1
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Shiffa M, Dewes BT, Bradford J, Cottam ND, Cheng TS, Mellor CJ, Makarovskiy O, Rahman K, O'Shea JN, Beton PH, Novikov SV, Ben T, Gonzalez D, Xie J, Zhang L, Patanè A. Wafer-Scale Two-Dimensional Semiconductors for Deep UV Sensing. Small 2024; 20:e2305865. [PMID: 37798672 DOI: 10.1002/smll.202305865] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/29/2023] [Indexed: 10/07/2023]
Abstract
2D semiconductors (2SEM) can transform many sectors, from information and communication technology to healthcare. To date, top-down approaches to their fabrication, such as exfoliation of bulk crystals by "scotch-tape," are widely used, but have limited prospects for precise engineering of functionalities and scalability. Here, a bottom-up technique based on epitaxy is used to demonstrate high-quality, wafer-scale 2SEM based on the wide band gap gallium selenide (GaSe) compound. GaSe layers of well-defined thickness are developed using a bespoke facility for the epitaxial growth and in situ studies of 2SEM. The dominant centrosymmetry and stacking of the individual van der Waals layers are verified by theory and experiment; their optical anisotropy and resonant absorption in the UV spectrum are exploited for photon sensing in the technological UV-C spectral range, offering a scalable route to deep-UV optoelectronics.
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Affiliation(s)
- Mustaqeem Shiffa
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Benjamin T Dewes
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Jonathan Bradford
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Nathan D Cottam
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Tin S Cheng
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Christopher J Mellor
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Oleg Makarovskiy
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Kazi Rahman
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - James N O'Shea
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Sergei V Novikov
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Teresa Ben
- University Research Institute on Electron Microscopy and Materials, IMEYMAT, Universidad de Cádiz, Cádiz, 11510, Spain
| | - David Gonzalez
- University Research Institute on Electron Microscopy and Materials, IMEYMAT, Universidad de Cádiz, Cádiz, 11510, Spain
| | - Jiahao Xie
- College of Materials Science and Engineering, Jilin University, Changchun, 130012, China
| | - Lijun Zhang
- College of Materials Science and Engineering, Jilin University, Changchun, 130012, China
| | - Amalia Patanè
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
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2
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Shima K, Cheng TS, Mellor CJ, Beton PH, Elias C, Valvin P, Gil B, Cassabois G, Novikov SV, Chichibu SF. Cathodoluminescence spectroscopy of monolayer hexagonal boron nitride. Sci Rep 2024; 14:169. [PMID: 38167439 PMCID: PMC10762211 DOI: 10.1038/s41598-023-50502-9] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/20/2023] [Indexed: 01/05/2024] Open
Abstract
Cathodoluminescence (CL) spectroscopy is a suitable technique for studying the luminescent properties of optoelectronic materials because CL has no limitation on the excitable bandgap energy and eliminates ambiguous signals due to simple light scattering and resonant Raman scattering potentially involved in the photoluminescence spectra. However, direct CL measurements of atomically thin two-dimensional materials have been difficult due to the small excitation volume that interacts with high-energy electron beams. Herein, distinct CL signals from a monolayer hexagonal BN (hBN), namely mBN, epitaxial film grown on a graphite substrate are shown by using a CL system capable of large-area and surface-sensitive excitation. Spatially resolved CL spectra at 13 K exhibited a predominant 5.5-eV emission band, which has been ascribed to originate from multilayered aggregates of hBN, markedly at thicker areas formed on the step edges of the substrate. Conversely, a faint peak at 6.04 ± 0.01 eV was routinely observed from atomically flat areas, which is assigned as being due to the recombination of phonon-assisted direct excitons of mBN. The CL results support the transition from indirect bandgap in bulk hBN to direct bandgap in mBN. The results also encourage one to elucidate emission properties of other low-dimensional materials by using the present CL configuration.
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Grants
- Crossover Alliance to Create the Future with People, Intelligence, and Materials Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan
- Crossover Alliance to Create the Future with People, Intelligence, and Materials Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan
- EP/K040243/1 The Engineering and Physical Sciences Research Council UK
- EP/P019080/1 The Engineering and Physical Sciences Research Council UK
- EP/V05323X/1 The Engineering and Physical Sciences Research Council UK
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Affiliation(s)
- Kohei Shima
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, 980-8577, Japan.
| | - Tin S Cheng
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Christopher J Mellor
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Christine Elias
- Laboratoire Charles Coulomb, UMR5221 CNRS, Université de Montpellier, 34095, Montpellier, France
| | - Pierre Valvin
- Laboratoire Charles Coulomb, UMR5221 CNRS, Université de Montpellier, 34095, Montpellier, France
| | - Bernard Gil
- Laboratoire Charles Coulomb, UMR5221 CNRS, Université de Montpellier, 34095, Montpellier, France
| | - Guillaume Cassabois
- Laboratoire Charles Coulomb, UMR5221 CNRS, Université de Montpellier, 34095, Montpellier, France
| | - Sergei V Novikov
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Shigefusa F Chichibu
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, 980-8577, Japan.
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3
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Austin JS, Cottam ND, Zhang C, Wang F, Gosling JH, Nelson-Dummet O, James TSS, Beton PH, Trindade GF, Zhou Y, Tuck CJ, Hague R, Makarovsky O, Turyanska L. Photosensitisation of inkjet printed graphene with stable all-inorganic perovskite nanocrystals. Nanoscale 2023; 15:2134-2142. [PMID: 36644953 DOI: 10.1039/d2nr06429d] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
All-inorganic perovskite nanocrystals (NCs) with enhanced environmental stability are of particular interest for optoelectronic applications. Here we report on the formulation of CsPbX3 (X is Br or I) inks for inkjet deposition and utilise these NCs as photosensitive layers in graphene photodetectors, including those based on single layer graphene (SLG) as well as inkjet-printed graphene (iGr) devices. The performance of these photodetectors strongly depends on the device structure, geometry and the fabrication process. We achieve a high photoresponsivity, R > 106 A W-1 in the visible wavelength range and a spectral response controlled by the halide content of the perovskite NC ink. By utilising perovskite NCs, iGr and gold nanoparticle inks, we demonstrate a fully inkjet-printed photodetector with R ≈ 20 A W-1, which is the highest value reported to date for this type of device. The performance of the perovskite/graphene photodetectors is explained by transfer of photo-generated charge carriers from the perovskite NCs into graphene and charge transport through the iGr network. The perovskite ink developed here enabled realisation of stable and sensitive graphene-based photon detectors. Compatibility of inkjet deposition with conventional Si-technologies and with flexible substrates combined with high degree of design freedom provided by inkjet deposition offers opportunities for partially and fully printed optoelectronic devices for applications ranging from electronics to environmental sciences.
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Affiliation(s)
- Jonathan S Austin
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Jubilee Campus, Nottingham, NG8 1BB, UK.
| | - Nathan D Cottam
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Chengxi Zhang
- Key Laboratory of Advanced Display and System Applications, Shanghai University, 149 Yanchang Road, 200072, China
| | - Feiran Wang
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Jubilee Campus, Nottingham, NG8 1BB, UK.
| | - Jonathan H Gosling
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Jubilee Campus, Nottingham, NG8 1BB, UK.
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Oliver Nelson-Dummet
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Jubilee Campus, Nottingham, NG8 1BB, UK.
| | - Tyler S S James
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | | | - Yundong Zhou
- National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK
| | - Christopher J Tuck
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Jubilee Campus, Nottingham, NG8 1BB, UK.
| | - Richard Hague
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Jubilee Campus, Nottingham, NG8 1BB, UK.
| | - Oleg Makarovsky
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Lyudmila Turyanska
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, Jubilee Campus, Nottingham, NG8 1BB, UK.
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4
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Liirò-Peluso L, Wrigley J, Amabilino DB, Beton PH. Submolecular Resolution Imaging of P3HT:PCBM Nanostructured Films by Atomic Force Microscopy: Implications for Organic Solar Cells. ACS Appl Nano Mater 2022; 5:13794-13804. [PMID: 36338328 PMCID: PMC9623582 DOI: 10.1021/acsanm.2c01399] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The efficiency of organic bulk-heterojunction (BHJ) solar cells depends greatly on both the bulk and surface structure of the nanostructured bicontinuous interpenetrating network of materials, known as the active layer. The morphology of the top layer of a coated film is often resolved at the scale of a few nanometers, but fine details of the domains and the order within them are more difficult to identify. Here, we report a high-resolution atomic force microscopy (AFM) investigation of various stoichiometries of the well-studied poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester (P3HT:PCBM) active layer mixture. Images of the surface were obtained using AC-mode AFM exciting higher-order resonance frequencies of a standard silicon probe, a promising technique for acquiring real-space images of organic-based thin films with nanoscale and even submolecular resolution. We provide firm evidence of the nanoscale organization of the P3HT polymer and of the P3HT:PCBM stoichiometric mixtures at the surface-air interface of the BHJ architecture. Our study shows the characteristic periodicity of the regioregular P3HT identified in the nanoscale domain areas with submolecular resolution. Such areas are then distorted in place when adding different quantities of PCBM forming stoichiometric mixtures. When the samples were exposed to ambient light, the morphologies were very different, and submolecular resolution was not achieved. This approach is shown to provide a precise view of the active layer's nanostructure and will be useful for studies of other materials as a function of various parameters, with particular attention to the role of the acceptor in tuning morphology for understanding optimum performance in organic photovoltaic devices.
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Affiliation(s)
- Letizia Liirò-Peluso
- The
GSK Carbon Neutral Laboratories for Sustainable Chemistry, School
of Chemistry, University of Nottingham, Triumph Road, Nottingham NG7 2TU, U.K.
- School
of Physics and Astronomy, University of
Nottingham, University
Park, Nottingham NG7 2RD, U.K.
| | - James Wrigley
- School
of Physics and Astronomy, University of
Nottingham, University
Park, Nottingham NG7 2RD, U.K.
| | - David B. Amabilino
- The
GSK Carbon Neutral Laboratories for Sustainable Chemistry, School
of Chemistry, University of Nottingham, Triumph Road, Nottingham NG7 2TU, U.K.
- Institut
de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones
Científicas, Carrer dels Til.lers, Campus Universitari de Bellaterra, 08193 Cerdanyola del Vallès, Spain
| | - Peter H. Beton
- School
of Physics and Astronomy, University of
Nottingham, University
Park, Nottingham NG7 2RD, U.K.
