Article
Chemistry, Physical
Shuo Li, Qiang Wu, Haokun Ding, Songsong Wu, Xinwei Cai, Rui Wang, Jun Xiong, Guangyang Lin, Wei Huang, Songyan Chen, Cheng Li
Summary: In this study, a p-WSe2/n-Ge vdW heterojunction phototransistor with a Schottky barrier collector on n-Ge for broadband photodetection is reported. The phototransistor exhibits high responsivities, photocurrent gain, and fast response time, making it suitable for high-performance broadband photodetection.
Article
Chemistry, Multidisciplinary
Hsun-Jen Chuang, Madeleine Phillips, Kathleen M. McCreary, Darshana Wickramaratne, Matthew R. Rosenberger, Vladimir P. Oleshko, Nicholas Proscia, Mark Lohmann, Dante J. O'Hara, Paul D. Cunningham, C. Stephen Hellberg, Berend T. Jonker
Summary: The appearance of moire Raman modes from nearly aligned WSe2-WS2 van der Waals heterostructures in a certain frequency range indicates sensitivity to twist angle and strong Raman intensity modulation dependent on excitation energy and temperature. These modes exhibit identical frequencies for a given small twist angle and are a consequence of the large moire length scale resulting in zone-folded phonon modes that are Raman active.
Article
Chemistry, Physical
Yupiao Wu, Shuo-En Wu, Jinjin Hei, Longhui Zeng, Pei Lin, Zhifeng Shi, Qingming Chen, Xinjian Li, Xuechao Yu, Di Wu
Summary: This study presents the controllable growth of large-area 2D MoSe2 layers and the fabrication of a high-quality n-MoSe2/p-Si van der Waals heterojunction device. The device exhibited a self-driven broadband photoresponse with impressive responsivity, specific detectivity, and response time. Furthermore, a 4 x 4 integrated heterojunction device array was achieved with good uniformity and satisfying imaging capability. The large-area 2D MoSe2 layer and its heterojunction device array hold great promise for high-performance photodetection and imaging applications in integrated optoelectronic systems.
Article
Chemistry, Applied
Zhongliao Wang, Bei Cheng, Liuyang Zhang, Jiaguo Yu, Youji Li, S. Wageh, Ahmed A. Al-Ghamdi
Summary: Reducing CO2 to hydrocarbon fuels through solar irradiation is a promising approach for mitigating CO2 emissions and resource depletion. However, the catalytic performance is hindered by severe charge recombination and high energy barrier. In this study, a 2D/2D Bi2MoO6/BiOI composite was fabricated to enhance CO2 photoreduction efficiency. The composite showed efficient charge transfer, strong redox capability, and effective charge separation. The intermediates of CO2 photoreduction were identified, and the rate-determining step for CH4 and CO production was determined to be CO2 hydrogenation. Introduction of Bi2MoO6 decreased the energy barrier for CO2 photoreduction on BiOI. The study highlights the synergistic effect of the S-scheme heterojunction and van der Waals heterojunction in the 2D/2D composite.
CHINESE JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Pengyu Li, Yinghe Zhao, Huiqiao Li, Tianyou Zhai
Summary: This study systematically investigates the working mechanisms of Sb2O3 and two Sb2O3-like molecules (As2O3 and Bi2O3) as dielectrics, using a combination of first-principles calculations and gate leakage current theories. It is found that molecules-based vdW dielectrics have a significant advantage over conventional materials, as defects have hardly any impact on their insulating properties. Furthermore, the study reveals that Sb2O3 faces challenges in meeting the requirements for both p-MOS and n-MOS devices, while As2O3 can serve as a dielectric for both types. This research provides a theoretical foundation for the application of molecules-based vdW dielectrics and offers a competitive choice (As2O3) for optimizing the dielectric layer in 2D vdW semiconductor-based CMOS devices, with profound implications for the future semiconductor industry.
Article
Nanoscience & Nanotechnology
Juanjuan Li, Dingwen Cao, Fangfang Chen, Di Wu, Yong Yan, Junli Du, Jinke Yang, Yongtao Tian, Xinjian Li, Pei Lin
Summary: This study introduces a novel wet-chemical thinning method for 2D tellurium, achieving scalability and site-specific thickness patterning capability. A polarity-switchable van der Waals heterodiode with a high rectification ratio is realized based on tellurium/WSe2, demonstrating its electronic application through fabricating a logic half-wave rectifier.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Di Wu, Zhiheng Mo, Yanbing Han, Pei Lin, Zhifeng Shi, Xu Chen, Yongtao Tian, Xin Jian Li, Huiyu Yuan, Yuen Hong Tsang
Summary: The study successfully fabricated a PdSe2/CdTe mixed-dimensional van der Waals heterojunction capable of detecting long-wave infrared radiation at room temperature. The device has a fast response rate, high responsivity, and reasonable specific detectivity, making it suitable for detecting short pulse infrared signals and highly sensitive to polarized infrared light signals.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Yabing Shan, Xiaofei Yue, Jiajun Chen, Borgea G. M. Ekoya, Jinkun Han, Laigui Hu, Ran Liu, Zhi-Jun Qiu, Chunxiao Cong
Summary: This study investigates the strain engineering of a bilayer WS2/WSe2 vertical heterostructure on the nanoscale using Raman and photoluminescence spectroscopy. The results show that the original coupling strength of the heterostructure significantly affects the electronic band structure evolution and interlayer exciton behavior.
