Search Results (485)

Copper–aluminum (Cu-Al) wire-bonded devices are widely used in microelectronic packaging; however, corrosion at exposed Cu-Al bimetallic interfaces can lead to Al pad degradation, undercutting, and eventual ball-bond lift-off or open-circuit failure under humid, halide-contaminated conditions. This work presents a scalable post-wire-bond wet-chemical passivation process using octadecylphosphonic acid (ODPA) to simultaneously modify exposed Cu/Pd-coated Cu (PCC) and Al surfaces. The passivation process includes a hydroxylation pretreatment to generate reactive oxide/hydroxide surface sites, followed by ODPA treatment and solvent rinsing to remove weakly adsorbed species. Surface modification was evaluated using contact-angle measurements, reflection–absorption infrared spectroscopy (RAIRS), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). ODPA treatment increased the water contact angle on Cu and Al, confirming a substantial increase in surface hydrophobicity following coating formation. RAIRS identified ODPA-associated aliphatic C-H bands, AFM showed treatment-induced nanoscale surface changes, and XPS supported metal–oxygen–phosphorus interfacial bonding. Under aggressive 100 ppm chloride-ion immersion, ODPA passivation strongly suppressed corrosion-induced ball-bond lift-off across both device platforms. Lift-off decreased from 99.0% to 0.73% for Cu-Al devices and from 23.3% to 0.42% for PCC-Al devices. Collectively, these findings establish an effective, process-compatible post-wire-bond strategy for substantially protecting corrosion-susceptible interfaces and thereby improving the reliability of wire-bonded interconnects in halide-containing environments. Full article

Developing lead-free organic-inorganic hybrid metal halides with strong light-harvesting capabilities and superior stability, while precisely tuning their crystalline phases and electronic structures, remains a key challenge in optoelectronics. Herein, we report a neutral iodine-induced structural transition from a 1D chain-like (C₆H₁₁NH₃)₂SbI₅ architecture to a 0D dimeric (C₆H₁₁NH₃)₃[Sb₂I₉]·I₂ supramolecular host-guest complex. This transformation is achieved via a controlled solution-cooling crystallization process, yielding high-quality bulk single crystals. Crystallographic analysis reveals that N–H···I hydrogen-bonding networks stabilize the organic cations, while halogen bonding interactions anchor the I₂ guests within the lattice cavities of the [Sb₂I₉]³⁻ dimeric host. Experimental characterizations, including XRD, TGA, and XPS, confirm the high phase purity and thermal stability of the (C₆H₁₁NH₃)₃[Sb₂I₉]·I₂ hybrid and determine its electronic band structure. To further elucidate the underlying mechanisms, theoretical calculations were performed, revealing that strong sp-orbital hybridization yields a high absorption coefficient. The associated dimensional transition narrows the direct optical bandgap to 1.46 eV, approaching the Shockley-Queisser limit and demonstrating strong potential for visible-light harvesting. This work elucidates the role of supramolecular host-guest interactions in modulating the lattice evolution of lead-free antimony-based materials, presenting halogen guest engineering as an effective approach for optoelectronic material design. Full article

The luminescence efficiency of Mn²⁺-doped metal halides is often limited by concentration quenching caused by Mn-Mn interactions. In this work, the alkaline-earth cadmium chloride BaCd₂Cl₆·6H₂O:Mn²⁺ was synthesized via a mechanical grinding method. The three-dimensional network framework of this compound effectively isolates Mn²⁺ ions with a Mn-Mn separation of 4.87 Å, thereby suppressing concentration quenching. Under 254 nm ultraviolet excitation, the sample exhibits efficient orange emission centered at 588 nm with a photoluminescence quantum yield (PLQY) as high as 98%. Temperature-dependent photoluminescence studies reveal that the optimal emission temperature of this system is 320 K, demonstrating good thermal stability. This work achieves, for the first time, near-unity Mn²⁺ luminescence efficiency in a Ba-site alkaline-earth cadmium halide system, demonstrating that alkaline-earth-site confinement provides an effective strategy for achieving highly efficient Mn-doped halide luminescence. Full article