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5
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Mendelson N, Chugh D, Reimers JR, Cheng TS, Gottscholl A, Long H, Mellor CJ, Zettl A, Dyakonov V, Beton PH, Novikov SV, Jagadish C, Tan HH, Ford MJ, Toth M, Bradac C, Aharonovich I. Identifying carbon as the source of visible single-photon emission from hexagonal boron nitride. Nat Mater 2021; 20:321-328. [PMID: 33139892 DOI: 10.1038/s41563-020-00850-y] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 09/30/2020] [Indexed: 05/05/2023]
Abstract
Single-photon emitters (SPEs) in hexagonal boron nitride (hBN) have garnered increasing attention over the last few years due to their superior optical properties. However, despite the vast range of experimental results and theoretical calculations, the defect structure responsible for the observed emission has remained elusive. Here, by controlling the incorporation of impurities into hBN via various bottom-up synthesis methods and directly through ion implantation, we provide direct evidence that the visible SPEs are carbon related. Room-temperature optically detected magnetic resonance is demonstrated on ensembles of these defects. We perform ion-implantation experiments and confirm that only carbon implantation creates SPEs in the visible spectral range. Computational analysis of the simplest 12 carbon-containing defect species suggest the negatively charged [Formula: see text] defect as a viable candidate and predict that out-of-plane deformations make the defect environmentally sensitive. Our results resolve a long-standing debate about the origin of single emitters at the visible range in hBN and will be key to the deterministic engineering of these defects for quantum photonic devices.
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Affiliation(s)
- Noah Mendelson
- School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Dipankar Chugh
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Jeffrey R Reimers
- School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
- International Centre for Quantum and Molecular Structures and Department of Physics, Shanghai University, Shanghai, China
| | - Tin S Cheng
- School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Andreas Gottscholl
- Experimental Physics 6 and Würzburg-Dresden Cluster of Excellence, Julius Maximilian University of Würzburg, Würzburg, Germany
| | - Hu Long
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Kavli Energy NanoSciences Institute at the University of California and the Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Alex Zettl
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Kavli Energy NanoSciences Institute at the University of California and the Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vladimir Dyakonov
- Experimental Physics 6 and Würzburg-Dresden Cluster of Excellence, Julius Maximilian University of Würzburg, Würzburg, Germany
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Sergei V Novikov
- School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Chennupati Jagadish
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory, Australia
- ARC Centre of Excellence for Transformative Meta-Optical Systems, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Hark Hoe Tan
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory, Australia
- ARC Centre of Excellence for Transformative Meta-Optical Systems, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Michael J Ford
- School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Milos Toth
- School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
- ARC Centre of Excellence for Transformative Meta-Optical Systems, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Carlo Bradac
- School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
- Department of Physics & Astronomy, Trent University, Peterborough, Ontario, Canada
| | - Igor Aharonovich
- School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia.
- ARC Centre of Excellence for Transformative Meta-Optical Systems, University of Technology Sydney, Sydney, New South Wales, Australia.
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6
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Wade J, Hilfiker JN, Brandt JR, Liirò-Peluso L, Wan L, Shi X, Salerno F, Ryan STJ, Schöche S, Arteaga O, Jávorfi T, Siligardi G, Wang C, Amabilino DB, Beton PH, Campbell AJ, Fuchter MJ. Natural optical activity as the origin of the large chiroptical properties in π-conjugated polymer thin films. Nat Commun 2020; 11:6137. [PMID: 33262352 PMCID: PMC7708482 DOI: 10.1038/s41467-020-19951-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [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: 06/02/2020] [Accepted: 11/06/2020] [Indexed: 11/09/2022] Open
Abstract
Polymer thin films that emit and absorb circularly polarised light have been demonstrated with the promise of achieving important technological advances; from efficient, high-performance displays, to 3D imaging and all-organic spintronic devices. However, the origin of the large chiroptical effects in such films has, until now, remained elusive. We investigate the emergence of such phenomena in achiral polymers blended with a chiral small-molecule additive (1-aza[6]helicene) and intrinsically chiral-sidechain polymers using a combination of spectroscopic methods and structural probes. We show that – under conditions relevant for device fabrication – the large chiroptical effects are caused by magneto-electric coupling (natural optical activity), not structural chirality as previously assumed, and may occur because of local order in a cylinder blue phase-type organisation. This disruptive mechanistic insight into chiral polymer thin films will offer new approaches towards chiroptical materials development after almost three decades of research in this area. Polymer thin films that emit and absorb circularly polarised light are promising in achieving important technological advances, but the origin of the large chiroptical effects in such films has remained elusive. Here the authors demonstrate that in non-aligned polymer thin films, large chiroptical effects are caused by magneto-electric coupling, not structural chirality as previously assumed.
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Affiliation(s)
- Jessica Wade
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.,Centre for Processable Electronics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - James N Hilfiker
- J.A. Woollam Co. Inc., 645M Street, Suite 102, Lincoln, NE, 68508-2243, USA
| | - Jochen R Brandt
- Centre for Processable Electronics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.,Department of Chemistry and Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Letizia Liirò-Peluso
- School of Chemistry & The GSK Carbon Neutral Laboratories for Sustainable Chemistry, University of Nottingham, Triumph Road, Nottingham, NG7 2TU, UK.,School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Li Wan
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.,Centre for Processable Electronics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Xingyuan Shi
- Centre for Processable Electronics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.,Department of Chemistry and Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Francesco Salerno
- Centre for Processable Electronics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.,Department of Chemistry and Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Seán T J Ryan
- Department of Chemistry and Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Stefan Schöche
- J.A. Woollam Co. Inc., 645M Street, Suite 102, Lincoln, NE, 68508-2243, USA
| | - Oriol Arteaga
- Departament de Física Aplicada, Universitat de Barcelona, IN2UB, Barcelona, 08028, Spain
| | - Tamás Jávorfi
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Giuliano Siligardi
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Cheng Wang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA
| | - David B Amabilino
- School of Chemistry & The GSK Carbon Neutral Laboratories for Sustainable Chemistry, University of Nottingham, Triumph Road, Nottingham, NG7 2TU, UK
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Alasdair J Campbell
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK. .,Centre for Processable Electronics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
| | - Matthew J Fuchter
- Centre for Processable Electronics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK. .,Department of Chemistry and Molecular Sciences Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK.
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7
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Kerfoot J, Svatek SA, Korolkov VV, Taniguchi T, Watanabe K, Antolin E, Beton PH. Fluorescence and Electroluminescence of J-Aggregated Polythiophene Monolayers on Hexagonal Boron Nitride. ACS Nano 2020; 14:13886-13893. [PMID: 32897689 DOI: 10.1021/acsnano.0c06280] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The photophysics of a semiconducting polymer is manipulated through molecular self-assembly on an insulating surface. Adsorption of polythiophene (PT) monolayers on hexagonal boron nitride (hBN) leads to a structurally induced planarization and a rebalancing of inter- and intrachain excitonic coupling. This conformational control results in a dominant 0-0 photoluminescence peak and a reduced Huang-Rhys factor, characteristic of J-type aggregates, and optical properties which are significantly different to both PT thin films and single polymer strands. Adsorption on hBN also provides a route to explore electroluminescence from PT monolayers though incorporation into hybrid van der Waals heterostructures whereby the polymer monolayer is embedded within a hBN tunnel diode. In these structures we observe up-converted singlet electroluminescence from the PT monolayer, with an excitation mechanism based upon inelastic electron scattering. We argue that surface adsorption provides a methodology for the study of fundamental optoelectronic properties of technologically relevant polymers.
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Affiliation(s)
- James Kerfoot
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Simon A Svatek
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
- Instituto de Energía Solar, Universidad Politécnica de Madrid, Avenida Complutense 30, Madrid 28040, Spain
| | - Vladimir V Korolkov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Elisa Antolin
- Instituto de Energía Solar, Universidad Politécnica de Madrid, Avenida Complutense 30, Madrid 28040, Spain
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
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8
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Weston A, Zou Y, Enaldiev V, Summerfield A, Clark N, Zólyomi V, Graham A, Yelgel C, Magorrian S, Zhou M, Zultak J, Hopkinson D, Barinov A, Bointon TH, Kretinin A, Wilson NR, Beton PH, Fal'ko VI, Haigh SJ, Gorbachev R. Atomic reconstruction in twisted bilayers of transition metal dichalcogenides. Nat Nanotechnol 2020; 15:592-597. [PMID: 32451502 DOI: 10.1038/s41565-020-0682-9] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 03/23/2020] [Indexed: 05/22/2023]
Abstract
Van der Waals heterostructures form a unique class of layered artificial solids in which physical properties can be manipulated through controlled composition, order and relative rotation of adjacent atomic planes. Here we use atomic-resolution transmission electron microscopy to reveal the lattice reconstruction in twisted bilayers of the transition metal dichalcogenides, MoS2 and WS2. For twisted 3R bilayers, a tessellated pattern of mirror-reflected triangular 3R domains emerges, separated by a network of partial dislocations for twist angles θ < 2°. The electronic properties of these 3R domains, featuring layer-polarized conduction-band states caused by lack of both inversion and mirror symmetry, appear to be qualitatively different from those of 2H transition metal dichalcogenides. For twisted 2H bilayers, stable 2H domains dominate, with nuclei of a second metastable phase. This appears as a kagome-like pattern at θ ≈ 2°, transitioning at θ → 0 to a hexagonal array of screw dislocations separating large-area 2H domains. Tunnelling measurements show that such reconstruction creates strong piezoelectric textures, opening a new avenue for engineering of 2D material properties.
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Affiliation(s)
- Astrid Weston
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Yichao Zou
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Materials, University of Manchester, Manchester, UK
| | - Vladimir Enaldiev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
- Kotel'nikov Institute of Radio-engineering and Electronics, Russian Academy of Sciences, Moscow, Russia
| | - Alex Summerfield
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Nicholas Clark
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Materials, University of Manchester, Manchester, UK
| | - Viktor Zólyomi
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Abigail Graham
- Department of Physics, University of Warwick, Coventry, UK
| | - Celal Yelgel
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Samuel Magorrian
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Mingwei Zhou
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Johanna Zultak
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - David Hopkinson
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Materials, University of Manchester, Manchester, UK
| | | | - Thomas H Bointon
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Andrey Kretinin
- National Graphene Institute, University of Manchester, Manchester, UK
- Department of Materials, University of Manchester, Manchester, UK
| | - Neil R Wilson
- Department of Physics, University of Warwick, Coventry, UK
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Vladimir I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK.
| | - Sarah J Haigh
- National Graphene Institute, University of Manchester, Manchester, UK.
- Department of Materials, University of Manchester, Manchester, UK.
| | - Roman Gorbachev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK.
