1
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Dechamps S, Nguyen VH, Charlier JC. Lateral junctions of transition metal dichalcogenides as ballistic channels for straintronic applications. Nanotechnology 2024; 35:175201. [PMID: 38211329 DOI: 10.1088/1361-6528/ad1d78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 01/11/2024] [Indexed: 01/13/2024]
Abstract
In the context of advanced nanoelectronics, two-dimensional semiconductors such as transition metal dichalcogenides (TMDs) are gaining considerable interest due to their ultimate thinness, clean surface and high carrier mobility. The engineering prospects offered by those materials are further enlarged by the recent realization of atomically sharp TMD-based lateral junctions, whose electronic properties are governed by strain effects arising from the constituents lattice mismatch. Although most theoretical studies considered only misfit strain, first-principles simulations are employed here to investigate the transport properties under external deformation of a three-terminal device constructed from a MoS2/WSe2/MoS2junction. Large modulation of the current is reported owing to the change in band offset, illustrating the importance of strain on the p-n junction characteristics. The device operation is demonstrated for both local and global deformations, even for ultra-short channels, suggesting potential applications for ultra-thin body straintronics.
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Affiliation(s)
- Samuel Dechamps
- Université Grenoble Alpes, CEA, IRIG-MEM, 38000 Grenoble, France
| | - Viet-Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - Jean-Christophe 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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2
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Cardia R, Dardenne N, Mula G, Pinna E, Rignanese GM, Charlier JC, Cappellini G. First-Principles Investigation of the Optical Properties of Eumelanin Protomolecules. J Phys Chem A 2023; 127:10797-10806. [PMID: 38109190 DOI: 10.1021/acs.jpca.3c04898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Using first-principles calculations, we investigate the absorption spectra (in the near-infrared, visible, and first UV range) of the two most probable eumelanin tetrameric molecules exhibiting either a linear open-chain or a cyclic porphyrine-like configuration. In order to simulate a realistic molecular system, an implicit solvent model is used in our calculations to mimic the effect of the solvated environment around the eumelanin molecule. Although the presence of solvent is found not to significantly affect the absorption pattern of both molecules, the onset of the spectra are shifted toward higher energies, especially for the linear tetramer. Interestingly, the absorption spectra and optical onsets of the two molecules differ significantly both in a vacuum and in ethanol. However, the two predicted spectra do not allow us to definitely discriminate between the two configurations when comparing the theoretical predictions with the available experimental spectrum. In addition, a mix of the two eumelanin configurations (close to fifty-fifty) leads to a maximum overlap between theoretical and experimental spectra. Consequently, this theoretical research shows that deeper insight can be gained using beyond DFT techniques on the real form of eumelanin protomolecules present in living systems as well as on their possible use in hybrid solar cells.
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Affiliation(s)
- Roberto Cardia
- Department of Physics, Università degli Studi di Cagliari, Cittadella Universitaria I-09042 Monserrato, Cagliari, Italy
| | - Nicolas Dardenne
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Guido Mula
- Department of Physics, Università degli Studi di Cagliari, Cittadella Universitaria I-09042 Monserrato, Cagliari, Italy
| | - Elisa Pinna
- Department of Physics, Università degli Studi di Cagliari, Cittadella Universitaria I-09042 Monserrato, Cagliari, Italy
| | - Gian-Marco Rignanese
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
- European Theoretical Spectroscopy Facility (ETSF)
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
- European Theoretical Spectroscopy Facility (ETSF)
| | - Giancarlo Cappellini
- Department of Physics, Università degli Studi di Cagliari, Cittadella Universitaria I-09042 Monserrato, Cagliari, Italy
- European Theoretical Spectroscopy Facility (ETSF)
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3
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Arrighi E, Nguyen VH, Di Luca M, Maffione G, Hong Y, Farrar L, Watanabe K, Taniguchi T, Mailly D, Charlier JC, Ribeiro-Palau R. Non-identical moiré twins in bilayer graphene. Nat Commun 2023; 14:8178. [PMID: 38081818 PMCID: PMC10713781 DOI: 10.1038/s41467-023-43965-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 11/24/2023] [Indexed: 02/09/2024] Open
Abstract
The superlattice obtained by aligning a monolayer graphene and boron nitride (BN) inherits from the hexagonal lattice a sixty degrees periodicity with the layer alignment. It implies that, in principle, the properties of the heterostructure must be identical for 0° and 60° of layer alignment. Here, we demonstrate, using dynamically rotatable van der Waals heterostructures, that the moiré superlattice formed in a bilayer graphene/BN has different electronic properties at 0° and 60° of alignment. Although the existence of these non-identical moiré twins is explained by different relaxation of the atomic structures for each alignment, the origin of the observed valley Hall effect remains to be explained. A simple Berry curvature argument is not sufficient to explain the 120° periodicity of this observation. Our results highlight the complexity of the interplay between mechanical and electronic properties in moiré structures and the importance of taking into account atomic structure relaxation to understand their electronic properties.
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Affiliation(s)
- Everton Arrighi
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120, Palaiseau, France
| | - Viet-Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348, Louvain-la-Neuve, Belgium
| | - Mario Di Luca
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120, Palaiseau, France
| | - Gaia Maffione
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120, Palaiseau, France
| | - Yuanzhuo Hong
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120, Palaiseau, France
| | - Liam Farrar
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120, Palaiseau, France
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - Dominique Mailly
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120, Palaiseau, France
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348, Louvain-la-Neuve, Belgium
| | - Rebeca Ribeiro-Palau
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120, Palaiseau, France.
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4
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Canetta A, Gonzalez-Munoz S, Nguyen VH, Agarwal K, de Crombrugghe de Picquendaele P, Hong Y, Mohapatra S, Watanabe K, Taniguchi T, Nysten B, Hackens B, Ribeiro-Palau R, Charlier JC, Kolosov OV, Spièce J, Gehring P. Quantifying the local mechanical properties of twisted double bilayer graphene. Nanoscale 2023; 15:8134-8140. [PMID: 36974920 DOI: 10.1039/d3nr00388d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Nanomechanical measurements of minimally twisted van der Waals materials remained elusive despite their fundamental importance for device realisation. Here, we use Ultrasonic Force Microscopy (UFM) to locally quantify the variation of out-of-plane Young's modulus in minimally twisted double bilayer graphene (TDBG). We reveal a softening of the Young's modulus by 7% and 17% along single and double domain walls, respectively. Our experimental results are confirmed by force-field relaxation models. This study highlights the strong tunability of nanomechanical properties in engineered twisted materials, and paves the way for future applications of designer 2D nanomechanical systems.
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Affiliation(s)
- Alessandra Canetta
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium.
| | | | - Viet-Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium.
| | | | | | - Yuanzhuo Hong
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120 Palaiseau, France
| | - Sambit Mohapatra
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120 Palaiseau, France
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Namiki 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Namiki 305-0044, Japan
| | - Bernard Nysten
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium.
| | - Benoît Hackens
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium.
| | - Rebeca Ribeiro-Palau
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies (C2N), 91120 Palaiseau, France
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium.
| | | | - Jean Spièce
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium.
| | - Pascal Gehring
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium.
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Zatko V, Dubois SMM, Godel F, Galbiati M, Peiro J, Sander A, Carretero C, Vecchiola A, Collin S, Bouzehouane K, Servet B, Petroff F, Charlier JC, Martin MB, Dlubak B, Seneor P. Almost Perfect Spin Filtering in Graphene-Based Magnetic Tunnel Junctions. ACS Nano 2022; 16:14007-14016. [PMID: 36068013 PMCID: PMC9527810 DOI: 10.1021/acsnano.2c03625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
We report on large spin-filtering effects in epitaxial graphene-based spin valves, strongly enhanced in our specific multilayer case. Our results were obtained by the effective association of chemical vapor deposited (CVD) multilayer graphene with a high quality epitaxial Ni(111) ferromagnetic spin source. We highlight that the Ni(111) spin source electrode crystallinity and metallic state are preserved and stabilized by multilayer graphene CVD growth. Complete nanometric spin valve junctions are fabricated using a local probe indentation process, and spin properties are extracted from the graphene-protected ferromagnetic electrode through the use of a reference Al2O3/Co spin analyzer. Strikingly, spin-transport measurements in these structures give rise to large negative tunnel magneto-resistance TMR = -160%, pointing to a particularly large spin polarization for the Ni(111)/Gr interface PNi/Gr, evaluated up to -98%. We then discuss an emerging physical picture of graphene-ferromagnet systems, sustained both by experimental data and ab initio calculations, intimately combining efficient spin filtering effects arising (i) from the bulk band structure of the graphene layers purifying the extracted spin direction, (ii) from the hybridization effects modulating the amplitude of spin polarized scattering states over the first few graphene layers at the interface, and (iii) from the epitaxial interfacial matching of the graphene layers with the spin-polarized Ni surface selecting well-defined spin polarized channels. Importantly, these main spin selection effects are shown to be either cooperating or competing, explaining why our transport results were not observed before. Overall, this study unveils a path to harness the full potential of low Resitance.Area (RA) graphene interfaces in efficient spin-based devices.
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Affiliation(s)
- Victor Zatko
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Simon M.-M. Dubois
- Institute
of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Florian Godel
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Marta Galbiati
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Julian Peiro
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Anke Sander
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Cécile Carretero
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Aymeric Vecchiola
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Sophie Collin
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Karim Bouzehouane
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Bernard Servet
- Thales
Research and Technology, 1 avenue Augustin Fresnel, 91767 Palaiseau, France
| | - Frédéric Petroff
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Jean-Christophe Charlier
- Institute
of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Marie-Blandine Martin
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Bruno Dlubak
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
| | - Pierre Seneor
- Unité
Mixte de Physique, CNRS, Thales, Université
Paris-Saclay, 91767 Palaiseau, France
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6
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Gadelha AC, Nguyen VH, Neto EGS, Santana F, Raschke MB, Lamparski M, Meunier V, Charlier JC, Jorio A. Electron-Phonon Coupling in a Magic-Angle Twisted-Bilayer Graphene Device from Gate-Dependent Raman Spectroscopy and Atomistic Modeling. Nano Lett 2022; 22:6069-6074. [PMID: 35878122 DOI: 10.1021/acs.nanolett.2c00905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The importance of phonons in the strong correlation phenomena observed in twisted-bilayer graphene (TBG) at the so-called magic-angle is under debate. Here we apply gate-dependent micro-Raman spectroscopy to monitor the G band line width in TBG devices of twist angles θ = 0° (Bernal), ∼1.1° (magic-angle), and ∼7° (large-angle). The results show a broad and p-/n-asymmetric doping behavior at the magic angle, in clear contrast to the behavior observed in twist angles above and below this point. Atomistic modeling reproduces the experimental observations in close connection with the joint density of electronic states in the electron-phonon scattering process, revealing how the unique electronic structure of magic-angle TBGs influences the electron-phonon coupling and, consequently, the G band line width. Overall, the value of the G band line width in magic-angle TBG is larger when compared to that of the other samples, in qualitative agreement with our calculations.
