1
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Bugnet M, Löffler S, Ederer M, Kepaptsoglou DM, Ramasse QM. Current opinion on the prospect of mapping electronic orbitals in the transmission electron microscope: State of the art, challenges and perspectives. J Microsc 2024; 295:217-235. [PMID: 38818951 DOI: 10.1111/jmi.13321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/03/2024] [Accepted: 05/08/2024] [Indexed: 06/01/2024]
Abstract
The concept of electronic orbitals has enabled the understanding of a wide range of physical and chemical properties of solids through the definition of, for example, chemical bonding between atoms. In the transmission electron microscope, which is one of the most used and powerful analytical tools for high-spatial-resolution analysis of solids, the accessible quantity is the local distribution of electronic states. However, the interpretation of electronic state maps at atomic resolution in terms of electronic orbitals is far from obvious, not always possible, and often remains a major hurdle preventing a better understanding of the properties of the system of interest. In this review, the current state of the art of the experimental aspects for electronic state mapping and its interpretation as electronic orbitals is presented, considering approaches that rely on elastic and inelastic scattering, in real and reciprocal spaces. This work goes beyond resolving spectral variations between adjacent atomic columns, as it aims at providing deeper information about, for example, the spatial or momentum distributions of the states involved. The advantages and disadvantages of existing experimental approaches are discussed, while the challenges to overcome and future perspectives are explored in an effort to establish the current state of knowledge in this field. The aims of this review are also to foster the interest of the scientific community and to trigger a global effort to further enhance the current analytical capabilities of transmission electron microscopy for chemical bonding and electronic structure analysis.
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Affiliation(s)
- M Bugnet
- CNRS, INSA Lyon, Université Claude Bernard Lyon 1, MATEIS, UMR 5510, Villeurbanne, France
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury, UK
- School of Chemical and Process Engineering, University of Leeds, Leeds, UK
| | - S Löffler
- University Service Centre for Transmission Electron Microscopy, TU Wien, Wien, Austria
| | - M Ederer
- University Service Centre for Transmission Electron Microscopy, TU Wien, Wien, Austria
| | - D M Kepaptsoglou
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury, UK
- School of Physics, Engineering and Technology, University of York, York, UK
| | - Q M Ramasse
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury, UK
- School of Chemical and Process Engineering, University of Leeds, Leeds, UK
- School of Physics and Astronomy, University of Leeds, Leeds, UK
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2
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Bonnet N, Baaboura J, Castioni F, Woo SY, Ho CH, Watanabe K, Taniguchi T, Tizei LHG, Coenen T. Cathodoluminescence emission and electron energy loss absorption from a 2D transition metal dichalcogenide in van der Waals heterostructures. NANOTECHNOLOGY 2024; 35:405702. [PMID: 38604153 DOI: 10.1088/1361-6528/ad3d62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 04/11/2024] [Indexed: 04/13/2024]
Abstract
Nanoscale variations of optical properties in transition metal dichalcogenide (TMD) monolayers can be explored with cathodoluminescence (CL) and electron energy loss spectroscopy (EELS) using electron microscopes. To increase the CL emission intensity from TMD monolayers, the MoSe2flakes are encapsulated in hexagonal boron nitride (hBN), creating van der Waals (VdW) heterostructures. Until now, the studies have been exclusively focused on scanning transmission electron microscopy (STEM-CL) or scanning electron microscopy (SEM-CL), separately. Here, we present results, using both techniques on the same sample, thereby exploring a large acceleration voltage range. We correlate the CL measurements with STEM-EELS measurements acquired with different energy dispersions, to access both the low-loss region at ultra-high spectral resolution, and the core-loss region. This provides information about the weight of the various absorption phenomena including the direct TMD absorption, the hBN interband transitions, the hBN bulk plasmon, and the core losses of the atoms present in the heterostructure. The S(T)EM-CL measurements from the TMD monolayer only show emission from the A exciton. Combining the STEM-EELS and S(T)EM-CL measurements, we can reconstruct different decay pathways leading to the A exciton CL emission. The comparison with SEM-CL shows that this is also a good technique for TMD heterostructure characterization, where the reduced demands on sample preparation are appealing. To demonstrate the capabilities of SEM-CL imaging, we also measured on a SiO2/Si substrate, quintessential in the sample preparation of two-dimensional materials, which is electron-opaque and can only be measured in SEM-CL. The CL-emitting defects of SiO2make this substrate challenging to use, but we demonstrate that this background can be suppressed by using lower electron energy.
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Affiliation(s)
- Noémie Bonnet
- Delmic B.V., Kanaalweg 4, 2628 EB Delft, The Netherlands
| | - Jassem Baaboura
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, F-91405, Orsay, France
| | - Florian Castioni
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, F-91405, Orsay, France
| | - Steffi Y Woo
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, F-91405, Orsay, France
| | - Ching-Hwa Ho
- Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Luiz H G Tizei
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, F-91405, Orsay, France
| | - Toon Coenen
- Delmic B.V., Kanaalweg 4, 2628 EB Delft, The Netherlands
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3
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Angell DK, Li S, Utzat H, Thurston MLS, Liu Y, Dahl J, Carlson R, Shen ZX, Melosh N, Sinclair R, Dionne JA. Unraveling sources of emission heterogeneity in Silicon Vacancy color centers with cryo-cathodoluminescence microscopy. Proc Natl Acad Sci U S A 2024; 121:e2308247121. [PMID: 38551833 PMCID: PMC10998621 DOI: 10.1073/pnas.2308247121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 01/03/2024] [Indexed: 04/08/2024] Open
Abstract
Diamond color centers have proven to be versatile quantum emitters and exquisite sensors of stress, temperature, electric and magnetic fields, and biochemical processes. Among color centers, the silicon-vacancy (SiV[Formula: see text]) defect exhibits high brightness, minimal phonon coupling, narrow optical linewidths, and high degrees of photon indistinguishability. Yet the creation of reliable and scalable SiV[Formula: see text]-based color centers has been hampered by heterogeneous emission, theorized to originate from surface imperfections, crystal lattice strain, defect symmetry, or other lattice impurities. Here, we advance high-resolution cryo-electron microscopy combined with cathodoluminescence spectroscopy and 4D scanning transmission electron microscopy (STEM) to elucidate the structural sources of heterogeneity in SiV[Formula: see text] emission from nanodiamond with sub-nanometer-scale resolution. Our diamond nanoparticles are grown directly on TEM membranes from molecular-level seedings, representing the natural formation conditions of color centers in diamond. We show that individual subcrystallites within a single nanodiamond exhibit distinct zero-phonon line (ZPL) energies and differences in brightness that can vary by 0.1 meV in energy and over 70% in brightness. These changes are correlated with the atomic-scale lattice structure. We find that ZPL blue-shifts result from tensile strain, while ZPL red shifts are due to compressive strain. We also find that distinct crystallites host distinct densities of SiV[Formula: see text] emitters and that grain boundaries impact SiV[Formula: see text] emission significantly. Finally, we interrogate nanodiamonds as small as 40 nm in diameter and show that these diamonds exhibit no spatial change to their ZPL energy. Our work provides a foundation for atomic-scale structure-emission correlation, e.g., of single atomic defects in a range of quantum and two-dimensional materials.
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Affiliation(s)
- Daniel K. Angell
- Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Palo Alto, CA94305
| | - Shuo Li
- Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Palo Alto, CA94305
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA94025
| | - Hendrik Utzat
- Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Palo Alto, CA94305
| | - Matti L. S. Thurston
- Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Palo Alto, CA94305
| | - Yin Liu
- Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Palo Alto, CA94305
| | - Jeremy Dahl
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA94025
| | - Robert Carlson
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA94025
| | - Zhi-Xun Shen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA94025
- Department of Physics, Stanford University, Palo Alto, CA94305
- Department of Applied Physics, Stanford University, Palo Alto, CA94305
| | - Nicholas Melosh
- Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Palo Alto, CA94305
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA94025
| | - Robert Sinclair
- Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Palo Alto, CA94305
| | - Jennifer A. Dionne
- Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Palo Alto, CA94305
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4
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Dang Z, Chen Y, Fang Z. Cathodoluminescence Nanoscopy: State of the Art and Beyond. ACS NANO 2023; 17:24431-24448. [PMID: 38054434 DOI: 10.1021/acsnano.3c07593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Cathodoluminescence (CL) nanoscopy is proven to be a powerful tool to explore nanoscale optical properties, whereby free electron beams achieve a spatial resolution far beyond the diffraction limit of light. With developed methods for the control of electron beams and the collection of light, the dimension of information that CL can access has been expanded to include polarization, momentum, and time, holding promise to provide invaluable insights into the study of materials and optical near-field dynamics. With a focus on the burgeoning field of CL nanoscopy, this perspective outlines the recent advancements and applications of this technique, as illustrated by the salient experimental works. In addition, as an outlook for future research, several appealing directions that may bring about developments and discoveries are highlighted.
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Affiliation(s)
- Zhibo Dang
- School of Physics, State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, People's Republic of China
| | - Yuxiang Chen
- School of Physics, State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, People's Republic of China
| | - Zheyu Fang
- School of Physics, State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, People's Republic of China
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5
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Li X, Huang W, Krajnc A, Yang Y, Shukla A, Lee J, Ghasemi M, Martens I, Chan B, Appadoo D, Chen P, Wen X, Steele JA, Hackbarth HG, Sun Q, Mali G, Lin R, Bedford NM, Chen V, Cheetham AK, Tizei LHG, Collins SM, Wang L, Hou J. Interfacial alloying between lead halide perovskite crystals and hybrid glasses. Nat Commun 2023; 14:7612. [PMID: 37993424 PMCID: PMC10665442 DOI: 10.1038/s41467-023-43247-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 11/03/2023] [Indexed: 11/24/2023] Open
Abstract
The stellar optoelectronic properties of metal halide perovskites provide enormous promise for next-generation optical devices with excellent conversion efficiencies and lower manufacturing costs. However, there is a long-standing ambiguity as to whether the perovskite surface/interface (e.g. structure, charge transfer or source of off-target recombination) or bulk properties are the more determining factor in device performance. Here we fabricate an array of CsPbI3 crystal and hybrid glass composites by sintering and globally visualise the property-performance landscape. Our findings reveal that the interface is the primary determinant of the crystal phases, optoelectronic quality, and stability of CsPbI3. In particular, the presence of a diffusion "alloying" layer is discovered to be critical for passivating surface traps, and beneficially altering the energy landscape of crystal phases. However, high-temperature sintering results in the promotion of a non-stoichiometric perovskite and excess traps at the interface, despite the short-range structure of halide is retained within the alloying layer. By shedding light on functional hetero-interfaces, our research offers the key factors for engineering high-performance perovskite devices.
