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Yang NJ, Guo WT, Yang H, Huang Z, Zhang JM. Topological phases, local magnetic moments, and spin polarization triggered by C 558-line defects in armchair graphene nanoribbons. Phys Chem Chem Phys 2024; 26:17075-17082. [PMID: 38842020 DOI: 10.1039/d4cp00585f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
The topological and magnetic properties induced by topological defects in graphene have attracted attention. Here, we study a novel topological defect structure for graphene nanoribbons interspersed with C558-line defects along the armchair boundary, which possesses topological properties and is tritopic. Using strain engineering to regulate the magnitude of hopping at defects, the position of the energy level can be easily changed to achieve a topological phase transition. We also discuss the local magnetic moment and the ferromagnetic ground state in the context of line defects. This leads to spin polarization of the whole system. Finally, when C558 graphene nanoribbons are controlled by a nonlocal exchange magnetic field, spin-polarized quantum conductivity occurs near the Fermi level. Consequently, spin filtering can be achieved by varying the incident energy of the electrons. Our results provide new insights into realizing topological and spin electronics in low-dimensional quantum devices.
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Affiliation(s)
- Ning-Jing Yang
- Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou 350117, China.
- Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering, Fuzhou, 350117, China
| | - Wen-Ti Guo
- Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou 350117, China.
- Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering, Fuzhou, 350117, China
| | - Hai Yang
- School of Physics Science and Technology, Kunming University, Kunming 650214, China
| | - Zhigao Huang
- Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou 350117, China.
- Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering, Fuzhou, 350117, China
| | - Jian-Min Zhang
- Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou 350117, China.
- Fujian Provincial Collaborative Innovation Center for Advanced High-Field Superconducting Materials and Engineering, Fuzhou, 350117, China
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2
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Yu M, Hu Z, Zhou J, Lu Y, Guo W, Zhang Z. Retrieving Grain Boundaries in 2D Materials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2205593. [PMID: 36461686 DOI: 10.1002/smll.202205593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/13/2022] [Indexed: 06/17/2023]
Abstract
The coalescence of randomly distributed grains with different crystallographic orientations can result in pervasive grain boundaries (GBs) in 2D materials during their chemical synthesis. GBs not only are the inherent structural imperfection that causes influential impacts on structures and properties of 2D materials, but also have emerged as a platform for exploring unusual physics and functionalities stemming from dramatic changes in local atomic organization and even chemical makeup. Here, recent advances in studying the formation mechanism, atomic structures, and functional properties of GBs in a range of 2D materials are reviewed. By analyzing the growth mechanism and the competition between far-field strain and local chemical energies of dislocation cores, a complete understanding of the rich GB morphologies as well as their dependence on lattice misorientations and chemical compositions is presented. Mechanical, electronic, and chemical properties tied to GBs in different materials are then discussed, towards raising the concept of using GBs as a robust atomic-scale scaffold for realizing tailored functionalities, such as magnetism, luminescence, and catalysis. Finally, the future opportunities in retrieving GBs for making functional devices and the major challenges in the controlled formation of GB structures for designed applications are commented.
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Affiliation(s)
- Maolin Yu
- Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Zhili Hu
- Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Jingzhuo Zhou
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Yang Lu
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Wanlin Guo
- Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Zhuhua Zhang
- Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
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3
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Yang SJ, Choi MY, Kim CJ. Engineering Grain Boundaries in Two-Dimensional Electronic Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203425. [PMID: 35777352 DOI: 10.1002/adma.202203425] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Engineering the boundary structures in 2D materials provides an unprecedented opportunity to program the physical properties of the materials with extensive tunability and realize innovative devices with advanced functionalities. However, structural engineering technology is still in its infancy, and creating artificial boundary structures with high reproducibility remains difficult. In this review, various emergent properties of 2D materials with different grain boundaries, and the current techniques to control the structures, are introduced. The remaining challenges for scalable and reproducible structure control and the outlook on the future directions of the related techniques are also discussed.
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Affiliation(s)
- Seong-Jun Yang
- Center for Epitaxial van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang, Gyeongbuk, 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Min-Yeong Choi
- Center for Epitaxial van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang, Gyeongbuk, 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Cheol-Joo Kim
- Center for Epitaxial van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang, Gyeongbuk, 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, 37673, Republic of Korea
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Bhatt MD, Kim H, Kim G. Various defects in graphene: a review. RSC Adv 2022; 12:21520-21547. [PMID: 35975063 PMCID: PMC9347212 DOI: 10.1039/d2ra01436j] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 07/19/2022] [Indexed: 11/23/2022] Open
Abstract
Pristine graphene has been considered one of the most promising materials because of its excellent physical and chemical properties. However, various defects in graphene produced during synthesis or fabrication hinder its performance for applications such as electronic devices, transparent electrodes, and spintronic devices. Due to its intrinsic bandgap and nonmagnetic nature, it cannot be used in nanoelectronics or spintronics. Intrinsic and extrinsic defects are ultimately introduced to tailor electronic and magnetic properties and take advantage of their hidden potential. This article emphasizes the current advancement of intrinsic and extrinsic defects in graphene for potential applications. We also discuss the limitations and outlook for such defects in graphene.
