1
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Li C, Kaspar C, Zhou P, Liu JC, Chahib O, Glatzel T, Häner R, Aschauer U, Decurtins S, Liu SX, Thoss M, Meyer E, Pawlak R. Strong signature of electron-vibration coupling in molecules on Ag(111) triggered by tip-gated discharging. Nat Commun 2023; 14:5956. [PMID: 37749099 PMCID: PMC10519934 DOI: 10.1038/s41467-023-41601-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 09/05/2023] [Indexed: 09/27/2023] Open
Abstract
Electron-vibration coupling is of critical importance for the development of molecular electronics, spintronics, and quantum technologies, as it affects transport properties and spin dynamics. The control over charge-state transitions and subsequent molecular vibrations using scanning tunneling microscopy typically requires the use of a decoupling layer. Here we show the vibronic excitations of tetrabromotetraazapyrene (TBTAP) molecules directly adsorbed on Ag(111) into an orientational glassy phase. The electron-deficient TBTAP is singly-occupied by an electron donated from the substrate, resulting in a spin 1/2 state, which is confirmed by a Kondo resonance. The TBTAP•- discharge is controlled by tip-gating and leads to a series of peaks in scanning tunneling spectroscopy. These occurrences are explained by combining a double-barrier tunneling junction with a Franck-Condon model including molecular vibrational modes. This work demonstrates that suitable precursor design enables gate-dependent vibrational excitations of molecules on a metal, thereby providing a method to investigate electron-vibration coupling in molecular assemblies without a decoupling layer.
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Affiliation(s)
- Chao Li
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056, Basel, Switzerland.
| | - Christoph Kaspar
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg, Germany
| | - Ping Zhou
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Jung-Ching Liu
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056, Basel, Switzerland
| | - Outhmane Chahib
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056, Basel, Switzerland
| | - Thilo Glatzel
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056, Basel, Switzerland
| | - Robert Häner
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Ulrich Aschauer
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
- Department of Chemistry and Physics of Materials, University of Salzburg, Jakob-Haringer-Strasse 2A, 5020 Salzburg, Austria
| | - Silvio Decurtins
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Shi-Xia Liu
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland.
| | - Michael Thoss
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg, Germany
- EUCOR Centre for Quantum Science and Quantum Computing, University of Freiburg, Hermann-Herder-Str. 3, 79104, Freiburg, Germany
| | - Ernst Meyer
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056, Basel, Switzerland.
| | - Rémy Pawlak
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056, Basel, Switzerland.
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2
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Haags A, Yang X, Egger L, Brandstetter D, Kirschner H, Bocquet FC, Koller G, Gottwald A, Richter M, Gottfried JM, Ramsey MG, Puschnig P, Soubatch S, Tautz FS. Momentum space imaging of σ orbitals for chemical analysis. SCIENCE ADVANCES 2022; 8:eabn0819. [PMID: 35867796 PMCID: PMC9307240 DOI: 10.1126/sciadv.abn0819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
Tracing the modifications of molecules in surface chemical reactions benefits from the possibility to image their orbitals. While delocalized frontier orbitals with π character are imaged routinely with photoemission orbital tomography, they are not always sensitive to local chemical modifications, particularly the making and breaking of bonds at the molecular periphery. For such bonds, σ orbitals would be far more revealing. Here, we show that these orbitals can indeed be imaged in a remarkably broad energy range and that the plane wave approximation, an important ingredient of photoemission orbital tomography, is also well fulfilled for these orbitals. This makes photoemission orbital tomography a unique tool for the detailed analysis of surface chemical reactions. We demonstrate this by identifying the reaction product of a dehalogenation and cyclodehydrogenation reaction.