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9
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Svatek SA, Kerfoot J, Summerfield A, Nizovtsev AS, Korolkov VV, Taniguchi T, Watanabe K, Antolín E, Besley E, Beton PH. Triplet Excitation and Electroluminescence from a Supramolecular Monolayer Embedded in a Boron Nitride Tunnel Barrier. Nano Lett 2020; 20:278-283. [PMID: 31821763 DOI: 10.1021/acs.nanolett.9b03787] [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: 06/10/2023]
Abstract
We show that ordered monolayers of organic molecules stabilized by hydrogen bonding on the surface of exfoliated few-layer hexagonal boron nitride (hBN) flakes may be incorporated into van der Waals heterostructures with integral few-layer graphene contacts forming a molecular/two-dimensional hybrid tunneling diode. Electrons can tunnel through the hBN/molecular barrier under an applied voltage VSD, and we observe molecular electroluminescence from an excited singlet state with an emitted photon energy hν > eVSD, indicating upconversion by energies up to ∼1 eV. We show that tunneling electrons excite embedded molecules into singlet states in a two-step process via an intermediate triplet state through inelastic scattering and also observe direct emission from the triplet state. These heterostructures provide a solid-state device in which spin-triplet states, which cannot be generated by optical transitions, can be controllably excited and provide a new route to investigate the physics, chemistry, and quantum spin-based applications of triplet generation, emission, and molecular photon upconversion.
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Affiliation(s)
| | | | | | - Anton S Nizovtsev
- Nikolaev Institute of Inorganic Chemistry , Siberian Branch of the Russian Academy of Sciences , Academician Lavrentiev Avenue 3 , Novosibirsk 630090 , Russian Federation
| | | | - Takashi Taniguchi
- National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Ibaraki , Japan
| | - Kenji Watanabe
- National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Ibaraki , Japan
| | - Elisa Antolín
- Instituto de Energía Solar , Universidad Politécnica de Madrid , Avenida Complutense 30 , Madrid 28040 , Spain
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10
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Bolognesi M, Brucale M, Lorenzoni A, Prescimone F, Moschetto S, Korolkov VV, Baldoni M, Serrano-Ruiz M, Caporali M, Mercuri F, Besley E, Muccini M, Peruzzini M, Beton PH, Toffanin S. Epitaxial multilayers of alkanes on two-dimensional black phosphorus as passivating and electrically insulating nanostructures. Nanoscale 2019; 11:17252-17261. [PMID: 31317153 DOI: 10.1039/c9nr01155b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mechanically exfoliated two-dimensional (2D) black phosphorus (bP) is epitaxially terminated by monolayers and multilayers of tetracosane, a linear alkane, to form a weakly interacting van der Waals heterostructure. Atomic force microscopy (AFM) and computational modelling show that epitaxial domains of alkane chains are ordered in parallel lamellae along the principal crystalline axis of bP, and this order is extended over a few layers above the interface. Epitaxial alkane multilayers delay the oxidation of 2D bP in air by 18 hours, in comparison to 1 hour for bare 2D bP, and act as an electrical insulator, as demonstrated using electrostatic force microscopy. The presented heterostructure is a technologically relevant insulator-semiconductor model system that can open the way to the use of 2D bP in micro- and nanoelectronic, optoelectronic and photonic applications.
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Affiliation(s)
- Margherita Bolognesi
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Marco Brucale
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Andrea Lorenzoni
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Federico Prescimone
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Salvatore Moschetto
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Vladimir V Korolkov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Matteo Baldoni
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Manuel Serrano-Ruiz
- Istituto di Chimica dei Composti Organometallici (ICCOM) - Consiglio Nazionale delle Ricerche (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Maria Caporali
- Istituto di Chimica dei Composti Organometallici (ICCOM) - Consiglio Nazionale delle Ricerche (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Francesco Mercuri
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Elena Besley
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK
| | - Michele Muccini
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Maurizio Peruzzini
- Istituto di Chimica dei Composti Organometallici (ICCOM) - Consiglio Nazionale delle Ricerche (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Stefano Toffanin
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) - Consiglio Nazionale delle Ricerche (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
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11
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Abstract
Dispersion interactions are commonly included in density functional theory (DFT) calculations through the addition of an empirical correction. In this study, a modification is made to the damping function in DFT-D2 calculations to describe repulsion at small internuclear distances. The resulting Atomic Interactions Represented By Empirical Dispersion (AIRBED) approach is used to model the physisorption of molecules on surfaces such as graphene and hexagonal boron nitride, where the constituent atoms of the surface are no longer required to be included explicitly in the density functional theory calculation but are represented by a point charge to capture electrostatic effects. It is shown that this model can reproduce the structures predicted by full DFT-D2 calculations to a high degree of accuracy. The significant reduction in computational cost allows much larger systems to be studied, including molecular arrays on surfaces and sandwich complexes involving organic molecules between two surface layers.
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Affiliation(s)
- Stephen E Mason
- School of Physics & Astronomy , University of Nottingham , University Park , Nottingham NG7 2RD , United Kingdom
| | - Peter H Beton
- School of Chemistry , University of Nottingham , University Park , Nottingham NG7 2RD , United Kindom
| | - Nicholas A Besley
- School of Physics & Astronomy , University of Nottingham , University Park , Nottingham NG7 2RD , United Kingdom
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12
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Elias C, Valvin P, Pelini T, Summerfield A, Mellor CJ, Cheng TS, Eaves L, Foxon CT, Beton PH, Novikov SV, Gil B, Cassabois G. Direct band-gap crossover in epitaxial monolayer boron nitride. Nat Commun 2019; 10:2639. [PMID: 31201328 PMCID: PMC6572751 DOI: 10.1038/s41467-019-10610-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [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: 02/25/2019] [Accepted: 05/22/2019] [Indexed: 12/01/2022] Open
Abstract
Hexagonal boron nitride is a large band-gap insulating material which complements the electronic and optical properties of graphene and the transition metal dichalcogenides. However, the intrinsic optical properties of monolayer boron nitride remain largely unexplored. In particular, the theoretically expected crossover to a direct-gap in the limit of the single monolayer is presently not confirmed experimentally. Here, in contrast to the technique of exfoliating few-layer 2D hexagonal boron nitride, we exploit the scalable approach of high-temperature molecular beam epitaxy to grow high-quality monolayer boron nitride on graphite substrates. We combine deep-ultraviolet photoluminescence and reflectance spectroscopy with atomic force microscopy to reveal the presence of a direct gap of energy 6.1 eV in the single atomic layers, thus confirming a crossover to direct gap in the monolayer limit.
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Affiliation(s)
- C Elias
- Laboratoire Charles Coulomb, UMR5221 CNRS-Université de Montpellier, 34095, Montpellier, France
| | - P Valvin
- Laboratoire Charles Coulomb, UMR5221 CNRS-Université de Montpellier, 34095, Montpellier, France
| | - T Pelini
- Laboratoire Charles Coulomb, UMR5221 CNRS-Université de Montpellier, 34095, Montpellier, France
| | - A Summerfield
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - C J Mellor
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - T S Cheng
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - L Eaves
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - C T Foxon
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - P H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - S V Novikov
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - B Gil
- Laboratoire Charles Coulomb, UMR5221 CNRS-Université de Montpellier, 34095, Montpellier, France
| | - G Cassabois
- Laboratoire Charles Coulomb, UMR5221 CNRS-Université de Montpellier, 34095, Montpellier, France.
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13
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Korolkov VV, Summerfield A, Murphy A, Amabilino DB, Watanabe K, Taniguchi T, Beton PH. Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy. Nat Commun 2019; 10:1537. [PMID: 30948725 PMCID: PMC6449331 DOI: 10.1038/s41467-019-09571-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [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: 12/17/2018] [Accepted: 03/19/2019] [Indexed: 11/09/2022] Open
Abstract
Real-space images of polymers with sub-molecular resolution could provide valuable insights into the relationship between morphology and functionality of polymer optoelectronic devices, but their acquisition is problematic due to perceived limitations in atomic force microscopy (AFM). We show that individual thiophene units and the lattice of semicrystalline spin-coated films of polythiophenes (PTs) may be resolved using AFM under ambient conditions through the low-amplitude (≤ 1 nm) excitation of higher eigenmodes of a cantilever. PT strands are adsorbed on hexagonal boron nitride near-parallel to the surface in islands with lateral dimensions ~10 nm. On the surface of a spin-coated PT thin film, in which the thiophene groups are perpendicular to the interface, we resolve terminal CH3-groups in a square arrangement with a lattice constant 0.55 nm from which we can identify abrupt boundaries and also regions with more slowly varying disorder, which allow comparison with proposed models of PT domains.
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Affiliation(s)
- Vladimir V Korolkov
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
| | - Alex Summerfield
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Alanna Murphy
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - David B Amabilino
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
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14
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Goronzy DP, Ebrahimi M, Rosei F, Fang Y, De Feyter S, Tait SL, Wang C, Beton PH, Wee ATS, Weiss PS, Perepichka DF. Supramolecular Assemblies on Surfaces: Nanopatterning, Functionality, and Reactivity. ACS Nano 2018; 12:7445-7481. [PMID: 30010321 DOI: 10.1021/acsnano.8b03513] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Understanding how molecules interact to form large-scale hierarchical structures on surfaces holds promise for building designer nanoscale constructs with defined chemical and physical properties. Here, we describe early advances in this field and highlight upcoming opportunities and challenges. Both direct intermolecular interactions and those that are mediated by coordinated metal centers or substrates are discussed. These interactions can be additive, but they can also interfere with each other, leading to new assemblies in which electrical potentials vary at distances much larger than those of typical chemical interactions. Earlier spectroscopic and surface measurements have provided partial information on such interfacial effects. In the interim, scanning probe microscopies have assumed defining roles in the field of molecular organization on surfaces, delivering deeper understanding of interactions, structures, and local potentials. Self-assembly is a key strategy to form extended structures on surfaces, advancing nanolithography into the chemical dimension and providing simultaneous control at multiple scales. In parallel, the emergence of graphene and the resulting impetus to explore 2D materials have broadened the field, as surface-confined reactions of molecular building blocks provide access to such materials as 2D polymers and graphene nanoribbons. In this Review, we describe recent advances and point out promising directions that will lead to even greater and more robust capabilities to exploit designer surfaces.
