A5066174973- Graphene research and applications
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor materials and devices
- Nanowire Synthesis and Applications
- Quantum and electron transport phenomena
- Molecular Junctions and Nanostructures
- Quantum Mechanics and Applications
- Carbon Nanotubes in Composites
- Mechanical and Optical Resonators
- Plasmonic and Surface Plasmon Research
- Quantum Information and Cryptography
- Photonic and Optical Devices
- 2D Materials and Applications
- Advanced biosensing and bioanalysis techniques
- Surface and Thin Film Phenomena
- Quantum Computing Algorithms and Architecture
- Photonic Crystals and Applications
- Silicon Carbide Semiconductor Technologies
- Semiconductor Quantum Structures and Devices
- ZnO doping and properties
- Quantum Dots Synthesis And Properties
- Topological Materials and Phenomena
- Semiconductor materials and interfaces
- Metamaterials and Metasurfaces Applications
- Supercapacitor Materials and Fabrication
Pohang University of Science and Technology
2016-2024
Samsung (South Korea)
2009-2021
Wonkwang University
2019-2020
Cheongju University
2017
Korea University
2004-2016
Suwon Research Institute
2016
Sungkyunkwan University
2009-2016
Institute for Basic Science
2016
Kongju National University
2015
University of Seoul
1998-2010
The widespread use of thermoelectric technology is constrained by a relatively low conversion efficiency the bulk alloys, which evaluated in terms dimensionless figure merit (zT). zT alloys can be improved reducing lattice thermal conductivity through grain boundary and point-defect scattering, target low- high-frequency phonons. Dense dislocation arrays formed at low-energy boundaries liquid-phase compaction Bi(0.5)Sb(1.5)Te3 (bismuth antimony telluride) effectively scatter midfrequency...
Although two-dimensional monolayer transition-metal dichalcogenides reveal numerous unique features that are inaccessible in bulk materials, their intrinsic properties often obscured by environmental effects. Among them, work function, which is the energy required to extract an electron from a material vacuum, one critical parameter electronic/optoelectronic devices. Here, we report large function modulation MoS2 via ambient gases. The was measured situ Kelvin probe technique and further...
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).
Broadband detection of mid-infrared (IR) photons extends to advanced optoelectronic applications such as imaging, sensing, and telecommunications. While graphene offers an attractive platform for broadband visible/IR photodetection, previous efforts improve its responsivity, example, by integrating light-absorbing colloids or waveguide antenna fabrication, were achieved at the cost reduced photon bandwidth. In this work, we demonstrate room-temperature operation a novel mid-IR photodetector...
We report metal-free synthesis of high-density single-crystal elementary semiconductor nanowires with tunable electrical conductivities and systematic diameter control narrow size distributions. Single-crystal silicon germanium were synthesized by nucleation on nanocrystalline seeds subsequent one-dimensional anisotropic growth without using external catalyst. Systematic the diameters tight distribution doping concentration realized adjusting conditions, such as temperature ratio precursor...
Using the massive MIMIC physiological database, we tried to validate pulse wave analysis (PWA) based on multiparameters model whether it can continuously estimate blood pressure (BP) values single site of one hand. In addition, consider limitation insufficient data acquirement for home user, used arrival time (PAT) driven BP information determine individual scale factors PWA-BP estimation model. Experimental results indicate that accuracy average regression has error standard deviations mmHg...
Despite the direct band gap of monolayer transition metal dichalcogenides (TMDs), their optical gain remains limited because poor light absorption in atomically thin, layered materials. Most approaches to improve TMDs mainly involve modulation active materials or multilayer stacking. Here, we report a method enhance and emission MoS2 simply through design nanostructured substrate. The substrate consisted dielectric nanofilm spacer (TiO2) film. overall photoluminescence intensity from on was...
Due to its direct and narrow band gap, high chemical stability, Seebeck coefficient (1800 μVK(-1)), antimony selenide (Sb2Se3) has many potential applications, such as in photovoltaic devices, thermoelectric solar cells. However, research on the Sb2Se3 materials been limited by low electrical conductivity bulk state. To overcome this challenge, we suggest two kinds of nano-structured materials, namely, diameter-controlled nanowires Ag2Se-decorated nanowires. The photocurrent response Sb2Se3,...
In this paper, the Lorentz transformation of entangled Bell states seen by a moving observer is studied. The calculated observable for four joint measurements turns out to give universal value, $〈\^a\ensuremath{\bigotimes}\mathrm{b\ifmmode \hat{}\else \^{}\fi{}}〉+〈\^a\ensuremath{\bigotimes}{b}^{\ensuremath{'}}〉+〈{a}^{\ensuremath{'}}\ensuremath{\bigotimes}\mathrm{b\ifmmode...