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Affiliation(s)
| | - Heeju Kim
- Hybrid Materials Center, Sejong University Seoul 05006 Korea
- Department of Physics and Astronomy, Sejong University Seoul 05006 Korea
| | - Gunn Kim
- Hybrid Materials Center, Sejong University Seoul 05006 Korea
- Department of Physics and Astronomy, Sejong University Seoul 05006 Korea
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5
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Kim J, Han JW, Yamada Y. Heptagons in the Basal Plane of Graphene Nanoflakes Analyzed by Simulated X-ray Photoelectron Spectroscopy. ACS OMEGA 2021; 6:2389-2395. [PMID: 33521477 PMCID: PMC7841947 DOI: 10.1021/acsomega.0c05717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 12/31/2020] [Indexed: 06/12/2023]
Abstract
The performance of graphene-based electronic devices depends critically on the existence of topological defects such as heptagons. Identifying heptagons at the atomic scale is important to completely understand the electronic properties of these materials. In this study, we report an atomic-scale analysis of graphene nanoflakes with two to eight isolated or connected heptagons, using simulated C 1s X-ray photoelectron spectroscopy (XPS) to estimate the XPS profiles depending on the density and the position of the heptagons. The introduction of up to 24% of isolated heptagons shifted the peak position toward high binding energies (284.0 to 284.3 eV), whereas the introduction of up to 39% of connected heptagons shifted the calculated peak position toward low binding energies (284.0 to 283.5 eV). The presence of heptagons also influenced the full width at half-maximum (FWHM). The introduction of 24% of isolated heptagons increased the FWHMs from 1.25 to 1.50 eV. However, the introduction of connected heptagons did not increase the FWHMs above 1.40 eV. The FWHMs increased to 1.40 eV for 19% of connected heptagons, but did not increase further as the percentage of connected heptagons increased to 39%. Based on the calculated results, the XPS profiles of graphene nanoflakes containing heptagons with different densities and positions can be obtained. Our precise identification of heptagons in graphene nanoflakes by XPS lays the groundwork for the analysis of graphene.
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Affiliation(s)
- Jungpil Kim
- Carbon
Material Application Research Group, Korea
Institute of Industrial Technology, 222 Palbok-ro, Deokjin-gu, Jeonju 54853, Republic
of Korea
| | - Jang-Woo Han
- Department
of Mechanical Design Engineering, Kumoh
National Institute of Technology, 61 Daehak-ro, Gumi 39177, Republic of Korea
| | - Yasuhiro Yamada
- Graduate
School of Engineering, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan
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Abstract
Grain boundaries (GBs) are a kind of lattice imperfection widely existing in two-dimensional materials, playing a critical role in materials' properties and device performance. Related key issues in this area have drawn much attention and are still under intense investigation. These issues include the characterization of GBs at different length scales, the dynamic formation of GBs during the synthesis, the manipulation of the configuration and density of GBs for specific material functionality, and the understanding of structure-property relationships and device applications. This review will provide a general introduction of progress in this field. Several techniques for characterizing GBs, such as direct imaging by high-resolution transmission electron microscopy, visualization techniques of GBs by optical microscopy, plasmon propagation, or second harmonic generation, are presented. To understand the dynamic formation process of GBs during the growth, a general geometric approach and theoretical consideration are reviewed. Moreover, strategies controlling the density of GBs for GB-free materials or materials with tunable GB patterns are summarized, and the effects of GBs on materials' properties are discussed. Finally, challenges and outlook are provided.
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Affiliation(s)
- Wenqian Yao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, P.R. China
- Sino-Danish Center for Education and Research, Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Bin Wu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, P.R. China
| | - Yunqi Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, P.R. China
- Sino-Danish Center for Education and Research, Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
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7
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Nguyen VH, Charlier JC. Aharonov-Bohm interferences in polycrystalline graphene. NANOSCALE ADVANCES 2020; 2:256-263. [PMID: 36133971 PMCID: PMC9419533 DOI: 10.1039/c9na00542k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/13/2019] [Indexed: 06/14/2023]
Abstract
Aharonov-Bohm (AB) interferences in the quantum Hall regime can be achieved, provided that electrons are able to transmit between two edge channels in nanostructures. Pioneering approaches include quantum point contacts in 2DEG systems, bipolar graphene p-n junctions, and magnetic field heterostructures. In this work, defect scattering is proposed as an alternative mechanism to achieve AB interferences in polycrystalline graphene. Indeed, due to such scattering, the extended defects across the sample can act as tunneling paths connecting quantum Hall edge channels. Consequently, strong AB oscillations in the conductance are predicted in polycrystalline graphene systems with two parallel grain boundaries. In addition, this general approach is demonstrated to be applicable to nano-systems containing two graphene barriers with functional impurities and perspectively, can also be extended to similar systems of 2D materials beyond graphene.
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Affiliation(s)
- V Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain (UCLouvain) Chemin des étoiles 8 B-1348 Louvain-la-Neuve Belgium
| | - J-C Charlier
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain (UCLouvain) Chemin des étoiles 8 B-1348 Louvain-la-Neuve Belgium
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8
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Ludwig J, Mehta AN, Mascaro M, Celano U, Chiappe D, Bender H, Vandervorst W, Paredis K. Effects of buried grain boundaries in multilayer MoS 2. NANOTECHNOLOGY 2019; 30:285705. [PMID: 30921772 DOI: 10.1088/1361-6528/ab142f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Two-dimensional transition metal dichalcogenides have been the focus of intense research for their potential application in novel electronic and optoelectronic devices. However, growth of large area two-dimensional transition metal dichalcogenides invariably leads to the formation of grain boundaries that can significantly degrade electrical transport by forming large electrostatic barriers. It is therefore critical to understand their effect on the electronic properties of two-dimensional semiconductors. Using MoS2 as an example material, we are able to probe grain boundaries in top and buried layers using conductive atomic force microscopy. We find that the electrical radius of the grain boundary extends approximately 2 nm from the core into the pristine material. The presence of grain boundaries affects electrical conductivity not just within its own layer, but also in the surrounding layers. Therefore, electrical grain size is always smaller than the physical size, and decreases with increasing thickness of the MoS2. These results signify that the number of layers in synthetically grown 2D materials must ideally be limited for device applications.
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Affiliation(s)
- Jonathan Ludwig
- IMEC, Leuven, Belgium. Department of Physics and Astronomy, University of Leuven, Leuven, Belgium
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9
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Xiao Y, Zhou M, Zeng M, Fu L. Atomic-Scale Structural Modification of 2D Materials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1801501. [PMID: 30886793 PMCID: PMC6402411 DOI: 10.1002/advs.201801501] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 10/20/2018] [Indexed: 05/02/2023]
Abstract
2D materials have attracted much attention since the discovery of graphene in 2004. Due to their unique electrical, optical, and magnetic properties, they have potential for various applications such as electronics and optoelectronics. Owing to thermal motion and lattice growth kinetics, different atomic-scale structures (ASSs) can originate from natural or intentional regulation of 2D material atomic configurations. The transformations of ASSs can result in the variation of the charge density, electronic density of state and lattice symmetry so that the property tuning of 2D materials can be achieved and the functional devices can be constructed. Here, several kinds of ASSs of 2D materials are introduced, including grain boundaries, atomic defects, edge structures, and stacking arrangements. The design strategies of these structures are also summarized, especially for atomic defects and edge structures. Moreover, toward multifunctional integration of applications, the modulation of electrical, optical, and magnetic properties based on atomic-scale structural modification are presented. Finally, challenges and outlooks are featured in the aspects of controllable structure design and accurate property tuning for 2D materials with ASSs. This work may promote research on the atomic-scale structural modification of 2D materials toward functional applications.
