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Stoodley MA, Rochford LA, Lee TL, Klein BP, Duncan DA, Maurer RJ. Structure of Graphene Grown on Cu(111): X-Ray Standing Wave Measurement and Density Functional Theory Prediction. PHYSICAL REVIEW LETTERS 2024; 132:196201. [PMID: 38804932 DOI: 10.1103/physrevlett.132.196201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 03/11/2024] [Accepted: 04/02/2024] [Indexed: 05/29/2024]
Abstract
We report the quantitative adsorption structure of pristine graphene on Cu(111) determined using the normal incidence x-ray standing wave technique. The experiments constitute an important benchmark reference for the development of density functional theory approximations able to capture long-range dispersion interactions. Electronic structure calculations based on many-body dispersion-inclusive density functional theory are able to accurately predict the absolute measure and variation of adsorption height when the coexistence of multiple moiré superstructures is considered. This provides a structural model consistent with scanning probe microscopy results.
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Affiliation(s)
- Matthew A Stoodley
- Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, United Kingdom
- Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, OX11 ODE, Didcot, United Kingdom
| | - Luke A Rochford
- Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, OX11 ODE, Didcot, United Kingdom
| | - Tien-Lin Lee
- Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, OX11 ODE, Didcot, United Kingdom
| | - Benedikt P Klein
- Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, United Kingdom
- Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, OX11 ODE, Didcot, United Kingdom
| | - David A Duncan
- Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, OX11 ODE, Didcot, United Kingdom
| | - Reinhard J Maurer
- Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, United Kingdom
- Department of Physics, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, United Kingdom
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2
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Schmitt C, Erhardt J, Eck P, Schmitt M, Lee K, Keßler P, Wagner T, Spring M, Liu B, Enzner S, Kamp M, Jovic V, Jozwiak C, Bostwick A, Rotenberg E, Kim T, Cacho C, Lee TL, Sangiovanni G, Moser S, Claessen R. Achieving environmental stability in an atomically thin quantum spin Hall insulator via graphene intercalation. Nat Commun 2024; 15:1486. [PMID: 38374074 PMCID: PMC10876696 DOI: 10.1038/s41467-024-45816-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 01/30/2024] [Indexed: 02/21/2024] Open
Abstract
Atomic monolayers on semiconductor surfaces represent an emerging class of functional quantum materials in the two-dimensional limit - ranging from superconductors and Mott insulators to ferroelectrics and quantum spin Hall insulators. Indenene, a triangular monolayer of indium with a gap of ~ 120 meV is a quantum spin Hall insulator whose micron-scale epitaxial growth on SiC(0001) makes it technologically relevant. However, its suitability for room-temperature spintronics is challenged by the instability of its topological character in air. It is imperative to develop a strategy to protect the topological nature of indenene during ex situ processing and device fabrication. Here we show that intercalation of indenene into epitaxial graphene provides effective protection from the oxidising environment, while preserving an intact topological character. Our approach opens a rich realm of ex situ experimental opportunities, priming monolayer quantum spin Hall insulators for realistic device fabrication and access to topologically protected edge channels.
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Affiliation(s)
- Cedric Schmitt
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
| | - Jonas Erhardt
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
| | - Philipp Eck
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
- Institut für Theoretische Physik und Astrophysik, Universität Würzburg, D-97074, Würzburg, Germany
| | - Matthias Schmitt
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Kyungchan Lee
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
| | - Philipp Keßler
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
| | - Tim Wagner
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
| | - Merit Spring
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
| | - Bing Liu
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
| | - Stefan Enzner
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
- Institut für Theoretische Physik und Astrophysik, Universität Würzburg, D-97074, Würzburg, Germany
| | - Martin Kamp
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Physikalisches Institut and Röntgen Center for Complex Material Systems, D-97074, Würzburg, Germany
| | - Vedran Jovic
- Earth Resources and Materials, Institute of Geological and Nuclear Science, Lower Hutt, 5010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, 6012, New Zealand
| | - Chris Jozwiak
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Aaron Bostwick
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Eli Rotenberg
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Timur Kim
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Cephise Cacho
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Tien-Lin Lee
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Giorgio Sangiovanni
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
- Institut für Theoretische Physik und Astrophysik, Universität Würzburg, D-97074, Würzburg, Germany
| | - Simon Moser
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany
| | - Ralph Claessen
- Physikalisches Institut, Universität Würzburg, D-97074, Würzburg, Germany.
- Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, D-97074, Würzburg, Germany.
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3
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Brozzesi S, Gori P, Koda DS, Bechstedt F, Pulci O. Thermodynamics and electronic structure of adsorbed and intercalated plumbene in graphene/hexagonal SiC heterostructures. Sci Rep 2024; 14:2947. [PMID: 38316818 PMCID: PMC10844374 DOI: 10.1038/s41598-024-53067-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 01/27/2024] [Indexed: 02/07/2024] Open
Abstract
Graphene-covered hexagonal SiC substrates have been frequently discussed to be appropriate starting points for epitaxial overlayers of Xenes, such as plumbene, or even their deposition as intercalates between graphene and SiC. Here, we investigate, within density functional theory, the plumbene deposition for various layer orderings and substrate terminations. By means of total energy studies we demonstrate the favorization of the intercalation versus the epitaxy for both C-terminated and Si-terminated 4H-SiC substrates. These results are explained in terms of chemical bonding and by means of layer-resolved projected band structures. Our results are compared with available experimental findings.
