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Your search keyword '"Jeong, Hu Young"' showing total 523 results
Start Over Author "Jeong, Hu Young" Publication Type Academic Journals
523 results on '"Jeong, Hu Young"'

2. Area-selective atomic layer deposition on 2D monolayer lateral superlattices

Author

Park, Jeongwon, Kwak, Seung Jae, Kang, Sumin, Oh, Saeyoung, Shin, Bongki, Noh, Gichang, Kim, Tae Soo, Kim, Changhwan, Park, Hyeonbin, Oh, Seung Hoon, Kang, Woojin, Hur, Namwook, Chai, Hyun-Jun, Kang, Minsoo, Kwon, Seongdae, Lee, Jaehyun, Lee, Yongjoon, Moon, Eoram, Shi, Chuqiao, Lou, Jun, Lee, Won Bo, Kwak, Joon Young, Yang, Heejun, Chung, Taek-Mo, Eom, Taeyong, Suh, Joonki, Han, Yimo, Jeong, Hu Young, Kim, YongJoo, and Kang, Kibum

Published
2024
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3. Zn-Ion Transporting, In Situ Formed Robust Solid Electrolyte Interphase for Stable Zinc Metal Anodes over a Wide Temperature Range

Author

Xiong, Peixun, Kang, Yingbo, Yao, Nan, Chen, Xiang, Mao, Haiyan, Jang, Woo-Sung, Halat, David M, Fu, Zhong-Heng, Jung, Min-Hyoung, Jeong, Hu Young, Kim, Young-Min, Reimer, Jeffrey A, Zhang, Qiang, and Park, Ho Seok

Subjects
Engineering, Materials Engineering, Chemical Sciences, Physical Chemistry, Affordable and Clean Energy, Chemical sciences
Abstract

Hydrogen evolution, corrosion, and dendrite formation in the Zn anodes limit their practical applications in aqueous Zn metal batteries. Herein, we propose an interfacial chemistry regulation strategy that uses hybrid electrolytes of water and a polar aprotic N,N-dimethylformamide to modify the Zn2+-solvation structure and in situ form a robust and Zn2+-conducting Zn5(CO3)2(OH)6 solid electrolyte interphase (SEI) on the Zn surface to achieve stable and dendrite-free Zn plating/stripping over a wide temperature range. As confirmed by 67Zn nuclear magnetic resonance relaxometry, electrochemical characterizations, and molecular dynamics simulation, the electrochemically and thermally stable Zn5(OH)6(CO3)2-contained SEI achieved a high ionic conductivity of 0.04 to 1.27 mS cm-1 from −30 to 70 °C and a thermally activated fast Zn2+ migration through the [010] plane. Consequently, extremely stable Zn-ion hybrid capacitors in hybrid electrolytes are demonstrated with high capacity retentions and Coulombic efficiencies over 14,000, 10,000, and 600 cycles at 25, −20, and 70 °C, respectively.

Published
2023

13. Abrading bulk metal into single atoms

Author

Han, Gao-Feng, Li, Feng, Rykov, Alexandre I., Im, Yoon-Kwang, Yu, Soo-Young, Jeon, Jong-Pil, Kim, Seok-Jin, Zhou, Wenhui, Ge, Rile, Ao, Zhimin, Shin, Tae Joo, Wang, Junhu, Jeong, Hu Young, and Baek, Jong-Beom

Published
2022
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17. Insight on Strain Relaxation Effect in Perovskites for High‐Temperature Hydrogen Oxidation Reaction.

Author

Kim, Hyunmin, Lim, Chaesung, Gu, Jiamin, Jeong, Hu Young, Han, Jeong Woo, Jang, Ji‐Hyun, and Bu, Yunfei

Subjects
CHEMICAL kinetics, HYDROGEN oxidation, OXIDATION kinetics, NANOPARTICLE size, DENSITY functional theory
Abstract

The size of in situ exsolved nanoparticles (NPs) significantly affects the electrochemical and electro‐catalytic properties of oxide supports. Unfortunately, the instrumental factor affecting the exsolved NP size in poly‐crystalline perovskite oxides is still unexplored. Herein, the inherent micro‐strain (ε) value as an unprecedented factor in controlling the exsolved NP size of Pr0.5Ba0.5‐xSrxFe0.85Ni0.15O3‐δ (x = 0.3, 0.4, and 0.5) is introduced, wherein smaller NP size is successfully obtained via strain relaxation strategy. The effect of exsolved NP size on the fuel oxidation reaction kinetics at high‐temperature regimes is evaluated in‐depth by using density functional theory (DFT) calculations. In accordance with the insights provided by DFT calculations, the electro‐catalyst featuring the smallest Fe3Ni NP size via strain relaxation strategy demonstrates exceptional electrochemical performance along with robust durability toward high‐temperature hydrogen oxidation reaction. This work presents scientific guidance for tailoring the exsolved NP size in perovskites, thereby paving the way for designing rational perovskite electro‐catalysts in various energy‐related applications. [ABSTRACT FROM AUTHOR]

Published
2024
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18. Enhanced Long‐Term Stability of Crystalline Nickel–Boride (Ni23B6) Electrocatalyst by Encapsulation with Hexagonal Boron Nitride.