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Affiliation(s)
- Anja Haags
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Aachen, Germany
| | - Xiaosheng Yang
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Aachen, Germany
| | - Larissa Egger
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, Graz, Austria
| | | | - Hans Kirschner
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - François C. Bocquet
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, Jülich, Germany
| | - Georg Koller
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, Graz, Austria
| | | | - Mathias Richter
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | | | - Michael G. Ramsey
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, Graz, Austria
| | - Peter Puschnig
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, Graz, Austria
| | - Serguei Soubatch
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, Jülich, Germany
| | - F. Stefan Tautz
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, Aachen, Germany
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3
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Resonant Photoemission Spectroscopy of Highly-Oriented-Coronene Monolayer using Photoelectron Momentum Microscope. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2022. [DOI: 10.1380/ejssnt.2022-031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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4
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Ultrafast orbital tomography of a pentacene film using time-resolved momentum microscopy at a FEL. Nat Commun 2022; 13:2741. [PMID: 35585096 PMCID: PMC9117673 DOI: 10.1038/s41467-022-30404-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 04/28/2022] [Indexed: 11/24/2022] Open
Abstract
Time-resolved momentum microscopy provides insight into the ultrafast interplay between structural and electronic dynamics. Here we extend orbital tomography into the time domain in combination with time-resolved momentum microscopy at a free-electron laser (FEL) to follow transient photoelectron momentum maps of excited states of a bilayer pentacene film on Ag(110). We use optical pump and FEL probe pulses by keeping FEL source conditions to minimize space charge effects and radiation damage. From the momentum microscopy signal, we obtain time-dependent momentum maps of the excited-state dynamics of both pentacene layers separately. In a combined experimental and theoretical study, we interpret the observed signal for the bottom layer as resulting from the charge redistribution between the molecule and the substrate induced by excitation. We identify that the dynamics of the top pentacene layer resembles excited-state molecular dynamics. Ultrafast pulses are useful to investigate the electron dynamics in excited atoms, molecules and other complex systems. Here, the authors measure transient photoelectron momentum maps following the free-electron laser pulse-induced ionization of a bilayer pentacene thin film on Ag (110) by using time-resolved orbital tomography.
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5
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Schönhense G, Babenkov S, Vasilyev D, Elmers HJ, Medjanik K. Single-hemisphere photoelectron momentum microscope with time-of-flight recording. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:123110. [PMID: 33379996 DOI: 10.1063/5.0024074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/26/2020] [Indexed: 06/12/2023]
Abstract
Photoelectron momentum microscopy is an emerging powerful method for angle-resolved photoelectron spectroscopy (ARPES), especially in combination with imaging spin filters. These instruments record kx-ky images, typically exceeding a full Brillouin zone. As energy filters, double-hemispherical or time-of-flight (ToF) devices are in use. Here, we present a new approach for momentum mapping of the full half-space, based on a large single hemispherical analyzer (path radius of 225 mm). Excitation by an unfocused He lamp yielded an energy resolution of 7.7 meV. The performance is demonstrated by k-imaging of quantum-well states in Au and Xe multilayers. The α2-aberration term (α, entrance angle in the dispersive plane) and the transit-time spread of the electrons in the spherical field are studied in a large pass-energy (6 eV-660 eV) and angular range (α up to ±7°). It is discussed how the method circumvents the preconditions of previous theoretical work on the resolution limitation due to the α2-term and the transit-time spread, being detrimental for time-resolved experiments. Thanks to k-resolved detection, both effects can be corrected numerically. We introduce a dispersive-plus-ToF hybrid mode of operation, with an imaging ToF analyzer behind the exit slit of the hemisphere. This instrument captures 3D data arrays I (EB, kx, ky), yielding a gain up to N2 in recording efficiency (N being the number of resolved time slices). A key application will be ARPES at sources with high pulse rates such as synchrotrons with 500 MHz time structure.
