ to Sn2+, meanwhile, its oxidation products were able to reduce I2 to I- during the film stage. This dual reduction ability effectively inhibited the oxidation of Sn2+ and passivated defects, further promising an excellent stability of the perovskite devices. As a result, thiosulfate-incorporated devices achieved a high efficiency of 14.78% with open-circuit voltage reaching 0.96 V. The stability of the optimized devices achieved a remarkable improvement, maintaining 90% of their initial efficiencies after 628 hours at maximum-power-point (MPP). The findings provid research insights and experimental data support for the sustained dynamic reduction in TPSCs.

Creation of Excitation-Driven Hypervalent Tin(IV) Compounds For Aggregation-Induced Emission and Application to Thermoresponsive Luminescent Films below Freezing Point.

Although many researchers have devoted their much effort to establish the strategy for developing a stimuli-responsive molecule and tuning of their properties according to the preprogrammed design, it is still challenging to create desired molecules from the scratch. We recently demonstrated that the molecules with a large structural difference between the theoretically optimized structures in the ground and excited states have a potential to exhibit stimuli-responsive luminescent properties. We defined these molecules as an excitation-driven molecule and have shown that they are a versatile platform for designing stimuli-responsive luminescent molecules. Herein, based on the concept of excitation-driven molecules, we show that the hypervalent tin-fused azomethine (TAm) compounds possessing aggregation-induced emission (AIE) properties can be obtained by simple chemical modification with a methyl group although conventional TAm derivatives are well known to be highly luminescent compounds in solution. Furthermore, by combining the solid-state luminescence property of AIE and the coordination number shifts of the hypervalent tin atom, the thermoresponsive films operating below the freezing point are fabricated with the polymer. In this study, we apply the concept of excitation-driven molecules to the hypervalent compounds and demonstrate to obtain the novel functional materials.

Enhancing the wear resistance of titanium alloys through the synthesis of layered double hydroxides combined with titanium nitride coatings.

Given the notoriously poor wear performance of Ti6Al4V (TC4) alloys, two types of MgAl layered double hydroxides (LDHs) were synthesized as lubrication additives. Systematic tribological tests were conducted to explore the performance of the TC4 alloy with these MgAl LDHs at varying concentrations in oil. It was found that, with increasing additive concentration, the wear resistance of TC4 significantly improved. Notably, MgAl LDHs with a hexagonal nanosheet structure exhibited superior lubrication performance, reducing the coefficient of friction (COF) by approximately 67.94 % compared to dry friction, and markedly enhancing the anti-wear characteristics of the TC4 alloy. Furthermore, to improve the utility of TC4 alloy in industrial applications, titanium nitride (TiN) coatings with excellent mechanical properties were deposited onto the TC4 substrate using arc ion deposition. A comprehensive analysis of the tribological behavior and wear mechanisms of TiN coating with the two MgAl LDHs additives was also conducted. Results indicated that the combination of TiN hard coatings and MgAl LDHs lubricants achieved high wear resistance for the TC4 substrate. In conclusion, a low-wear synergistic protection system integrating TiN coatings and high-performance MgAl LDHs lubricants was developed, demonstrating effective protection for TC4 alloys. This strategy not only presents a novel approach for reducing wear in TC4 alloys but also provides a reliable method for safeguarding and ensuring the long-term stability of titanium alloys mechanical components under demanding conditions.

Electrochemical allylations in a deep eutectic solvent.

Electrosynthesis is a technique that is attracting increased attention and has many appealing features, particularly its potential greenness. At the same time, electrosynthesis requires a solvent and a supporting electrolyte in order for current to pass through the reaction. These are effectively consumable reagents unless a convenient means of recycling can be developed. As part of our interest in unusual solvents and electrochemistry, we explored the application of simple, inexpensive, and recyclable deep eutectic solvents to the allylation of carbonyls. While several sets of conditions were developed, the goal of avoiding stoichiometric amounts of metal has proven elusive. Still, a deep eutectic solvent can be used to plate out and thus recover the metal used, offering an interesting new option for electrochemical allylations.

