Article
Chemistry, Multidisciplinary
Dong Jin Jang, Mohd Musaib Haidari, Jin Hong Kim, Jin-Yong Ko, Yoonsik Yi, Jin Sik Choi
Summary: Graphene has great potential for use in electronic devices due to its unique electrical properties. However, the traditional wet transfer technique leaves microscale impurities from the substrate, degrading the electrical performance of the graphene. To address this issue, a modified transfer process using a temporary UV-treated SiO2 substrate was introduced to adsorb impurities from the graphene before transferring it to the final substrate. The retransferred graphene showed improved electron-hole asymmetry and sheet resistance, indicating that the impurities were eliminated. Overall, this modified transfer process is a promising method for obtaining high-quality graphene for industrial-scale electronic devices.
Article
Nanoscience & Nanotechnology
Zhongzheng Huang, Junku Liu, Tianfu Zhang, Yuanhao Jin, Jiaping Wang, Shoushan Fan, Qunqing Li
Summary: The study showed that graphene/HfO2/Si photodetector has a stronger interfacial gating effect compared to graphene/SiO2/Si. The high efficiency was attributed to the higher interface state density at the HfO2/Si interface and the higher dielectric constant of the HfO2 layer. By utilizing the interfacial gating mechanism, fast response, high photoresponsivity, and ultrabroadband photodetection were achieved simultaneously, offering potential for electronic and optoelectronic applications.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Seung-Mo Kim, Ho-In Lee, Yongsu Lee, So-Young Kim, Tae Jin Yoo, Sunwoo Heo, Soo Cheol Kang, Hyeon Jun Hwang, Byoung Hun Lee
Summary: A new non-destructive defect analysis method AMDCA was reported to assess the defect density and energy levels in graphene and other two-dimensional materials. The method was validated by observing charge trap densities in a graphene field-effect transistor experiment. This method can be valuable for studying graphene devices and other 2D materials without body contacts.
Article
Materials Science, Composites
Sijia Hao, Zheling Li, Cheng Yang, Alexander J. Marsden, Ian A. Kinloch, Robert J. Young
Summary: Bio-inspired nanocomposites were fabricated using GO-based fillers and their interfacial energy dissipation during cyclic deformation was studied. It was found that the presence of functional groups reduced the interfacial energy dissipation in the elastic regime, but increased it with strain. This study provides new insights for the fabrication and evaluation of bio-inspired nanocomposites.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Changhua Li, Xiaoning Yang, Yannan Guo
Summary: In this study, the first-principle density functional theory (DFT) method was used to investigate the interfacial interaction and electronic properties of graphene on beta-cristobalite SiO2 surface. The results showed that the Si-terminated beta-cristobalite SiO2 substrate exhibits a strong chemical covalent interaction with graphene, while the hydroxylated SiO2 surface only shows weak van der Waals interaction with graphene. The presence of interlayer water molecules between graphene and SiO2 reduces the adhesion energy for the graphene/SiO2 composites. The study also found that the surface polarity of SiO2 and the interfacial water geometry have an impact on the electronic properties of graphene.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Physical
Yang Liu, Wenhao Wu, Shixian Yang, Ping Yang
Summary: The thermal transport performance and thermal rectification characteristics of graphene/MoS2 heterointerface (G/M) are comprehensively studied in this paper. The influence of vacancy defects and temperature on the interfacial thermal conductance (G) is investigated. The results provide theoretical support for the application of graphene/MoS2 heterojunctions in heat rectifier devices.
SURFACES AND INTERFACES
(2022)
Article
Materials Science, Composites
Fei Yan, Liu Liu, Kaixuan Li, Lin Jin, Mengjie Zhang, Yu Liu, Linghan Xiao, Yuhui Ao
Summary: A novel method of pi bridging between graphene oxide and carbon fiber was presented without the need for chemical treatment, resulting in improved performance of composites without damaging the carbon fiber. The introduced bridging agent significantly increased interlaminar shear strength, transverse fiber bundle strength, and interfacial shear strength of the composites.