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Affiliation(s)
- Dominic P Goronzy
- California NanoSystems Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
- Department of Chemistry and Biochemistry , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Maryam Ebrahimi
- INRS Centre for Energy, Materials and Telecommunications , 1650 Boul. Lionel Boulet , Varennes , Quebec J3X 1S2 , Canada
| | - Federico Rosei
- INRS Centre for Energy, Materials and Telecommunications , 1650 Boul. Lionel Boulet , Varennes , Quebec J3X 1S2 , Canada
- Institute for Fundamental and Frontier Science , University of Electronic Science and Technology of China , Chengdu 610054 , P.R. China
| | - Yuan Fang
- Department of Chemistry , McGill University , Montreal H3A 0B8 , Canada
| | - Steven De Feyter
- Department of Chemistry , KU Leuven , Celestijnenlaan 200F , Leuven 3001 , Belgium
| | - Steven L Tait
- Department of Chemistry , Indiana University , Bloomington , Indiana 47405 , United States
| | - Chen Wang
- National Center for Nanoscience and Technology , Beijing 100190 , China
| | - Peter H Beton
- School of Physics & Astronomy , University of Nottingham , Nottingham NG7 2RD , United Kingdom
| | - Andrew T S Wee
- Department of Physics , National University of Singapore , 117542 Singapore
| | - Paul S Weiss
- California NanoSystems Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
- Department of Chemistry and Biochemistry , University of California, Los Angeles , Los Angeles , California 90095 , United States
- Department of Materials Science and Engineering , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Dmitrii F Perepichka
- California NanoSystems Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
- Department of Chemistry , McGill University , Montreal H3A 0B8 , Canada
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15
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Kerfoot J, Korolkov VV, Nizovtsev AS, Jones R, Taniguchi T, Watanabe K, Lesanovsky I, Olmos B, Besley NA, Besley E, Beton PH. Substrate-induced shifts and screening in the fluorescence spectra of supramolecular adsorbed organic monolayers. J Chem Phys 2018; 149:054701. [DOI: 10.1063/1.5041418] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- James Kerfoot
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Vladimir V. Korolkov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Anton S. Nizovtsev
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Academician Lavrentiev Avenue 3, 630090 Novosibirsk, Russian Federation
| | - Ryan Jones
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Igor Lesanovsky
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Beatriz Olmos
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Nicholas A. Besley
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Elena Besley
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Peter H. Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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16
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Summerfield A, Kozikov A, Cheng TS, Davies A, Cho YJ, Khlobystov AN, Mellor CJ, Foxon CT, Watanabe K, Taniguchi T, Eaves L, Novoselov KS, Novikov SV, Beton PH. Moiré-Modulated Conductance of Hexagonal Boron Nitride Tunnel Barriers. Nano Lett 2018; 18:4241-4246. [PMID: 29913062 PMCID: PMC6095635 DOI: 10.1021/acs.nanolett.8b01223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/13/2018] [Indexed: 05/27/2023]
Abstract
Monolayer hexagonal boron nitride (hBN) tunnel barriers investigated using conductive atomic force microscopy reveal moiré patterns in the spatial maps of their tunnel conductance consistent with the formation of a moiré superlattice between the hBN and an underlying highly ordered pyrolytic graphite (HOPG) substrate. This variation is attributed to a periodc modulation of the local density of states and occurs for both exfoliated hBN barriers and epitaxially grown layers. The epitaxial barriers also exhibit enhanced conductance at localized subnanometer regions which are attributed to exposure of the substrate to a nitrogen plasma source during the high temperature growth process. Our results show clearly a spatial periodicity of tunnel current due to the formation of a moiré superlattice and we argue that this can provide a mechanism for elastic scattering of charge carriers for similar interfaces embedded in graphene/hBN resonant tunnel diodes.
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Affiliation(s)
- Alex Summerfield
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Aleksey Kozikov
- School of Physics and
Astronomy and National Graphene Institute, University
of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Tin S. Cheng
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Andrew Davies
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
- School of Chemistry and Nottingham Nanoscale and Microscale Research Centre, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Yong-Jin Cho
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Andrei N. Khlobystov
- School of Chemistry and Nottingham Nanoscale and Microscale Research Centre, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Christopher J. Mellor
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - C. Thomas Foxon
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibraki 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibraki 305-0044, Japan
| | - Laurence Eaves
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Kostya S. Novoselov
- School of Physics and
Astronomy and National Graphene Institute, University
of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Sergei V. Novikov
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Peter H. Beton
- School of Physics
and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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17
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Cheng TS, Summerfield A, Mellor CJ, Khlobystov AN, Eaves L, Foxon CT, Beton PH, Novikov SV. High-Temperature Molecular Beam Epitaxy of Hexagonal Boron Nitride with High Active Nitrogen Fluxes. Materials (Basel) 2018; 11:E1119. [PMID: 29966333 PMCID: PMC6073546 DOI: 10.3390/ma11071119] [Citation(s) in RCA: 14] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 06/25/2018] [Accepted: 06/26/2018] [Indexed: 11/28/2022]
Abstract
Hexagonal boron nitride (hBN) has attracted a great deal of attention as a key component in van der Waals (vdW) heterostructures, and as a wide band gap material for deep-ultraviolet devices. We have recently demonstrated plasma-assisted molecular beam epitaxy (PA-MBE) of hBN layers on substrates of highly oriented pyrolytic graphite at high substrate temperatures of ~1400 °C. The current paper will present data on the high-temperature PA-MBE growth of hBN layers using a high-efficiency radio-frequency (RF) nitrogen plasma source. Despite more than a three-fold increase in nitrogen flux with this new source, we saw no significant increase in the growth rates of the hBN layers, indicating that the growth rate of hBN layers is controlled by the boron arrival rate. The hBN thickness increases to 90 nm with decrease in the growth temperature to 1080 °C. However, the decrease in the MBE temperature led to a deterioration in the optical properties of the hBN. The optical absorption data indicates that an increase in the active nitrogen flux during the PA-MBE process improves the optical properties of hBN and suppresses defect related optical absorption in the energy range 5.0⁻5.5 eV.
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Affiliation(s)
- Tin S Cheng
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Alex Summerfield
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Christopher J Mellor
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | | | - Laurence Eaves
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | - C Thomas Foxon
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Sergei V Novikov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
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18
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Davies A, Albar JD, Summerfield A, Thomas JC, Cheng TS, Korolkov VV, Stapleton E, Wrigley J, Goodey NL, Mellor CJ, Khlobystov AN, Watanabe K, Taniguchi T, Foxon CT, Eaves L, Novikov SV, Beton PH. Lattice-Matched Epitaxial Graphene Grown on Boron Nitride. Nano Lett 2018; 18:498-504. [PMID: 29211487 DOI: 10.1021/acs.nanolett.7b04453] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Lattice-matched graphene on hexagonal boron nitride is expected to lead to the formation of a band gap but requires the formation of highly strained material and has not hitherto been realized. We demonstrate that aligned, lattice-matched graphene can be grown by molecular beam epitaxy using substrate temperatures in the range 1600-1710 °C and coexists with a topologically modified moiré pattern with regions of strained graphene which have giant moiré periods up to ∼80 nm. Raman spectra reveal narrow red-shifted peaks due to isotropic strain, while the giant moiré patterns result in complex splitting of Raman peaks due to strain variations across the moiré unit cell. The lattice-matched graphene has a lower conductance than both the Frenkel-Kontorova-type domain walls and also the topological defects where they terminate. We relate these results to theoretical models of band gap formation in graphene/boron nitride heterostructures.
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Affiliation(s)
- Andrew Davies
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
- School of Chemistry, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Juan D Albar
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Alex Summerfield
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - James C Thomas
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Tin S Cheng
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Vladimir V Korolkov
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Emily Stapleton
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - James Wrigley
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Nathan L Goodey
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Christopher J Mellor
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Andrei N Khlobystov
- School of Chemistry, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Kenji Watanabe
- National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - C Thomas Foxon
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Laurence Eaves
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Sergei V Novikov
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham , Nottingham NG7 2RD, United Kingdom
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19
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Alkhamisi M, Korolkov VV, Nizovtsev AS, Kerfoot J, Taniguchi T, Watanabe K, Besley NA, Besley E, Beton PH. The growth and fluorescence of phthalocyanine monolayers, thin films and multilayers on hexagonal boron nitride. Chem Commun (Camb) 2018; 54:12021-12024. [DOI: 10.1039/c8cc06304d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Free-base phthalocyanine forms distinct interfacial phases and thin films on hexagonal boron nitride including a monolayer arrangement as determined using high resolution atomic force microscopy.
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Affiliation(s)
- Manal Alkhamisi
- School of Physics & Astronomy
- University of Nottingham
- Nottingham NG7 2RD
- UK
| | | | - Anton S. Nizovtsev
- School of Chemistry
- University of Nottingham
- Nottingham NG7 2RD
- UK
- Nikolaev Institute of Inorganic Chemistry
| | - James Kerfoot
- School of Physics & Astronomy
- University of Nottingham
- Nottingham NG7 2RD
- UK
| | | | - Kenji Watanabe
- National Institute for Materials Science
- Ibaraki 305-0044
- Japan
| | | | - Elena Besley
- School of Chemistry
- University of Nottingham
- Nottingham NG7 2RD
- UK
| | - Peter H. Beton
- School of Physics & Astronomy
- University of Nottingham
- Nottingham NG7 2RD
- UK
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20
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Kudrynskyi ZR, Bhuiyan MA, Makarovsky O, Greener JDG, Vdovin EE, Kovalyuk ZD, Cao Y, Mishchenko A, Novoselov KS, Beton PH, Eaves L, Patanè A. Giant Quantum Hall Plateau in Graphene Coupled to an InSe van der Waals Crystal. Phys Rev Lett 2017; 119:157701. [PMID: 29077458 DOI: 10.1103/physrevlett.119.157701] [Citation(s) in RCA: 4] [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: 06/06/2017] [Indexed: 05/07/2023]
Abstract
We report on a "giant" quantum Hall effect plateau in a graphene-based field-effect transistor where graphene is capped by a layer of the van der Waals crystal InSe. The giant quantum Hall effect plateau arises from the close alignment of the conduction band edge of InSe with the Dirac point of graphene. This feature enables the magnetic-field- and electric-field-effect-induced transfer of charge carriers between InSe and the degenerate Landau level states of the adjacent graphene layer, which is coupled by a van der Waals heterointerface to the InSe.
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Affiliation(s)
- Z R Kudrynskyi
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - M A Bhuiyan
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - O Makarovsky
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - J D G Greener
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - E E Vdovin
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Institute of Microelectronics Technology and High Purity Materials, RAS, Chernogolovka 142432, Russia
| | - Z D Kovalyuk
- Institute for Problems of Materials Science, The National Academy of Sciences of Ukraine, Chernivtsi Branch, Chernivtsi 58001, Ukraine
| | - Y Cao
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Manchester M13 9PL, United Kingdom
| | - A Mishchenko
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - K S Novoselov
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - P H Beton
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - L Eaves
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - A Patanè
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
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21
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Albar JD, Summerfield A, Cheng TS, Davies A, Smith EF, Khlobystov AN, Mellor CJ, Taniguchi T, Watanabe K, Foxon CT, Eaves L, Beton PH, Novikov SV. An atomic carbon source for high temperature molecular beam epitaxy of graphene. Sci Rep 2017; 7:6598. [PMID: 28747805 PMCID: PMC5529545 DOI: 10.1038/s41598-017-07021-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 04/07/2017] [Accepted: 06/20/2017] [Indexed: 12/04/2022] Open
Abstract
We report the use of a novel atomic carbon source for the molecular beam epitaxy (MBE) of graphene layers on hBN flakes and on sapphire wafers at substrate growth temperatures of ~1400 °C. The source produces a flux of predominantly atomic carbon, which diffuses through the walls of a Joule-heated tantalum tube filled with graphite powder. We demonstrate deposition of carbon on sapphire with carbon deposition rates up to 12 nm/h. Atomic force microscopy measurements reveal the formation of hexagonal moiré patterns when graphene monolayers are grown on hBN flakes. The Raman spectra of the graphene layers grown on hBN and sapphire with the sublimation carbon source and the atomic carbon source are similar, whilst the nature of the carbon aggregates is different - graphitic with the sublimation carbon source and amorphous with the atomic carbon source. At MBE growth temperatures we observe etching of the sapphire wafer surface by the flux from the atomic carbon source, which we have not observed in the MBE growth of graphene with the sublimation carbon source.
