DGIST 전자도서관

Enhanced P-type conductivity in Sb2Se3 through alkali and alkaline earth metal doping

2025-03Journal of Materials Chemistry A, v.13, no.12, pp.8507 - 8517

Antimony selenide (Sb2Se3) has recently received much attention as a potential candidate for light absorbers in thin-film photovoltaic technologies because of its earth abundance, nontoxicity, and promising electrical and optical properties. Treatments with alkali and alkaline earth elements have been shown to enhance the performance of conventional thin-film solar cells. In this study, we employ hybrid density functional theory to investigate the electronic structures and defect properties of Sb2Se3 doped with alkali and alkaline earth elements in comparison to those of native undoped Sb2Se3. Our results indicate that undoped Sb2Se3 exhibits slight p-type conductivity and semi-insulating property under Se-rich and Se-poor conditions, respectively, consistent with experimental observations. The calculations further reveal that potassium, magnesium, and calcium act as acceptor dopants in a Se-rich environment, improving the p-type conductivity by preferentially forming antisite defects, whereas sodium has a negligible impact. Notably, calcium substitution at Sb site shows the lowest formation energy and a shallow transition energy level, significantly enhancing p-type conductivity. Given its earth abundance, eco-friendliness, and nontoxicity, thus, calcium presents a promising p-type dopant for improving the conductivity and efficiency of Sb2Se3-based devices. © 2025 The Royal Society of Chemistry.

Energy Consumption Analysis of 5G C-V2X Sensor Sharing for Tele-Operated Driving

2025-03IEEE Access, v.13, pp.42547 - 42558

As autonomous driving technology advances, the demand for unmanned mobility applications continues to grow. However, due to the imperfections in current autonomous driving systems, incidents still occur, highlighting the challenges of full driverless services. Moreover, the computation of complex autonomous driving algorithms requires an on-board computing unit, which consumes a large amount of energy. To address these limitations, tele-operated driving (ToD) has emerged as a promising solution for enhancing autonomous intelligent transportation systems (ITS). By enabling remote entities, such as remote users or servers, to control vehicles and manage edge cases in autonomous driving, ToD combines the benefits of both unmanned mobility and human oversight. To support ToD service, a real-time sensor sharing system for vehicles is essential, and cellular vehicle-to-everything (C-V2X) communication is suitable for the required network connectivity. However, most research has not focused on high-volume data transmission, which is required for sensor sharing systems. Additionally, the energy consumption of C-V2X, which directly impacts the battery efficiency of electric vehicles (EVs) as an example, has not been thoroughly examined. In this paper, we propose an evaluation framework for energy consumption analysis of ToD. Based on this framework, we analyze the energy consumption of vehicle for sensor data transmission over 5G C-V2X under varying channel conditions and multi-user scenarios. We also investigate the extent to which using ToD is energy-saving compared to the energy consumption of an on-board high-performance computing unit. Our findings indicate that the uplink-based sensor sharing system is more energy-efficient than its sidelink-based counterpart. Additionally, sensor sharing for ToD can save more energy of the battery in the vehicle compared to relying on the high-performance on-board computing unit. © 2025 Institute of Electrical and Electronics Engineers Inc.. All rights reserved.

Stable performance for pouch-type all-solid-state batteries enabled by current collector with optimized primer layer

2025-06Materials Science and Engineering: R: Reports, v.164

Sulfide-based all-solid-state batteries (ASSBs) are advancing beyond solid electrolyte development to focus on composite electrode design and scalability for commercialization. Scaling from laboratory prototypes to pilot-scale production of large cells with high-energy density and high-performance ASSBs introduces new challenges. Large-scale electrode development necessitates selection of suitable polymeric binders that are compatible with sulfide electrolytes and exhibit strong binding forces for enhanced longevity. In this regard, we used rubber- and styrene-based polymeric binders in ASSBs and introduced a primer layer on the current collector, combining carbon conductive agents and polyvinylidene fluoride, to improve adhesion to the current collector. This primer layer reduces the binder content, which is an inactive component in the electrode, thereby diversifying Li-ion and electron conduction pathways and enhancing the ionic and electronic conductivity of the composite electrode. Furthermore, the primer layer not only prevents direct contact between the sulfide-based solid electrolyte and the Cu current collector but also blocks interactions between the Cu current collector and vaporized sulfur. By acting as a passivation layer, it effectively suppresses Cu corrosion. Consequently, a pouch-type full cell incorporating a primer layer demonstrated improved initial capacity and higher Coulombic efficiency under non-pressurized conditions. Specifically, the cell retained 80.7 % of its capacity after 100 cycles, demonstrating improved performance compared to uncoated full cells (64.8 %). © 2025 Elsevier B.V.

Current Status and Future Directions in the Development of Digital Therapeutic Interventions for Neurodevelopmental Disorders

ACCEPTClinical Pharmacology and Therapeutics

Innovations in digital technologies have emerged digital therapeutics (DTx) as a novel therapeutic intervention. DTx hold potential as novel theragnostics for disorders with broad diagnostic spectra, including neurodevelopmental diseases (NDDs). In this review, we highlight challenging factors in the successful development and deployment of DTx for NDDs with respect to patients, medical professionals, and manufacturers. We also discuss the implications of these factors and future directions for revitalizing DTx development for NDDs.