COMPOSITES SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Physical
Patrick Fiorenza, Corrado Bongiorno, Filippo Giannazzo, Mario S. Alessandrino, Angelo Messina, Mario Saggio, Fabrizio Roccaforte
Summary: This study investigates the impact of SiO2 layers on 4H-SiC, with findings indicating that NO annealing can enhance channel mobility and reduce the total amount of interface states. Electron energy loss spectroscopy reveals that the reduction of traps in the NO annealed sample is attributed to lower amounts of sub-stoichiometric silicon oxide and carbon-related defects at the interface.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Wang Liang, Chunhe Jiang, Kejiang Li, Jianliang Zhang, Zhisheng Bi
Summary: Graphene has attracted significant research attention in the field of materials due to its exceptional properties and unique two-dimensional structure. This study employs molecular dynamics simulation methods to investigate the wetting behavior of molten iron on the surface of graphene, focusing on the influence of different graphene wrinkles. The results reveal that the flatness of graphene plays a crucial role in determining the wetting properties of molten iron.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Eui Young Choi, Seok Hyeon Hong, Byeong Kook Park, Prahallad Padhan, Wilfrid Prellier, Seung Young Park, Younghun Jo, Byeong Cheol Min, Ji Won Seo
Summary: A systematic study on electrically controlled magnetization in tri-layers of ferromagnetic SrRuO3 and antiferromagnetic insulating manganites reveals that interface-driven magnetic inhomogeneity can act as a bridge between current and magnetism, leading to new functionalities in heterostructures.
APPLIED SURFACE SCIENCE
(2021)
Review
Chemistry, Multidisciplinary
Sihua Guo, Jin Chen, Yong Zhang, Johan Liu
Summary: Graphene-based film is of interest in various applications due to its excellent thermal, electrical, and mechanical properties. Methods to improve its properties, such as blade coating technology, have been explored. Different interface interactions can enhance the mechanical properties of graphene-based film, with applications in areas like mobile phones showcasing its potential.
Article
Nanoscience & Nanotechnology
Qi Yan, Biao Chen, Wenting Ye, Jie Wan, Tao Zhang, Hongchao Kou, Qin Zhou, Wenfeng Lu, Hao Wang, Jianghua Shen, Haifeng Wang, Jinshan Li
Summary: The lubricant effect of graphene in metals during friction and wear is difficult to achieve. This study improved the interface of composites by decorating few-layered graphene with SiC nanoparticles, resulting in significantly enhanced antiwear performance.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Qian Zhang, Zonglin Yi, Ying Liu, Peide Han, Jun Mei
Summary: Graphene-embedded Cu matrix composites have great potential in various engineering fields, but weak interfacial interactions between the metallic matrix and carbonaceous graphene pose a major issue. By incorporating heterogeneous alloying elements into the Cu matrix to reconstruct the graphene-Cu interface, the tensile properties of GE-CMCs can be significantly improved.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Mechanical
Haiying Yang, Yunqing Tang, Ping Yang
Summary: We investigated the bonding configurations, failure mechanisms, and thermal reliabilities of graphene interfaces with Si and SiC substrates. It was found that covalent bonds prefer to form between Si-terminated substrates and strain-released graphene, while the graphene/SiC interface tends to have denser covalent bonds. The failure of the graphene/Si interface is mainly caused by the debonding of Si-Si bonds connecting to interfacial C-Si bonds, while the graphene/SiC interface mainly fails due to the failure of graphene. Higher interfacial bonding density enhances the interfacial strength, but too many interfacial covalent bonds can weaken the strength of graphene. Proper thermal shock treatment can improve the bonding strength and interfacial thermal reliabilities of the graphene/semiconductor interfaces.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Asif A. Nabiyev, Andrzej Olejniczak, Akhmed Kh. Islamov, Andrzej Pawlukojc, Oleksandr I. Ivankov, Maria Balasoiu, Alexander Zhigunov, Musa A. Nuriyev, Fovzi M. Guliyev, Dmytro V. Soloviov, Aidos K. Azhibekov, Alexander S. Doroshkevich, Olga Yu. Ivanshina, Alexander I. Kuklin
Summary: This study investigated the influence of SiO2 and ZrO2 nanoparticle fillers on the structural properties of HDPE nanocomposites using a variety of characterization methods. The results showed that the particle size and crystallinity of the fillers changed with increasing filler content, and their mechanisms of action in the composite materials were also different.
Article
Chemistry, Multidisciplinary
Tae Jin Yoo, Wan Sik Kim, Kyoung Eun Chang, Cihyun Kim, Min Gyu Kwon, Ji Young Jo, Byoung Hun Lee
Summary: A graphene photodetector decorated with Bi2Te3 nanowires demonstrated high gain and wide bandwidth window. The photoconductive gain was significantly improved compared to a graphene/Bi2Te3 nanoplate junction, and the position of photocurrent generation was investigated. By utilizing low bandgap Bi2Te3 nanowires and a graphene junction, the photoresponsivity was increased effectively.
