Article
Chemistry, Multidisciplinary
Anna Kuzmina, Markus Parzefall, Patrick Back, Takashi Taniguchi, Kenji Watanabe, Achint Jain, Lukas Novotny
Summary: By controlled stacking of graphene layers, the limitation of single-layer graphene as a material for light-emitting devices has been overcome, enabling twist-controlled resonant light emission. Experimental findings show light emission irrespective of the crystallographic alignment between the graphene electrodes, with a spectrally tunable resonant peak in the near-infrared range.
Article
Chemistry, Multidisciplinary
Zongqi Bai, Yang Xiao, Qing Luo, Miaomiao Li, Gang Peng, Zhihong Zhu, Fang Luo, Mengjian Zhu, Shiqiao Qin, Kostya Novoselov
Summary: The emergence of two-dimensional materials has led to important applications in electronic and optoelectronic devices. However, there are limitations such as low ON/OFF ratio and Schottky barrier formation. In this study, highly tunable field-effect tunneling transistors based on vertical graphene-WS2-graphene heterostructures were demonstrated, overcoming these limitations and achieving low off-state current, high ON/OFF ratio, and controllable carrier transport polarity.
Article
Chemistry, Multidisciplinary
Qiucheng Li, Xiaolong Liu, Eden B. Aklile, Shaowei Li, Mark C. Hersam
Summary: The study reports the self-assembly of mixed-dimensional lateral heterostructures consisting of 2D metallic borophene and 1D semiconducting armchair-oriented graphene nanoribbons (aGNRs). The systematic study and refinement of on-surface polymerization process from monomers to organometallic intermediates to demetallization result in borophene/aGNR lateral heterojunctions with structurally and electronically abrupt interfaces, providing insight for precise nanoelectronics.
Article
Chemistry, Physical
Guangyuan Han, Huan Shan, Lizhi Zhang, Wenpeng Xu, Zhao-Yan Gao, Hui Guo, Geng Li, Hong-Jun Gao
Summary: Twisted graphene/silicene bilayers have been successfully constructed on Ru (0001) crystal via intercalation, providing a new pathway towards the construction of graphene-based twisted heterobilayers.
Article
Chemistry, Physical
Nguyen T. T. Binh, Cuong Q. Nguyen, Tuan V. Vu, Chuong Nguyen
Summary: In this study, ultra-thin van der Waals heterostructures were constructed between graphene and a new 2D Janus MoGeSiN4 material to investigate their interfacial electronic properties and tunable Schottky barriers. The results showed that the graphene/MoGeSiN4 heterostructures have high carrier mobility, making them suitable for high-speed nanoelectronic devices. Depending on the stacking patterns, either an n-type or a p-type Schottky contact is formed at the interface, which can be transformed under strain engineering and electric field.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Daniel J. Rizzo, Sara Shabani, Bjarke S. Jessen, Jin Zhang, Alexander S. McLeod, Carmen Rubio-Verdu, Francesco L. Ruta, Matthew Cothrine, Jiaqiang Yan, David G. Mandrus, Stephen E. Nagler, Angel Rubio, James C. Hone, Cory R. Dean, Abhay N. Pasupathy, D. N. Basov
Summary: The researchers successfully created nanometer-scale lateral p-n junctions using graphene/alpha-RuCl3 heterostructure near graphene nanobubbles. Through STM/STS and s-SNOM techniques, they investigated the electronic and optical responses of nanobubble p-n junctions, achieving p-n junctions with a width of around 3 nm and an electric field of approximately 10(8) V/m. The study also utilized ab initio density functional theory calculations to corroborate experimental data and provide insights into charge transfer mechanisms in 2D materials.
Article
Nanoscience & Nanotechnology
Xinjiang Zhang, Anping Huang, Zhisong Xiao, Mei Wang, Jing Zhang, Paul K. Chu
Summary: The transfer characteristics and switching mechanism of the steep-slope transistor composed of the graphene/Janus MoSSe heterostructure have been investigated. The gate voltage can tune the Schottky barrier height and tunneling width, resulting in ambipolar switching with two minima in the subthreshold swing slope. The device provides a solution and guidance for the future design of low-power, high-performance devices.