The Giese reaction of alkyl bromides using amine carboxyboranes

2025-03Organic Chemistry Frontiers, v.12, no.6, pp.1874 - 1878

Amine carboxyborane enabled efficient halogen atom transfer (XAT) with 1 degrees, 2 degrees, and 3 degrees alkyl bromides, resulting in Giese addition products with various electron-deficient double bonds. Moreover, direct addition of several boryl radicals was also possible using several ligated carboxyboranes.

Magnetic and pH-Sensitive dual actuation of biohybrid microswimmer of targeted drug release suitable for cancer cell microenvironment

2025-06Journal of Science: Advanced Materials and Devices, v.10, no.2

The chemotherapeutic agents most frequently used in cancer treatment often have limited effectiveness because of their low specificity for tumors and poor therapeutic performance. In addition to the aforementioned therapeutic challenges the drug delivery carriers conjugated with the drug encounter early detection and elimination from the immune system before arriving at the affected area continues to be a significant research focus among researchers. To address this prevalent issue, an effective approach has been developed that leverages the physiological differences between normal and tumor tissue to enhance the efficacy of anticancer drugs. This drug delivery system is designed based on pH-sensitive drug release, ensuring targeted release within cancer cells. In the present study, we have developed a drug carrier called as biohybrid magnetic microswimmer (BMM). The BMM was formed through a three-step process: firstly, bacterial surfaces were functionalized with biotinylated PEG which enables the bacteria to escape the phagocytosis process; secondly, the anticancer drug lenalidomide was PEGylated to enhance solubility; and finally, both complexes were conjugated via streptavidin-biotin interaction. The study investigated bond formation, bacterial viability after drug treatment, pH-dependent release, and cytotoxicity in various cell lines (MCF-7 and THP-1 cells), and the results revealed that the concentration of the drug, released from BMM gradually increased as the pH of the solvent decreased from neutral to acidic, mimicking the surrounding environment of normal cells and cancer cells, respectively, which in turn affects the cancer cell viability negatively. Therefore, BMM shows promise in targeted drug delivery, utilizing magnetic manipulation and pH-triggered release, providing advantages that include bacteria's maneuverability and PEG's stealth properties, enhancing drug efficacy. © 2025 Vietnam National University, Hanoi

Twist-Induced Dimensional Crossover and Topological Phase Transitions in Bismuthene Quasicrystals

2025-03Chemistry of Materials, v.37, no.6, pp.2358 - 2366

Twisted bismuthene homojunctions, comprised of a Bi(111) bilayer atop two Bi(110) monolayers, exhibit a distinct growth orientation that is facilitated by self-assembly. Our cross-sectional structural analysis reveals an unexpected growth alignment of Bi(110) layers on transition-metal dichalcogenides, deviating from the anticipated Bi(111) bilayer structure. This self-assembly process, driven by the crystal symmetry interplay, induces a topological phase transition beyond a critical thickness. The dimensional crossover in the Fermi surfaces marks the electronic transition from two-dimensional (2D) Bi(110) to 1D Bi(111) quasicrystals. Additionally, the emergence of the topologically nontrivial band structures, an enhanced 1D carrier density, and a metal-insulator transition through band inversion indicate that the twisted bismuthene quasicrystals are promising candidates for higher-order topological quasicrystalline insulators. These findings pave the way for low-resistance contacts in 2D transistors, advancing the development of next-generation electronic devices. © 2025 American Chemical Society.

An Overview of Flame-Retardant Materials for Triboelectric Nanogenerators and Future Applications

2025-03Advanced Materials, v.37, no.9

Triboelectric nanogenerators (TENGs) have gained significant attention for ability to convert mechanical energy into electrical energy. As the applications of TENG devices expand, their safety and reliability becomes priority, particularly where there is risk of fire or spontaneous combustion. Flame-retardant materials can be employed to address these safety concerns without compromising the performance and efficiency of TENGs. The primary focus of this review is on flame-retardant materials, including polymers, biomaterials, liquid polymers, aerogels, and carbon-based materials. The fundamental properties of these materials for TENG applications are elucidated. The characteristics of each material type are described, along with their potential to boost the safety and performance of TENGs. The importance of flame retardancy in advancing TENG technology can be projected from its usage in wearable electronics, self-powered sensors, and smart textiles. Current challenges such as material compatibility, fabrication complexity, and environmental concerns are addressed, along with proposed strategies for overcoming them. This review underscores the significance of flame-retardant materials in strengthening the functionality and safety of TENG devices, paving the way for their widespread adoption across various industries. © 2025 Wiley-VCH GmbH.