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Affiliation(s)
- Yao Xiao
- The Institute for Advanced Studies (IAS)Wuhan UniversityWuhan430072P. R. China
| | - Mengyue Zhou
- College of Chemistry and Molecular SciencesWuhan UniversityWuhan430072P. R. China
| | - Mengqi Zeng
- College of Chemistry and Molecular SciencesWuhan UniversityWuhan430072P. R. China
| | - Lei Fu
- The Institute for Advanced Studies (IAS)Wuhan UniversityWuhan430072P. R. China
- College of Chemistry and Molecular SciencesWuhan UniversityWuhan430072P. R. China
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10
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Deng B, Liu Z, Peng H. Toward Mass Production of CVD Graphene Films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1800996. [PMID: 30277604 DOI: 10.1002/adma.201800996] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 06/14/2018] [Indexed: 05/09/2023]
Abstract
Chemical vapor deposition (CVD) is considered to be an efficient method for fabricating large-area and high-quality graphene films due to its excellent controllability and scalability. Great efforts have been made to control the growth of graphene to achieve large domain sizes, uniform layers, fast growth, and low synthesis temperatures. Some attempts have been made by both the scientific community and startup companies to mass produce graphene films; however, there is a large difference in the quality of graphene synthesized on a laboratory scale and an industrial scale. Here, recent progress toward the mass production of CVD graphene films is summarized, including the manufacturing process, equipment, and critical process parameters. Moreover, the large-scale homogeneity of graphene films and fast characterization methods are also discussed, which are crucial for quality control in mass production.
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Affiliation(s)
- Bing Deng
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Zhongfan Liu
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
- Beijing Graphene Institute (BGI), Beijing, 100094, China
| | - Hailin Peng
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
- Beijing Graphene Institute (BGI), Beijing, 100094, China
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11
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Dong J, Zhang L, Ding F. Kinetics of Graphene and 2D Materials Growth. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1801583. [PMID: 30318816 DOI: 10.1002/adma.201801583] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 07/06/2018] [Indexed: 06/08/2023]
Abstract
During the last 10 years, remarkable achievements on the chemical vapor deposition (CVD) growth of 2D materials have been made, but the understanding of the underlying mechanisms is still relatively limited. Here, the current progress on the understanding of the growth kinetics of 2D materials, especially for their CVD synthesis, is reviewed. In order to present a complete picture of 2D materials' growth kinetics, the following factors are discussed: i) two types of growth modes, namely attachment-limited growth and diffusion-limited growth; ii) the etching of 2D materials, which offers an additional degree of freedom for growth control; iii) a number of experimental factors in graphene CVD synthesis, such as structure of the substrate, pressure of hydrogen or oxygen, temperature, etc., which are found to have profound effects on the growth kinetics; iv) double-layer and few-layer 2D materials' growth, which has distinct features different from the growth of single-layer 2D materials; and v) the growth of polycrystalline 2D materials by the coalescence of a few single crystalline domains. Finally, the current challenges and opportunities in future 2D materials' synthesis are summarized.
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Affiliation(s)
- Jichen Dong
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Leining Zhang
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Feng Ding
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
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12
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Hong M, Zhou X, Gao N, Jiang S, Xie C, Zhao L, Gao Y, Zhang Z, Yang P, Shi Y, Zhang Q, Liu Z, Zhao J, Zhang Y. Identifying the Non-Identical Outermost Selenium Atoms and Invariable Band Gaps across the Grain Boundary of Anisotropic Rhenium Diselenide. ACS NANO 2018; 12:10095-10103. [PMID: 30226744 DOI: 10.1021/acsnano.8b04872] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Rhenium diselenide (ReSe2) is a unique transition-metal dichalcogenide (TMDC) possessing distorted 1T structure with a triclinic symmetry, strong in-plane anisotropy, and promising applications in optoelectronics and energy-related fields. So far, the structural and physical properties of ReSe2 are mainly uncovered by transmission electron microscopy and spectroscopy characterizations. Herein, by combining scanning tunneling microscopy and spectroscopy (STM and STS) with first-principles calculations, we accomplish the on-site atomic-scale identification of the top four non-identical Se atoms in a unit cell of the anisotropic monolayer ReSe2 on the Au substrate. According to STS and photoluminescence results, we also determine the quasiparticle and optical band gaps as well as the exciton binding energy of monolayer ReSe2. In particular, we detect a perfect lattice coherence and an invariable band gap across the mirror-symmetric grain boundaries in monolayer and bilayer ReSe2, which considerably differ from the traditional isotropic TMDCs featured with defect structures and additional states inside the band gap. Such essential findings should deepen our understanding of the intrinsic properties of two-dimensional anisotropic materials and provide fundamental references for their applications in related fields.
