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307 results on '"Technische Physik"'

1. Ferndetektion von schädlichen Pilzen im Weinbau durch Laserinduzierte Fluoreszenz - Weiterentwicklung des VinoLAS® Systems

Author

Deutsches Zentrum für Luft und Raumfahrt. Institut für Technische Physik, Ellingen, Elias, Deutsches Zentrum für Luft und Raumfahrt. Institut für Technische Physik, and Ellingen, Elias

Abstract

Der Befall mit schädlichen Pilzen führt im Weinbau zu Ertragseinbusen sowie zu ökonomischen und ökologischen Belastungen durch den präventiven Einsatz von Fungiziden. Diese könnten durch eine Früherkennung des Befalls verringert werden. Das Projekt vinoLAS® soll die kontaktlose Früherkennung des falschen Mehltaus, einer wichtigen schädlichen Pilzart im Weinbau, ermöglichen. Dabei sollen Methoden der laserinduzierten Fluoreszenzspektroskopie verwendet werden. In dieser Arbeit wird ein Detektionsmodul zur Analyse des laserinduziertem Fluoreszenzlichts in vier spektralen Kanälen entwickelt. Die Anforderungen an das Detektionsmodul werden festgelegt und die Entwicklung erläutert. Das System lässt sich in einen optischen und elektronischen Aufbau teilen. Das Verhalten des elektronische Aufbaus wird anhand umfangreicher Messungen bestimmt und mit den Anforderungen verglichen. Es wird mit dem optischen Aufbau zu einem Gesamtsystem kombiniert. Mit diesem werden Messungen im vinoLAS® Laboraufbau durchgeführt, welche zur Verifikation mit einer Referenzmessung verglichen werden. Die Messungen zum elektronischen Aufbau zeigen, dass alle gestellten Anforderungen erfüllt und teilweise übertroffen werden. Das entstandene Gated-Integrator System ist mit einem, deutlich teureren, kommerziellen Gated-Integrator vergleichbar, bietet dabei aber doppelt so viele Kanäle und ein 44% geringeres Rauschen. Mit der Diskussion der Messdaten werden außerdem Ansätze vorgestellt, die eine kostengünstige weiter Verbesserung des elektronischen Systems ermöglichen. Die Messungen mit dem Gesamtsystem zeigen eine qualitative Übereinstimmung mit der Referenzmessung, es sind jedoch noch quantitative Abweichungen vorhanden, die weiter untersucht werden müssen. Außerdem zeigt sich, dass die Qualität der Messdaten durch eine Schwankung der Laserfrequenz stark eingeschränkt wird. Eine leicht implementierbare und kostengünstige Lösung für dieses Problem wird jedoch vorgestellt. Nach Umsetzung der beiden Verb

Published
2022

8. Nahfeldcharakterisierung von Nahfeldsonden : Abschlußbericht des BMBF-Projekts 13N7691 ; Laufzeit des Vorhabens: 1.10.1999 - 31.12.2002

Author

WITEC Wissenschaftliche Instrumente Und Technologie GmbH, Ulm and Universität Kassel, Institut Für Technische Physik

Subjects
Condensed Matter::Materials Science, genetic structures, eye diseases
Abstract

(de)Optical near-field microscopy, near-field probes, calibration structures for near-field microscopy, ill., graphs

Published
2003
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9. Ultradünne funktionale Schichten zur Herstellung von Cantilever-basierten Sensoren : Schlußbericht zum Pilotprojekt ; Laufzeit des Vorhabens: 01.08.2001 - 31.12.2003

Author

Universität Kassel, Institut Für Technische Physik

Subjects
Sensorik, MEMS, Chemistry, Chemischer Sensor, Engineering, Mehrschichtsystem, Dünnschichtsensor, Kantilever, Mikrosystemtechnik, Nanotechnologie, Polymere, Chemisches Labor, chemische Methoden
Abstract

Ill., graph. Darst

Published
2003
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10. Observation of THz Oscillations and Efficient THz Emission from Contacted Low Temperature Grown GaAs Structures

Author

ERLANGEN-NUERNBERG UNIV (GERMANY) INSTFUER TECHNISCHE PHYSIK, Steen, Christian, Tautz, Sonke, Kiesel, Peter, Dankowski, S. U., Doehler, Gottfied H., ERLANGEN-NUERNBERG UNIV (GERMANY) INSTFUER TECHNISCHE PHYSIK, Steen, Christian, Tautz, Sonke, Kiesel, Peter, Dankowski, S. U., and Doehler, Gottfied H.