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Affiliation(s)
- Andreij C Gadelha
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
- Department of Physics, and JILA, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Viet-Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain (UCLouvain), Louvain-la-Neuve 1348, Belgium
| | - Eliel G S Neto
- Physics Institute, Universidade Federal da Bahia, Salvador, Bahia 40170-115 Brazil
| | - Fabiano Santana
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Markus B Raschke
- Department of Physics, and JILA, University of Colorado at Boulder, Boulder, Colorado 80309, United States
| | - Michael Lamparski
- Department of Physics, Applied Physics, and Astronomy, Jonsson Rowland Science Center, Troy, New York 12180-3590, United States
| | - Vincent Meunier
- Department of Physics, Applied Physics, and Astronomy, Jonsson Rowland Science Center, Troy, New York 12180-3590, United States
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain (UCLouvain), Louvain-la-Neuve 1348, Belgium
| | - Ado Jorio
- Physics Department, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil
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7
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Çınar M, Antidormi A, Nguyen VH, Kovtun A, Lara-Avila S, Liscio A, Charlier JC, Roche S, Sevinçli H. Toward Optimized Charge Transport in Multilayer Reduced Graphene Oxides. Nano Lett 2022; 22:2202-2208. [PMID: 35230103 PMCID: PMC8949764 DOI: 10.1021/acs.nanolett.1c03883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/22/2022] [Indexed: 06/14/2023]
Abstract
In the context of graphene-based composite applications, a complete understanding of charge conduction in multilayer reduced graphene oxides (rGO) is highly desirable. However, these rGO compounds are characterized by multiple and different sources of disorder depending on the chemical method used for their synthesis. Most importantly, the precise role of interlayer interaction in promoting or jeopardizing electronic flow remains unclear. Here, thanks to the development of a multiscale computational approach combining first-principles calculations with large-scale transport simulations, the transport scaling laws in multilayer rGO are unraveled, explaining why diffusion worsens with increasing film thickness. In contrast, contacted films are found to exhibit an opposite trend when the mean free path becomes shorter than the channel length, since conduction becomes predominantly driven by interlayer hopping. These predictions are favorably compared with experimental data and open a road toward the optimization of graphene-based composites with improved electrical conduction.
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Affiliation(s)
- Mustafa
Neşet Çınar
- Department
of Materials Science and Engineering, Izmir
Institute of Technology, 35430 Urla, Izmir, Turkey
| | - Aleandro Antidormi
- Catalan
Institute of Nanoscience and Nanotechnology, CSIC and The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra, Barcelona, Spain
| | - Viet-Hung Nguyen
- Institute
of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Alessandro Kovtun
- Consiglio
Nazionale delle Ricerche, Istituto per la
Sintesi Organica e la Fotoreattivitá, (CNR-ISOF), via Gobetti 101, 40129 Bologna, Italy
| | - Samuel Lara-Avila
- Department
of Microtechnology and Nanoscience, Chalmers
University of Technology, Kemivägen 9, 41296 Gothenburg, Sweden
| | - Andrea Liscio
- Consiglio
Nazionale delle Ricerche, Istituto per la
Microelettronica e Microsistemi, Roma Unit (CNR-IMM), via del fosso del cavaliere 100, 00133 Rome, Italy
| | - Jean-Christophe Charlier
- Institute
of Condensed Matter and Nanosciences, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Stephan Roche
- Catalan
Institute of Nanoscience and Nanotechnology, CSIC and The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra, Barcelona, Spain
- ICREA−Institució
Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| | - Hâldun Sevinçli
- Department
of Materials Science and Engineering, Izmir
Institute of Technology, 35430 Urla, Izmir, Turkey
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8
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Romito D, Fresta E, Cavinato LM, Kählig H, Amenitsch H, Caputo L, Chen Y, Samorì P, Charlier JC, Costa R, Bonifazi D. Supramolecular Chalcogen‐Bonded Semiconducting Nanoribbons at work in Lighting Devices. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202202137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Deborah Romito
- University of Vienna Faculty of Chemistry: Universitat Wien Fakultat fur Chemie Organic Chemistry Währinger Straße 38 1090 Vienna AUSTRIA
| | - Elisa Fresta
- Technical University Munich: Technische Universitat Munchen Chair of Biogenic Functional Materials Schulgasse 22 94315 Straubing GERMANY
| | - Luca Maria Cavinato
- Technical University of Munich: Technische Universitat Munchen Chair of Biogenic Functional Materials Schulgasse 22 94315 Straubing GERMANY
| | - Hanspeter Kählig
- University of Vienna Faculty of Chemistry: Universitat Wien Fakultat fur Chemie Organic Chemistry Währinger Straße 38 1090 vienna AUSTRIA
| | - Heinz Amenitsch
- Graz University of Technology: Technische Universitat Graz Institute for Inorganic Chemistry Stremayergasse 9/V 8010 Graz AUSTRIA
| | - Laura Caputo
- UCLouvain Saint-Louis Bruxelles: Universite Saint-Louis - Bruxelles Institute of Condensed Matter and Nanosciences Chemin des étoiles 8 B-1348 Louvain-la-Neuve BELGIUM
| | - Yusheng Chen
- Universite de Strasbourg CNRS, ISIS 8 allée Gaspard Monge 67000 Strasbourg FRANCE
| | - Paolo Samorì
- Universite de Strasbourg CNRS, ISIS 8 allée Gaspard Monge 67000 Strasbourg FRANCE
| | - Jean-Christophe Charlier
- UCLouvain Saint-Louis Bruxelles: Universite Saint-Louis - Bruxelles Institute of Condensed Matter and Nanosciences Chemin des étoiles 8 B-1348 Louvain-la-Neuve BELGIUM
| | - Rubén Costa
- Technical University of Munich: Technische Universitat Munchen Chair of Biogenic Functional Materials Schulgasse 22 94315 Straubing GERMANY
| | - Davide Bonifazi
- University of Vienna Faculty of Chemistry: Universitat Wien Fakultat fur Chemie Institute of Organic Chemistry Währinger Strasse 38 1090 Vienna AUSTRIA
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9
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Brun B, Nguyen VH, Moreau N, Somanchi S, Watanabe K, Taniguchi T, Charlier JC, Stampfer C, Hackens B. Graphene Whisperitronics: Transducing Whispering Gallery Modes into Electronic Transport. Nano Lett 2022; 22:128-134. [PMID: 34898223 DOI: 10.1021/acs.nanolett.1c03451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
When confined in circular cavities, graphene relativistic charge carriers occupy whispering gallery modes (WGMs) in analogy to classical acoustic and optical fields. The rich geometrical patterns of the WGMs decorating the local density of states offer promising perspectives to devise new disruptive quantum devices. However, exploiting these highly sensitive resonances requires the transduction of the WGMs to the outside world through source and drain electrodes, a yet unreported configuration. Here, we create a circular p-n island in a graphene device using a polarized scanning gate microscope tip and probe the resulting WGM signatures in in-plane electronic transport through the p-n island. Combining tight-binding simulations and the exact solution of the Dirac equation, we assign the measured device conductance features to WGMs and demonstrate mode selectivity by displacing the p-n island with respect to a constriction. This work therefore constitutes a proof of concept for graphene whisperitronic devices.
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Affiliation(s)
- Boris Brun
- IMCN/NAPS & MODL, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Viet-Hung Nguyen
- IMCN/NAPS & MODL, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Nicolas Moreau
- IMCN/NAPS & MODL, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Sowmya Somanchi
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52062 Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Jean-Christophe Charlier
- IMCN/NAPS & MODL, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Christoph Stampfer
- JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52062 Aachen, Germany
- Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Benoit Hackens
- IMCN/NAPS & MODL, Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
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10
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Zatko V, Dubois SMM, Godel F, Carrétéro C, Sander A, Collin S, Galbiati M, Peiro J, Panciera F, Patriarche G, Brus P, Servet B, Charlier JC, Martin MB, Dlubak B, Seneor P. Band-Gap Landscape Engineering in Large-Scale 2D Semiconductor van der Waals Heterostructures. ACS Nano 2021; 15:7279-7289. [PMID: 33755422 DOI: 10.1021/acsnano.1c00544] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We present a growth process relying on pulsed laser deposition for the elaboration of complex van der Waals heterostructures on large scales, at a 400 °C CMOS-compatible temperature. Illustratively, we define a multilayer quantum well geometry through successive in situ growths, leading to WSe2 being encapsulated into WS2 layers. The structural constitution of the quantum well geometry is confirmed by Raman spectroscopy combined with transmission electron microscopy. The large-scale high homogeneity of the resulting 2D van der Waals heterostructure is also validated by macro- and microscale Raman mappings. We illustrate the benefit of this integrative in situ approach by showing the structural preservation of even the most fragile 2D layers once encapsulated in a van der Waals heterostructure. Finally, we fabricate a vertical tunneling device based on these large-scale layers and discuss the clear signature of electronic transport controlled by the quantum well configuration with ab initio calculations in support. The flexibility of this direct growth approach, with multilayer stacks being built in a single run, allows for the definition of complex 2D heterostructures barely accessible with usual exfoliation or transfer techniques of 2D materials. Reminiscent of the III-V semiconductors' successful exploitation, our approach unlocks virtually infinite combinations of large 2D material families in any complex van der Waals heterostructure design.
