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Strocov VN, Lev LL, Alarab F, Constantinou P, Wang X, Schmitt T, Stock TJZ, Nicolaï L, Očenášek J, Minár J. High-energy photoemission final states beyond the free-electron approximation. Nat Commun 2023; 14:4827. [PMID: 37563126 PMCID: PMC10415355 DOI: 10.1038/s41467-023-40432-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 07/26/2023] [Indexed: 08/12/2023] Open
Abstract
Three-dimensional (3D) electronic band structure is fundamental for understanding a vast diversity of physical phenomena in solid-state systems, including topological phases, interlayer interactions in van der Waals materials, dimensionality-driven phase transitions, etc. Interpretation of ARPES data in terms of 3D electron dispersions is commonly based on the free-electron approximation for the photoemission final states. Our soft-X-ray ARPES data on Ag metal reveals, however, that even at high excitation energies the final states can be a way more complex, incorporating several Bloch waves with different out-of-plane momenta. Such multiband final states manifest themselves as a complex structure and added broadening of the spectral peaks from 3D electron states. We analyse the origins of this phenomenon, and trace it to other materials such as Si and GaN. Our findings are essential for accurate determination of the 3D band structure over a wide range of materials and excitation energies in the ARPES experiment.
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Affiliation(s)
- V N Strocov
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland.
| | - L L Lev
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
- Moscow Institute of Physics and Technology, 141701, Dolgoprudny, Russia
| | - F Alarab
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - P Constantinou
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - X Wang
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - T Schmitt
- Swiss Light Source, Paul Scherrer Institute, 5232, Villigen-PSI, Switzerland
| | - T J Z Stock
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK
| | - L Nicolaï
- University of West Bohemia, New Technologies Research Centre, 301 00, Plzeň, Czech Republic
| | - J Očenášek
- University of West Bohemia, New Technologies Research Centre, 301 00, Plzeň, Czech Republic
| | - J Minár
- University of West Bohemia, New Technologies Research Centre, 301 00, Plzeň, Czech Republic.
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Krasovskii E. One-Step Theory View on Photoelectron Diffraction: Application to Graphene. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12224040. [PMID: 36432325 PMCID: PMC9698165 DOI: 10.3390/nano12224040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 05/27/2023]
Abstract
Diffraction of photoelectrons emitted from the core 1s and valence band of monolayer and bilayer graphene is studied within the one-step theory of photoemission. The energy-dependent angular distribution of the photoelectrons is compared to the simulated electron reflection pattern of a low-energy electron diffraction experiment in the kinetic energy range up to about 55 eV, and the implications for the structure determination are discussed. Constant energy contours due to scattering resonances are well visible in photoelectron diffraction, and their experimental shape is well reproduced. The example of the bilayer graphene is used to reveal the effect of the scattering by the subsurface layer. The photoemission and LEED patterns are shown to contain essentially the same information about the long-range order. The diffraction patterns of C 1s and valence band photoelectrons bear similar anisotropy and are equally suitable for diffraction analysis.
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Affiliation(s)
- Eugene Krasovskii
- Departamento de Polímeros y Materiales Avanzados, Física, Química y Tecnología, Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, 20080 Donostia/San Sebastián, Basque Country, Spain;
- Donostia International Physics Center (DIPC), 20018 Donostia/San Sebastián, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Basque Country, Spain
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Dávila ME, Ávila J, Colambo IR, Putungan DB, Woodruff DP, Asensio MC. New insight on the role of localisation in the electronic structure of the Si(111)(7 × 7) surfaces. Sci Rep 2021; 11:15034. [PMID: 34294856 PMCID: PMC8298386 DOI: 10.1038/s41598-021-94664-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/09/2021] [Indexed: 11/21/2022] Open
Abstract
New angle-resolved photoelectron spectroscopy (ARPES) data, recorded at several different photon energies from the Si(111)(7 × 7) surface, show that the well-known S1 and S2 surface states that lie in the bulk band gap are localised at specific (adatom and rest atom) sites on the reconstructed surface. The variations in the photoemission intensity from these states as a function of polar and azimuthal emission angle, and incident photon energy, are not consistent with Fermi surface mapping but are well-described by calculations of the multiple elastic scattering in the final state. This localisation of the most shallowly bound S1 state is consistent with the lack of significant dispersion, with no evidence of Fermi surface crossing, implying that the surface is not, as has been previously proposed, metallic in character. Our findings highlight the importance of final state scattering in interpreting ARPES data, an aspect that is routinely ignored and can lead to misleading conclusions.