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Affiliation(s)
| | | | - Nan Gao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams , Dalian University of Technology, Ministry of Education , Dalian 116024 , China
| | | | | | | | | | | | | | | | | | | | - Jijun Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams , Dalian University of Technology, Ministry of Education , Dalian 116024 , China
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13
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Tuček J, Błoński P, Ugolotti J, Swain AK, Enoki T, Zbořil R. Emerging chemical strategies for imprinting magnetism in graphene and related 2D materials for spintronic and biomedical applications. Chem Soc Rev 2018; 47:3899-3990. [PMID: 29578212 DOI: 10.1039/c7cs00288b] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Graphene, a single two-dimensional sheet of carbon atoms with an arrangement mimicking the honeycomb hexagonal architecture, has captured immense interest of the scientific community since its isolation in 2004. Besides its extraordinarily high electrical conductivity and surface area, graphene shows a long spin lifetime and limited hyperfine interactions, which favors its potential exploitation in spintronic and biomedical applications, provided it can be made magnetic. However, pristine graphene is diamagnetic in nature due to solely sp2 hybridization. Thus, various attempts have been proposed to imprint magnetic features into graphene. The present review focuses on a systematic classification and physicochemical description of approaches leading to equip graphene with magnetic properties. These include introduction of point and line defects into graphene lattices, spatial confinement and edge engineering, doping of graphene lattice with foreign atoms, and sp3 functionalization. Each magnetism-imprinting strategy is discussed in detail including identification of roles of various internal and external parameters in the induced magnetic regimes, with assessment of their robustness. Moreover, emergence of magnetism in graphene analogues and related 2D materials such as transition metal dichalcogenides, metal halides, metal dinitrides, MXenes, hexagonal boron nitride, and other organic compounds is also reviewed. Since the magnetic features of graphene can be readily masked by the presence of magnetic residues from synthesis itself or sample handling, the issue of magnetic impurities and correct data interpretations is also addressed. Finally, current problems and challenges in magnetism of graphene and related 2D materials and future potential applications are also highlighted.
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Affiliation(s)
- Jiří Tuček
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
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14
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Dechamps S, Nguyen VH, Charlier JC. Ab initio quantum transport in polycrystalline graphene. NANOSCALE 2018; 10:7759-7768. [PMID: 29658557 DOI: 10.1039/c8nr00289d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Synthesis techniques such as chemical vapor deposition yield graphene in polycrystalline flakes where single-crystal domains are separated by grain boundaries (GBs) of irregular shape. These structural defects are mostly made up of pentagon-heptagon pairs and represent an important source of scattering, thus strongly affecting electronic mobilities in polycrystalline graphene (PG). In the present article, first-principles simulations are performed to explore charge transport through a GB in PG using the Landauer-Büttiker formalism implemented within the Green's function approach. In ideal GB configurations, electronic transport is found to depend on their topology as already suggested in the literature. However, more realistic GBs constructed out of various carbon rings and with more complex periodicities are also considered, possibly inducing leakage currents. Finally, additional realistic disorder such as vacancies, a larger inter-connectivity region and out-of plane buckling is investigated. For specific energies, charge redistribution effects related to the detailed GB topology are found to substantially alter the transmissions. Altogether, the transport gap is predicted to be inversely proportional to the smallest significant periodic pattern and nearly independent of the interface configuration.
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Affiliation(s)
- Samuel Dechamps
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium.
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15
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Dong J, Zhang L, Zhang K, Ding F. How graphene crosses a grain boundary on the catalyst surface during chemical vapour deposition growth. NANOSCALE 2018; 10:6878-6883. [PMID: 29633768 DOI: 10.1039/c7nr06840a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The chemical vapour deposition (CVD) growth of graphene is normally an epitaxial process, where the atomic structure of the adlayer should copy the texture of the substrate. However, it has been widely observed that single crystalline graphene grown on metal foil may cross a grain boundary (GB) of the substrate without forming any line defect, a necessary condition to change its crystalline orientation and maintain the structure registry with the substrate on the other side of the GB. Here, we present a comprehensive theoretical study on graphene growth behavior on polycrystalline metal substrates. Our density functional theory (DFT) calculations reveal that for graphene growth on most metal surfaces, the binding energy difference between the epitaxial and non-epitaxial graphene on the substrate is not large enough to compensate for the formation energy of a GB in graphene and therefore, during the CVD process, the growing graphene can pass through a GB on the metal surface without changing its crystalline orientation. Hence, graphene CVD growth cannot be strictly regarded as an epitaxial process; this conclusion is further verified by atomic simulations. The present study shows that the growth of graphene on a metal catalyst surface should be regarded rather as a quasi-epitaxial process, where a graphene domain is aligned only on the single crystalline metal facet on which it nucleates, but this structural registry with the metal substrate may be lost when the graphene crosses a GB on the metal surface.
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Affiliation(s)
- Jichen Dong
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea.
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16
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Wang Y, Liu Z. Spontaneous rolling-up and assembly of graphene designed by using defects. NANOSCALE 2018; 10:6487-6495. [PMID: 29569671 DOI: 10.1039/c8nr00286j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The inverse Stone-Wales defect is a typical defect in graphene, which causes local bumps and local deformation in graphene sheets. Our molecular dynamics simulations show that the spontaneous rolling up of graphene sheets can be induced by orderly distributed inverse Stone-Wales defect bumps, when defective graphene is cut into small strips. This spontaneous process is mainly dominated by the defect density and tailored graphene size. When the tailored length is longer than the upper threshold length, graphene sews up as a curly one-dimensional structure: heart-shaped nanotube. For medium length graphene (the length is in between the lower threshold value and upper threshold value), the results reveal that graphene finally curls into a completely or incompletely stitched nanotube similar to a cylindrical shell. This spontaneous process is produced by a high-frequency damped vibration accompanied by elastic and viscoelastic deformation in defective graphene. Thus, the properties of vibration are further investigated for graphene that has the tailored length shorter than the lower threshold length. This kind of graphene gradually forms a curved nanoribbon rather than a nanotube. It is also found that the bending rigidity of defective graphene is larger than that of pristine graphene.
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Affiliation(s)
- Ying Wang
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Zishun Liu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an 710049, China.