Article
Nanoscience & Nanotechnology
Hyeon Jun Hwang, Sang Kyung Lee, Seung Mo Kim, Byoung Hun Lee
Summary: A novel method is developed to analyze the ferroelectric switching behaviors of Hf0.5Zr0.5O2 (HZO) gate dielectric using the unique charge response characteristics of graphene field effect transistor (GFET). The trans-conductance of GFET with ferroelectric HZO is observed to be increased by 610% in DC measurement with minimal hysteresis, while fast pulse I-V analysis reveals that the improved swing and small hysteresis are the result of compensation between bulk charge trapping and dipole charges.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Ki-Dong Lim, Hun-Kook Choi, Ik-Bu Sohn, Byeong-Ha Lee, Jin-Tae Kim
Summary: A new method for fabricating a lensed fiber with a desired focal length using femtosecond and CO2 lasers is proposed, achieving greater precision and efficiency compared to conventional methods.
APPLIED SCIENCES-BASEL
(2021)
Article
Nanoscience & Nanotechnology
Myungwoo Son, Jaewon Jang, Yongsu Lee, Jungtae Nam, Jun Yeon Hwang, In S. Kim, Byoung Hun Lee, Moon-Ho Ham, Sang-Soo Chee
Summary: The study demonstrates the fabrication of a Cu-graphene heterostructure interconnect by synthesizing graphene directly on a Cu interconnect, resulting in enhanced electrical properties and reliability compared to pure Cu interconnects. The doping of graphene to increase carrier density significantly improves the reliability of the graphene-capped interconnect, showing compatibility with practical applications such as next-generation interconnect materials in CMOS back-end-of-line (BEOL).
NPJ 2D MATERIALS AND APPLICATIONS
(2021)
Article
Chemistry, Physical
Seung-Mo Kim, Ho-In Lee, Yongsu Lee, So-Young Kim, Tae Jin Yoo, Sunwoo Heo, Soo Cheol Kang, Hyeon Jun Hwang, Byoung Hun Lee
Summary: A new non-destructive defect analysis method AMDCA was reported to assess the defect density and energy levels in graphene and other two-dimensional materials. The method was validated by observing charge trap densities in a graphene field-effect transistor experiment. This method can be valuable for studying graphene devices and other 2D materials without body contacts.
Article
Optics
Tae Jin Yoo, So-Young Kim, Min Gyu Kwon, Cihyun Kim, Kyoung Eun Chang, Hyeon Jun Hwang, Byoung Hun Lee
Summary: In this study, simultaneous optimization of detectivity and dark current in a graphene/p-type silicon photodetector was achieved by modulating the Schottky barrier height through doping graphene with polyethyleneimine (PEI). Doping graphene with PEI resulted in a three orders of magnitude reduction in dark current and a 529% improvement in detectivity at 850 nm compared to undoped graphene/p-type silicon photodetectors. These results highlight the effectiveness of chemical doping of graphene as a simple and efficient approach to enhance the detectivity of heterojunction photodetectors.
LASER & PHOTONICS REVIEWS
(2021)
Article
Materials Science, Multidisciplinary
So-Young Kim, Jiae Yoo, Hyeon Jun Hwang, Byoung Hun Lee
Summary: The study demonstrated a universal ternary device that can be programmed into n-type and p-type ternary devices, and showed the feasibility of a standard ternary inverter function through discretely programmed graphene channels. The concept of programmable ternary logic, based on channel width modulation and ferroelectric doping, is valuable for future experimental studies on multi-valued logic architecture.
ORGANIC ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Ho-In Lee, So-Young Kim, Seung-Mo Kim, Yongsu Lee, Hae-Won Lee, Sung Ho Yu, Hyeon Jun Hwang, Myung Mo Sung, Byoung Hun Lee
Summary: This work investigates the scaling prospect of ZnO stacked nanosheet channel ternary field effect transistor, as well as the impact of scaling geometric parameters on its performance. The results show that compared to other ternary logic devices, this device has lower power consumption and higher noise margin in the intermediate state. The feasibility for stable ternary circuit operation is also confirmed.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Cihyun Kim, Tae Jin Yoo, Min Gyu Kwon, Kyoung Eun Chang, Hyeon Jun Hwang, Byoung Hun Lee
Summary: The structure of a gate-controlled graphene/germanium hybrid photodetector was optimized by splitting the active region, resulting in significantly improved infrared detection capability.