ACS APPLIED NANO MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Jinjin Hei, Xue Li, Shuoen Wu, Pei Lin, Zhifeng Shi, Yongtao Tian, Xinjian Li, Longhui Zeng, Xuechao Yu, Di Wu
Summary: Conventional methods of chemical vapor deposition and mechanical exfoliation fail to meet the demands for integrated optoelectronics and systems. Therefore, we propose a simple selenization approach to grow wafer-scale 2D p-WSe2 layers with high uniformity and customized patterns. The fabricated self-driven broadband photodetector exhibits high responsivity, large specific detectivity, and remarkable nanosecond response speed.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Weiqi Dang, Bei Zhao, Chang Liu, Xiangdong Yang, Lingan Kong, Zheyi Lu, Bo Li, Jia Li, Hongmei Zhang, Wanying Li, Shun Shi, Ziyue Qin, Lei Liao, Xidong Duan, Yuan Liu
Summary: This study introduces a van der Waals (vdW) integration route for highly reliable gate metal integration on porous dielectrics. The physical lamination process employed by the vdW integration avoids the direct deposition of metal electrodes into porous dielectrics to ensure reliable gate integration and produce low gate leakage devices.
Article
Chemistry, Physical
Huadong Zeng, Xiangyue Liu, Hong Zhang, Xinlu Cheng
Summary: This study investigated the photoinduced carrier transfer dynamics in the WS2/WSe2 heterostructure, revealing that stacking configurations can affect the time scales of ultrafast hole and electron transfer. Different stacking configurations have significant differences in carrier transfer pathways, while temperature has minimal impact on electron transfer dynamics.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Changxiu Li, Alexey V. V. Scherbakov, Pedro Soubelet, Anton K. K. Samusev, Claudia Ruppert, Nilanthy Balakrishnan, Vitalyi E. E. Gusev, Andreas V. V. Stier, Jonathan J. J. Finley, Manfred Bayer, Andrey V. V. Akimov
Summary: The development of new techniques for ultrafast control of physical properties in 2D van der Waals nanolayers is necessary due to the increasing role of 2D devices. Heterobilayers assembled from van der Waals monolayers have the special feature of femtosecond separation of photoexcited electrons and holes between neighboring layers, resulting in the formation of Coulomb force. Coherent phonons generated in MoSe2/WSe2 heterobilayers through laser pulses can modulate the thickness of the heterobilayer and the photogenerated electric field in the van der Waals gap. Additionally, the modulation of the van der Waals gap by coherent phonons enables the generation of THz radiation in 2D nanodevices with van der Waals heterobilayers.
Article
Nanoscience & Nanotechnology
Wen Jin, Gaojie Zhang, Hao Wu, Li Yang, Wenfeng Zhang, Haixin Chang
Summary: This study demonstrates a room-temperature magnetic tunnel junction (MTJ) based on a Fe3GaTe2/WS2/Fe3GaTe2 heterostructure, which exhibits a tunneling magnetoresistance (TMR) ratio of up to 213% and a high spin polarization of 72% at 10 K, the highest reported in Fe3GaTe2-based MTJs so far. The MTJ also maintains a robust tunneling spin-valve signal at room temperature (300 K) with low bias currents, offers potential for low-energy consumption in all-2D vdW spintronics and provides alternative routes for electronic control of spintronic devices.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Jisu Jang, Hyun-Soo Ra, Jongtae Ahn, Tae Wook Kim, Seung Ho Song, Soohyung Park, Takashi Taniguch, Kenji Watanabe, Kimoon Lee, Do Kyung Hwang
Summary: Graphene technology brings new opportunities for innovation in the field of biomedicine, enabling the fabrication of various functional nanomaterials and precise control and modulation of cells and tissues through the manipulation of its surface properties and structural changes.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Sihao Xia, Yuyan Wang, Hongkai Shi, Yu Diao, Caixia Kan
Summary: Metal decoration plays a critical role in the design of optoelectronic properties based on graphitic thin semiconductors. We propose a computational methodology to investigate the influences of metal nanoclusters on the structural and electronic properties of a GaN/WS2 heterojunction. We observe deformation on the GaN side after metal deposition and changes in work function and charge transfer.