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Affiliation(s)
- Simone Brozzesi
- Department of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca 1, I-00133, Rome, Italy.
| | - Paola Gori
- Department of Industrial, Electronic and Mechanical Engineering, Roma Tre University, Via della Vasca Navale 79, I-00146, Rome, Italy.
| | - Daniel S Koda
- Lawrence Livermore National Laboratory, 7000 East Ave, L-367, Livermore, CA, 94551, USA
| | - Friedhelm Bechstedt
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743, Jena, Germany
| | - Olivia Pulci
- Department of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca 1, I-00133, Rome, Italy
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4
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Ichou H, Alchaar M, Baris B, Michon A, Dagher R, Dujardin E, Martrou D. Structural identification of graphene films and nanoislands on 6H-SiC(0001) by direct height measurement. NANOTECHNOLOGY 2023; 34:165703. [PMID: 36638530 DOI: 10.1088/1361-6528/acb2d0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 01/13/2023] [Indexed: 06/17/2023]
Abstract
By combining non-contact atomic force microscopy (nc-AFM) and Kelvin probe microscopy (KPFM) in ultra high vacuum environment (UHV), we directly measure the height and work function of graphene monolayer on the Si-face of 6H-SiC(0001) with a precision that allows us to differentiate three different types of graphene structures : zero layer graphene (ZLG), Quasi free-standing monolayer graphene (QFMLG) and bilayer graphene (BLG). The height and work function of ZLG are 2.62 ± 0.22 Å and 4.42 ± 0.05 eV respectively, when they are 4.09 ± 0.11 Å and 4.63 ± 0.05 eV for QFMLG. The work function is 4.83 ± 0.05 eV for the BLG. Unlike any other available technique, the local nc-AFM/KPFM dual probe makes it possible to directly identify the nature of nanometer-sized graphene islands that constitute the early nuclei of graphene monolayer grown on 6H-SiC(0001) by chemical vapor deposition.
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Affiliation(s)
- Hamza Ichou
- Centre d'Élaboration de Matériaux et d'Études Structurales (CEMES), Université de Toulouse, 29 Rue J. Marvig, BP 94347, 31055 Toulouse Cedex, France
| | - Mohanad Alchaar
- Centre d'Élaboration de Matériaux et d'Études Structurales (CEMES), Université de Toulouse, 29 Rue J. Marvig, BP 94347, 31055 Toulouse Cedex, France
| | - Bulent Baris
- Centre d'Élaboration de Matériaux et d'Études Structurales (CEMES), Université de Toulouse, 29 Rue J. Marvig, BP 94347, 31055 Toulouse Cedex, France
| | - Adrien Michon
- Université Côte d'Azur, CNRS, CRHEA, Valbonne F-06560, France
| | - Roy Dagher
- Université Côte d'Azur, CNRS, CRHEA, Valbonne F-06560, France
| | - Erik Dujardin
- Centre d'Élaboration de Matériaux et d'Études Structurales (CEMES), Université de Toulouse, 29 Rue J. Marvig, BP 94347, 31055 Toulouse Cedex, France
| | - David Martrou
- Centre d'Élaboration de Matériaux et d'Études Structurales (CEMES), Université de Toulouse, 29 Rue J. Marvig, BP 94347, 31055 Toulouse Cedex, France
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5
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Grossmann L, Duncan DA, Jarvis SP, Jones RG, De S, Rosen J, Schmittel M, Heckl WM, Björk J, Lackinger M. Evolution of adsorption heights in the on-surface synthesis and decoupling of covalent organic networks on Ag(111) by normal-incidence X-ray standing wave. NANOSCALE HORIZONS 2021; 7:51-62. [PMID: 34889932 DOI: 10.1039/d1nh00486g] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Structural characterization in on-surface synthesis is primarily carried out by Scanning Probe Microscopy (SPM) which provides high lateral resolution. Yet, important fresh perspectives on surface interactions and molecular conformations are gained from adsorption heights that remain largely inaccessible to SPM, but can be precisely measured with both elemental and chemical sensitivity by Normal-Incidence X-ray Standing Wave (NIXSW) analysis. Here, we study the evolution of adsorption heights in the on-surface synthesis and post-synthetic decoupling of porous covalent triazine-phenylene networks obtained from 2,4,6-tris(4-bromophenyl)-1,3,5-triazine (TBPT) precursors on Ag(111). Room temperature deposition of TBPT and mild annealing to ∼150 °C result in full debromination and formation of organometallic intermediates, where the monomers are linked into reticulated networks by C-Ag-C bonds. Topologically identical covalent networks comprised of triazine vertices that are interconnected by biphenyl units are obtained by a thermally activated chemical transformation of the organometallic intermediates. Exposure to iodine vapor facilitates decoupling by intercalation of an iodine monolayer between the covalent networks and the Ag(111) surface. Accordingly, Scanning Tunneling Microscopy (STM), X-ray Photoelectron Spectroscopy (XPS) and NIXSW experiments are carried out for three successive sample stages: organometallic intermediates, covalent networks directly on Ag(111) and after decoupling. NIXSW analysis facilitates the determination of adsorption heights of chemically distinct carbon species, i.e. in the phenyl and triazine rings, and also for the organometallic carbon atoms. Thereby, molecular conformations are assessed for each sample stage. The interpretation of experimental results is informed by Density Functional Theory (DFT) calculations, providing a consistent picture of adsorption heights and molecular deformations in the networks that result from the interplay between steric hindrance and surface interactions. Quantitative adsorption heights, i.e. vertical distances between adsorbates and surface, provide detailed insight into surface interactions, but are underexplored in on-surface synthesis. In particular, the direct comparison with an in situ prepared decoupled state unveils the surface influence on the network structure, and shows that iodine intercalation is a powerful decoupling strategy.
