A5071892233- 2D Materials and Applications
- Graphene research and applications
- Advanced Photocatalysis Techniques
- Electrocatalysts for Energy Conversion
- Perovskite Materials and Applications
- MXene and MAX Phase Materials
- Ga2O3 and related materials
- GaN-based semiconductor devices and materials
- Quantum Dots Synthesis And Properties
- Diamond and Carbon-based Materials Research
- Electronic and Structural Properties of Oxides
- Advanced battery technologies research
- Copper-based nanomaterials and applications
- Boron and Carbon Nanomaterials Research
- Force Microscopy Techniques and Applications
- Supercapacitor Materials and Fabrication
- Neuroscience and Neural Engineering
- Advanced Electron Microscopy Techniques and Applications
- Advanced Memory and Neural Computing
- Advancements in Battery Materials
- Advanced Sensor and Energy Harvesting Materials
- CO2 Reduction Techniques and Catalysts
- Nanomaterials for catalytic reactions
- Semiconductor materials and devices
- Mechanical and Optical Resonators
Pohang University of Science and Technology
2019-2025
Samsung (South Korea)
2023-2024
Yonsei University
2021
Institute for Basic Science
2019
Despite the Pt-catalyzed alkaline hydrogen evolution reaction (HER) progressing via oxophilic metal-hydroxide surface hybridization, maximizing Pt reactivity alongside operational stability is still unsatisfactory due to lack of well-designed and optimized interface structures. Producing atomically flat two-dimensional nanodendrites (2D-PtNDs) through our 2D nanospace-confined synthesis strategy, this study tackles insufficient interfacial contact effect during HER catalysis by realizing an...
The Haber-Bosch process for NH3 production is one of the largest global energy consumers. Despite improvements over past century, developing catalysts with enhanced activities and durabilities remains challenging. Ru-based supported on CeO2 are suitable alternatives under mild reaction conditions. Here, we elucidated effects Ru structure physicochemical properties catalytic Ru-CeO2 systems. One-pot syntheses metal–organic frameworks as sacrificial templates were used to prepare single-atom,...
Electrochemical reduction of CO 2 to chemical fuels with a transition metal-based single atom catalyst (SAC) offers promising strategy reduce high catalytic selectivity.
Abstract We demonstrate wafer-scale growth of high-quality hexagonal boron nitride (h-BN) film on Ni(111) template using metal-organic chemical vapor deposition (MOCVD). Compared with inert sapphire substrate, the catalytic facilitates a fast h-BN at relatively low temperature 1000 °C. Wafer-scale Raman E 2g peak full width half maximum (FWHM) 18~24 cm −1 is achieved, which to extent our knowledge best reported for MOCVD. Systematic investigation microstructural and characteristics...
The performance of nanocrystal (NC) catalysts could be maximized by introducing rationally designed heterointerfaces formed the facet- and spatio-specific modification with other materials desired size thickness. However, such are limited in scope synthetically challenging. Herein, we applied a wet chemistry method to tunably deposit Pd Ni on available surfaces porous 2D-Pt nanodendrites (NDs). Using 2D silica nanoreactors house 2D-PtND, an 0.5-nm-thick epitaxial or layer (e-Pd e-Ni) was...
We have achieved heteroepitaxial stacking of a van der Waals (vdW) monolayer metal, 1T'-WTe2, and semiconductor, 2H-WSe2, in which distinctively low contact barrier was established across clean epitaxial vdW gap. Our 1T'-WTe2 films were identified as semimetal by temperature transport showed the robust breakdown current density 5.0 × 107 A/cm2. In comparison with series planar metal contacts, our to possess intrinsic Schottky heights below 100 meV for both electron hole injections,...
Two-dimensional (2D) materials are attracting increasing research interest owing to their distinct tunable physical properties. Moreover, the ubiquitous defects in 2D offer an opportunity tailor electronic Recently, atomic-level structural modification methods for have been developed, further triggering need precise control of defects. Following ground-breaking advancements atomic-scale characterization materials, valuable information on defect-driven properties has published. It is...
Selective doping in semiconductors is essential not only for monolithic integrated circuity fabrications but also tailoring their properties including electronic, optical, and catalytic activities. Such active dopants are essentially point defects the host lattice. In atomically thin two-dimensional (2D) transition-metal dichalcogenides (TMDCs), roles of such particularly critical addition to large surface-to-volume ratio, because bond dissociation energy relatively weaker, compared...
With the advent of foldable electronics, it is necessary to develop a technology ensuring foldability when circuit lines are placed on topmost substrate rather than in neutral plane used present industry. Considering potential technological impacts, conversion conventional printed boards ones most desirable achieve circuitry. This study realizes this unconventional concept by coating an ultrathin anisotropic conductive film (UACF) metal board. presents rapid large-area synthesis hydrogenated...
Abstract Remarkable improvements in both structural and optical properties of wafer-scale hexagonal boron nitride (h-BN) films grown by metal-organic chemical vapor deposition (MOCVD) enabled high-temperature post-growth annealing is presented. The enhanced crystallinity homogeneity the MOCVD-grown h-BN at 1050 °C attributed to solid-state atomic rearrangement during thermal 1600 °C. In addition, appearance photoluminescence excitonic transitions as well enlarged band gap were observed for...
