Article
Nanoscience & Nanotechnology
Eui Young Jung, Jeongil Bang, Ji Hyeon Hwang, Dong Hee Han, Youngjin Kim, Haeryong Kim, Woojin Jeon
Summary: The research investigated the chemical properties of Ru for electrode application and its degradation mechanism, revealing that appropriate pretreatment can ameliorate Ru degradation and result in excellent electrical properties.
Article
Engineering, Electrical & Electronic
Dae Seon Kwon, Tae Kyun Kim, Junil Lim, Haengha Seo, Heewon Paik, Cheol Seong Hwang
Summary: The physicochemical and electrical properties of Pt/Al-doped TiO2 (ATO)/Ru/TiN capacitors were investigated by adding an atomic-layer-deposited Ru interlayer between the ATO and the TiN layers. The thickness of the Ru interlayer played a crucial role in improving the electrical performance of the capacitors.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Physics, Multidisciplinary
V Maurya, G. Sharma, K. B. Joshi
Summary: Density functional theory at various levels is used to study the structural and electronic properties of RuO2 crystals, revealing pressure-induced phase transitions and metal-insulator transitions accompanied by orbital ordering. The calculations show that the rutile and pyrite crystals are metals, while the hypothetical fluorite crystal is a semiconductor with an indirect bandgap in the range of 0.57-2.96 eV. The Fermi surface calculations using GGA + U show improvement over GGA.
Article
Chemistry, Physical
Prangya P. Sahoo, Miroslav Mikolasek, Kristina Husekova, Edmund Dobrocka, Jan Soltys, Peter Ondrejka, Martin Kemeny, Ladislav Harmatha, Matej Micusik, Karol Frohlich
Summary: This study investigated the properties of metal-insulator-semiconductor (MIS) photoanodes with RuO2/SiO2/n-Si and IrO2-RuO2/SiO2/n-Si configurations for water oxidation. The results showed that both structures exhibited better oxygen evolution performance under acidic conditions compared to alkaline or near-neutral pH conditions.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Jongin Cha, Jangyup Son, Jongill Hong
Summary: This study investigates the impact of bottom-electrode contact on graphene devices and demonstrates the ability to achieve extremely low contact resistivity. The enhanced density of states (DOS) at the bottom-electrode contact is the key factor for achieving low resistivity.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Physical
Lin Ma, Borong Lu, Shaobin Li, Jingwei Liang, Li Zhang, Minjie Liang, Mingrui Pang
Summary: Two novel 2D POMOF crystalline materials were synthesized and the relationship between their structure and catalytic performance was investigated. Compound 1 exhibited better electrochemical performance, with a specific capacitance of 407.7 F g-1 at 3 A g-1 and 89.5% cycling stability after 1000 cycles at a current density of 10 A g-1.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Engineering, Electrical & Electronic
Hsin-Jyun Lin, Chihiro Tamura, Koji Akiyama, Genji Nakamura, Hiroyuki Nagai, Hiroshi Watanabe
Summary: A method is proposed for analyzing the dielectric prebreakdown (DB) in a metal-insulator-metal (MIM) stacked polycrystalline high-k capacitor of TiN-TiO2-ZrO2-TiO2-TiN based on charge transport, stochastic trap-cluster generation, and percolation. The measured dielectric leakage current until breakdown is assumed to be comprised of transient transports under static fields such as direct tunneling, trap-assisted tunneling (TAT), and inelastic tunneling. The generated trap-cluster amplifies the stress-induced leakage current (SILC) and can form a critical path by electrically linking the cathode and anode throughout the dielectric. Prebreakdown is found to be most related to SILC and inelastic tunneling at a low electric field (<4 MV/cm) through careful analysis of the measured time-dependent dielectric leakage currents.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Physics, Applied
HoHyun Im, Geonyeop Lee, Hyunik Park, Dongryul Lee, Jihyun Kim
Summary: In this study, a Pt/hBN/WSe2 low-dimensional capacitor was fabricated, and a WOX layer was formed through UV/ozone treatment. The capacitance-voltage (C-V) behavior exhibited ambipolar transport characteristics in the pristine condition, and a typical p-type behavior after p-doping. The controllability of the charge-transfer doping method was confirmed through analysis of different doping concentrations.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
A. M. Mumlyakov, M. Shibalov, E. R. Timofeeva, I. Trofimov, N. Porokhov, S. A. Evlashin, P. A. Nekludova, E. A. Pershina, Yu Anufriev, A. M. Tagachenkov, E. Zenova, M. A. Tarkhov
Summary: This research demonstrates the fabrication technology of three-dimensional capacitors based on carbon nanostructure, showing that the carbon nanostructure can significantly increase the capacitance density of capacitors and allow for mass production. The study includes a comparative analysis of capacitors with and without carbon nanostructure, revealing the potential of using carbon nanostructure in the development of high-performance capacitors.