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Affiliation(s)
- Victor Zatko
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Simon Mutien-Marie Dubois
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
- Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Florian Godel
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Cécile Carrétéro
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Anke Sander
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Sophie Collin
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Marta Galbiati
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Julian Peiro
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Federico Panciera
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120 Palaiseau, France
| | - Gilles Patriarche
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120 Palaiseau, France
| | - Pierre Brus
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
- Thales Research and Technology, 1 Avenue Augustin Fresnel, 91767 Palaiseau, France
| | - Bernard Servet
- Thales Research and Technology, 1 Avenue Augustin Fresnel, 91767 Palaiseau, France
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Marie-Blandine Martin
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Bruno Dlubak
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
| | - Pierre Seneor
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767 Palaiseau, France
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11
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Piquemal-Banci M, Galceran R, Dubois SMM, Zatko V, Galbiati M, Godel F, Martin MB, Weatherup RS, Petroff F, Fert A, Charlier JC, Robertson J, Hofmann S, Dlubak B, Seneor P. Spin filtering by proximity effects at hybridized interfaces in spin-valves with 2D graphene barriers. Nat Commun 2020; 11:5670. [PMID: 33168805 PMCID: PMC7652852 DOI: 10.1038/s41467-020-19420-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 10/12/2020] [Indexed: 11/09/2022] Open
Abstract
We report on spin transport in state-of-the-art epitaxial monolayer graphene based 2D-magnetic tunnel junctions (2D-MTJs). In our measurements, supported by ab-initio calculations, the strength of interaction between ferromagnetic electrodes and graphene monolayers is shown to fundamentally control the resulting spin signal. In particular, by switching the graphene/ferromagnet interaction, spin transport reveals magneto-resistance signal MR > 80% in junctions with low resistance × area products. Descriptions based only on a simple K-point filtering picture (i.e. MR increase with the number of layers) are not sufficient to predict the behavior of our devices. We emphasize that hybridization effects need to be taken into account to fully grasp the spin properties (such as spin dependent density of states) when 2D materials are used as ultimately thin interfaces. While this is only a first demonstration, we thus introduce the fruitful potential of spin manipulation by proximity effect at the hybridized 2D material / ferromagnet interface for 2D-MTJs.
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Affiliation(s)
- Maëlis Piquemal-Banci
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Regina Galceran
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Simon M-M Dubois
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
- Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain, B-1348, Louvain-la-Neuve, Belgium
| | - Victor Zatko
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Marta Galbiati
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Florian Godel
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Marie-Blandine Martin
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
- Department of Engineering, University of Cambridge, Cambridge, CB21PZ, UK
| | - Robert S Weatherup
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
- University of Manchester at Harwell, Diamond Light Source, Didcot, Oxfordshire, OX11 0DE, UK
| | - Frédéric Petroff
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Albert Fert
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain, B-1348, Louvain-la-Neuve, Belgium
| | - John Robertson
- Department of Engineering, University of Cambridge, Cambridge, CB21PZ, UK
| | - Stephan Hofmann
- Department of Engineering, University of Cambridge, Cambridge, CB21PZ, UK
| | - Bruno Dlubak
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France.
| | - Pierre Seneor
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France.
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12
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Bonnet R, Martin P, Suffit S, Lafarge P, Lherbier A, Charlier JC, Della Rocca ML, Barraud C. Giant spin signals in chemically functionalized multiwall carbon nanotubes. Sci Adv 2020; 6:eaba5494. [PMID: 32789172 PMCID: PMC7399653 DOI: 10.1126/sciadv.aba5494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Transporting quantum information such as the spin information over micrometric or even millimetric distances is a strong requirement for the next-generation electronic circuits such as low-voltage spin-logic devices. This crucial step of transportation remains delicate in nontopologically protected systems because of the volatile nature of spin states. Here, a beneficial combination of different phenomena is used to approach this sought-after milestone for the beyond-Complementary Metal Oxide Semiconductor (CMOS) technology roadmap. First, a strongly spin-polarized charge current is injected using highly spin-polarized hybridized states emerging at the complex ferromagnetic metal/molecule interfaces. Second, the spin information is brought toward the conducting inner shells of a multiwall carbon nanotube used as a confined nanoguide benefiting from both weak spin-orbit and hyperfine interactions. The spin information is finally electrically converted because of a strong magnetoresistive effect. The experimental results are also supported by calculations qualitatively revealing exceptional spin transport properties of this system.
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Affiliation(s)
- Roméo Bonnet
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Pascal Martin
- Université de Paris, ITODYS, CNRS, UMR 7086, 75013 Paris, France
| | - Stéphan Suffit
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Philippe Lafarge
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Aurélien Lherbier
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCLouvain), B-1348 Louvain-la-Neuve, Belgium
| | - Maria Luisa Della Rocca
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
| | - Clément Barraud
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, UMR 7162, 75013 Paris, France
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13
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Banerjee R, Nguyen VH, Granzier-Nakajima T, Pabbi L, Lherbier A, Binion AR, Charlier JC, Terrones M, Hudson EW. Strain Modulated Superlattices in Graphene. Nano Lett 2020; 20:3113-3121. [PMID: 32134680 DOI: 10.1021/acs.nanolett.9b05108] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Numerous theoretically proposed devices and novel phenomena have sought to take advantage of the intense pseudogauge fields that can arise in strained graphene. Many of these proposals, however, require fields to oscillate with a spatial frequency smaller than the magnetic length, while to date only the generation and effects of fields varying at a much larger length scale have been reported. Here, we describe the creation of short wavelength, periodic pseudogauge-fields using rippled graphene under extreme (>10%) strain and study of its effects on Dirac electrons. Combining scanning tunneling microscopy and atomistic calculations, we find that spatially oscillating strain generates a new quantization different from the familiar Landau quantization. Graphene ripples also cause large variations in carbon-carbon bond length, creating an effective electronic superlattice within a single graphene sheet. Our results thus also establish a novel approach of synthesizing effective 2D lateral heterostructures by periodically modulating lattice strain.
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Affiliation(s)
- Riju Banerjee
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Viet-Hung Nguyen
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - Tomotaroh Granzier-Nakajima
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Lavish Pabbi
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Aurelien Lherbier
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - Anna Ruth Binion
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Chemin des étoiles 8, B-1348 Louvain-la-Neuve, Belgium
| | - Mauricio Terrones
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Eric William Hudson
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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14
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Zatko V, Galbiati M, Dubois SMM, Och M, Palczynski P, Mattevi C, Brus P, Bezencenet O, Martin MB, Servet B, Charlier JC, Godel F, Vecchiola A, Bouzehouane K, Collin S, Petroff F, Dlubak B, Seneor P. Band-Structure Spin-Filtering in Vertical Spin Valves Based on Chemical Vapor Deposited WS 2. ACS Nano 2019; 13:14468-14476. [PMID: 31774276 DOI: 10.1021/acsnano.9b08178] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on spin transport in WS2-based 2D-magnetic tunnel junctions (2D-MTJs), unveiling a band structure spin filtering effect specific to the transition metal dichalcogenides (TMDCs) family. WS2 mono-, bi-, and trilayers are derived by a chemical vapor deposition process and further characterized by Raman spectroscopy, atomic force microscopy (AFM), and photoluminescence spectroscopy. The WS2 layers are then integrated in complete Co/Al2O3/WS2/Co MTJ hybrid spin-valve structures. We make use of a tunnel Co/Al2O3 spin analyzer to probe the extracted spin-polarized current from the WS2/Co interface and its evolution as a function of WS2 layer thicknesses. For monolayer WS2, our technological approach enables the extraction of the largest spin signal reported for a TMDC-based spin valve, corresponding to a spin polarization of PCo/WS2 = 12%. Interestingly, for bi- and trilayer WS2, the spin signal is reversed, which indicates a switch in the mechanism of interfacial spin extraction. With the support of ab initio calculations, we propose a model to address the experimentally measured inversion of the spin polarization based on the change in the WS2 band structure while going from monolayer (direct bandgap) to bilayer (indirect bandgap). These experiments illustrate the rich potential of the families of semiconducting 2D materials for the control of spin currents in 2D-MTJs.
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Affiliation(s)
- Victor Zatko
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Marta Galbiati
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Simon Mutien-Marie Dubois
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
- Institute of Condensed Matter and Nanosciences , Université catholique de Louvain , B-1348 Louvain-la-Neuve , Belgium
| | - Mauro Och
- Department of Materials , Imperial College London , Exhibition Road , London SW7 2AZ , U.K
| | - Pawel Palczynski
- Department of Materials , Imperial College London , Exhibition Road , London SW7 2AZ , U.K
| | - Cecilia Mattevi
- Department of Materials , Imperial College London , Exhibition Road , London SW7 2AZ , U.K
| | - Pierre Brus
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
- Thales Research and Technology , 1 avenue Augustin Fresnel , 91767 Palaiseau , France
| | - Odile Bezencenet
- Thales Research and Technology , 1 avenue Augustin Fresnel , 91767 Palaiseau , France
| | - Marie-Blandine Martin
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Bernard Servet
- Thales Research and Technology , 1 avenue Augustin Fresnel , 91767 Palaiseau , France
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences , Université catholique de Louvain , B-1348 Louvain-la-Neuve , Belgium
| | - Florian Godel
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Aymeric Vecchiola
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Karim Bouzehouane
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Sophie Collin
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Frédéric Petroff
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Bruno Dlubak
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Pierre Seneor
- Unité Mixte de Physique, CNRS, Thales , Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
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15
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Abstract
Graphene grown by chemical vapor deposition (CVD) is the most promising material for industrial-scale applications based on graphene monolayers. It also holds promise for spintronics; despite being polycrystalline, spin transport in CVD graphene has been measured over lengths up to 30 μm, which is on par with the best measurements made in single-crystal graphene. These results suggest that grain boundaries (GBs) in CVD graphene, while impeding charge transport, may have little effect on spin transport. However, to date very little is known about the true impact of disordered networks of GBs on spin relaxation. Here, by using first-principles simulations, we derive an effective tight-binding model of graphene GBs in the presence of spin-orbit coupling (SOC), which we then use to evaluate spin transport in realistic morphologies of polycrystalline graphene. The spin diffusion length is found to be independent of the grain size, and it is determined only by the strength of the substrate-induced SOC. This result is consistent with the D'yakonov-Perel' mechanism of spin relaxation in the diffusive regime, but we find that it also holds in the presence of quantum interference. These results clarify the role played by GBs and demonstrate that the average grain size does not dictate the upper limit for spin transport in CVD-grown graphene, a result of fundamental importance for optimizing large-scale graphene-based spintronic devices.