Author

Ma, Kyung Yeol, Kim, Hyeongjoon, Hwang, Hyuntae, Jeong, Da Sol, Lee, Hoon Ju, Cho, Kyeongseo, Yang, Jieun, Jeong, Hu Young, and Shin, Hyeon Suk

Subjects
HYDROGEN evolution reactions, NICKEL catalysts, CHEMICAL structure, SURFACE morphology, CATALYSTS
Abstract

Nickel boride catalysts show great potential as low‐cost and efficient alternatives to noble‐metal catalysts in acidic media; however, synthesizing and isolating a specific phase and composition of nickel boride is nontrivial, and issues persist in their long‐term stability as electrocatalysts. Here, a single‐crystal nickel boride, Ni23B6, is reported which exhibits high electrocatalytic activity for the hydrogen evolution reaction (HER) in an acidic solution, and that its poor long‐term stability can be overcome via encapsulation by single‐crystal trilayer hexagonal boron nitride (hBN) film. Interestingly, hBN‐covered Ni23B6 on a Ni substrate shows an identical overpotential of 52 mV at a current density of 10 mA cm−2 to that of bare Ni23B6. This phenomenon indicates that the single‐crystalline hBN layer is catalytically transparent and does not obstruct HER activation. The hBN/Ni23B6/Ni has remarkable long‐term stability with negligible changes to its polarization curves for 2000 cycles, whereas the Ni23B6/Ni shows significant degradation after 650 cycles. Furthermore, chronoamperometric measurements indicate that stability is preserved for >20 h. Long‐term stability tests also reveal that the surface morphology and chemical structure of the hBN/Ni23B6/Ni electrode remain preserved. This work provides a model for the practical design of robust and durable electrochemical catalysts through the use of hBN encapsulation. [ABSTRACT FROM AUTHOR]

Published
2024
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25. Boltzmann Switching MoS2 Metal–Semiconductor Field‐Effect Transistors Enabled by Monolithic‐Oxide‐Gapped Metal Gates at the Schottky–Mott Limit.

Author

Kim, Yeon Ho, Jiang, Wei, Lee, Donghun, Moon, Donghoon, Choi, Hyun‐Young, Shin, June‐Chul, Jeong, Yeonsu, Kim, Jong Chan, Lee, Jaeho, Huh, Woong, Han, Chang Yong, So, Jae‐Pil, Kim, Tae Soo, Kim, Seong Been, Koo, Hyun Cheol, Wang, Gunuk, Kang, Kibum, Park, Hong‐Gyu, Jeong, Hu Young, and Im, Seongil

Published
2024
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26. Direct observation of twisted stacking domains in the van der Waals magnet CrI3.

Author

Jang, Myeongjin, Lee, Sol, Cantos-Prieto, Fernando, Košić, Ivona, Li, Yue, McCray, Arthur R. C., Jung, Min-Hyoung, Yoon, Jun-Yeong, Boddapati, Loukya, Deepak, Francis Leonard, Jeong, Hu Young, Phatak, Charudatta M., Santos, Elton J. G., Navarro-Moratalla, Efrén, and Kim, Kwanpyo

Subjects
MAGNETIC coupling, PROPERTIES of matter, CONDENSED matter, PHASE transitions, MAGNETIC materials, MAGNETS
Abstract

Van der Waals (vdW) stacking is a powerful technique to achieve desired properties in condensed matter systems through layer-by-layer crystal engineering. A remarkable example is the control over the twist angle between artificially-stacked vdW crystals, enabling the realization of unconventional phenomena in moiré structures ranging from superconductivity to strongly correlated magnetism. Here, we report the appearance of unusual 120° twisted faults in vdW magnet CrI3 crystals. In exfoliated samples, we observe vertical twisted domains with a thickness below 10 nm. The size and distribution of twisted domains strongly depend on the sample preparation methods, with as-synthesized unexfoliated samples showing tenfold thicker domains than exfoliated samples. Cooling induces changes in the relative populations among different twisting domains, rather than the previously assumed structural phase transition to the rhombohedral stacking. The stacking disorder induced by sample fabrication processes may explain the unresolved thickness-dependent magnetic coupling observed in CrI3. Artificial stacking of van der Waals materials is an effective method to design and investigate emergent physical properties in condensed matter systems. Here, the authors characterize the natural twisted layer structure of CrI3, showing its dependence on the sample fabrication process and its implications for the magnetic properties of the material. [ABSTRACT FROM AUTHOR]

Published
2024
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29. Different power perceptions based on socially situated needs: Findings from a qualitative study among Asian Americans.