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Affiliation(s)
- G Schönhense
- Johannes Gutenberg-Universität, Institut für Physik, 55128 Mainz, Germany
| | - S Babenkov
- Johannes Gutenberg-Universität, Institut für Physik, 55128 Mainz, Germany
| | - D Vasilyev
- Johannes Gutenberg-Universität, Institut für Physik, 55128 Mainz, Germany
| | - H-J Elmers
- Johannes Gutenberg-Universität, Institut für Physik, 55128 Mainz, Germany
| | - K Medjanik
- Johannes Gutenberg-Universität, Institut für Physik, 55128 Mainz, Germany
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6
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Haags A, Reichmann A, Fan Q, Egger L, Kirschner H, Naumann T, Werner S, Vollgraff T, Sundermeyer J, Eschmann L, Yang X, Brandstetter D, Bocquet FC, Koller G, Gottwald A, Richter M, Ramsey MG, Rohlfing M, Puschnig P, Gottfried JM, Soubatch S, Tautz FS. Kekulene: On-Surface Synthesis, Orbital Structure, and Aromatic Stabilization. ACS NANO 2020; 14:15766-15775. [PMID: 33186031 PMCID: PMC7690051 DOI: 10.1021/acsnano.0c06798] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 11/03/2020] [Indexed: 05/08/2023]
Abstract
We revisit the question of kekulene's aromaticity by focusing on the electronic structure of its frontier orbitals as determined by angle-resolved photoemission spectroscopy. To this end, we have developed a specially designed precursor, 1,4,7(2,7)-triphenanthrenacyclononaphane-2,5,8-triene, which allows us to prepare sufficient quantities of kekulene of high purity directly on a Cu(111) surface, as confirmed by scanning tunneling microscopy. Supported by density functional calculations, we determine the orbital structure of kekulene's highest occupied molecular orbital by photoemission tomography. In agreement with a recent aromaticity assessment of kekulene based solely on C-C bond lengths, we conclude that the π-conjugation of kekulene is better described by the Clar model rather than a superaromatic model. Thus, by exploiting the capabilities of photoemission tomography, we shed light on the question which consequences aromaticity holds for the frontier electronic structure of a π-conjugated molecule.
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Affiliation(s)
- Anja Haags
- Peter
Grünberg Institut (PGI-3), Forschungszentrum
Jülich, 52425 Jülich, Germany
- Jülich
Aachen Research Alliance (JARA), Fundamentals of Future Information
Technology, 52425 Jülich, Germany
- Experimentalphysik
IV A, RWTH Aachen University, 52074 Aachen, Germany
| | - Alexander Reichmann
- Institut
für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - Qitang Fan
- Fachbereich
Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Larissa Egger
- Institut
für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - Hans Kirschner
- Physikalisch-Technische
Bundesanstalt (PTB), 10587 Berlin, Germany
| | - Tim Naumann
- Fachbereich
Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Simon Werner
- Fachbereich
Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Tobias Vollgraff
- Fachbereich
Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Jörg Sundermeyer
- Fachbereich
Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Lukas Eschmann
- Institut
für Festkörpertheorie, Westfälische
Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Xiaosheng Yang
- Peter
Grünberg Institut (PGI-3), Forschungszentrum
Jülich, 52425 Jülich, Germany
- Jülich
Aachen Research Alliance (JARA), Fundamentals of Future Information
Technology, 52425 Jülich, Germany
- Experimentalphysik
IV A, RWTH Aachen University, 52074 Aachen, Germany
| | - Dominik Brandstetter
- Institut
für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - François C. Bocquet
- Peter
Grünberg Institut (PGI-3), Forschungszentrum
Jülich, 52425 Jülich, Germany
- Jülich
Aachen Research Alliance (JARA), Fundamentals of Future Information
Technology, 52425 Jülich, Germany
| | - Georg Koller
- Institut
für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | | | - Mathias Richter
- Physikalisch-Technische
Bundesanstalt (PTB), 10587 Berlin, Germany
| | - Michael G. Ramsey
- Institut
für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - Michael Rohlfing
- Institut
für Festkörpertheorie, Westfälische
Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Peter Puschnig
- Institut
für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - J. Michael Gottfried
- Fachbereich
Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Serguei Soubatch
- Peter
Grünberg Institut (PGI-3), Forschungszentrum
Jülich, 52425 Jülich, Germany
- Jülich
Aachen Research Alliance (JARA), Fundamentals of Future Information
Technology, 52425 Jülich, Germany
| | - F. Stefan Tautz
- Peter
Grünberg Institut (PGI-3), Forschungszentrum
Jülich, 52425 Jülich, Germany
- Jülich
Aachen Research Alliance (JARA), Fundamentals of Future Information
Technology, 52425 Jülich, Germany
- Experimentalphysik
IV A, RWTH Aachen University, 52074 Aachen, Germany
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7