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Affiliation(s)
- Lukas Grossmann
- Deutsches Museum, Museumsinsel 1, 80538 München, Germany.
- Technische Universität München, Physics Department, James-Franck-Strasse 1, 85748 Garching, Germany
| | - David A Duncan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0QX, UK
| | - Samuel P Jarvis
- Lancaster University, Physics Department, Lancaster LA1 4YB, UK
| | - Robert G Jones
- University of Nottingham, Department of Physical Chemistry, School of Chemistry, Nottingham NG7 2RD, UK
| | - Soumen De
- Center of Micro and Nanochemistry and Engineering, Organische Chemie I, Universität Siegen, Adolf-Reichwein-Str. 2, 57068 Siegen, Germany
| | - Johanna Rosen
- Linköping University, Department of Physics, Chemistry and Biology, IFM, 581 83 Linköping, Sweden
| | - Michael Schmittel
- Center of Micro and Nanochemistry and Engineering, Organische Chemie I, Universität Siegen, Adolf-Reichwein-Str. 2, 57068 Siegen, Germany
| | - Wolfgang M Heckl
- Deutsches Museum, Museumsinsel 1, 80538 München, Germany.
- Technische Universität München, Physics Department, James-Franck-Strasse 1, 85748 Garching, Germany
| | - Jonas Björk
- Linköping University, Department of Physics, Chemistry and Biology, IFM, 581 83 Linköping, Sweden
| | - Markus Lackinger
- Deutsches Museum, Museumsinsel 1, 80538 München, Germany.
- Technische Universität München, Physics Department, James-Franck-Strasse 1, 85748 Garching, Germany
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6
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Bocquet FC, Lin YR, Franke M, Samiseresht N, Parhizkar S, Soubatch S, Lee TL, Kumpf C, Tautz FS. Surfactant-Mediated Epitaxial Growth of Single-Layer Graphene in an Unconventional Orientation on SiC. PHYSICAL REVIEW LETTERS 2020; 125:106102. [PMID: 32955317 DOI: 10.1103/physrevlett.125.106102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/08/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
We report the use of a surfactant molecule during the epitaxy of graphene on SiC(0001) that leads to the growth in an unconventional orientation, namely R0° rotation with respect to the SiC lattice. It yields a very high-quality single-layer graphene with a uniform orientation with respect to the substrate, on the wafer scale. We find an increased quality and homogeneity compared to the approach based on the use of a preoriented template to induce the unconventional orientation. Using spot profile analysis low-energy electron diffraction, angle-resolved photoelectron spectroscopy, and the normal incidence x-ray standing wave technique, we assess the crystalline quality and coverage of the graphene layer. Combined with the presence of a covalently bound graphene layer in the conventional orientation underneath, our surfactant-mediated growth offers an ideal platform to prepare epitaxial twisted bilayer graphene via intercalation.
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Affiliation(s)
- F C Bocquet
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - Y-R Lin
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - M Franke
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - N Samiseresht
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - S Parhizkar
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - S Soubatch
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - T-L Lee
- Diamond Light Source, Ltd., Didcot OX110DE, Oxfordshire, United Kingdom
| | - C Kumpf
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - F S Tautz
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
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7
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Dedkov Y, Voloshina E. Epitaxial graphene/Ge interfaces: a minireview. NANOSCALE 2020; 12:11416-11426. [PMID: 32458957 DOI: 10.1039/d0nr00185f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The recent discovery of the ability to perform direct epitaxial growth of graphene layers on semiconductor Ge surfaces led to a huge interest in this topic. One of the reasons for this interest is the chance to overcome several present-day drawbacks on the method of graphene integration in modern semiconductor technology. The other one is connected with the fundamental studies of the new graphene-semiconductor interfaces that might help with the deeper understanding of mechanisms, which governs graphene growth on different substrates as well as shedding light on the interaction of graphene with these substrates, whose range is now spread from metals to insulators. The present minireview gives a timely overview of the state-of-the-art field of studies of the graphene-Ge epitaxial interfaces and draws some conclusions in this research area.
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Affiliation(s)
- Yuriy Dedkov
- Department of Physics, Shanghai University, 200444 Shanghai, P. R. China. and Institute of Physical and Organic Chemistry, Southern Federal University, 344090 Rostov on Don, Russia
| | - Elena Voloshina
- Department of Physics, Shanghai University, 200444 Shanghai, P. R. China. and Institute of Physical and Organic Chemistry, Southern Federal University, 344090 Rostov on Don, Russia
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Franco-Cañellas A, Duhm S, Gerlach A, Schreiber F. Binding and electronic level alignment of π-conjugated systems on metals. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2020; 83:066501. [PMID: 32101802 DOI: 10.1088/1361-6633/ab7a42] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We review the binding and energy level alignment of π-conjugated systems on metals, a field which during the last two decades has seen tremendous progress both in terms of experimental characterization as well as in the depth of theoretical understanding. Precise measurements of vertical adsorption distances and the electronic structure together with ab initio calculations have shown that most of the molecular systems have to be considered as intermediate cases between weak physisorption and strong chemisorption. In this regime, the subtle interplay of different effects such as covalent bonding, charge transfer, electrostatic and van der Waals interactions yields a complex situation with different adsorption mechanisms. In order to establish a better understanding of the binding and the electronic level alignment of π-conjugated molecules on metals, we provide an up-to-date overview of the literature, explain the fundamental concepts as well as the experimental techniques and discuss typical case studies. Thereby, we relate the geometric with the electronic structure in a consistent picture and cover the entire range from weak to strong coupling.
