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Song Q, Zhang Y, Chen Q, Wu S, Yan X, He K, Gao G, Chen Q, Wang S. Site-Selective Synthesis of Bilayer Graphene on Cu Substrates Using Titanium as a Carbon Diffusion Barrier. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 39011562 DOI: 10.1021/acsami.4c04521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
Chemical vapor deposition (CVD) is a widely used method for graphene synthesis, but it struggles to produce large-area uniform bilayer graphene (BLG). This study introduces a novel approach to meet the demands of large-scale integrated circuit applications, challenging the conventional reliance on uniform BLG over extensive areas. We developed a unique method involving the direct growth of bilayer graphene arrays (BLGA) on Cu foil substrates using patterned titanium (Ti) as a diffusion barrier. The use of the Ti layer can effectively control carbon atom diffusion through the Cu foil without altering the growth conditions or compromising the graphene quality, thereby showcasing its versatility. The approach allows for targeted BLG growth and achieved a yield of 100% for a 10 × 10 BLG units array. Then a 10 × 10 BLG memristor array was fabricated, and a yield of 96% was achieved. The performances of these devices show good uniformity, evidenced by the set voltages concentrated around 4 V, and a high resistance state (HRS) to low resistance state (LRS) ratio predominantly around 107, reflecting the spatial uniformity of the prepared BLGA. This study provides insight into the BLG growth mechanism and opens new possibilities for BLG-based electronics.
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Affiliation(s)
- Qiyang Song
- MOE Key Laboratory of Fundamental Physical Quantities Measurement & Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Youwei Zhang
- MOE Key Laboratory of Fundamental Physical Quantities Measurement & Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
- Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen 518057, China
| | - Qiao Chen
- MOE Key Laboratory of Fundamental Physical Quantities Measurement & Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Su Wu
- MOE Key Laboratory of Fundamental Physical Quantities Measurement & Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xin Yan
- Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi'an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi'an, Shaanxi 710119, China
| | - Kai He
- Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi'an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi'an, Shaanxi 710119, China
| | - Guilong Gao
- Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, Xi'an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi'an, Shaanxi 710119, China
| | - Qiao Chen
- Gemmological Institute, China University of Geosciences, Wuhan 430074, China
| | - Shun Wang
- MOE Key Laboratory of Fundamental Physical Quantities Measurement & Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
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Yan X, Zheng Z, Sangwan VK, Qian JH, Wang X, Liu SE, Watanabe K, Taniguchi T, Xu SY, Jarillo-Herrero P, Ma Q, Hersam MC. Moiré synaptic transistor with room-temperature neuromorphic functionality. Nature 2023; 624:551-556. [PMID: 38123805 DOI: 10.1038/s41586-023-06791-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 10/26/2023] [Indexed: 12/23/2023]
Abstract
Moiré quantum materials host exotic electronic phenomena through enhanced internal Coulomb interactions in twisted two-dimensional heterostructures1-4. When combined with the exceptionally high electrostatic control in atomically thin materials5-8, moiré heterostructures have the potential to enable next-generation electronic devices with unprecedented functionality. However, despite extensive exploration, moiré electronic phenomena have thus far been limited to impractically low cryogenic temperatures9-14, thus precluding real-world applications of moiré quantum materials. Here we report the experimental realization and room-temperature operation of a low-power (20 pW) moiré synaptic transistor based on an asymmetric bilayer graphene/hexagonal boron nitride moiré heterostructure. The asymmetric moiré potential gives rise to robust electronic ratchet states, which enable hysteretic, non-volatile injection of charge carriers that control the conductance of the device. The asymmetric gating in dual-gated moiré heterostructures realizes diverse biorealistic neuromorphic functionalities, such as reconfigurable synaptic responses, spatiotemporal-based tempotrons and Bienenstock-Cooper-Munro input-specific adaptation. In this manner, the moiré synaptic transistor enables efficient compute-in-memory designs and edge hardware accelerators for artificial intelligence and machine learning.
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Affiliation(s)
- Xiaodong Yan
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Zhiren Zheng
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Vinod K Sangwan
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Justin H Qian
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Xueqiao Wang
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Stephanie E Liu
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Material Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Su-Yang Xu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | | | - Qiong Ma
- Department of Physics, Boston College, Chestnut Hill, MA, USA.
- CIFAR Azrieli Global Scholars Program, CIFAR, Toronto, Ontario, Canada.
| | - Mark C Hersam
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA.
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, USA.
- Department of Chemistry, Northwestern University, Evanston, IL, USA.
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Li Q, Liu T, Li Y, Li F, Zhao Y, Huang S. A Wrinkling and Etching-Assisted Regrowth Strategy for Large-Area Bilayer Graphene Preparation on Cu. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2059. [PMID: 37513070 PMCID: PMC10385747 DOI: 10.3390/nano13142059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/05/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023]
Abstract
Bilayer graphene is a contender of interest for functional electronic applications because of its variable band gap due to interlayer interactions. Graphene growth on Cu is self-limiting, thus despite the fact that chemical vapor deposition (CVD) has made substantial strides in the production of monolayer and single-crystal graphene on Cu substrates, the direct synthesizing of high-quality, large-area bilayer graphene remains an enormous challenge. In order to tackle this issue, we present a simple technique using typical CVD graphene growth followed by a repetitive wrinkling-etching-regrowth procedure. The key element of our approach is the rapid cooling process that causes high-density wrinkles to form in the monolayer area rather than the bilayer area. Next, wrinkled sites are selectively etched with hydrogen, exposing a significant portion of the active Cu surface, and leaving the remaining bilayer areas, which enhance the nucleation and growth of the second graphene layer. A fully covered graphene with 78 ± 2.8% bilayer coverage and a bilayer transmittance of 95.6% at room temperature can be achieved by modifying the process settings. Bilayer graphene samples are examined using optical microscopy (OM), scanning electron microscopy (SEM), Raman spectroscopy, and an atomic force microscope (AFM) during this process. The outcomes of our research are beneficial in clarifying the growth processes and future commercial applications of bilayer graphene.
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Affiliation(s)
- Qiongyu Li
- School of Electronic, Electrical Engineering and Physics, Fujian University of Technology, Fuzhou 350118, China
| | - Tongzhi Liu
- School of Electronic, Electrical Engineering and Physics, Fujian University of Technology, Fuzhou 350118, China
| | - You Li
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Fang Li
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yanshuai Zhao
- School of Electronic, Electrical Engineering and Physics, Fujian University of Technology, Fuzhou 350118, China
| | - Shihao Huang
- School of Electronic, Electrical Engineering and Physics, Fujian University of Technology, Fuzhou 350118, China
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