We report wafer-scale growth of atomically thin, three-dimensional (3D) van der Waals (vdW) semiconductor membranes. By controlling the kinetics in near-equilibrium limit during metal-organic chemical vapor depositions MoS2 and WS2 monolayer (ML) crystals, we have achieved conformal ML coverage on diverse 3D texture substrates, such as periodic arrays nanoscale needles trenches quartz SiO2/Si substrates. The properties, channel resistivity photoluminescence, are verified to be seamlessly...
We present resistive switching (RS) behavior of few-layer hexagonal boron nitride (h-BN) mediated by defects and interfacial charge transfer. Few-layer h-BN is grown metal–organic chemical vapor deposition used as active RS medium in Ti/h-BN/Au structure, exhibiting clear bipolar fast characteristics about ∼25 ns without an initial electroforming process. Systematic investigation on microstructural the reveals that there are structural such homoelemental B–B bonds at grain boundaries...
Point defects dictate various physical, chemical, and optoelectronic properties of two-dimensional (2D) materials, therefore, a rudimentary understanding the formation spatial distribution point is key to advancement in 2D material-based nanotechnology. In this work, we performed demonstration directly probe 2H-MoTe2 monolayers that are tactically exposed (i) 200 °C-vacuum-annealing (ii) 532 nm-laser-illumination; accordingly, utilize deep learning algorithm classify quantify generated...
While two-dimensional (2D) hexagonal boron nitride (h-BN) is emerging as an atomically thin and dangling bond-free insulating layer for next-generation electronics optoelectronics, its practical implementation into miniaturized integrated circuits has been significantly limited due to difficulties in large-scale growth directly on epitaxial semiconductor wafers. Herein, the realization of a wafer-scale h-BN van der Waals heterostructure with 2 in. AlGaN/GaN high-electron mobility transistor...
Abstract Growing demands for comprehending complicated nano-scale phenomena in atomic resolution has attracted in-situ transmission electron microscopy (TEM) techniques understanding their dynamics. However, simple to safe TEM sample preparation observation been limited. Here, we suggested the optical based micro-manipulating system transferring samples. By adopting our manipulator system, several types of samples from nano-wires plate-like thin were transferred on micro-electro mechanical...
Interest in carbon nanomaterials for energy storage systems such as supercapacitors has enormously risen due to their attractive electrical conductivity, chemical inertness, and charge capacity. The reduction of graphitic oxide is a versatile procedure prepare 3D graphene. Despite many green methods, the dynamics behind ultrafast thermal graphitization have remained elusive. Here, we demonstrate an effort understand mechanism under induced by electromagnetic radiation probably via Ar+ cation...
Point defects often appear in two-dimensional (2D) materials and are mostly correlated with physical phenomena. The direct visualisation of point defects, followed by statistical inspection, is the most promising way to harness structure-modulated 2D materials. Here, we introduce a deep learning-based platform identify 2H-MoTe2: synergy unit cell detection defect classification. These processes demonstrate that segmenting detected hexagonal into two cells elaborately cropped cells: further...
Functional h-BN (hexagonal boron nitride) has been prepared via the incorporation of transition metal (TM) impurities like nanoparticles and single atoms. Herein, scanning transmission electron microscopy (STEM) combined with density functional theory (DFT) was employed to study Ta-, Co-, Ni-, Ir-decorated monolayers provide an overview their preferential site occupancies morphological evolutions on h-BN. Ta, Ni, Ir, Co atoms are all positioned nitrogen h-BN; however DFT predicts occupancy...
Two-dimensional (2-D) hexagonal boron nitride (h-BN) has attracted considerable attention for deep ultraviolet optoelectronics and visible single photon sources, however, realization of an electrically-driven light emitter remains challenging due to its wide bandgap nature. Here, we report emission with a red-shift under increasing electric field from few layer h-BN by employing five-period Al2O3/h-BN multiple heterostructure graphene top electrode. Investigation electrical properties...
Abstract The performance of nanocrystal (NC) catalysts could be maximized by introducing rationally designed heterointerfaces formed the facet‐ and spatio‐specific modification with other materials desired size thickness. However, such are limited in scope synthetically challenging. Herein, we applied a wet chemistry method to tunably deposit Pd Ni on available surfaces porous 2D−Pt nanodendrites (NDs). Using 2D silica nanoreactors house 2D‐PtND, an 0.5‐nm‐thick epitaxial or layer ( e ‐ ‐Ni...
Abstract We report atomic layer-by-layer epitaxial growth of van der Waals ( vdW ) semiconductor superlattices (SLs) with programmable stacking periodicities, composed more than two kinds dissimilar transition-metal dichalcogenide monolayers (MLs), such as MoS 2 , WS and WSe . The kinetics-controlled epitaxy in the near equilibrium limit by metalorganic chemical vapour depositions enables to achieve accurate ML-by-ML stacking, free interlayer mixing, resulting tunable two-dimensional (2D)...