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Affiliation(s)
- Aron W Cummings
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Spain
| | - Simon M-M Dubois
- Institute of Condensed Matter and Nanosciences , Université catholique de Louvain , B-1348 Louvain-la-Neuve , Belgium
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences , Université catholique de Louvain , B-1348 Louvain-la-Neuve , Belgium
| | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats , 08010 Barcelona , Spain
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16
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Piquemal-Banci M, Galceran R, Godel F, Caneva S, Martin MB, Weatherup RS, Kidambi PR, Bouzehouane K, Xavier S, Anane A, Petroff F, Fert A, Dubois SMM, Charlier JC, Robertson J, Hofmann S, Dlubak B, Seneor P. Insulator-to-Metallic Spin-Filtering in 2D-Magnetic Tunnel Junctions Based on Hexagonal Boron Nitride. ACS Nano 2018; 12:4712-4718. [PMID: 29697954 DOI: 10.1021/acsnano.8b01354] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report on the integration of atomically thin 2D insulating hexagonal boron nitride (h-BN) tunnel barriers into magnetic tunnel junctions (2D-MTJs) by fabricating two illustrative systems (Co/h-BN/Co and Co/h-BN/Fe) and by discussing h-BN potential for metallic spin filtering. The h-BN is directly grown by chemical vapor deposition on prepatterned Co and Fe stripes. Spin-transport measurements reveal tunnel magneto-resistances in these h-BN-based MTJs as high as 12% for Co/h-BN/h-BN/Co and 50% for Co/h-BN/Fe. We analyze the spin polarizations of h-BN/Co and h-BN/Fe interfaces extracted from experimental spin signals in light of spin filtering at hybrid chemisorbed/physisorbed h-BN, with support of ab initio calculations. These experiments illustrate the strong potential of h-BN for MTJs and are expected to ignite further investigations of 2D materials for large signal spin devices.
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Affiliation(s)
- Maëlis Piquemal-Banci
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Regina Galceran
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Florian Godel
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Sabina Caneva
- Department of Engineering , University of Cambridge , Cambridge CB21PZ , United Kingdom
| | - Marie-Blandine Martin
- Department of Engineering , University of Cambridge , Cambridge CB21PZ , United Kingdom
| | - Robert S Weatherup
- Department of Engineering , University of Cambridge , Cambridge CB21PZ , United Kingdom
| | - Piran R Kidambi
- Department of Engineering , University of Cambridge , Cambridge CB21PZ , United Kingdom
| | - Karim Bouzehouane
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Stephane Xavier
- Thales Research and Technology , 1 avenue Augustin Fresnel , 91767 Palaiseau , France
| | - Abdelmadjid Anane
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Frédéric Petroff
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Albert Fert
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Simon Mutien-Marie Dubois
- Institute of Condensed Matter and Nanosciences (IMCN) , Université Catholique de Louvain , B-1348 Louvain-la-Neuve , Belgium
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences (IMCN) , Université Catholique de Louvain , B-1348 Louvain-la-Neuve , Belgium
| | - John Robertson
- Department of Engineering , University of Cambridge , Cambridge CB21PZ , United Kingdom
| | - Stephan Hofmann
- Department of Engineering , University of Cambridge , Cambridge CB21PZ , United Kingdom
| | - Bruno Dlubak
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | - Pierre Seneor
- Unité Mixte de Physique, CNRS, Thales, Univ Paris-Sud, Université Paris-Saclay , 91767 Palaiseau , France
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17
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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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18
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Mortazavi B, Lherbier A, Fan Z, Harju A, Rabczuk T, Charlier JC. Thermal and electronic transport characteristics of highly stretchable graphene kirigami. Nanoscale 2017; 9:16329-16341. [PMID: 29051943 DOI: 10.1039/c7nr05231f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
For centuries, cutting and folding papers with special patterns have been used to build beautiful, flexible and complex three-dimensional structures. Inspired by the old idea of kirigami (paper cutting), and the outstanding properties of graphene, recently graphene kirigami structures were fabricated to enhance the stretchability of graphene. However, the possibility of further tuning the electronic and thermal transport along the 2D kirigami structures has remained original to investigate. We therefore performed extensive atomistic simulations to explore the electronic, heat and load transfer along various graphene kirigami structures. The mechanical response and thermal transport were explored using classical molecular dynamics simulations. We then used a real-space Kubo-Greenwood formalism to investigate the charge transport characteristics in graphene kirigami. Our results reveal that graphene kirigami structures present highly anisotropic thermal and electrical transport. Interestingly, we show the possibility of tuning the thermal conductivity of graphene by four orders of magnitude. Moreover, we discuss the engineering of kirigami patterns to further enhance their stretchability by more than 10 times as compared with pristine graphene. Our study not only provides a general understanding concerning the engineering of electronic, thermal and mechanical response of graphene, but more importantly can also be useful to guide future studies with respect to the synthesis of other 2D material kirigami structures, to reach highly flexible and stretchable nanostructures with finely tunable electronic and thermal properties.
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Affiliation(s)
- Bohayra Mortazavi
- Institute of Structural Mechanics, Bauhaus-Universität Weimar, Marienstr. 15, D-99423 Weimar, Germany.
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19
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Adjizian JJ, Vlandas A, Rio J, Charlier JC, Ewels CP. Ab initio infrared vibrational modes for neutral and charged small fullerenes (C20, C24, C26, C28, C30 and C60). Philos Trans A Math Phys Eng Sci 2016; 374:rsta.2015.0323. [PMID: 27501975 PMCID: PMC4978747 DOI: 10.1098/rsta.2015.0323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/05/2016] [Indexed: 06/06/2023]
Abstract
We calculate the infrared (IR) absorption spectra using DFT B3LYP(6-311G) for a range of small closed-cage fullerenes, Cn, n=20, 24, 26, 28, 30 and 60, in both neutral and multiple positive and negative charge states. The results are of use, notably, for direct comparison with observed IR absorption in the interstellar medium. Frequencies fall typically into two ranges, with C-C stretch modes around 1100-1500 cm(-1) (6.7-9.1 μm) and fullerene-specific radial motion associated with under-coordinated carbon at pentagonal sites in the range 600-800 cm(-1) (12.5-16.7 μm). Notably, negatively charged fullerenes show significantly stronger absorption intensities than neutral species. The results suggest that small cage fullerenes, and notably metallic endofullerenes, may be responsible for many of the unassigned interstellar IR spectral lines.This article is part of the themed issue 'Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene'.
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Affiliation(s)
- Jean-Joseph Adjizian
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Chemin des Étoiles 8, 1348 Louvain-la-Neuve, Belgium
| | - Alexis Vlandas
- BioMEMS, Université Lille, CNRS, ISEN, UMR 8520-IEMN, 59000 Lille, France
| | - Jeremy Rio
- Institut des Materiaux Jean Rouxel, CNRS, University of Nantes, UMR6502, 2 Rue de la Houssiniere, BP32229, 44322 Nantes Cedex 3, France
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Chemin des Étoiles 8, 1348 Louvain-la-Neuve, Belgium
| | - Chris P Ewels
- Institut des Materiaux Jean Rouxel, CNRS, University of Nantes, UMR6502, 2 Rue de la Houssiniere, BP32229, 44322 Nantes Cedex 3, France
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20
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Adjizian JJ, Lherbier A, M-M Dubois S, Botello-Méndez AR, Charlier JC. The electronic and transport properties of two-dimensional conjugated polymer networks including disorder. Nanoscale 2016; 8:1642-1651. [PMID: 26692370 DOI: 10.1039/c5nr06825h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Two-dimensional (2D) conjugated polymers exhibit electronic structures analogous to that of graphene with the peculiarity of π-π* bands which are fully symmetric and isolated. In the present letter, the suitability of these materials for electronic applications is analyzed and discussed. In particular, realistic 2D conjugated polymer networks with a structural disorder such as monomer vacancies are investigated. Indeed, during bottom-up synthesis, these irregularities are unavoidable and their impact on the electronic properties is investigated using both ab initio and tight-binding techniques. The tight-binding model is combined with a real space Kubo-Greenwood approach for the prediction of transport characteristics for monomer vacancy concentrations ranging from 0.5% to 2%. As expected, long mean free paths and high mobilities are predicted for low defect densities. At low temperatures and for high defect densities, strong localization phenomena originating from quantum interferences of multiple scattering paths are observed in the close vicinity of the Dirac energy region while the absence of localization effects is predicted away from this region suggesting a sharp mobility transition. These predictions show that 2D conjugated polymer networks are good candidates to pave the way for the ultimate scaling and performances of future molecular nanoelectronic devices.
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Affiliation(s)
- Jean-Joseph Adjizian
- Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Chemin des étoiles 8, 1348 Louvain-la-neuve, Belgium.
| | - Aurélien Lherbier
- Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Chemin des étoiles 8, 1348 Louvain-la-neuve, Belgium.
| | - Simon M-M Dubois
- Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Chemin des étoiles 8, 1348 Louvain-la-neuve, Belgium.
| | - Andrés Rafael Botello-Méndez
- Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Chemin des étoiles 8, 1348 Louvain-la-neuve, Belgium.
| | - Jean-Christophe Charlier
- Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Chemin des étoiles 8, 1348 Louvain-la-neuve, Belgium.
