1
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Bucher T, Ruimy R, Tsesses S, Dahan R, Bartal G, Vanacore GM, Kaminer I. Free-electron Ramsey-type interferometry for enhanced amplitude and phase imaging of nearfields. Sci Adv 2023; 9:eadi5729. [PMID: 38134276 PMCID: PMC10745688 DOI: 10.1126/sciadv.adi5729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 11/22/2023] [Indexed: 12/24/2023]
Abstract
The complex range of interactions between electrons and electromagnetic fields gave rise to countless scientific and technological advances. A prime example is photon-induced nearfield electron microscopy (PINEM), enabling the detection of confined electric fields in illuminated nanostructures with unprecedented spatial resolution. However, PINEM is limited by its dependence on strong fields, making it unsuitable for sensitive samples, and its inability to resolve complex phasor information. Here, we leverage the nonlinear, overconstrained nature of PINEM to present an algorithmic microscopy approach, achieving far superior nearfield imaging capabilities. Our algorithm relies on free-electron Ramsey-type interferometry to produce orders-of-magnitude improvement in sensitivity and ambiguity-immune nearfield phase reconstruction, both of which are optimal when the electron exhibits a fully quantum behavior. Our results demonstrate the potential of combining algorithmic approaches with state-of-the-art modalities in electron microscopy and may lead to various applications from imaging sensitive biological samples to performing full-field tomography of confined light.
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Affiliation(s)
- Tomer Bucher
- Andrew and Erna Viterbi Department of Electrical and Computer Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Ron Ruimy
- Andrew and Erna Viterbi Department of Electrical and Computer Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Shai Tsesses
- Andrew and Erna Viterbi Department of Electrical and Computer Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Raphael Dahan
- Solid State Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Guy Bartal
- Andrew and Erna Viterbi Department of Electrical and Computer Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Giovanni Maria Vanacore
- Department of Material Science, University of Milano-Bicocca, Via Cozzi 55, 20121 Milano, Italy
| | - Ido Kaminer
- Andrew and Erna Viterbi Department of Electrical and Computer Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
- Solid State Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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2
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Vanacore GM. Coherent Manipulation of Ultrashort Free Electrons Pulses via Quantized Electron-Photon Interaction Mediated by Transversely- and Longitudinally-Shaped Optical Fields. Microscopy and Microanalysis 2023; 29:377. [PMID: 37613326 DOI: 10.1093/micmic/ozad067.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Giovanni Maria Vanacore
- Laboratory of Ultrafast Microscopy for Nanoscale Dynamics (LUMiNaD), Department of Materials Science, University of Milano-Bicocca, Milano, Italy
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3
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Dias EJC, Madan I, Gargiulo S, Barantani F, Yannai M, Vanacore GM, Kaminer I, Carbone F, García de Abajo FJ. Generation and control of localized terahertz fields in photoemitted electron plasmas. Nanoscale Adv 2023; 5:3634-3645. [PMID: 37441257 PMCID: PMC10334422 DOI: 10.1039/d3na00168g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 05/02/2023] [Indexed: 07/15/2023]
Abstract
Dense micron-sized electron plasmas, such as those generated upon irradiation of nanostructured metallic surfaces by intense femtosecond laser pulses, constitute a rich playground to study light-matter interactions, many-body phenomena, and out-of-equilibrium charge dynamics. Besides their fundamental interest, laser-induced plasmas hold great potential for the generation of localized terahertz radiation pulses. However, the underlying mechanisms ruling the formation and evolution of such plasmas are not yet well understood. Here, we develop a comprehensive microscopic theory to predictably describe the spatiotemporal dynamics of laser-pulse-induced plasmas. Through detailed analysis of electron emission, metal screening, and plasma cloud interactions, we investigate the spatial, temporal, and spectral characteristics of the so-generated terahertz fields, which can be extensively controlled through the metal morphology and the illumination conditions. We further describe the interaction with femtosecond electron beams to explain recent ultrafast electron microscopy experiments, whereby the position and temporal dependence of the observed electron acceleration permits assessing the associated terahertz field. Besides its potential application to the design of low-frequency light sources, our work contributes fundamental insight into the generation and dynamics of micron-scale electron plasmas and their interaction with ultrafast electron pulses.