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Affiliation(s)
- Xuemei Li
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Wengang Huang
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Andraž Krajnc
- Department of Inorganic Chemistry and Technology, National Institute of Chemistry, 1001, Ljubljana, Slovenia
| | - Yuwei Yang
- School of Chemical Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Atul Shukla
- School of Mathematics and Physics, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Jaeho Lee
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Mehri Ghasemi
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
| | - Isaac Martens
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000, Grenoble, France
| | - Bun Chan
- Graduate School of Engineering, Nagasaki University, Nagasaki, 852-8521, Japan
| | - Dominique Appadoo
- Australian Synchrotron, 800 Blackburn Rd, Clayton, VIC, 3168, Australia
| | - Peng Chen
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Xiaoming Wen
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
| | - Julian A Steele
- School of Mathematics and Physics, The University of Queensland, St Lucia, QLD, 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Haira G Hackbarth
- School of Chemical Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Qiang Sun
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China
- Sichuan Provincial Engineering Research Center of Oral Biomaterials, Chengdu, Sichuan, 610041, China
| | - Gregor Mali
- Department of Inorganic Chemistry and Technology, National Institute of Chemistry, 1001, Ljubljana, Slovenia
| | - Rijia Lin
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Nicholas M Bedford
- School of Chemical Engineering, The University of New South Wales, Kensington, NSW, 2052, Australia
| | - Vicki Chen
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia
- University of Technology Sydney, 15 Broadway, Ultimo, NSW, 2007, Australia
| | - Anthony K Cheetham
- Materials Research Laboratory, University of California, Santa Barbara, CA, 93106, USA
| | - Luiz H G Tizei
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Sean M Collins
- School of Chemical and Process Engineering and School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK
| | - Lianzhou Wang
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Jingwei Hou
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia.
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6
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Moradifar P, Liu Y, Shi J, Siukola Thurston ML, Utzat H, van Driel TB, Lindenberg AM, Dionne JA. Accelerating Quantum Materials Development with Advances in Transmission Electron Microscopy. Chem Rev 2023. [PMID: 37979189 DOI: 10.1021/acs.chemrev.2c00917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2023]
Abstract
Quantum materials are driving a technology revolution in sensing, communication, and computing, while simultaneously testing many core theories of the past century. Materials such as topological insulators, complex oxides, superconductors, quantum dots, color center-hosting semiconductors, and other types of strongly correlated materials can exhibit exotic properties such as edge conductivity, multiferroicity, magnetoresistance, superconductivity, single photon emission, and optical-spin locking. These emergent properties arise and depend strongly on the material's detailed atomic-scale structure, including atomic defects, dopants, and lattice stacking. In this review, we describe how progress in the field of electron microscopy (EM), including in situ and in operando EM, can accelerate advances in quantum materials and quantum excitations. We begin by describing fundamental EM principles and operation modes. We then discuss various EM methods such as (i) EM spectroscopies, including electron energy loss spectroscopy (EELS), cathodoluminescence (CL), and electron energy gain spectroscopy (EEGS); (ii) four-dimensional scanning transmission electron microscopy (4D-STEM); (iii) dynamic and ultrafast EM (UEM); (iv) complementary ultrafast spectroscopies (UED, XFEL); and (v) atomic electron tomography (AET). We describe how these methods could inform structure-function relations in quantum materials down to the picometer scale and femtosecond time resolution, and how they enable precision positioning of atomic defects and high-resolution manipulation of quantum materials. For each method, we also describe existing limitations to solve open quantum mechanical questions, and how they might be addressed to accelerate progress. Among numerous notable results, our review highlights how EM is enabling identification of the 3D structure of quantum defects; measuring reversible and metastable dynamics of quantum excitations; mapping exciton states and single photon emission; measuring nanoscale thermal transport and coupled excitation dynamics; and measuring the internal electric field and charge density distribution of quantum heterointerfaces- all at the quantum materials' intrinsic atomic and near atomic-length scale. We conclude by describing open challenges for the future, including achieving stable sample holders for ultralow temperature (below 10K) atomic-scale spatial resolution, stable spectrometers that enable meV energy resolution, and high-resolution, dynamic mapping of magnetic and spin fields. With atomic manipulation and ultrafast characterization enabled by EM, quantum materials will be poised to integrate into many of the sustainable and energy-efficient technologies needed for the 21st century.
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Affiliation(s)
- Parivash Moradifar
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Yin Liu
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jiaojian Shi
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road MS69, Menlo Park, California 94025, United States
| | | | - Hendrik Utzat
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Tim B van Driel
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Aaron M Lindenberg
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road MS69, Menlo Park, California 94025, United States
| | - Jennifer A Dionne
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Department of Radiology, Stanford University, Stanford, California 94305, United States
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7
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Liu ACY, Davis TJ, Coenen T, Hari S, Voortman LM, Xu Z, Yuan G, Ballard PM, Funston AM, Etheridge J. Modulation of Cathodoluminescence by Surface Plasmons in Silver Nanowires. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2207747. [PMID: 37029699 DOI: 10.1002/smll.202207747] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 02/08/2023] [Indexed: 06/19/2023]
Abstract
The waveguide modes in chemically-grown silver nanowires on silicon nitride substrates are observed using spectrally- and spatially-resolved cathodoluminescence (CL) excited by high-energy electrons in a scanning electron microscope. The presence of a long-range, travelling surface plasmon mode modulates the coupling efficiency of the incident electron energy into the nanowires, which is observed as oscillations in the measured CL with the point of excitation by the focused electron beam. The experimental data are modeled using the theory of surface plasmon polariton modes in cylindrical metal waveguides, enabling the complex mode wavenumbers and excitation strength of the long-range surface plasmon mode to be extracted. The experiments yield insight into the energy transfer mechanisms between fast electrons and coherent oscillations in surface charge density in metal nanowires and the relative amplitudes of the radiative processes excited in the wire by the electron.
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Affiliation(s)
- Amelia C Y Liu
- School of Physics and Astronomy, Monash University, Clayton, Victoria, 3800, Australia
- Monash Centre for Electron Microscopy, Monash University, Clayton, Victoria, 3800, Australia
| | - Timothy J Davis
- School of Physics, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Toon Coenen
- Delmic BV, Kanaalweg 4, Delft, 2628 EB, The Netherlands
| | | | - Lenard M Voortman
- Delmic BV, Kanaalweg 4, Delft, 2628 EB, The Netherlands
- Division of Cell and Chemical Biology, Leiden University Medical Centre, Leiden University, Leiden, 2333 ZC, The Netherlands
| | - Zhou Xu
- Monash Centre for Electron Microscopy, Monash University, Clayton, Victoria, 3800, Australia
| | - Gangcheng Yuan
- ARC Centre of Excellence in Exciton Science and School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia
| | - Patrycja M Ballard
- ARC Centre of Excellence in Exciton Science and School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia
| | - Alison M Funston
- ARC Centre of Excellence in Exciton Science and School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia
| | - Joanne Etheridge
- School of Physics and Astronomy, Monash University, Clayton, Victoria, 3800, Australia
- Monash Centre for Electron Microscopy, Monash University, Clayton, Victoria, 3800, Australia
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, 3800, Australia
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8
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Alem N, Bachu S, Woo SY, Miao L, Huet B, Redwing JM, Kociak M, Tizei LHG. Determination of Local Electronic Structure and Optical Response Using Spectroscopy Methods in STEM Assisted by Unsupervised Machine Learning. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:390-391. [PMID: 37613627 DOI: 10.1093/micmic/ozad067.183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Nasim Alem
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Saiphaneendra Bachu
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Steffi Y Woo
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS-UMR 8502, Orsay, France
| | - Leixin Miao
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Benjamin Huet
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Joan M Redwing
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - Mathieu Kociak
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS-UMR 8502, Orsay, France
| | - Luiz H G Tizei
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS-UMR 8502, Orsay, France
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9
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Adachi Y, Yamamoto N, Sannomiya T. Focused light introduction into transmission electron microscope via parabolic mirror. Ultramicroscopy 2023; 251:113759. [PMID: 37245285 DOI: 10.1016/j.ultramic.2023.113759] [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: 11/30/2022] [Revised: 04/26/2023] [Accepted: 05/13/2023] [Indexed: 05/30/2023]
Abstract
We developed a novel light optics system installed in a scanning transmission electron microscope (STEM) to introduce a focused light accurately adjusted at the electron beam irradiation position using a parabolic mirror. With a parabolic mirror covering both the upper and lower sides of the sample, the position and focus of the light beam can be evaluated by imaging the angular distribution of the transmitted light. By comparing the light image and the electron micrograph, the irradiation positions of the electron beam and the laser beam can be accurately adjusted to each other. The size of the focused light was confirmed to be within a few microns from the light Ronchigram, which is consistent with the simulated light spot size. The spot size and position alignment were further confirmed by laser-ablating only a targeted polystyrene particle without damaging the surrounding particles. When using a halogen lamp as the light source, this system allows investigating optical spectra in comparison with cathodoluminescence (CL) spectra at exactly the same location.
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Affiliation(s)
- Yoshikazu Adachi
- School of Materials and Chemical Technology, Department of Materials Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midoriku, Yokohama 226-8503, Japan
| | - Naoki Yamamoto
- School of Materials and Chemical Technology, Department of Materials Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midoriku, Yokohama 226-8503, Japan
| | - Takumi Sannomiya
- School of Materials and Chemical Technology, Department of Materials Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midoriku, Yokohama 226-8503, Japan.