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Affiliation(s)
- J D Albar
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - A Summerfield
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - T S Cheng
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - A Davies
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.,Nanoscale and microscale research centre (NMRC) and School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - E F Smith
- Nanoscale and microscale research centre (NMRC) and School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - A N Khlobystov
- Nanoscale and microscale research centre (NMRC) and School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - C J Mellor
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - T Taniguchi
- The National Institute for Materials Science, Advanced Materials Laboratory, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - K Watanabe
- The National Institute for Materials Science, Advanced Materials Laboratory, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - C T Foxon
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - L Eaves
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - P H Beton
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - S V Novikov
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
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22
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Korolkov VV, Baldoni M, Watanabe K, Taniguchi T, Besley E, Beton PH. Supramolecular heterostructures formed by sequential epitaxial deposition of two-dimensional hydrogen-bonded arrays. Nat Chem 2017; 9:1191-1197. [PMID: 29168478 DOI: 10.1038/nchem.2824] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/06/2017] [Indexed: 01/27/2023]
Abstract
Two-dimensional (2D) supramolecular arrays provide a route to the spatial control of the chemical functionality of a surface, but their deposition is in almost all cases limited to a monolayer termination. Here we investigated the sequential deposition of one 2D array on another to form a supramolecular heterostructure and realize the growth-normal to the underlying substrate-of distinct ordered layers, each of which is stabilized by in-plane hydrogen bonding. For heterostructures formed by depositing terephthalic acid or trimesic acid on cyanuric acid/melamine, we have determined, using atomic force microscopy under ambient conditions, a clear epitaxial arrangement despite the intrinsically distinct symmetries and/or lattice constants of each layer. Structures calculated using classical molecular dynamics are in excellent agreement with the orientation, registry and dimensions of the epitaxial layers. Calculations confirm that van der Waals interactions provide the dominant contribution to the adsorption energy and registry of the layers.
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Affiliation(s)
- Vladimir V Korolkov
- School of Physics & Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Matteo Baldoni
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Elena Besley
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK
| | - Peter H Beton
- School of Physics & Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
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23
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Summerfield A, Davies A, Cheng TS, Korolkov VV, Cho Y, Mellor CJ, Foxon CT, Khlobystov AN, Watanabe K, Taniguchi T, Eaves L, Novikov SV, Beton PH. Strain-Engineered Graphene Grown on Hexagonal Boron Nitride by Molecular Beam Epitaxy. Sci Rep 2016; 6:22440. [PMID: 26928710 PMCID: PMC4772548 DOI: 10.1038/srep22440] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [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: 12/09/2015] [Accepted: 02/15/2016] [Indexed: 11/24/2022] Open
Abstract
Graphene grown by high temperature molecular beam epitaxy on hexagonal boron nitride (hBN) forms continuous domains with dimensions of order 20 μm, and exhibits moiré patterns with large periodicities, up to ~30 nm, indicating that the layers are highly strained. Topological defects in the moiré patterns are observed and attributed to the relaxation of graphene islands which nucleate at different sites and subsequently coalesce. In addition, cracks are formed leading to strain relaxation, highly anisotropic strain fields, and abrupt boundaries between regions with different moiré periods. These cracks can also be formed by modification of the layers with a local probe resulting in the contraction and physical displacement of graphene layers. The Raman spectra of regions with a large moiré period reveal split and shifted G and 2D peaks confirming the presence of strain. Our work demonstrates a new approach to the growth of epitaxial graphene and a means of generating and modifying strain in graphene.
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Affiliation(s)
- Alex Summerfield
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Andrew Davies
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Tin S. Cheng
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Vladimir V. Korolkov
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - YongJin Cho
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | | | - C. Thomas Foxon
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | | | - Kenji Watanabe
- The National Institute for Materials Science, Advanced Materials Laboratory, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- The National Institute for Materials Science, Advanced Materials Laboratory, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Laurence Eaves
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Sergei V. Novikov
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter H. Beton
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
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24
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Krap CP, Newby R, Dhakshinamoorthy A, García H, Cebula I, Easun TL, Savage M, Eyley JE, Gao S, Blake AJ, Lewis W, Beton PH, Warren MR, Allan DR, Frogley MD, Tang CC, Cinque G, Yang S, Schröder M. Enhancement of CO2 Adsorption and Catalytic Properties by Fe-Doping of [Ga2(OH)2(L)] (H4L = Biphenyl-3,3',5,5'-tetracarboxylic Acid), MFM-300(Ga2). Inorg Chem 2016; 55:1076-88. [PMID: 26757137 PMCID: PMC4805307 DOI: 10.1021/acs.inorgchem.5b02108] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [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] [Indexed: 11/29/2022]
Abstract
Metal-organic frameworks (MOFs) are usually synthesized using a single type of metal ion, and MOFs containing mixtures of different metal ions are of great interest and represent a methodology to enhance and tune materials properties. We report the synthesis of [Ga2(OH)2(L)] (H4L = biphenyl-3,3',5,5'-tetracarboxylic acid), designated as MFM-300(Ga2), (MFM = Manchester Framework Material replacing NOTT designation), by solvothermal reaction of Ga(NO3)3 and H4L in a mixture of DMF, THF, and water containing HCl for 3 days. MFM-300(Ga2) crystallizes in the tetragonal space group I4122, a = b = 15.0174(7) Å and c = 11.9111(11) Å and is isostructural with the Al(III) analogue MFM-300(Al2) with pores decorated with -OH groups bridging Ga(III) centers. The isostructural Fe-doped material [Ga(1.87)Fe(0.13)(OH)2(L)], MFM-300(Ga(1.87)Fe(0.13)), can be prepared under similar conditions to MFM-300(Ga2) via reaction of a homogeneous mixture of Fe(NO3)3 and Ga(NO3)3 with biphenyl-3,3',5,5'-tetracarboxylic acid. An Fe(III)-based material [Fe3O(1.5)(OH)(HL)(L)(0.5)(H2O)(3.5)], MFM-310(Fe), was synthesized with Fe(NO3)3 and the same ligand via hydrothermal methods. [MFM-310(Fe)] crystallizes in the orthorhombic space group Pmn21 with a = 10.560(4) Å, b = 19.451(8) Å, and c = 11.773(5) Å and incorporates μ3-oxo-centered trinuclear iron cluster nodes connected by ligands to give a 3D nonporous framework that has a different structure to the MFM-300 series. Thus, Fe-doping can be used to monitor the effects of the heteroatom center within a parent Ga(III) framework without the requirement of synthesizing the isostructural Fe(III) analogue [Fe2(OH)2(L)], MFM-300(Fe2), which we have thus far been unable to prepare. Fe-doping of MFM-300(Ga2) affords positive effects on gas adsorption capacities, particularly for CO2 adsorption, whereby MFM-300(Ga(1.87)Fe(0.13)) shows a 49% enhancement of CO2 adsorption capacity in comparison to the homometallic parent material. We thus report herein the highest CO2 uptake (2.86 mmol g(-1) at 273 K at 1 bar) for a Ga-based MOF. The single-crystal X-ray structures of MFM-300(Ga2)-solv, MFM-300(Ga2), MFM-300(Ga2)·2.35CO2, MFM-300(Ga(1.87)Fe(0.13))-solv, MFM-300(Ga(1.87)Fe(0.13)), and MFM-300(Ga(1.87)Fe(0.13))·2.0CO2 have been determined. Most notably, in situ single-crystal diffraction studies of gas-loaded materials have revealed that Fe-doping has a significant impact on the molecular details for CO2 binding in the pore, with the bridging M-OH hydroxyl groups being preferred binding sites for CO2 within these framework materials. In situ synchrotron IR spectroscopic measurements on CO2 binding with respect to the -OH groups in the pore are consistent with the above structural analyses. In addition, we found that, compared to MFM-300(Ga2), Fe-doped MFM-300(Ga(1.87)Fe(0.13)) shows improved catalytic properties for the ring-opening reaction of styrene oxide, but similar activity for the room-temperature acetylation of benzaldehyde by methanol. The role of Fe-doping in these systems is discussed as a mechanism for enhancing porosity and the structural integrity of the parent material.
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Affiliation(s)
- Cristina P Krap
- School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K
| | - Ruth Newby
- School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K
| | - Amarajothi Dhakshinamoorthy
- Instituto de Technologia Quimica (UPV-CSIC), Universidad Politecnica de Valencia , Avenida de los Naranjos s/n, Valencia, 46022, Spain
| | - Hermenegildo García
- Instituto de Technologia Quimica (UPV-CSIC), Universidad Politecnica de Valencia , Avenida de los Naranjos s/n, Valencia, 46022, Spain
| | - Izabela Cebula
- School of Physics, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.,Department of Chemical and Process Engineering, University of Strathclyde , James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, U.K
| | - Timothy L Easun
- School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.,School of Chemistry, Cardiff University , Main Building, Park Place, Cardiff, CF10 3AT, U.K
| | - Mathew Savage
- School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K
| | - Jennifer E Eyley
- School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K
| | - Shan Gao
- School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K
| | - Alexander J Blake
- School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K
| | - William Lewis
- School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K
| | - Peter H Beton
- Instituto de Technologia Quimica (UPV-CSIC), Universidad Politecnica de Valencia , Avenida de los Naranjos s/n, Valencia, 46022, Spain
| | - Mark R Warren
- Diamond Light Source , Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, U.K
| | - David R Allan
- Diamond Light Source , Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, U.K
| | - Mark D Frogley
- Diamond Light Source , Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, U.K
| | - Chiu C Tang
- Diamond Light Source , Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, U.K
| | - Gianfelice Cinque
- Diamond Light Source , Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, U.K
| | - Sihai Yang
- School of Chemistry, University of Manchester , Oxford Road, Manchester, M13 9PL, U.K
| | - Martin Schröder
- School of Chemistry, University of Manchester , Oxford Road, Manchester, M13 9PL, U.K
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25
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Saywell A, Browning AS, Rahe P, Anderson HL, Beton PH. Organisation and ordering of 1D porphyrin polymers synthesised by on-surface Glaser coupling. Chem Commun (Camb) 2016; 52:10342-5. [DOI: 10.1039/c6cc03758e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
One-dimensional porphyrin polymer chains formed via on-surface Glaser coupling exhibit ordering and conformational flexibility.
