Nano Convergence最新文献

Integrating carbon nanomaterials into solar energy technologies has emerged as a promising strategy to improve efficiency, scalability, and sustainability. Although graphene has excellent carrier mobility, electrical conductivity, and optical transparency, graphene derivatives such as graphene oxide (GO) and reduced graphene oxide (rGO) suffer from significant structural defects and disruption of the sp²-hybridized carbon lattice caused by oxidative processing, severely limiting their electronic and optoelectronic performances. To address these limitations, minimally oxidized graphene (MOG), which includes non-oxidized graphene flakes (NOGFs) and low-oxidized graphene quantum dots (GQDs), has been developed via a nondestructive approach based on ion or molecular intercalation followed by liquid-phase exfoliation. These materials retain the integrity of a π-conjugated network and offer tunable functionalities and solution processability. NOGFs exhibit high conductivity, broadband light absorption, and thermal stability, making them ideal materials for use in solar cell electrodes, photothermal absorbers, and photocatalytic scaffolds. GQDs with tunable bandgaps and abundant functional groups serve as interfacial modifiers in solar cells and as active sites for photocatalysis. This review summarizes recent advances in MOG, focusing on structure–property–performance relationships and applications in solar energy conversion. A comparative evaluation with conventional GO/rGO-based systems is presented along with future directions toward developing high-efficiency graphene-enabled solar technologies.

A 3D motor neuron (MN) spheroid has been developed to investigate neurodegenerative and neuromuscular junction (NMJ) disease. However, core necrosis and reduced neurogenesis, impairing neural network formation, were observed as the MN spheroid matured. In this study, to enhance neural network formation, a biohybrid MN spheroid composed of neural cells/reduced graphene oxide (rGO)/human umbilical vein endothelial cells (HUVECs) was generated for the first time and applied to 3D biosensing system for MNJ disease. By incorporating rGO and HUVECs at the onset of human neural stem cell (hNSC) culture, rGO and HUVECs were evenly distributed within MN spheroid generated by differentiation of hNSC, which improved oxygen- and nutrient- supply by reduction of core necrosis, and enhanced neurogenesis. The fabricated biohybrid MN spheroid improved neural network formation and electrophysiological signal. This method was also applied to generate biohybrid cerebral organoids from human induced pluripotent stem cells (hiPSCs), emphasizing its versatility for diverse 3D neural models. Then, a 3D NMJ biosensing system was fabricated by positioning the biohybrid MN spheroid with muscle bundles to evaluate its utility in neuromuscular disease modeling. Biohybrid MN spheroids generated from induced pluripotent stem cells of sporadic amyotrophic lateral sclerosis (ALS) patients were used to make NMJ. Reduced contraction of the connected muscle bundle due to ALS could be restored by upon treatment with the bosutinib, ALS drug, demonstrating the potential use for drug screening. The method to generate biohybrid spheroid can be applied to generation of various biohybrid brain organoids, and the proposed 3D NMJ biosensing system can be used to drug screening of diverse neuromuscular diseases.

ZnMgO nanoparticles (ZMO NPs) are widely used as electron transport layers in optoelectronic devices such as light-emitting diodes (LEDs) and photodiodes (PDs) primarily because of their facile synthesis and excellent electron transport properties. However, the surface hydroxyl groups (‒OH) on the ZMO NPs introduce charge traps, inhibit electron transport, and reduce device stability, particularly under ambient humidity and oxygen. Therefore, in this study, an alcohol treatment (AT) method was developed to remove surface ‒OH via proton transfer to effectively reduce trap states and dipole moments and enhance surface passivation. Quantum-dot-based LEDs and PDs fabricated using the AT-based ZMO NPs exhibited improved current density, luminance, and external quantum efficiency compared to the untreated devices. Notably, the methanol-treated devices achieved an operational lifetime of approximately 28 h under ambient conditions, representing a substantial advancement in device stability and performance. The AT approach is a simple and effective strategy for optimizing the ZMO NPs for next-generation optoelectronic applications.