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Affiliation(s)
- M E Dávila
- Materials Science Institute of Madrid (ICMM), Spanish Scientific Research Council (CSIC), 28049, Cantoblanco, Madrid, Spain
| | - J Ávila
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192, Gif sur Yvette Cedex, France
| | - I R Colambo
- Institute of Mathematical Sciences and Physics, University of the Philippines Los Baños, 4031, Los Baños, Laguna, Philippines
| | - D B Putungan
- Institute of Mathematical Sciences and Physics, University of the Philippines Los Baños, 4031, Los Baños, Laguna, Philippines
| | - D P Woodruff
- Physics Department, University of Warwick, Coventry, CV4 7AL, UK
| | - M C Asensio
- Materials Science Institute of Madrid (ICMM), Spanish Scientific Research Council (CSIC), 28049, Cantoblanco, Madrid, Spain.
- MATINEE: CSIC Research Associated Unit Between the Institute of Materials Science of the Valencia University (ICMUV) and the ICMM, 28049, Cantoblanco, Madrid, Spain.
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Medjanik K, Babenkov SV, Chernov S, Vasilyev D, Schönhense B, Schlueter C, Gloskovskii A, Matveyev Y, Drube W, Elmers HJ, Schönhense G. Progress in HAXPES performance combining full-field k-imaging with time-of-flight recording. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1996-2012. [PMID: 31721745 PMCID: PMC6853377 DOI: 10.1107/s1600577519012773] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/13/2019] [Indexed: 05/27/2023]
Abstract
An alternative approach to hard-X-ray photoelectron spectroscopy (HAXPES) has been established. The instrumental key feature is an increase of the dimensionality of the recording scheme from 2D to 3D. A high-energy momentum microscope detects electrons with initial kinetic energies up to 8 keV with a k-resolution of 0.025 Å-1, equivalent to an angular resolution of 0.034°. A special objective lens with k-space acceptance up to 25 Å-1 allows for simultaneous full-field imaging of many Brillouin zones. Combined with time-of-flight (ToF) parallel energy recording this yields maximum parallelization. Thanks to the high brilliance (1013 hν s-1 in a spot of <20 µm diameter) of beamline P22 at PETRA III (Hamburg, Germany), the microscope set a benchmark in HAXPES recording speed, i.e. several million counts per second for core-level signals and one million for d-bands of transition metals. The concept of tomographic k-space mapping established using soft X-rays works equally well in the hard X-ray range. Sharp valence band k-patterns of Re, collected at an excitation energy of 6 keV, correspond to direct transitions to the 28th repeated Brillouin zone. Measured total energy resolutions (photon bandwidth plus ToF-resolution) are 62 meV and 180 meV FWHM at 5.977 keV for monochromator crystals Si(333) and Si(311) and 450 meV at 4.0 keV for Si(111). Hard X-ray photoelectron diffraction (hXPD) patterns with rich fine structure are recorded within minutes. The short photoelectron wavelength (10% of the interatomic distance) `amplifies' phase differences, making full-field hXPD a sensitive structural tool.
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Affiliation(s)
- K. Medjanik
- Institut für Physik, Johannes Gutenberg Universität Mainz, D-55099 Mainz, Germany
| | - S. V. Babenkov
- Institut für Physik, Johannes Gutenberg Universität Mainz, D-55099 Mainz, Germany
| | - S. Chernov
- Institut für Physik, Johannes Gutenberg Universität Mainz, D-55099 Mainz, Germany
| | - D. Vasilyev
- Institut für Physik, Johannes Gutenberg Universität Mainz, D-55099 Mainz, Germany
| | - B. Schönhense
- Department of Bioengineering, Imperial College London, UK
| | - C. Schlueter
- DESY Photon Science, Notkestrasse 85, 22607 Hamburg, Germany
| | - A. Gloskovskii
- DESY Photon Science, Notkestrasse 85, 22607 Hamburg, Germany
| | - Yu. Matveyev
- DESY Photon Science, Notkestrasse 85, 22607 Hamburg, Germany
| | - W. Drube
- DESY Photon Science, Notkestrasse 85, 22607 Hamburg, Germany
| | - H. J. Elmers
- Institut für Physik, Johannes Gutenberg Universität Mainz, D-55099 Mainz, Germany
| | - G. Schönhense
- Institut für Physik, Johannes Gutenberg Universität Mainz, D-55099 Mainz, Germany
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Carbone F, Hengsberger M, Castiglioni L, Osterwalder J. Femtosecond manipulation of spins, charges, and ions in nanostructures, thin films, and surfaces. Struct Dyn 2017; 4:061504. [PMID: 29308416 PMCID: PMC5736395 DOI: 10.1063/1.4995541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/05/2017] [Indexed: 11/15/2022] Open
Affiliation(s)
- F. Carbone
- Ecole Polytechnique Fédérale de Lausanne, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES), EPFL Campus, Lausanne, Dorigny CH-1015, Switzerland
| | - M. Hengsberger
- Department of Physics, University of Zurich, CH-8057 Zurich, Switzerland
| | - L. Castiglioni
