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Based on the extended Bogoliubov–de Gennes theory, the inhomogeneous stripe order and Majorana bound states are demonstrated in s -wave superconducting systems with Rashba spin–orbit interaction when the in-plane Zeeman field is applied. For a fully open square sample, topological phase transitions can be driven by the Zeeman field, and the stripe phase with spatially oscillating order parameter shows up across a critical field strength. The topological channels arise in this phase, which can be utilized to create and manipulate Majorana zero modes. Interestingly, (quasi-)one-dimensional channels with diminished pairing amplitude can be formed in narrow arms of a square loop, accompanied by the reconstruction of energy spectra of the condensate and the realization of robust Majorana zero-energy states at the ends of channels. The associated evolution of topological phases and the location of Majorana zero modes are highly sensitive to the field direction. Moreover, the effects of the rectangular aspect-ratio and the off-centered hole as well as the surface defects on Majorana end modes are explored in Rashba asymmetric loops. In comparison, the field-dependent evolution processes of low-energy levels behave more complicated because the emergence of confined topological channels can be effectively tuned by the length and width of loop arms as well as the size and position of an introduced small indentation at the outer edge. Rich patterns of Majorana corner-like states are generated for such asymmetric systems. Our theoretical predictions may shed new light on the tunability of Majorana zero modes and provide useful guidance for future experiments and applications. [ABSTRACT FROM AUTHOR]

InGaN micro-LEDs (μ LEDs) with their potential high-volume applications have attracted substantial research interest in the past years. In comparison to other III–V semiconductors, InGaN exhibits a reduced susceptibility toward non-radiative surface recombination. However, efficiency degradation becomes more prominent as dimensions shrink to a few μ m or less. Due to the high surface-to-volume ratio of the miniaturized devices, the non-radiative recombination increases and reduces the internal quantum efficiency. While many groups focus on surface passivation to mitigate surface defects, the influence of crystallographic orientation of the μ LED sidewall on the efficiency remains unexplored. This study addresses this gap by investigating the impact of crystallographic orientation of the sidewalls on the emission properties of the μ LEDs. Hexagonal and elongated μ LEDs with dimensions as small as 3.5 μ m and sidewalls with crystallographically well-defined m- and a-planes were fabricated. Electrical and optical properties were investigated using photo- and electroluminescence. External quantum efficiency (EQE) is assessed based on well-known carrier recombination models. It can be shown that μ LED performance intrinsically depends on the crystallographic orientation of the sidewalls. Comparing hexagonal μ LED structures with a-plane and m-plane sidewalls, an increase in the EQE by 33 % was observed for structures with a-plane sidewalls, accompanied by reduction in the current density of the peak EQE by a nearly two orders of magnitude compared to structures with m-plane sidewalls. By analyzing the EQE characteristics at the μ LED center and near the sidewalls, the improvements can be directly attributed to the increased radiative recombination from sidewalls with a-plane orientation. [ABSTRACT FROM AUTHOR]

Chiral quantum dots (QDs) are promising materials applied in many areas, such as chiral molecular recognition and spin selective filter for charge transport, and can be prepared by facile ligand exchange approaches. However, ligand exchange leads to an increase in surface defects and reduces the efficiencies of radiative recombination and charge transport, which restricts further applications. Here, we investigate the light-induced photoluminescence (PL) enhancement in chiral L- and D-cysteine CdSe QD thin films, providing a strategy to increase the PL. The PL intensity of chiral CdSe QD films can be significantly enhanced over 100 times by continuous UV laser irradiation, indicating a strong passivation of surface defects upon laser irradiation. From the comparative measurements of the PL intensity evolutions in vacuum, dry oxygen, air, and humid nitrogen atmospheres, we conclude that the mechanism of PL enhancement is photo-induced surface passivation with the assistance of water molecules. [ABSTRACT FROM AUTHOR]

This paper describes a three-step process to remediate surface and sub-surface defects on chemo-mechanically polished SiC surfaces. In this process, a CF4-based inductively coupled plasma with reactive ion etch was used to remove material to a depth, which is unaffected by surface and subsurface polishing damage. This produced a planarized but carbon-rich fluorinated surface. This surface was then exposed to a 2 min rapid thermal oxidation in air at 1000 °C to oxidize and volatilize the excess carbon and fluorinated species, respectively. The resulting surface oxide was then stripped using a dilute hydrofluoric acid in water solution. This process, referred to as plasma assisted remediation, reproducibly yielded planarized, stoichiometric surfaces with low levels of carbon and oxygen contamination suitable for subsequent device fabrication. In the supporting studies described here, 4H- and 6H-SiC(0001) surfaces were remediated and characterized by x-ray photoelectron spectroscopy and atomic force microscopy at each stage of the process. Experimental studies under ion-rich and radical-dominant conditions are also reported which provide greater insight into the underlying chemistry and physics of the process. [ABSTRACT FROM AUTHOR]

In many modern applications, it is important to understand mechanisms of non-equilibrium chemistry and physics that are driven by low energy ion bombardment of solid surfaces. However, the study of these processes has been challenging as it demands a relatively unique balance between chemical fidelity and computational cost. To this end, we have proposed and constructed a new, high-throughput simulation pipeline based on density functional tight binding simulations. Additionally, we have extended the parameter set pbc-0-3 with the addition of Ar, thereby enabling the simulation of Ar bombardment. This pipeline was then applied to study the structural and compositional evolution of silicon nitride (SiN) under Ar bombardment. We identified a possible rate limiting step of bombardment-driven sputtering of SiN and suggested underlying mechanisms of Si and N removal. Damage from the bombardment, including generation of surface defects and Ar implantation, are further discussed. These findings and the newly developed simulation framework will serve as a useful foundation for further research in processes driven by ion bombardment. [ABSTRACT FROM AUTHOR]

MoS2 has generated significant attention due to its unique electronic properties and versatile applications. Being a van der Waals material, MoS2 is expected to exhibit an inert surface due to lack of dangling bond. However, our photoemission study finds MoS2 to be highly sensitive toward residual gases. The position of the valence band maximum (VBM) shifts even in a vacuum of 10−10 Torr. We find this to be due to CO adsorption causing unintentional electron doping. The time evolution of the position of VBM is exponential, and it reaches two different saturation points, depending on whether the sample is exposed to ultraviolet (UV) radiation or not. Our XPS (x-ray photoemission spectroscopy) study shows no time-dependent escape of sulfur, which was in a previous study attributed to a VBM shift. The VBM shift can be reversed by annealing, sputtering, and UV light, which desorb CO gases. The study shows that the MoS2 surface is easily doped, which offers the possibility of using it as a sensor but in many other applications could diminish device performance and needs to be considered. [ABSTRACT FROM AUTHOR]