Abstract

We have performed femtosecond differential transmission experiments in low temperature grown GaAs (LT-GaAs) layers under high electric fields. The fields were induced by voltages up to 60 V applied to interdigitated contacts with a few micrometer period. Up to about 10 oscillations of the field-induced transmission changes with a period of T = 2.2 Ps were detected in a structure where the high-frequency effective length of the contacts was kept short. The large amplitude of the AC component of the differential transmission signal indicated that the amplitude of the light pulse induced oscillating electric field has to be of the same order of magnitude as the applied DC field. Thus the same has to be true also for the AC voltage between the fingers. In order to test this interpretation we have performed photomixing experiments. They yield a maximum emitted rf power of about 60 nW at a beat frequency of V = 1/T = 0.44 THz, at only 10 mW of incident optical laser power. Computer simulations yield the same frequency for the contact structure considered as a microstrip patch antenna., Prepared in cooperation with GMM, VDE/VDE-Gesellschaft Mikroelektronik, Mikro- und Feinwerktechnik; ITS, Informationstechnische Gesellschaft im VDE; Technical Univ. of Denmark, Microelectronic Centret, Lyngby, Denmark; Physikalisches Institut, J.W. Goethe Universitaet, Frankfurt, Germany; Fakultaet fuer Elektrotechnik und Informatiostechnik, TU Chemnitz, Germany. This article is from the THz Conference 2000 pp59-62. This article is from ADA398789 International Conference on Terahertz Electronics (8th), Held in Darmstadt, Germany on 28-29 September 2000

Published
2000

11. Chemical Oxygen Iodine Laser Jet Generator Characterization. Quarterly Report.

Author

FRAUNHOFER-GESELLSCHAFT STUTTGART (GERMANY F R) INST FUER TECHNISCHE PHYSIK, Bohn, Willi L., FRAUNHOFER-GESELLSCHAFT STUTTGART (GERMANY F R) INST FUER TECHNISCHE PHYSIK, and Bohn, Willi L.

Abstract

This report describes the experimental and basic theoretical work that was performed for the evaluation of a jet generator simulator for a Chemical Oxygen Iodine Laser (COIL) system. Chlorine gas reacts with liquid Basic Hydrogen Peroxide (BHP) in the generator to produce excited oxygen, O2(1 delta). The jet generator for a chemical oxygen iodine laser system has to provide a large reaction surface. This is accomplished in the generator by providing many small orifices through which the liquid BHP will flow and form liquid jets. The liquid jets should be as long and stable as possible to provide a maximum reaction surface. This experiment deals with a finite set of orifice diameters and lengths which allow for convenient scalability procedures in the future.

Published
1993

23. Attosecond-fast internal photoemission

Author

Takuya Higuchi, Lothar Ley, Peter Hommelhoff, Christian Heide, Jürgen Ristein, Martin Hauck, Heiko B. Weber, Lehrstuhl für Technische Physik, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Fakultät für Physik [Garching], Ludwig-Maximilians-Universität München (LMU), European Project: 712590,H2020 FET Open 'Technologies futures et émergentes',829153,PETACom(2019), and European Project: 616823,EC:FP7:ERC,ERC-2013-CoG,NEARFIELDATTO(2014)

Subjects
Materials science, Schottky barrier, Attosecond, FOS: Physical sciences, 02 engineering and technology, Electron, Applied Physics (physics.app-ph), 7. Clean energy, 01 natural sciences, law.invention, 010309 optics, law, 0103 physical sciences, Condensed Matter - Materials Science, business.industry, Graphene, Materials Science (cond-mat.mtrl-sci), Physics - Applied Physics, Photoelectric effect, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Semimetal, Electronic, Optical and Magnetic Materials, Semiconductor, Femtosecond, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business
Abstract

The photoelectric effect has a sister process relevant in optoelectronics called internal photoemission1–3. Here an electron is photoemitted from a metal into a semiconductor4,5. While the photoelectric effect takes place within less than 100 attoseconds (1 as = 10−18 seconds)6,7, the attosecond timescale has so far not been measured for internal photoemission. Based on the new method CHArge transfer time MEasurement via Laser pulse duration-dependent saturation fluEnce determinatiON—CHAMELEON—we show that the atomically thin semimetal graphene coupled to bulk silicon carbide, forming a Schottky junction, allows charge transfer times as fast as (300 ± 200) as. These results are supported by a simple quantum mechanical model simulation. With the obtained cut-off bandwidth of 3.3 PHz (1 PHz = 1015 Hz) for the charge transfer rate, this semimetal/semiconductor interface represents a functional solid-state interface offering the speed and design space required for future light-wave signal processing. Femtosecond laser pulses are sent to a graphene/SiC interface to investigate photoinduced charge transfer from graphene to SiC. A charge transfer time of 300 attoseconds is obtained via laser-pulse-duration-dependent saturation fluence determination.