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10
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Machfuudzoh I, Hinamoto T, García de Abajo FJ, Sugimoto H, Fujii M, Sannomiya T. Visualizing the Nanoscopic Field Distribution of Whispering-Gallery Modes in a Dielectric Sphere by Cathodoluminescence. ACS PHOTONICS 2023; 10:1434-1445. [PMID: 37215315 PMCID: PMC10197164 DOI: 10.1021/acsphotonics.3c00041] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Indexed: 05/24/2023]
Abstract
A spherical dielectric particle can sustain the so-called whispering-gallery modes (WGMs), which can be regarded as circulating electromagnetic waves, resulting in the spatial confinement of light inside the particle. Despite the wide adoption of optical WGMs as a major light confinement mechanism in salient practical applications, direct imaging of the mode fields is still lacking and only partially addressed by simple photography and simulation work. The present study comprehensively covers this research gap by demonstrating the nanoscale optical-field visualization of self-interference of light extracted from excited modes through experimentally obtained photon maps that directly portray the field distributions of the excited eigenmodes. To selectively choose the specific modes at a given light emission detection angle and resonance wavelength, we use cathodoluminescence-based scanning transmission electron microscopy supplemented with angle-, polarization-, and wavelength-resolved capabilities. Equipped with semi-analytical simulation tools, the internal field distributions of the whispering-gallery modes reveal that radiation emitted by a spherical resonator at a given resonance frequency is composed of the interference between multiple modes, with one or more of them being comparatively dominant, leading to a resulting distribution featuring complex patterns that explicitly depend on the detection angle and polarization. Direct visualization of the internal fields inside resonators enables a comprehensive understanding of WGMs that can shed light on the design of nanophotonic applications.
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Affiliation(s)
- Izzah Machfuudzoh
- Department
of Materials Science and Engineering, School of Materials and Chemical
Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 Japan
| | - Tatsuki Hinamoto
- Department
of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan
| | - F. Javier García de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució
Catalana de Recerca i Estudis Avancats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Hiroshi Sugimoto
- Department
of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan
| | - Minoru Fujii
- Department
of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan
| | - Takumi Sannomiya
- Department
of Materials Science and Engineering, School of Materials and Chemical
Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 Japan
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11
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Gonçalves PAD, García de Abajo FJ. Interrogating Quantum Nonlocal Effects in Nanoplasmonics through Electron-Beam Spectroscopy. NANO LETTERS 2023; 23:4242-4249. [PMID: 37172322 DOI: 10.1021/acs.nanolett.3c00298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A rigorous account of quantum nonlocal effects is paramount for understanding the optical response of metal nanostructures and for designing plasmonic devices at the nanoscale. Here, we present a scheme for retrieving the quantum surface response of metals, encapsulated in the Feibelman d-parameters, from electron energy-loss spectroscopy (EELS) and cathodoluminescence (CL) measurements. We theoretically demonstrate that quantum nonlocal effects have a dramatic impact on EELS and CL spectra, in the guise of spectral shifts and nonlocal damping, when either the system size or the inverse wave vector in extended structures approaches the nanometer scale. Our concept capitalizes on the unparalleled ability of free electrons to supply deeply subwavelength near-fields and, thus, probe the optical response of metals at length scales in which quantum-mechanical effects are apparent. These results pave the way for a widespread use of the d-parameter formalism, thereby facilitating a rigorous yet practical inclusion of nonclassical effects in nanoplasmonics.
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Affiliation(s)
- P A D Gonçalves
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860Castelldefels, Barcelona, Spain
| | - F Javier García de Abajo
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860Castelldefels, Barcelona, Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
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12
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Alprol AE, Mansour AT, El-Beltagi HS, Ashour M. Algal Extracts for Green Synthesis of Zinc Oxide Nanoparticles: Promising Approach for Algae Bioremediation. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16072819. [PMID: 37049112 PMCID: PMC10096179 DOI: 10.3390/ma16072819] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/24/2023] [Accepted: 03/30/2023] [Indexed: 05/31/2023]
Abstract
Zinc oxide nanoparticles (ZnO-NPs) possess unique properties, making them a popular material across various industries. However, traditional methods of synthesizing ZnO-NPs are associated with environmental and health risks due to the use of harmful chemicals. As a result, the development of eco-friendly manufacturing practices, such as green-synthesis methodologies, has gained momentum. Green synthesis of ZnO-NPs using biological substrates offers several advantages over conventional approaches, such as cost-effectiveness, simplicity of scaling up, and reduced environmental impact. While both dried dead and living biomasses can be used for synthesis, the extracellular mode is more commonly employed. Although several biological substrates have been successfully utilized for the green production of ZnO-NPs, large-scale production remains challenging due to the complexity of biological extracts. In addition, ZnO-NPs have significant potential for photocatalysis and adsorption in the remediation of industrial effluents. The ease of use, efficacy, quick oxidation, cost-effectiveness, and reduced synthesis of harmful byproducts make them a promising tool in this field. This review aims to describe the different biological substrate sources and technologies used in the green synthesis of ZnO-NPs and their impact on properties. Traditional synthesis methods using harmful chemicals limit their clinical field of use. However, the emergence of algae as a promising substrate for creating safe, biocompatible, non-toxic, economic, and ecological synthesis techniques is gaining momentum. Future research is required to explore the potential of other algae species for biogenic synthesis. Moreover, this review focuses on how green synthesis of ZnO-NPs using biological substrates offers a viable alternative to traditional methods. Moreover, the use of these nanoparticles for industrial-effluent remediation is a promising field for future research.
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Affiliation(s)
- Ahmed E. Alprol
- National Institute of Oceanography and Fisheries (NIOF), Cairo 11516, Egypt
| | - Abdallah Tageldein Mansour
- Animal and Fish Production Department, College of Agricultural and Food Sciences, King Faisal University, P.O. Box 420, Al Hofuf 31982, Saudi Arabia
- Fish and Animal Production Department, Faculty of Agriculture (Saba Basha), Alexandria University, Alexandria 21531, Egypt
| | - Hossam S. El-Beltagi
- Agricultural Biotechnology Department, College of Agriculture and Food Sciences, King Faisal University, P.O. Box 420, Al-Ahsa 31982, Saudi Arabia
- Biochemistry Department, Faculty of Agriculture, Cairo University, Giza 12613, Egypt
| | - Mohamed Ashour
- National Institute of Oceanography and Fisheries (NIOF), Cairo 11516, Egypt
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13
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Torabi A, Sullivan J, Reich C, Wunch MA, Garcia JA, Beck C, Munshi AH, Shimpi T, Roberts M, Sampath W, Harvey TB. Quantitative Cathodoluminescence Mapping: A CdMgSeTe Thin-Film Case Study. ACS OMEGA 2022; 7:36873-36879. [PMID: 36278043 PMCID: PMC9583303 DOI: 10.1021/acsomega.2c05640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Full-spectrum cathodoluminescence (CL) mapping provides a point-by-point spatial measurement of the apparent band gap of a semiconductor thin film. In most studies, analysis of the electrical film properties from CL is presented as color mapping images. We have developed a spectra data analysis algorithm to functionalize, analyze, and generate statistical measurements of the luminescence data to provide additional insights. This algorithm was coded in the R language program, and a set of CdMgSeTe films were studied as an application case study. CL maps were measured for samples with different luminescent responses. A quantitative measure of the heterogeneity of the films was generated by statistical analysis of luminescent intensity and wavelength, spectra type curves, frequency distributions of peak wavelength, and relative intensity maps. The final CL analysis facilitates the investigation of the CdMgSeTe films and has potential applications for many semiconductor films.
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Affiliation(s)
- Aida Torabi
- Department
of Science and Mathematics, Texas A&M
University-Central Texas, Killeen, Texas 76549, United States
| | - James Sullivan
- Department
of Science and Mathematics, Texas A&M
University-Central Texas, Killeen, Texas 76549, United States
| | - Carey Reich
- Department
of Mechanical Engineering, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Melissa A. Wunch
- Department
of Science and Mathematics, Texas A&M
University-Central Texas, Killeen, Texas 76549, United States
| | - Juan Alexandro Garcia
- Department
of Science and Mathematics, Texas A&M
University-Central Texas, Killeen, Texas 76549, United States
| | - Claudia Beck
- Department
of Science and Mathematics, Texas A&M
University-Central Texas, Killeen, Texas 76549, United States
| | - Amit H. Munshi
- Department
of Mechanical Engineering, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Tushar Shimpi
- Department
of Mechanical Engineering, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Mienie Roberts
- Department
of Science and Mathematics, Texas A&M
University-Central Texas, Killeen, Texas 76549, United States
| | - Walajabad Sampath
- Department
of Mechanical Engineering, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Taylor B. Harvey
- Department
of Science and Mathematics, Texas A&M
University-Central Texas, Killeen, Texas 76549, United States
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14
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Varkentina N, Auad Y, Woo SY, Zobelli A, Bocher L, Blazit JD, Li X, Tencé M, Watanabe K, Taniguchi T, Stéphan O, Kociak M, Tizei LHG. Cathodoluminescence excitation spectroscopy: Nanoscale imaging of excitation pathways. SCIENCE ADVANCES 2022; 8:eabq4947. [PMID: 36206335 PMCID: PMC9544325 DOI: 10.1126/sciadv.abq4947] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 08/23/2022] [Indexed: 06/16/2023]
Abstract
Following optical excitations' life span from creation to decay into photons is crucial in understanding materials photophysics. Macroscopically, this is studied using optical techniques, such as photoluminescence excitation spectroscopy. However, excitation and emission pathways can vary at nanometer scales, preventing direct access, as no characterization technique has the relevant spatial, spectral, and time resolution. Here, using combined electron spectroscopies, we explore excitations' creation and decay in two representative optical materials: plasmonic nanoparticles and luminescent two-dimensional layers. The analysis of the energy lost by an exciting electron that is coincident in time with a visible-ultraviolet photon unveils the decay pathways from excitation toward light emission. This is demonstrated for phase-locked (coherent) interactions (localized surface plasmons) and non-phase-locked ones (point defect excited states). The developed cathodoluminescence excitation spectroscopy images energy transfer pathways at the nanometer scale, widening the available toolset to explore nanoscale materials.
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Affiliation(s)
- Nadezda Varkentina
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Yves Auad
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Steffi Y. Woo
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Alberto Zobelli
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Laura Bocher
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Jean-Denis Blazit
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Xiaoyan Li
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Marcel Tencé
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Odile Stéphan
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Mathieu Kociak
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
| | - Luiz H. G. Tizei
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay 91405, France
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15
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Discrimination of coherent and incoherent cathodoluminescence using temporal photon correlations. Ultramicroscopy 2022; 241:113594. [DOI: 10.1016/j.ultramic.2022.113594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 07/12/2022] [Accepted: 07/21/2022] [Indexed: 11/17/2022]
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16
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Zaluzec NJ. X-ray Spectrometry in the Era of Aberration-Corrected Electron Optical Beam Lines. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 29:1-7. [PMID: 35535554 DOI: 10.1017/s143192762200068x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Aberration correction in the analytical transmission electron microscope is most closely associated with improvements in high-resolution imaging. In this paper, the combination of that technology with new system designs, which optimize both electron optics and x-ray detection, is shown to provide more than a tenfold increase in performance over the last 25 years.