MoS2 has generated significant attention due to its unique electronic properties and versatile applications. Being a van der Waals material, MoS2 is expected to exhibit an inert surface due to lack of dangling bond. However, our photoemission study finds MoS2 to be highly sensitive toward residual gases. The position of the valence band maximum (VBM) shifts even in a vacuum of 10−10 Torr. We find this to be due to CO adsorption causing unintentional electron doping. The time evolution of the position of VBM is exponential, and it reaches two different saturation points, depending on whether the sample is exposed to ultraviolet (UV) radiation or not. Our XPS (x-ray photoemission spectroscopy) study shows no time-dependent escape of sulfur, which was in a previous study attributed to a VBM shift. The VBM shift can be reversed by annealing, sputtering, and UV light, which desorb CO gases. The study shows that the MoS2 surface is easily doped, which offers the possibility of using it as a sensor but in many other applications could diminish device performance and needs to be considered. [ABSTRACT FROM AUTHOR]

SiCp/Al composites are widely used in the aerospace field due to their excellent properties. However, the huge difference in the properties of silicon carbide and aluminum matrix materials can easily lead to machining defects. Ultrasonic vibration-assisted machining is an effective method to deal with difficult-to-machine materials. In this study, ultrasonic elliptical vibration is applied to the helical milling of SiCp/Al composites. Firstly, the ultrasonic elliptical vibration-assisted helical milling (UEVHM) cutting-edge trajectory is modeled, and the equation of the UEVHM tool-chip separation condition is established, which lays a foundation for the analysis of the cutting mechanism. Then, the influence of ultrasonic elliptical vibration on the removal mechanism of SiCp/Al composites was investigated by finite element simulation. It was found that UEVHM can reduce the tearing of aluminum matrix and reduce the hole damage by changing the direction of the cutting velocity and the relative position of the cutting edge and particles. Finally, the single-factor experiment was carried out, and the surface morphology and roughness of HM and UEVHM were compared. The influence of process parameters on the surface roughness of UEVHM was analyzed. The experimental results show that compared with HM, UEVHM can reduce surface defects and exit damage, to obtain better surface roughness and exit edge quality. The increase in cutting speed can reduce the roughness, and the increase in pitch and revolution speed will increase the surface roughness. [ABSTRACT FROM AUTHOR]

Defects are inherent in transition metal dichalcogenides and significantly affect their chemical and physical properties. In this study, surface defect electrochemical nanopatterning is proposed as a promising method to tune in a controlled manner the electronic and functional properties of defective MoS₂ thin films. Using parallel electrochemical nanolithography, MoS₂ thin films are patterned, creating sulphur vacancy‐rich active zones alternated with defect‐free regions over a centimetre scale area, with sub‐micrometre spatial resolution. The patterned films display tailored optical and electronic properties due to the formation of sulphur vacancy‐rich areas. Moreover, the effectiveness of defect nanopatterning in tuning functional properties is demonstrated by studying the electrocatalytic activity for the hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

The article reports the synthesis of an ordered mesoporous network of heterophase TiO2 monoliths as a visible light-responsive photocatalyst using tri-block copolymers of Pluronic F108, P123 and F127 as structure-directing agents (SDAs) and temperature-controlled calcination (450–650 °C) has been carried out by direct templating-assisted hydrothermal approach. The structural/surface morphology and topographical properties of the photocatalyst are characterized using FE-SEM-EDAX, HR-TEM-SAED, p-XRD, VB-XPS, PLS, TG/DTA, UV-Vis-DRS, BET/BJH and zeta potential analysis. The undoped heterophase mesoporous TiO2 monoliths with in-built lattice/surface defects exhibit visible light photocatalytic properties, successfully dissipating Reactive Brown 10 (RB-10) dye. The influence of physicochemical parameters, such as SDAs, temperature, pH, dye concentration, catalyst dosage, photosensitizers and light intensities, are optimized for maximum photocatalytic performance at a shorter timespan. The F127-assisted mesoporous TiO2 monolith (550 °C) exhibits superior degradation kinetics (15 min) for RB-10 dye solution (20 ppm) at pH 2.0–3.0 using a photocatalyst dosage of 50 mg and 2 mM of KBrO3, irradiated with 150 W/cm2 tungsten lamp. The photocatalysts are fabricated without complicated chemical modifications and display topmost efficiency in quickly decontaminating persistent pollutants. The photoproducts from RB-10 photocatalytic degradation are investigated using HR-MS analysis. The photocatalyst can be reused efficiently for six cycles, even under extreme conditions. [ABSTRACT FROM AUTHOR]

Our previous research papers have shown the potential of deep-learning models for real-time detection and control of porosity defects in 3D printing, specifically in the laser powder bed fusion (LPBF) process. Extending these models to identify other defects like surface deformation poses a challenge due to the scarcity of available data. This study introduces the use of Transfer Learning (TL) to train models on limited data for high accuracy in detecting surface deformations, marking the first attempt to apply a model trained on one defect type to another. Our approach demonstrates the power of transfer learning in adapting a model known for porosity detection in LPBF to identify surface deformations with high accuracy (94%), matching the performance of the best existing models but with significantly less complexity. This results in faster training and evaluation, ideal for real-time systems with limited computing capabilities. We further employed Gradient-weighted Class Activation Mapping (Grad-CAM) to visualize the model's decision-making, highlighting the areas influencing defect detection. This step is vital for developing a trustworthy model, showcasing the effectiveness of our approach in broadening the model's applicability while ensuring reliability and efficiency. [ABSTRACT FROM AUTHOR]

A novel design and approach for the realization of liquid crystal optical waveguides using photopatterning as a manufacturing method is presented. The developed method is used to demonstrate straight waveguides of different widths and curved waveguides with different radius of curvature. The waveguides are terminated with +1 or −1 surface defects through which the light incouples/outcouples. The effect of the straight waveguide thickness and the radius of curvature of the curved waveguides on the attenuation of the light in the waveguide is experimentally explored. The experiments are supported with numerical simulations of light propagation through both types of waveguides and outcoupling out of the straight waveguides. Furthermore, the effect of the size of the −1 defect terminations on the outcoupling efficiency is explored using simulations. Based on the presented design and manufacturing approach, liquid crystal optical waveguides of various shapes can be realized accurately with low‐cost. [ABSTRACT FROM AUTHOR]

Water splitting is an energy conversion process of vital importance. The oxygen evolution reaction (OER), as the half-reaction of water splitting, has very slow kinetics due to the complex quaternary electron transfer process involved, which greatly impedes the efficiency of energy conversion. The rational construction and modification of metal–organic frameworks (MOFs) offer a novel alternative for developing efficient OER electrocatalysts. In this study, MOF-74-PA15 with abundant surface defects and high hydrophilicity was successfully in situ constructed by etching MOFs for different reaction times using phytic acid (PA). The etching of PA increases the active area, and improves the hydrophilicity, allowing tighter contact between the material and the electrolyte. As a result, MOF-74-PA15 exhibits the most optimal OER catalytic performance in all the samples. The overpotential is 250 mV in 1 M KOH at 100 mA cm−2, with the lowest Tafel slope (35.59 mV dec−1). Furthermore, MOF-74-PA15 exhibits excellent stability. It maintains stability for 72 hours at a current density of 50 mA cm−2. This study presents a novel and feasible solution for modifying MOFs as electrocatalytic water splitting catalysts. [ABSTRACT FROM AUTHOR]