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Affiliation(s)
- Antoni Franco-Cañellas
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
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9
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Niu T, Meng Q, Zhou D, Si N, Zhai S, Hao X, Zhou M, Fuchs H. Large-Scale Synthesis of Strain-Tunable Semiconducting Antimonene on Copper Oxide. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1906873. [PMID: 31825535 DOI: 10.1002/adma.201906873] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 11/26/2019] [Indexed: 06/10/2023]
Abstract
Controlled synthesis of 2D structures on nonmetallic substrate is challenging, yet an attractive approach for the integration of 2D systems into current semiconductor technologies. Herein, the direct synthesis of high-quality 2D antimony, or antimonene, on dielectric copper oxide substrate by molecular beam epitaxy is reported. Delicate scanning tunneling microscopy imaging on the evolution intermediates reveals a segregation growth process on Cu3 O2 /Cu(111), from ordered dimer chains to packed dot arrays, and finally to monolayer antimonene. First-principles calculations demonstrate the strain-modulated band structures in antimonene, which interacts weakly with the oxide surface so that its semiconducting nature is preserved, in perfect agreement with spectroscopic measurements. This work paves the way for large-scale growth and processing of antimonene for practical implementation.
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Affiliation(s)
- Tianchao Niu
- Herbert Gleiter Institute of Nanoscience, School of Material Science and Engineering, Nanjing University of Science & Technology, Nanjing, 210094, China
| | - Qingling Meng
- School of Physics, Beihang University, Beijing, 100191, China
| | - Dechun Zhou
- Herbert Gleiter Institute of Nanoscience, School of Material Science and Engineering, Nanjing University of Science & Technology, Nanjing, 210094, China
| | - Nan Si
- Herbert Gleiter Institute of Nanoscience, School of Material Science and Engineering, Nanjing University of Science & Technology, Nanjing, 210094, China
| | - Shuwei Zhai
- School of Physics, Beihang University, Beijing, 100191, China
| | - Xiamin Hao
- School of Physics, Beihang University, Beijing, 100191, China
| | - Miao Zhou
- School of Physics, Beihang University, Beijing, 100191, China
| | - Harald Fuchs
- Herbert Gleiter Institute of Nanoscience, School of Material Science and Engineering, Nanjing University of Science & Technology, Nanjing, 210094, China
- Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, Münster, 48149, Germany
- Center for Nanotechnology (CeNTech), Westfälische Wilhelms-Universität Münster, Heisenbergstrasse 11, Münster, 48149, Germany
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10
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Huelmo CP, Denis PA. Unraveling the electromagnetic structure of the epitaxial graphene buffer layer. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:435001. [PMID: 31269473 DOI: 10.1088/1361-648x/ab2ee2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have employed density functional theory to study the structural, electronic and magnetic properties of the first all-carbon layer grown epitaxially on 6H-SiC(0 0 0 1). Using VDW-DF, M06-L, LSDA, LSDA+U, PBE and PBE-D2 methods we have performed a comparative study of the preferable magnetic configuration of the system. In this work, for the first time, we report a stable antiferromagnetic (AF) ordering in the buffer layer caused by the presence of silicon dangling bonds in the SiC top layer. This state is nearly degenerated with the ferromagnetic state with a magnetic moment equal to the number of silicon dangling bonds. A net magnetic moment of 0.55 µb per Si dangling bond was found for both states. However, only for the ferromagnetic state the carbon atoms of the buffer layer exhibited a magnetic moment. The magnetic configuration is much more stable than the non-polarized one and might explain SQUID results and spin transport experiments with epitaxial graphene. Furthermore, we found that, as previously observed experimentally, the buffer layer is a true semiconductor.
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Affiliation(s)
- C Pereyra Huelmo
- Facultad de Química, Computational Nanotechnology, DETEMA, UDELAR, CC 1157, 11800 Montevideo, Uruguay
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11
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Balog R, Cassidy A, Jørgensen J, Kyhl L, Andersen M, Čabo AG, Ravani F, Bignardi L, Lacovig P, Lizzit S, Hornekær L. Hydrogen interaction with graphene on Ir(1 1 1): a combined intercalation and functionalization study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:085001. [PMID: 30628585 DOI: 10.1088/1361-648x/aaf76b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We demonstrate a procedure for obtaining a H-intercalated graphene layer that is found to be chemically decoupled from the underlying metal substrate. Using high-resolution x-ray photoelectron spectroscopy and scanning tunneling microscopy techniques, we reveal that the hydrogen intercalated graphene is p-doped by about 0.28 eV, but also identify structures of interfacial hydrogen. Furthermore, we investigate the reactivity of the decoupled layer towards atomic hydrogen and vibrationally excited molecular hydrogen and compare these results to the case of non-intercalated graphene. We find distinct differences between the two. Finally, we discuss the possibility to form graphane clusters on an iridium substrate by combined intercalation and H atom exposure experiments.
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Affiliation(s)
- Richard Balog
- Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark
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12
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Cho S, Kim BS, Kim B, Kyung W, Seo J, Park M, Jeon JW, Tanaka K, Denlinger JD, Kim C, Odkhuu D, Kim BH, Park SR. Electronic-dimensionality reduction of bulk MoS 2 by hydrogen treatment. Phys Chem Chem Phys 2018; 20:23007-23012. [PMID: 30159559 DOI: 10.1039/c8cp02365d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A reduction in the electronic-dimensionality of materials is one method for achieving improvements in material properties. Here, a reduction in electronic-dimensionality is demonstrated using a simple hydrogen treatment technique. Quantum well states from hydrogen-treated bulk 2H-MoS2 are observed using angle resolved photoemission spectroscopy (ARPES). The electronic states are confined within a few MoS2 layers after the hydrogen treatment. A significant reduction in the band-gap can also be achieved after the hydrogen treatment, and both phenomena can be explained by the formation of sulfur vacancies generated by the chemical reaction between sulfur and hydrogen.