Article
Chemistry, Multidisciplinary
Can Zou, Zixuan Zhao, Mingjun Xu, Xingfu Wang, Qing Liu, Kai Chen, Longfei He, Fangliang Gao, Shuti Li
Summary: To address the issue of minority carrier storage time in bipolar transistors, a hot electron transistor (HET) has been proposed. This device offers high working speed and the ability to perform complex logic functions with just one component. A mixed-dimensional HET composed of GaN/AlN microwires, graphene (Gr), and Si has been demonstrated, which achieves high speed hot electrons by injecting electrons between GaN/AlN into graphene through F-N tunneling mechanism, allowing for ballistic transport and collection through low-barrier Si. The device exhibits a record DC gain of 16.2, collection efficiency close to the limit of 99.9% based on GHET, emitter current density of 68.7 A/cm2, high on/off current ratio of approximately 107, and wide current saturation range, making it suitable for potential applications as a power amplifier.
Article
Physics, Applied
D. Kaiser, Z. Tang, M. Kullmer, C. Neumann, A. Winter, R. Kahle, L. Georgi, T. Weimann, M. Siegmann, S. Grafe, A. Centeno, A. Zurutuza, A. Turchanin
Summary: The study reported a van der Waals heterostructure based on graphene and carbon nanomembrane for pH sensing, achieving high pH resolution and fast response. The developed device concept shows promising potential for engineering microscale pH sensors in biological and environmental sciences applications.
APPLIED PHYSICS REVIEWS
(2021)
Article
Chemistry, Multidisciplinary
Dmitry A. Mylnikov, Elena I. Titova, Mikhail A. Kashchenko, Ilya V. Safonov, Sergey S. Zhukov, Valentin A. Semkin, Kostya S. Novoselov, Denis A. Bandurin, Dmitry A. Svintsov
Summary: This study investigates the sub-terahertz photoconductivity of gapped bilayer graphene with electrically induced p-n junctions. The results show that these junctions have a strong positive contribution to resistance, temperature resistance coefficient, and photoresistivity at cryogenic temperatures.
Article
Chemistry, Physical
Ramin Ahmadi, Mohammad Taghi Ahmadi, Seyed Saeid Rahimian Koloor, Michal Petru
Summary: The research focuses on the application of twisted graphene as a new graphene structure in device technology. The study analyzes the geometry effect of twisted graphene on the operation of Schottky transistors, and explores the relationship between twist diameter and twist number.
Article
Crystallography
Seock-Hyeon Hong, Dong-Hyoup Seo, Hyunwook Song
Summary: This study demonstrates the fabrication and characterization of vertical molecular tunneling junctions based on graphene heterostructures. It employs statistical analysis to establish the representative junction properties and validates the electronic devices fabricated with graphene electrodes.
Article
Chemistry, Multidisciplinary
Kathrin Kuester, Zahra Hooshmand, Daniel Pablo Rosenblatt, Sebastian Koslowski, Duy Le, Ulrich Starke, Talat S. Rahman, Klaus Kern, Uta Schlickum
Summary: This study investigates the electronic and structural modifications of h-BN on Rh(111) by intercalating carbon to form graphene nanoflakes. Carbon atoms in Rh bulk crystals diffuse to the surface during h-BN growth, segregating there and altering the appearance of the Moire pattern, as well as modifying the electronic and chemical properties. The novel fabrication route demonstrates graphene nanoflakes located in a heterostack between Rh(111) and h-BN by segregating carbon impurities on the rhodium surface.
ADVANCED MATERIALS INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Bor-Wei Liang, Wen-Hao Chang, Hung-Yu Lin, Po-Chun Chen, Yi-Tang Zhang, Kristan Bryan Simbulan, Kai-Shin Li, Jyun-Hong Chen, Chieh-Hsiung Kuan, Yann-Wen Lan
Summary: The study demonstrates a vertical graphene-based hot-electron transistor operating in the radio frequency regime, showing high current density and gains, with the cutoff frequency tunable by varying the collector-base bias.
