Browsing Cho, Kyeongjae by Issue Date
Now showing items 1-19 of 19
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In Situ Study of the Role of Substrate Temperature during Atomic Layer Deposition of HfO2 on InP
(2013-10-16)The dependence of the "self cleaning" effect of the substrate oxides on substrate temperature during atomic layer deposition (ALD) of HfO₂ on various chemically treated and native oxide InP (100) substrates is investigated ... -
Selectivity of Metal Oxide Atomic Layer Deposition on Hydrogen Terminated and Oxidized Si(001)-(2x1) Surface
(A V S Amer Inst Physics, 2014-02-10)In this work, the authors used density-functional theory methods and x-ray photoelectron spectroscopy to study the chemical composition and growth rate of HfO₂, Al₂O₃, and TiO₂ thin films grown by in-situ atomic layer ... -
Tunable H₂ Binding on Alkaline and Alkaline Earth Metals Decorated Graphene Substrates from First-Principles Calculations
(Pergamon-Elsevier Science Ltd, 2017-04-13)Based on first-principles calculations, the H-2 adsorptions onto six types of modified graphene substrates decorated with light metals (Li, Na, K, Be, Mg, Ca) are investigated to shed light on the factors affecting the H-2 ... -
Nucleation and Growth of WSe₂: Enabling Large Grain Transition Metal Dichalcogenides
(IOP Publishing Ltd, 2017-09-22)The limited grain size (< 200 nm) for transition metal dichalcogenides (TMDs) grown by molecular beam epitaxy (MBE) reported in the literature thus far is unsuitable for high-performance device applications. In this work, ... -
Investigation of the Hydrothermal Aging of an Mn-Based Mullite SmMn₂O₅ Catalyst of NO Oxidation
(Royal Society of Chemistry, 2017-10-20)Hydrothermal aging tests are important to carry out when evaluating the hydrothermal durability of heterogeneous catalysts in vehicle exhaust emission. Here, we explored the effect of aging on an efficient Mn-based mullite ... -
A Kinetic Monte Carlo Simulation Method of Van Der Waals Epitaxy for Atomistic Nucleation-Growth Processes of Transition Metal Dichalcogenides
(Nature Publishing Group, 2018-08-31)Controlled growth of crystalline solids is critical for device applications, and atomistic modeling methods have been developed for bulk crystalline solids. Kinetic Monte Carlo (KMC) simulation method provides detailed ... -
In Situ Study of E-Beam Al And Hf Metal Deposition on Native Oxide InP (100)
The interfacial chemistry of thin Al (∼3 nm) and Hf (∼2 nm) metal films deposited by electron beam (e-beam) evaporation on native oxide InP (100) samples at room temperature and after annealing has been studied by in situ ... -
Phase Stability of Li-Mn-O Oxides as Cathode Materials for Li-ion Batteries: Insights from ab initio Calculations
In this work, we present a density-functional theory (DFT) investigation of the phase stability, electrochemical stability and phase transformation mechanisms of the layered and over-lithiated Mn oxides. This study includes ... -
α-MnO₂ Nanowire Catalysts with Ultra-High Capacity and Extremely Low Overpotential in Lithium-Air Batteries through Tailored Surface Arrangement
We here report on very high capacity (11000 mA h g⁻¹), superb rate capability (4500 mA h g⁻¹ at 5000 mA g⁻¹) and high reversibility of Li-air batteries using α-MnO₂ NW catalysts mainly associated with their relatively large ... -
Modulation of Contact Resistance between Metal and Graphene by Controlling the Graphene Edge, Contact Area, and Point Defects: An Ab Initio Study
A systematic first-principles non-equilibrium Green's function study is conducted on the contact resistance between a series of metals (Au, Ag, Pt, Cu, Ni, and Pd) and graphene in the side contact geometry. Different factors ... -
MoS₂ Functionalization for Ultra-Thin Atomic Layer Deposited Dielectrics
The effect of room temperature ultraviolet-ozone (UV-O₃) exposure of MoS₂ on the uniformity of subsequent atomic layer deposition of Al₂O₃ is investigated. It is found that a UV-O₃ pre-treatment removes adsorbed carbon ... -
Electrode-Electrolyte Interface for Solid State Li-Ion Batteries: Point Defects and Mechanical Strain
In this work, we present an ab-initio investigation of point defects in solid electrolyte γ-Li₃PO₄ and in negative electrode-electrolyte interface (Li/γ-Li₃PO₄). Our results on Li defects on γ-Li₃PO₄ exhibit that Li ... -
Multicomponent Silicate Cathode Materials for Rechargeable Li-ion Batteries: An Ab Initio Study
A first principles investigation is performed to study the structural and electrochemical properties of new multicomponent silicate materials that can be suitable for the cathode of rechargeable Li-ion batteries. The ... -
Spurious Dangling Bond Formation During Atomically Precise Hydrogen Depassivation Lithography on Si(100): The Role of Liberated Hydrogen
The production of spurious dangling bonds during the hydrogen depassivation lithography process on Si(100)-H is studied. It is shown that the number of spurious dangling bonds produced depends on the size of the primary ... -
Organic-Inorganic Hybrid Semiconductor Thin Films Deposited Using Molecular-Atomic Layer Deposition (MALD)
Molecular-atomic layer deposition (MALD) is employed to fabricate hydroquinone (HQ)/diethyl zinc (DEZ) organic-inorganic hybrid semiconductor thin films with accurate thickness control, sharp interfaces, and low deposition ... -
Underlying Mechanisms of the Synergistic Role of Li₂MnO₃ and LiNi_{1/3}Co_{1/3}Mn_{1/3}O₂ in High-Mn, Li-Rich Oxides
For large-scale energy storage applications requiring high energy density, the development of Li-rich oxides with enhanced cyclic stabilities during high-voltage operations and large specific capacities is required. In ... -
Tuning Electronic Transport in Epitaxial Graphene-Based Van Der Waals Heterostructures
Two-dimensional tungsten diselenide (WSe₂) has been used as a component in atomically thin photovoltaic devices, field effect transistors, and tunneling diodes in tandem with graphene. In some applications it is necessary ... -
Enhanced P-Type Behavior in 2D WSe2 via Chemical Defect Engineering
Defect engineering of 2D semiconducting transition metal dichalcogenides (TMDCs) has been demonstrated to be a promising way to tune both their bandgaps and carrier concentrations. Moreover, controlled introduction of ... -
Quantum Transport and Band Structure Evolution under High Magnetic Field in Few-Layer Tellurene
Quantum Hall effect (QHE) is a macroscopic manifestation of quantized states that only occurs in confined two-dimensional electron gas (2DEG) systems. Experimentally, QHE is hosted in high-mobility 2DEG with large external ...