While operational stability has evolved to be the primary issue for the practical applications of perovskite solar cells (PSCs), the understanding of the origins of device degradation is still limited. Hysteresis is known as a unique and significant feature of PSCs. The hysteresis behavior of the current density-voltage (J–V) curves, governed by the interaction between the evolving ion-induced electric field and the carrier transport/recombination, offers rich and important information about the physical properties of the device. Herein, we propose to establish hysteresis as a diagnostic key to unveil and remedy degradation issues with device physics. With a custom-made ion-incorporated drift-diffusion simulator, we comprehensively investigate the relations between characteristic J–V hysteresis features and critical device issues such as bulk and surface defects, and low mobility of each layer in the PSCs. Ultimately, we derive a fundamental understanding and unveil the origins of the device degradation during the continuous operation of PSCs. This work therefore offers a new way to address and optimize PSC operational stability. The understanding of the origins of device degradation of perovskite solar cells remains limited. Here, the authors establish hysteresis as a diagnostic key to unveil and remedy degradation issues and investigate the relations between characteristic J-V hysteresis features and device deficiencies. [ABSTRACT FROM AUTHOR]

Perovskite solar cells have become a leading contender in next‐generation photovoltaic technologies due to their high efficiency and low‐cost potential. Managing the deep defects present effectively in the crystal lattice and at the interfaces is essential for enhancing the performance and longevity of perovskite solar cells. Here, perovskite's crystallization modulation and interfacial defect passivation are achieved by developing a guanidinium iodide (GAI)‐based surface passivation strategy. The integration of GAI passivates the grain boundaries, leading to a perovskite thin film with a smoother and more uniform grain distribution, facilitating charge carrier transport. Notably, the ammonium group, unsaturated nitrogen atoms, and iodide ions in GAI can collectively repair the surface defects of perovskite through various pathways, effectively suppressing non‐radiative recombination, thereby enhancing the photovoltaic performance of the device. Ultimately, the champion device treated with GAI achieves a power conversion efficiency (PCE) of 23.02% and demonstrates similar ambient stability under unencapsulated conditions. These findings underscore the effectiveness of GAI passivation as a strategy to balance the improvement of the performance and stability of perovskite solar cells. [ABSTRACT FROM AUTHOR]

The surface defect has a direct impact on the performance and quality of the final product, so it is crucial to identify the key factors causing the defect. To achieve accurate key factor identification, an eXplainable AI‐based Pipeline (XAIP) is proposed herein. The proposed XAIP combines data mode clustering and local model construction to meet practical application requirements. Meanwhile, after analyzing the characteristics of practical data, a strategy for defect rate calculation is designed to provide more fine‐grained defect‐related information to supervise model training. The final identification results are presented by a two‐stage explainable method, which is designed to reveal the information of data modes and key variables and can give engineers more specific defect‐related information. The experiment results based on two practical manufacturing datasets show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Due to the polycrystalline cubic boron nitride tool has the characteristics of high hardness, brittleness, etc., it is easy to break the tool or produce defects in the laser cutting process, which affects the cutting performance of the tool. Traditional defect detection methods can no longer meet the needs of modern manufacturing. Aiming at the problems of low accuracy and poor real-time detection of surface defects on laser-cutting polycrystalline cubic boron nitride tools, this study proposes the surface defect detection model of laser cutting polycrystalline cubic boron nitride tool based on asymptotic fusion strategy, which fills the gap in the field. In the backbone network, the C3SE module is constructed by modeling the correlation between feature channels to improve the model's focus on key features in order to enhance the feature extraction and processing capability of the backbone network; In the neck network, adaptive spatial fusion operation and direct interaction of non-adjacent layers are utilized for multi-scale information fusion, and the asymptotic feature pyramid network for object detection (AFPN) is used instead of the FPN structure to improve the detection performance; In the head network, a soft suppression mechanism is introduced to reduce the overlapping frame score using a decay function, thus improving the detection accuracy. The experimental results based on the self-constructed laser-cutting polycrystalline cubic boron nitride tool surface defects dataset show that the average accuracy of the AFFS-YOLO model is improved by 5.6% compared with that of the YOLOv5 model, reaching 86.1%, and the detection effect is better than that of the original network and other classical target detection networks. [ABSTRACT FROM AUTHOR]

Crystalline red phosphorus (CRP), known for its promising photocatalytic properties, faces challenges in photocatalytic hydrogen evolution (PHE) due to undesired inherent charge deep trapping and recombination effects induced by defects. This study overcomes these limitations through an innovative strategy in integrating ruthenium single atoms (Ru1) within CRP to simultaneously repair the intrinsic undesired vacancy defects and serve as the uniformly distributed anchoring sites for a controllable growth into ruthenium nanoparticles (RuNP). Hence, a highly functionalized CRP with Ru1 and RuNP (Ru1‐NP/CRP) with concerted effects in regulating electronic structures and promoting interfacial charge transfer has been achieved. Advanced characterizations unveil the pioneering dual role of pre‐anchored Ru1 (analogous to the "Tai Chi" principle) in transforming CRP photocatalysis. The regulations of vacancy defects on the surface of CRP minimize the detrimental deep charge trapping, resulting in the prolonged lifetime of active charges. With the well‐distributed in situ growth of RuNP on Ru1 sites, the constructed robust "bridge" that connects CRP and RuNP facilitates constructive interfacial charge transfer. Ultimately, the synergistic effect induced by the pre‐anchored Ru1 endows Ru1‐NP/CRP with an exceptional PHE rate of 3175 μmol h−1 g−1, positioning it as one of the most efficient elemental‐based photocatalysts available. This breakthrough underscores the crucial role of pre‐anchoring metal single atoms at defect sites of catalysts in enhancing sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) suffer from a quick efficiency drop after fabrication, partly due to surface defects, and efficiency can be further enhanced with the passivation of surface defects. Herein, surface passivation is reviewed as a method to improve both the stability and efficiency of PSCs, with an emphasis on the chemical mechanism of surface passivation. Various molecules are utilized as surface passivants, such as halides, Lewis acids and bases, amines (some result in low-dimensional perovskite), and polymers. Multifunctional molecules are a promising group of passivants, as they are capable of passivating multiple defects with various functional groups. This review categorizes these passivants, in addition to considering the potential and limitations of each type of passivant. Additionally, surface passivants for Sn-based PSCs are discussed since this group of PSCs has poor photovoltaic performance compared to their lead-based counterpart due to their severe surface defects. Lastly, future perspectives on the usage of surface passivation as a method to improve the photovoltaic performance of PSCs are addressed to provide a direction for upcoming research and practical applications. [ABSTRACT FROM AUTHOR]

Surface treatment of perovskite materials with their layered counterparts has become an ubiquitous strategy for maximizing device performance. While layered materials confer great benefits to the longevity and long‐term efficiency of the resulting device stack via passivation of defects and surface traps, numerous reports have previously demonstrated that these materials evolve under exposure to light and humidity, suggesting that they are not fully stable. Therefore, it is crucial to study the behavior of these materials in isolation and in conditions mimicking a device stack. Here, it is shown that perovskite capping layers templated by a range of cations on top of methylammonium lead iodide devolve in conditions commonly found during perovskite fabrication, such as exposure to light, solvent, and moisture. Photophysical, structural, and morphological studies are used to show that the degradation of these layered perovskites occurs via a self‐limiting, pinhole‐mediated mechanism. This results in the loss of whole perovskite sheets, from a few monolayers to tens of nanometers of material, until the system stabilizes again as demonstrated for exfoliated flakes of PEA2PbI4. This means that initially targeted structures may have devolved, with clear optimization implications for device fabrication. [ABSTRACT FROM AUTHOR]