Article
Engineering, Electrical & Electronic
Yunsang Shin, Seung Geol Nam, Jinseong Heo, Sangwook Nam
Summary: This study proposes a new nonresonant method for accurately extracting the properties of thin dielectric by measuring the reflection coefficient of metal-insulator-metal (MIM) capacitors. The method is validated through equivalent circuit modeling and 3-D full-wave electromagnetic simulations. The experimental results demonstrate that the proposed method achieves high-accuracy characterization of the complex permittivity and loss tangent of high-k dielectrics in a broadband frequency range.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Materials Science, Multidisciplinary
Sarajit Biswas
Summary: The electronic and magnetic properties of rutile ruthenium dioxide (RuO2) change significantly under different on-site Coulomb interaction U, transitioning from nonmagnetic metal to ferromagnetic metal and then to half-metallic ferromagnetic phase across various U values. Magnetism in RuO2 is influenced by the strong dynamical electron correlation, leading to metal-insulator transition at higher U values.
Article
Engineering, Electrical & Electronic
Chinsung Park, Harshil Kashyap, Dipjyoti Das, Jae Hur, Nujhat Tasneem, Sarah Lombardo, Nashrah Afroze, Winston Chern, Andrew C. Kummel, Shimeng Yu, Asif Islam Khan
Summary: Strategies to reduce the interfacial oxide layer thickness in ferroelectric Hf0.5Zr0.5O2 (HZO) metal-oxide-semiconductor capacitors on Ge and Si substrates were investigated. Changing the gate metal from W to Pt/Ti in Ge capacitors resulted in a 66% reduction of the coercive voltage and a 64% increase in capacitance, indicating interfacial layer thinning. High-resolution scanning transmission electron microscopy (HR-STEM) showed no visible interfacial layer with Pt/Ti electrodes in Ge capacitors, suggesting oxygen scavenging. However, a smaller reduction of the coercive voltage was observed in Si capacitors with Pt/Ti electrodes.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Physical
Min Jong Lee, Muhammad Ahsan Saeed, Tae Hyuk Kim, Jae Jin Chung, Jae Won Shim
Summary: Despite challenges faced by transparent conductive electrodes in energy storage and conversion devices, the use of In2O3:V2O5 nanocompound materials shows promise in improving the performance of organic photovoltaics and metal-insulator-metal capacitors.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Jae Jin Chung, Tae Hyuk Kim, Muhammad Ahsan Saeed, Jae Won Shim
Summary: Research on transparent conductive oxides (TCOs) has made significant progress, but limitations in work function, charge mobility, and surface roughness hinder their use in optoelectronic devices. This study used atomic layer deposition (ALD) to fabricate In2O3:MoOX nanolaminates, which exhibited low resistivity and high transmittance in the near-infrared region. The nanolaminates showed high mobility and work function, making them suitable for organic photovoltaics (OPVs) and metal-insulator-metal (MIM) capacitors. The performance of In2O3:MoOX nanolaminates in OPVs eliminated the need for a hole-transport layer, while in MIM capacitors, they demonstrated high capacitance and low leakage current.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Coatings & Films
Kunio Okimura, Joe Sakai, Masashi Kuwahara, Mustapha Zaghrioui, Yoichi Uehara