Ammonia provides a versatile platform for the synthesis and chemical modification of layered nitride materials. Among these, layered nitride halides of the MNX family have attracted considerable attention because of their superconductivity upon electron doping and their rich structural chemistry. Many of these compounds, including both α- and β-type phases, are synthesised via ammonia-mediated reactions, highlighting the central role of NH₃ chemistry in this class of materials. In this review, we summarise ammonia-mediated synthesis routes and reaction environments for layered nitride halides and related nitride materials, with particular emphasis on bulk synthesis strategies. As a case study, we discuss the synthesis and electron-doped superconductivity of TiNI, a less explored member of the MNX family. We further highlight recent developments in ammonia-driven reactions that enable the formation and modification of nitride phases, including nitrogen-rich ZrN derived from layered precursors while retaining their morphological features. These examples demonstrate that ammonia-mediated processes provide a unified platform for controlling structure, composition, and electronic states across a wide range of reaction conditions. Full article

The rational design of metal-free catalysts capable of efficiently converting CO₂ under atmospheric pressure remains a significant challenge in sustainable chemistry. Herein, we report a series of clamp-shaped dihydrogen-bonded iodide catalysts (CDBI catalysts) featuring a preorganized bifunctional framework that integrates dual hydrogen-bond donors and an intrinsic iodide nucleophile within a single molecular scaffold. Systematic structural variation revealed that catalytic activity is highly sensitive to electronic modulation, steric accessibility, and precise spatial arrangement between the hydrogen-bonding units and the iodide center. The optimal catalyst enabled solvent-free cycloaddition of CO₂ with epoxides at 1 atm CO₂, affording up to 99% conversion and >99% selectivity at 80 °C within 12 h. Substrate scope studies demonstrated efficient transformation of a wide range of terminal epoxides, while sterically demanding substrates exhibited reduced reactivity consistent with a confined activation mode. Mechanistic investigations support a cooperative pathway in which dual hydrogen-bond activation and proximal halide nucleophilicity operate synergistically within a preorganized clamp-shaped pocket. Comparative analysis with representative catalytic systems highlights the ability of this metal-free design to achieve high efficiency under atmospheric CO₂ without cocatalysts or solvents. These findings demonstrate that structural preorganization represents an effective strategy for promoting sustainable CO₂ utilization under operationally simple conditions. Full article

Halide solid electrolytes (HSE) have shown remarkable stability against high-voltage cathodes. Some HSE, such as Li₃InCl₆ (LIC), can be readily synthesized via aqueous routes. Here, we expand the aqueous synthesis of LIC to include Y substitution, which has different hydration coordination strengths, to form Li₃In_xY_1−xCl₆ (LIYC, 0 ≤ x ≤1). This composition is intended to combine the high ionic conductivity of LIC with the superior stability of Li₃YCl₆ (LYC). We compared solution-synthesized products with those derived mechanochemically. We found that adding ammonium chloride in a 3:1 ratio to YCl₃ + InCl₃ produces a phase-pure product, with X-ray diffraction (XRD) revealing structure similarity for both routes. Through nuclear magnetic resonance (NMR) and impedance measurements, we evaluate how the synthesis method affects ionic transport, particularly regarding correlated motion. Despite lower initial grain boundary impedance in mechanochemical samples, full cells made from solution-synthesized samples show superior cycling performance. This work establishes a scalable aqueous synthesis route for LIYC that achieves properties comparable to traditional mechanochemical methods. Full article

All-solid-state lithium–sulfur batteries (ASSLSBs) couple the high theoretical energy density of sulfur (2600 Wh kg⁻¹) with the safety and polysulfide-shuttle suppression advantages of solid electrolytes (SEs). In practice, however, sluggish solid-state conversion kinetics, chemo-mechanical degradation in composite cathodes, and large solid–solid interfacial resistance remain the principal barriers to practical implementation. This review systematically examines recent progress across the three key components of ASSLSBs: cathodes, solid electrolytes, and interfaces. For cathodes, S/C composite design strategies and alternative active materials—including Li₂S, metal sulfides, and organosulfur compounds—are discussed. For solid electrolytes, inorganic (sulfide, oxide, halide, and hydride), polymer, and hybrid composite systems are compared. For interfaces, physical strategies (stack pressure, compliant interlayers, three-dimensional cathode architectures) and chemical strategies (cathode–SE and Li metal–SE interphase engineering, in situ stabilization) are evaluated. Outstanding challenges and design guidelines for next-generation ASSLSBs are discussed. Full article