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Affiliation(s)
- Alex Saywell
- School of Physics & Astronomy
- University of Nottingham
- Nottingham NG7 2RD
- UK
| | | | - Philipp Rahe
- School of Physics & Astronomy
- University of Nottingham
- Nottingham NG7 2RD
- UK
| | - Harry L. Anderson
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- UK
| | - Peter H. Beton
- School of Physics & Astronomy
- University of Nottingham
- Nottingham NG7 2RD
- UK
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26
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Korolkov VV, Svatek SA, Summerfield A, Kerfoot J, Yang L, Taniguchi T, Watanabe K, Champness NR, Besley NA, Beton PH. van der Waals-Induced Chromatic Shifts in Hydrogen-Bonded Two-Dimensional Porphyrin Arrays on Boron Nitride. ACS Nano 2015; 9:10347-10355. [PMID: 26348583 DOI: 10.1021/acsnano.5b04443] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The fluorescence of a two-dimensional supramolecular network of 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin (TCPP) adsorbed on hexagonal boron nitride (hBN) is red-shifted due to, primarily, adsorbate-substrate van der Waals interactions. TCPP is deposited from solution on hBN and forms faceted islands with typical dimensions of 100 nm and either square or hexagonal symmetry. The molecular arrangement is stabilized by in-plane hydrogen bonding as determined by a combination of molecular-resolution atomic force microscopy performed under ambient conditions and density functional theory; a similar structure is observed on MoS2 and graphite. The fluorescence spectra of submonolayers of TCPP on hBN are red-shifted by ∼30 nm due to the distortion of the molecule arising from van der Waals interactions, in agreement with time-dependent density functional theory calculations. Fluorescence intensity variations are observed due to coherent partial reflections at the hBN interface, implying that such hybrid structures have potential in photonic applications.
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Affiliation(s)
| | | | | | | | | | - Takashi Taniguchi
- The National Institute for Materials Science, Advanced Materials Laboratory , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- The National Institute for Materials Science, Advanced Materials Laboratory , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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27
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Summerfield A, Cebula I, Schröder M, Beton PH. Nucleation and Early Stages of Layer-by-Layer Growth of Metal Organic Frameworks on Surfaces. J Phys Chem C Nanomater Interfaces 2015; 119:23544-23551. [PMID: 26709359 PMCID: PMC4689388 DOI: 10.1021/acs.jpcc.5b07133] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/23/2015] [Indexed: 05/29/2023]
Abstract
High resolution atomic force microscopy (AFM) is used to resolve the evolution of crystallites of a metal organic framework (HKUST-1) grown on Au(111) using a liquid-phase layer-by-layer methodology. The nucleation and faceting of individual crystallites is followed by repeatedly imaging the same submicron region after each cycle of growth and we find that the growing surface is terminated by {111} facets leading to the formation of pyramidal nanostructures for [100] oriented crystallites, and triangular [111] islands with typical lateral dimensions of tens of nanometres. AFM images reveal that crystallites can grow by 5-10 layers in each cycle. The growth rate depends on crystallographic orientation and the morphology of the gold substrate, and we demonstrate that under these conditions the growth is nanocrystalline with a morphology determined by the minimum energy surface.
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Affiliation(s)
- Alex Summerfield
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Izabela Cebula
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
- School
of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, U.K.
- Institute of Experimental Physics, University of Wroclaw, Pl. M. Borna 9, 50-204 Wroclaw, Poland
| | - Martin Schröder
- School
of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, U.K.
| | - Peter H. Beton
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
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28
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Mudd GW, Svatek SA, Hague L, Makarovsky O, Kudrynskyi ZR, Mellor CJ, Beton PH, Eaves L, Novoselov KS, Kovalyuk ZD, Vdovin EE, Marsden AJ, Wilson NR, Patanè A. High broad-band photoresponsivity of mechanically formed InSe-graphene van der Waals heterostructures. Adv Mater 2015; 27:3760-6. [PMID: 25981798 PMCID: PMC4768130 DOI: 10.1002/adma.201500889] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/21/2015] [Indexed: 05/21/2023]
Abstract
High broad-band photoresponsivity of mechanically formed InSe-graphene van der Waals heterostructures is achieved by exploiting the broad-band transparency of graphene, the direct bandgap of InSe, and the favorable band line up of InSe with graphene. The photoresponsivity exceeds that for other van der Waals heterostructures and the spectral response extends from the near-infrared to the visible spectrum.
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Affiliation(s)
- Garry W Mudd
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Simon A Svatek
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Lee Hague
- School of Physics & Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Oleg Makarovsky
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Zakhar R Kudrynskyi
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Christopher J Mellor
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter H Beton
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Laurence Eaves
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
| | - Kostya S Novoselov
- School of Physics & Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Zakhar D Kovalyuk
- Institute for Problems of Materials Science, The National Academy of Sciences of Ukraine, Chernivtsi, 58001, Ukraine
| | - Evgeny E Vdovin
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
- Institute of Microelectronics Technology RAS, Chernogolovka, 142432, Russia
| | - Alex J Marsden
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - Neil R Wilson
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - Amalia Patanè
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, UK
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29
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Abstract
Advances in template-directed synthesis make it possible to create artificial molecules with protein-like dimensions, directly from simple components. These synthetic macromolecules have a proclivity for self-organization that is reminiscent of biopolymers. Here, we report the synthesis of monodisperse cyclic porphyrin polymers, with diameters of up to 21 nm (750 C–C bonds). The ratio of the intrinsic viscosities for cyclic and linear topologies is 0.72, indicating that these polymers behave as almost ideal flexible chains in solution. When deposited on gold surfaces, the cyclic polymers display a new mode of two-dimensional supramolecular organization, combining encapsulation and nesting; one nanoring adopts a near-circular conformation, thus allowing a second nanoring to be captured within its perimeter, in a tightly folded conformation. Scanning tunnelling microscopy reveals that nesting occurs in combination with stacking when nanorings are deposited under vacuum, whereas when they are deposited directly from solution under ambient conditions there is stacking or nesting, but not a combination of both.
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30
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Korolkov VV, Svatek SA, Allen S, Roberts CJ, Tendler SJB, Taniguchi T, Watanabe K, Champness NR, Beton PH. Bimolecular porous supramolecular networks deposited from solution on layered materials: graphite, boron nitride and molybdenum disulphide. Chem Commun (Camb) 2015; 50:8882-5. [PMID: 24969532 DOI: 10.1039/c4cc03720k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A two-dimensional porous network formed from perylene tetracarboxylic diimide (PTCDI) and melamine may be deposited from solution on the surfaces of highly oriented pyrolytic graphite (HOPG), hexagonal boron nitride (hBN) and molybdenum disulphide (MoS2). Images acquired using high resolution atomic force microscopy (AFM) operating under ambient conditions have revealed that the network forms extended ordered monolayers (>1 μm(2)) on HOPG and hBN whereas on MoS2 much smaller islands are observed.
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Affiliation(s)
- Vladimir V Korolkov
- School of Physics & Astronomy, The University of Nottingham, Nottingham NG7 2RD, UK.
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31
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Whitelam S, Tamblyn I, Garrahan JP, Beton PH. Emergent rhombus tilings from molecular interactions with M-fold rotational symmetry. Phys Rev Lett 2015; 114:115702. [PMID: 25839291 DOI: 10.1103/physrevlett.114.115702] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Indexed: 06/04/2023]
Abstract
We show that model molecules with particular rotational symmetries can self-assemble into network structures equivalent to rhombus tilings. This assembly happens in an emergent way, in the sense that molecules spontaneously select irregular fourfold local coordination from a larger set of possible local binding geometries. The existence of such networks can be rationalized by simple geometrical arguments, but the same arguments do not guarantee a network's spontaneous self-assembly. This class of structures must in certain regimes of parameter space be able to reconfigure into networks equivalent to triangular tilings.
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Affiliation(s)
- Stephen Whitelam
- Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Isaac Tamblyn
- Department of Physics, University of Ontario Institute of Technology, Oshawa, Ontario L1H 7K4, Canada
| | - Juan P Garrahan
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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32
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Svatek SA, Scott OR, Rivett JP, Wright K, Baldoni M, Bichoutskaia E, Taniguchi T, Watanabe K, Marsden AJ, Wilson NR, Beton PH. Adsorbate-induced curvature and stiffening of graphene. Nano Lett 2015; 15:159-164. [PMID: 25469625 PMCID: PMC4326047 DOI: 10.1021/nl503308c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 11/10/2014] [Indexed: 05/30/2023]
Abstract
The adsorption of the alkane tetratetracontane (TTC, C44H90) on graphene induces the formation of a curved surface stabilized by a gain in adsorption energy. This effect arises from a curvature-dependent variation of a moiré pattern due to the mismatch of the carbon-carbon separation in the adsorbed molecule and the period of graphene. The effect is observed when graphene is transferred onto a deformable substrate, which in our case is the interface between water layers adsorbed on mica and an organic solvent, but is not observed on more rigid substrates such as boron nitride. Our results show that molecular adsorption can be influenced by substrate curvature, provide an example of two-dimensional molecular self-assembly on a soft, responsive interface, and demonstrate that the mechanical properties of graphene may be modified by molecular adsorption, which is of relevance to nanomechanical systems, electronics, and membrane technology.
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Affiliation(s)
- Simon A. Svatek
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Oliver R. Scott
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Jasmine P.H. Rivett
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Katherine Wright
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Matteo Baldoni
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Elena Bichoutskaia
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Takashi Taniguchi
- The National Institute for Materials Science,
Advanced Materials Laboratory, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- The National Institute for Materials Science,
Advanced Materials Laboratory, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | | | - Neil R. Wilson
- Department
of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Peter H. Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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33
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Abstract
CONSPECTUS: The arrangement of molecular species into extended structures remains the focus of much current chemical science. The organization of molecules on surfaces using intermolecular interactions has been studied to a lesser degree than solution or solid-state systems, and unanticipated observations still lie in store. Intermolecular hydrogen bonds are an attractive tool that can be used to facilitate the self-assembly of an extended structure through the careful design of target building blocks. Our studies have focused on the use of 3,4,9,10-perylene tetracarboxylic acid diimides (PTCDIs), and related functionalized analogues, to prepare extended arrays on surfaces. These molecules are ideal for such studies because they are specifically designed to interact with appropriate diaminopyridine-functionalized molecules, and related species, through complementary hydrogen bonds. Additionally, PTCDI species can be functionalized in the bay region of the molecule, facilitating modification of the self-assembled structures that can be prepared. Through a combination of PTCDI derivatives, sometimes in combination with melamine, porous two-dimensional arrays can be formed that can entrap guest molecules. The factors that govern the self-assembly processes of PTCDI derivatives are discussed, and the ability to construct suitable target arrays and host-specific molecular species, including fullerenes and transition metal clusters, is demonstrated.
