A5000208797- 2D Materials and Applications
- Graphene research and applications
- Advanced Memory and Neural Computing
- MXene and MAX Phase Materials
- Topological Materials and Phenomena
- Quantum and electron transport phenomena
- Advanced Photocatalysis Techniques
- Electrocatalysts for Energy Conversion
- Ferroelectric and Negative Capacitance Devices
- Advanced Thermoelectric Materials and Devices
- Molecular Junctions and Nanostructures
- Perovskite Materials and Applications
- Surface and Thin Film Phenomena
- Advancements in Battery Materials
- Semiconductor materials and devices
- Photonic and Optical Devices
- Carbon Nanotubes in Composites
- Inorganic Chemistry and Materials
- Plasmonic and Surface Plasmon Research
- Organic and Molecular Conductors Research
- Advanced Sensor and Energy Harvesting Materials
- Neural dynamics and brain function
- Thermal properties of materials
- Chalcogenide Semiconductor Thin Films
- Gas Sensing Nanomaterials and Sensors
Korea Advanced Institute of Science and Technology
2007-2025
University of Toyama
2024
Chungbuk National University
2024
Sungkyunkwan University
2014-2022
Ewha Womans University
2021
Institute for Basic Science
2014-2020
Samsung (South Korea)
2010-2013
Centre National de la Recherche Scientifique
2010-2013
Institut des Sciences Moléculaires d'Orsay
2013
Seoul National University
2010-2013
Artificial van der Waals heterostructures with two-dimensional (2D) atomic crystals are promising as an active channel or a buffer contact layer for next-generation devices. However, genuine 2D heterostructure devices remain limited because of impurity-involved transfer process and metastable inhomogeneous formation. We used laser-induced phase patterning, polymorph engineering, to fabricate ohmic heterophase homojunction between semiconducting hexagonal (2H) metallic monoclinic (1T')...
Despite several years of research into graphene electronics, sufficient on/off current ratio I(on)/I(off) in transistors with conventional device structures has been impossible to obtain. We report on a three-terminal active device, variable-barrier "barristor" (GB), which the key is an atomically sharp interface between and hydrogenated silicon. Large modulation (on/off 10(5)) achieved by adjusting gate voltage control graphene-silicon Schottky barrier. The absence Fermi-level pinning at...
High dimensionality and fading memory for in-sensor reservoir computing are achieved via two-dimensional memristors.
Abstract The large-scale crossbar array is a promising architecture for hardware-amenable energy efficient three-dimensional memory and neuromorphic computing systems. While accessing cell with negligible sneak currents remains fundamental issue in the architecture, up-to-date cells arrays suffer from process device integration (one selector one resistor) or destructive read operation (complementary resistive switching). Here, we introduce self-selective based on hexagonal boron nitride...
Synaptic computation, which is vital for information processing and decision making in neural networks, has remained technically challenging to be demonstrated without using numerous transistors capacitors, though significant efforts have been made emulate the biological synaptic transmission such as short-term long-term plasticity memory. Here, we report computation based on Joule heating versatile doping induced metal-insulator transition a scalable monolayer-molybdenum disulfide (MoS2)...
We report on the successful integration of low-cost, conformal, and versatile atomic layer deposited (ALD) dielectric in Ni–Al2O3–Co magnetic tunnel junctions (MTJs) where Ni is coated with a spin-filtering graphene membrane. The ALD barriers, as thin 0.6 nm, are grown layer-by-layer simple, low-vacuum, ozone-based process, which yields high-quality electron-transport barriers revealed by tunneling characterization. Even under these relaxed conditions, including air exposure interfaces,...
Engineering surface atoms of transition metal dichalcogenides (TMDs) is a promising way to design catalysts for efficient electrochemical reactions including the hydrogen evolution reaction (HER). However, materials processing based on TMDs, such as vacancy creation or edge exposure, active HER, has resulted in insufficient atomic-precision lattice homogeneity and lack clear understanding HER over 2D materials. Here, we report durable effective at atomically defined sites layered...
We report on graphene-passivated ferromagnetic electrodes (GPFE) for spin devices. GPFE are shown to act as spin-polarized oxidation-resistant electrodes. The direct coating of nickel with few layer graphene through a readily scalable chemical vapour deposition (CVD) process allows the preservation an unoxidized surface upon air exposure. Fabrication and measurement complete reference tunneling valve structures demonstrates that is maintained polarizer also presence leads specific sign...