Lead halide perovskite exhibits great prospects in next‐generation display. However, single‐cation inorganic perovskite nanocrystals (NCs) still suffer from offset gamut coordinates determined by bandgap, short operating life, and low‐efficiency in light‐emitting diodes (LEDs), on account of the limitations in lattice stability and defect levels. Here, a thermodynamic co‐competition strategy is proposed for fabricating Cs1−xFAxPbBr3 NCs, which reveals the spatial distribution of A‐site cations and the improvement of photoelectronic performance. This strategy achieves precise control of NCs in the pure‐green range with an accuracy of sub‐nanometer, further promotes the comprehensively filling‐suppressing effect of incongruous lattice and surface defects. Finally, the high‐precision adjusting in electroluminescence is achieved, and the champion device achieves a CIE coordinate of (0.121, 0.788), meeting the pure‐green range in BT.2020. Simultaneously, the PeLED demonstrates an EQE exceeding 20% with superior stability, accompanied by 20‐fold improvement in lifetime, indicating tremendous potential in next‐generation display. [ABSTRACT FROM AUTHOR]

The formation mechanism of pore defects and surface ripples takes a crucial position in quality control during the laser powder bed fusion process. This paper explores the evolution of the melt pool in the LPBF process and elucidates the impact of flow state and temperature field distribution on the melt pool with different process parameters. Through computational fluid dynamics methodology, the study clarifies the formation mechanism of pore defects and surface ripples. The discrete element method was applied to simulate the powder bed using a set of processing parameters. The free surface of the melt pool was then calculated employing the volume of fluid method. It was found that surface ripples on the melt pool and irregular pore defects in the lap joints appeared due to the lack of fusion at a laser energy density of 32 J/mm3 under the pre-set conditions. As the laser scanning speed dropped to 600 mm/s, keyholes were generated inside the melt pool due to the recoil pressure. Similar phenomena of pore defects and surface ripples were observed in the experiments. The measured and simulated average widths of the molten track showed good agreement, with relative errors of less than 6%, confirming the accuracy of the simulated formation. Our work sheds new light on the quality control of LPBF fabricated parts for the future. [ABSTRACT FROM AUTHOR]

The notch effect significantly influences the fatigue response of components and is particularly relevant for parts produced with additive manufacturing (AM) processes, characterized by complex geometries and possible geometric discontinuities inducing local and critical peak stresses. Moreover, the low surface quality, as well as manufacturing defects and residual stresses, interacts with the local peak stress induced by geometric discontinuities, complicating the assessment of the notch effect for AM parts and requiring extensive experimental fatigue investigations. In the present paper, the notch sensitivity of as‐built AlSi10Mg specimens produced with the laser beam powder bed fusion in the Very High Cycle Fatigue regime is investigated. Ultrasonic fatigue tests up to 109 cycles have been carried out on rectangular bars and rectangular bars with a central through‐thickness hole. The notch effect has been found to significantly affect the fatigue response of the investigated AlSi10Mg specimens, with surface defects having a main role and pointing out the influence of the surface quality on the crack formation. Highlights: Notch sensitivity on the very high cycle fatigue (VHCF) response of AlSi10Mg specimens is investigated.The AlSi10Mg VHCF fatigue response is strongly influenced by the notch.The experimental fatigue notch factor is close to that computed with literature models.Experimental tests are recommended to account for the large experimental scatter. [ABSTRACT FROM AUTHOR]

Packaging plastics are being substituted by more sustainable materials to satisfy modern‐life requirements. For example, utilisation of biocoated paperboards for packaging is one of the options; however, certain challenges exist in maintaining the integrity of the coated surface. In this study, the barrier formation and convertibility properties of a novel suberin dispersion coating were examined and compared with those of six commercial coatings by measuring their oil and grease resistance and using scanning electron microscopy (SEM) before and after creasing. Even before creasing, SEM revealed deep cavities on the coated surfaces, with the potential to impair the material barrier properties. Furthermore, finite element modelling provided evidence that creasing stresses emerged under the rules and in nearby areas. These outer stresses with internal fibre structure realignment caused the formation of surface defects such as grazes, microcracks and coating ruptures. The deepest defects, which critically reduce the barrier properties, were oriented parallel to the machine direction of the materials. In contrast, the cross‐machine direction‐oriented defects were bridged by the substrate fibres and did not penetrate that deeply into the coating thickness. The amount and severity of the surface damage revealed by SEM were correlated with the actual oil resistance measured for each material. The results indicate that the suberin dispersion exhibits promising barrier performance as a paperboard coating but requires further development to enhance its resistance to the conversion stresses. [ABSTRACT FROM AUTHOR]

KFeSO4F (KFSF) is considered a potential cathode due to the large capacity and low cost. However, the inferior electronic conductivity leads to poor electrochemical performance. Defect engineering can facilitate the electron/ion transfer by tuning electronic structure, thus providing favorable electrochemical performance. Herein, through the regulation of surface defect engineering in reduced graphene oxide (rGO), the Fe-C bonds were formed between KFSF and rGO. The Fe-C bonds formed work in regulating the Fe-3d orbital as well as promoting the migration ability of K ions and increasing the electronic conductivity of KFSF. Thus, the KFSF@rGO delivers a high capacity of 119.6 mAh g-1. When matched with a graphite@pitch-derived S-doped carbon anode, the full cell delivers an energy density of 250.5 Wh kg-1 and a capacity retention of 81.5% after 400 cycles. This work offers a simple and valid method to develop high-performance cathodes by tuning defect sites. [ABSTRACT FROM AUTHOR]

Polymeric hole‐selective materials (P‐HSMs) offer advantages like solution processability, tunable energy levels, and improved mechanical stability, making them suitable for large‐scale and flexible substrates. Poly[bis(4‐phenyl) (2,4,6‐trimethylphenyl) amine] (PTAA) based p–i–n perovskite solar cells exhibit promising power conversion efficiency (PCE), but wettability, dopant, and cost challenges necessitate the development of advanced next‐generation P‐HSMs. To provide a clear understanding of the structural property with photovoltaic performance, this review classifies such newly developed P‐HSMs into five distinct structural categories. Specifically, this review discusses the current status, advancements, challenges, and prospects in structural design and synthetic variations, focusing on enhancing photovoltaic performance, wettability, mitigating surface defects, and stability. Notably, incorporating polar units into P‐HSMs enhances wettability and mitigates ion instabilities and uncoordinated lead defects. Promising structural designs like polymeric self‐assembled monolayers and in situ polymerized hole‐selective materials are examined. Despite performance advancements, emerging, P‐HSMs face significant challenges such as limited thermal stress analysis (55–85 °C) and scalability restricted to small‐scale devices. To bridge this gap, this review emphasizes the urgent need for prioritizing thermal stability testing and large‐scale device fabrication in future research, paving the way for commercial viability of P‐HSMs in p–i–n perovskite photovoltaics. [ABSTRACT FROM AUTHOR]