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Affiliation(s)
- Eduardo J C Dias
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology 08860 Castelldefels Barcelona Spain
| | - Ivan Madan
- Institute of Physics, École Polytechnique Fédérale de Lausanne Lausanne 1015 Switzerland
| | - Simone Gargiulo
- Institute of Physics, École Polytechnique Fédérale de Lausanne Lausanne 1015 Switzerland
| | - Francesco Barantani
- Institute of Physics, École Polytechnique Fédérale de Lausanne Lausanne 1015 Switzerland
- Department of Quantum Matter Physics, University of Geneva 24 Quai Ernest-Ansermet Geneva 1211 Switzerland
| | - Michael Yannai
- Technion - Israel Institute of Technology Haifa 3200003 Israel
| | - Giovanni Maria Vanacore
- Department of Materials Science, University of Milano-Bicocca Via Cozzi, 55 Milano 20126 Italy
| | - Ido Kaminer
- Technion - Israel Institute of Technology Haifa 3200003 Israel
| | - Fabrizio Carbone
- Institute of Physics, École Polytechnique Fédérale de Lausanne Lausanne 1015 Switzerland
| | - 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
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4
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Mecca S, Pallini F, Pinchetti V, Erroi A, Fappani A, Rossi F, Mattiello S, Vanacore GM, Brovelli S, Beverina L. Multigram-Scale Synthesis of Luminescent Cesium Lead Halide Perovskite Nanobricks for Plastic Scintillators. ACS Appl Nano Mater 2023; 6:9436-9443. [PMID: 37325014 PMCID: PMC10262149 DOI: 10.1021/acsanm.3c01146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023]
Abstract
Cesium lead halide perovskite nanocrystals of general formula CsPbX3 are having tremendous impact on a vast array of technologies requiring strong and tunable luminescence across the visible range and solutions processing. The development of plastic scintillators is just one of the many relevant applications. The syntheses are relatively simple but generally unsuitable to produce a large amount of material of reproducible quality required when moving from proof-of-concept scale to industrial applications. Wastes, particularly large amounts of lead-contaminated toxic and flammable organic solvents, are also an open issue. We describe a simple and reproducible procedure enabling the synthesis of luminescent CsPbX3 nanobricks of constant quality on a scale going from 0.12 to 8 g in a single batch. We also show complete recycling of the reaction wastes, leading to dramatically improved efficiency and sustainability.
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Affiliation(s)
- Sara Mecca
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
| | - Francesca Pallini
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
| | - Valerio Pinchetti
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
| | - Andrea Erroi
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
| | - Alice Fappani
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
| | - Francesca Rossi
- IMEM-CNR
Institute, Parco Area
delle Scienze 37/A, 43124 Parma, Italy
| | - Sara Mattiello
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
| | - Giovanni Maria Vanacore
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
| | - Sergio Brovelli
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
| | - Luca Beverina
- Department
of Materials Science, University of Milano-Bicocca, via R. Cozzi 55, I-20126 Milan, Italy
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5
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Konečná A, Rotunno E, Grillo V, García de Abajo FJ, Vanacore GM. Single-Pixel Imaging in Space and Time with Optically Modulated Free Electrons. ACS Photonics 2023; 10:1463-1472. [PMID: 37215321 PMCID: PMC10197172 DOI: 10.1021/acsphotonics.3c00047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Indexed: 05/24/2023]
Abstract
Single-pixel imaging, originally developed in light optics, facilitates fast three-dimensional sample reconstruction as well as probing with light wavelengths undetectable by conventional multi-pixel detectors. However, the spatial resolution of optics-based single-pixel microscopy is limited by diffraction to hundreds of nanometers. Here, we propose an implementation of single-pixel imaging relying on attainable modifications of currently available ultrafast electron microscopes in which optically modulated electrons are used instead of photons to achieve subnanometer spatially and temporally resolved single-pixel imaging. We simulate electron beam profiles generated by interaction with the optical field produced by an externally programmable spatial light modulator and demonstrate the feasibility of the method by showing that the sample image and its temporal evolution can be reconstructed using realistic imperfect illumination patterns. Electron single-pixel imaging holds strong potential for application in low-dose probing of beam-sensitive biological and molecular samples, including rapid screening during in situ experiments.