Article
Physics, Multidisciplinary
Fumiya Mukai, Kota Horii, Ryoya Ebisuoka, Kenji Watanabe, Takashi Taniguchi, Ryuta Yagi
Summary: The study focuses on the Moire superlattice of twisted h-BN/AB-stacked tetralayer graphene heterostructures, revealing that band gaps arise due to Fermi surface nesting at specific angles. The Moire superlattice of multilayer graphene exhibits features influenced by the anisotropic Fermi surface affected by the superlattice structure, with resistivity peaks showing a complex dependence on the perpendicular electric field.
COMMUNICATIONS PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Fuyou Liao, Zheng Zhou, Beom Jin Kim, Jiewei Chen, Jingli Wang, Tianqing Wan, Yue Zhou, Anh Tuan Hoang, Cong Wang, Jinfeng Kang, Jong-Hyun Ahn, Yang Chai
Summary: This study presents bioinspired vision sensors based on molybdenum disulfide phototransistors that mimic the adaptive behavior of human eyes. By introducing charge trap states, the photosensitivity of the devices can be dynamically modulated under different lighting conditions, providing highly localized and dynamic modulation of photosensitivity at the pixel level and creating an effective perception range of up to 199 dB.
NATURE ELECTRONICS
(2022)
Review
Materials Science, Multidisciplinary
Songfang Zhao, Jong-Hyun Ahn
Summary: Researchers have developed high-performance tactile sensors based on bioinspired structures/functions, natural biopolymers, and biomimetic strategies, inspired by the concepts and design principles evident in natural materials and structures. However, the main challenge lies in developing novel sensing mechanisms and device structures that are sufficiently sensitive and stretchable using bioinspired materials. In this review, we discuss recent advancements in this field, focusing on biomimetic approaches to producing tactile sensors with essential sensing capabilities and the development of bioinspired materials with desired electrical and mechanical properties. Additionally, we highlight the potential applications of these devices and discuss future directions for research.
MATERIALS SCIENCE & ENGINEERING R-REPORTS
(2022)
Article
Nanoscience & Nanotechnology
Sumin Hwangbo, Luhing Hu, Anh Tuan Hoang, Jae Yong Choi, Jong-Hyun Ahn
Summary: This paper presents a novel fabrication method for the integration of transition metal dichalcogenides with compound semiconductors, which is compatible with a batch microfabrication process. The authors demonstrate the synthesis of a thin film of molybdenum disulfide on a gallium-nitride-based epitaxial wafer, which is then used to form a thin film transistor array. This transistor array is subsequently integrated with micro-light-emitting-diode devices to create an active matrix micro-LED display. The authors also show a simple approach for obtaining red and green colors through the printing of quantum dots on a blue micro-LED, enabling the scalable fabrication of full-color micro-LED displays.
NATURE NANOTECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Zhangfu Chen, Woohyun Hwang, Minhyun Cho, Anh Tuan Hoang, Minju Kim, Dongwoo Kim, Dong Ha Kim, Young Duck Kim, Hyun Jae Kim, Jong-Hyun Ahn, Aloysius Soon, Heon-Jin Choi
Summary: This study reports on the growth of GeS microribbons via CVT, which exhibit low-symmetry orthorhombic structure and anisotropic optical and electronic properties. The GeS microribbons show photoluminescence and anisotropic absorption effects, making them suitable for photoelectronic transistors.
NPG ASIA MATERIALS
(2022)
Article
Multidisciplinary Sciences
Minpyo Kang, Hyerin Jeong, Sung-Won Park, Juyeong Hong, Hyeyeon Lee, Youngcheol Chae, Sunggu Yang, Jong-Hyun Ahn
Summary: This article introduces a wearable thermal patch with dual functions of continuous skin temperature sensing and thermotherapy for effective self-care treatment.
Article
Chemistry, Multidisciplinary
Zhangfu Chen, Anh Tuan Hoang, Woohyun Hwang, Dongjea Seo, Minhyun Cho, Young Duck Kim, Lianqiao Yang, Aloysius Soon, Jong-Hyun Ahn, Heon-Jin Choi
Summary: In this study, we report the growth of single crystalline GeS microribbons using the chemical vapor transport process. By using conductive atomic force microscopy, we demonstrate that the conductive behavior in the vertical direction is mainly affected by the Schottky barriers between GeS and both electrodes. We also find that the topographic and current heterogeneities are significantly different with and without illumination.