The rectifying Schottky characteristics of the metal-semiconductor junction with high contact resistance have been a serious issue in modern electronic devices. Herein, we demonstrated conversion nature Ni-Si junction, one most commonly used junctions, into an Ohmic low by inserting single layer graphene. achieved from incorporating graphene was about 10(-8) ~ 10(-9) Ω cm(2) at Si doping concentration 10(17) cm(-3).
Diverse synaptic plasticity with a wide range of timescales in biological synapses plays an important role memory, learning, and various signal processing exceptionally low power consumption. Emulating functions by electric devices for neuromorphic computation has been considered as way to overcome the traditional von Neumann architecture which separated memory information units require high consumption their functions. Synaptic are expected conduct complex such image classification,...
Multi-terminal memristor and memtransistor (MT-MEMs) has successfully performed complex functions of heterosynaptic plasticity in synapse. However, theses MT-MEMs lack the ability to emulate membrane potential neuron multiple neuronal connections. Here, we demonstrate multi-neuron connection using a multi-terminal floating-gate (MT-FGMEM). The variable Fermi level (EF) graphene allows charging discharging MT-FGMEM horizontally distant electrodes. Our demonstrates high on/off ratio over 105...
Abstract Spin‐polarized bands in pristine and proximity‐induced magnetic materials are promising building blocks for future devices. Conceptually new memory, logic, neuromorphic devices conceived based on atomically thin the manipulation of their spin‐polarized via electrical optical methods. A critical remaining issue is direct probe optimized use coupling effect van der Waals heterostructures, which requires further delicate design Here, a spin‐selective memtransistor with magnetized...
Neural networks are increasingly used to solve optimization problems in various fields, including operations research, design automation, and gene sequencing. However, these face challenges due the nondeterministic polynomial time (NP)-hard issue, which results exponentially increasing computational complexity as problem size grows. Conventional digital hardware struggles with von Neumann bottleneck, slowdown of Moore's law, arising from heterogeneous system design. Two-dimensional (2D)...
Abstract The advanced patterning process is the basis of integration technology to realize development next-generation high-speed, low-power consumption devices. Recently, area-selective atomic layer deposition (AS-ALD), which allows direct target materials on desired area using a barrier, has emerged as an alternative process. However, AS-ALD remains challenging use for improvement resolution and selectivity. In this study, we report superlattice-based (SAS-ALD) two-dimensional (2D) MoS 2...
Electron scattering at graphene edges is expected to make a crucial contribution the electron transport in nanodevices by producing quantum interferences. Atomic-scale scanning tunneling microscopy (STM) topographies of different edge structures monolayer show that localization electronic density states along C-C bonds, property unique graphene, results interference patterns carbon bond network, whose shapes depend only on structure and not energy.
Doping two-dimensional (2D) semiconductors beyond their degenerate levels provides the opportunity to investigate extreme carrier density-driven superconductivity and phase transition in 2D systems. Chemical functionalization ionic gating have achieved high doping density, but effective ranges been limited ∼1 nm, which restricts use of highly doped semiconductors. Here, we report on electron diffusion from electride [Ca2N]+·e– MoTe2 over a distance 100 nm contact interface, generating an...
Carrier density and temperature-dependent resistivity of graphene grown by chemical vapor deposition (CVD) is investigated. We observe in low mobility CVD device a generic insulating behavior at temperatures, eventually metallic high manifesting nonmonotonic temperature dependent resistivity. This feature strongly affected carrier modulation with the low-density samples exhibiting insulating-like dependence up to higher temperatures than corresponding high-density samples. To explain...
Using first-principles calculations of graphene having high-symmetry distortion or defects, we investigate band gap opening by chiral symmetry breaking, intervalley mixing, in and show an intuitive picture understanding the terms local bonding antibonding hybridizations. We identify that breaking honeycomb lattices is ideal two-dimensional (2D) extension Peierls metal−insulator transition 1D linear lattices. spontaneous Kekule distortion, a 2D version takes place biaxially strained graphene,...
We report on the demonstration of ferromagnetic spin injectors for spintronics which are protected against oxidation through passivation by a single layer graphene. The graphene monolayer is directly grown catalytic chemical vapor deposition pre-patterned nickel electrodes. X-ray photoelectron spectroscopy reveals that even with its monoatomic thickness, still efficiently protects sources in ambient air. resulting passivated electrodes integrated into valves and demonstrated to act as...
Scanning tunneling microscopy (STM) and density functional theory (DFT) calculations were used to investigate the surface morphology electronic structure of graphene synthesized on Cu by low temperature chemical vapor deposition (CVD). Periodic line patterns originating from arrangements carbon atoms passivate interaction between metal substrate graphene, resulting in flawless inherent band pristine graphene/Cu. The effective elimination states passivation is expected contribute growth...