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Affiliation(s)
- Andrea Konečná
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
- Central
European Institute of Technology, Brno University of Technology, 612 00 Brno, Czech Republic
| | - Enzo Rotunno
- Centro
S3, Istituto di Nanoscienze-CNR, 41125 Modena, Italy
| | | | - F. Javier García de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
- ICREA-Institució
Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Giovanni Maria Vanacore
- Laboratory
of Ultrafast Microscopy for Nanoscale Dynamics (LUMiNaD), Department
of Materials Science, University of Milano-Bicocca, Via Cozzi 55, 20121 Milano, Italy
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6
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Yannai M, Dahan R, Gorlach A, Adiv Y, Wang K, Madan I, Gargiulo S, Barantani F, Dias EJC, Vanacore GM, Rivera N, Carbone F, García de Abajo FJ, Kaminer I. Ultrafast Electron Microscopy of Nanoscale Charge Dynamics in Semiconductors. ACS Nano 2023; 17:3645-3656. [PMID: 36736033 DOI: 10.1021/acsnano.2c10481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The ultrafast dynamics of charge carriers in solids plays a pivotal role in emerging optoelectronics, photonics, energy harvesting, and quantum technology applications. However, the investigation and direct visualization of such nonequilibrium phenomena remains as a long-standing challenge, owing to the nanometer-femtosecond spatiotemporal scales at which the charge carriers evolve. Here, we propose and demonstrate an interaction mechanism enabling nanoscale imaging of the femtosecond dynamics of charge carriers in solids. This imaging modality, which we name charge dynamics electron microscopy (CDEM), exploits the strong interaction of free-electron pulses with terahertz (THz) near fields produced by the moving charges in an ultrafast scanning transmission electron microscope. The measured free-electron energy at different spatiotemporal coordinates allows us to directly retrieve the THz near-field amplitude and phase, from which we reconstruct movies of the generated charges by comparison to microscopic theory. The CDEM technique thus allows us to investigate previously inaccessible spatiotemporal regimes of charge dynamics in solids, providing insight into the photo-Dember effect and showing oscillations of photogenerated electron-hole distributions inside a semiconductor. Our work facilitates the exploration of a wide range of previously inaccessible charge-transport phenomena in condensed matter using ultrafast electron microscopy.
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Affiliation(s)
- Michael Yannai
- Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Raphael Dahan
- Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Alexey Gorlach
- Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Yuval Adiv
- Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Kangpeng Wang
- Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Ivan Madan
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 6, Lausanne 1015, Switzerland
| | - Simone Gargiulo
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 6, Lausanne 1015, Switzerland
| | - Francesco Barantani
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 6, Lausanne 1015, Switzerland
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Eduardo J C Dias
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Giovanni Maria Vanacore
- Department of Materials Science, University of Milano-Bicocca, Via Cozzi 55, 20121 Milano, Italy
| | - Nicholas Rivera
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Fabrizio Carbone
- Institute of Physics, École Polytechnique Fédérale de Lausanne, Station 6, Lausanne 1015, Switzerland
| | - 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
| | - Ido Kaminer
- Technion - Israel Institute of Technology, Haifa 3200003, Israel
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7
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Madan I, Dias EJC, Gargiulo S, Barantani F, Yannai M, Berruto G, LaGrange T, Piazza L, Lummen TTA, Dahan R, Kaminer I, Vanacore GM, García de Abajo FJ, Carbone F. Charge Dynamics Electron Microscopy: Nanoscale Imaging of Femtosecond Plasma Dynamics. ACS Nano 2023; 17:3657-3665. [PMID: 36780289 PMCID: PMC9979644 DOI: 10.1021/acsnano.2c10482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Understanding and actively controlling the spatiotemporal dynamics of nonequilibrium electron clouds is fundamental for the design of light and electron sources, high-power electronic devices, and plasma-based applications. However, electron clouds evolve in a complex collective fashion on the nanometer and femtosecond scales, producing electromagnetic screening that renders them inaccessible to existing optical probes. Here, we solve the long-standing challenge of characterizing the evolution of electron clouds generated upon irradiation of metallic structures using an ultrafast transmission electron microscope to record the charged plasma dynamics. Our approach to charge dynamics electron microscopy (CDEM) is based on the simultaneous detection of electron-beam acceleration and broadening with nanometer/femtosecond resolution. By combining experimental results with comprehensive microscopic theory, we provide a deep understanding of this highly out-of-equilibrium regime, including previously inaccessible intricate microscopic mechanisms of electron emission, screening by the metal, and collective cloud dynamics. Beyond the present specific demonstration, the here-introduced CDEM technique grants us access to a wide range of nonequilibrium electrodynamic phenomena involving the ultrafast evolution of bound and free charges on the nanoscale.