Aiming for atomic-scale precision alignment for advanced semiconductor devices, area-selective atomic layer deposition (AS-ALD) has garnered substantial attention because of its bottom-up nature that allows precise control of material deposition exclusively on desired areas. In this study, we develop a surface treatment to hinder the adsorption of Si precursor on metal surfaces by using a vapor-phase functionalization of bulky phosphonic acid (PA) self-assembled monolayers (SAMs). Through the chemical vapor transport (CVT) method, the bulky solid PA inhibitor with a fluorocarbon terminal group was effectively vaporized, and the conditions for maximizing the blocking effect of the inhibitor were confirmed by optimizing the process temperature and dwelling time. The unintended PA inhibitors adsorbed on SiO₂ surfaces during the CVT process were selectively removed by post-HF treatment, thereby leading to selective deposition of SiO₂ thin films only on SiO₂ substrates. As a results, SiO₂ film growth on the PA SAM/HF-treated TiN surfaces was suppressed by up to 4 nm with just a single exposure to the long-chain inhibitor, even during the ALD process using highly reactive O₃ reactants. The proposed approach paves the way for highly selective deposition of dielectrics on dielectrics (DoD).

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Lithium metal batteries (LMBs) hold immense potential as next-generation energy storage systems due to their exceptionally high theoretical energy density. However, their commercialization is hindered by persistent interfacial instabilities that accelerate capacity degradation and limit cycle life. A major challenge lies in the solid-electrolyte interphase (SEI), whose composition and structure critically influence lithium deposition behavior, electrolyte stability, and overall battery performance. This review examines key aspects of SEI stability and its impact on battery performance, highlighting recent advancements in electrolyte engineering and surface modification strategies aimed at enhancing interfacial stability. Beyond laboratory-scale optimizations, we discuss key considerations for translating these advancements into industrial applications, highlighting the importance of practical testing protocols to bridge the gap between fundamental research and real-world deployment.

Pnictide-based quantum dots (QDs) have emerged as promising materials for next-generation infrared photodetectors due to their superior physical and electrical properties. Among them, InAs and InSb QDs are particularly attractive for their tunable bandgaps in the short-wave infrared (SWIR) region, high carrier mobility, and compatibility with solution-based, large-area, and low-cost fabrication processes. This review discusses recent advancements in the synthesis of InAs and InSb QDs, focusing on precursor strategies and surface engineering techniques to enhance their optical and electronic properties. Additionally, we explore their integration into infrared photodetectors, analyzing current performance and limitations. Finally, we outline future research directions aimed at further enhancing material properties and device performance, paving the way for the broader adoption of III–V QDs in next-generation infrared technologies.

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Efficient monolithic perovskite/Si tandem solar cells require a robust recombination junction (RJ) with excellent electrical and optical properties. This study introduces an interface engineering method using an organic sacrificial layer to enable effective monolithic integration. An ultrathin layer of poly(3,4-ethylene-dioxythiophene):polystyrene sulfonate (PEDOT:PSS) is inserted between the transparent conductive oxide recombination layer and the hole transport layer (HTL) of a methylammonium lead iodide (MAPbI₃)-based perovskite top cell. This layer restores junction functionality and enables charge transfer between sub-cells via efficient carrier recombination at the RJ, which electrically connects the two cells. Acting as a sacrificial layer, PEDOT:PSS temporarily prevents resistive SiO_x formation and improves interface quality. High-resolution transmission electron microscopy and X-ray photoelectron spectroscopy confirm suppression of SiO_x growth during HTL annealing. Moreover, the Cu-doped NiO_x HTL fabrication method proves critical, where process optimization improves electrical contact. Combined with PEDOT:PSS interface engineering, these enhancements promote efficient recombination by tuning interfacial energy levels and increasing band bending at the RJ. As a result, tandem devices comprising an aluminum back-surface field p-type homojunction Si bottom cell and a p-i-n perovskite top cell achieve 21.95% power conversion efficiency and an 81.3% fill factor —among the highest reported for monolithic perovskite/Si tandem solar cells.