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Affiliation(s)
- Soohyun Cho
- Institute of Physics and Applied Physics, Yonsei University, Seoul, 03722, Korea
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13
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Cavallucci T, Tozzini V. Intrinsic structural and electronic properties of the Buffer Layer on Silicon Carbide unraveled by Density Functional Theory. Sci Rep 2018; 8:13097. [PMID: 30166596 PMCID: PMC6117312 DOI: 10.1038/s41598-018-31490-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/15/2018] [Indexed: 11/09/2022] Open
Abstract
The buffer carbon layer obtained in the first instance by evaporation of Si from the Si-rich surfaces of silicon carbide (SiC) is often studied only as the intermediate to the synthesis of SiC supported graphene. In this work, we explore its intrinsic potentialities, addressing its structural and electronic properties by means of Density Functional Theory. While the system of corrugation crests organized in a honeycomb super-lattice of nano-metric side returned by calculations is compatible with atomic microscopy observations, our work reveals some possible alternative symmetries, which might coexist in the same sample. The electronic structure analysis reveals the presence of an electronic gap of ~0.7 eV. In-gap states are present, localized over the crests, while near-gap states reveal very different structure and space localization, being either bonding states or outward pointing p orbitals and unsaturated Si dangling bonds. On one hand, the presence of these interface states was correlated with the n-doping of the monolayer graphene subsequently grown on the buffer. On the other hand, the correlation between their chemical character and their space localization is likely to produce a differential reactivity towards specific functional groups with a spatial regular modulation at the nano-scale, opening perspectives for a finely controlled chemical functionalization.
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Affiliation(s)
- Tommaso Cavallucci
- Istituto Nanoscienze, Cnr, Piazza San Silvestro 12, 56127, Pisa, Italy.,NEST- Scuola Normale Superiore Piazza San Silvestro 12, 56127, Pisa, Italy
| | - Valentina Tozzini
- Istituto Nanoscienze, Cnr, Piazza San Silvestro 12, 56127, Pisa, Italy. .,NEST- Scuola Normale Superiore Piazza San Silvestro 12, 56127, Pisa, Italy.
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14
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Lee TL, Duncan DA. A Two-Color Beamline for Electron Spectroscopies at Diamond Light Source. ACTA ACUST UNITED AC 2018. [DOI: 10.1080/08940886.2018.1483653] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Tien-Lin Lee
- Diamond Light Source Ltd., Didcot, Oxfordshire, UK
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15
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Amjadipour M, Tadich A, Boeckl JJ, Lipton-Duffin J, MacLeod J, Iacopi F, Motta N. Quasi free-standing epitaxial graphene fabrication on 3C-SiC/Si(111). NANOTECHNOLOGY 2018; 29:145601. [PMID: 29376834 DOI: 10.1088/1361-6528/aaab1a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Growing graphene on SiC thin films on Si is a cheaper alternative to the growth on bulk SiC, and for this reason it has been recently intensively investigated. Here we study the effect of hydrogen intercalation on epitaxial graphene obtained by high temperature annealing on 3C-SiC/Si(111) in ultra-high vacuum. By using a combination of core-level photoelectron spectroscopy, low energy electron diffraction, and near-edge x-ray absorption fine structure (NEXAFS) we find that hydrogen saturates the Si atoms at the topmost layer of the substrate, leading to free-standing graphene on 3C-SiC/Si(111). The intercalated hydrogen fully desorbs after heating the sample at 850 °C and the buffer layer appears again, similar to what has been reported for bulk SiC. However, the NEXAFS analysis sheds new light on the effect of hydrogen intercalation, showing an improvement of graphene's flatness after annealing in atomic H at 600 °C. These results provide new insight into free-standing graphene fabrication on SiC/Si thin films.
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Affiliation(s)
- Mojtaba Amjadipour
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, QLD, Australia
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16
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Deposition of topological silicene, germanene and stanene on graphene-covered SiC substrates. Sci Rep 2017; 7:15700. [PMID: 29146916 PMCID: PMC5691050 DOI: 10.1038/s41598-017-15610-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/30/2017] [Indexed: 11/09/2022] Open
Abstract
Growth of X-enes, such as silicene, germanene and stanene, requires passivated substrates to ensure the survival of their exotic properties. Using first-principles methods, we study as-grown graphene on polar SiC surfaces as suitable substrates. Trilayer combinations with coincidence lattices with large hexagonal unit cells allow for strain-free group-IV monolayers. In contrast to the Si-terminated SiC surface, van der Waals-bonded honeycomb X-ene/graphene bilayers on top of the C-terminated SiC substrate are stable. Folded band structures show Dirac cones of the overlayers with small gaps of about 0.1 eV in between. The topological invariants of the peeled-off X-ene/graphene bilayers indicate the presence of topological character and the existence of a quantum spin Hall phase.