In the production of strip steel, surface defect identification is crucial for improving product quality and ensuring smooth subsequent processes. Existing technologies face challenges such as low detection efficiency and susceptibility to environmental noise. This article employs an automated deep learning method without requiring consideration of complex environmental changes and proposes an improved RepVGG (ViT‐RepVGG) model for surface defect identification. The model is based on the RepVGG architecture, and the study explores the impact of incorporating the self‐attention mechanism of ViT under various addition strategies on model performance. A comparison is made between the optimized model and classic network models, as well as recently published models, in terms of identification performance. The research also examines the performance variations of the model under different hyperparameter settings and its identification performance for six types of defects. The results indicate that adding the ViT module to stage 3 of the A1‐type RepVGG, with a learning rate, optimizer, and activation function set to 0.0001, Adam, and Gelu, respectively, yields the optimal ViT‐RepVGG model performance. These findings demonstrate the feasibility of enhancing classification performance by incorporating the self‐attention mechanism into neural networks, providing an effective foundation for the online identification of strip steel surface defects. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries are pivotal in modern energy storage, commonly utilizing graphite anodes for their high theoretical capacity and long cycle life. However, graphite anodes face inherent limitations, such as restricted lithium-ion storage capacity and slow diffusion rates. Enhancing the porosity of graphite and increasing d-spacing in expanded graphite anodes have been explored to improve lithium-ion diffusion and intercalation. Recent advancements suggest that nanoscale modifications, such as utilizing nano-graphite and graphene, can further enhance performance. Laser processing has emerged as a promising technique for synthesizing and modifying graphite and graphene-related materials, offering control over surface defects and microstructure. Here, we demonstrate an industrially compatible one-step laser processing method to transform a nano-graphite and graphene mixture into a nanoporous matrix, significantly improving lithium-ion battery performance. The laser-processed anodes demonstrated significantly enhanced specific capacities at all charge rates, with improved relative performance at higher charge rates. Additionally, long-term cycling at 1 C showed that laser-processed cells outperformed their non-processed counterparts, with specific capacities of 323 and 241 mAh/g, respectively. [ABSTRACT FROM AUTHOR]

The passivating-step-free strategy is essential to fabricating high-quality large-area perovskite film with less defects, which can be implemented in semi-transparent perovskite solar modules. The functional additive not only modulates perovskite crystalline orientation but also passivates perovskite surface defects without post-treatment passivation step, contributing to a notable efficiency of 18.71% for semi-transparent FA 0.95 Cs 0.05 PbI 3 solar module with an aperture area of 64.0 cm2. [Display omitted] [ABSTRACT FROM AUTHOR]

Understanding the interfacial composition in heterostructures is crucial for tailoring heterogenous electrochemical and photoelectrochemical processes. This work aims to elucidate the structure of a series of Co−Fe Prussian blue analogue modified ZnO (PBA/ZnO) electrodes with interface‐sensitive vibrational sum frequency generation (VSFG) spectroscopy. Our measurements revealed, for the first time, a cyanide linkage isomerism at the PBA/ZnO interface, when the composite is fabricated at elevated temperatures. In situ VSFG spectro‐electrochemistry measurements correlate the CoII→CoIII oxidation with the flip of the bridging CN ligand from Co−NC−Fe coordination mode to a Co−CN−Fe one. Photoluminescence measurements and X‐ray photoelectron spectroscopy reveal that this unprecedented linkage isomerism originates from surface defects, which act as oxidation sites for the PBA. The presence of such surface defects is correlated with the fabrication temperature for PBA/ZnO. Thus, this contribution identifies the interplay between the surface states of the ZnO substrates and the chemical composition of PBA at the ZnO surface, suggesting an easily accessible approach to control the chemical composition of the interface. [ABSTRACT FROM AUTHOR]

Though 3D printing shows potential in fabricating complex optical components rapidly, its poor surface quality and dimensional accuracy render it unqualified for industrial optics applications. The layer steps in the building direction and the pixelated steps on each layer's contour result in inevitable microscale defects on the 3D‐printed surface, far away from the nanoscale roughness required for optics. This paper reports a customized vat photopolymerization‐based lens printing process, integrating unfocused image projection and precision spin coating to solve lateral and vertical stair‐stepping defects. A precision aspherical lens with less than 1 nm surface roughness and 1 µm profile accuracy is demonstrated. The 3D‐printed convex lens achieves a maximum MTF resolution of 347.7 lp mm−1. A mathematical model is established to predict and control the spin coating process on 3D‐printed surfaces precisely. Leveraging this low‐cost yet highly robust and repeatable 3D printing process, the precision fabrication of multi‐scale spherical, aspherical, and axicon lenses are showcased with sizes ranging from 3 to 70 mm using high clear photocuring resins. Additionally, molds are also printed to form multi‐scale PDMS‐based lenses. [ABSTRACT FROM AUTHOR]

Structural engineering, coupled with crystalline phase engineering and surface engineering, serves as a practical and effective strategy for enhancing catalytic performance through the fine design of catalysts in terms of their structure, physical phases and surface defects. In this work, a set of strategies were employed for structural transformation and crystalline phase transition of Ru/TiO2 catalysts, utilizing multidimensional regulation. Ru nanoparticles loaded on a unique TiO2 nanosheet flowers (Ru/TSFs) enriched with pores and Ti3+ defects were prepared by solvothermal and impregnation‐chemical reduction methods. The Ru/TSFs exhibited an outstanding catalytic performance in the reaction of selective hydrogenation of benzene for the preparation of cyclohexene, with a selectivity of 79 % and a maximum yield of 52.8 % along with a benzene conversion of 45.9 % and a good stability. The excellent catalytic performance attributes to the distinctive structure of three‐dimensional nanosheet flowers, which offers a high specific surface area and improvs the effective contact between the catalyst and the reaction substrate. Meanwhile, the porous Ru/TSFs exhibit exceptional hydrophilicity and abundant Ti3+ defects on their surface, which is quite favorable for the desorption of cyclohexene from the reaction system, thus improving the selectivity of cyclohexene. The multidimensional engineering may provide an efficient approach for constructing high‐performance loaded catalysts for potential industrial applications. [ABSTRACT FROM AUTHOR]

All‐inorganic CsPbCl3 perovskite has emerged as a promising material for ultraviolet (UV) photodetection, attributed to its appropriate bandgap and exceptional optoelectronic properties. However, the suboptimal film‐forming quality of the solution process, as well as the instability of films induced by UV radiation and the annealing process, have limited its popularization and application. Herein, the buried layer is pretreated with N, N‐dimethylacetamide (DMF) to improve surface hydrophilicity and facilitate the anchoring of Pb2+. Additionally, Nb2CTx is incorporated into the PbCl2 precursor solution to enhance the quality of CsPbCl3 films. Following surface engineering and Nb2CTx modification (CsPbCl3@Nb2CTx), the morphology and optoelectronic properties of CsPbCl3 films are optimized. Furthermore, the effect of lattice strain and defect state‐induced interface state on the nonradiative charge recombination is mitigated. Ultimately, the UV photodetector fabricated on fluorine‐doped tin oxide (FTO)/SnO2/CsPbCl3@Nb2CTx/Au architecture exhibits outstanding performance including remarkably high responsivity (up to 990 mA W−1), significant specific detectivity (1.03 × 1011 cm Hz1/2 W−1), and rapid rise/decay time (0.24/0.32 µs) under self‐powered mode, with markedly improved stability as well. This approach presents a novel strategy for optimizing CsPbCl3 films through MXene modulation as an immense potential absorb layer for UV photodetector. [ABSTRACT FROM AUTHOR]