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Affiliation(s)
- Ivan Madan
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | - Eduardo J. C. Dias
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona08860, Spain
| | - Simone Gargiulo
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | - Francesco Barantani
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
- Department
of Quantum Matter Physics, University of
Geneva, Geneva1211, Switzerland
| | - Michael Yannai
- Department
of Electrical and Computer Engineering, Technion Israel Institute of Technology, Haifa32000, Israel
| | - Gabriele Berruto
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | - Thomas LaGrange
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | - Luca Piazza
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
| | | | - Raphael Dahan
- Department
of Electrical and Computer Engineering, Technion Israel Institute of Technology, Haifa32000, Israel
| | - Ido Kaminer
- Department
of Electrical and Computer Engineering, Technion Israel Institute of Technology, Haifa32000, Israel
| | - Giovanni Maria Vanacore
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
- Department
of Materials Science, University of Milano-Bicocca, Milano20126, Italy
| | - F. Javier García de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona08860, Spain
- ICREA, Institució
Catalana de Recerca i Estudis Avançats, Barcelona08010, Spain
| | - Fabrizio Carbone
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne1015, Switzerland
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8
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Colombo E, Coppini DA, Maculan S, Seneci P, Santini B, Testa F, Salvioni L, Vanacore GM, Colombo M, Passarella D. Folic acid functionalization for targeting self-assembled paclitaxel-based nanoparticles. RSC Adv 2022; 12:35484-35493. [PMID: 36544466 PMCID: PMC9744106 DOI: 10.1039/d2ra06306a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
Hetero-nanoparticles self-assembled from a conjugate bearing folic acid as the targeting agent, and another bearing paclitaxel as the active agent are reported. Hetero-nanoparticles containing varying percentages of folic acid conjugates are characterised, and their biological activity is determined.
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Affiliation(s)
- Eleonora Colombo
- Dipartimento di Chimica, Università degli Studi di MilanoVia Golgi 1920133 MilanoItaly
| | - Davide Andrea Coppini
- Dipartimento di Chimica, Università degli Studi di MilanoVia Golgi 1920133 MilanoItaly
| | - Simone Maculan
- Dipartimento di Chimica, Università degli Studi di MilanoVia Golgi 1920133 MilanoItaly
| | - Pierfausto Seneci
- Dipartimento di Chimica, Università degli Studi di MilanoVia Golgi 1920133 MilanoItaly
| | - Benedetta Santini
- Dipartimento di Chimica, Università degli Studi di MilanoVia Golgi 1920133 MilanoItaly
| | - Filippo Testa
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano BicoccaPiazza della Scienza 220126 MilanoItaly
| | - Lucia Salvioni
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano BicoccaPiazza della Scienza 220126 MilanoItaly
| | - Giovanni Maria Vanacore
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano BicoccaVia Roberto Cozzi 5520125 MilanoItaly
| | - Miriam Colombo
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano BicoccaPiazza della Scienza 220126 MilanoItaly
| | - Daniele Passarella
- Dipartimento di Chimica, Università degli Studi di MilanoVia Golgi 1920133 MilanoItaly
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9
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Azadmand M, Vichi S, Cesura FG, Bietti S, Chrastina D, Bonera E, Vanacore GM, Tsukamoto S, Sanguinetti S. Vapour Liquid Solid Growth Effects on InGaN Epilayers Composition Uniformity in Presence of Metal Droplets. Nanomaterials (Basel) 2022; 12:3887. [PMID: 36364662 PMCID: PMC9659302 DOI: 10.3390/nano12213887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 10/23/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
We investigated the composition uniformity of InGaN epilayers in presence of metal droplets on the surface. We used Plasma Assisted MBE to grow an InGaN sample partially covered by metal droplets and performed structural and compositional analysis. The results showed a marked difference in indium incorporation between the region under the droplets and between them. Based on this observation we proposed a theoretical model able to explain the results by taking into account the vapour liquid solid growth that takes place under the droplet by direct impingement of nitrogen adatoms.