Organic–inorganic hybrid metal halides (OIMHs), especially zero-dimensional (0D) ones, have been recognized as an excellent class of luminescent materials due to their structural diversity and tunable emission properties. In this work, using the environmentally friendly Zn(II) ion as the central metal and 1,4,7,10-tetraazacyclododecane (Cyclen) as the organic component, we successfully synthesized a novel OIMH, (H₃Cyclen)(ZnBr₄)·Br·H₂O. Single-crystal X-ray diffraction analysis reveals that (H₃Cyclen)(ZnBr₄)·Br·H₂O possesses a 0D structure, in which the [ZnBr₄]²⁻ tetrahedra are uniformly separated by the organic amine cations. This structural feature is expected to enhance the material’s stability and optimize its optoelectronic properties. Under UV lamp irradiation, (H₃Cyclen)(ZnBr₄)·Br·H₂O emits bright blue-green light. Therefore, we systematically investigated its luminescence properties. The emission mechanism was further elucidated using UV–vis absorption spectroscopy and DFT calculations. Finally, (H₃Cyclen)(ZnBr₄)·Br·H₂O was employed as a luminescent material to fabricate a white light-emitting diode (WLED), demonstrating its potential as an excellent phosphor material. Full article

The efficiency of perovskite solar cells has increased to a certified value of 27% over the past decade, benefiting from the superior properties of metal halide perovskite materials. However, their long-term operational stability is still far inferior to that of commercial crystalline silicon solar cells. A key source of this instability is field-driven ion migration in vertical architectures, along with the consequent degradation at the absorber–electrode interfaces. Compared with the widely investigated vertical structures, back-contacted (BC) perovskite solar cells—wherein both electrodes are positioned on the same side of the absorber—offer a unique route to suppress interfacial ion migration and thereby enhance long-term device stability. These advantages are especially pronounced when combined with single-crystal perovskites, which possess low charge trap densities, long carrier diffusion lengths, and high bulk ion migration barriers. Unfortunately, only a handful of research groups have participated in the development of single-crystal BC perovskite solar cells; thus, the advancement of this area lags far behind that of its vertical counterpart. Therefore, a review that discusses the recent developments and challenges of single-crystal BC perovskite solar cells is urgently required to provide guidelines for this emerging field. In this progress report, we first introduce the main growth methods of single-crystal wafers compatible with BC architectures, followed by an outline of the developmental history of BC perovskite solar cells. Finally, the core bottlenecks facing single-crystal BC devices and corresponding optimization strategies are discussed in detail. Full article

Thin-film solar cells (TFSCs) remain a cornerstone of the global transition toward renewable energy, characterized by consistent reductions in manufacturing costs and steady gains in power conversion efficiency. In addition to electricity generation, TFSCs play an important role in advanced solar thermal cooling, heating, and energy storage systems, where their tunable optical absorption, low thermal mass, and flexibility enable integration with photovoltaic–thermal (PV/T) collectors, thermally driven cooling cycles, and hybrid thermal–electrical storage architectures. This paper provides a comprehensive review of prominent TFSC technologies, including copper indium gallium selenide (CIGS), cadmium telluride (CdTe/CdS), amorphous silicon (a-Si), copper zinc tin sulfide (CZTS), organic photovoltaics (OPVs), and metal halide perovskite solar cells (PSCs), with a focus on their material structures, performance specifications, and current efficiency benchmarks. Compared to state-of-the-art reviews, this article distinguishes itself by addressing next-generation innovations, cross-domain solar thermal–photovoltaic applications, and economic analysis. Specifically, the integration of machine learning and simulation-based material dynamics is examined to accelerate material discovery, process optimization, and the characterization of novel TFPV components relevant to coupled thermal–electrical energy systems. Furthermore, the study explores how additive manufacturing is transforming the industry through the development of high-efficiency electrodes, electrohydrodynamic atomization for thin-film deposition, and the fabrication of flexible solar arrays suitable for thermally integrated and building-scale energy systems, including space applications. By integrating advancements in module efficiency, scalable manufacturing approaches, and techno-economic analysis, this paper positions TFSCs as sustainable, resource-abundant technologies essential for next-generation solar thermal cooling, heating, and energy storage infrastructures. Full article