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17
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Jiang S, Hong M, Wei W, Zhao L, Zhang N, Zhang Z, Yang P, Gao N, Zhou X, Xie C, Shi J, Huan Y, Tong L, Zhao J, Zhang Q, Fu Q, Zhang Y. Direct synthesis and in situ characterization of monolayer parallelogrammic rhenium diselenide on gold foil. Commun Chem 2018. [DOI: 10.1038/s42004-018-0010-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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18
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Li Y, Wei A, Ye H, Yao H. Mechanical and thermal properties of grain boundary in a planar heterostructure of graphene and hexagonal boron nitride. NANOSCALE 2018; 10:3497-3508. [PMID: 29404556 DOI: 10.1039/c7nr07306b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this study, the mechanical properties of grain boundaries (GBs) in planar heterostructures of graphene and hexagonal boron nitride (h-BN) were studied using the molecular dynamics method in combination with the density functional theory and classical disclination theory. The hybrid interface between graphene and h-BN grains was optimally matched by a non-bisector GB composed of pentagon-heptagon defects arranged in a periodic manner. GB was found to be a vulnerable spot to initiate failure under uniaxial tension; moreover, the tensile strength was found to anomalously increase with an increase in the mismatch angle between graphene and h-BN grains, i.e., the density of pentagon-heptagon defects along the GBs. The disclination theory was successfully adopted to predict the stress field caused by lattice mismatch at the GB. Comparison between stress contours of GBs with different mismatch angles demonstrates that the arrangement of 5-7 disclinations along the GB is crucial to the strength, and the stress concentration at the GB decreases with an increase in disclination density; this results in an anomalous increase of strength with an increase in the mismatch angle of grains. Moreover, the thermal transfer efficiency of the hybrid GB was revealed to be dependent not only on the mismatch angle of grains but also on the direction of the thermal flux. Thermal transfer efficiency from graphene to h-BN is higher than that from h-BN to graphene. Detailed analyses for the phonon density of states (PDOS) of GB atoms were carried out for the mismatch angle-dependence of interfacial conductance. Our results provide useful insights for the application of two-dimensional polycrystalline heterostructures in next-generation electronic nanodevices.
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Affiliation(s)
- Yinfeng Li
- Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering (State Key Laboratory of Ocean Engineering), Shanghai Jiao Tong University, Shanghai 200240, China.
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19
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Ma J, Li X, Yin L, Wang W, Sun Q, Yang Y, Zhang P, Nie J, Xiong C, Dou R. Mapping electronic states of triple anti-parallel and symmetric zigzag grain boundaries of graphene on highly oriented pyrolytic graphite. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2017.12.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Thermal boundary resistance between the polycrystalline graphene and the amorphous SiO2 substrate. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.07.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Nguyen VH, Dechamps S, Dollfus P, Charlier JC. Valley Filtering and Electronic Optics Using Polycrystalline Graphene. PHYSICAL REVIEW LETTERS 2016; 117:247702. [PMID: 28009222 DOI: 10.1103/physrevlett.117.247702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Indexed: 06/06/2023]
Abstract
In this Letter, both the manipulation of valley-polarized currents and the optical-like behaviors of Dirac fermions are theoretically explored in polycrystalline graphene. When strain is applied, the misorientation between two graphene domains separated by a grain boundary can result in a mismatch of their electronic structures. Such a discrepancy manifests itself in a strong breaking of the inversion symmetry, leading to perfect valley polarization in a wide range of transmission directions. In addition, these graphene domains act as different media for electron waves, offering the possibility to modulate and obtain negative refraction indexes.
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Affiliation(s)
- V Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - S Dechamps
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - P Dollfus
- Centre for Nanoscience and Nanotechnology, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - J-C Charlier
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
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22
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Dong J, Wang H, Peng H, Liu Z, Zhang K, Ding F. Formation mechanism of overlapping grain boundaries in graphene chemical vapor deposition growth. Chem Sci 2016; 8:2209-2214. [PMID: 28507676 PMCID: PMC5408562 DOI: 10.1039/c6sc04535a] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 11/23/2016] [Indexed: 11/21/2022] Open
Abstract
The formation mechanisms of two different types of grain boundaries (GBs), the weakly bound overlapping GB and the covalent bound GB, during graphene domain coalescence are revealed by both theoretical modeling and experimental observations.
The formation of grain boundaries (GBs) in graphene films is both fundamentally interesting and practically important for many applications. A GB in graphene is known as a linear defect and is formed during the coalescence of two single crystalline graphene domains. The covalent binding between domains is broadly known as the mechanism of GB formation during graphene chemical vapor deposition (CVD) growth. Here, we demonstrate another GB formation mechanism, where two graphene domains are connected by weak van der Waals interactions between overlapping graphene layers. The formation mechanism of the overlapping GBs (OLGBs) is systematically explored theoretically and the proposed conditions for forming OLGBs are validated by experimental observations. This discovery leads to a deep understanding of the mechanism of graphene CVD growth and reveals potential means for graphene quality control in CVD synthesis.
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Affiliation(s)
- Jichen Dong
- Department of Mechanical and Biomedical Engineering , City University of Hong Kong , 83 Tat Chee Avenue , Kowloon , Hong Kong , China . .,Institute of Textiles and Clothing , Hong Kong Polytechnic University , Kowloon , Hong Kong , China .
| | - Huan Wang
- College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China
| | - Hailin Peng
- College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China
| | - Zhongfan Liu
- College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China
| | - Kaili Zhang
- Department of Mechanical and Biomedical Engineering , City University of Hong Kong , 83 Tat Chee Avenue , Kowloon , Hong Kong , China .
| | - Feng Ding
- Institute of Textiles and Clothing , Hong Kong Polytechnic University , Kowloon , Hong Kong , China .
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23
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Li Z, Wu Y, Nan J, Tang X, Zhang J, Yang B. Wrinkled single-layer graphenes fabricated by silicon nanopillar arrays. NANOTECHNOLOGY 2016; 27:475304. [PMID: 27782006 DOI: 10.1088/0957-4484/27/47/475304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The degree of crumpling affects the optoelectronic properties of graphene, which are very important for the performance of graphene-based devices and materials. In this article, we report an approach to tune the formation of wrinkles on single-layer graphene (SLG) by silicon nanopillar (SNP) arrays. By using gold nanoparticles as an etching mask, SNP arrays with different heights could be prepared by tuning the duration of etching. The formation of wrinkles on these SNP arrays was studied systematically. We found that thermal treatment could lead to a wrapping behavior of graphene around SNP arrays, which was accompanied by the emergence of many more wrinkles. Controllable wettability, conductivity and transmittance were demonstrated. This ability to tune wrinkles using SNP arrays can be employed to engineer the fabrication of graphene-related devices and other optoelectronic applications.