Article
Multidisciplinary Sciences
Dong Gue Roe, Dong Hae Ho, Yoon Young Choi, Young Jin Choi, Seongchan Kim, Sae Byeok Jo, Moon Sung Kang, Jong-Hyun Ahn, Jeong Ho Cho
Summary: With advances in robotic technology, the complexity of robot control has been increasing due to fundamental signal bottlenecks and limited expressible logic state of the von Neumann architecture. Here, we demonstrate coordinated movement by a fully parallel-processable synaptic array with reduced control complexity. The proposed synaptic control system provides considerable scope for the advancement of robotic control systems.
NATURE COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Kang Lib Kim, Sung Hwan Cho, Jae-Bok Lee, Gwangmook Kim, Kyuho Lee, Seung Won Lee, Han Sol Kang, Chanho Park, Jong-Hyun Ahn, Wooyoung Shim, Insung Bae, Cheolmin Park
Summary: This study presents transparent and flexible capacitive pressure sensors using a high-k ionic gel blended with an ionic liquid. The topological semicrystalline surface of the blend films enhances their sensitivity to pressure. With optically transparent and mechanically flexible graphene electrodes, a novel pressure sensor with a self-assembled crystalline topology is developed. It exhibits high sensitivity, rapid response times, and durable device operation, making it suitable for various wearable applications.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Review
Chemistry, Multidisciplinary
Yifei Luo, Mohammad Reza Abidian, Jong-Hyun Ahn, Deji Akinwande, Anne M. Andrews, Markus Antonietti, Zhenan Bao, Magnus Berggren, Christopher A. Berkey, Christopher John Bettinger, Jun Chen, Peng Chen, Wenlong Cheng, Xu Cheng, Seon-Jin Choi, Alex Chortos, Canan Dagdeviren, Reinhold H. Dauskardt, Chong-an Di, Michael D. Dickey, Xiangfeng Duan, Antonio Facchetti, Zhiyong Fan, Yin Fang, Jianyou Feng, Xue Feng, Huajian Gao, Wei Gao, Xiwen Gong, Chuan Fei Guo, Xiaojun Guo, Martin C. Hartel, Zihan He, John S. Ho, Youfan Hu, Qiyao Huang, Yu Huang, Fengwei Huo, Muhammad M. Hussain, Ali Javey, Unyong Jeong, Chen Jiang, Xingyu Jiang, Jiheong Kang, Daniil Karnaushenko, Ali Khademhosseini, Dae-Hyeong Kim, Il-Doo Kim, Dmitry Kireev, Lingxuan Kong, Chengkuo Lee, Nae-Eung Lee, Pooi See Lee, Tae-Woo Lee, Fengyu Li, Jinxing Li, Cuiyuan Liang, Chwee Teck Lim, Yuanjing Lin, Darren J. Lipomi, Jia Liu, Kai Liu, Nan Liu, Ren Liu, Yuxin Liu, Yuxuan Liu, Zhiyuan Liu, Zhuangjian Liu, Xian Jun Loh, Nanshu Lu, Zhisheng Lv, Shlomo Magdassi, George G. Malliaras, Naoji Matsuhisa, Arokia Nathan, Simiao Niu, Jieming Pan, Changhyun Pang, Qibing Pei, Huisheng Peng, Dianpeng Qi, Huaying Ren, John A. Rogers, Aaron Rowe, Oliver G. Schmidt, Tsuyoshi Sekitani, Dae-Gyo Seo, Guozhen Shen, Xing Sheng, Qiongfeng Shi, Takao Someya, Yanlin Song, Eleni Stavrinidou, Meng Su, Xuemei Sun, Kuniharu Takei, Xiao-Ming Tao, Benjamin C. K. Tee, Aaron Voon-Yew Thean, Tran Quang Trung, Changjin Wan, Huiliang Wang, Joseph Wang, Ming Wang, Sihong Wang, Ting Wang, Zhong Lin Wang, Paul S. Weiss, Hanqi Wen, Sheng Xu, Tailin Xu, Hongping Yan, Xuzhou Yan, Hui Yang, Le Yang, Shuaijian Yang, Lan Yin, Cunjiang Yu, Guihua Yu, Jing Yu, Shu-Hong Yu, Xinge Yu, Evgeny Zamburg, Haixia Zhang, Xiangyu Zhang, Xiaosheng Zhang, Xueji Zhang, Yihui Zhang, Yu Zhang, Siyuan Zhao, Xuanhe Zhao, Yuanjin Zheng, Yu-Qing Zheng, Zijian Zheng, Tao Zhou, Bowen Zhu, Ming Zhu, Rong Zhu, Yangzhi Zhu, Yong Zhu, Guijin Zou, Xiaodong Chen
Summary: Humans are increasingly relying on flexible sensors to address challenges and improve quality of life in the digital and big data era. However, the market adoption of flexible sensors is still limited despite advancements in research. In this paper, we identify the bottlenecks hindering the maturation of flexible sensors and propose potential solutions to expedite their deployment and commercialization.