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Affiliation(s)
- Mani Azadmand
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Stefano Vichi
- INFN, Sezione di Milano-Bicocca, 20100 Milano, Italy
| | | | - Sergio Bietti
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Daniel Chrastina
- L-NESS, Physics Department, Politecnico di Milano, Via Anzani 42, 22100 Como, Italy
| | - Emiliano Bonera
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | | | - Shiro Tsukamoto
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
| | - Stefano Sanguinetti
- Department of Materials Science, University of Milano-Bicocca, 20100 Milano, Italy
- INFN, Sezione di Milano-Bicocca, 20100 Milano, Italy
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10
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Muhyuddin M, Testa D, Lorenzi R, Vanacore GM, Poli F, Soavi F, Specchia S, Giurlani W, Innocenti M, Rosi L, Santoro C. Iron-based electrocatalysts derived from scrap tires for oxygen reduction reaction: Evolution of synthesis-structure-performance relationship in acidic, neutral and alkaline media. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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11
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Madan I, Leccese V, Mazur A, Barantani F, LaGrange T, Sapozhnik A, Tengdin PM, Gargiulo S, Rotunno E, Olaya JC, Kaminer I, Grillo V, de Abajo FJG, Carbone F, Vanacore GM. Ultrafast Transverse Modulation of Free Electrons by Interaction with Shaped Optical Fields. ACS Photonics 2022; 9:3215-3224. [PMID: 36281329 PMCID: PMC9585634 DOI: 10.1021/acsphotonics.2c00850] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Indexed: 05/13/2023]
Abstract
Spatiotemporal electron-beam shaping is a bold frontier of electron microscopy. Over the past decade, shaping methods evolved from static phase plates to low-speed electrostatic and magnetostatic displays. Recently, a swift change of paradigm utilizing light to control free electrons has emerged. Here, we experimentally demonstrate arbitrary transverse modulation of electron beams without complicated electron-optics elements or material nanostructures, but rather using shaped light beams. On-demand spatial modulation of electron wavepackets is obtained via inelastic interaction with transversely shaped ultrafast light fields controlled by an external spatial light modulator. We illustrate this method for the cases of Hermite-Gaussian and Laguerre-Gaussian modulation and discuss their use in enhancing microscope sensitivity. Our approach dramatically widens the range of patterns that can be imprinted on the electron profile and greatly facilitates tailored electron-beam shaping.
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Affiliation(s)
- Ivan Madan
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Veronica Leccese
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Adam Mazur
- HOLOEYE
Photonics AG, Volmerstrasse 1, 12489 Berlin, Germany
| | - Francesco Barantani
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
- Department
of Quantum Matter Physics, University of
Geneva, 1211 Geneva, Switzerland
| | - Thomas LaGrange
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Alexey Sapozhnik
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Phoebe M. Tengdin
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Simone Gargiulo
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Enzo Rotunno
- Centro
S3, Istituto di Nanoscienze-CNR, 41125 Modena, Italy
| | | | - Ido Kaminer
- Department
of Electrical and Computer Engineering, Technion, Haifa 32000, Israel
| | | | - 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
| | - Fabrizio Carbone
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Giovanni Maria Vanacore
- Department
of Materials Science, University of Milano-Bicocca, Via Cozzi 55, 20126 Milano, Italy
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12
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Lorenzi R, Golubev NV, Ignat'eva ES, Sigaev VN, Ferrara C, Acciarri M, Vanacore GM, Paleari A. Defect-assisted photocatalytic activity of glass-embedded gallium oxide nanocrystals. J Colloid Interface Sci 2022; 608:2830-2838. [PMID: 34794807 DOI: 10.1016/j.jcis.2021.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/22/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
The use of glassceramics in photocatalysis is an attractive option for the realization of smart optical fibers and self-cleaning windows. Here we present the photocatalytic activity of germanosilicate glasses embedding Ga2O3 nanocrystals prepared by batch melting and glass heat treatment. The powdered material is used for UV-assisted degradation of rhodamine in water. The kinetics show changes after repeated experiments. In the first cycle, the apparent rate is governed by a second-order reaction with a Gaussian-like shape, whereas the second cycle follows a first-order reaction. The modification appears to be correlated with perturbations in the defect population. Photoluminescence has been used to monitor the evolution of such defects. Kinetic data on photoreactions and defect formation have been modelled in a combined frame in which the defect concentration determines the photocatalytic activity. The results prove the photocatalytic ability of the studied glassceramics. Moreover, the general validity of the kinetic model can be of interest for other systems in which the photocatalytic response depends on photoreactive species concentration.
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Affiliation(s)
- Roberto Lorenzi
- Department of Materials Science, University of Milano-Bicocca, via Cozzi 55, 20125 Milano, Italy.
| | - Nikita V Golubev
- P.D. Sarkisov International Laboratory of Glass-based Functional Materials, Mendeleev University of Chemical Technology of Russia, Miusskaya Square 9, 125047 Moscow, Russia
| | - Elena S Ignat'eva
- P.D. Sarkisov International Laboratory of Glass-based Functional Materials, Mendeleev University of Chemical Technology of Russia, Miusskaya Square 9, 125047 Moscow, Russia
| | - Vladimir N Sigaev
- P.D. Sarkisov International Laboratory of Glass-based Functional Materials, Mendeleev University of Chemical Technology of Russia, Miusskaya Square 9, 125047 Moscow, Russia
| | - Chiara Ferrara
- Department of Materials Science, University of Milano-Bicocca, via Cozzi 55, 20125 Milano, Italy
| | - Maurizio Acciarri
- Department of Materials Science, University of Milano-Bicocca, via Cozzi 55, 20125 Milano, Italy
| | - Giovanni Maria Vanacore
- Department of Materials Science, University of Milano-Bicocca, via Cozzi 55, 20125 Milano, Italy
| | - Alberto Paleari
- Department of Materials Science, University of Milano-Bicocca, via Cozzi 55, 20125 Milano, Italy
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13
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Vanacore GM, Chrastina D, Scalise E, Barbisan L, Ballabio A, Mauceri M, La Via F, Capitani G, Crippa D, Marzegalli A, Bergamaschini R, Miglio L. Nanostructured 3C-SiC on Si by a network of (111) platelets: a fully textured film generated by intrinsic growth anisotropy. Phys Chem Chem Phys 2022; 24:24487-24494. [DOI: 10.1039/d2cp03250c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper we address the unique nature of fully textured, high surface-to-volume 3C-SiC films, as produced by intrinsic growth anisotropy, in turn generated by the high velocity of the...
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14
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Ferrara C, Gentile A, Marchionna S, Quinzeni I, Fracchia M, Ghigna P, Pollastri S, Ritter C, Vanacore GM, Ruffo R. The Missing Piece: The Structure of the Ti 3C 2T x MXene and Its Behavior as Negative Electrode in Sodium Ion Batteries. Nano Lett 2021; 21:8290-8297. [PMID: 34553949 PMCID: PMC8517972 DOI: 10.1021/acs.nanolett.1c02809] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/14/2021] [Indexed: 06/13/2023]
Abstract
The most common MXene composition Ti3C2Tx (T = F, O) shows outstanding stability as anode for sodium ion batteries (100% of capacity retention after 530 cycles with charge efficiency >99.7%). However, the reversibility of the intercalation/deintercalation process is strongly affected by the synthesis parameters determining, in turn, significant differences in the material structure. This study proposes a new approach to identify the crystal features influencing the performances, using a structural model built with a multitechnique approach that allows exploring the short-range order of the lamella. The model is then used to determine the long-range order by inserting defective elements into the structure. With this strategy it is possible to fit the MXene diffraction patterns, obtain the structural parameters including the stoichiometric composition of the terminations (neutron data), and quantify the structural disorder which can be used to discriminate the phases with the best electrochemical properties.
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Affiliation(s)
- Chiara Ferrara
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano Bicocca, via Cozzi 55, 20125 Milano, Italy
- National
Reference Center for Electrochemical Energy Storage (GISEL)- Consorzio Interuniversitario Nazionale per la Scienza
e Tecnologia dei Materiali (INSTM), via Giusti 9, 50121 Firenze, Italy
| | - Antonio Gentile
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano Bicocca, via Cozzi 55, 20125 Milano, Italy
| | - Stefano Marchionna
- Ricerca
sul Sistema Energetico - RSE S.p.A., Via R. Rubattino 54, 20134 Milano, Italy
| | - Irene Quinzeni
- Ricerca
sul Sistema Energetico - RSE S.p.A., Via R. Rubattino 54, 20134 Milano, Italy
| | - Martina Fracchia
- Dipartimento
di Chimica, Università degli Studi
di Pavia, via Taramelli 12, 27100, Pavia, Italy
| | - Paolo Ghigna
- Dipartimento
di Chimica, Università degli Studi
di Pavia, via Taramelli 12, 27100, Pavia, Italy
- INSTM,
Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali, via Giusti 9, I-50121 Firenze, Italy
| | | | - Clemens Ritter
- Institut
Laue-Langevin, 71 avenue
des Martyrs CS 20156, 38042 Grenoble, Cedex 9, France
| | - Giovanni Maria Vanacore
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano Bicocca, via Cozzi 55, 20125 Milano, Italy
| | - Riccardo Ruffo
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano Bicocca, via Cozzi 55, 20125 Milano, Italy
- National
Reference Center for Electrochemical Energy Storage (GISEL)- Consorzio Interuniversitario Nazionale per la Scienza
e Tecnologia dei Materiali (INSTM), via Giusti 9, 50121 Firenze, Italy
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15
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Vanacore GM, Berruto G, Madan I, Pomarico E, Biagioni P, Lamb RJ, McGrouther D, Reinhardt O, Kaminer I, Barwick B, Larocque H, Grillo V, Karimi E, García de Abajo FJ, Carbone F. Ultrafast generation and control of an electron vortex beam via chiral plasmonic near fields. Nat Mater 2019; 18:573-579. [PMID: 31061485 DOI: 10.1038/s41563-019-0336-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 03/07/2019] [Indexed: 05/27/2023]
Abstract
Vortex-carrying matter waves, such as chiral electron beams, are of significant interest in both applied and fundamental science. Continuous-wave electron vortex beams are commonly prepared via passive phase masks imprinting a transverse phase modulation on the electron's wavefunction. Here, we show that femtosecond chiral plasmonic near fields enable the generation and dynamic control on the ultrafast timescale of an electron vortex beam. The vortex structure of the resulting electron wavepacket is probed in both real and reciprocal space using ultrafast transmission electron microscopy. This method offers a high degree of scalability to small length scales and a highly efficient manipulation of the electron vorticity with attosecond precision. Besides the direct implications in the investigation of nanoscale ultrafast processes in which chirality plays a major role, we further discuss the perspectives of using this technique to shape the wavefunction of charged composite particles, such as protons, and how it can be used to probe their internal structure.
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Affiliation(s)
- G M Vanacore
- Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
| | - G Berruto
- Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - I Madan
- Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - E Pomarico
- Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - P Biagioni
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - R J Lamb
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, UK
| | - D McGrouther
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, UK
| | - O Reinhardt
- Faculty of Electrical Engineering and Solid State Institute, Technion, Haifa, Israel
| | - I Kaminer
- Faculty of Electrical Engineering and Solid State Institute, Technion, Haifa, Israel
| | | | - H Larocque
- Department of Physics, University of Ottawa, Ottawa, Ontario, Canada
| | - V Grillo
- CNR-Istituto Nanoscienze, Centro S3, Modena, Italy
| | - E Karimi
- Department of Physics, University of Ottawa, Ottawa, Ontario, Canada
| | - F J García de Abajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - F Carbone
- Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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16
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Berruto G, Madan I, Murooka Y, Vanacore GM, Pomarico E, Rajeswari J, Lamb R, Huang P, Kruchkov AJ, Togawa Y, LaGrange T, McGrouther D, Rønnow HM, Carbone F. Laser-Induced Skyrmion Writing and Erasing in an Ultrafast Cryo-Lorentz Transmission Electron Microscope. Phys Rev Lett 2018; 120:117201. [PMID: 29601740 DOI: 10.1103/physrevlett.120.117201] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Indexed: 05/27/2023]
Abstract
We demonstrate that light-induced heat pulses of different duration and energy can write Skyrmions in a broad range of temperatures and magnetic field in FeGe. Using a combination of camera-rate and pump-probe cryo-Lorentz transmission electron microscopy, we directly resolve the spatiotemporal evolution of the magnetization ensuing optical excitation. The Skyrmion lattice was found to maintain its structural properties during the laser-induced demagnetization, and its recovery to the initial state happened in the sub-μs to μs range, depending on the cooling rate of the system.