Author

Jeong, Hu Young, Vollhardt, Johanna Ray, Twali, Michelle S., and Tawa, John

Subjects
*ASIAN Americans, *QUALITATIVE research, *INGROUPS (Social groups), *THEMATIC analysis, *MINORITIES, *RACIAL minorities
Abstract

While power is often defined and operationalized as control or influence over others, alternative conceptualizations define power as the ability to meet various fundamental needs. We argue that this conceptualization may better capture how marginalized minority group members understand their group's power or powerlessness. However, there is little research examining how people themselves construe group‐based power. The present study, therefore, used qualitative inquiry to examine perceived ingroup power among Asian Americans, an underrepresented racial minority group with an ambivalent power status in society. Reflexive thematic analysis of 25 interviews illustrated the relevance of Prilleltensky's (J. Community Psychol., 36, 2008, 116) psychopolitical conceptualization of power. Specifically, we identified eight themes that reflect various context‐specific construals of power as oppression, wellness and liberation. Additionally, the findings suggest the need to consider intragroup heterogeneity in power and to situate how power is understood in the given sociopolitical, structural context. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Graphene‐Based Lateral Heterojunctions for 2D Integrated Circuits.

Author

Haidari, Mohd.Musaib, Jang, Dong Jin, Yoon, Duhee, Kim, Hakseong, Choi, Hong Kyw, Yi, Yoonsik, Kim, Jin Hong, Ko, Jin‐Yong, Lee, Dooho, Kee, Eun Hee, Jeong, Hu Young, Park, Jeong Young, Park, Bae Ho, and Choi, Jin Sik

Subjects
INTEGRATED circuits, SCANNING probe microscopy, HETEROJUNCTIONS, ELECTRONIC equipment, ELECTRIC conductivity, GRAPHENE synthesis
Abstract

A method for patterning single‐layer graphene (SLG) and single‐layer oxidized graphene (SOG) within a continuous atomic layer to form lateral heterojunctions is presented. Raman spectroscopy is employed to investigate the evolution of defect‐related Raman peaks during excimer‐UV irradiation, facilitating the identification of structural changes and defect formation processes. Electrical transport measurements reveal that SOG‐patterned field‐effect transistors (FETs) exhibit varying characteristics depending on the degree of oxidation, thus offering the potential to tailor the electrical properties of graphene devices for specific requirements. Scanning Kelvin probe microscopy measurements reveal the surface potential and work function of the SOG regions compared with those of SLG. The effective functionality of the SOG pattern to operate as a resistor, allowing control of the electrical conductivity in the SOG‐patterned SLG channels, is demonstrated. This capability restricts the current flow while preserving the pristine electrical properties of the graphene channel. Moreover, the SOG pattern can serve as a potential barrier to constructing SLG‐SOG‐patterned integrated circuits, providing exciting opportunities for engineering advanced electronic components. This breakthrough in graphene devices simplifies the fabrication process of graphene‐based FETs and provides the foundation for developing atomically thin integrated circuits for a wide range of applications. [ABSTRACT FROM AUTHOR]

Published
2024
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36. Facile fabrication of properties-controllable graphene sheet.

Author

Choi, Jin Sik, Choi, Hongkyw, Kim, Ki-Chul, Jeong, Hu Young, Yu, Young-Jun, Kim, Jin Tae, Kim, Jin-Soo, Shin, Jin-Wook, Cho, Hyunsu, and Choi, Choon-Gi

Abstract

Graphene has been received a considerable amount of attention as a transparent conducting electrode (TCE) which may be able to replace indium tin oxide (ITO) to overcome the significant weakness of the poor flexibility of ITO. Given that graphene is the thinnest 2-dimensional (2D) material known, it shows extremely high flexibility, and its lateral periodic honeycomb structure of sp(2)-bonded carbon atoms enables ~2.3% of incident light absorption per layer. However, there is a trade-off between the electrical resistance and the optical transmittance, and the fixed absorption rate in graphene limits is use when fabricating devices. Therefore, a more efficient method which continuously controls the optical and electrical properties of graphene is needed. Here, we introduce a method which controls the optical transmittance and the electrical resistance of graphene through various thicknesses of the top Cu layers with a Cu/Ni metal catalyst structure used to fabricate a planar mesh pattern of single and multi-layer graphene. We exhibit a continuous transmittance change from 85% (MLG) to 97.6% (SLG) at an incident light wavelength of 550 nm on graphene samples simultaneously grown in a CVD quartz tube. We also investigate the relationships between the sheet resistances.

Published
2016

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