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Affiliation(s)
- Nestor J Zaluzec
- Photon Sciences Directorate, Argonne National Laboratory, Lemont, IL, USA
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17
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Johnson CW, Turner AE, García de Abajo FJ, McMorran BJ. Inelastic Mach-Zehnder Interferometry with Free Electrons. PHYSICAL REVIEW LETTERS 2022; 128:147401. [PMID: 35476465 DOI: 10.1103/physrevlett.128.147401] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 03/09/2022] [Indexed: 05/27/2023]
Abstract
We use a novel scanning electron Mach-Zehnder interferometer constructed in a conventional transmission electron microscope to perform inelastic interferometric imaging with free electrons. An electron wave function is prepared in two paths that pass on opposite sides of a gold nanoparticle, where plasmons are excited before the paths are recombined to produce electron interference. We show that the measured spectra are consistent with theoretical predictions, specifically that the interference signal formed by inelastically scattered electrons is π out of phase with respect to that formed by elastically scattered electrons. This technique is sensitive to the phase of localized optical modes, because the interference signal amounts to a substantial fraction of the transmitted electrons. Thus, we argue that inelastic interferometric imaging with our scanning electron Mach-Zehnder interferometer provides a new platform for controlling the transverse momentum of free electrons and studying coherent electron-matter interactions at the nanoscale.
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Affiliation(s)
- Cameron W Johnson
- Department of Physics, University of Oregon, Eugene, Oregon 97403, USA
| | - Amy E Turner
- Department of Physics, University of Oregon, Eugene, Oregon 97403, USA
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
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18
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Peña Román RJ, Auad Y, Grasso L, Padilha LA, Alvarez F, Barcelos ID, Kociak M, Zagonel LF. Design and implementation of a device based on an off-axis parabolic mirror to perform luminescence experiments in a scanning tunneling microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:043704. [PMID: 35489916 DOI: 10.1063/5.0078423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/27/2022] [Indexed: 06/14/2023]
Abstract
We present the design, implementation, and illustrative results of a light collection/injection strategy based on an off-axis parabolic mirror collector for a low-temperature Scanning Tunneling Microscope (STM). This device allows us to perform STM induced Light Emission (STM-LE) and Cathodoluminescence (STM-CL) experiments and in situ Photoluminescence (PL) and Raman spectroscopy as complementary techniques. Considering the Étendue conservation and using an off-axis parabolic mirror, it is possible to design a light collection and injection system that displays 72% of collection efficiency (considering the hemisphere above the sample surface) while maintaining high spectral resolution and minimizing signal loss. The performance of the STM is tested by atomically resolved images and scanning tunneling spectroscopy results on standard sample surfaces. The capabilities of our system are demonstrated by performing STM-LE on metallic surfaces and two-dimensional semiconducting samples, observing both plasmonic and excitonic emissions. In addition, we carried out in situ PL measurements on semiconducting monolayers and quantum dots and in situ Raman on graphite and hexagonal boron nitride (h-BN) samples. Additionally, STM-CL and PL were obtained on monolayer h-BN gathering luminescence spectra that are typically associated with intragap states related to carbon defects. The results show that the flexible and efficient light injection and collection device based on an off-axis parabolic mirror is a powerful tool to study several types of nanostructures with multiple spectroscopic techniques in correlation with their morphology at the atomic scale and electronic structure.
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Affiliation(s)
- Ricardo Javier Peña Román
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Yves Auad
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Lucas Grasso
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Lazaro A Padilha
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Fernando Alvarez
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Ingrid David Barcelos
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-970 Campinas, SP, Brazil
| | - Mathieu Kociak
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Luiz Fernando Zagonel
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
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19
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Guo A, He B, Li A, Jiang H. In vitro and in vivo characterization of insulin vesicles by electron microscopy. Biochem Biophys Res Commun 2022; 597:23-29. [PMID: 35123262 DOI: 10.1016/j.bbrc.2022.01.104] [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: 01/18/2022] [Accepted: 01/26/2022] [Indexed: 11/28/2022]
Abstract
Insulin is the main hypoglycemic hormone, promoting the absorption and storage of glucose and inhibiting its production. It is a hexamer composed of six insulin macromolecules and a Zn2+ and clustered in insulin vesicles of pancreatic β cell. Most current research has focused on the in vivo imaging of whole cells while there are few detailed studies on structure of insulin vesicles. The precise content of Zn2+ in vesicles is not clear, and the aggregation state and location of insulin in insulin vesicles is not fully characterized, which hinders a thorough understanding of insulin secretion process and diseases caused by blood sugar regulation. Here, we performed electron microscopy (EM) studies on both whole cells (in vivo) and extracted isolated insulin vesicles by supercentrifugation (in vitro) to explore the location and distribution of insulin vesicles in pancreatic β cells. Meanwhile, we analyzed the content of Zn2+ and Ca2+ through EM imaging and energy dispersive spectroscopy (EDS) mapping, and the content of Zn2+ was found to be proportional to the size of insulin vesicles. In addition, by taking advantage of TEM tomography, the three-dimensional structure of insulin vesicle was obtained by acquisition projections in different angles of insulin vesicle. This study provides a promising way to quantitative analysis of intracellular insulin, which may be of great significance to the study of diabetes and other blood sugar diseases.
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Affiliation(s)
- Amin Guo
- School of Physical Science and Technology, & Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
| | - Bo He
- School of Physical Science and Technology, & Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
| | - Angdi Li
- iHuman Institute, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Huaidong Jiang
- School of Physical Science and Technology, & Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China.
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20
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Auad Y, Hamon C, Tencé M, Lourenço-Martins H, Mkhitaryan V, Stéphan O, García de Abajo FJ, Tizei LHG, Kociak M. Unveiling the Coupling of Single Metallic Nanoparticles to Whispering-Gallery Microcavities. NANO LETTERS 2022; 22:319-327. [PMID: 34907775 DOI: 10.1021/acs.nanolett.1c03826] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Whispering-gallery mode resonators host multiple trapped narrow-band circulating optical resonances that find applications in quantum electrodynamics, optomechanics, and sensing. However, the spherical symmetry and low field leakage of dielectric microspheres make it difficult to probe their high-quality optical modes using far-field radiation. Even so, local field enhancement from metallic nanoparticles (MNPs) coupled to the resonators can interface the optical far field and the bounded cavity modes. In this work, we study the interaction between whispering-gallery modes and MNP surface plasmons with nanometric spatial resolution by using electron-beam spectroscopy with a scanning transmission electron microscope. We show that gallery modes are induced over a selective spectral range of the nanoparticle plasmons, and additionally, their polarization can be controlled by the induced dipole moment of the MNP. Our study demonstrates a viable mechanism to effectively excite high-quality-factor whispering-gallery modes and holds potential for applications in optical sensing and light manipulation.
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Affiliation(s)
- Yves Auad
- Laboratoire des Physique des Solides, Université Paris Saclay, CNRS, 91405 Orsay, France
| | - Cyrille Hamon
- Laboratoire des Physique des Solides, Université Paris Saclay, CNRS, 91405 Orsay, France
| | - Marcel Tencé
- Laboratoire des Physique des Solides, Université Paris Saclay, CNRS, 91405 Orsay, France
| | - Hugo Lourenço-Martins
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
- IV. Physical Institute, University of Göttingen, 37077 Göttingen, Germany
| | - Vahagn Mkhitaryan
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Odile Stéphan
- Laboratoire des Physique des Solides, Université Paris Saclay, CNRS, 91405 Orsay, France
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Luiz H G Tizei
- Laboratoire des Physique des Solides, Université Paris Saclay, CNRS, 91405 Orsay, France
| | - Mathieu Kociak
- Laboratoire des Physique des Solides, Université Paris Saclay, CNRS, 91405 Orsay, France
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21
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Abstract
Implementing the modern technologies of light-emitting devices, light harvesting, and quantum information processing requires the understanding of the structure-function relations at spatial scales below the optical diffraction limit and time scales of energy and information flows. Here, we distinctively combine cathodoluminescence (CL) with ultrafast electron microscopy (UEM), termed CL-UEM, because CL and UEM synergetically afford the required spectral and spatiotemporal sensitivities, respectively. For color centers in nanodiamonds, we demonstrate the measurement of CL lifetime with a local sensitivity of 50 nm and a time resolution of 100 ps. It is revealed that the emitting states of the color centers can be populated through charge transfer among the color centers across diamond lattices upon high-energy electron beam excitation. The technical advance achieved in this study will facilitate the specific control over energy conversion at nanoscales, relevant to quantum dots and single-photon sources.
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Affiliation(s)
- Ye-Jin Kim
- Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
- Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 44919, Korea
| | - Oh-Hoon Kwon
- Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Korea
- Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 44919, Korea
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22
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Bittorf PH, Davoodi F, Taleb M, Talebi N. Mapping optical Bloch modes of a plasmonic square lattice in real and reciprocal spaces using cathodoluminescence spectroscopy. OPTICS EXPRESS 2021; 29:34328-34340. [PMID: 34809226 DOI: 10.1364/oe.437984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Strong electron-light interactions supported by the surface plasmon polaritons excited in metallic thin films can lead to faster optoelectronic devices. Merging surface polaritons with photonic crystals leads to the formation of Bloch plasmons, allowing for the molding of the flow of polaritons and the controlling of the optical density of states for even stronger electron-light interactions. Here, we use a two-dimensional square lattice of holes incorporated inside a plasmonic gold layer to investigate the interaction of surface plasmon polaritons with the square lattice and the formation of plasmonic Bloch modes. Cathodoluminescence spectroscopy and hyperspectral imaging are used for imaging the spatio-spectral near-field distribution of the optical Bloch modes in the visible to near infrared spectral ranges. In addition, the higher-order Brillouin zones of the plasmonic lattice are demonstrated by using angle-resolved cathodoluminescence mapping. We further complement our experimental results with numerical simulations of the optical modes supported by the plasmonic lattice that helps to better resolve the superposition of the various modes excited by the electron beam. Next to previous works in this context, our results thus place cathodoluminescence scanning spectroscopy and angle-resolved mapping as complementary techniques to uncover the spatio-spectral distribution of optical Bloch modes in real and reciprocal spaces.