Published
2020

24. Production and processing of graphene and related materials

Author

Backes, Abdelkader, A.M., Alonso, Andrieux-Ledier, Arenal, Azpeitia, Balakrishnan, Banszerus, Barjon, Bartali, Bellani, Berger, Ortega, M.M.B., Bernard, Beton, P.H., Beyer, Bianco, B?ggild, Bonaccorso, Barin, G.B., Botas, Bueno, R.A., Carriazo, Castellanos-Gomez, Christian, Ciesielski, Ciuk, Cole, M.T., Coleman, Coletti, Crema, Cun, Dasler, De Fazio, D?ez, Drieschner, Duesberg, G.S., Fasel, Feng, Fina, Forti, Galiotis, Garberoglio, Garc?a, J.M., Garrido, J.A., Gibertini, G?lzh?user, G?mez, Greber, Hauke, Hemmi, Hernandez-Rodriguez, Hirsch, Hodge, S.A., Huttel, Jepsen, P.U., Jimenez, Kaiser, Kaplas, Kim, Kis, Papagelis, Kostarelos, Krajewska, Lee, Lipsanen, Liscio, Lohe, M.R., Loiseau, Lombardi, L?pez, M.F., Martin, Mart?n, Mart?nez, Martin-Gago, J.I., Marzari, Mayoral, McManus, Melucci, M?ndez, Merino, Meyer, A.P., Miniussi, Miseikis, Mishra, Morandi, Munuera, Mu?oz, Nolan, Ortolani, Ott, A.K., Palacio, Palermo, Parthenios, Pasternak, Patane, Prato, Prevost, Prudkovskiy, Pugno, Rojo, Rossi, Ruffieux, Samor?, Schu?, Setijadi, Seyller, Speranza, Stampfer, Stenger, Strupinski, Svirko, Taioli, Teo, K.B.K., Testi, Tomarchio, Tortello, Treossi, Turchanin, Vazquez, Villaro, Whelan, P.R., Xia, Yakimova, Yang, Yazdi, G.R., Yim, Yoon, Zhang, Zhuang, Colombo, Ferrari, A.C., Garcia-Hernandez, European Commission, García-Hernández, M., Apollo - University of Cambridge Repository, Heidelberg University, University of Cambridge, Universidad Autónoma de Madrid, Université Paris-Saclay, Aragonese Foundation for Research & Development, CSIC, University of Nottingham, RWTH Aachen University, Université de Versailles Saint-Quentin-en-Yvelines, Bruno Kessler Foundation, Italian Institute of Technology, Université Grenoble Alpes, Technische Universität Dresden, Polytechnic University of Turin, University of Zurich, Bielefeld University, Université de Strasbourg, Technical University of Denmark, Swiss Federal Laboratories for Materials Science and Technology, CIC energigune, National Research Council of Italy, Institute of Electronic Materials Technology, University of Bath, Trinity College Dublin, Friedrich-Alexander University Erlangen-Nürnberg, Technical University of Munich, Universität der Bundeswehr München, University of Patras, CSIC - Institute of Micro and Nanotechnology, Catalan Institute of Nanoscience and Nanotechnology, Swiss Federal Institute of Technology Lausanne, Avanzare S.L. Technological Innovation, Ulm University, University of Eastern Finland, Institute of Chemical Engineering and High Temperature Chemical Processes, University of Manchester, Polish Academy of Sciences, Department of Electronics and Nanoengineering, University of Castilla-La Mancha, University of Zaragoza, Groupo Antolin I+D+I, Warsaw University of Technology, Ikerbasque Basque Foundation for Science, BEC-INFM, Chemnitz University of Technology, Charles University, Buckingway Business Park, Friedrich Schiller University Jena, Interquimica, Linköping University, University of Texas at Dallas, Aalto-yliopisto, Aalto University, Backes, C., Abdelkader, A. M., Alonso, C., Andrieux-Ledier, A., Arenal, R., Azpeitia, J., Balakrishnan, N., Banszerus, L., Barjon, J., Bartali, R., Bellani, S., