A5100620527- Semiconductor Quantum Structures and Devices
- Advanced Semiconductor Detectors and Materials
- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Superconducting and THz Device Technology
- Physics of Superconductivity and Magnetism
- Dark Matter and Cosmic Phenomena
- Diamond and Carbon-based Materials Research
- Ultrasonics and Acoustic Wave Propagation
- Particle physics theoretical and experimental studies
- Advanced Battery Technologies Research
- GaN-based semiconductor devices and materials
- Quantum Dots Synthesis And Properties
- Semiconductor materials and devices
- Neutrino Physics Research
- Photonic and Optical Devices
- Radiation Detection and Scintillator Technologies
- Structural Health Monitoring Techniques
- Muscle activation and electromyography studies
- Prosthetics and Rehabilitation Robotics
- Semiconductor Lasers and Optical Devices
- Supercapacitor Materials and Fabrication
- Advanced battery technologies research
- X-ray Diffraction in Crystallography
- Particle Detector Development and Performance
SLAC National Accelerator Laboratory
2017-2025
Samsung (South Korea)
2021-2025
Stanford Synchrotron Radiation Lightsource
2017-2025
Stanford University
2016-2025
Jeonbuk National University
2025
Seoul National University
2012-2024
Korea Research Institute of Standards and Science
2012-2024
Gyeongsang National University
2007-2024
Yonsei University
2018-2024
The University of Tokyo
2024
The demand for flexible and wearable electronic devices is increasing due to their facile interaction with human body. Flexible, stretchable sensors can be easily mounted on clothing or directly attached onto the Especially, highly sensitive strain are needed motion detection. Here, we report flexible, based nanocomposite of silver nanowire (AgNW) network PDMS elastomer in form sandwich structure (i.e., AgNW thin film embedded between two layers PDMS). network-elastomer show strong...
The effect of an electron blocking layer (EBL) on the efficiency droop in InGaN/GaN multiple quantum well light-emitting diodes (LEDs) is investigated. At low current density, LEDs with a p-AlGaN EBL show higher external (EQE) than without EBL. However, EQE as injection density increased. improved at high attributed to increased hole efficiency.
Abstract Poly(ethylene oxide) (PEO)‐based solid electrolytes are expected to be exploited in solid‐state batteries with high safety. Its narrow electrochemical window, however, limits the potential for voltage and energy density applications. Herein oxidation behavior of PEO failure mechanisms LiCoO 2 ‐PEO studied. It is found that although pure it starts oxidize at a above 3.9 V versus Li/Li + , decomposition products have appropriate Li conductivity unexpectedly form relatively stable...
Abstract The multiscale chemomechanical interplay in lithium‐ion batteries builds up mechanical stress, provokes morphological breakdown, and leads to state of charge heterogeneity. Quantifying the complex composite electrodes with resolution constitutes a frontier challenge precisely diagnosing fading mechanism batteries. In this study, hard X‐ray phase contrast tomography, capable nanoprobing thousands active particles at once, enables an unprecedented statistical analysis transformation...
Seventeen Cu complexes with formal oxidation states ranging from CuI to CuIII are investigated through the use of multiedge X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations. Analysis reveals that metal–ligand bonding in high-valent, formally species is extremely covalent, resulting K-edge L2,3-edge spectra whose features have energies complicate physical state assignment. Covalency analysis data all significantly diminished d-character their lowest...
Catching a copper nitrene Nitrogen typically forms three bonds in its stable compounds. If only one bond is available, the resultant electron-deficient can react rapidly with hydrocarbons to fill out valence shell. Metal-stabilized nitrenes have been widely implicated carbon-nitrogen bond-forming reactions, but putative intermediates rarely synthesized directly. Carsch et al. now report preparation of complex from an azide precursor. X-ray absorption and diffraction studies support triplet...
Deep sodium extraction/insertion of cathodes usually causes undesired Jahn-Teller distortion and phase transition, both which will reduce structural stability lead to poor long-cycle reliability. Here we report a zero-strain P2- Na2/3 Li1/6 Co1/6 Mn2/3 O2 cathode, in the lithium/cobalt substitution contributes reinforcing host structure by reducing Mn3+ /Mn4+ redox, mitigating distortion, minimizing lattice change. 94.5 % Na+ unit can be reversibly cycled with charge cut-off voltage 4.5 V...
P2-Na0.67Ni0.33Mn0.67O2 represents a promising cathode for Na-ion batteries, but it suffers from severe structural degradation upon storing in humid atmosphere and cycling at high cutoff voltage. Here we propose an situ construction to achieve simultaneous material synthesis Mg/Sn cosubstitution of Na0.67Ni0.33Mn0.67O2 via one-pot solid-state sintering. The materials exhibit superior reversibility moisture insensitivity. In-operando XRD reveals essential correlation between stability phase...
The Korea Invisible Mass Search (KIMS) experiment presents new limits on the weakly interacting massive particle (WIMP)-nucleon cross section using data from an exposure of 3409 kg·d taken with low-background CsI(Tl) crystals at Yangyang Underground Laboratory. most stringent limit spin-dependent interaction for a pure proton case is obtained. DAMA signal region both spin-independent and interactions WIMP masses greater than 20 GeV/c2 excluded by single crystal scintillators.Received 3 April...
New limits are presented on the cross section for weakly interacting massive particle (WIMP) nucleon scattering in KIMS $\mathrm{CsI}(\mathrm{T}\ensuremath{\ell})$ detector array at Yangyang Underground Laboratory. The exposure used these results is $24\text{ }524.3\text{ }\text{ }\mathrm{kg}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{days}$. Nuclei recoiling from WIMP interactions identified by a pulse shape discrimination method. A low energy background due to alpha emitters crystal...
Acoustoelasticity, or the change in elastic wave speeds with stress, is a well-studied phenomenon for bulk waves. The effect of stress on Lamb waves not as well understood, although it clear that anisotropic stresses will produce anisotropy dispersion curves. Here theory acoustoelastic propagation developed isotropic media subjected to biaxial, homogeneous field. It shown that, expected, curves anisotropically most stresses, modes, and frequencies. Interestingly, some mode-frequency...
Abstract Surface lattice reconstruction is commonly observed in nickel-rich layered oxide battery cathode materials, causing unsatisfactory high-voltage cycling performance. However, the interplay of surface chemistry and bulk microstructure remains largely unexplored due to intrinsic structural complexity lack integrated diagnostic tools for a thorough investigation at complementary length scales. Herein, by combining nano-resolution X-ray probes both soft hard regimes, we demonstrate...
Reliability quantification is a critical and necessary process for the evaluation assessment of any inspection technology that may be classified either as nondestructive or structural health monitoring technique. Based on sensitivity characterization techniques, appropriate processes have been developed established reliability their performance with respect to damage/flaw detection in materials structures. However, case methods, no such well-defined general applicable approaches neither...
Abstract Temporal interference (TI) stimulation was recently proposed that allows for the of deep brain structures with neocortical regions being minimally stimulated. For human modulation, TI current patterns are known to be considerably affected by complex head, and thus, it is hard deliver a specific region. In this study, we optimized scalp electrode configurations injection currents can maximum region, head right hippocampus in considering real anatomical each individual. Three...
Abstract Aqueous Zn‐ion battery is a promising technology for electrochemical energy storage. The formation of Zn dendrites, however, can jeopardize the cell cycle life and thus, hinders industrial adoption this technology. A fundamental understanding kinetic mechanisms crucial improving battery. Here, in situ operando X‐ray microscopy methods are utilized to visualize plating stripping behaviors under different conditions. It demonstrated that substrate curvature, local morphology,...
The manufacturing of commercial lithium-ion batteries (LIBs) involves a number sophisticated production processes. Various cell defects can be induced, and, depending on their structural and chemical characteristics, they could lead to acute failure and/or chronic degradation. Although tremendous efforts have been devoted develop robust quality control (QC) procedure, the functional role is not well understood. Here, we address this question through systematic experimental study 18650-type...
Single-crystalline nickel-rich cathodes are a rising candidate with great potential for high-energy lithium-ion batteries due to their superior structural and chemical robustness in comparison polycrystalline counterparts. Within the single-crystalline cathode materials, lattice strain defects have significant impacts on intercalation chemistry and, therefore, play key role determining macroscopic electrochemical performance. Guided by our predictive theoretical model, we systematically...