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23
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Żak AM, Kaczmarczyk O, Piksa M, Grzęda J, Matczyszyn K. Fiber-optic sample illuminator design for the observation of light induced phenomena with transmission electron microscopy in situ: Antimicrobial photodynamic therapy. Ultramicroscopy 2021; 230:113388. [PMID: 34509894 DOI: 10.1016/j.ultramic.2021.113388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/25/2021] [Accepted: 08/30/2021] [Indexed: 10/20/2022]
Abstract
Antibacterial photodynamic therapy is a promising treatment for problematic infections caused by bacteria and fungi. Despite its undoubted effectiveness, the ultrastructural mechanism of microbial death remains not fully described and distinct organisms respond to the treatment with different efficacy. For this reason, it was decided to try imaging the process using the in situ transmission electron microscopy method. To conduct an observational experiment, the microscope was significantly modified. Liquid cell methods were used, electron doses and their influence on the sample were estimated, and a fiber-optic sample illuminator was designed and built. The modifications allowed for the light-induced characterization of photosensitizer-bacteria interaction. Microscope modification is a promising platform for further studies of light-induced phenomena in both life and material science.
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Affiliation(s)
- Andrzej M Żak
- Electron Microscopy Laboratory, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Rudolfa Weigla 12, 53-114 Wroclaw, Poland.
| | - Olga Kaczmarczyk
- Electron Microscopy Laboratory, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Marta Piksa
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Rudolfa Weigla 12, 53-114 Wroclaw, Poland
| | - Jakub Grzęda
- Department of Lightweight Elements Engineering, Foundry and Automation, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Katarzyna Matczyszyn
- Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
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Ruimy R, Gorlach A, Mechel C, Rivera N, Kaminer I. Toward Atomic-Resolution Quantum Measurements with Coherently Shaped Free Electrons. PHYSICAL REVIEW LETTERS 2021; 126:233403. [PMID: 34170167 DOI: 10.1103/physrevlett.126.233403] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 03/30/2021] [Indexed: 05/27/2023]
Abstract
Free electrons provide a powerful tool for probing material properties at atomic resolution. Recent advances in ultrafast electron microscopy enable the manipulation of free-electron wave functions using laser pulses. It would be of great importance if one could combine the spatial resolution of electron microscopes with the ability of laser pulses to probe coherent phenomena in quantum systems. To this end, we propose a novel concept that leverages free electrons that are coherently shaped by laser pulses to measure quantum coherence in materials. We develop the quantum theory of interactions between shaped electrons and arbitrary qubit states in materials, and show how the postinteraction electron energy spectrum enables measuring the qubit state (on the Bloch sphere) and the decoherence or relaxation times (T_{2}/T_{1}). Finally, we describe how such electrons can detect and quantify superradiance from multiple qubits. Our scheme can be implemented in ultrafast transmission electron microscopes (UTEM), opening the way toward the full characterization of the state of quantum systems at atomic resolution.
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Affiliation(s)
- Ron Ruimy
- Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Alexey Gorlach
- Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Chen Mechel
- Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Nicholas Rivera
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Ido Kaminer
- Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
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25
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Sutter P, French JS, Khosravi Khorashad L, Argyropoulos C, Sutter E. Optoelectronics and Nanophotonics of Vapor-Liquid-Solid Grown GaSe van der Waals Nanoribbons. NANO LETTERS 2021; 21:4335-4342. [PMID: 33955765 DOI: 10.1021/acs.nanolett.1c00891] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
2D/layered semiconductors are of interest for fundamental studies and for applications in optoelectronics and photonics. Work to date focused on extended crystals, produced by exfoliation or growth and investigated by diffraction-limited spectroscopy. Processes such as vapor-liquid-solid (VLS) growth carry potential for mass-producing nanostructured van der Waals semiconductors with exceptionally high crystal quality and optoelectronic/photonic properties at least on par with those of extended flakes. Here, we demonstrate the synthesis, structure, morphology, and optoelectronics/photonics of GaSe van der Waals nanoribbons obtained by Au- and Ag-catalyzed VLS growth. Although all GaSe ribbons are high-quality basal-plane oriented single crystals, those grown at lower temperatures stand out with their remarkably uniform morphology and low edge roughness. Photoluminescence spectroscopy shows intense, narrow light emission at the GaSe bandgap energy. Nanophotonic experiments demonstrate traveling waveguide modes at visible/near-infrared energies and illustrate approaches for locally exciting and probing such photonic modes by cathodoluminescence in transmission electron microscopy.
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Affiliation(s)
- Peter Sutter
- Department of Electrical & Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Jacob S French
- Department of Electrical & Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Larousse Khosravi Khorashad
- Department of Electrical & Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Christos Argyropoulos
- Department of Electrical & Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Eli Sutter
- Department of Mechanical & Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
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26
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Schmidt FP, Losquin A, Horák M, Hohenester U, Stöger-Pollach M, Krenn JR. Fundamental Limit of Plasmonic Cathodoluminescence. NANO LETTERS 2021; 21:590-596. [PMID: 33336569 PMCID: PMC7809694 DOI: 10.1021/acs.nanolett.0c04084] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/27/2020] [Indexed: 06/12/2023]
Abstract
We use cathodoluminescence (CL) spectroscopy in a transmission electron microscope to probe the radial breathing mode of plasmonic silver nanodisks. A two-mirror detection system sandwiching the sample collects the CL emission in both directions, that is, backward and forward with respect to the electron beam trajectory. We unambiguously identify a spectral shift of about 8 nm in the CL spectra acquired from both sides and show that this asymmetry is induced by the electron beam itself. By numerical simulations, we confirm the observations and identify the underlying physical effect due to the interference of the CL emission patterns of an electron-beam-induced dipole and the breathing mode. This effect can ultimately limit the achievable fidelity in CL measurements on any system involving multiple excitations and should therefore be considered with care in high-precision experiments.
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Affiliation(s)
| | - Arthur Losquin
- Thales
Research and Technology, 1 avenue Augustin Fresnel, Palaiseau 91767, France
| | - Michal Horák
- Central
European Institute of Technology, Brno University
of Technology, Brno Purkynǒva 123, 612 00, Czech Republic
| | - Ulrich Hohenester
- Institute
of Physics, University of Graz, Universitätsplatz 5, Graz 8010, Austria
| | - Michael Stöger-Pollach
- University
Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10, Wien 1040, Austria
| | - Joachim R. Krenn
- Institute
of Physics, University of Graz, Universitätsplatz 5, Graz 8010, Austria
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27
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Sutter P, Khorashad LK, Argyropoulos C, Sutter E. Cathodoluminescence of Ultrathin Twisted Ge 1- x Sn x S van der Waals Nanoribbon Waveguides. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2006649. [PMID: 33283337 DOI: 10.1002/adma.202006649] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Ultrathin van der Waals semiconductors have shown extraordinary optoelectronic and photonic properties. Propagating photonic modes make layered crystal waveguides attractive for photonic circuitry and for studying hybrid light-matter states. Accessing guided modes by conventional optics is challenging due to the limited spatial resolution and poor out-of-plane far-field coupling. Scanning near-field optical microscopy can overcome these issues and can characterize waveguide modes down to a resolution of tens of nanometers, albeit for planar samples or nanostructures with moderate height variations. Electron microscopy provides atomic-scale localization also for more complex geometries, and recent advances have extended the accessible excitations from interband transitions to phonons. Here, bottom-up synthesized layered semiconductor (Ge1- x Snx S) nanoribbons with an axial twist and deep subwavelength thickness are demonstrated as a platform for realizing waveguide modes, and cathodoluminescence spectroscopy is introduced as a tool to characterize them. Combined experiments and simulations show the excitation of guided modes by the electron beam and their efficient detection via photons emitted in the ribbon plane, which enables the measurement of key properties such as the evanescent field into the vacuum cladding with nanometer resolution. The results identify van der Waals waveguides operating in the infrared and highlight an electron-microscopy-based approach for probing complex-shaped nanophotonic structures.
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Affiliation(s)
- Peter Sutter
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | | | - Christos Argyropoulos
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Eli Sutter
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
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28
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DiStefano JG, Murthy AA, Hao S, Dos Reis R, Wolverton C, Dravid VP. Topology of transition metal dichalcogenides: the case of the core-shell architecture. NANOSCALE 2020; 12:23897-23919. [PMID: 33295919 DOI: 10.1039/d0nr06660e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Non-planar architectures of the traditionally flat 2D materials are emerging as an intriguing paradigm to realize nascent properties within the family of transition metal dichalcogenides (TMDs). These non-planar forms encompass a diversity of curvatures, morphologies, and overall 3D architectures that exhibit unusual characteristics across the hierarchy of length-scales. Topology offers an integrated and unified approach to describe, harness, and eventually tailor non-planar architectures through both local and higher order geometry. Topological design of layered materials intrinsically invokes elements highly relevant to property manipulation in TMDs, such as the origin of strain and its accommodation by defects and interfaces, which have broad implications for improved material design. In this review, we discuss the importance and impact of geometry on the structure and properties of TMDs. We present a generalized geometric framework to classify and relate the diversity of possible non-planar TMD forms. We then examine the nature of curvature in the emerging core-shell architecture, which has attracted high interest due to its versatility and design potential. We consider the local structure of curved TMDs, including defect formation, strain, and crystal growth dynamics, and factors affecting the morphology of core-shell structures, such as synthesis conditions and substrate morphology. We conclude by discussing unique aspects of TMD architectures that can be leveraged to engineer targeted, exotic properties and detail how advanced characterization tools enable detection of these features. Varying the topology of nanomaterials has long served as a potent methodology to engineer unusual and exotic properties, and the time is ripe to apply topological design principles to TMDs to drive future nanotechnology innovation.