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21
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Romero Aburto R, Alemany LB, Weldeghiorghis TK, Ozden S, Peng Z, Lherbier A, Botello Méndez AR, Tiwary CS, Taha-Tijerina J, Yan Z, Tabata M, Charlier JC, Tour JM, Ajayan PM. Chemical Makeup and Hydrophilic Behavior of Graphene Oxide Nanoribbons after Low-Temperature Fluorination. ACS Nano 2015; 9:7009-7018. [PMID: 26020447 DOI: 10.1021/acsnano.5b01330] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Here we investigated the fluorination of graphene oxide nanoribbons (GONRs) using H2 and F2 gases at low temperature, below 200 °C, with the purpose of elucidating their structure and predicting a fluorination mechanism. The importance of this study is the understanding of how fluorine functional groups are incorporated in complex structures, such as GONRs, as a function of temperature. The insight provided herein can potentially help engineer application-oriented materials for several research and industrial sectors. Direct (13)C pulse magic angle spinning (MAS) nuclear magnetic resonance (NMR) confirmed the presence of epoxy, hydroxyl, ester and ketone carbonyl, tertiary alkyl fluorides, as well as graphitic sp(2)-hybridized carbon. Moreover, (19)F-(13)C cross-polarization MAS NMR with (1)H and (19)F decoupling confirmed the presence of secondary alkyl fluoride (CF2) groups in the fluorinated graphene oxide nanoribbon (FGONR) structures fluorinated above 50 °C. First-principles density functional theory calculations gained insight into the atomic arrangement of the most dominant chemical groups. The fluorinated GONRs present atomic fluorine percentages in the range of 6-35. Interestingly, the FGONRs synthesized up to 100 °C, with 6-19% of atomic fluorine, exhibit colloidal similar stability in aqueous environments when compared to GONRs. This colloidal stability is important because it is not common for materials with up to 19% fluorine to have a high degree of hydrophilicity.
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Affiliation(s)
| | | | - Thomas K Weldeghiorghis
- ∥Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | | | | | - Aurélien Lherbier
- ⊥Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, 1348 Belgium
| | - Andrés Rafael Botello Méndez
- ⊥Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, 1348 Belgium
| | | | | | | | | | - Jean-Christophe Charlier
- ⊥Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain, Louvain-la-Neuve, 1348 Belgium
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22
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Botello-Méndez AR, Dubois SMM, Lherbier A, Charlier JC. Achievements of DFT for the investigation of graphene-related nanostructures. Acc Chem Res 2014; 47:3292-300. [PMID: 25350633 DOI: 10.1021/ar500281v] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CONSPECTUS: Graphene-related nanostructures stand out as exceptional materials due to both their wide range of properties and their expanse of interest in both applied and fundamental research. They are good examples of nanoscale materials for which the properties do not necessarily replicate those of the bulk. For the description and the understanding of their properties, it is clear that a general quantum-mechanical approach is mandatory. The remarkable result of density functional theory (DFT) is that the quantum-mechanical description of materials at the ground state is made amenable to simulations at a relatively low computational cost. The knowledge of materials has undergone a revolution after the introduction of DFT as an unrivaled instrument for the investigation of materials properties through computer experiments. Their deeper understanding comes from a variety of tools developed from concepts intrinsically present in DFT, notably the total energy and the charge density. Such tools allow the prediction of a diverse set of physicochemical properties relevant for material scientists. This Account lays out an example-driven tour through the achievements of ground-state DFT applied to the description of graphene-related nanostructures and to the deep understanding of their outstanding properties. After a brief introduction to DFT, the survey starts with the determination of the most basic properties that can be obtained from DFT, that is, band structures, lattice parameters, and spin ground state. Next follows an exploration of how total energies of different systems can give information about relative stability, formation energies, and reaction paths. Exploiting the derivatives of the energy with respect to displacements leads the way toward the extraction of vibrational and mechanical properties. In addition, a close examination of the charge density gives information about charge transfer mechanisms, which can be linked to chemical reactivity. The ground state density and Hamiltonian finally connect to the concepts behind transport phenomena, which drive much of the application-oriented research on graphene and graphene-related nanostructures. In each section, a selection of cases that are of current importance are used to illustrate the use and relevance of DFT-based techniques. In summary, this Account presents an introductory landscape of the possibilities of ground-state DFT for the study of graphene-related nanostructures. The prospect is rich, and the use of DFT for the study of graphene-related nanostructures will continue to be fruitful for the advancement of these and other materials.
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Affiliation(s)
- Andrés R. Botello-Méndez
- Institute of Condensed
Matter
and Nanosciences, Université catholique de Louvain, Chemin des
étoiles 8, 1348 Louvain-la-neuve, Belgium
| | - Simon M.-M. Dubois
- Institute of Condensed
Matter
and Nanosciences, Université catholique de Louvain, Chemin des
étoiles 8, 1348 Louvain-la-neuve, Belgium
| | - Aurélien Lherbier
- Institute of Condensed
Matter
and Nanosciences, Université catholique de Louvain, Chemin des
étoiles 8, 1348 Louvain-la-neuve, Belgium
| | - Jean-Christophe Charlier
- Institute of Condensed
Matter
and Nanosciences, Université catholique de Louvain, Chemin des
étoiles 8, 1348 Louvain-la-neuve, Belgium
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23
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Randel JC, Niestemski FC, Botello-Mendez AR, Mar W, Ndabashimiye G, Melinte S, Dahl JEP, Carlson RMK, Butova ED, Fokin AA, Schreiner PR, Charlier JC, Manoharan HC. Unconventional molecule-resolved current rectification in diamondoid-fullerene hybrids. Nat Commun 2014; 5:4877. [PMID: 25202942 PMCID: PMC4164769 DOI: 10.1038/ncomms5877] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 07/31/2014] [Indexed: 02/05/2023] Open
Abstract
The unimolecular rectifier is a fundamental building block of molecular electronics. Rectification in single molecules can arise from electron transfer between molecular orbitals displaying asymmetric spatial charge distributions, akin to p-n junction diodes in semiconductors. Here we report a novel all-hydrocarbon molecular rectifier consisting of a diamantane-C60 conjugate. By linking both sp(3) (diamondoid) and sp(2) (fullerene) carbon allotropes, this hybrid molecule opposingly pairs negative and positive electron affinities. The single-molecule conductances of self-assembled domains on Au(111), probed by low-temperature scanning tunnelling microscopy and spectroscopy, reveal a large rectifying response of the molecular constructs. This specific electronic behaviour is postulated to originate from the electrostatic repulsion of diamantane-C60 molecules due to positively charged terminal hydrogen atoms on the diamondoid interacting with the top electrode (scanning tip) at various bias voltages. Density functional theory computations scrutinize the electronic and vibrational spectroscopic fingerprints of this unique molecular structure and corroborate the unconventional rectification mechanism.
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Affiliation(s)
- Jason C Randel
- 1] SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA [2] Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Francis C Niestemski
- 1] SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA [2] Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Andrés R Botello-Mendez
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, B-1348 Louvain-La-Neuve, Belgium
| | - Warren Mar
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
| | - Georges Ndabashimiye
- 1] SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA [2] Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Sorin Melinte
- Institute of Information and Communication Technologies, Electronics and Applied Mathematics, Université catholique de Louvain, B-1348 Louvain-La-Neuve, Belgium
| | - Jeremy E P Dahl
- SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA
| | - Robert M K Carlson
- SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA
| | - Ekaterina D Butova
- Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen, Germany
| | - Andrey A Fokin
- 1] Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen, Germany [2] Department of Organic Chemistry, Kiev Polytechnic Institute, UA-03056 Kiev, Ukraine
| | - Peter R Schreiner
- Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen, Germany
| | - Jean-Christophe Charlier
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, B-1348 Louvain-La-Neuve, Belgium
| | - Hari C Manoharan
- 1] SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025, USA [2] Department of Physics, Stanford University, Stanford, California 94305, USA
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24
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Qi Z, Rodríguez-Manzo JA, Botello-Méndez A, Hong SJ, Stach EA, Park YW, Charlier JC, Drndić M, Johnson ATC. Correlating atomic structure and transport in suspended graphene nanoribbons. Nano Lett 2014; 14:4238-44. [PMID: 24954396 PMCID: PMC4134140 DOI: 10.1021/nl501872x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Indexed: 05/22/2023]
Abstract
Graphene nanoribbons (GNRs) are promising candidates for next generation integrated circuit (IC) components; this fact motivates exploration of the relationship between crystallographic structure and transport of graphene patterned at IC-relevant length scales (<10 nm). We report on the controlled fabrication of pristine, freestanding GNRs with widths as small as 0.7 nm, paired with simultaneous lattice-resolution imaging and electrical transport characterization, all conducted within an aberration-corrected transmission electron microscope. Few-layer GNRs very frequently formed bonded-bilayers and were remarkably robust, sustaining currents in excess of 1.5 μA per carbon bond across a 5 atom-wide ribbon. We found that the intrinsic conductance of a sub-10 nm bonded bilayer GNR scaled with width as GBL(w) ≈ 3/4(e(2)/h)w, where w is the width in nanometers, while a monolayer GNR was roughly five times less conductive. Nanosculpted, crystalline monolayer GNRs exhibited armchair-terminated edges after current annealing, presenting a pathway for the controlled fabrication of semiconducting GNRs with known edge geometry. Finally, we report on simulations of quantum transport in GNRs that are in qualitative agreement with the observations.
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Affiliation(s)
- Zhengqing
John Qi
- Department
of Physics and Astronomy, University of
Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Julio A. Rodríguez-Manzo
- Department
of Physics and Astronomy, University of
Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Andrés
R. Botello-Méndez
- Institute
of Condensed Matter and Nanosciences, Université
Catholique de Louvain, Chemin des étoiles 8, 1348 Louvain-la-Neuve, Belgium
| | - Sung Ju Hong
- Department
of Physics and Astronomy, University of
Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department
of Physics and Astronomy, Seoul National
University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-747, Korea
| | - Eric A. Stach
- Center
for Functional Nanomaterials, Brookhaven
National Laboratory, Upton, New York 11973, United States
| | - Yung Woo Park
- Department
of Physics and Astronomy, Seoul National
University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-747, Korea
- E-mail: (Y.W.P.)
| | - Jean-Christophe Charlier
- Institute
of Condensed Matter and Nanosciences, Université
Catholique de Louvain, Chemin des étoiles 8, 1348 Louvain-la-Neuve, Belgium
| | - Marija Drndić
- Department
of Physics and Astronomy, University of
Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- E-mail: (M.D.)
| | - A. T. Charlie Johnson
- Department
of Physics and Astronomy, University of
Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- E-mail: (A.T.C.J.)