Article
Chemistry, Multidisciplinary
Bangjie Shao, Tianqing Wan, Fuyou Liao, Beom Jin Kim, Jiewei Chen, Jianmiao Guo, Sijie Ma, Jong-Hyun Ahn, Yang Chai
Summary: This article introduces a method of encryption in the sensor, which achieves highly reliable encryption and authentication by binding the generated key with the image.
Article
Nanoscience & Nanotechnology
Jiewei Chen, Zheng Zhou, Beom Jin Kim, Yue Zhou, Zhaoqing Wang, Tianqing Wan, Jianmin Yan, Jinfeng Kang, Jong-Hyun Ahn, Yang Chai
Summary: Inspired by agile insects, researchers emulate graded neurons using optoelectronic devices to achieve bioinspired in-sensor motion perception with high recognition accuracy. This study is important for understanding efficient motion perception in insects and its application in artificial intelligence.
NATURE NANOTECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Tanmoy Das, Sukhyeong Youn, Jae Eun Seo, Eunyeong Yang, Jiwon Chang
Summary: Achieving effective polarity control of n- and p-type transistors is critical for integrating 2D materials into CMOS logic circuits. By utilizing an aluminum oxide passivation layer, a complete carrier polarity conversion from p- to n-type was achieved, resulting in precisely tuned n-type behavior.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Larionette P. L. Mawlong, Anh Tuan Hoang, Jyothi Chintalapalli, Seunghyeon Ji, Kihyun Lee, Kwanpyo Kim, Jong-Hyun Ahn
Summary: This study introduces a new method for synthesizing large-area, high-quality two-dimensional transition metal dichalcogenides, such as MoS2. The method improves the performance of photodetectors and reduces sulfur vacancy defects in the film, which significantly affects material quality.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Jeongsik Lim, Sangwon Lee, Jejung Kim, Jeonghoon Hong, Sooho Lim, Kyungtae Kim, Jeongwoo Kim, Sungchil Yang, Sunggu Yang, Jong-Hyun Ahn
Summary: Various techniques, such as electrocorticography (ECoG), have been studied for the diagnosis and treatment of epilepsy. This study developed a high-density, flexible electrode array with graphene/Au/graphene, which successfully detected brain signals and suppressed epileptic discharges and behavior in rats. Simultaneous recording and neurostimulation in awake animals could have a fundamental impact on the treatment of medically intractable epilepsy.
NPG ASIA MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Meili Xia, Jianwen Liu, Beom Jin Kim, Yongju Gao, Yunlong Zhou, Yongjing Zhang, Duxia Cao, Songfang Zhao, Yang Li, Jong-Hyun Ahn
Summary: In this study, a skin-compliant dry electrode with excellent performance and water/motion interference resistance was developed. The electrode exhibited low impedance, high stretchability, and stability, thanks to the kirigami structure and unique encapsulation. Compared to traditional dry or gel electrodes, this electrode can effectively capture high-quality biopotential signals and facilitate human-machine interactions under various conditions.