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Affiliation(s)
- Jennifer G DiStefano
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
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29
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Peña Román RJ, Auad Y, Grasso L, Alvarez F, Barcelos ID, Zagonel LF. Tunneling-current-induced local excitonic luminescence in p-doped WSe 2 monolayers. NANOSCALE 2020; 12:13460-13470. [PMID: 32614018 DOI: 10.1039/d0nr03400b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We have studied the excitonic properties of exfoliated tungsten diselenide (WSe2) monolayers transferred to gold substrates using the tunneling current in a Scanning Tunneling Microscope (STM) operated in air to excite the light emission locally. In obtained spectra, emission energies are independent of the applied bias voltage and resemble photoluminescence (PL) results, indicating that, in both cases, the light emission is due to neutral and charged exciton recombination. Interestingly, the electron injection rate, that is, the tunneling current, can be used to control the ratio of charged to neutral exciton emission. The obtained quantum yield in the transition metal dichalcogenide (TMD) is ∼5 × 10-7 photons per electron. The proposed excitation mechanism is the direct injection of carriers into the conduction band. The monolayer WSe2 presents bright and dark defects spotted by STM images performed under UHV. STS confirms the sample as p-doped, possibly as a net result of the observed defects. The presence of an interfacial water layer decouples the monolayer from the gold support and allows excitonic emission from the WSe2 monolayer. The creation of a water layer is an inherent feature of the sample transferring process due to the ubiquitous air moisture. Consequently, vacuum thermal annealing, which removes the water layer, quenches excitonic luminescence from the TMD. The tunneling current can locally displace water molecules leading to excitonic emission quenching and to plasmonic emission due to the gold substrate. The present findings extend the use and the understanding of STM induced light emission (STM-LE) on semiconducting TMDs to probe exciton emission and dynamics with high spatial resolution.
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Affiliation(s)
- Ricardo Javier Peña Román
- Applied Physics Department, "Gleb Wataghin" Institute of Physics, University of Campinas - UNICAMP, 13083-859, Campinas, SP, Brazil.
| | - Yves Auad
- Applied Physics Department, "Gleb Wataghin" Institute of Physics, University of Campinas - UNICAMP, 13083-859, Campinas, SP, Brazil.
| | - Lucas Grasso
- Applied Physics Department, "Gleb Wataghin" Institute of Physics, University of Campinas - UNICAMP, 13083-859, Campinas, SP, Brazil.
| | - Fernando Alvarez
- Applied Physics Department, "Gleb Wataghin" Institute of Physics, University of Campinas - UNICAMP, 13083-859, Campinas, SP, Brazil.
| | - Ingrid David Barcelos
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-970, Campinas, SP, Brazil
| | - Luiz Fernando Zagonel
- Applied Physics Department, "Gleb Wataghin" Institute of Physics, University of Campinas - UNICAMP, 13083-859, Campinas, SP, Brazil.
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30
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Affiliation(s)
- Dongdong Xiao
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- School of physical sciencesUniversity of Chinese Academy of Sciences Beijing 100049 China
- Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China
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31
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Zobelli A, Woo SY, Tararan A, Tizei LH, Brun N, Li X, Stéphan O, Kociak M, Tencé M. Spatial and spectral dynamics in STEM hyperspectral imaging using random scan patterns. Ultramicroscopy 2020; 212:112912. [DOI: 10.1016/j.ultramic.2019.112912] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/12/2019] [Accepted: 11/22/2019] [Indexed: 12/19/2022]
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32
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Gover A, Yariv A. Free-Electron-Bound-Electron Resonant Interaction. PHYSICAL REVIEW LETTERS 2020; 124:064801. [PMID: 32109105 DOI: 10.1103/physrevlett.124.064801] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 12/02/2019] [Accepted: 01/13/2020] [Indexed: 05/27/2023]
Abstract
Here we present a new paradigm of free-electron-bound-electron resonant interaction. This concept is based on a recent demonstration of the optical frequency modulation of the free-electron quantum electron wave function (QEW) by an ultrafast laser beam. We assert that pulses of such QEWs correlated in their modulation phase, interact resonantly with two-level systems, inducing resonant quantum transitions when the transition energy ΔE=ℏω_{21} matches a harmonic of the modulation frequency ω_{21}=nω_{b}. Employing this scheme for resonant cathodoluminescence and resonant EELS combines the atomic level spatial resolution of electron microscopy with the high spectral resolution of lasers.
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Affiliation(s)
- Avraham Gover
- Department of Electrical Engineering Physical Electronics, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Amnon Yariv
- California Institute of Technology (Caltech), Pasadena, California 91125, USA
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33
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Polman A, Kociak M, García de Abajo FJ. Electron-beam spectroscopy for nanophotonics. NATURE MATERIALS 2019; 18:1158-1171. [PMID: 31308514 DOI: 10.1038/s41563-019-0409-1] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 05/04/2019] [Accepted: 05/14/2019] [Indexed: 05/22/2023]
Abstract
Progress in electron-beam spectroscopies has recently enabled the study of optical excitations with combined space, energy and time resolution in the nanometre, millielectronvolt and femtosecond domain, thus providing unique access into nanophotonic structures and their detailed optical responses. These techniques rely on ~1-300 keV electron beams focused at the sample down to sub-nanometre spots, temporally compressed in wavepackets a few femtoseconds long, and in some cases controlled by ultrafast light pulses. The electrons undergo energy losses and gains (also giving rise to cathodoluminescence light emission), which are recorded to reveal the optical landscape along the beam path. This Review portraits these advances, with a focus on coherent excitations, emphasizing the increasing level of control over the electron wavefunctions and ensuing applications in the study and technological use of optically resonant modes and polaritons in nanoparticles, 2D materials and engineered nanostructures.
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Affiliation(s)
- Albert Polman
- Center for Nanophotonics, AMOLF, Amsterdam, the Netherlands.
| | - Mathieu Kociak
- Laboratoire de Physique des Solides, Université de Paris-Sud, Orsay, France
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Reserca I Estudis Avançats, Barcelona, Spain
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34
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Radio, cathodo and photoluminescence investigations of high density WO3-Gd2O3-B2O3 glass doped with Tb3+. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2019.108350] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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35
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Zachman MJ, Hachtel JA, Idrobo JC, Chi M. Emerging Electron Microscopy Techniques for Probing Functional Interfaces in Energy Materials. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michael J. Zachman
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Jordan A. Hachtel
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Juan Carlos Idrobo
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Miaofang Chi
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
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36
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Zachman MJ, Hachtel JA, Idrobo JC, Chi M. Emerging Electron Microscopy Techniques for Probing Functional Interfaces in Energy Materials. Angew Chem Int Ed Engl 2019; 59:1384-1396. [PMID: 31081976 DOI: 10.1002/anie.201902993] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/01/2019] [Indexed: 11/10/2022]
Abstract
Interfaces play a fundamental role in many areas of chemistry. However, their localized nature requires characterization techniques with high spatial resolution in order to fully understand their structure and properties. State-of-the-art atomic resolution or in situ scanning transmission electron microscopy and electron energy-loss spectroscopy are indispensable tools for characterizing the local structure and chemistry of materials with single-atom resolution, but they are not able to measure many properties that dictate function, such as vibrational modes or charge transfer, and are limited to room-temperature samples containing no liquids. Here, we outline emerging electron microscopy techniques that are allowing these limitations to be overcome and highlight several recent studies that were enabled by these techniques. We then provide a vision for how these techniques can be paired with each other and with in situ methods to deliver new insights into the static and dynamic behavior of functional interfaces.
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Affiliation(s)
- Michael J Zachman
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jordan A Hachtel
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Juan Carlos Idrobo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Miaofang Chi
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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37
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Sutter E, Zhang B, Sun M, Sutter P. Few-Layer to Multilayer Germanium(II) Sulfide: Synthesis, Structure, Stability, and Optoelectronics. ACS NANO 2019; 13:9352-9362. [PMID: 31305983 DOI: 10.1021/acsnano.9b03986] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Among 2D/layered semiconductors, group IV monochalcogenides such as SnS(e) and GeS(e) have attracted attention as phosphorene/black phosphorus analogues with anisotropic structures and predicted unusual properties. In contrast to SnS, for which bottom-up synthesis has been reported, few-layer GeS has been realized primarily via exfoliation from bulk crystals. Here, we report the synthesis of large (up to >20 μm), faceted single crystalline GeS flakes with anisotropic properties using a vapor transport process. In situ electron microscopy is used to identify the thermal stability and sublimation pathways, and demonstrates that the GeS flakes are self-encapsulated in a thin, sulfur-rich amorphous GeSx shell during growth. The shell provides exceptional chemical stability to the layered GeS core. In contrast to exfoliated GeS, which rapidly degrades during exposure to air, the synthesized GeS-GeSx core-shell structures show no signs of chemical attack and remain unchanged in air for extended time periods. Measurements of the optoelectronic properties by photoluminescence spectroscopy show a tunable bandgap due to out-of-plane quantum confinement in flakes with thickness below 100 nm. Cathodoluminescence (CL) spectroscopy with nanoscale excitation provides evidence for interfacial charge transfer due to a type II heterojunction between the crystalline core and amorphous shell. Measurements by locally excited CL yield a minority carrier (electron) diffusion length in the p-type GeS core ldiff = 0.27 μm, on par with diffusion lengths in the highest-quality layered chalcogenide semiconductors.
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Affiliation(s)
- Eli Sutter
- Department of Mechanical and Materials Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Bo Zhang
- Department of Mechanical and Materials Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Muhua Sun
- Department of Mechanical and Materials Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Peter Sutter
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
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38
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Zamani RR, Arbiol J. Understanding semiconductor nanostructures via advanced electron microscopy and spectroscopy. NANOTECHNOLOGY 2019; 30:262001. [PMID: 30812017 DOI: 10.1088/1361-6528/ab0b0a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Transmission electron microscopy (TEM) offers an ample range of complementary techniques which are able to provide essential information about the physical, chemical and structural properties of materials at the atomic scale, and hence makes a vast impact on our understanding of materials science, especially in the field of semiconductor one-dimensional (1D) nanostructures. Recent advancements in TEM instrumentation, in particular aberration correction and monochromation, have enabled pioneering experiments in complex nanostructure material systems. This review aims to address these understandings through the applications of the methodology for semiconductor nanostructures. It points out various electron microscopy techniques, in particular scanning TEM (STEM) imaging and spectroscopy techniques, with their already-employed or potential applications on 1D nanostructured semiconductors. We keep the main focus of the paper on the electronic and optoelectronic properties of such semiconductors, and avoid expanding it further. In the first part of the review, we give a brief introduction to each of the STEM-based techniques, without detailed elaboration, and mention the recent technological and conceptual developments which lead to novel characterization methodologies. For further reading, we refer the audience to a handful of papers in the literature. In the second part, we highlight the recent examples of application of the STEM methodology on the 1D nanostructure semiconductor materials, especially III-V, II-V, and group IV bare and heterostructure systems. The aim is to address the research questions on various physical properties and introduce solutions by choosing the appropriate technique that can answer the questions. Potential applications will also be discussed, the ones that have already been used for bulk and 2D materials, and have shown great potential and promise for 1D nanostructure semiconductors.