Molecularly Engineered Alicyclic Organic Spacers for 2D/3D Hybrid Tin-based Perovskite Solar Cells.

The high defect density and inferior crystallinity remain great hurdles for developing highly efficient and stable Sn-based perovskite solar cells (PSCs). 2D/3D heterostructures show strong potential to overcome these bottlenecks; however, a limited diversity of organic spacers has hindered further improvement. Herein, a novel alicyclic organic spacer, morpholinium iodide (MPI), is reported for developing structurally stabilized 2D/3D perovskite. Introducing a secondary ammonium and ether group to alicyclic spacers in 2D perovskite enhances its rigidity, which leads to increased hydrogen bonding and intermolecular interaction within 2D perovskite. These strengthened interactions facilitate the formation of highly oriented 2D/3D perovskite with low structural disorder, which leads to effective passivation of Sn and I defects. Consequently, the MP-based PSCs achieved a power conversion efficiency (PCE) of 12.04% with superior operational and oxidative stability. This work presents new insight into the design of organic spacers for highly efficient and stable Sn-based PSCs.

Hydrodeoxygenation of Isoeugenol-derived Model Compound over Carbon-supported Pt and Pt-SnS Catalysts for the Production of Sustainable Jet Fuel.

This study focuses on the sustainable production of bio-jet fuel through the catalytic hydrodeoxygenation (HDO) of isoeugenol (IE). Properties of two spraying synthesis methods (in situ and ex situ metal doping) with different platinum (Pt) loading percentages. The catalyst was characterised using various techniques such as XAS, X-ray photoelectron spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FESEM) and thermogravimetric analysis. The HRTEM and FESEM results show the successful preparation of a spherical nanoparticle doped over activated carbon, and Pt was dispersed on the outer shell of the particles. The catalytic HDO of IE showed a high yield and conversion as follows: IE conversion of 100%, liquid-phase mass balance of 95.92%, dihydroeugenol conversion of 99.32%, propylcyclohexane yield of 88.94% and HYD yield of 76.19%. Moreover, the catalyst exhibited high reusability with low metal leaching and high coke resistance for 10 cycles. The catalyst was evaluated in a continuous flow reactor for 100 h at different reaction temperatures, and interestingly, the catalyst showed low deactivation with a high half-time.

Tin-Lead Perovskite Solar Cells with Preferred Crystal Orientation by Buried Interface Approach.

Mixed tin-lead perovskite solar cells (PSCs) have garnered much attention for their ideal bandgap and high environmental research value. However, poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS), widely used as a hole transport layer (HTL) for Sn-Pb PSCs, results in unsatisfactory power conversion efficiency (PCE) and long-term stability of PSCs due to its acidity and moisture absorption. A synergistic strategy by incorporating histidine (HIS) into the PEDOT: PSS HTL is applied to simultaneously regulate the nucleation and crystallization of perovskite (PVK). HIS neutralizes the acidity of PEDOT: PSS and enhances conductivity. Especially, the coordination of the C═N and -COO- functional groups in the HIS molecule with Sn2+ and Pb2+ induces vertical growth of PVK film, resulting in the release of residual surface stress. Additionally, this strategy also optimizes the energy level alignment between the perovskite layer and the HTL, which improves charge extraction and transport. With these cooperative effects, the PCE of Sn-Pb PSCs reaches 21.46% (1 sun, AM1.5), maintaining excellent stability under a nitrogen atmosphere. Hence, the buried interface approach exhibits the potential for achieving high-performance and stable Sn-Pb PSCs.

Microstructural Instability and Its Effects on Thermoelectric Properties of SnSe and Na-Doped SnSe.

Effects of thermal cycling on the microstructure and thermoelectric properties are studied for the undoped and Na-doped SnSe samples using X-ray computed tomography and property measurements. It is observed that thermal cycling causes significant cracks to develop, which decrease both the electrical and lattice thermal conductivities but do not affect the thermopower. The zT values are drastically reduced after the repeated heat treatment. It is important to account for density changes during cycling to obtain accurate values of the thermal conductivity. Even before thermal cycling, the spark-plasma sintered (SPS) samples have a significant number of microcracks. The orientation of cracks within the SPS pellets and their effect on the microstructure are influenced by the presence of a Na-rich impurity. The SnSe and Sn0.995Na0.005Se samples without the impurity develop cracks and exhibit grain growth parallel to the pellet surface, which is also the plane of the 2D SnSe layers. The Sn0.97Na0.03Se sample containing the impurity develops cracks that are orthogonal to the pellet surface. Such an orientation of cracks in Sn0.97Na0.03Se inhibits grain growth. All samples appear mechanically unstable after thermal cycling.