Surface cracks pose a hidden danger to metal pipes application. Several technical issues exist in crack detection in metal pipes, such as overexposure, low accuracy, and low detection speeds. To address the aforementioned key technical issues, this study proposes an image acquisition system with multiple lighting fusion and a metal-pipe crack defect segmentation model. These methods achieve the objective of acquisition and recognition of surface cracks in metal pipes by combining annular and coaxial light and introducing dual attention and boundary refinement modules. We contribute a surface defects on metal pipes dataset. Empirical evidence demonstrates that, within our proposed dataset, the methodology presented in this paper surpasses 20 state-of-the-art methods in terms of detection accuracy, while achieving a detection speed of 161.9 fps. Furthermore, in comparisons on public datasets, this study's method outperformed 12 state-of-the-art approaches in achieving superior detection accuracy. The code for the metal-pipe crack defect segmentation model is located in https://github.com/zz-ux/Semantic-Segmentation-Network-for-Surface-Cracks-in-Metal-Pipes. [ABSTRACT FROM AUTHOR]

Current additive manufacturing (AM) techniques for tungsten, such as powder bed fusion and directed energy deposition, often generate parts with rough surfaces. Vat photopolymerization presents a promising alternative for fabricating tungsten structures with high shape fidelity and low surface roughness. However, existing vat photopolymerization approaches suffer from surface defects and low final density, leading to compromised mechanical properties. Therefore, achieving high‐density tungsten structures using vat photopolymerization remains a crucial challenge. This work presents a straightforward and reliable method for fabricating complex, micro‐architected tungsten structures with superior density and hardness. The approach utilizes a water‐based photoresin with exceptional tungsten ion loading capacity. The photoresin is then patterned using digital light processing (DLP) to create tungsten‐laden precursors. A three‐step debinding and sintering process subsequently achieves 3D tungsten structures with dense surface morphology and minimal internal defects. The microstructures achieve a minimum feature size of 35 µm, a low surface roughness of 2.86 µm, and demonstrate exceptional mechanical properties. This new method for structuring tungsten opens doors to a broad range of applications, including micromachining, collimators, detectors, and metamaterials. [ABSTRACT FROM AUTHOR]

Bilayer 3D/2D heterojunction perovskite solar cells (PSCs) have attracted increasing interest due to great advantages of high power conversion efficiency (PCE) and ultrastability. Previous studies are mostly focused on addressing the issue of poor charge transport originated from the spacer cations or random phase distribution of 2D perovskite in 3D/2D heterojunction. However, the carrier recombination at the surface of 2D layer is often ignored. Herein, a novel strategy of passivating 2D perovskite in 3D/2D heterojunction with a thin surface termination layer (STL) is proposed. It demonstrates that surface defects of 2D perovskite are terminated by the molecule of 2‐amino‐5‐mercapto‐1,3,4‐thiadiazole through multi‐site interaction, leading to the significant suppression of non‐radiative recombination and considerable improvement of hole transport with the well‐aligned energy band simultaneously. As a result, the PSCs with the constructed 3D/2D/STL structure processed in air have achieved a champion PCE of 25.09% with high open‐circuit voltage of 1.211 V (the voltage deficient of 0.349 V). The unencapsulated devices retain exceeding 90% of the initial PCE after storing in air for 1008 h or under illumination in N2 for 504 h. This work opens up an important, but unnoticed topic of defect passivation of 2D perovskite for 3D/2D heterojunction PSCs. [ABSTRACT FROM AUTHOR]

The twin-roll casting (TRC) of light metal alloys, in particular aluminium and magnesium alloys, represents a promising technology for the production of lightweight components thanks to its short process chain and promising combinations of properties. In the production of strip products, TRC is susceptible to a number of defects due to the coupled process steps of casting and forming, which prevent its use for more complex alloy combinations in the field. In this review, the defects in TRC of light metal alloys will be summarized and discussed. In addition to a basic classification of the defect types and definition of these, the formation mechanisms and avoidance strategies will be discussed. Special focus is placed on centreline segregation defects and surface bleeds, which occur in a large number of investigations in the literature. Effective avoidance strategies are defect-specific, but are mostly due to the combination of the plant design of the TRC process, the TRC parameters or the use of alloying elements to influence the solidification process. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries can offer high capacity and energy‐density, but face challenges like low conductivity, lithium polysulfides (LiPSs) shuttling, and limited reaction kinetics. In this study, the electronic configuration of Mo 4d orbital in MoS2 is modulated through a one‐step method involving tungstate anion (WO42−) modulation to form a stable 1T‐MoS2/carbon composite (1T‐W‐MoS2/C). When WO42− is introduced, it causes a transfer of electrons to Mo in 2H‐MoS2, resulting in the generation of a stable 1T phase. In the composite, 1T‐MoS2 nanosheets exhibit remarkable electronic conductivity, hydrophilicity, and catalytic activity, facilitating the LiPSs adsorption and Li+ transport. Meanwhile, the WO42− modulation can create abundant adsorption/catalytic sites with defects on the basal surface and edges of MoS2, facilitating the efficient catalysis of LiPSs conversion. Furthermore, the 3D‐printed electrodes without utilization of binders and current collectors can ensure high mass loading and promote ion diffusion and electrolyte penetration. Theoretical and experimental results confirm that 1T‐W‐MoS2/C can catalyze LiPSs conversion, suppress LiPSs shuttling, and enhance sulfur reaction kinetics. Therefore, the 3D‐printed 1T‐W‐MoS2/C/S cathode exhibits a high initial capacity and excellent rate capability, achieving an areal capacity of 7.37 mAh cm−2 with a sulfur loading of 8.89 mg cm−2. [ABSTRACT FROM AUTHOR]

Improving wind power generation efficiency and lowering maintenance and operational costs are possible through the early and efficient diagnosis and repair of surface defects in wind turbines. To solve the lightweight deployment difficulty and insufficient accuracy issues of the traditional detection methods, this paper proposes a high-precision PC-EMA block based on YOLOv8 using partial convolution (PConv) combined with an efficient multiscale attention (EMA) channel attention mechanism, which replaces the bottleneck layer of the YOLOv8 backbone network to improve the extraction of target feature information from each layer of the network. In the feature fusion phase, GSConv, which can retain more channel information, is introduced to balance the model's complexity and accuracy. Finally, by merging two branches and designing the PConv head with a low-latency PConv rather than a regular convolution, we are able to effectively reduce the complexity of the model while maintaining accuracy in the detection head. We use the WIoUv3 as the regression loss for the improved model, which improves the average accuracy by 5.07% and compresses the model size by 32.5% compared to the original YOLOv8 model. Deployed on Jetson Nano, the FPS increased by 11 frames/s after a TensorRT acceleration. [ABSTRACT FROM AUTHOR]