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25
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Cretu O, Botello-Mendez AR, Janowska I, Pham-Huu C, Charlier JC, Banhart F. Electrical transport measured in atomic carbon chains. Nano Lett 2013; 13:3487-3493. [PMID: 23879314 DOI: 10.1021/nl4018918] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The first electrical-transport measurements of monatomic carbon chains are reported in this study. The chains were obtained by unraveling carbon atoms from graphene ribbons while an electrical current flowed through the ribbon and, successively, through the chain. The formation of the chains was accompanied by a characteristic drop in the electrical conductivity. The conductivity of the chains was much lower than previously predicted for ideal chains. First-principles calculations using both density functional and many-body perturbation theory show that strain in the chains has an increasing effect on the conductivity as the length of the chains increases. Indeed, carbon chains are always under varying nonzero strain that transforms their atomic structure from the cumulene to the polyyne configuration, thus inducing a tunable band gap. The modified electronic structure and the characteristics of the contact to the graphitic periphery explain the low conductivity of the locally constrained carbon chain.
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Affiliation(s)
- Ovidiu Cretu
- Institut de Physique et Chimie des Matériaux, Université de Strasbourg, UMR 7504 CNRS, Strasbourg, France
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26
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Lherbier A, Botello-Méndez AR, Charlier JC. Electronic and transport properties of unbalanced sublattice N-doping in graphene. Nano Lett 2013; 13:1446-1450. [PMID: 23477418 DOI: 10.1021/nl304351z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Using both first-principles techniques and a real-space Kubo-Greenwood approach, electronic and transport properties of nitrogen-doped graphene with a single sublattice preference are investigated. Such a breaking of the sublattice symmetry leads to the appearance of a true band gap in graphene electronic spectrum even for a random distribution of the N dopants. More surprisingly, a natural spatial separation of both types of charge carriers at the band edge is predicted, leading to a highly asymmetric electronic transport. Both the presence of a band gap, allowing large on/off ratio, and an asymmetric transport pave a new route toward efficient graphene-based field-effect transistors.
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Affiliation(s)
- Aurélien Lherbier
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCL), 1348 Louvain-la-Neuve, Belgium.
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27
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Botello-Méndez AR, Cruz-Silva E, Romo-Herrera JM, López-Urías F, Terrones M, Sumpter BG, Terrones H, Charlier JC, Meunier V. Quantum transport in graphene nanonetworks. Nano Lett 2011; 11:3058-3064. [PMID: 21696176 DOI: 10.1021/nl2002268] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The quantum transport properties of graphene nanoribbon networks are investigated using first-principles calculations based on density functional theory. Focusing on systems that can be experimentally realized with existing techniques, both in-plane conductance in interconnected graphene nanoribbons and tunneling conductance in out-of-plane nanoribbon intersections were studied. The characteristics of the ab initio electronic transport through in-plane nanoribbon cross-points is found to be in agreement with results obtained with semiempirical approaches. Both simulations confirm the possibility of designing graphene nanoribbon-based networks capable of guiding electrons along desired and predetermined paths. In addition, some of these intersections exhibit different transmission probability for spin up and spin down electrons, suggesting the possible applications of such networks as spin filters. Furthermore, the electron transport properties of out-of-plane nanoribbon cross-points of realistic sizes are described using a combination of first-principles and tight-binding approaches. The stacking angle between individual sheets is found to play a central role in dictating the electronic transmission probability within the networks.
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Affiliation(s)
- Andrés R Botello-Méndez
- Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain (UCL), Chemin des Etoiles 8, bte L7.03.01, 1348 Louvain-la-Neuve, Belgium.
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28
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Soriano D, Leconte N, Ordejón P, Charlier JC, Palacios JJ, Roche S. Magnetoresistance and magnetic ordering fingerprints in hydrogenated graphene. Phys Rev Lett 2011; 107:016602. [PMID: 21797560 DOI: 10.1103/physrevlett.107.016602] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Indexed: 05/31/2023]
Abstract
Spin-dependent features in the conductivity of graphene, chemically modified by a random distribution of hydrogen adatoms, are explored theoretically. The spin effects are taken into account using a mean-field self-consistent Hubbard model derived from first-principles calculations. A Kubo transport methodology is used to compute the spin-dependent transport fingerprints of weakly hydrogenated graphene-based systems with realistic sizes. Conductivity responses are obtained for paramagnetic, antiferromagnetic, or ferromagnetic macroscopic states, constructed from the mean-field solutions obtained for small graphene supercells. Magnetoresistance signals up to ∼7% are calculated for hydrogen densities around 0.25%. These theoretical results could serve as guidance for experimental observation of induced magnetism in graphene.
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Affiliation(s)
- David Soriano
- Departamento de Física Aplicada, Universidad de Alicante, San Vicente del Raspeig, Spain
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29
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Perea-López N, Rebollo-Plata B, Briones-León JA, Morelos-Gómez A, Hernández-Cruz D, Hirata GA, Meunier V, Botello-Méndez AR, Charlier JC, Maruyama B, Muñoz-Sandoval E, López-Urías F, Terrones M, Terrones H. Millimeter-long carbon nanotubes: outstanding electron-emitting sources. ACS Nano 2011; 5:5072-5077. [PMID: 21609029 DOI: 10.1021/nn201149y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We are reporting the fabrication of a very efficient electron source using millimeter-long and highly crystalline carbon nanotubes. These devices start to emit electrons at fields as low as 0.17 V/μm and reach threshold emission at 0.24 V/μm. In addition, these electron sources are very stable and can achieve a peak current density of 750 mA cm(-2) at only 0.45 V/μm. In order to demonstrate intense electron beam generation, these devices were used to produce visible light by cathodoluminescence. Finally, density functional theory calculations were used to rationalize the measured electronic field emission properties in open carbon nanotubes of different lengths. The modeling establishes a clear correlation between length and field enhancement factor.
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Affiliation(s)
- Néstor Perea-López
- Department of Physics, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802-6300, United States
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30
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Abstract
The sensing properties of carbon nanotubes (CNTs) decorated with gold nanoparticles have been investigated by means of combined theoretical and experimental approaches. On one hand, first-principles and nonequilibrium Green's functions techniques give access to the microscopic features of the sensing mechanisms in individual nanotubes, such as electronic charge transfers and quantum conductances. On the other hand, drop coating deposition of carbon nanotubes decorated with gold nanoparticles onto sensor substrates and their characterization in the detection of pollutants such as NO(2), CO, and C(6)H(6) provide insight into the sensing ability of nanotube mats. Using the present combined approaches, the improvement in the detection of some specific gases (NO(2) and CO) using Au-functionalized nanotubes is explained. However, for other gases such as C(6)H(6), the Au nanoparticles do not seem to play a crucial role in the sensing process when compared with pristine CNTs functionalized with oxygen plasma. Indeed, these different situations can be explained by identifying the relationship between the change of resistance (macroscopic feature) and the shift of the Fermi level (microscopic feature) after gas adsorption. The understanding of the sensing ability at the atomic level opens the way to design new gas sensors and to tune their selectivity by predicting the nature of the metal that is the most appropriate to detect specific molecular species.
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Affiliation(s)
- Zeila Zanolli
- Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain, Place Croix du Sud 1 (NAPS-ETSF-Boltzmann), 1348 Louvain-la-Neuve, Belgium.
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31
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Leconte N, Soriano D, Roche S, Ordejon P, Charlier JC, Palacios JJ. Magnetism-dependent transport phenomena in hydrogenated graphene: from spin-splitting to localization effects. ACS Nano 2011; 5:3987-92. [PMID: 21469688 DOI: 10.1021/nn200558d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Spin-dependent transport in hydrogenated two-dimensional graphene is explored theoretically. Adsorbed atomic hydrogen impurities can either induce a local antiferromagnetic, ferromagnetic, or nonmagnetic state depending on their density and relative distribution. To describe the various magnetic possibilities of hydrogenated graphene, a self-consistent Hubbard Hamiltonian, optimized by ab initio calculations, is first solved in the mean field approximation for small graphene cells. Then, an efficient order N Kubo transport methodology is implemented, enabling large scale simulations of functionalized graphene. Depending on the underlying intrinsic magnetic ordering of hydrogen-induced spins, remarkably different transport features are predicted for the same impurity concentration. Indeed, while the disordered nonmagnetic graphene system exhibits a transition from diffusive to localization regimes, the intrinsic ferromagnetic state exhibits unprecedented robustness toward quantum interference, maintaining, for certain resonant energies, a quasiballistic regime up to the micrometer scale. Consequently, low temperature transport measurements could unveil the presence of a magnetic state in weakly hydrogenated graphene.
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Affiliation(s)
- Nicolas Leconte
- Université Catholique de Louvain, Institute of Condensed Matter and Nanosciences (IMCN), Place Croix du Sud 1 (NAPS-Boltzmann), 1348 Louvain-la-Neuve, Belgium.
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32
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Cruz-Silva E, Lopez-Urias F, Munoz-Sandoval E, Sumpter BG, Terrones H, Charlier JC, Meunier V, Terrones M. Phosphorus and phosphorus-nitrogen doped carbon nanotubes for ultrasensitive and selective molecular detection. Nanoscale 2011; 3:1008-1013. [PMID: 21152534 DOI: 10.1039/c0nr00519c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A first-principles approach is used to establish that substitutional phosphorus atoms within carbon nanotubes strongly modify the chemical properties of the surface, thus creating highly localized sites with specific affinity towards acceptor molecules. Phosphorus-nitrogen co-dopants within the tubes have a similar effect for acceptor molecules, but the P-N bond can also accept charge, resulting in affinity towards donor molecules. This molecular selectivity is illustrated in CO and NH3 adsorbed on PN-doped nanotubes, O2 on P-doped nanotubes, and NO2 and SO2 on both P- and PN-doped nanotubes. The adsorption of different chemical species onto the doped nanotubes modifies the dopant-induced localized states, which subsequently alter the electronic conductance. Although SO2 and CO adsorptions cause minor shifts in electronic conductance, NH3, NO2, and O2 adsorptions induce the suppression of a conductance dip. Conversely, the adsorption of NO2 on PN-doped nanotubes is accompanied with the appearance of an additional dip in conductance, correlated with a shift of the existing ones. Overall these changes in electric conductance provide an efficient way to detect selectively the presence of specific molecules. Additionally, the high oxidation potential of the P-doped nanotubes makes them good candidates for electrode materials in hydrogen fuel cells.