Hybridized nanogenerators: Materials and structural design for improving energy harvesting

ACCEPTMRS Bulletin

As technology advances and enhances modern lifestyles, energy consumption is increasing dramatically. Harnessing energy from ambient sources—such as light, water, wind, and mechanical forces—presents a promising and eco-friendly method for converting renewable energy into usable electrical power. Recent developments in nanogenerators have led to the creation of hybridized nanogenerators, significantly improving overall power generation and providing sufficient energy to support electronic devices essential to today’s technology-driven lifestyle. The latest developments in hybrid nanogenerators are reviewed in this article, with a focus on material fabrication and architectural designs; particularly, emphasis is placed on multifunctional materials capable of harvesting multiple forms of energy. © The Author(s), under exclusive License to the Materials Research Society 2025.

Miniature Li+ solvation by symmetric molecular design for practical and safe Li-metal batteries

ACCEPTNature Energy

Developing high-safety Li-metal batteries (LMBs) with rapid rechargeability represents a crucial avenue for the widespread adoption of electrochemical energy storage devices. Realization of LMBs requires an electrolyte that combines non-flammability with high electrochemical stability. Although current electrolyte technologies have enhanced LMB cyclability, rational electrolyte fabrication capable of simultaneously addressing high-rate performance and safety remains a grand challenge. Here we report an electrolyte design concept to enable practical, safe and fast-cycling LMBs. We created miniature anion–Li+ solvation structures by introducing symmetric organic salts into various electrolyte solvents. These structures exhibit a high ionic conductivity, low desolvation barrier and interface stabilization. Our electrolyte design enables stable, fast cycling of practical LMBs with high stability (LiNi0.8Co0.1Mn0.1O2 cell (twice-excessed Li): 400 cycles) and high power density (pouch cell: 639.5 W kg−1). Furthermore, the Li-metal pouch cell survived nail penetration, revealing its high safety. Our electrolyte design offers a viable approach for safe, fast-cycling LMBs. © The Author(s), under exclusive licence to Springer Nature Limited 2025.

Utility of hypervariable region in hepatitis E virus for genetic evolution analysis and epidemiological studies

2025-02Journal of General Virology, v.106, no.2

Clinical and experimental studies have advanced our understanding of hepatitis E virus (HEV) infection; however, translating the findings to improve prevention and clinical outcomes remains challenging. Phylogenetic analyses of HEV show inconsistencies due to variations in the nucleotide regions studied. This study examined specific HEV regions to facilitate comprehensive molecular and phylogenetic analyses by examining the complete genome and commonly studied partial genome regions. We compared topological similarities between phylogenetic trees and evaluated evolutionary divergence using base substitutions and pairwise distances. The hypervariable region (HVR) showed the closest topology (Robinson–Foulds, Jaccard Robinson–Foulds and clustering information) to the complete genome and a higher mutation rate, resulting in longer branch lengths and clearer genotypic distinctions. Pairwise analysis revealed greater intra- and intergenotypic diversity in the HVR than in other regions. The higher base substitution rate and longer branch lengths of HVR suggest its key role in genotype evolution. Classifying HEV using HVR instead of the other partial genomic regions can reveal subtypes that more accurately reflect the genetic characteristics of HEV. Future research could focus on HVRs to better compare clinical symptoms and genetic features of HEV. © 2025 The Authors.

Construction of NiCoO2-(Ni,Co)Se2 hybrid nanorods as an effective bifunctional interlayer for lithium‑sulfur batteries

2025-03Journal of Energy Storage, v.113

The practical application of lithium‑sulfur (Li[sbnd]S) batteries is hindered by the shuttle effect caused by the dissolution of polysulfides in the electrolyte during the charge-discharge process, and the sluggish kinetic conversion of polysulfides. In this work, we present a novel hybrid material, nanorod-shaped NiCoO2-(Ni,Co)Se2 hybrid (NCOSe), synthesized through simple hydrothermal and further selenization methods. These NCOSe hybrid nanorods were uniformly coated onto a commercial polypropylene (PP) separator via vacuum filtration for application in Li[sbnd]S batteries. In the hybrid structure, the NiCoO2 nanorod component exhibits strong polysulfides adsorption due to its high polarity, while (Ni,Co)Se2 part promotes favorable polysulfides conversion due to superb catalytic conversion properties. Electrochemical testing reveals that the Li[sbnd]S full cell with the bifunctional NCOSe/PP separator delivers an initial specific capacity of 1277 mAh g−1 at a current density of 0.1C (1C = 1675 mA g−1). After 200 cycles at 0.2C, the specific capacity reaches 793 mAh g−1, with a low average capacity decay of just 0.123 % per cycle. With a higher sulfur loading of 3.0 mg cm−2, the cell achieves a specific capacity of 455 mAh g−1 after 220 cycles at 0.5C, and with a maximum sulfur loading of 4.4 mg cm−2 at 0.5C, it still maintains 72 % (311 mAh g−1) of its initial capacity after 400 cycles. This study introduces a novel hybrid material with dual functionalities-enhanced polysulfides adsorption and accelerated polysulfides conversion, offering improved cycling stability of Li[sbnd]S batteries. © 2025 Elsevier Ltd