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Affiliation(s)
- Anna G. Slater
- School of Chemistry, ‡School of Physics
and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Luis M. A. Perdigão
- School of Chemistry, ‡School of Physics
and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Peter H. Beton
- School of Chemistry, ‡School of Physics
and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Neil R. Champness
- School of Chemistry, ‡School of Physics
and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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34
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Yong CK, Parkinson P, Kondratuk DV, Chen WH, Stannard A, Summerfield A, Sprafke JK, O'Sullivan MC, Beton PH, Anderson HL, Herz LM. Ultrafast delocalization of excitation in synthetic light-harvesting nanorings. Chem Sci 2014; 6:181-189. [PMID: 28553466 PMCID: PMC5424671 DOI: 10.1039/c4sc02424a] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [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: 08/10/2014] [Accepted: 09/16/2014] [Indexed: 11/21/2022] Open
Abstract
When light is absorbed by a nanoring consisting of 6–24 porphyrin units, the excitation delocalizes over the whole molecule within 200 fs. Highly symmetric nanorings exhibit thermally enhanced super-radiance.
Rings of chlorophyll molecules harvest sunlight remarkably efficiently during photosynthesis in purple bacteria. The key to their efficiency lies in their highly delocalized excited states that allow for ultrafast energy migration. Here we show that a family of synthetic nanorings mimic the ultrafast energy transfer and delocalization observed in nature. π-Conjugated nanorings with diameters of up to 10 nm, consisting of up to 24 porphyrin units, are found to exhibit excitation delocalization within the first 200 fs of light absorption. Transitions from the first singlet excited state of the circular nanorings are dipole-forbidden as a result of symmetry constraints, but these selection rules can be lifted through static and dynamic distortions of the rings. The increase in the radiative emission rate in the larger nanorings correlates with an increase in static disorder expected from Monte Carlo simulations. For highly symmetric rings, the radiative rate is found to increase with increasing temperature. Although this type of thermally activated superradiance has been theoretically predicted in circular chromophore arrays, it has not previously been observed in any natural or synthetic systems. As expected, the activation energy for emission increases when a nanoring is fixed in a circular conformation by coordination to a radial template. These nanorings offer extended chromophores with high excitation delocalization that is remarkably stable against thermally induced disorder. Such findings open new opportunities for exploring coherence effects in nanometer molecular rings and for implementing these biomimetic light-harvesters in man-made devices.
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Affiliation(s)
- Chaw-Keong Yong
- University of Oxford , Department of Physics , Clarendon Laboratory , Parks Road , Oxford , OX1 3PU , UK .
| | - Patrick Parkinson
- University of Oxford , Department of Physics , Clarendon Laboratory , Parks Road , Oxford , OX1 3PU , UK .
| | - Dmitry V Kondratuk
- University of Oxford , Department of Chemistry , Chemistry Research Laboratory , Oxford , OX1 3TA , UK .
| | - Wei-Hsin Chen
- University of Oxford , Department of Physics , Clarendon Laboratory , Parks Road , Oxford , OX1 3PU , UK .
| | - Andrew Stannard
- School of Physics & Astronomy , University of Nottingham , Nottingham , NG7 2RD , UK
| | - Alex Summerfield
- School of Physics & Astronomy , University of Nottingham , Nottingham , NG7 2RD , UK
| | - Johannes K Sprafke
- University of Oxford , Department of Chemistry , Chemistry Research Laboratory , Oxford , OX1 3TA , UK .
| | - Melanie C O'Sullivan
- University of Oxford , Department of Chemistry , Chemistry Research Laboratory , Oxford , OX1 3TA , UK .
| | - Peter H Beton
- School of Physics & Astronomy , University of Nottingham , Nottingham , NG7 2RD , UK
| | - Harry L Anderson
- University of Oxford , Department of Chemistry , Chemistry Research Laboratory , Oxford , OX1 3TA , UK .
| | - Laura M Herz
- University of Oxford , Department of Physics , Clarendon Laboratory , Parks Road , Oxford , OX1 3PU , UK .
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35
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Kondratuk DV, Sprafke JK, O'Sullivan MC, Perdigao LMA, Saywell A, Malfois M, O'Shea JN, Beton PH, Thompson AL, Anderson HL. Vernier-templated synthesis, crystal structure, and supramolecular chemistry of a 12-porphyrin nanoring. Chemistry 2014; 20:12826-34. [PMID: 25154736 PMCID: PMC4517159 DOI: 10.1002/chem.201403714] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Indexed: 01/08/2023]
Abstract
Vernier templating exploits a mismatch between the number of binding sites in a template and a reactant to direct the formation of a product that is large enough to bind several template units. Here, we present a detailed study of the Vernier-templated synthesis of a 12-porphyrin nanoring. NMR and small-angle X-ray scattering (SAXS) analyses show that Vernier complexes are formed as intermediates in the cyclo-oligomerization reaction. UV/Vis/NIR titrations show that the three-component assembly of the 12-porphyrin nanoring figure-of-eight template complex displays high allosteric cooperativity and chelate cooperativity. This nanoring–template 1:2 complex is among the largest synthetic molecules to have been characterized by single-crystal analysis. It crystallizes as a racemate, with an angle of 27° between the planes of the two template units. The crystal structure reveals many unexpected intramolecular C–H⋅⋅⋅N contacts involving the tert-butyl side chains. Scanning tunneling microscopy (STM) experiments show that molecules of the 12-porphyrin template complex can remain intact on the gold surface, although the majority of the material unfolds into the free nanoring during electrospray deposition.
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Affiliation(s)
- Dmitry V Kondratuk
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
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36
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Wieland MB, Slater AG, Mangham B, Champness NR, Beton PH. Fullerenes as adhesive layers for mechanical peeling of metallic, molecular and polymer thin films. Beilstein J Nanotechnol 2014; 5:394-401. [PMID: 24778965 PMCID: PMC3999765 DOI: 10.3762/bjnano.5.46] [Citation(s) in RCA: 5] [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] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/10/2014] [Indexed: 06/03/2023]
Abstract
We show that thin films of C60 with a thickness ranging from 10 to 100 nm can promote adhesion between a Au thin film deposited on mica and a solution-deposited layer of the elastomer polymethyldisolaxane (PDMS). This molecular adhesion facilitates the removal of the gold film from the mica support by peeling and provides a new approach to template stripping which avoids the use of conventional adhesive layers. The fullerene adhesion layers may also be used to remove organic monolayers and thin films as well as two-dimensional polymers which are pre-formed on the gold surface and have monolayer thickness. Following the removal from the mica support the monolayers may be isolated and transferred to a dielectric surface by etching of the gold thin film, mechanical transfer and removal of the fullerene layer by annealing/dissolution. The use of this molecular adhesive layer provides a new route to transfer polymeric films from metal substrates to other surfaces as we demonstrate for an assembly of covalently-coupled porphyrins.
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Affiliation(s)
- Maria B Wieland
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Anna G Slater
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
- Present address: Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | - Barry Mangham
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Neil R Champness
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter H Beton
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
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37
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Wieland MB, Perdigão LMA, Kondratuk DV, O’Shea JN, Anderson HL, Beton PH. Height dependent molecular trapping in stacked cyclic porphyrin nanorings. Chem Commun (Camb) 2014; 50:7332-5. [DOI: 10.1039/c4cc02629b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stacked cyclic porphyrin nanorings function as traps for fullerene molecules dependent on stack height and diameter of the nanoring.
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Affiliation(s)
- Maria B. Wieland
- School of Physics and Astronomy
- University of Nottingham
- Nottingham, UK
| | | | - Dmitry V. Kondratuk
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford, UK
| | - James N. O’Shea
- School of Physics and Astronomy
- University of Nottingham
- Nottingham, UK
| | - Harry L. Anderson
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford, UK
| | - Peter H. Beton
- School of Physics and Astronomy
- University of Nottingham
- Nottingham, UK
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38
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Mudd GW, Svatek SA, Ren T, Patanè A, Makarovsky O, Eaves L, Beton PH, Kovalyuk ZD, Lashkarev GV, Kudrynskyi ZR, Dmitriev AI. Tuning the bandgap of exfoliated InSe nanosheets by quantum confinement. Adv Mater 2013; 25:5714-8. [PMID: 23966225 PMCID: PMC4065344 DOI: 10.1002/adma.201302616] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/09/2013] [Indexed: 05/21/2023]
Abstract
Strong quantization effects and tuneable near-infrared photoluminescence emission are reported in mechanically exfoliated crystals of γ-rhombohedral semiconducting InSe. The optical properties of InSe nanosheets differ qualitatively from those reported recently for exfoliated transition metal dichalcogenides and indicate a crossover from a direct to an indirect band gap semiconductor when the InSe flake thickness is reduced to a few nanometers.
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Affiliation(s)
- Garry W Mudd
- School of Physics and Astronomy The University of NottinghamNottingham, NG7 2RD, UK E-mail:
| | - Simon A Svatek
- School of Physics and Astronomy The University of NottinghamNottingham, NG7 2RD, UK E-mail:
| | - Tianhang Ren
- School of Physics and Astronomy The University of NottinghamNottingham, NG7 2RD, UK E-mail:
| | - Amalia Patanè
- School of Physics and Astronomy The University of NottinghamNottingham, NG7 2RD, UK E-mail:
| | - Oleg Makarovsky
- School of Physics and Astronomy The University of NottinghamNottingham, NG7 2RD, UK E-mail:
| | - Laurence Eaves
- School of Physics and Astronomy The University of NottinghamNottingham, NG7 2RD, UK E-mail:
| | - Peter H Beton
- School of Physics and Astronomy The University of NottinghamNottingham, NG7 2RD, UK E-mail:
| | - Zakhar D Kovalyuk
- Institute for Problems of Materials Science Ukrainian Academy of SciencesKiev, Ukraine
| | - George V Lashkarev
- Institute for Problems of Materials Science Ukrainian Academy of SciencesKiev, Ukraine
| | - Zakhar R Kudrynskyi
- Institute for Problems of Materials Science Ukrainian Academy of SciencesKiev, Ukraine
| | - Alexandr I Dmitriev
- Institute for Problems of Materials Science Ukrainian Academy of SciencesKiev, Ukraine
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39
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Cebula I, Smith E, Gimenez-Lopez MC, Yang S, Schröder M, Champness NR, Beton PH. Packing of Isophthalate Tetracarboxylic Acids on Au(111): Rows and Disordered Herringbone Structures. J Phys Chem C Nanomater Interfaces 2013; 117:18381-18385. [PMID: 24163714 PMCID: PMC3806148 DOI: 10.1021/jp402333m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 08/14/2013] [Indexed: 06/02/2023]
Abstract
Scanning tunnelling microscopy (STM) has been used to investigate the formation of hydrogen-bonded structures of the isophthalate tetracarboxylic acids, biphenyl-3,3',5,5'-tetracarboxylic acid (BPTC), terphenyl-3,3″,5,5″-tetracarboxylic acid (TPTC), and quarterphenyl-3,3‴,5,5‴-tetracarboxylic acid (QPTC), via deposition from solution onto Au(111). STM data reveal that ordered structures can be formed from an aqueous solution leading to the formation of rows for the shortest acid BPTC, while the longer molecules TPTC and QPTC adopt a herringbone-like structure with significant degrees of disorder. The influence of solvent and substrate on the molecular ordering is discussed, and density functional theory is used to identify molecular models for these new phases.