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17
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Liu K, Yan P, Li J, He C, Ouyang T, Zhang C, Tang C, Zhong J. Effect of hydrogen passivation on the decoupling of graphene on SiC(0001) substrate: First-principles calculations. Sci Rep 2017; 7:8461. [PMID: 28814766 PMCID: PMC5559521 DOI: 10.1038/s41598-017-09161-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 07/21/2017] [Indexed: 11/09/2022] Open
Abstract
Intercalation of hydrogen is important for understanding the decoupling of graphene from SiC(0001) substrate. Employing first-principles calculations, we have systematically studied the decoupling of graphene from SiC surface by H atoms intercalation from graphene boundary. It is found the passivation of H atoms on both graphene edge and SiC substrate is the key factor of the decoupling process. Passivation of graphene edge can weaken the interaction between graphene boundary and the substrate, which reduced the energy barrier significantly for H diffusion into the graphene-SiC interface. As more and more H atoms diffuse into the interface and saturate the Si dangling bonds around the boundary, graphene will detach from substrate. Furthermore, the energy barriers in these processes are relatively low, indicating that these processes can occur under the experimental temperature.
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Affiliation(s)
- Kang Liu
- Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan, 411105, P. R. China.,Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China
| | - Pinglan Yan
- Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan, 411105, P. R. China.,Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China
| | - Jin Li
- Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan, 411105, P. R. China. .,Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China.
| | - Chaoyu He
- Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan, 411105, P. R. China.,Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China
| | - Tao Ouyang
- Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan, 411105, P. R. China.,Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China
| | - Chunxiao Zhang
- Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan, 411105, P. R. China.,Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China
| | - Chao Tang
- Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan, 411105, P. R. China. .,Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China.
| | - Jianxin Zhong
- Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan, 411105, P. R. China.,Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China
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18
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Fortin-Deschênes M, Waller O, Menteş TO, Locatelli A, Mukherjee S, Genuzio F, Levesque PL, Hébert A, Martel R, Moutanabbir O. Synthesis of Antimonene on Germanium. NANO LETTERS 2017; 17:4970-4975. [PMID: 28678509 DOI: 10.1021/acs.nanolett.7b02111] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The lack of large-area synthesis processes on substrates compatible with industry requirements has been one of the major hurdles facing the integration of 2D materials in mainstream technologies. This is particularly the case for the recently discovered monoelemental group V 2D materials which can only be produced by exfoliation or growth on exotic substrates. Herein, to overcome this limitation, we demonstrate a scalable method to synthesize antimonene on germanium substrates using solid-source molecular beam epitaxy. This emerging 2D material has been attracting a great deal of attention due to its high environmental stability and its outstanding optical and electronic properties. In situ low energy electron microscopy allowed the real time investigation and optimization of the 2D growth. Theoretical calculations combined with atomic-scale microscopic and spectroscopic measurements demonstrated that the grown antimonene sheets are of high crystalline quality, interact weakly with germanium, exhibit semimetallic characteristics, and remain stable under ambient conditions. This achievement paves the way for the integration of antimonene in innovative nanoscale and quantum technologies compatible with the current semiconductor manufacturing.
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Affiliation(s)
- M Fortin-Deschênes
- Department of Engineering Physics, École Polytechnique de Montréal , C. P. 6079, Succ. Centre-Ville, Montréal, Québec H3C 3A7, Canada
| | - O Waller
- Department of Engineering Physics, École Polytechnique de Montréal , C. P. 6079, Succ. Centre-Ville, Montréal, Québec H3C 3A7, Canada
| | - T O Menteş
- Elettra-Sincrotrone Trieste S.C.p.A. , S.S. 14 - km 163, 5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - A Locatelli
- Elettra-Sincrotrone Trieste S.C.p.A. , S.S. 14 - km 163, 5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - S Mukherjee
- Department of Engineering Physics, École Polytechnique de Montréal , C. P. 6079, Succ. Centre-Ville, Montréal, Québec H3C 3A7, Canada
| | - F Genuzio
- Elettra-Sincrotrone Trieste S.C.p.A. , S.S. 14 - km 163, 5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - P L Levesque
- Département de Chimie, Université de Montréal , 2900 boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
| | - A Hébert
- Department of Engineering Physics, École Polytechnique de Montréal , C. P. 6079, Succ. Centre-Ville, Montréal, Québec H3C 3A7, Canada
| | - R Martel
- Département de Chimie, Université de Montréal , 2900 boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
| | - O Moutanabbir
- Department of Engineering Physics, École Polytechnique de Montréal , C. P. 6079, Succ. Centre-Ville, Montréal, Québec H3C 3A7, Canada
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19
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Farwick Zum Hagen FH, Zimmermann DM, Silva CC, Schlueter C, Atodiresei N, Jolie W, Martínez-Galera AJ, Dombrowski D, Schröder UA, Will M, Lazić P, Caciuc V, Blügel S, Lee TL, Michely T, Busse C. Structure and Growth of Hexagonal Boron Nitride on Ir(111). ACS NANO 2016; 10:11012-11026. [PMID: 28024332 DOI: 10.1021/acsnano.6b05819] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Using the X-ray standing wave method, scanning tunneling microscopy, low energy electron diffraction, and density functional theory, we precisely determine the lateral and vertical structure of hexagonal boron nitride on Ir(111). The moiré superstructure leads to a periodic arrangement of strongly chemisorbed valleys in an otherwise rather flat, weakly physisorbed plane. The best commensurate approximation of the moiré unit cell is (12 × 12) boron nitride cells resting on (11 × 11) substrate cells, which is at variance with several earlier studies. We uncover the existence of two fundamentally different mechanisms of layer formation for hexagonal boron nitride, namely, nucleation and growth as opposed to network formation without nucleation. The different pathways are linked to different distributions of rotational domains, and the latter enables selection of a single orientation only.