APPLIED SURFACE SCIENCE
(2022)
Article
Energy & Fuels
Jihoon Park, Woong-Joon Ko, Dong-Seok Kang, Yoonmyung Lee, Jung-Hoon Chun
Article
Chemistry, Analytical
Hassan Saif, Muhammad Bilawal Khan, Jongmin Lee, Kyoungho Lee, Yoonmyung Lee
Article
Energy & Fuels
Muhammad Bilawal Khan, Hassan Saif, Yoonmyung Lee
Article
Engineering, Electrical & Electronic
Hyungmin Gi, Junyoung Park, Yeohoon Yoon, Seungchul Jung, Sang Joon Kim, Yoonmyung Lee
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2020)
Article
Automation & Control Systems
Kyoungjin Lee, Haneul Kim, Jehyung Yoon, Hyoung-Seok Oh, Jin-Hong Park, Byeong-Ha Park, Hojin Park, Yoonmyung Lee
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2020)
Article
Engineering, Electrical & Electronic
Jongmin Lee, Donghyeon Lee, Yongmin Lee, Yoonmyung Lee
Summary: The study introduces a leakage-based PUF for cost-effective security of IoT devices. By utilizing a specific method to generate response key bits and proposing a lossless stabilization scheme to improve system stability, the proposed method achieves high stability without any key losses.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2021)
Article
Chemistry, Analytical
Muhammad Bilawal Khan, Hassan Saif, Kyoungho Lee, Yoonmyung Lee
Summary: A novel energy harvesting interface using piezoelectric transducers is proposed for high-voltage energy harvesting, with pre-biasing of the PZT increasing damping force for higher energy extraction. The approach invests energy into the PZT only when deformation is detected, and stored energy is used to pre-bias the PZT for enhanced extraction. This interface successfully harvests energy from excitations with open-circuit voltages up to 100V.
Article
Engineering, Electrical & Electronic
Gicheol Shin, Eunyoung Lee, Jongmin Lee, Yongmin Lee, Yoonmyung Lee
Summary: The REFF flip-flop eliminates redundancies to achieve low-power and reliable operation, working reliably down to 0.31 V. Tests have shown significant power reduction compared to conventional flip-flops, with the REFF remaining functional at as low as 0.28 V.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2021)
Article
Engineering, Electrical & Electronic
Yeohoon Yoon, Hyungmin Gi, Jongmin Lee, Minsik Cho, Changyoun Im, Yongmin Lee, Chisung Bae, Sang Joon Kim, Yoonmyung Lee
Summary: This paper introduces an energy-harvesting interface that combines a continuously scalable-conversion-ratio switched-capacitor dc-dc converter with maximum power point tracking. By utilizing the unique characteristics of the converter, real-time power monitoring and variation-tolerant MPPT for various energy sources are achieved. The voltage range is extended by a step-up/down convertible converter, and the efficiency is improved with matrix-structured and load-mapped power switches. The test chip shows high peak conversion efficiency and average efficiency, and the MPPT efficiency is confirmed with a solar cell.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2022)
Article
Engineering, Electrical & Electronic
Soyoun Jeong, Jaerok Kim, Minhyeok Jeong, Yoonmyung Lee
Summary: In this study, a novel Resistive random access memory (ReRAM)-based Compute-in-memory (CIM) macro is proposed to improve the accuracy and throughput of conventional ReRAM-based CIM macros. The proposed structure consists of 1T2R1C bit-cells and a 4-kb ReRAM-based nvCIM architecture with ternary weight and input. The results show that the proposed CIM macro has high variation tolerance, high throughput, and less sensitivity to low R-ratios, achieving high ternary DNN accuracy even with low R-ratios and variations.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2022)
Article
Engineering, Electrical & Electronic
Jongmin Lee, Minsun Kim, Minhyeok Jeong, Gicheol Shin, Yoonmyung Lee
Summary: This paper introduces a current-integration-based differential NAND-structured PUF, which achieves higher sensitivity to threshold voltage variation and more stable response generation compared to weak inversion operation, while maintaining faster speed.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2022)
Article
Engineering, Electrical & Electronic
Gicheol Shin, Eunyoung Lee, Jongmin Lee, Yongmin Lee, Yoonmyung Lee
Summary: A static contention-free differential flip-flop (SCDFF) is introduced for low-voltage and low-power applications, offering fully static and contention-free operation and wide-range voltage scalability.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2023)
Article
Computer Science, Hardware & Architecture
Gicheol Shin, Eunyoung Lee, Jongmin Lee, Yongmin Lee, Yoonmyung Lee
IEEE SOLID-STATE CIRCUITS LETTERS
(2020)
Article
Computer Science, Information Systems
Yongmin Lee, Gicheol Shin, Yoonmyung Lee
Article
Computer Science, Hardware & Architecture
Jongmin Lee, Minsun Kim, Gicheol Shin, Yoonmyung Lee
IEEE SOLID-STATE CIRCUITS LETTERS
(2019)