Halide-based solid electrolytes have emerged as promising candidates for next-generation all-solid-state lithium metal batteries due to their high room-temperature ionic conductivity, wide electrochemical stability window, and favorable mechanical properties. This review provides a comprehensive overview of the fundamental structure–property relationships, Li⁺ transport mechanisms, and performance optimization strategies for Li₃MX₆-type halide solid electrolytes. The unique structural framework of halide electrolytes, characterized by close-packed anion sublattices (hexagonal close-packed and cubic close-packed) and edge-sharing [MX₆]³⁻ octahedral networks, establishes three-dimensional Li⁺ percolation pathways with low migration barriers (0.20–0.33 eV). This review concludes by identifying key challenges and future research directions, including high-entropy halide design, scalable aqueous synthesis methods, earth-abundant material alternatives, and integrated cell architectures that combine halide catholytes with complementary anolyte materials for practical all-solid-state battery applications. Full article

Soil moisture monitoring is critical to agricultural production and water resource management, yet existing sensors often exhibit limitations in accuracy, cost-effectiveness, and long-term stability. This study aimed to develop a high-performance capacitive soil moisture sensor to address these issues. We selected eco-friendly lead-free K₂CuBr₃ as the hygroscopic material and optimized the interdigital electrode (IE) structure via theoretical analysis and finite element simulation. The sensors were fabricated using micro-electro-mechanical system (MEMS) technology, and their performance was systematically evaluated with real soil samples. The results demonstrated that K₂CuBr₃ substantially enhanced the sensor sensitivity. The optimal sensor exhibited a measurement error of approximately 5% over the soil moisture range of 0–42.5%, a relative standard deviation (RSD) of less than 2%, and good stability. This low-cost, lead-free MEMS capacitive sensor, based on K₂CuBr₃, offers high accuracy and excellent stability. It resolves key drawbacks of traditional sensors and offers a reliable solution for in situ real-time soil moisture monitoring, with broad prospects in smart agriculture. Full article

Background/Objectives: Electrolytes used in in vitro corrosion testing critically determine the behavior inferred for metallic dental implants, yet formulations and their justifications are inconsistently reported across the literature. This review compiles and compares electrolytes employed to simulate the oral cavity and the bone–implant interface, linking their chemical composition to the corrosion mechanisms they target. Methods: This structured narrative review synthesized peer-reviewed literature on simulated electrolytes used for in vitro corrosion testing of metallic dental implants and implant-related alloys. Literature was identified using database searches and targeted reference screening, with emphasis on artificial saliva formulations, physiological simulated fluids, challenge chemistries, protein-containing media, hydrodynamic conditions, and microbiological models. Relevant formulations were standardized to grams per liter and grouped according to application domain and targeted corrosion mechanisms. Results: The analysis maps electrolyte selection to corresponding corrosion modes, including uniform dissolution, pitting, crevice, galvanic, and microbiologically influenced corrosion. Consolidated composition tables highlight how pH, halide concentration, calcium–phosphate balance, proteins, gas control, and flow conditions modify passive-film stability and metal-ion release. Dental-specific gaps are identified, notably the lack of a standardized fluoride–pH matrix and limited guidance for microbiome-integrated assays. Conclusions: Aligning electrolyte formulations with the research question enhances reproducibility and mechanistic interpretation. However, current in vitro corrosion data should be interpreted cautiously because quantitative links between simulated-fluid testing and clinical outcomes such as peri-implantitis, peri-implant bone loss, and implant failure remain insufficiently established. The adoption of shared reporting standards, dynamic programmable chemistries, and interoperable datasets may improve the translational value of future corrosion studies. Full article