Plasma-Based Modification of Tin Halide Perovskite Interfaces for Photovoltaic Applications.

Tin halide perovskites represent the most suitable alternative to their lead-based counterparts for sustainable photovoltaics. One of the most important drawbacks of this class of materials is the intrinsic tendency of tin (II) to oxidize under certain conditions and as a consequence of aging. Here, we explore plasma processing to gently treat the surface of the tin perovskite films. As shown by chemical, optical, and morphological analyses, this treatment by generating transient active species on the surface of the material impacts its aging, inhibiting the tendency of tin (II) to oxidize. Plasma-treated stored devices show a power conversion efficiency slightly higher and narrower in the distribution than that of the reference devices. The positive impact of this noninvasive technique, which can be easily implemented in large-area manufacturing facilities, increases the potential of lead-free alternative perovskite photovoltaics.

Photolithography-Free, Solution-Processable Perovskite Electrodes for High-Performance Organic Transistors.

Solution-processable electrodes are promising for next-generation electronics due to their simplicity, cost-effectiveness, and potential for large-area fabrication. However, current solution-processable electrodes based on conductive polymers, carbon-based compounds, and metal nanowires face challenges related to stability, patterning, and production scalability. Here we introduce a novel approach using 3D tin halide perovskites (THPs) combined with a photolithography-free solution patterning technique to fabricate solution-processed electrodes. We demonstrate the preparation of highly conductive CsSnI3 films (234.9 S cm-1) and the fabrication of patterned 35 × 35 perovskite electrode arrays on a 4-in. silicon wafer. These electrodes, used as source/drain electrodes in organic transistors, resulted in devices showing high uniformity and stability. This electrode fabrication strategy is also applicable to other 3D THPs like FASnI3 and MASnI3, showcasing versatility for diverse applications. The results highlight the feasibility and advantages of using 3D THPs as solution-processable electrodes, providing a new material system for the advancement of solution-processed electronics.

The renewed tin-weighting treatment as sustainable and durable flame-retardant approach for protein silk fabric.

The facile development of a sustainable and durable flame-retardant approach for protein silk is of interest. Inspired by silk tin-weighting technology, this study developed a novel and sustainable in-situ deposition strategy based on biomass phytic acid to impart durable flame-retardant performance to silk fabrics. The chemical structure of insoluble chelating precipitation, and the surface morphology, thermal stability, combustion behavior, flame-retardant capacity, laundering resistance, and flame-retardant mode of action of the tin-weighting silk samples, were explored. The Sn-, P-, Si-containing insoluble chelating precipitation formed within the fiber interior and combined with silk fibers through electrostatic attraction and metal salt chelation. As a result, the tin-weighting silk displayed excellent self-extinguishing capacity, with the damaged length reduced to 9.2 cm and the LOI increased to 31.6 %; it also achieved self-extinguishing after 30 washing cycles, demonstrating high flame-retardant efficacy and laundering resistance. Moreover, the tin-weighting silk also showed the obvious suppression in smoke and heat generation by 55.6 % and 35.7 %, respectively. The synergistic charring action of phosphate groups, tin metal salts, and silicates was beneficial for enhancing the fire safety of silk. The tin-weighting treatment also displayed a minor impact on mechanical performance of silk fabrics.

Design and optimization of pore structure in three-dimensional micro-nano hierarchical SnOx supercapacitor electrodes for enhanced ion diffusion.

