Article
Chemistry, Multidisciplinary
Yuan Li, Yanguang Cui, Mingjia Zhang, Xiaodong Li, Ru Li, Wenyan Si, Quanhu Sun, Lingmin Yu, Changshui Huang
Summary: In this study, a highly sensitive pressure sensor sponge was prepared, enabling wearable health monitoring with ultra-sensitive pressure sensing. The use of liquid metal in the sponge structure allows for adjustment of the contact area, facilitating fast response and recovery time. The sensor accurately monitors various human activities.
Article
Materials Science, Multidisciplinary
Gwangtaek Oh, Ji Hoon Jeon, Young Chul Kim, Yeong Hwan Ahn, Bae Ho Park
Summary: The study introduces a graphene/MoSe2 barristor with a high on/off ratio and external quantum efficiency. By applying an electric field to the gate electrode, the photocurrent of the barristor can be modulated, resulting in a high gate tuning ratio.
NPG ASIA MATERIALS
(2021)
Article
Multidisciplinary Sciences
Yongsu Lee, Seung-Mo Kim, Kiyung Kim, So-Young Kim, Ho-In Lee, Heejin Kwon, Hae-Won Lee, Chaeeun Kim, Surajit Some, Hyeon Jun Hwang, Byoung Hun Lee
Summary: This report demonstrates a P-type ternary device with controllable threshold voltage values, showing three distinct electrical output states using a special structure. It also proves the feasibility of designing a complementary standard ternary inverter around 1V.
SCIENTIFIC REPORTS
(2022)
Article
Nanoscience & Nanotechnology
Yu Jiang, Junlin Ma, Liuxue Shen, Wenrui Zhang, Kai Yang, Boyu Zhu, Yupeng Yang, Hongting Ma, Xize Chen, Shubin Bai, Nan Zhu
Summary: A wearable smart-sensing platform using silk fibroin-reduced graphene oxide has been developed, which integrates noncontact moisture/thermo sensing and Joule heating. It has the capabilities of touch-free humidity/temperature sensing, breath monitoring, and mental state prediction.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Dong-Ho Shin, Young Gyu You, Sung Il Jo, Goo-Hwan Jeong, Eleanor E. B. Campbell, Hyun-Jong Chung, Sung Ho Jhang
Summary: This study reports a graphene/carbon-nanotube electronic device that can be utilized in the fabrication of complementary logic circuits. A complementary inverter is designed and demonstrated, showing low power consumption and excellent switching characteristics.
Article
Nanoscience & Nanotechnology
Carsten Strobel, Carlos A. Chavarin, Karola Richter, Martin Knaut, Johanna Reif, Sandra Voelkel, Andreas Jahn, Matthias Albert, Christian Wenger, Robert Kirchner, Johann W. Bartha, Thomas Mikolajick
Summary: In this study, a novel graphene-based transistor called graphene adjustable-barriers transistor (GABT) was proposed and analyzed. It utilizes a semiconductor-based gate to modulate the device currents, overcoming the low on/off ratios and insufficient current saturation of conventional graphene transistors.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Analytical
Xin Cao, Kunpeng Zhang, Guang Feng, Quan Wang, Peihong Fu, Fengping Li
Summary: Flexible pressure sensors are widely used in electronic skins, health monitoring, and human-machine interfaces. This study reports a credibility strategy for growing high-quality vertical graphene (VG) directly on a flexible and stretchable mica paper dielectric substrate, resulting in a flexible, touchable pressure sensor with low power consumption and portability. The graphene-based sensor exhibits high sensitivity, a wide pressure range, and strong stability.
Article
Engineering, Electrical & Electronic
Daohan Ge, Abubakar A. Babangida, Zhou Hu, Liqiang Zhang, Minchang Wang
Summary: This study fabricates a graphene-elastomer pressure sensor through rapid thermal annealing process and demonstrates its excellent sensitivity and stretchability. The sensor shows good performance in detecting subtle pressure in the low-pressure range and potential application in human motion monitoring.
IEEE SENSORS JOURNAL
(2022)
Article
Instruments & Instrumentation
Kazuki Tonomura, Annie Yu, Yuya Ishii
Summary: Attention toward automated driving has increased recently. This study presents an active signal-generating touch/pressure sensor that can detect different actions on the steering wheel. The sensor utilizes electromagnetic waves emitted by electrical appliances and cables to operate and can be used in electric and autonomous vehicles.
SMART MATERIALS AND STRUCTURES
(2023)
Article
Chemistry, Multidisciplinary
Prabhat Kumar, Martin Silhavik, Zahid Ali Zafar, Jiri Cervenka
Summary: This study presents a contact resistance-controlled electromechanical sensor that enables superfast, ultrasensitive, and quantitative measurements of compressive and tensile stress. The research demonstrates the potential of contact resistance-controlled sensing and provides new opportunities for applications in human-machine interfaces, robotics, flexible electronics, and haptic technology.