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Affiliation(s)
- Izabela Cebula
- School of Physics and Astronomy and School of Chemistry, University of Nottingham, University
Park, Nottingham, NG7 2RD, U.K.
- Institute
of Experimental Physics, University of Wroclaw, Pl. M. Borna 9, 50-204 Wroclaw, Poland
| | - Emily
F. Smith
- School of Physics and Astronomy and School of Chemistry, University of Nottingham, University
Park, Nottingham, NG7 2RD, U.K.
| | - Maria
del Carmen Gimenez-Lopez
- School of Physics and Astronomy and School of Chemistry, University of Nottingham, University
Park, Nottingham, NG7 2RD, U.K.
| | - Sihai Yang
- School of Physics and Astronomy and School of Chemistry, University of Nottingham, University
Park, Nottingham, NG7 2RD, U.K.
| | - Martin Schröder
- School of Physics and Astronomy and School of Chemistry, University of Nottingham, University
Park, Nottingham, NG7 2RD, U.K.
| | - Neil R. Champness
- School of Physics and Astronomy and School of Chemistry, University of Nottingham, University
Park, Nottingham, NG7 2RD, U.K.
| | - Peter H. Beton
- School of Physics and Astronomy and School of Chemistry, University of Nottingham, University
Park, Nottingham, NG7 2RD, U.K.
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40
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Svatek S, Perdigão LMA, Stannard A, Wieland MB, Kondratuk DV, Anderson HL, O’Shea JN, Beton PH. Mechanical stiffening of porphyrin nanorings through supramolecular columnar stacking. Nano Lett 2013; 13:3391-5. [PMID: 23789845 PMCID: PMC3709264 DOI: 10.1021/nl4017557] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 06/18/2013] [Indexed: 05/22/2023]
Abstract
Solvent-induced aggregates of nanoring cyclic polymers may be transferred by electrospray deposition to a surface where they adsorb as three-dimensional columnar stacks. The observed stack height varies from single rings to four stacked rings with a layer spacing of 0.32 ± 0.04 nm as measured using scanning tunneling microscopy. The flexibility of the nanorings results in distortions from a circular shape, and we show, through a comparison with Monte Carlo simulations, that the bending stiffness increases linearly with the stack height. Our results show that noncovalent interactions may be used to control the shape and mechanical properties of artificial macromolecular aggregates offering a new route to solvent-induced control of two-dimensional supramolecular organization.
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Affiliation(s)
- Simon
A. Svatek
- School of
Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, United
Kingdom
| | - Luis M. A. Perdigão
- School of
Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, United
Kingdom
| | - Andrew Stannard
- School of
Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, United
Kingdom
| | - Maria B. Wieland
- School of
Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, United
Kingdom
| | - Dmitry V. Kondratuk
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory,
Oxford, OX1 3TA, United Kingdom
| | - Harry L. Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory,
Oxford, OX1 3TA, United Kingdom
| | - James N. O’Shea
- School of
Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, United
Kingdom
| | - Peter H. Beton
- School of
Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, United
Kingdom
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41
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Eder G, Smith EF, Cebula I, Heckl WM, Beton PH, Lackinger M. Solution preparation of two-dimensional covalently linked networks by polymerization of 1,3,5-Tri(4-iodophenyl)benzene on Au(111). ACS Nano 2013; 7:3014-3021. [PMID: 23472582 DOI: 10.1021/nn400337v] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [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
The polymerization of 1,3,5-tri(4-iodophenyl)benzene (TIPB) on Au(111) through covalent aryl-aryl coupling is accomplished using a solution-based approach and investigated by scanning tunneling microscopy. Drop-casting of the TIPB monomer onto Au(111) at room temperature results in poorly ordered noncovalent arrangements of molecules and partial dehalogenation. However, drop-casting on a preheated Au(111) substrate yields various topologically distinct covalent aggregates and networks. Interestingly, some of these covalent nanostructures do not adsorb directly on the Au(111) surface, but are loosely bound to a disordered layer of a mixture of chemisorbed iodine and molecules, a conclusion that is drawn from STM data and supported by X-ray photoelectron spectroscopy. We argue that the gold surface becomes covered by a strongly chemisorbed iodine monolayer which eventually inhibits further polymerization.
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Affiliation(s)
- Georg Eder
- TUM School of Education and Center for NanoScience (CeNS), Tech Univ Munich, Schellingstrasse 33, 80799 Munich, Germany
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42
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Kondratuk DV, Perdigao LMA, O'Sullivan MC, Svatek S, Smith G, O'Shea JN, Beton PH, Anderson HL. Two Vernier-Templated Routes to a 24-Porphyrin Nanoring. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201202870] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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43
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Kondratuk DV, Perdigao LMA, O'Sullivan MC, Svatek S, Smith G, O'Shea JN, Beton PH, Anderson HL. Two Vernier-Templated Routes to a 24-Porphyrin Nanoring. Angew Chem Int Ed Engl 2012; 51:6696-9. [DOI: 10.1002/anie.201202870] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Indexed: 11/11/2022]
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44
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Phillips AG, Beton PH, Champness NR. Two-Dimensional Supramolecular Chemistry. Supramol Chem 2012. [DOI: 10.1002/9780470661345.smc202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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45
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Abstract
We study the covering of the plane by nonoverlapping rhombus tiles, a problem well studied only in the limiting case of dimer coverings of regular lattices. We go beyond this limit by allowing tiles to take any position and orientation on the plane, to be of irregular shape, and to possess different types of attractive interactions. Using extensive numerical simulations, we show that at large tile densities there is a phase transition from a fluid of rhombus tiles to a solid packing with broken rotational symmetry. We observe self-assembly of broken-symmetry phases, even at low densities, in the presence of attractive tile-tile interactions. Depending on the tile shape and interactions, the solid phase can be random, possessing critical orientational fluctuations, or crystalline. Our results suggest strategies for controlling tiling order in experiments involving "molecular rhombi."
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Affiliation(s)
- Stephen Whitelam
- Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
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Stannard A, Russell JC, Blunt MO, Salesiotis C, Giménez-López MDC, Taleb N, Schröder M, Champness NR, Garrahan JP, Beton PH. Broken symmetry and the variation of critical properties in the phase behaviour of supramolecular rhombus tilings. Nat Chem 2011; 4:112-7. [PMID: 22270626 DOI: 10.1038/nchem.1199] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 10/12/2011] [Indexed: 11/09/2022]
Abstract
The tiling of surfaces has long attracted the attention of scientists, not only because it is intriguing intrinsically, but also as a way to control the properties of surfaces. However, although random tiling networks are studied increasingly, their degree of randomness (or partial order) has remained notoriously difficult to control, in common with other supramolecular systems. Here we show that the random organization of a two-dimensional supramolecular array of isophthalate tetracarboxylic acids varies with subtle chemical changes in the system. We quantify this variation using an order parameter and reveal a phase behaviour that is consistent with long-standing theoretical studies on random tiling. The balance between order and randomness is driven by small differences in intermolecular interaction energies, which can be related by numerical simulations to the experimentally measured order parameter. Significant variations occur with very small energy differences, which highlights the delicate balance between entropic and energetic effects in complex self-assembly processes.
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Affiliation(s)
- Andrew Stannard
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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Russell JC, Blunt MO, Garfitt JM, Scurr DJ, Alexander M, Champness NR, Beton PH. Dimerization of Tri(4-bromophenyl)benzene by Aryl−Aryl Coupling from Solution on a Gold Surface. J Am Chem Soc 2011; 133:4220-3. [DOI: 10.1021/ja110837s] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- James C. Russell
- School of Physics & Astronomy, ‡School of Pharmacy, and §School of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Matthew O. Blunt
- School of Physics & Astronomy, ‡School of Pharmacy, and §School of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Jason M. Garfitt
- School of Physics & Astronomy, ‡School of Pharmacy, and §School of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - David J. Scurr
- School of Physics & Astronomy, ‡School of Pharmacy, and §School of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Morgan Alexander
- School of Physics & Astronomy, ‡School of Pharmacy, and §School of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Neil R. Champness
- School of Physics & Astronomy, ‡School of Pharmacy, and §School of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Peter H. Beton
- School of Physics & Astronomy, ‡School of Pharmacy, and §School of Chemistry, University of Nottingham, Nottingham NG7 2RD, U.K
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Saywell A, Britton AJ, Taleb N, Giménez-López MDC, Champness NR, Beton PH, O'Shea JN. Single molecule magnets on a gold surface: in situ electrospray deposition, x-ray absorption and photoemission. Nanotechnology 2011; 22:075704. [PMID: 21233552 DOI: 10.1088/0957-4484/22/7/075704] [Citation(s) in RCA: 11] [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: 05/30/2023]
Abstract
Single molecule magnets based on the dodecamanganese (III, IV) cluster with two different types of ligand (acetate and benzoate) have been studied on the Au(111) surface. Due to the non-volatile and fragile nature of the molecules, we have used ultra-high vacuum electrospray deposition to produce a series of surface coverages from a fraction of a monolayer to multilayer films in both cases. Synchrotron radiation based electron spectroscopy has been used to study the adsorption of the molecules on the Au(111) surface and the effect that this has on the oxidation states of the manganese atoms in the core. In both cases, reduction of the core is observed due to the interaction with the surface, to essentially the same extent despite substantial differences in the size and nature of the ligand shell.
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Affiliation(s)
- Alex Saywell
- School of Physics and Astronomy, University of Nottingham, Nottingham, UK
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Blunt MO, Russell JC, Gimenez-Lopez MDC, Taleb N, Lin X, Schröder M, Champness NR, Beton PH. Guest-induced growth of a surface-based supramolecular bilayer. Nat Chem 2010; 3:74-8. [PMID: 21160521 DOI: 10.1038/nchem.901] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 10/07/2010] [Indexed: 12/20/2022]
Abstract
Self-assembly of planar molecules on a surface can result in the formation of a wide variety of close-packed or porous structures. Two-dimensional porous arrays provide host sites for trapping guest species of suitable size. Here we show that a non-planar guest species (C(60)) can play a more complex role by promoting the growth of a second layer of host molecules (p-terphenyl-3,5,3″,5″-tetracarboxylic acid) above and parallel to the surface so that self-assembly is extended into the third dimension. The addition of guest molecules and the formation of the second layer are co-dependent. Adding a planar guest (coronene) can displace the C(60) and cause reversion to a monolayer arrangement. The system provides an example of a reversible transformation between a planar and a non-planar supramolecular network, an important step towards the controlled self-assembly of functional, three-dimensional, surface-based supramolecular architectures.
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Affiliation(s)
- Matthew O Blunt
- School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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