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Affiliation(s)
- Eduardo Cruz-Silva
- Oak Ridge National Laboratory, P.O. Box 2008, MS6367, Oak Ridge, Tennessee 37831-6367, USA.
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33
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Lherbier A, Dubois SMM, Declerck X, Roche S, Niquet YM, Charlier JC. Two-dimensional graphene with structural defects: elastic mean free path, minimum conductivity, and Anderson transition. Phys Rev Lett 2011; 106:046803. [PMID: 21405346 DOI: 10.1103/physrevlett.106.046803] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Indexed: 05/30/2023]
Abstract
Quantum transport properties of disordered graphene with structural defects (Stone-Wales and divacancies) are investigated using a realistic π-π* tight-binding model elaborated from ab initio calculations. Mean free paths and semiclassical conductivities are then computed as a function of the nature and density of defects (using an order-N real-space Kubo-Greenwood method). By increasing the defect density, the decay of the semiclassical conductivities is predicted to saturate to a minimum value of 4e2/πh over a large range (plateau) of carrier density (>0.5×10(14) cm(-20). Additionally, strong contributions of quantum interferences suggest that the Anderson localization regime could be experimentally measurable for a defect density as low as 1%.
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Affiliation(s)
- Aurélien Lherbier
- Institute of Condensed Matter and Nanoscience (IMCN), Université Catholique de Louvain (UCL), Louvain-la-Neuve, Belgium
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34
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Biel B, Cresti A, Avriller R, Dubois S, López-Bezanilla A, Triozon F, Blase X, Charlier JC, Roche S. Mobility gaps in disordered graphene-based materials: an ab initio -based tight-binding approach to mesoscopic transport. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/pssc.200983826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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35
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Leconte N, Moser J, Ordejón P, Tao H, Lherbier A, Bachtold A, Alsina F, Sotomayor Torres CM, Charlier JC, Roche S. Damaging graphene with ozone treatment: a chemically tunable metal-insulator transition. ACS Nano 2010; 4:4033-8. [PMID: 20695517 DOI: 10.1021/nn100537z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present a multiscale ab initio study of electronic and transport properties of two-dimensional graphene after epoxide functionalization via ozone treatment. The orbital rehybridization induced by the epoxide groups triggers a strong intervalley scattering and changes dramatically the conduction properties of graphene. By varying the coverage density of epoxide defects from 0.1 to 4%, charge conduction can be tuned from a diffusive to a strongly localized regime, with localization lengths down to a few nanometers long. Experimental results supporting the interpretation as a metal-insulator transition are also provided.
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Affiliation(s)
- Nicolas Leconte
- IMCN, Universite Catholique de Louvain, Place Croix du Sud 1 (PCPM-ETSF), B-1348 Louvain-la-Neuve, Belgium
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36
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Dubois SMM, Lopez-Bezanilla A, Cresti A, Triozon F, Biel B, Charlier JC, Roche S. Quantum transport in graphene nanoribbons: effects of edge reconstruction and chemical reactivity. ACS Nano 2010; 4:1971-6. [PMID: 20355732 DOI: 10.1021/nn100028q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We present first-principles transport calculations of graphene nanoribbons with chemically reconstructed edge profiles. Depending on the geometry of the defect and the degree of hydrogenation, spectacularly different transport mechanisms are obtained. In the case of monohydrogenated pentagon (heptagon) defects, an effective acceptor (donor) character results in strong electron-hole conductance asymmetry. In contrast, weak backscattering is obtained for defects that preserve the benzenoid structure of graphene. Based on a tight-binding model derived from ab initio calculations, evidence for large conductance scaling fluctuations are found in disordered ribbons with lengths up to the micrometer scale.
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Affiliation(s)
- Simon M-M Dubois
- Institute of Condensed Matter and Nanosciences (IMCN), European Theoretical Spectroscopy Facility (ETSF), Universite Catholique de Louvain, Place Croix du Sud 1 (PCPM-Boltzmann), 1348 Louvain-la-Neuve, Belgium.
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37
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Cruz-Silva E, López-Urías F, Muñoz-Sandoval E, Sumpter BG, Terrones H, Charlier JC, Meunier V, Terrones M. Electronic transport and mechanical properties of phosphorus- and phosphorus-nitrogen-doped carbon nanotubes. ACS Nano 2009; 3:1913-21. [PMID: 19572616 DOI: 10.1021/nn900286h] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We present a density functional theory study of the electronic structure, quantum transport and mechanical properties of recently synthesized phosphorus (P) and phosphorus-nitrogen (PN) doped single-walled carbon nanotubes. The results demonstrate that substitutional P and PN doping creates localized electronic states that modify the electron transport properties by acting as scattering centers. Nonetheless, for low doping concentrations (1 doping site per ∼200 atoms), the quantum conductance for metallic nanotubes is found to be only slightly reduced. The substitutional doping also alters the mechanical strength, leading to a 50% reduction in the elongation upon fracture, while Young's modulus remains approximately unchanged. Overall, the PN- and P-doped nanotubes display promising properties for components in composite materials and, in particular, for fast response and ultra sensitive sensors operating at the molecular level.
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Affiliation(s)
- Eduardo Cruz-Silva
- Laboratory for Nanoscience and Nanotechnology Research (LINAN) and Advanced Materials Department, IPICyT. Camino a la Presa Sn. Jose 2055, San Luis Potosí, Mexico, 78216
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38
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Moors M, Amara H, de Bocarmé TV, Bichara C, Ducastelle F, Kruse N, Charlier JC. Early stages in the nucleation process of carbon nanotubes. ACS Nano 2009; 3:511-516. [PMID: 19220007 DOI: 10.1021/nn800769w] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The early stages of carbon nanotube nucleation are investigated using field ion/electron microscopy along with in situ local chemical probing of a single nanosized nickel crystal. To go beyond experiments, tight-binding Monte Carlo simulations are performed on oriented Ni slabs. Real-time field electron imaging demonstrates a carbon-induced increase of the number density of steps in the truncated vertices of a polyhedral Ni nanoparticle. The necessary diffusion and step-site trapping of adsorbed carbon atoms are observed in the simulations and precede the nucleation of graphene-based sheets in these steps. Chemical probing of selected nanofacets of the Ni crystal reveals the occurrence of Cn (n=1-4) surface species. Kinetic studies prove C2+ species are formed from C1 with a delay time of several milliseconds at 623 K. Carbon dimers, C2, must not necessarily be formed on the Ni surface. Tight-binding Monte Carlo simulations reveal the high stability of such dimers in the first layer beneath the surface.
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Affiliation(s)
- Matthieu Moors
- Chemical Physics of Materials, Faculté des Sciences, Université Libre de Bruxelles, Bruxelles, Belgium
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39
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Cruz-Silva E, Cullen DA, Gu L, Romo-Herrera JM, Muñoz-Sandoval E, López-Urías F, Sumpter BG, Meunier V, Charlier JC, Smith DJ, Terrones H, Terrones M. Heterodoped nanotubes: theory, synthesis, and characterization of phosphorus-nitrogen doped multiwalled carbon nanotubes. ACS Nano 2008; 2:441-8. [PMID: 19206568 DOI: 10.1021/nn700330w] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Arrays of multiwalled carbon nanotubes doped with phosphorus (P) and nitrogen (N) are synthesized using a solution of ferrocene, triphenyl-phosphine, and benzylamine in conjunction with spray pyrolysis. We demonstrate that iron phosphide (Fe(3)P) nanoparticles act as catalysts during nanotube growth, leading to the formation of novel PN-doped multiwalled carbon nanotubes. The samples were examined by high resolution electron microscopy and microanalysis techniques, and their chemical stability was explored by means of thermogravimetric analysis in the presence of oxygen. The PN-doped structures reveal important morphology and chemical changes when compared to N-doped nanotubes. These types of heterodoped nanotubes are predicted to offer many new opportunities in the fabrication of fast-response chemical sensors.
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Affiliation(s)
- Eduardo Cruz-Silva
- Advanced Materials Department, IPICyT, Camino a Presa San José, 2055, San Luis Potosí 78216, México
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40
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Ewels CP, Van Lier G, Geerlings P, Charlier JC. Meta-Code for Systematic Analysis of Chemical Addition (SACHA): Application to Fluorination of C70 and Carbon Nanostructure Growth. J Chem Inf Model 2007; 47:2208-15. [DOI: 10.1021/ci700121z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher P. Ewels
- Institut des Matériaux Jean Rouxel, CNRS UMR6502, 2 rue de la Houssinière, 44322 Nantes, France, Laboratoire de Physique des Solides, Université Paris Sud, CNRS UMR8502, Batîment 510, 91405 Orsay, France, Research Group of General Chemistry (ALGC), Free University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels, Belgium, and Unité de Physico-Chimie et de Physique des Matériaux (P.C.P.M.), Université Catholique de Louvain (UCL), Place Croix du Sud, 1 (Boltzmann), B-1348 Louvain-la-Neuve, Belgium
| | - Gregory Van Lier
- Institut des Matériaux Jean Rouxel, CNRS UMR6502, 2 rue de la Houssinière, 44322 Nantes, France, Laboratoire de Physique des Solides, Université Paris Sud, CNRS UMR8502, Batîment 510, 91405 Orsay, France, Research Group of General Chemistry (ALGC), Free University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels, Belgium, and Unité de Physico-Chimie et de Physique des Matériaux (P.C.P.M.), Université Catholique de Louvain (UCL), Place Croix du Sud, 1 (Boltzmann), B-1348 Louvain-la-Neuve, Belgium
| | - Paul Geerlings
- Institut des Matériaux Jean Rouxel, CNRS UMR6502, 2 rue de la Houssinière, 44322 Nantes, France, Laboratoire de Physique des Solides, Université Paris Sud, CNRS UMR8502, Batîment 510, 91405 Orsay, France, Research Group of General Chemistry (ALGC), Free University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels, Belgium, and Unité de Physico-Chimie et de Physique des Matériaux (P.C.P.M.), Université Catholique de Louvain (UCL), Place Croix du Sud, 1 (Boltzmann), B-1348 Louvain-la-Neuve, Belgium
| | - Jean-Christophe Charlier
- Institut des Matériaux Jean Rouxel, CNRS UMR6502, 2 rue de la Houssinière, 44322 Nantes, France, Laboratoire de Physique des Solides, Université Paris Sud, CNRS UMR8502, Batîment 510, 91405 Orsay, France, Research Group of General Chemistry (ALGC), Free University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels, Belgium, and Unité de Physico-Chimie et de Physique des Matériaux (P.C.P.M.), Université Catholique de Louvain (UCL), Place Croix du Sud, 1 (Boltzmann), B-1348 Louvain-la-Neuve, Belgium
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41
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Ewels CP, Van Lier G, Charlier JC, Heggie MI, Briddon PR. Pattern formation on carbon nanotube surfaces. Phys Rev Lett 2006; 96:216103. [PMID: 16803255 DOI: 10.1103/physrevlett.96.216103] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Indexed: 05/10/2023]
Abstract
Calculations of fluorine binding and migration on carbon nanotube surfaces show that fluorine forms varying surface superlattices at increasing temperatures. The ordering transition is controlled by the surface migration barrier for fluorine atoms to pass through next neighbor sites on the nanotube, explaining the transition from semi-ionic low coverage to covalent high coverage fluorination observed experimentally for gas phase fluorination between 200 and 250 degrees C. The effect of solvents on fluorine binding and surface diffusion is explored.