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Haags A, Reichmann A, Fan Q, Egger L, Kirschner H, Naumann T, Werner S, Vollgraff T, Sundermeyer J, Eschmann L, Yang X, Brandstetter D, Bocquet FC, Koller G, Gottwald A, Richter M, Ramsey MG, Rohlfing M, Puschnig P, Gottfried JM, Soubatch S, Tautz FS. Kekulene: On-Surface Synthesis, Orbital Structure, and Aromatic Stabilization. ACS NANO 2020; 14:15766-15775. [PMID: 33186031 DOI: 10.26434/chemrxiv.12771254.v1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We revisit the question of kekulene's aromaticity by focusing on the electronic structure of its frontier orbitals as determined by angle-resolved photoemission spectroscopy. To this end, we have developed a specially designed precursor, 1,4,7(2,7)-triphenanthrenacyclononaphane-2,5,8-triene, which allows us to prepare sufficient quantities of kekulene of high purity directly on a Cu(111) surface, as confirmed by scanning tunneling microscopy. Supported by density functional calculations, we determine the orbital structure of kekulene's highest occupied molecular orbital by photoemission tomography. In agreement with a recent aromaticity assessment of kekulene based solely on C-C bond lengths, we conclude that the π-conjugation of kekulene is better described by the Clar model rather than a superaromatic model. Thus, by exploiting the capabilities of photoemission tomography, we shed light on the question which consequences aromaticity holds for the frontier electronic structure of a π-conjugated molecule.
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Affiliation(s)
- Anja Haags
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, 52074 Aachen, Germany
| | - Alexander Reichmann
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - Qitang Fan
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Larissa Egger
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - Hans Kirschner
- Physikalisch-Technische Bundesanstalt (PTB), 10587 Berlin, Germany
| | - Tim Naumann
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Simon Werner
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Tobias Vollgraff
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Jörg Sundermeyer
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Lukas Eschmann
- Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Xiaosheng Yang
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, 52074 Aachen, Germany
| | - Dominik Brandstetter
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - François C Bocquet
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - Georg Koller
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | | | - Mathias Richter
- Physikalisch-Technische Bundesanstalt (PTB), 10587 Berlin, Germany
| | - Michael G Ramsey
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - Michael Rohlfing
- Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Peter Puschnig
- Institut für Physik, Karl-Franzens-Universität Graz, NAWI Graz, 8010 Graz, Austria
| | - J Michael Gottfried
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Serguei Soubatch
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - F Stefan Tautz
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
- Experimentalphysik IV A, RWTH Aachen University, 52074 Aachen, Germany
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8
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Nuraliev MK, Parashchuk OD, Tukachev NV, Repeev YA, Maslennikov DR, Borshchev OV, Vainer YG, Paraschuk DY, Sosorev AY. Toward probing of the local electron–phonon interaction in small-molecule organic semiconductors with Raman spectroscopy. J Chem Phys 2020; 153:174303. [DOI: 10.1063/5.0023754] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Muzaffar K. Nuraliev
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory 1/62, Moscow 119991, Russia
| | - Olga D. Parashchuk
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory 1/62, Moscow 119991, Russia
| | - Nikita V. Tukachev
- Institute of Spectroscopy of the Russian Academy of Sciences, Fizicheskaya Str., 5, Troitsk, Moscow 108840, Russia
- Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Moscow 143026, Russia
| | - Yuri A. Repeev
- Institute of Spectroscopy of the Russian Academy of Sciences, Fizicheskaya Str., 5, Troitsk, Moscow 108840, Russia
| | - Dmitry R. Maslennikov
- Institute of Spectroscopy of the Russian Academy of Sciences, Fizicheskaya Str., 5, Troitsk, Moscow 108840, Russia
| | - Oleg V. Borshchev
- Enikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Science, Profsoyuznaya 70, Moscow 117393, Russia
| | - Yuri G. Vainer
- Institute of Spectroscopy of the Russian Academy of Sciences, Fizicheskaya Str., 5, Troitsk, Moscow 108840, Russia
| | - Dmitry Yu. Paraschuk
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory 1/62, Moscow 119991, Russia
| | - Andrey Yu. Sosorev
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory 1/62, Moscow 119991, Russia
- Institute of Spectroscopy of the Russian Academy of Sciences, Fizicheskaya Str., 5, Troitsk, Moscow 108840, Russia
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9