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Affiliation(s)
- Reza R Zamani
- Department of Physics, Chalmers University of Technology, Gothenburg, SE-41296, Sweden. Interdisciplinary Centre for Electron Microscopy (CIME), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
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39
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Sutter P, Wimer S, Sutter E. Chiral twisted van der Waals nanowires. Nature 2019; 570:354-357. [DOI: 10.1038/s41586-019-1147-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/25/2019] [Indexed: 11/10/2022]
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40
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Schefold J, Meuret S, Schilder N, Coenen T, Agrawal H, Garnett EC, Polman A. Spatial Resolution of Coherent Cathodoluminescence Super-Resolution Microscopy. ACS PHOTONICS 2019; 6:1067-1072. [PMID: 31024982 PMCID: PMC6473507 DOI: 10.1021/acsphotonics.9b00164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Indexed: 05/29/2023]
Abstract
We investigate the nanoscale excitation of Ag nanocubes with coherent cathodoluminescence imaging spectroscopy (CL) to resolve the factors that determine the spatial resolution of CL as a deep-subwavelength imaging technique. The 10-30 keV electron beam coherently excites localized plasmons in 70 nm Ag cubes at 2.4 and 3.1 eV. The radiation from these plasmon modes is collected in the far-field together with the secondary electron intensity. CL line scans across the nanocubes show exponentially decaying tails away from the cube that reveal the evanescent coupling of the electron field to the resonant plasmon modes. The measured CL decay lengths range from 8 nm (10 keV) to 12 nm (30 keV) and differ from the calculated ones by only 1-3 nm. A statistical model of electron scattering inside the Ag nanocubes is developed to analyze the secondary electron images and compare them with the CL data. The Ag nanocube edges are derived from the CL line scans with a systematic error less than 3 nm. The data demonstrate that CL probes the electron-induced plasmon fields with nanometer accuracy.
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Affiliation(s)
- Joris Schefold
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Sophie Meuret
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Nick Schilder
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Toon Coenen
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
- Delmic B.V., Kanaalweg
4, 2628
EB Delft, The Netherlands
| | - Harshal Agrawal
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Erik C. Garnett
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Albert Polman
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
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41
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Guo S, Talebi N, Campos A, Kociak M, van Aken PA. Radiation of Dynamic Toroidal Moments. ACS PHOTONICS 2019; 6:467-474. [PMID: 31523699 PMCID: PMC6735299 DOI: 10.1021/acsphotonics.8b01422] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Indexed: 05/27/2023]
Abstract
Dynamic toroidal dipoles, a distinguished class of fundamental electromagnetic sources, receive increasing interest and participate in fascinating electrodynamic phenomena and sensing applications. As described in the literature, the radiative nature of dynamic toroidal dipoles is sometimes confounded, intermixing with static toroidal dipoles and plasmonic dark modes. Here, we elucidate this issue and provide proof-of-principle experiments exclusively on the radiation behavior of dynamic toroidal moments. Optical toroidal modes in plasmonic heptamer nanocavities are analyzed by electron energy loss spectroscopy and energy-filtered transmission electron microscopy supported by finite-difference time-domain numerical calculations. Additionally, their corresponding radiation behaviors are experimentally investigated by means of cathodoluminescence. The observed contrasting behaviors of a single dynamic toroidal dipole mode and an antiparallel toroidal dipole pair mode are discussed and elucidated. Our findings further clarify the electromagnetic properties of dynamic toroidal dipoles and serve as important guidance for the use of toroidal dipole moments in future applications.
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Affiliation(s)
- Surong Guo
- Stuttgart
Center for Electron Microscopy, Max Planck
Institute for Solid State Research, Heisenbergstrasse 1, Stuttgart 70569, Germany
| | - Nahid Talebi
- Stuttgart
Center for Electron Microscopy, Max Planck
Institute for Solid State Research, Heisenbergstrasse 1, Stuttgart 70569, Germany
| | - Alfredo Campos
- Laboratoire
de Physique des Solides, Université
Paris Sud, Orsay 91400, France
| | - Mathieu Kociak
- Laboratoire
de Physique des Solides, Université
Paris Sud, Orsay 91400, France
| | - Peter A. van Aken
- Stuttgart
Center for Electron Microscopy, Max Planck
Institute for Solid State Research, Heisenbergstrasse 1, Stuttgart 70569, Germany
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42
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Kennedy OW, White ER, Howkins A, Williams CK, Boyd IW, Warburton PA, Shaffer MSP. Mapping the Origins of Luminescence in ZnO Nanowires by STEM-CL. J Phys Chem Lett 2019; 10:386-392. [PMID: 30614706 DOI: 10.1021/acs.jpclett.8b03286] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In semiconductor nanowires, understanding both the sources of luminescence (excitonic recombination, defects, etc.) and the distribution of luminescent centers (be they uniformly distributed, or concentrated at structural defects or at the surface) is important for synthesis and applications. We develop scanning transmission electron microscopy-cathodoluminescence (STEM-CL) measurements, allowing the structure and cathodoluminescence (CL) of single ZnO nanowires to be mapped at high resolution. Using a CL pixel resolution of 10 nm, variations of the CL spectra within such nanowires in the direction perpendicular to the nanowire growth axis are identified for the first time. By comparing the local CL spectra with the bulk photoluminescence spectra, the CL spectral features are assigned to internal and surface defect structures. Hyperspectral CL maps are deconvolved to enable characteristic spectral features to be spatially correlated with structural features within single nanowires. We have used these maps to show that the spatial distribution of these defects correlates well with regions that show an increased rate of nonradiative transitions.
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Affiliation(s)
- Oscar W Kennedy
- London Centre for Nanotechnology , University College London , London WC1H 0AH , United Kingdom
- Department of Electronic and Electrical Engineering , University College London , London WC1E 7JE , United Kingdom
| | - Edward R White
- Department of Chemistry , Imperial College London , London SW7 2AZ , United Kingdom
| | - Ashley Howkins
- Experimental Techniques Centre , Brunel University London , Uxbridge UB8 3PH , United Kingdom
| | | | - Ian W Boyd
- Experimental Techniques Centre , Brunel University London , Uxbridge UB8 3PH , United Kingdom
| | - Paul A Warburton
- London Centre for Nanotechnology , University College London , London WC1H 0AH , United Kingdom
- Department of Electronic and Electrical Engineering , University College London , London WC1E 7JE , United Kingdom
| | - Milo S P Shaffer
- Department of Chemistry , Imperial College London , London SW7 2AZ , United Kingdom
- Departmental of Materials , Imperial College London , London , SW7 2AZ , United Kingdom
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43
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Sun X, Berenschot EJW, Veltkamp HW, Gardeniers HJGE, Tas NR. Scalable 3D Nanoparticle Trap for Electron Microscopy Analysis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1803283. [PMID: 30324725 DOI: 10.1002/smll.201803283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 09/24/2018] [Indexed: 06/08/2023]
Abstract
Arrays of nanoscale pyramidal cages embedded in a silicon nitride membrane are fabricated with an order of magnitude miniaturization in the size of the cages compared to previous work. This becomes possible by combining the previously published wafer-scale corner lithography process with displacement Talbot lithography, including an additional resist etching step that allows the creation of masking dots with a size down to 50 nm, using a conventional 365 nm UV source. The resulting pyramidal cages have different entrance and exit openings, which allows trapping of nanoparticles within a predefined size range. The cages are arranged in a well-defined array, which guarantees traceability of individual particles during post-trapping analysis. Gold nanoparticles with a size of 25, 150, and 200 nm are used to demonstrate the trapping capability of the fabricated devices. The traceability of individual particles is demonstrated by transferring the transmission electron microscopy (TEM) transparent devices between scanning electron microscopy and TEM instruments and relocating a desired collection of particles.
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Affiliation(s)
- Xingwu Sun
- Mesoscale Chemical Systems, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
| | - Erwin J W Berenschot
- Mesoscale Chemical Systems, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
| | - Henk-Willem Veltkamp
- Integrated Devices and Systems, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
| | - Han J G E Gardeniers
- Mesoscale Chemical Systems, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
| | - Niels R Tas
- Mesoscale Chemical Systems, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
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44
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Myroshnychenko V, Nishio N, García de Abajo FJ, Förstner J, Yamamoto N. Unveiling and Imaging Degenerate States in Plasmonic Nanoparticles with Nanometer Resolution. ACS NANO 2018; 12:8436-8446. [PMID: 30067900 DOI: 10.1021/acsnano.8b03926] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Metal nanoparticles host localized plasmon excitations that allow the manipulation of optical fields at the nanoscale. Despite the availability of several techniques for imaging plasmons, direct access into the symmetries of these excitations remains elusive, thus hindering progress in the development of applications. Here, we present a combination of angle-, polarization-, and space-resolved cathodoluminescence spectroscopy methods to selectively access the symmetry and degeneracy of plasmonic states in lithographically fabricated gold nanoprisms. We experimentally reveal and spatially map degenerate states of multipole plasmon modes with nanometer spatial resolution and further provide recipes for resolving optically dark and out-of-plane modes. Full-wave simulations in conjunction with a simple tight-binding model explain the complex plasmon structure in these particles and reveal intriguing mode-symmetry phenomena. Our approach introduces systematics for a comprehensive symmetry characterization of plasmonic states in high-symmetry nanostructures.