This paper introduced a novel continuous electrochemical synthesis strategy to address the challenges of slow ion/electron transport rates and low electrode reaction efficiency in Sn-based electrode materials. This approach leveraged the induction and confinement of bubble templates to assist atoms deposition, generating micron-sized tin skeletons. Subsequently, these skeletons were transformed into a secondary nanoporous structure through dissolution-deposition etching effects. From liquid-phase ions to metal skeletons to porous oxides, the sequential material transformations realized the innovative design of three-dimensional (3D) hierarchical structures. This strategy ingeniously exploited the diffusion advantages of the electrolyte in the micro-nano hierarchical structure to achieve the diffusion enhancement of ions, thus solving the "dead surface" problem in the energy storage process. This study revealed the thermodynamic and kinetic feasibility of the constructed 3D micro-nano hierarchical structure through electrochemical evaluations and theoretical calculations, and elucidated the constitutive relationship in which the electrochemical performance of the electrode materials was enhanced with decreasing pore size. In addition, design optimization of pore structures and modelling exploration of pore size limit values were conducted based on density functional theory (DFT) simulations. These simulations demonstrated the advantages of hierarchical structures with controllable pore sizes in facilitating electrolyte ion diffusion, predicting an optimal pore size of 55 µm for 3D hierarchical porous SnOx electrodes. The integration of this innovative structural design with simulation insights offered significant implications for enhancing the sluggish electrode reaction kinetics of metal oxide electrode materials, advancing the controllable fabrication of high-performance energy storage devices.

Optimum Design of InGaN Blue Laser Diodes with Indium-Tin-Oxide and Dielectric Cladding Layers.

The efficiency of current GaN-based blue laser diodes (LDs) is limited by the high resistance of a thick p-AlGaN cladding layer. To reduce the operation voltage of InGaN blue LDs, we investigated optimum LD structures with an indium tin oxide (ITO) partial cladding layer using numerical simulations of LD device characteristics such as laser power, forward voltage, and wall-plug efficiency (WPE). The wall-plug efficiency of the optimized structure with the ITO layer was found to increase by more than 20% relative to the WPE of conventional LD structures. In the optimum design, the thickness of the p-AlGaN layer decreased from 700 to 150 nm, resulting in a significantly reduced operation voltage and, hence, increased WPE. In addition, we have proposed a new type of GaN-based blue LD structure with a dielectric partial cladding layer to further reduce the optical absorption of a lasing mode. The p-cladding layer of the proposed structure consisted of SiO2, ITO, and p-AlGaN layers. In the optimized structure, the total thickness of the ITO and p-AlGaN layers was less than 100 nm, leading to significantly improved slope efficiency and operation voltage. The WPE of the optimized structure was increased relatively by 25% compared to the WPE of conventional GaN-based LD structures with a p-AlGaN cladding layer. The investigated LD structures employing the ITO and SiO2 cladding layers are expected to significantly enhance the WPE of high-power GaN-based blue LDs.

A Graded Redox Interfacial Modifier for High-Performance Perovskite Solar Cells.

Perovskite solar cells have emerged as a potential competitor to the silicon photovoltaic technology. The most representative perovskite cells employ SnO2 and spiro-OMeTAD as the charge-transport materials. Despite their high efficiencies, perovskite cells with such a configuration show unsatisfactory lifespan, normally attributed to the instability of perovskites and spiro-OMeTAD. Limited attention was paid to the influence of SnO2, an inorganic material, on device stability. Here we show that improving SnO2 with a redox interfacial modifier, cobalt hexammine sulfamate, simultaneously enhances the power-conversion efficiency (PCE) and stability of the perovskite solar cells. Redox reactions between the bivalent cobalt complexes and oxygen lead to the formation of a graded distribution of trivalent and bivalent cobalt complexes across the surface and bulk regions of the SnO2. The trivalent cobalt complex at the top surface of SnO2 raises the concentration of (SO3NH2)- which passivates uncoordinated Pb2+ and relieves tensile stress, facilitating the formation of perovskite with improved crystallinity. Our approach enables perovskite cells with PCEs of up to 24.91%. The devices retained 93.8% of their initial PCEs after 1000 hours of continuous operation under maximum power point tracking. These findings showcase the potential of cobalt complexes as redox interfacial modifiers for high-performance perovskite photovoltaics.