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Franco-Cañellas A, Duhm S, Gerlach A, Schreiber F. Binding and electronic level alignment of π-conjugated systems on metals. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2020; 83:066501. [PMID: 32101802 DOI: 10.1088/1361-6633/ab7a42] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We review the binding and energy level alignment of π-conjugated systems on metals, a field which during the last two decades has seen tremendous progress both in terms of experimental characterization as well as in the depth of theoretical understanding. Precise measurements of vertical adsorption distances and the electronic structure together with ab initio calculations have shown that most of the molecular systems have to be considered as intermediate cases between weak physisorption and strong chemisorption. In this regime, the subtle interplay of different effects such as covalent bonding, charge transfer, electrostatic and van der Waals interactions yields a complex situation with different adsorption mechanisms. In order to establish a better understanding of the binding and the electronic level alignment of π-conjugated molecules on metals, we provide an up-to-date overview of the literature, explain the fundamental concepts as well as the experimental techniques and discuss typical case studies. Thereby, we relate the geometric with the electronic structure in a consistent picture and cover the entire range from weak to strong coupling.
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Affiliation(s)
- Antoni Franco-Cañellas
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
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10
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Yamane H, Matsui F, Ueba T, Horigome T, Makita S, Tanaka K, Kera S, Kosugi N. Acceptance-cone-tunable electron spectrometer for highly-efficient constant energy mapping. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:093102. [PMID: 31575223 DOI: 10.1063/1.5109453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/12/2019] [Indexed: 06/10/2023]
Abstract
We have developed an acceptance-cone-tunable (ACT) electron spectrometer for the highly efficient constant-energy photoelectron mapping of functional materials. The ACT spectrometer consists of the hemispherical deflection analyzer with the mesh-type electrostatic lens near the sample. The photoelectron trajectory can be converged by applying a negative bias to the sample and grounding the mesh lens and the analyzer entrance. The performance of the present ACT spectrometer with neither rotating nor tilting of the sample is demonstrated by the wide-angle observation of the well-known π-band dispersion of a single crystalline graphite over the Brillouin zone. The acceptance cone of the spectrometer is expanded by a factor of 3.30 when the negative bias voltage is 10 times as high as the kinetic energy of photoelectrons.
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Affiliation(s)
- Hiroyuki Yamane
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Fumihiko Matsui
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Takahiro Ueba
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Toshio Horigome
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Seiji Makita
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Kiyohisa Tanaka
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Satoshi Kera
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Nobuhiro Kosugi
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
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11
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Mehler A, Néel N, Bocquet ML, Kröger J. Exciting vibrons in both frontier orbitals of a single hydrocarbon molecule on graphene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:065001. [PMID: 30523960 DOI: 10.1088/1361-648x/aaf54c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Vibronic excitations in molecules are key to the fundamental understanding of the interaction between vibrational and electronic degrees of freedom. In order to probe the genuine vibronic properties of a molecule even after its adsorption on a surface appropriate buffer layers are of paramount importance. Here, vibrational progression in both molecular frontier orbitals is observed with submolecular resolution on a graphene-covered metal surface using scanning tunnelling spectroscopy. Accompanying calculations demonstrate that the vibrational modes that cause the orbital replica in the progression share the same symmetry as the electronic states they couple to. In addition, the vibrational progression is more pronounced for separated molecules than for molecules embedded in molecular assemblies. The entire vibronic spectra of these molecular species are moreover rigidly shifted with respect to each other. This work unravels intramolecular changes in the vibronic and electronic structure owing to the efficient reduction of the molecule-metal hybridization by graphene.