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Affiliation(s)
- G Berruto
- Institute of Physics, LUMES, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - I Madan
- Institute of Physics, LUMES, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Y Murooka
- Institute of Physics, LUMES, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - G M Vanacore
- Institute of Physics, LUMES, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - E Pomarico
- Institute of Physics, LUMES, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - J Rajeswari
- Institute of Physics, LUMES, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - R Lamb
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - P Huang
- Institute of Physics, LUMES, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
- Institute of Physics, LQM, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - A J Kruchkov
- Institute of Physics, LQM, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Y Togawa
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Osaka Prefecture University, 1-2 Gakuencho, Sakai, Osaka 599-8570, Japan
- Chirality Research Center (CResCent), Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - T LaGrange
- Interdisciplinary Centre for Electron Microscopy, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - D McGrouther
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H M Rønnow
- Institute of Physics, LQM, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - F Carbone
- Institute of Physics, LUMES, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
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17
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Bollani M, Bietti S, Frigeri C, Chrastina D, Reyes K, Smereka P, Millunchick JM, Vanacore GM, Burghammer M, Tagliaferri A, Sanguinetti S. Ordered arrays of embedded Ga nanoparticles on patterned silicon substrates. Nanotechnology 2014; 25:205301. [PMID: 24784353 DOI: 10.1088/0957-4484/25/20/205301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We fabricate site-controlled, ordered arrays of embedded Ga nanoparticles on Si, using a combination of substrate patterning and molecular-beam epitaxial growth. The fabrication process consists of two steps. Ga droplets are initially nucleated in an ordered array of inverted pyramidal pits, and then partially crystallized by exposure to an As flux, which promotes the formation of a GaAs shell that seals the Ga nanoparticle within two semiconductor layers. The nanoparticle formation process has been investigated through a combination of extensive chemical and structural characterization and theoretical kinetic Monte Carlo simulations.
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Affiliation(s)
- M Bollani
- CNR-IFN, L-NESS, via Anzani 42, I-22100 Como, Italy
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18
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Vanacore GM, Zani M, Bollani M, Bonera E, Nicotra G, Osmond J, Capellini G, Isella G, Tagliaferri A. Monitoring the kinetic evolution of self-assembled SiGe islands grown by Ge surface thermal diffusion from a local source. Nanotechnology 2014; 25:135606. [PMID: 24594569 DOI: 10.1088/0957-4484/25/13/135606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this paper we experimentally study the growth of self-assembled SiGe islands formed on Si(001) by exploiting the thermally activated surface diffusion of Ge atoms from a local Ge source stripe in the temperature range 600-700 °C. This new growth strategy allows us to vary continuously the Ge coverage from 8 to 0 monolayers as the distance from the source increases, and thus enables the investigation of the island growth over a wide range of dynamical regimes at the same time, providing a unique birds eye view of the factors governing the growth process and the dominant mechanism for the mass collection by a critical nucleus. Our results give experimental evidence that the nucleation process evolves within a diffusion limited regime. At a given annealing temperature, we find that the nucleation density depends only on the kinetics of the Ge surface diffusion resulting in a universal scaling distribution depending only on the Ge coverage. An analytical model is able to reproduce quantitatively the trend of the island density. Following the nucleation, the growth process appears to be driven mainly by short-range interactions between an island and the atoms diffusing within its vicinities. The islands volume distribution is, in fact, well described in the whole range of parameters by the Mulheran's capture zone model. The complex growth mechanism leads to a strong intermixing of Si and Ge within the island volume. Our growth strategy allows us to directly investigate the correlation between the Si incorporation and the Ge coverage in the same experimental conditions: higher intermixing is found for lower Ge coverage. This confirms that, besides the Ge gathering from the surface, also the Si incorporation from the substrate is driven by the diffusion kinetics, thus imposing a strict constraint on the initial Ge coverage, its diffusion properties and the final island volume.
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Affiliation(s)
- G M Vanacore
- CNISM-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
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Chrastina D, Vanacore GM, Bollani M, Boye P, Schöder S, Burghammer M, Sordan R, Isella G, Zani M, Tagliaferri A. Patterning-induced strain relief in single lithographic SiGe nanostructures studied by nanobeam x-ray diffraction. Nanotechnology 2012; 23:155702. [PMID: 22456306 DOI: 10.1088/0957-4484/23/15/155702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The continued downscaling in SiGe heterostructures is approaching the point at which lateral confinement leads to a uniaxial strain state, giving high enhancements of the charge carrier mobility. Investigation of the strain relaxation as induced by the patterning of a continuous SiGe layer is thus of scientific and technological importance. In the present work, the strain in single lithographically defined low-dimensional SiGe structures has been directly mapped via nanobeam x-ray diffraction. We found that the nanopatterning is able to induce an anisotropic strain relaxation, leading to a conversion of the strain state from biaxial to uniaxial. Its origin is fully compatible with a pure elastic deformation of the crystal lattice without involving plastic relaxation by injection of misfit dislocations.
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Affiliation(s)
- D Chrastina
- CNISM and L-NESS, Dipartimento di Fisica del Politecnico di Milano, Polo Regionale di Como, via Anzani 42, I-22100 Como, Italy
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