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Affiliation(s)
| | - Domenik M Zimmermann
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Caio C Silva
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
- Institut für Materialphysik, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | | | - Nicolae Atodiresei
- Peter Grünberg Institut (PGI) and Institute for Advanced Simulation (IAS), Forschungszentrum Jülich and JARA , 52425 Jülich, Germany
| | - Wouter Jolie
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | | | - Daniela Dombrowski
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
- Institut für Materialphysik, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Ulrike A Schröder
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Moritz Will
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Predrag Lazić
- Institut Ruđer Bošković , Bijenička 54, 10000 Zagreb, Croatia
| | - Vasile Caciuc
- Peter Grünberg Institut (PGI) and Institute for Advanced Simulation (IAS), Forschungszentrum Jülich and JARA , 52425 Jülich, Germany
| | - Stefan Blügel
- Peter Grünberg Institut (PGI) and Institute for Advanced Simulation (IAS), Forschungszentrum Jülich and JARA , 52425 Jülich, Germany
| | | | - Thomas Michely
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Carsten Busse
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
- Institut für Materialphysik, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
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20
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Tu Q, Lange B, Parlak Z, Lopes JMJ, Blum V, Zauscher S. Quantitative Subsurface Atomic Structure Fingerprint for 2D Materials and Heterostructures by First-Principles-Calibrated Contact-Resonance Atomic Force Microscopy. ACS NANO 2016; 10:6491-6500. [PMID: 27263541 DOI: 10.1021/acsnano.6b02402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Interfaces and subsurface layers are critical for the performance of devices made of 2D materials and heterostructures. Facile, nondestructive, and quantitative ways to characterize the structure of atomically thin, layered materials are thus essential to ensure control of the resultant properties. Here, we show that contact-resonance atomic force microscopy-which is exquisitely sensitive to stiffness changes that arise from even a single atomic layer of a van der Waals-adhered material-is a powerful experimental tool to address this challenge. A combined density functional theory and continuum modeling approach is introduced that yields sub-surface-sensitive, nanomechanical fingerprints associated with specific, well-defined structure models of individual surface domains. Where such models are known, this information can be correlated with experimentally obtained contact-resonance frequency maps to reveal the (sub)surface structure of different domains on the sample.
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Affiliation(s)
- Qing Tu
- Department of Mechanical Engineering and Materials Science, Duke University , Durham, North Carolina 27708, United States
| | - Björn Lange
- Department of Mechanical Engineering and Materials Science, Duke University , Durham, North Carolina 27708, United States
| | - Zehra Parlak
- Department of Mechanical Engineering and Materials Science, Duke University , Durham, North Carolina 27708, United States
| | - Joao Marcelo J Lopes
- Paul-Drude-Institut für Festkörperelektronik , Hausvogteiplatz 5-7, D-10117 Berlin, Germany
| | - Volker Blum
- Department of Mechanical Engineering and Materials Science, Duke University , Durham, North Carolina 27708, United States
| | - Stefan Zauscher
- Department of Mechanical Engineering and Materials Science, Duke University , Durham, North Carolina 27708, United States
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21
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Jung SW, Shin WJ, Kim J, Moreschini L, Yeom HW, Rotenberg E, Bostwick A, Kim KS. Sublattice Interference as the Origin of σ Band Kinks in Graphene. PHYSICAL REVIEW LETTERS 2016; 116:186802. [PMID: 27203340 DOI: 10.1103/physrevlett.116.186802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Indexed: 06/05/2023]
Abstract
Kinks near the Fermi level observed in angle-resolved photoemission spectroscopy (ARPES) have been widely accepted to represent electronic coupling to collective excitations, but kinks at higher energies have eluded a unified description. We identify the mechanism leading to such kink features by means of ARPES and tight-binding band calculations on σ bands of graphene, where anomalous kinks at energies as high as ∼4 eV were reported recently [Phys. Rev. Lett. 111, 216806 (2013)]. We found that two σ bands show a strong intensity modulation with abruptly vanishing intensity near the kink features, which is due to sublattice interference. The interference induced local singularity in the matrix element is a critical factor that gives rise to apparent kink features, as confirmed by our spectral simulations without involving any coupling to collective excitations.
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Affiliation(s)
- Sung Won Jung
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Woo Jong Shin
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Jimin Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Luca Moreschini
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 37673, Korea
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Eli Rotenberg
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Aaron Bostwick
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Keun Su Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang 37673, Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
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22
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Ondarçuhu T, Thomas V, Nuñez M, Dujardin E, Rahman A, Black CT, Checco A. Wettability of partially suspended graphene. Sci Rep 2016; 6:24237. [PMID: 27072195 PMCID: PMC4829856 DOI: 10.1038/srep24237] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/22/2016] [Indexed: 11/18/2022] Open
Abstract
The dependence of the wettability of graphene on the nature of the underlying substrate remains only partially understood. Here, we systematically investigate the role of liquid-substrate interactions on the wettability of graphene by varying the area fraction of suspended graphene from 0 to 95% by means of nanotextured substrates. We find that completely suspended graphene exhibits the highest water contact angle (85° ± 5°) compared to partially suspended or supported graphene, regardless of the hydrophobicity (hydrophilicity) of the substrate. Further, 80% of the long-range water-substrate interactions are screened by the graphene monolayer, the wettability of which is primarily determined by short-range graphene-liquid interactions. By its well-defined chemical and geometrical properties, supported graphene therefore provides a model system to elucidate the relative contribution of short and long range interactions to the macroscopic contact angle.