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Affiliation(s)
- Zibo Li
- State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, People's Republic of China
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24
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Gong C, He K, Chen Q, Robertson AW, Warner JH. In Situ High Temperature Atomic Level Studies of Large Closed Grain Boundary Loops in Graphene. ACS NANO 2016; 10:9165-9173. [PMID: 27661200 DOI: 10.1021/acsnano.6b04959] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We use an in situ heating holder within an aberration corrected transmission electron microscope (AC-TEM) to study the structure and dynamics of large closed grain boundary (GB) loops in graphene at the atomic level. Temperatures up to 800 °C are used to accelerate dynamic evolution of the defect clusters, increasing bond rotation and atomic addition/loss. Our results show that the large closed GB loops relax under electron beam irradiation into several isolated dislocations far apart from each other. Line defects composed of several adjacent excess-atom clusters can be found during the reconfiguration process. Dislocation ejection from the closed GB loops are seen in real time and are shown to help the reduction in loop size. These results show detailed information about the stability and behavior of large GB loops in 2D materials that have importance in the high temperature processing of these materials.
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Affiliation(s)
- Chuncheng Gong
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Kuang He
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Qu Chen
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Alex W Robertson
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Jamie H Warner
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
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25
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Gong C, He K, Lee GD, Chen Q, Robertson AW, Yoon E, Hong S, Warner JH. In Situ Atomic Level Dynamics of Heterogeneous Nucleation and Growth of Graphene from Inorganic Nanoparticle Seeds. ACS NANO 2016; 10:9397-9410. [PMID: 27643716 DOI: 10.1021/acsnano.6b04356] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An in situ heating holder inside an aberration-corrected transmission electron microscope (AC-TEM) is used to investigate the real-time atomic level dynamics associated with heterogeneous nucleation and growth of graphene from Au nanoparticle seeds. Heating monolayer graphene to an elevated temperature of 800 °C removes the majority of amorphous carbon adsorbates and leaves a clean surface. The aggregation of Au impurity atoms into nanoparticle clusters that are bound to the surface of monolayer graphene causes nucleation of secondary graphene layers from carbon feedstock present within the microscope chamber. This enables the in situ study of heterogeneous nucleation and growth of graphene at the atomic level. We show that the growth mechanism consists of alternating C cluster attachment and indentation filling to maintain a uniform growth front of lowest energy. Back-folding of the graphene growth front is observed, followed by a process that involves flipping back and attaching to the surrounding region. We show how the highly polycrystalline graphene seed evolves with time into a higher order crystalline structure using a combination of AC-TEM and tight-binding molecular dynamics (TBMD) simulations. This helps understand the detailed lowest-energy step-by-step pathways associated with grain boundaries (GB) migration and crystallization processes. We find the motion of the GB is discontinuous and mediated by both bond rotation and atom evaporation, supported by density functional theory calculations and TBMD. These results provide insights into the formation of crystalline seed domains that are generated during bottom-up graphene synthesis.
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Affiliation(s)
- Chuncheng Gong
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Kuang He
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Gun-Do Lee
- Department of Materials Science and Engineering, Seoul National University , Seoul 151-742, Korea
| | - Qu Chen
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Alex W Robertson
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
| | - Euijoon Yoon
- Department of Materials Science and Engineering, Seoul National University , Seoul 151-742, Korea
| | - Suklyun Hong
- Department of Physics and Graphene Research Institute, Sejong University , Seoul 143-747, Korea
| | - Jamie H Warner
- Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom
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26
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Wang C, Schouteden K, Wu QH, Li Z, Jiang J, Van Haesendonck C. Atomic resolution of nitrogen-doped graphene on Cu foils. NANOTECHNOLOGY 2016; 27:365702. [PMID: 27479275 DOI: 10.1088/0957-4484/27/36/365702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Atomic-level substitutional doping can significantly tune the electronic properties of graphene. Using low-temperature scanning tunneling microscopy and spectroscopy, the atomic-scale crystalline structure of graphene grown on polycrystalline Cu, the distribution of nitrogen dopants and their effect on the electronic properties of graphene were investigated. Both the graphene sheet growth and nitrogen doping were performed using microwave plasma-enhanced chemical vapor deposition. The results indicated that the nitrogen dopants preferentially sit at the grain boundaries of the graphene sheets and confirmed that plasma treatment is a potential method to incorporate foreign atoms into the graphene lattice to tailor the graphene's electronic properties.
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Affiliation(s)
- Chundong Wang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China. Laboratory of Solid-State Physics and Magnetism, Department of Physics and Astronomy, KU Leuven, B-3001 Leuven, Belgium
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27
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Huang YL, Ding Z, Zhang W, Chang YH, Shi Y, Li LJ, Song Z, Zheng YJ, Chi D, Quek SY, Wee ATS. Gap States at Low-Angle Grain Boundaries in Monolayer Tungsten Diselenide. NANO LETTERS 2016; 16:3682-3688. [PMID: 27140667 DOI: 10.1021/acs.nanolett.6b00888] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Two-dimensional (2D) transition metal dichalcogenides (TMDs) have revealed many novel properties of interest to future device applications. In particular, the presence of grain boundaries (GBs) can significantly influence the material properties of 2D TMDs. However, direct characterization of the electronic properties of the GB defects at the atomic scale remains extremely challenging. In this study, we employ scanning tunneling microscopy and spectroscopy to investigate the atomic and electronic structure of low-angle GBs of monolayer tungsten diselenide (WSe2) with misorientation angles of 3-6°. Butterfly features are observed along the GBs, with the periodicity depending on the misorientation angle. Density functional theory calculations show that these butterfly features correspond to gap states that arise in tetragonal dislocation cores and extend to distorted six-membered rings around the dislocation core. Understanding the nature of GB defects and their influence on transport and other device properties highlights the importance of defect engineering in future 2D device fabrication.