Summary: Ultrathin VO2 films exhibiting insulator-metal transition were successfully fabricated on sapphire substrates using radio frequency-biased reactive sputtering. A 6nm-thick VO2 film showed significant resistance change over 2 orders of magnitude. Films with thickness up to around 10nm displayed characteristic networking morphology. Additionally, a 30nm-thick film demonstrated a flat surface, ordered lattice, and strong in-plane tensile stress.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2021)
Article
Nanoscience & Nanotechnology
Jung Joon Pyeon, In-Hwan Baek, Woo Chul Lee, Hansol Lee, Sung Ok Won, Ga-Yeon Lee, Taek-Mo Chung, Jeong Hwan Han, Seung-Hyub Baek, Jin-Sang Kim, Ji-Won Choi, Chong-Yun Kang, Seong Keun Kim
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Materials Science, Ceramics
Sang-Soon Lim, Sung-Jin Jung, Byung Kyu Kim, Dong-Ik Kim, Byeong-Hyeon Lee, Sung Ok Won, Joonchul Shin, Hyung-Ho Park, Seong Keun Kim, Jin-Sang Kim, Seung-Hyub Baek
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2020)
Article
Materials Science, Coatings & Films
Hong Keun Chung, Jung Joon Pyeon, In-Hwan Baek, Ga-Yeon Lee, Hansol Lee, Sung Ok Won, Jeong Hwan Han, Taek-Mo Chung, Tae Joo Park, Seong Keun Kim
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2020)
Article
Chemistry, Physical
Haena Yim, So Yeon Yoo, Yeon Ho Kim, Keun Hwa Chae, Yong-Hoon Kim, Seong Keun Kim, Seung-Hyub Baek, Chul-Ho Lee, Ji-Won Choi
Summary: This study presents a general strategy for obtaining large-area, defect-controlled high-k dielectric films using scalable layer-by-layer assembly of single-crystalline perovskite oxide nanosheets, which are suitable for all-2D field-effect transistors. By utilizing a layer-by-layer assembly process, multilayered Sr1.8Bi0.2Nb3O10 nanosheet films with high uniformity and low defects were successfully fabricated.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Physical
Young Geun Song, In-Hwan Baek, Jae-Gyun Yim, Taeyong Eom, Taek-Mo Chung, Chul-Ho Lee, Cheol Seong Hwang, Chong-Yun Kang, Seong Keun Kim
Summary: This study presents a highly sensitive NO2 gas sensor composed of cross-linked p-type SnS nanoplates on SiO2 nanorods, with area-selective growth of SnS by atomic layer deposition allowing for enhanced gas response of p-type semiconductor sensors without the need for additional patterning.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Editorial Material
Engineering, Electrical & Electronic
Seong Keun Kim
NATURE ELECTRONICS
(2022)
Article
Nanoscience & Nanotechnology
Nahid Sultan Al-Mamun, Douglas E. Wolfe, Aman Haque, Jae-Gyun Yim, Seong Keun Kim
Summary: A room temperature annealing method using electron impulse force is demonstrated to significantly improve the crystallinity and reduce the resistivity of tin disulfide, which is important for post-synthesis annealing applications that require high temperature and special environments.
SCRIPTA MATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Jaegyun Yim, Hong Keun Chung, Seung Ho Ryu, Han Kim, Sung Ok Won, Taeyong Eom, Taek-Mo Chung, Seong Keun Kim
Summary: This study demonstrates the area-selective atomic layer deposition (ALD) of SnS2 on SiO2 and Al2O3 surfaces. By optimizing the super-cycle conditions, selective SnS2 deposition of approximately 7 nm thickness was achieved on both SiO2 and Al2O3. This method contributes to the improvement of area-selective deposition technology for BEOL-compatible transistors.