Abstract We investigated the band gap of SiZnSnO (SZTO) with different Si contents. Band engineering SZTO is explained by evolution electronic structure, such as changes in edge states and gap. Using ultraviolet photoelectron spectroscopy (UPS), it was verified that atoms can modify thin films. Carrier generation originating from oxygen vacancies band-gap oxide films addition Si. Since not easy to directly derive amorphous semiconductors, no reports relationship between Fermi energy level...
Abstract Phonons, which are collective excitations in a lattice of atoms or molecules, play major role determining various physical properties condensed matter, such as thermal and electrical conductivities. In particular, phonons graphene interact strongly with electrons; however, unlike usual metals, these interactions between massless Dirac fermions appear to mirror the rather complicated physics those light relativistic electrons. Therefore, fundamental understanding underlying through...
In this study, the possibility of compact modeling in single-electron circuit simulation has been investigated. It is found that each Coulomb island circuits can be treated independently when interconnections between transistors are large enough and a quantitative criterion for condition given. also demonstrated that, those situations, SPICE macromodeling used efficient simulation. The developed macromodel produces results with reasonable accuracy orders magnitude less CPU time than usual...
Two-dimensional (2D) transition metal dichalcogenides (TMDs) have received great attentions because of diverse quantum electronic states such as topological insulating (TI), Weyl semimetallic (WSM) and superconducting states. Recently, the emerged in pressurized TMDs MoTe2 WTe2 become one central issues due to their predicted WSM However, difficulty synthetic control chalcogen vacancies ambiguous magneto transport properties hindered rigorous study on Here, we report emergence...
Bi2-xSbxTe3-ySey has been argued to exhibit both topological surface states and insulating bulk states, but not yet studied with local probes on the atomic scale. Here we report electronic structures of Bi1.5Sb0.5Te1.7Se1.3 using scanning tunnelling microscopy (STM) spectroscopy (STS). Although there is significant disorder due alloying constituent atoms, cleaved surfaces crystals present a well-ordered hexagonal lattice 10 Å high quintuple layer steps. STS results reflect band structure...
We consider the dense coding of entangled qubits shared between two parties, Alice and Bob. The efficiency classical information gain through quantum is also considered for case pairwise maximally qubits. conclude that using can be more efficient when parties communicate whereas N communicate.
The band gap properties of amorphous SiInZnO (a-SIZO) thin-film transistors (TFTs) with different Si concentrations have been studied. electronic structures the films, engineered by controlling content, investigated through changes and edge states. Carrier generation at oxygen vacancies can modify states oxide thin films. suppresses number vacancies-which are carrier sites-so shifts Fermi energy level away from conduction band. It is difficult to derive semiconductors electrical...
We investigated systematic modulation of the Dirac point voltage graphene transistors by changing type ionic liquid used as a main gate dielectric component. Ion gels were formed from liquids and non-triblock-copolymer-based binder involving UV irradiation. With fixed cation (anion), shifted to higher size anion (cation) increased. Mechanisms for designing fully understood using molecular dynamics simulations, which excellently matched our experimental results. It was found that ion sizes...
Nanophotonics capable of directing radiation or enhancing quantum-emitter transition rates rely on plasmonic nanoantennas. We present here a novel Babinet-inverted magnetic-dipole-fed multislot optical Yagi–Uda antenna that exhibits highly unidirectional to free space, achieved by engineering the relative phase interacting surface plasmon polaritons between slot elements. The unique features this nanoantenna can be harnessed for realizing energy transfer from one waveguide another working as...
On the basis of 2-D potential analysis performed while taking into account effective conducting path effect, a new analytical model for threshold voltage in cylindrical surrounding-gate MOSFETs (SGMOSFETs) that contain localized charges is presented. From Poisson's equation based on parabolic approximation, simple and accurate expression derived. The proposed validated using 3-D device simulator, good agreement obtained various dimensions charge distributions. This can be used to investigate...
High performance negative electrode materials for lithium-ion batteries were fabricated using germanium nanowire (GeNW) and graphite nanofiber (GNF) composites prepared by a low-pressure chemical vapor deposition (CVD) method. The promising high power rate anode material GeNWs grown on the surface of GNF bundle to mutually form entangled structure. contact area between GNFs enabled electrons be efficiently transported entwined with minimized degradation electrochemical characteristics. These...
Vertically aligned ZnO nanorod arrays were directly grown on flexible and transparent oxidized bi-layer graphene electrodes by seedless electrochemical deposition. Oxidized defects the surface induce epitaxial growth of highly dense single crystal nanorods. The diameter, length as well morphology nanorods can be effectively controlled adjusting reaction conditions.