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Affiliation(s)
- Yu Li Huang
- Institute of Materials Research & Engineering (IMRE), A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore
- Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore
| | - Zijing Ding
- SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University , Shenzhen 518060, China
- Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore
| | - Wenjing Zhang
- SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University , Shenzhen 518060, China
| | - Yung-Huang Chang
- Department of Electrophysics, National Chiao Tung University , Hsinchu 300, Taiwan
| | - Yumeng Shi
- Physical Sciences and Engineering, King Abdullah University of Science and Technology , Thuwal 23955-6900, Saudi Arabia
| | - Lain-Jong Li
- Physical Sciences and Engineering, King Abdullah University of Science and Technology , Thuwal 23955-6900, Saudi Arabia
| | - Zhibo Song
- Institute of Materials Research & Engineering (IMRE), A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore
- Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore
| | - Yu Jie Zheng
- Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore
| | - Dongzhi Chi
- Institute of Materials Research & Engineering (IMRE), A*STAR (Agency for Science, Technology and Research) , 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore
| | - Su Ying Quek
- Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore
- Centre for Advanced 2D Materials, National University of Singapore , Block S14, Level 6, 6 Science Drive 2, Singapore 117546, Singapore
| | - Andrew T S Wee
- Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551, Singapore
- Centre for Advanced 2D Materials, National University of Singapore , Block S14, Level 6, 6 Science Drive 2, Singapore 117546, Singapore
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28
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Hung Nguyen V, Hoang TX, Dollfus P, Charlier JC. Transport properties through graphene grain boundaries: strain effects versus lattice symmetry. NANOSCALE 2016; 8:11658-11673. [PMID: 27218828 DOI: 10.1039/c6nr01359g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
As most materials available at the macroscopic scale, graphene samples usually appear in a polycrystalline form and thus contain grain boundaries. In the present work, the effect of uniaxial strain on the electronic transport properties through graphene grain boundaries is investigated using atomistic simulations. A systematic picture of transport properties with respect to the strain and lattice symmetry of graphene domains on both sides of the boundary is provided. In particular, it is shown that strain engineering can be used to open a finite transport gap in all graphene systems where the two domains are arranged in different orientations. This gap value is found to depend on the strain magnitude, on the strain direction and on the lattice symmetry of graphene domains. By choosing appropriately the strain direction, a large transport gap of a few hundred meV can be achieved when applying a small strain of only a few percents. For a specific class of graphene grain boundary systems, strain engineering can also be used to reduce the scattering on defects and thus to significantly enhance the conductance. With a large strain-induced gap, these graphene heterostructures are proposed to be promising candidates for highly sensitive strain sensors, flexible electronic devices and p-n junctions with non-linear I-V characteristics.
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Affiliation(s)
- V Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium. and Institut d'Electronique Fondamentale, CNRS, Univ. Paris Sud, Université Paris-Saclay, 91405 Orsay, France and Center for Computational Physics, Institute of Physics, Vietnam Academy of Science and Technology, P.O. Box 429 Bo Ho, 10000 Hanoi, Vietnam
| | - Trinh X Hoang
- Center for Computational Physics, Institute of Physics, Vietnam Academy of Science and Technology, P.O. Box 429 Bo Ho, 10000 Hanoi, Vietnam
| | - P Dollfus
- Institut d'Electronique Fondamentale, CNRS, Univ. Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - J-C Charlier
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium.
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29
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Implication of mesoporous 3-D graphene skeleton platform based on interconnected framework architecture in constructing electro-conductive flexible nanocomposites. Macromol Res 2016. [DOI: 10.1007/s13233-016-4013-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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30
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Shekhawat A, Ophus C, Ritchie RO. A generalized Read–Shockley model and large scale simulations for the energy and structure of graphene grain boundaries. RSC Adv 2016. [DOI: 10.1039/c6ra07584c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The grain boundary (GB) energy is a quantity of fundamental importance for understanding several key properties of graphene.
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Affiliation(s)
- Ashivni Shekhawat
- Department of Materials Science and Engineering
- University of California Berkeley
- USA
- Miller Institute for Basic Research in Science
- University of California Berkeley
| | - Colin Ophus
- National Center for Electron Microscopy
- Molecular Foundry
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
| | - Robert O. Ritchie
- Department of Materials Science and Engineering
- University of California Berkeley
- USA
- Materials Sciences Division
- Lawrence Berkeley National Laboratory
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31
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Zhang X, Xu Z, Yuan Q, Xin J, Ding F. The favourable large misorientation angle grain boundaries in graphene. NANOSCALE 2015; 7:20082-20088. [PMID: 26568448 DOI: 10.1039/c5nr04960a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A grain boundary (GB) in graphene is a linear defect between two specifically oriented graphene edges, whose title angles are denoted as θ1 and θ2, respectively. Here we present a systematic theoretical study on the structure and stability of GBs in graphene as a function of the misorientation angle, Φ = (θ1-θ2) and the GB orientation in multi-crystalline graphene, which is denoted by Θ = (θ1 + θ2). It is surprising that although the number of disorders of the GB, i.e., the pentagon-heptagon pairs (5|7s), reaches the maximum at Φ∼ 30°, the GB formation energy versus the Φ curve reaches a local minimum. The subsequent M-shape of the Efvs. the Φ curve is due to the strong cancellation of the local strains around 5|7 pairs by the "head-to-tail" formation. This study successfully explains many previously observed experimental puzzles, such as the multimodal distribution of GBs and the abundance of GB misorientation angles of ∼30°. Besides, this study also showed that the formation energy of GBs is less sensitive to Θ, although the twin boundaries are slightly more stable than others.
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Affiliation(s)
- Xiuyun Zhang
- Institute of Textile and clothing, Hong Kong Polytechnic University, Hong Kong, China.