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Affiliation(s)
- A Mehler
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
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12
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Multi-orbital charge transfer at highly oriented organic/metal interfaces. Nat Commun 2017; 8:335. [PMID: 28839127 PMCID: PMC5570996 DOI: 10.1038/s41467-017-00402-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/22/2017] [Indexed: 11/09/2022] Open
Abstract
The molecule-substrate interaction plays a key role in charge injection organic-based devices. Charge transfer at molecule-metal interfaces strongly affects the overall physical and magnetic properties of the system, and ultimately the device performance. Here, we report theoretical and experimental evidence of a pronounced charge transfer involving nickel tetraphenyl porphyrin molecules adsorbed on Cu(100). The exceptional charge transfer leads to filling of the higher unoccupied orbitals up to LUMO+3. As a consequence of this strong interaction with the substrate, the porphyrin's macrocycle sits very close to the surface, forcing the phenyl ligands to bend upwards. Due to this adsorption configuration, scanning tunneling microscopy cannot reliably probe the states related to the macrocycle. We demonstrate that photoemission tomography can instead access the Ni-TPP macrocycle electronic states and determine the reordering and filling of the LUMOs upon adsorption, thereby confirming the remarkable charge transfer predicted by density functional theory calculations.Charge transfer at molecule-metal interfaces affects the overall physical and magnetic properties of organic-based devices, and ultimately their performance. Here, the authors report evidence of a pronounced charge transfer involving nickel tetraphenyl porphyrin molecules adsorbed on copper.
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13
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Udhardt C, Otto F, Kern C, Lüftner D, Huempfner T, Kirchhuebel T, Sojka F, Meissner M, Schröter B, Forker R, Puschnig P, Fritz T. Influence of Film and Substrate Structure on Photoelectron Momentum Maps of Coronene Thin Films on Ag(111). THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:12285-12293. [PMID: 28620448 PMCID: PMC5467179 DOI: 10.1021/acs.jpcc.7b03500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Indexed: 05/17/2023]
Abstract
Angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) was measured for one-monolayer coronene films deposited on Ag(111). The (kx ,ky )-dependent photoelectron momentum maps (PMMs), which were extracted from the ARUPS data by cuts at fixed binding energies, show finely structured patterns for the highest and the second-highest occupied molecular orbitals. While the substructure of the PMM main features is related to the 4 × 4 commensurate film structure, various features with three-fold symmetry imply an additional influence of the substrate. PMM simulations on the basis of both free-standing coronene assemblies and coronene monolayers on the Ag(111) substrate confirm a sizable molecule-molecule interaction because no substructure was observed for PMM simulations using free coronene molecules.
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Affiliation(s)
- Christian Udhardt
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
| | - Felix Otto
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
| | - Christian Kern
- Institute
of Physics, University of Graz, NAWI-Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Daniel Lüftner
- Institute
of Physics, University of Graz, NAWI-Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Tobias Huempfner
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
| | - Tino Kirchhuebel
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
| | - Falko Sojka
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
| | - Matthias Meissner
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
| | - Bernd Schröter
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
| | - Roman Forker
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
| | - Peter Puschnig
- Institute
of Physics, University of Graz, NAWI-Graz, Universitätsplatz 5, 8010 Graz, Austria
| | - Torsten Fritz
- Institute
of Solid State Physics, Friedrich Schiller
University Jena, Helmholtzweg 5, 07743 Jena, Germany
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14
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Abstract
Organic (opto)electronic materials have received considerable attention due to their applications in thin-film-transistors, light-emitting diodes, solar cells, sensors, photorefractive devices, and many others. The technological promises include low cost of these materials and the possibility of their room-temperature deposition from solution on large-area and/or flexible substrates. The article reviews the current understanding of the physical mechanisms that determine the (opto)electronic properties of high-performance organic materials. The focus of the review is on photoinduced processes and on electronic properties important for optoelectronic applications relying on charge carrier photogeneration. Additionally, it highlights the capabilities of various experimental techniques for characterization of these materials, summarizes top-of-the-line device performance, and outlines recent trends in the further development of the field. The properties of materials based both on small molecules and on conjugated polymers are considered, and their applications in organic solar cells, photodetectors, and photorefractive devices are discussed.
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Affiliation(s)
- Oksana Ostroverkhova
- Department of Physics, Oregon State University , Corvallis, Oregon 97331, United States
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