The increasing demand for better dental aesthetics has driven the development of tooth-whitening techniques that are effective while reducing invasiveness. Hydrogen peroxide (HP) and carbamide peroxide (CP) continue to be the most common active ingredients in bleaching products. Various types of light and laser activation have been introduced to speed up the bleaching process and decrease clinical application time. However, published results regarding their effectiveness and biological safety are inconsistent and sometimes contradictory. Aim: The objective of this study was to identify irradiation conditions that optimise the whitening performance of peroxide-based bleaching agents while ensuring safety for dental hard tissues and ocular structures. This objective was achieved through a systematic synthesis and meta-analyses of both experimental and clinical evidence on bleaching techniques, light or laser activation, and related treatment outcomes. Additionally, the study aimed to provide an integrated overview of currently used irradiation technologies, bleaching agents, treatment protocols, and relevant safety considerations. Methods: A multi-stage analytical approach was employed. Evidence was collected from systematic reviews, randomised and non-randomised clinical trials, and laboratory-based in vitro investigations. The studies assessed differences in bleaching agents (HP and CP), their concentrations, and application protocols, as well as various activation systems, including halogen lamps, conventional LEDs, violet LEDs, metal–halide lamps, and laser wavelengths such as visible blue (~440 nm), red or near-infrared (~1.7 µm), and other spectral ranges. Extracted outcome measures included tooth colour improvement (ΔSGU, ΔE), incidence of tooth sensitivity, changes in enamel surface morphology, temperature increases in the pulp chamber, and the bond strength of restorative or orthodontic materials. When methodological compatibility permitted, quantitative synthesis and meta-analysis were conducted to estimate the effects of activation modalities and irradiation parameters. Results: Analysis of data from 28 systematic reviews and numerous clinical and laboratory studies showed that the degree of colour improvement did not consistently rely on peroxide concentration or on whether bleaching was performed in-office or through home-based protocols. In most studies, adding light activation did not produce a clearly superior whitening effect compared to chemically driven bleaching alone. However, certain laser-assisted methods—especially those using blue diode lasers around 440 nm or near-infrared diode lasers near 1.7 µm—were linked with faster whitening responses and, in several in vitro experiments, fewer enamel surface irregularities. Increases in pulp temperature remained below the generally accepted safety threshold of 5.5 °C in the reported experimental conditions. While laser activation reduced treatment time, some studies observed a temporary decrease in the bond strength of orthodontic brackets following bleaching. Photobiomodulation techniques seem promising for reducing post-treatment sensitivity, although more robust clinical evidence is still needed. Conclusions: Targeted activation with diode lasers, especially within the blue and near-infrared spectral ranges, may speed up the whitening process and potentially minimise structural changes to enamel when irradiation parameters are carefully managed. Despite these positive findings, current clinical evidence remains limited. Well-designed randomised controlled trials with standardised treatment protocols are essential to determine the best wavelengths, energy delivery settings, and safety limits for laser-assisted dental bleaching. Full article

Metanil Yellow (MY), a highly toxic azo dye used in food products, was removed from aqueous solution using a metal- and halide-free ordered mesoporous carbon (OMC) adsorbent. MY exhibited a strong affinity towards OMC in batch as well as column operations, and OMC performed much better than previously reported adsorbents. The pH, dye concentration, adsorbent dosage, and contact time were optimised, and detailed adsorption experiments were performed under these conditions. Several isotherm models were fitted to the adsorption data, showing that the Langmuir and the Freundlich adsorption models were followed. Adsorption was spontaneous and endothermic at all measurement temperatures. On the basis of pH studies, enthalpy data, and adsorption isotherm analysis, adsorption was determined to be by physisorption. In kinetics studies, the adsorption process was found to be pseudo-second order with interparticle diffusion as the rate-limiting step. Column experiments using a fixed bed of OMC resulted in almost 100% column efficiency and a fractional column capacity of 0.999. During adsorption/desorption cycles of the exhausted column, 99.71% of the dye was recovered after the first cycle and 97.66% after the eleventh. These findings indicate that OMC is a promising and efficient material for the adsorptive removal of toxic MY dye. Full article