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Affiliation(s)
- Thierry Ondarçuhu
- Nanosciences group, CEMES-CNRS, 29 rue Jeanne Marvig, Toulouse 31055, France
| | - Vincent Thomas
- Nanosciences group, CEMES-CNRS, 29 rue Jeanne Marvig, Toulouse 31055, France
| | - Marc Nuñez
- Nanosciences group, CEMES-CNRS, 29 rue Jeanne Marvig, Toulouse 31055, France
| | - Erik Dujardin
- Nanosciences group, CEMES-CNRS, 29 rue Jeanne Marvig, Toulouse 31055, France
| | - Atikur Rahman
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Charles T Black
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Antonio Checco
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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23
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Sforzini J, Hapala P, Franke M, van Straaten G, Stöhr A, Link S, Soubatch S, Jelínek P, Lee TL, Starke U, Švec M, Bocquet FC, Tautz FS. Structural and Electronic Properties of Nitrogen-Doped Graphene. PHYSICAL REVIEW LETTERS 2016; 116:126805. [PMID: 27058093 DOI: 10.1103/physrevlett.116.126805] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Indexed: 06/05/2023]
Abstract
We investigate the structural and electronic properties of nitrogen-doped epitaxial monolayer graphene and quasifreestanding monolayer graphene on 6H-SiC(0001) by the normal incidence x-ray standing wave technique and by angle-resolved photoelectron spectroscopy supported by density functional theory simulations. With the location of various nitrogen species uniquely identified, we observe that for the same doping procedure, the graphene support, consisting of substrate and interface, strongly influences the structural as well as the electronic properties of the resulting doped graphene layer. Compared to epitaxial graphene, quasifreestanding graphene is found to contain fewer nitrogen dopants. However, this lack of dopants is compensated by the proximity of nitrogen atoms at the interface that yield a similar number of charge carriers in graphene.
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Affiliation(s)
- J Sforzini
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - P Hapala
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague, Czech Republic
| | - M Franke
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - G van Straaten
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - A Stöhr
- Max Planck Institute for Solid State Research, Heisenbergstraße, 70569 Stuttgart, Germany
| | - S Link
- Max Planck Institute for Solid State Research, Heisenbergstraße, 70569 Stuttgart, Germany
| | - S Soubatch
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - P Jelínek
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague, Czech Republic
| | - T-L Lee
- Diamond Light Source Ltd, Didcot OX110DE, Oxfordshire, United Kingdom
| | - U Starke
- Max Planck Institute for Solid State Research, Heisenbergstraße, 70569 Stuttgart, Germany
| | - M Švec
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague, Czech Republic
| | - F C Bocquet
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - F S Tautz
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
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24
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Whitener KE, Lee WK, Bassim ND, Stroud RM, Robinson JT, Sheehan PE. Transfer of Chemically Modified Graphene with Retention of Functionality for Surface Engineering. NANO LETTERS 2016; 16:1455-1461. [PMID: 26784372 DOI: 10.1021/acs.nanolett.5b05073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Single-layer graphene chemically reduced by the Birch process delaminates from a Si/SiOx substrate when exposed to an ethanol/water mixture, enabling transfer of chemically functionalized graphene to arbitrary substrates such as metals, dielectrics, and polymers. Unlike in previous reports, the graphene retains hydrogen, methyl, and aryl functional groups during the transfer process. This enables one to functionalize the receiving substrate with the properties of the chemically modified graphene (CMG). For instance, magnetic force microscopy shows that the previously reported magnetic properties of partially hydrogenated graphene remain after transfer. We also transfer hydrogenated graphene from its copper growth substrate to a Si/SiOx wafer and thermally dehydrogenate it to demonstrate a polymer- and etchant-free graphene transfer for potential use in transmission electron microscopy. Finally, we show that the Birch reduction facilitates delamination of CMG by weakening van der Waals forces between graphene and its substrate.
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Affiliation(s)
- Keith E Whitener
- Chemistry Division, ‡Materials Science and Technology Division, and §Electronic Science and Technology Division, U.S. Naval Research Laboratory , Washington, D.C. 20375, United States
| | - Woo-Kyung Lee
- Chemistry Division, ‡Materials Science and Technology Division, and §Electronic Science and Technology Division, U.S. Naval Research Laboratory , Washington, D.C. 20375, United States
| | - Nabil D Bassim
- Chemistry Division, ‡Materials Science and Technology Division, and §Electronic Science and Technology Division, U.S. Naval Research Laboratory , Washington, D.C. 20375, United States
| | - Rhonda M Stroud
- Chemistry Division, ‡Materials Science and Technology Division, and §Electronic Science and Technology Division, U.S. Naval Research Laboratory , Washington, D.C. 20375, United States
| | - Jeremy T Robinson
- Chemistry Division, ‡Materials Science and Technology Division, and §Electronic Science and Technology Division, U.S. Naval Research Laboratory , Washington, D.C. 20375, United States
| | - Paul E Sheehan
- Chemistry Division, ‡Materials Science and Technology Division, and §Electronic Science and Technology Division, U.S. Naval Research Laboratory , Washington, D.C. 20375, United States
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25
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Nigam S, Majumder C, Pandey R. Impact of van der Waal’s interaction in the hybrid bilayer of silicene/SiC. RSC Adv 2016. [DOI: 10.1039/c6ra00225k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
DFT calculations find a noticeable interlayer van der Waal interaction in a silicene/SiC hybrid bilayer. The interaction leads to curvature in the planar SiC sheet and opens the band gap of the silicene sheet.
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Affiliation(s)
- Sandeep Nigam
- Chemistry Division
- Bhabha Atomic Research Centre
- Mumbai
- India
| | | | - Ravindra Pandey
- Department of Physics
- Michigan Technological University
- Houghton
- USA
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