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32
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Zou X, Yakobson BI. Metallic High-Angle Grain Boundaries in Monolayer Polycrystalline WS2. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:4503-4507. [PMID: 26101136 DOI: 10.1002/smll.201500811] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/25/2015] [Indexed: 06/04/2023]
Affiliation(s)
- Xiaolong Zou
- Department of Materials Science and NanoEngineering, Department of Chemistry, The Smalley Institute for Nanoscale Science and Technology, Rice University, Houston, TX, 77005, USA
| | - Boris I Yakobson
- Department of Materials Science and NanoEngineering, Department of Chemistry, The Smalley Institute for Nanoscale Science and Technology, Rice University, Houston, TX, 77005, USA
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33
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Li Q, Zou X, Liu M, Sun J, Gao Y, Qi Y, Zhou X, Yakobson BI, Zhang Y, Liu Z. Grain Boundary Structures and Electronic Properties of Hexagonal Boron Nitride on Cu(111). NANO LETTERS 2015; 15:5804-10. [PMID: 26244850 DOI: 10.1021/acs.nanolett.5b01852] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Grain boundaries (GBs) of hexagonal boron nitride (h-BN) grown on Cu(111) were investigated by scanning tunneling microscopy/spectroscopy (STM/STS). The first experimental evidence of the GBs composed of square-octagon pairs (4|8 GBs) was given, together with those containing pentagon-heptagon pairs (5|7 GBs). Two types of GBs were found to exhibit significantly different electronic properties, where the band gap of the 5|7 GB was dramatically decreased as compared with that of the 4|8 GB, consistent with our obtained result from density functional theory (DFT) calculations. Moreover, the present work may provide a possibility of tuning the inert electronic property of h-BN via grain boundary engineering.
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Affiliation(s)
- Qiucheng Li
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | | | - Mengxi Liu
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | - Jingyu Sun
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | - Yabo Gao
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | - Yue Qi
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | - Xiebo Zhou
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, People's Republic of China
| | | | - Yanfeng Zhang
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, People's Republic of China
| | - Zhongfan Liu
- Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
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Nguyen VL, Lee YH. Towards Wafer-Scale Monocrystalline Graphene Growth and Characterization. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:3512-28. [PMID: 25903119 DOI: 10.1002/smll.201500147] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 03/02/2015] [Indexed: 05/08/2023]
Abstract
Since its discovery in 2004, graphene has boosted numerous fundamental sciences and technological applications due to its massless Dirac particle-like linear band dispersion, that causes unprecedented physical properties. Among the various methods for synthesizing graphene, chemical vapor deposition is the most suitable approach for scalable production on a wafer scale, which is a critical step for practical applications. Graphene grain boundaries (GGBs), consisting of nonhexagonal carbon rings and therefore modulating the properties of graphene films, are inevitably formed via the merging of adjacent graphene domains with different orientations. Large-area monocrystalline graphene synthesis without forming GGBs has been challenging, let alone observing such boundaries. Here, an up-to-date review is presented of how to grow wafer-scale monocrystalline graphene without GGBs. One approach is to make single domain sizes as large as possible by reducing or passivating the number of nucleation sites. Another approach is to align graphene domains in identical orientations, and then merge them atomically. The recently developed methods for observing graphene orientation and GGBs both at the atomic and macro-scales are also presented. Finally, perspectives for future research in graphene growth are discussed.
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Affiliation(s)
- Van Luan Nguyen
- IBS Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 440-746, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 440-746, Republic of Korea
| | - Young Hee Lee
- IBS Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 440-746, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 440-746, Republic of Korea
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35
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Flexible free-standing composite films having 3D continuous structures of hollow graphene ellipsoids. Macromol Res 2015. [DOI: 10.1007/s13233-015-3072-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ma C, Sun H, Du H, Wang J, Zhao A, Li Q, Wang B, Hou JG. Structural and electronic properties of an ordered grain boundary formed by separated (1,0) dislocations in graphene. NANOSCALE 2015; 7:3055-3059. [PMID: 25603956 DOI: 10.1039/c4nr06789d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present an investigation of the structural and electronic properties of an ordered grain boundary (GB) formed by separated pentagon-heptagon pairs in single-layer graphene/SiO2 using scanning tunneling microscopy/spectroscopy (STM/STS), coupled with density functional theory (DFT) calculations. It is observed that the pentagon-heptagon pairs, i.e., (1,0) dislocations, form a periodic quasi-one-dimensional chain. The (1,0) dislocations are separated by 8 transverse rows of carbon rings, with a period of ∼2.1 nm. The protruded feature of each dislocation shown in the STM images reflects its out-of-plane buckling structure, which is supported by the DFT simulations. The STS spectra recorded along the small-angle GB show obvious differential-conductance peaks, the positions of which qualitatively accord with the van Hove singularities from the DFT calculations.
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Affiliation(s)
- Chuanxu Ma
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
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37
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Skowron ST, Lebedeva IV, Popov AM, Bichoutskaia E. Energetics of atomic scale structure changes in graphene. Chem Soc Rev 2015; 44:3143-76. [DOI: 10.1039/c4cs00499j] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
An overview of theoretical and experimental studies concerned with energetics of atomic scale structure changes in graphene, including thermally activated and electron irradiation-induced processes.
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Affiliation(s)
| | - Irina V. Lebedeva
- Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre
- Departamento de Física de Materiales
- Universidad del Pais Vasco UPV/EHU
- San Sebastian E-20018
- Spain
| | - Andrey M. Popov
- Institute for Spectroscopy of Russian Academy of Sciences
- Moscow 142190
- Russia
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38
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Rasool HI, Ophus C, Zhang Z, Crommie MF, Yakobson BI, Zettl A. Conserved atomic bonding sequences and strain organization of graphene grain boundaries. NANO LETTERS 2014; 14:7057-7063. [PMID: 25375022 DOI: 10.1021/nl503450r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The bulk properties of polycrystalline materials are directly influenced by the atomic structure at the grain boundaries that join neighboring crystallites. In this work, we show that graphene grain boundaries are comprised of structural building blocks of conserved atomic bonding sequences using aberration corrected high-resolution transmission electron microscopy. These sequences appear as stretches of identically arranged periodic or aperiodic regions of dislocations. Atomic scale strain and lattice rotation of these interfaces is derived by mapping the exact positions of every carbon atom at the boundary with ultrahigh precision. Strain fields are organized into local tensile and compressive dipoles in both periodic and aperiodic dislocation regions. Using molecular dynamics tension simulations, we find that experimental grain boundary structures maintain strengths that are comparable to idealized periodic boundaries despite the presence of local aperiodic dislocation sequences.
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Affiliation(s)
- Haider I Rasool
- Department of Physics and Center of Integrated Nanomechanical Systems (COINS), University of California at Berkeley , Berkeley, California 94720, United States
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