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Affiliation(s)
- Viktor Myroshnychenko
- Institute of Electrical Engineering , Paderborn University , Warburger Straße 100 , D-33098 Paderborn , Germany
| | - Natsuki Nishio
- Physics Department , Tokyo Institute of Technology , Meguro-ku, Tokyo , 152-8551 Japan
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology , 08860 Castelldefels (Barcelona) , Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats , Passeig Lluís Companys, 23 , 08010 Barcelona , Spain
| | - Jens Förstner
- Institute of Electrical Engineering , Paderborn University , Warburger Straße 100 , D-33098 Paderborn , Germany
| | - Naoki Yamamoto
- Physics Department , Tokyo Institute of Technology , Meguro-ku, Tokyo , 152-8551 Japan
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45
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Sutter P, Argyropoulos C, Sutter E. Germanium Sulfide Nano-Optics Probed by STEM-Cathodoluminescence Spectroscopy. NANO LETTERS 2018; 18:4576-4583. [PMID: 29883126 DOI: 10.1021/acs.nanolett.8b01840] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nano-optical studies of confined modes in planar waveguides have attracted significant interest as a means to probe exciton-polaritons and other hybrid light-matter quasiparticles in layered semiconductors, such as transition metal dichalcogenides or boron nitride. There is a need to broaden such studies to other materials and to identify alternatives to scanning near-field optical microscopy for exciting and measuring confined waveguide modes. Here, we establish an approach for probing the dispersion of traveling waveguide modes by cathodoluminescence spectroscopy excited by the focused electron beam in scanning transmission electron microscopy (STEM-CL) and apply it to solid-state resonators consisting of mesoscale monocrystalline prisms and plates composed of GeS, an anisotropic layered semiconductor with direct bandgap in the near-infrared spectral range. Structure, crystallography, and chemical composition of the mesostructures are analyzed by analytical electron microscopy. STEM-CL maps and spectra show pronounced interference effects and sharp emission peaks at photon energies below the fundamental bandgap of GeS. Our analysis demonstrates that locally excited light emission in STEM-CL launches in-plane waveguide modes in the mesoscale GeS structures, which are internally reflected by highly specular GeS edges to cause interference of the waveguide modes. Reabsorption and secondary luminescence give rise to the intensity modulations detected in the far field. Our results highlight avenues for probing light-matter interactions below the diffraction limit in a wide range of quantum materials and open up the possibility of tuning light emission geometrically using interference rather than by the conventional bandgap engineering.
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46
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Guillemé P, Stervinou J, Rohel T, Cornet C, Gachet D, Balac S, Mahé F, Dumeige Y, Léger Y. Cathodoluminescence hyperspectral analysis of whispering gallery modes in active semiconductor wedge resonators. OPTICS LETTERS 2018; 43:1766-1769. [PMID: 29652359 DOI: 10.1364/ol.43.001766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 03/15/2018] [Indexed: 06/08/2023]
Abstract
Whispering gallery mode resonators are key devices for integrated photonics. Despite their generalization in fundamental and applied science, information on spatial confinement of light in these structures is mostly retrieved from purely spectral analysis. In this work, we present a detailed spectral and spatial characterization of whispering gallery modes in active semiconductor microdisk resonators by use of hyperspectral cathodoluminescence. By comparing our experimental findings to finite element simulations, we demonstrate that the combination of spectral and spatial measurements enables unique identification of the modes and even reveals specific features of the microresonator geometry, such as a wedge profile.
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47
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Deitz JI, Sarwar ATMG, Carnevale SD, Grassman TJ, Myers RC, McComb DW. Nano-Cathodoluminescence Measurement of Asymmetric Carrier Trapping and Radiative Recombination in GaN and InGaN Quantum Disks. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2018; 24:93-98. [PMID: 29699596 DOI: 10.1017/s143192761800017x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The ability to characterize recombination and carrier trapping processes in group-III nitride-based nanowires is vital to further improvements in their overall efficiencies. While advances in scanning transmission electron microscope (STEM)-based cathodoluminescence (CL) have offered some insight into nanowire behavior, inconsistencies in nanowire emission along with CL detector limitations have resulted in the incomplete understanding in nanowire emission processes. Here, two nanowire heterostructures were explored with STEM-CL: a polarization-graded AlGaN nanowire light-emitting diode (LED) with a GaN quantum disk and a polarization-graded AlGaN nanowire with three different InGaN quantum disks. Most nanowires explored in this study did not emit. For the wires that did emit in both structures, they exhibited asymmetrical emission consistent with the polarization-induced electric fields in the barrier regions of the nano-LEDs. In the AlGaN/InGaN sample, two of the quantum disks exhibited no emission potentially due to the three-dimensional landscape of the sample or due to limitations in the CL detection.
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Affiliation(s)
- Julia I Deitz
- 1Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - A T M Golam Sarwar
- 2Department of Electrical and Computer Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - Santino D Carnevale
- 2Department of Electrical and Computer Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - Tyler J Grassman
- 1Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - Roberto C Myers
- 1Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - David W McComb
- 1Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA
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48
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Schmidt FP, Losquin A, Hofer F, Hohenau A, Krenn JR, Kociak M. How Dark Are Radial Breathing Modes in Plasmonic Nanodisks? ACS PHOTONICS 2018; 5:861-866. [PMID: 29607350 PMCID: PMC5871341 DOI: 10.1021/acsphotonics.7b01060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Indexed: 05/06/2023]
Abstract
Due to a vanishing dipole moment, radial breathing modes in small flat plasmonic nanoparticles do not couple to light and have to be probed with a near-field source, as in electron energy loss spectroscopy (EELS). With increasing particle size, retardation gives rise to light coupling, enabling probing breathing modes optically or by cathodoluminescence (CL). Here, we investigate single silver nanodisks with diameters of 150-500 nm by EELS and CL in an electron microscope and quantify the EELS/CL ratio, which corresponds to the ratio of full to radiative damping of the breathing mode. For the investigated diameter range, we find the CL signal to increase by about 1 order of magnitude, in agreement with numerical simulations. Due to reciprocity, our findings corroborate former optical experiments and enable a quantitative understanding of the light coupling of dark plasmonic modes.
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Affiliation(s)
- Franz-Philipp Schmidt
- Institute
of Physics, University of Graz, Graz 8010, Austria
- Institute
for Electron Microscopy and Nanoanalysis, Graz University of Technology, Graz 8010, Austria
- E-mail:
| | - Arthur Losquin
- Department
of Physics, Lund University, Lund 221 00, Sweden
- Laboratoire
Ondes et Matière d’Aquitaine, UMR 5798, CNRS-University of Bordeaux, F-33405 Talence Cedex, France
| | - Ferdinand Hofer
- Institute
for Electron Microscopy and Nanoanalysis, Graz University of Technology, Graz 8010, Austria
| | - Andreas Hohenau
- Institute
of Physics, University of Graz, Graz 8010, Austria
| | | | - Mathieu Kociak
- Laboratoire
de Physique des Solides, CNRS UMR 8502,
Université Paris-Sud, 91405 Orsay, France
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49
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Hsieh FJ, Chen YW, Huang YK, Lee HM, Lin CH, Chang HC. Correlative Light-Electron Microscopy of Lipid-Encapsulated Fluorescent Nanodiamonds for Nanometric Localization of Cell Surface Antigens. Anal Chem 2018; 90:1566-1571. [PMID: 29257684 DOI: 10.1021/acs.analchem.7b04549] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Containing an ensemble of nitrogen-vacancy centers in crystal matrices, fluorescent nanodiamonds (FNDs) are a new type of photostable markers that have found wide applications in light microscopy. The nanomaterial also has a dense carbon core, making it visible to electron microscopy. Here, we show that FNDs encapsulated in biotinylated lipids (bLs) are useful for subdiffraction imaging of antigens on cell surface with correlative light-electron microscopy (CLEM). The lipid encapsulation enables not only good dispersion of the particles in biological buffers but also high specific labeling of live cells. By employing the bL-encapsulated FNDs to target CD44 on HeLa cell surface through biotin-mediated immunostaining, we obtained the spatial distribution of these antigens by CLEM with a localization accuracy of ∼50 nm in routine operations. A comparative study with dual-color imaging, in which CD44 was labeled with FND and MICA/MICB was labeled with Alexa Fluor 488, demonstrated the superior performance of FNDs as fluorescent fiducial markers for CLEM of cell surface antigens.
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Affiliation(s)
- Feng-Jen Hsieh
- Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 106, Taiwan.,Taiwan International Graduate Program - Chemical Biology and Molecular Biophysics, Academia Sinica , Taipei 115, Taiwan.,Department of Biochemical Sciences, National Taiwan University , Taipei 106, Taiwan
| | - Yen-Wei Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 106, Taiwan
| | - Yao-Kuan Huang
- Institute of Cellular and Organismic Biology, Academia Sinica , Taipei 115, Taiwan
| | - Hsien-Ming Lee
- Institute of Chemistry, Academia Sinica , Taipei 115, Taiwan
| | - Chun-Hung Lin
- Taiwan International Graduate Program - Chemical Biology and Molecular Biophysics, Academia Sinica , Taipei 115, Taiwan.,Department of Biochemical Sciences, National Taiwan University , Taipei 106, Taiwan.,Institute of Biological Chemistry, Academia Sinica , Taipei 115, Taiwan
| | - Huan-Cheng Chang
- Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 106, Taiwan.,Department of Chemical Engineering, National Taiwan University of Science and Technology , Taipei 106, Taiwan
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50
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Houdellier F, Caruso GM, Weber S, Kociak M, Arbouet A. Development of a high brightness ultrafast Transmission Electron Microscope based on a laser-driven cold field emission source. Ultramicroscopy 2017; 186:128-138. [PMID: 29306810 DOI: 10.1016/j.ultramic.2017.12.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 12/18/2017] [Accepted: 12/22/2017] [Indexed: 11/28/2022]
Abstract
We report on the development of an ultrafast Transmission Electron Microscope based on a cold field emission source which can operate in either DC or ultrafast mode. Electron emission from a tungsten nanotip is triggered by femtosecond laser pulses which are tightly focused by optical components integrated inside a cold field emission source close to the cathode. The properties of the electron probe (brightness, angular current density, stability) are quantitatively determined. The measured brightness is the largest reported so far for UTEMs. Examples of imaging, diffraction and spectroscopy using ultrashort electron pulses are given. Finally, the potential of this instrument is illustrated by performing electron holography in the off-axis configuration using ultrashort electron pulses.
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Affiliation(s)
- F Houdellier
- CEMES-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse, France.
| | - G M Caruso
- CEMES-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse, France
| | - S Weber
- CEMES-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse, France
| | - M Kociak
- Laboratoire de Physique des Solides, Université Paris Sud, Bâtiment 510, UMR CNRS 8502, Orsay 91400, France
| | - A Arbouet
- CEMES-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse, France.
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