Infections involving antibiotic-resistant bacteria have become a major problem. Pathogenic bacteria use mechanisms such as drug target bypass, target modification, and biofilm formation to evade treatment. To respond to these problems, antibacterial research using metal and metal oxide nanoparticles is currently active. Nanoparticles treat bacterial infections through reactive oxygen species generation or antibacterial ion release. However, their application has faced problems related to human compatibility, as they react non-specifically, targeting both mammalian and bacterial cells. In addition, ZnO nanoparticles show low antibacterial activity against Gram-negative bacteria. Thus, the demand for antibacterial substances with enhanced specificity and improved efficacy is increasing. We bound gold to the surface of ZnO nanoparticles, enabling photocatalytic and photothermal actions through visible light irradiation. To improve bacterial specificity, Concanavalin A (Con A), a lectin that can specifically target bacterial membrane lipopolysaccharides, was conjugated with the nanoparticles. We showed that Con A-conjugated Au/ZnO nanoparticles (Au/ZnO-Con A) exhibit photocatalytic and photothermal effects under white light, enhancing their antibacterial ability, and through enhanced specificity, increased antibacterial and anti-biofilm abilities were confirmed. The developed particles showed the potential to alleviate antibiotic resistance in a bacterial skin infection model, presenting a new platform for treating bacterial infections.

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Amorphous boron nitride (a-BN) exhibits remarkable electrical, optical, and chemical properties, alongside robust mechanical stability, making it a compelling material for advanced applications in nanoelectronics and photonics. This review comprehensively examines the unique characteristics of a-BN, emphasizing its electrical and optical attributes, state-of-the-art synthesis techniques, and device applications. Key advancements in low-temperature growth methods for a-BN are highlighted, offering insights into their potential for integration into scalable, CMOS-compatible platforms. Additionally, the review discusses the emerging role of a-BN as a dielectric material in electronic and photonic devices, serving as substrates, encapsulation layers, and gate insulators. Finally, perspectives on future challenges, including defect control, interface engineering, and scalability, are presented, providing a roadmap for realizing the full potential of a-BN in next-generation device technologies.

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Developing functional solid polymer electrolytes (SPEs) is crucial for flexible, lightweight, and portable supercapacitors. This work presents an electrospinning approach to fabricate SPEs using poly(vinyl alcohol)-sodium chloride (PVA-NaCl) nanofibers (PNNF). CuNi₂O₃ nanoparticles deposited on nitrogen-doped omnichannel carbon nanofibers (CuNi₂O₃@N-OCCFs), coated onto a carbon cloth (CC), serve as the positive electrode, enhancing faradaic capacitance. Meanwhile, the rationally designed N-OCCFs, also coated onto CC, function as the negative electrode, providing a high-surface-area, and facilitating rapid electron transport. Comprehensive characterization revealed insights into the morphology and chemical composition of both electrodes and the PNNF electrolyte. An all-solid-state asymmetric flexible supercapacitor (AFSC) device, CuNi₂O₃@N-OCCFs-1.5//N-OCCFs-1.5, was assembled using PNNF as both the electrolyte and separator and evaluated against devices employing gel and aqueous electrolytes. The PNNF electrolyte enabled a wider potential window (2.2 V) compared to gel (2.0 V) and liquid (1.8 V) electrolytes. The AFSC achieved an impressive energy density of 63.6 Wh kg⁻¹ at a power density of 1100 W kg⁻¹, with 96.2% capacitance retention after 6000 charge/discharge cycles at 10 A g⁻¹. When two devices were connected in series, they powered a red LED for 5.33 min and a blue LED for 1.43 min, demonstrating practical applicability. This study provides a simple and effective strategy for fabricating high-energy–density AFSCs with excellent cycling stability and broad potential for flexible electronics.

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