Article
Chemistry, Multidisciplinary
Junqiang Wang, Zehua Zhu, Yue Qi, Mengwei Li
Summary: A novel crossbeam structure with a graphene varistor protected by Si3N4 is proposed for N/MEMS mechanical sensors, which exhibits excellent mechanoelectrical coupling performance and high sensitivity.
Article
Chemistry, Multidisciplinary
Srinivasarao Yaragalla, Simeone Dussoni, Muhammad Zahid, Marco Maggiali, Giorgio Metta, Athanassia Athanasiou, Ilker S. Bayer
Summary: Stretchable capacitive tactile sensors were fabricated using conductive graphene nanoplatelets (GNPs) or carbon nanofibers (CNFs) coatings on stretchable nitrile rubber sheets. CNF-based coatings showed lower sheet resistance and better current transmission under elongation compared to GNP-based coatings. Structural damages within the coatings could be healed by a rapid heat annealing process, restoring to initial current.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2021)
Article
Chemistry, Physical
Seonghoon Jang, Yongjun Kim, Jihoon Jeon, Seonggil Ham, Sanghyeon Choi, Jehyeon Yang, Seong Keun Kim, Sanghun Jeon, Jingon Jang, Gunuk Wang
Summary: This study introduces a novel three-terminal vertical device called ferroelectric synaptic barristor (FSB), which can function as an energy-efficient artificial synapse for neuromorphic computing. By using electrostatic gating, the FSB can simultaneously change the polarization degree and direction of the thin film and the Schottky barrier and trapping degree at the graphene interface. The FSB exhibits stable long-term potentiation/depression and has better accuracy, fast learning ability, and low energy consumption.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Thi Phuong-Anh Bach, Syed Hassan Abbas Jaffery, Dinh Cong Nguyen, Asif Ali, Sajjad Hussain, Muhammad Hussain, Yongho Seo, Jongwan Jung
Summary: This study presents a three-terminal device with a tunable Schottky barrier for controlling charge transport in a vertically stacked structure called barristor. The device consists of a graphene/rhenium diselenide p-n heterojunction, combining the high mobility of graphene with tunable properties of rhenium diselenide. By modulating the gate voltage, the Schottky barrier height at the graphene/rehenium diselenide interface can be adjusted, resulting in improved carrier transport and optoelectronic characteristics. The device shows promising rectification behavior and sensitivity to incident power density, making it a potential candidate for high-performance graphene-based heterojunction devices.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Electrical & Electronic
Kequan Xia, Zhiwei Xu
Summary: With the advancement of artificial intelligence, research on touch sensors has become popular. A new triboelectric nanogenerator based on a facial mask has been proposed, which can harvest mechanical energy and serve as a flexible touch sensor. The generator demonstrates excellent performance, driving commercial electronics and being harmless to human skin.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Engineering, Electrical & Electronic
Jun-Young Park, Tae Jin Yoo, Ji-Man Yu, Byoung Hun Lee, Yang-Kyu Choi
Summary: This work experimentally confirmed the relationship between passivation gas species and curing characteristics during transistor-level annealing, and it was found that the existence of deuterium in a device was strongly associated with curing behavior.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Cihyun Kim, Tae Jin Yoo, Kyoung Eun Chang, Min Gyu Kwon, Hyeon Jun Hwang, Byoung Hun Lee
Summary: The performance of a graphene/Ge Schottky junction near-infrared photodetector is significantly enhanced by inserting a thin Al2O3 interfacial layer between graphene and Ge. Dark current is reduced by two orders of magnitudes, and the specific detectivity is improved to 1.9 x 10(10) cm . Hz(1/2)W(-1). The responsivity is improved to 1.2 AW(-1) with an interfacial layer from 0.5 AW(-1) of the reference devices. The normalized photo-todark current ratio is improved to 4.3 x 10(7) W-1 at a wavelength of 1550 nm, which is 10-100 times higher than those of other Ge photodetectors.
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
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
Chemistry, Multidisciplinary
Asif Ali, So-Young Kim, Muhammad Hussain, Syed Hassan Abbas Jaffery, Ghulam Dastgeer, Sajjad Hussain, Bach Thi Phuong Anh, Jonghwa Eom, Byoung Hun Lee, Jongwan Jung
Summary: The electronic properties of single-layer, CVD-grown graphene were affected by deep ultraviolet (DUV) light irradiation in different radiation environments, leading to p-type or n-type doping. The degree of doping increased with exposure time, with n-type doping in vacuum reaching saturation after 60 minutes. Additionally, p-type doping in air exhibited higher stability, while n-type doping in nitrogen gas was relatively unstable over time.
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.