In order to study the effect of laser-excited surface waves on the transmission of surface rectangular defects, the transmission information of surface waves is used to achieve the quantitative calculation of defect depth. In this paper, the finite element method is employed to analyse the transmission process of laser-excited surface waves on rectangular defects. Subsequently, the influence of the front and back edges of rectangular defects on the transmission of surface waves is examined, and the formation mechanisms of feature points in the time-domain signals at detection points are elucidated. Ultimately, the calculation formula for defect depth is derived on the basis of the propagation path of each component after transmission. The experimental results are consistent with the simulation results, and the relative error of the surface rectangular defect depth calculation is within 9%. The validation of the proposed method on homogeneous isotropic metallic materials demonstrates the effectiveness and applicability of the proposed method. These results will provide a reliable method for characterising the depth of rectangular defects on surfaces by laser ultrasonic technology. [ABSTRACT FROM AUTHOR]

Highlights This research involved the modification of carbon fiber (CF) through electrochemical anodizing under different conditions and focused on analyzing the impact of modifying CF surface and examining the interfacial characteristics of thermoset polyimide (PI) composites. The process of electrochemically oxidizing CF consists of two distinct stages. The oxidation stage mainly occurs under the conditions of low current intensity and low electrolyte concentration, at the graphite boundary defects on CF surface. The etching effect stage intensifies on CF surface under high current intensity and electrolyte concentration, resulting in the fracture and detachment of the carbon rings. Electrochemical oxidation improves CF roughness and the quantity of active functional groups, which enhances mechanical interlocking and chemical bonding between CF and PI. Furthermore, the introduction of reactive hydrogen groups can contribute to the PI curing process, significantly improving the weak interface bonding problem between CF and PI. The interfacial shear strength (IFSS) of the composites increased from 82.08 to 104.33 MPa and 114.08 MPa in acidic and alkaline electrolyte environments, respectively. Improved interfacial compatibility between CF and polyimide resin through electrochemical oxidation The relationship between the physical morphology and chemical composition of the surface of CF and their interfacial properties was investigated. The interfacial shear strength of CF/PI was increased by 38.99% without any loss in mechanical properties of the CF. The electrochemical oxidation mechanism of CF under different electrolytes was revealed. [ABSTRACT FROM AUTHOR]

(1) Background: Air rudders are used to control the flight attitude of aircraft, and their surface quality directly affects flight accuracy and safety. (2) Method: Traditional positioning methods can only obtain defect location information at the image level but cannot determine the defect's physical surface position on the air rudder, which lacks guidance for subsequent defect repair. We propose a defect physical surface positioning method based on a camera mapping model. (3) Results: Repeated positioning experiments were conducted on three typical surface defects of the air rudder, with a maximum absolute error of 0.53 mm and a maximum uncertainty of 0.26 mm. Through hardware systems and software development, the real-time positioning function for surface defects on the air rudder was realized, with the maximum axial positioning error for real-time defect positioning being 0.38 mm. (4) Conclusions: The proposed defect positioning method meets the required accuracy, providing a basis for surface defect repair in the air rudder manufacturing process. It also offers a new approach for surface defect positioning in similar products, with engineering application value. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to evaluate the effect of etching protocols on bond strength, surface roughness, and mechanical properties of a zirconia-reinforced lithium silicate (ZLS) CAD/CAM-ceramic. In total, 100 bars (ISO 6872), 75 plaques, and 25 cubes were cut from ZLS blocks(Vita Suprinity®). The surfaces were standardized, crystallized and divided into five groups: 1. control (no/treatment-C), 2. 5%-Hydrofluoric-acid (HF)/20 s (HF5%20s), 3.HF5%60s, 4.HF10%20s, and 5.HF10%60s. Flexural strength (FS) (three-point bending test, 1 mm/min), roughness (Pa), and micro-shear bond-strength (µSBS) tests were performed. The data were statistically analyzed with one-way ANOVA, Tukey's test (p ˂ 0.05) and Weibull (FS data). C showed higher Pa (1.176 ± 0.370 µm) than HF10%60s (0.627 ± 0.236 µm) and all other groups. Groups C and 20 s showed the most irregular surface patterns. The FS results were not influenced by etching protocols, while the Weibull modulus was, with the 5%HF groups being the most reliable (m: 5.63/6.70), while C and HF10%60s (m: 2.78/2.73) were the least reliable. All fractures originated from surface defects on the treated side of specimens. The 5%HF groups showed higher µSBS (20 s: 21.35 ± 4.70 MPa; 60 s: 23.50 ± 4.27 MPa) than the 10%HF groups (20 s: 14.51 ± 2.47 MPa; 60 s: 16.54 ± 3.12 MPa) and C (6.46 ± 2.71 MPa). The most prevalent failure pattern was "mixed" for etched groups, and "adhesive" for C. Etching protocols affect the evaluated properties by roughening materials' surface and, in some cases, regularizing surface defects. The best overall outcomes were achieved when applying 5%HF. [ABSTRACT FROM AUTHOR]

In this study, we utilized Selective Laser Melting (SLM) technology to fabricate a magnesium alloy, and subsequently subject it to micro-arc oxidation treatment. We analyzed and compared the microstructure, elemental distribution, wetting angle, and corrosion resistance of the SLM magnesium alloy both before and after the micro-arc oxidation process. The findings indicate that the SLM magnesium alloy exhibits surface porosity defects ranging from 2% to 3.2%, which significantly influence the morphology and functionality of the resulting film layer formed during the micro-arc oxidation process. These defects manifest as pores on the surface, leading to an uneven distribution of micropores with varying sizes across the layer. The surface roughness of the 3D-printed magnesium alloy exhibits a high roughness value of 180 nanometers. The phosphorus (P) content is lower within the film layer compared to the surface, suggesting that the Mg3(PO4)2 phase predominantly resides on the surface, whereas the interior is primarily composed of MgO. The micro-arc oxidation process enhances the hydrophilicity and corrosion resistance of the SLM magnesium alloy, thereby potentially endowing it with bioactivity. Additionally, the increased surface roughness post-treatment promotes cell proliferation. However, certain inherent defects present in the SLM magnesium alloy samples negatively impact the improvement of their corrosion resistance. [ABSTRACT FROM AUTHOR]

The present study investigates the formation mechanism of black spot defects on the surface of industrial continuously hot-dip galvanized Zn-2Al-1.5Mg coatings. Electrochemical experiments and neutral salt spray tests are conducted to study the corrosion resistance of the black spot defects and their influence on the corrosion mechanism of the coatings. The results show that the enrichment of Mg elements within the coating is the fundamental cause of the formation of this defect. The enrichment of Mg elements leads to a reduction in the size of primary Zn, an increase in the proportion of eutectic structures and the MgZn2 within the defective coatings. Consequently, the defective coatings exhibit the higher surface hardness and, after skin pass rolling, display the different reflective properties compared to surrounding coatings. The black spots feature is attributed to the formation of oxide film containing MgO. The electrochemical test results indicate that black spot defect exhibits enhanced corrosion resistance due to the lower Volta potential difference (VPD) between each phase on its surface. Moreover, the fine and dispersed cathodes not only avoid the occurrence of extremely pH sites, but also facilitate the formation of uniform distributed corrosion products with high protective ability. In the 600-h neutral salt spray experiments, Zn-2Al-1.5Mg coatings with black spot defects exhibit enhanced corrosion resistance, which is attributed to the Mg enrichment delaying the decomposition of highly protective corrosion products. [ABSTRACT FROM AUTHOR]

