214 citations · 620 across the 19 of their papers we have counts for
19 papers
Ab Initio Thermodynamic Study of PbI and CHNHPbI Surfaces in Reaction with CHNH Gas for Perovskite Solar Cells
Yun-Sim Kim, Chol-Hyok Ri, Yun-Hyok Kye +2
Hybrid organic-inorganic halide perovskites for photovoltaics have attracted research interest due to their unique material properties, but suffered from poor material stability. I…
Contrary Effect of B and N Doping into Graphene and Graphene Oxide Heterostructures with MoS on Interface Function and Hydrogen Evolution
Chol-Hyok Ri, Yun-Sim Kim, Kum-Chol Ri +2
Molybdenum disulfide (MoS) attracts attention as a high efficient and low cost photocatalyst for hydrogen production, but suffers from low conductance and high recombination ra…
Influence of M/A substitution on material properties of intermetallic compounds MSn (M = Fe, Co; A = Li, Na): A first-principles study
Chol-Jun Yu, Un-Song Hwang, Yong-Chol Pak +4
Iron and cobalt distannides \ce{MSn2} (M = Fe, Co) are regarded as a promising conversion-type anode material for lithium- and sodium-ion batteries, but their properties are not we…
Manifestation of the thermoelectric properties in Ge-based halide perovskites
Un-Gi Jong, Chol-Jun Yu, Yun-Hyok Kye +2
In spite of intensive studies on the chalcogenides as conventional thermoelectrics, it remains a challenge to find a proper material with high electrical but low thermal conductivi…
First-Principles Study on Material Properties and Stability of Inorganic Halide Perovskite Solid Solutions CsPb(IBr) towards High Performance Perovskite Solar Cells
Chol-Jun Yu, Un-Hyok Ko, Suk-Gyong Hwang +4
All-inorganic halide perovskites have attracted a great interest as a promising light harvester of perovskite solar cells due to their enhanced chemical stability. In this work we…
Computational Prediction of Structural, Electronic, Optical Properties and Phase Stability of Double Perovskites K2SnX6 (X = I, Br, Cl)
Un-Gi Jong, Chol-Jun Yu, Yun-Hyok Kye
Vacancy-ordered double perovskites K2SnX6 (X = I, Br, Cl) attract significant research interest due to their potential application as light-absorbing materials in perovskite solar…
Defect physics in -doped from first-principles calculation
Yun-Hyok Kye, Chol-Jun Yu, Un-Gi Jong +2
Calcium fluoride has been widely used for light up-/down-conversion luminescence by accommodating lanthanide ions as sensitizers or activators. Especially, Yb-doped \ce{CaF2} exhib…
Interface Engineering in Hybrid Iodide CH3NH3PbI3 Perovskite Using Lewis Base and Graphene towards High Performance Solar Cells
Chol-Jun Yu, Yun-Hyok Kye, Un-Gi Jong +6
Perovskite solar cells have achieved a substantial breakthrough via advanced interface engineerings. Reports have emphasized that combining the hybrid perovskites with Lewis base a…
First-Principles Study on NaxTiO2 with Trigonal Bipyramid Structures: An Insight into Sodium-Ion Battery Anode Application
Song-Hyok Choe, Chol-Jun Yu, Kum-Chol Ri +4
Developing efficient anode materials with low electrode voltage, high specific capacity and superior rate capability is urgently required on the road to commercially viable sodium-…
First-principles study on the chemical decomposition of inorganic perovskites \ce{CsPbI3} and \ce{RbPbI3} at finite temperature and pressure
Un-Gi Jong, Chol-Jun Yu, Yun-Hyok Kye +3
Inorganic halide perovskite \ce{Cs(Rb)PbI3} has attracted significant research interest in the application of light-absorbing material of perovskite solar cells (PSCs). Although th…
The maximum interbubble distance in relation to the radius of spherical stable nanobubble in liquid water: A molecular dynamics study
Song-Nam Hong, Song-Hyok Choe, Un-Gi Jong +2
The mechanism of superstability of nanobubbles in liquid confirmed by many experimental studies is still in debate since the classical diffusion predicts their lifetime on the orde…
First-principles study on the electronic and optical properties of inorganic perovskite Rb1-xCsxPbI3 for solar cell applications
Un-Gi Jong, Chol-Jun Yu, Yun-Sim Kim +2
Recently, replacing or mixing organic molecules in the hybrid halide perovskites with the inorganic Cs or Rb cations has been reported to increase the material stability with the c…
Critical role of water in defect aggregation and chemical degradation of perovskite solar cells
Yun-Hyok Kye, Chol-Jun Yu, Un-Gi Jong +2
The chemical stability of methylammonium lead iodide (\ce{MAPbI3}) under humid conditions remains the primary challenge facing halide perovskite solar cells. We investigate defect…
Revealing the stability and efficiency enhancement in mixed halide perovskites MAPb(ICl) with ab initio calculations
Un-Gi Jong, Chol-Jun Yu, Yong-Man Jang +3
A little addition of Cl to \ce{MAPbI3} has been reported to improve the material stability as well as light harvesting and carrier conducting properties of organometal trihalide pe…
Ab initio thermodynamic study of SnO(110) surface in an O and NO environment: a fundamental understanding of gas sensing mechanism for NO and NO
Chol-Jun Yu, Yun-Hyok Kye, Song-Nam Hong +5
For the purpose of elucidating the gas sensing mechanism of SnO for NO and NO gases, we calculate the phase diagram of SnO(110) surface in contact with an O and NO…
Influence of halide composition on the structural, electronic, and optical properties of mixed CHNHPb(IBr) perovskites calculated using the virtual crystal approximation method
Un-Gi Jong, Chol-Jun Yu, Nam-Hyok Kim +1
We investigate the structural, electronic and optical properties of mixed bromide-iodide lead perovskite solar cell CHNHPb(IBr) by means of the virtual crys…
First-principles study of ferroelectricity induced by p-d hybridization in ferrimagnetic NiFe2O4
Un-Gi Jong, Chol-Jun Yu, Yong-Su Park +1
We investigate the ferrimagnetism and ferroelectricity of bulk NiFeO with tetragonal ~symmetry by means of density functional calculations using generalized gradie…
First-principles study of ternary graphite compounds cointercalated with alkali atoms (Li, Na, and K) and alkylamines towards alkali ion battery applications
Gum-Chol Ri, Chol-Jun Yu, Jin-Song Kim +3
Using density functional theory calculations, we have investigated the structural, energetic, and electronic properties of ternary graphite intercalation compounds (GICs) containin…
Electronic structure and photo absorption property of pseudo-cubic perovskites CHNHPbX (X=I, Br) including van der Waals interaction
Chol-Jun Yu, Un-Gi Jong, Mun-Hyok Ri +1
Using density functional theory with the inclusion of van der Waals (vdW) interaction, we have investigated electronic energy bands, density of states, effective masses of charge c…