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Affiliation(s)
- Chris P Ewels
- LPS, CNRS UMR8502, Université Paris Sud, Batîment 510, 91405 Orsay, France
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42
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Latil S, Roche S, Charlier JC. Electronic transport in carbon nanotubes with random coverage of physisorbed molecules. Nano Lett 2005; 5:2216-9. [PMID: 16277456 DOI: 10.1021/nl0514386] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The chemical sensitivity of electronic transport in carbon nanotubes under the physisorption of molecular species is investigated using a tight-binding scheme, parametrized by first-principles calculations. Such a computational method enables tackling of the complex electronic properties of chemically grafted conducting nanotubes. Our calculations demonstrate that the impact of physisorption on the transport regime critically depends on the HOMO-LUMO gap of the attached molecules. In addition, the electronic mean free path exhibits a downscaling law with a lower dependence on the coverage density of grafted molecules than for conventional substitutional doping or homogeneous disorder.
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Affiliation(s)
- Sylvain Latil
- Department of Chemistry, University of Sussex, Falmer, BN1 9QJ Brighton, United Kingdom
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43
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Endo M, Muramatsu H, Hayashi T, Kim YA, Van Lier G, Charlier JC, Terrones H, Terrones M, Dresselhaus MS. Atomic nanotube welders: boron interstitials triggering connections in double-walled carbon nanotubes. Nano Lett 2005; 5:1099-105. [PMID: 15943450 DOI: 10.1021/nl050627l] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Here we demonstrate that the incorporation of boron (B) atoms between double-walled carbon nanotubes (DWNTs) during thermal annealing (1400-1600 degrees C) results in covalent nanotube "Y" junctions, DWNT coalescence, and the formation of flattened multiwalled carbon nanotubes (MWNTs). These processes occur via the merging of adjacent tubes, which is triggered by B interstitial atoms. We observe that B atom interstitials between DWNTs are responsible for the rapid establishment of covalent connections between neighboring tubes (polymerization), thereby resulting in the fast annealing of the carbon cylinders with B atoms embedded in the newly created carbon nanotube network. Once B is in the lattice, tube faceting (polygonization) starts to occur, and the electronic properties are expected to change dramatically. Therefore, B atoms indeed act as atomic nanotube fusers (or welders), and this process could now be used in assembling novel electronic nanotube devices, nanotube networks, carbon nanofoams and heterojunctions exhibiting p-type electronic properties.
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Affiliation(s)
- Morinobu Endo
- Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano-shi 380-8553, Japan.
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44
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Van Lier G, Ewels CP, Zuliani F, De Vita A, Charlier JC. Theoretical Analysis of Fluorine Addition to Single-Walled Carbon Nanotubes: Functionalization Routes and Addition Patterns. J Phys Chem B 2005; 109:6153-8. [PMID: 16851680 DOI: 10.1021/jp046005q] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a theoretical investigation on the chemical addition patterns governing the fluorination of single wall carbon nanotubes. Monte Carlo calculations based on a Hückel model suggest that fluorination is stabilized in a bandlike pattern due to electronic confinement effects on the tube bond network topology. Ab initio analysis of the fluorination of small nanotubes show that fluorine addition along the nanotube axis direction is favored by a mechanism of carbon framework distortion. The experimentally observed formation of fluorine bands may be thus explained in terms of multiple axial C(2)F rows expanding by contiguous axial addition.
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Affiliation(s)
- Gregory Van Lier
- Unité de Physico-Chimie et de Physique des Matériaux, Université Catholique de Louvain, Place Croix du Sud, 1 Boltzmann, B-1348 Louvain-la-Neuve, Belgium.
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45
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Abstract
The orientational dependence of the interaction between two C(60) molecules is investigated using ab initio calculations. The binding energy, computed within density functional theory in the local density approximation, is substantially smaller than the one derived from the experimental heat of sublimation of fullerite, which calls into question the nature of inter-C(60) bonding. According to our calculations, the experimentally observed orientation with a C(60) presenting a hexagon-hexagon bond to a pentagonal face of the other C(60) is not really favored. Some other configurations are very close in energy and in fact a pentagon facing a pentagon and a hexagon facing a hexagon-hexagon bond are found to be slightly more favorable situations. Our results are compared to previous ones obtained either with previous empirical intermolecular potentials or to existing ab initio studies of crystalline C(60). In addition, the stacking of C(60) in a crystal and in a decahedral (C(60))(7) cluster is discussed.
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Affiliation(s)
- Florent Tournus
- Laboratoire de Physique de la Matière Condensée et Nanostructures, Université Claude Bernard-Lyon 1, 69622 Villeurbanne, France.
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46
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Dresselhaus MS, Dresselhaus G, Charlier JC, Hernández E. Electronic, thermal and mechanical properties of carbon nanotubes. Philos Trans A Math Phys Eng Sci 2004; 362:2065-2098. [PMID: 15370472 DOI: 10.1098/rsta.2004.1430] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A review of the electronic, thermal and mechanical properties of nanotubes is presented, with particular reference to properties that differ from those of the bulk counterparts and to potential applications that might result from the special structure and properties of nanotubes. Both experimental and theoretical aspects of these topics are reviewed.
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Affiliation(s)
- M S Dresselhaus
- Department of Physics and Department of Electrical Engineering and Computer Science, Massachussetts Institute of Technology, Cambridge, MA 02139-4307, USA
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47
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Abstract
Electronic quantum transport is investigated in boron- and nitrogen-doped carbon nanotubes using tight-binding methods correlated to ab initio calculations. The present technique accurately accounts for both effects of dopants, namely, charge transfer and elastic scattering. Generic transport properties such as conduction mechanisms, mean-free paths, and conductance scalings are derived for various concentration of randomly distributed boron and nitrogen dopants. Our calculations allow direct comparison with experiments and demonstrate that a small amount of dopants (<0.5%) can drastically modify the electronic transport properties of the tube, which is certainly a key effect feature for envisioning nanoelectronics.
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Affiliation(s)
- Sylvain Latil
- PCPM and CERMIN, Université Catholique de Louvain, Place Croix du Sud 1, B-1348 Louvain-la-Neuve, Belgium
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48
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Yoon M, Han S, Kim G, Lee SB, Berber S, Osawa E, Ihm J, Terrones M, Banhart F, Charlier JC, Grobert N, Terrones H, Ajayan PM, Tománek D. Zipper mechanism of nanotube fusion: theory and experiment. Phys Rev Lett 2004; 92:075504. [PMID: 14995869 DOI: 10.1103/physrevlett.92.075504] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Indexed: 05/24/2023]
Abstract
We propose a new microscopic mechanism to explain the unusually fast fusion process of carbon nanotubes. We identify the detailed pathway for two adjacent (5,5) nanotubes to gradually merge into a (10,10) tube, and characterize the transition states. The propagation of the fused region is energetically favorable and proceeds in a morphology reminiscent of a Y junction via a zipper mechanism, involving only Stone-Wales bond rearrangements with low activation barriers. The zipper mechanism of fusion is supported by a time series of high-resolution transmission electron microscopy observations.
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Affiliation(s)
- Mina Yoon
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-2320, USA
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49
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Gavillet J, Loiseau A, Journet C, Willaime F, Ducastelle F, Charlier JC. Root-growth mechanism for single-wall carbon nanotubes. Phys Rev Lett 2001; 87:275504. [PMID: 11800893 DOI: 10.1103/physrevlett.87.275504] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2000] [Indexed: 05/23/2023]
Abstract
The catalytic growth of single-wall carbon nanotubes is investigated by high-resolution transmission electron microscopy. The similarities between the samples synthesized from different techniques suggest a common growth mechanism based on a vapor-liquid-solid model. Quantum-molecular-dynamics simulations support a root growth mechanism where carbon atoms are incorporated into the tube base by a diffusion-segregation process.
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Affiliation(s)
- J Gavillet
- Laboratoire d'Etude des Microstructures (LEM), ONERA-CNRS, BP72, 92322 Châtillon Cedex, France
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50
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Abstract
Topology related changes in the local density of states near the apex of carbon nanocones are investigated using both tight-binding and ab initio calculations. Sharp resonant states are found to dominate the electronic structure in the region close to the Fermi energy. The strength and the position of these states with respect to the Fermi level depend sensitively on the number and the relative positions of the pentagons constituting the conical tip. Carbon nanocones are thus proposed as good candidates for nanoprobes in scanning probe microscopy.
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Affiliation(s)
- J C Charlier
- Unité de Physico-Chimie et de Physique des Matériaux (PCPM), Université Catholique de Louvain, Place Croix du Sud 1, B-1348 Louvain-la-Neuve, Belgium
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