- Department of Physics, University of Zurich, CH-8057 Zurich, Switzerland
| | - J. Osterwalder
- Department of Physics, University of Zurich, CH-8057 Zurich, Switzerland
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Krüger P, Pieve FD. Gap state imaging and spin-orbit effects in resonant photoelectron diffraction. SURF INTERFACE ANAL 2016. [DOI: 10.1002/sia.6182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Peter Krüger
- Graduate School of Advanced Integration Science; Chiba University; Chiba 263-8522 Japan
| | - Fabiana Da Pieve
- Laboratoire des Solides Irradiés, UMR 7642, CNRS-CEA/DSM; École Polytechnique and European Theoretical Spectroscopy Facility (ETSF); Palaiseau F-91128 France
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Agarwal SK, Sodha MS. Analysis of Energy Distribution of Photoelectrons in Metals: Comparison with Experiment for Molybdenum. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES INDIA SECTION A-PHYSICAL SCIENCES 2014. [DOI: 10.1007/s40010-014-0168-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ziroff J, Forster F, Schöll A, Puschnig P, Reinert F. Hybridization of organic molecular orbitals with substrate states at interfaces: PTCDA on silver. PHYSICAL REVIEW LETTERS 2010; 104:233004. [PMID: 20867234 DOI: 10.1103/physrevlett.104.233004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Indexed: 05/28/2023]
Abstract
We demonstrate the application of orbital k-space tomography for the analysis of the bonding occurring at metal-organic interfaces. Using angle-resolved photoelectron spectroscopy, we probe the spatial structure of the highest occupied molecular orbital and the former lowest unoccupied molecular orbital (LUMO) of one monolayer 3, 4, 9, 10-perylene-tetracarboxylic-dianhydride (PTCDA) on Ag(110) and (111) surfaces and, in particular, the influence of the hybridization between the orbitals and the electronic states of the substrate. We are able to quantify and localize the substrate contribution to the LUMO and thus prove the metal-molecule hybrid character of this complex state.
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Affiliation(s)
- J Ziroff
- Universität Würzburg, Experimentelle Physik VII, 97074 Würzburg, Germany
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Kera S, Tanaka S, Yamane H, Yoshimura D, Okudaira K, Seki K, Ueno N. Quantitative analysis of photoelectron angular distribution of single-domain organic monolayer film: NTCDA on GeS(001). Chem Phys 2006. [DOI: 10.1016/j.chemphys.2005.10.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ni T, Nagesha DK, Robles J, Materer NF, Müssig S, Kotov NA. CdS nanoparticles modified to chalcogen sites: new supramolecular complexes, butterfly bridging, and related optical effects. J Am Chem Soc 2002; 124:3980-92. [PMID: 11942837 DOI: 10.1021/ja017149a] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
All present approaches to surface modification of nanoparticles (NPs) with organic ligands exploit metal (cadmium) sites as anchor points. To obtain efficient interaction of NP surface with p-orbitals of organic chromophores, we utilize the chalcogen (sulfur) sites on the NP surface. These sites present several advantages stemming from a stronger interaction of their atomic orbitals with both modifier and NP core. The chalcogen modification of CdS was achieved by using a mixed ligand (2,2'-bipyridyl-N,N')(malonato-O,O')-copper(II) monohydrate complex. The weak monodentate ligands (water) are replaced by a copper-sulfur bond during the modification reaction. The structure of the product was investigated by optical spectroscopy, electron spin resonance, and nuclear magnetic resonance. The modified NP can be described as a few tens (<40) of (2,2'-bipyridyl-N,N')(malonato-O,O')-copper units attached to the CdS core. Steady-state and time-resolved luminescence measurements, molecular orbital calculations, and UPS data indicate that delocalized surface states enveloping the surface chalcogen atoms of NP, transition metal, and p-orbitals of the bipyridine ligand are present in the synthesized species. The delocalized states are made possible due to the bridging of p-levels of sulfur and pi-orbitals of bipyridine by butterfly d-orbitals of the transition metal atom placed between them. Chalcogen-modified NP can be considered as a new member of the family of supramolecular compounds based on transition metal complexes. Both NP and metal complex parts of the prepared supramolecules are very versatile structural units, and new molecular constructs of similar design, in which quantum effects of NPs are combined with optical properties of transition metal complexes, can be obtained with different NPs and metal complexes.
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Affiliation(s)
- Tong Ni
- Chemistry Department, Oklahoma State University, Stillwater, Oklahoma 74078, USA
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