ACS APPLIED NANO MATERIALS
(2023)
Article
Physics, Applied
Jihoon Jeon, Song-Hyeon Kuk, Ah-Jin Cho, Seung-Hyub Baek, Sang-Hyeon Kim, Seong Keun Kim
Summary: We have fabricated n-type ferroelectric field-effect transistors (FeFETs) using atomic-layer-deposited HfZrOx (HZO) films with a large memory window (MW) immediately after the write operation. Charge trapping at the HZO/Si interface in FeFETs is identified as the main cause of memory window reduction. By controlling the properties of the interfacial layer through varying the O-3 injection time during atomic layer deposition, the FeFETs based on HZO (long O-3 of 7 s) exhibit a larger MW (2.1 V) compared to the FeFETs based on HZO (short O-3 of 0.3 s) (0.9 V). Pulsed I-V measurements confirm that the FeFETs based on HZO (long O-3 of 7 s) show a large MW of 1.0 V with an extremely short delay time of 100 ns between pulses. The improvement in the performance of HZO-based FeFETs suggests a reduction in trap density in the interfacial layer by using a long O-3 injection time.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Sung-Jin Jung, Sang-Soon Lim, Byeong-Hyeon Lee, Sung Ok Won, Hyung-Ho Park, Seong Keun Kim, Jin-Sang Kim, Seung-Hyub Baek
Summary: Solid compounds with volatile elements often deviate from stoichiometric composition during thermal processes, leading to varied properties. Understanding the effect of process parameters on element volatility and how physical properties change with altered stoichiometry is crucial.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Engineering, Electrical & Electronic
Myeong Gil Chae, Jina Kim, Hee Won Jang, Bo Keun Park, Taek-Mo Chung, Seong Keun Kim, Jeong Hwan Han
Summary: High-performance p-type thin-film transistors (TFTs) with high field-effect mobility and high on/off current ratios (Ion/Ioff) were achieved by engineering the microstructure and surface morphology of the atomic layer-deposited (ALD) SnO channel layer. ALD SnO films grown at 225 degrees C exhibited excellent crystallinity and dense, smooth surfaces, resulting in superior field-effect mobility of 6.13-7.24 cm2/V·s without requiring high-temperature post-annealing. Optimization of the SnO channel thickness suppressed off-state leakage current and yielded excellent TFT switching performance with an Ion/Ioff value of 104-105. ALD Al2O3 film backchannel passivation improved subthreshold swing characteristics by reducing surface defect states, highlighting the importance of synergistic control of microstructure, surface morphology, and thickness in ALD SnO channels for high-performance p-type SnO TFTs.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Physics, Applied
Seung Ho Ryu, Jihoon Jeon, Gwang Min Park, Taikyu Kim, Taeyong Eom, Taek-Mo Chung, In-Hwan Baek, Seong Keun Kim
Summary: In this study, the researchers enhanced the performance of p-type SnO thin-film transistors (TFTs) by using an atomic-layer-deposited SnO/high-k structure with crystalline HfO2 as a high-k dielectric. The introduction of an ultrathin Al2O3 layer on the surface of c-HfO2 effectively eliminated grain boundaries and improved the electrical performance of the TFTs. This finding suggests the potential of combining van der Waals semiconductors with high-k dielectrics for advanced device applications.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Ceramics
Seunghyeok Lee, Sung-Jin Jung, Gwang Min Park, Junpyo Hong, Albert S. Lee, Seung-Hyub Baek, Heesuk Kim, Tae Joo Park, Jin-Sang Kim, Seong Keun Kim
Summary: This study demonstrates the use of atomic layer deposition (ALD) to create a thin Al2O3 layer on n-type Bi2Te2.7Se0.3, which helps improve their thermoelectric performance by reducing the adverse effects of multiple boundaries. The ALD cycle effectively suppresses volatilization and reduces the electron concentration while inducing numerous boundaries to decrease thermal conductivity. However, increasing the number of ALD cycles leads to a rise in resistance and degradation of performance. Overall, the ZT value is increased by 51% with a single ALD cycle.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Ah-Jin Cho, Seung Ho Ryu, Jae Gyun Yim, In-Hwan Baek, Jung Joon Pyeon, Sung Ok Won, Seung-Hyub Baek, Chong-Yun Kang, Seong Keun Kim
Summary: Atomic layer deposition (ALD) is a promising growth technique for TMDCs, but the poor crystallinity of ALD-grown TMDCs remains a challenge. This study investigates the growth behavior of highly crystallized MoS2 by ALD, finding that the ALD process facilitates repeated growth and saturation, leading to improved TMDC quality.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
In-Hwan Baek, Ah-Jin Cho, Ga Yeon Lee, Heenang Choi, Sung Ok Won, Taeyong Eom, Taek-Mo Chung, Cheol Seong Hwang, Seong Keun Kim
Summary: Plasma treatment of SiO2 substrate enhances the interfacial properties of ALD-grown SnO films, leading to improved crystallinity, stoichiometry, and field-effect mobility. These findings have implications for future electronics with complementary oxide thin film devices.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