Lead halide perovskite nanocrystals (LHP NCs) are generally prone to surface defect formation during the purification process, resulting in a reduced photoluminescence (PL) quantum yield. The purification of LHP NCs using antisolvents leads to the detachment of surface atoms and ligandsin the form of alkylammonium‐halides or A‐carboxylates (A: Cs, methylammonium, MA, or formamidinium, FA. Currently, intense research is being carried out to improve the surface stability of LHP NCs using various long‐chain organic ligands that strongly bind to the surface of NCs. Herein, the findings on the higher surface stability of hybrid (MAPbBr3 and FAPbBr3) LHP NCs compared to that of inorganic CsPbBr3 NCs against purification with polar antisolvents are reported. It is discovered that the CsPbBr3 NC surface stability can be enhanced (reaching that of hybrid perovskite NCs) by the incorporation of a small amount of MA or FA A‐site organic cations into their lattice, corroborated by the evidence that the PL quantum yield of mixed A‐cation CsxFA1‐xPbBr3 and CsxMA1‐xPbBr3 NCs remains unaffected after several purification cycles. It is hypothesized that this is attributed to hydrogen bonding between the organic A‐site cations and the neighboring halides on the surface. These findings are not only fundamentally important but are also expected to have wide implications in the field of metal‐halide perovskite optoelectronics. [ABSTRACT FROM AUTHOR]

Real-time defect detection is required to efficiently control the quality of aluminium. However, aluminium defects have the characteristics of small-size, low contrast, and multiscale variations, which pose great challenges to defect detection. This article aims to improve the defect detection accuracy and propose an effective multiscale enhancement network with attention mechanism for aluminium defect detection (AMMENet). First, to capture key features and mitigate interference from the background, a pluggable parallel residual attention module (PRAM) is proposed for the feature extraction network. To compensate for the loss of deep features, a multilevel semantic enhancement module (C2f-MFF) is proposed to fuse multiscale feature maps. Finally, the model was applied to the Tianchi Aluminium Surface Defect Dataset (TC-ASDD) for ablation experiments and comparisons. The experimental results show that the mean average precision (mAP@0.5) of the proposed AMMENet is 73.6% with a real-time detection speed of 66.2 frames per second (FPS). Compared with YOLOv8 baseline network, AMMENet improves mAP@0.5 by 2.8% with only a slight loss in speed. Moreover, AMMENet is superior to the state-of-the-art detection methods in terms of detection accuracy. [ABSTRACT FROM AUTHOR]

The optical properties of quantum dots are significantly influenced by photoactivation. However, the progress in the development of photoactivation carbon dot (CDs) is still stagnant. Herein, a method for preparing photoactivated CDs/NiFe2O4 by introducing affluent defects onto the surface of CDs through modification with NiFe2O4, extremely filling the gap of photoactivated CDs is proposed. Interestingly, a fantastic fluorescence detection strategy in a unique “OFF‐ON‐OFF” mode, combined with Ag+‐assisted fluorescence enhancement, to establish a dual‐channel regulation mechanism for ultra‐sensitive detection of Hg2+ is first proposed. By increasing surface traps and non‐radiative recombination, defect‐induced manipulation on the surface of CDs creates favorable conditions for enhancing photoactivation capacity. Unexpectedly, the CDs/NiFe2O4 shows a 25‐fold enhancement in fluorescence intensity after exposure to UV‐lamp. Compared to CDs/NiFe2O4, Ag+‐assisted photoactivation CDs/NiFe2O4 exhibits superior selectivity and sensitivity for Hg2+ detection, with low detection limits of 0.7 nM. Moreover, TiO2@CDs/NiFe2O4 catalyst is successfully prepared by anchoring CDs/NiFe2O4 onto the surface of TiO2, which demonstrates efficient degradation of tetracycline within 90 min under visible light irradiation, with a degradation rate of 98.3%. This work first provides a novel defects modification strategy for developing highly active photoactivated CDs technology that is significant for future environmentally sensitive applications. [ABSTRACT FROM AUTHOR]

Light‐emitting diodes (LEDs) based on perovskite quantum dots (QDs), abbreviated as P‐QLEDs have been regarded as significantly crucial emitters for lighting and displays. Efficient and stable P‐QLEDs still lack ideal electron transport materials (ETM), which could efficiently block hole, transport electron, reduce interface non‐radiative recombination and possess high thermal stability. Here, we report 2,4,6‐Tris(3′‐(pyridine‐3‐yl) biphenyl‐3‐yl)‐1,3,5‐triazine (TmPPPyTz, 3P) with strong electron‐withdrawing moieties of pyridine and triazine to modulate the performance of P‐QLEDs. Compared with commonly used 1,3,5‐Tris(1‐phenyl‐1H‐benzimidazol‐2‐yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non‐radiative recombination caused by the Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole‐blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of 3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P‐QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2 % and an operational lifetime T50 of 3220 hours at an initial luminance of 100 cd m−2, which is 151 % and about 11‐fold improvement compared to control devices (EQE=20 %, T50=297 hours), respectively. These results provide a new concept for constructing the efficient and stable P‐QLEDs from the perspective of selective ETM. [ABSTRACT FROM AUTHOR]

This paper focuses on the use of catalysts generated from metal–organic frameworks (MOFs) for the degradation of toluene in a linked non-thermal plasma/photocatalytic process. The porous tri-metal oxide catalyst (MCNOx) was derived from the metal organic framework (MOF-74) via an in situ pyrolysis strategy utilizing Mn-doped CoNi-MOF-74 as the precursor. The resulting MCNOx material exhibits a unique series of surface defects, which significantly enhances its catalytic activity. We found that MCNOx materials, due to their high specific surface area, regular porous structure, and excellent reducibility, can synergize well with NTP in the complete decomposition of toluene, which makes the NTP coupled catalytic system have better catalytic activity and CO2 selectivity. The toluene conversion temperature of T90 in the NTP synergistic thermocatalytic system was 250 °C for the 5MCNOx catalyst, which was also much higher than that of 1MCNOx (256 °C), 10MCNOx (258 °C), CNOx (270 °C), and 5MCNOx catalyst in the monocatalytic system (270 °C). In addition, the catalytic stability of MOF-derived MCNOx oxides and the influence of water vapor on catalytic activity were investigated, confirming their excellent catalytic performance. Finally, the importance of Mn doping in improving toluene oxidation activity on MOF-74 derived CNOx has been demonstrated, providing a viable strategy for developing a toluene oxidation catalyst. [ABSTRACT FROM AUTHOR]