Article
Optics
Min Gyu Kwon, Cihyun Kim, Kyoung Eun Chang, Tae Jin Yoo, So-Young Kim, Hyeon Jun Hwang, Sanghan Lee, Byoung Hun Lee
Summary: In this paper, we improved the performance of a near-infrared graphene/germanium heterojunction photodetector by doping graphene with p-type chemical, which lowered the Fermi level and increased the Schottky barrier. The responsivity and detectivity were significantly improved, making it valuable for the development of graphene/semiconductor based photodetectors and near-infrared sensors.
Article
Chemistry, Analytical
Myeongseop Kim, Bobae Cho, Hansol Lee, Taeil Yoon, Byeongha Lee
Summary: In this study, a hemispherical resonator gyroscope (HRG) was implemented using a consumer wineglass as the resonator and 3 x 3 optical interferometers as the detectors. The low quality of the off-the-shelf wineglass as a resonator was overcome by the high performance of the optical interferometer. The asymmetries in stiffness and absorption of the resonator were analyzed theoretically and confirmed experimentally. The straightness of the amplitude ratio of two n = 2 fundamental resonant modes of the resonator in a complex plane was proven. By utilizing this straightness and the high performance of the optical interferometer, four real constant parameters characterizing the HRG system were extracted. Experimental results showed that it was possible to measure the Coriolis force at the level of industrial grade using a resonator with an average resonance frequency of 444 Hz and Q value of 1477.2, and achieve a small bias stability of 2.093 degrees/h.
Article
Materials Science, Multidisciplinary
Soo Cheol Kang, Hyun-Wook Jung, Sung-Jae Chang, Ilgyu Choi, Sang Kyung Lee, Seung Mo Kim, Byoung Hun Lee, Ho-Kyun Ahn, Jong -Won Lim
Summary: AlGaN/GaN MIS-HEMTs fabricated with a recess gate exhibit sensitivity to changes in the polarity of the gate voltage. Under negative gate bias stress, electron detrapping requires overcoming an energy barrier, leading to increased temperature dependence. Degradation occurs primarily at the Al2O3/AlGaN interface rather than in the channel or mobility. During relaxation, the time exponent of V-T shift is relatively low, which may be attributed to further degradation at the broader energy levels of the Al2O3/AlGaN interface.
CURRENT APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Hyeon Jun Hwang, So-Young Kim, Sang Kyung Lee, Byoung Hun Lee
Summary: This study investigated the performance of a thermoelectric device made of centimeter-scale monolayer graphene. The carrier type and junction profile of the active graphene layer were modified through chemical doping. After device optimization, improvements in carrier concentration of at least 200% and enhancements in power factor of at least 600% were achieved. Under optimal conditions, a maximum Seebeck coefficient of -350 mu V/K and power factor of -14000 mu W/mK^2 were obtained, which are at least three times higher than the best values reported for other graphene-based thermoelectric devices.
Article
Chemistry, Multidisciplinary
Hyeon Jun Hwang, So-Young Kim, Sang Kyung Lee, Byoung Hun Lee
Summary: By modifying the Fermi level of large-area graphene using an external electric field, researchers have experimentally investigated a reconfigurable passive device that can manipulate its resonant frequency by controlling its quantum capacitance value without complicated equipment. When the total capacitance change caused by the gate bias increased to 60% compared to the initial state, a 6% shift in the resonant frequency could be achieved. Although the signal characteristics of the graphene antenna are slightly inferior to conventional metal antennas, simplifying the device structure allows reconfigurable characteristics to be implemented using only the gate bias change.
Article
Engineering, Electrical & Electronic
Tae Jin Yoo, Hyeon Jun Hwang, Soo Cheol Kang, Sunwoo Heo, Ho-In Lee, Young Gon Lee, Hokyung Park, Byoung Hun Lee
Summary: Barrier height, trap state, bandgap, and band alignment information of the metal-ZrO2-metal capacitor were extracted using internal photoemission (IPE) system. By correlating the IPE analysis with I-V and C-V characteristics before and after rapid thermal annealing, the origin and transformation of defect states were successfully investigated. The analysis revealed that deep-level defects originating from oxygen vacancies near the top electrode are the cause of leakage current in MIM capacitor, which can be effectively reduced by proper thermal annealing.
IEEE JOURNAL OF THE ELECTRON DEVICES SOCIETY
(2021)
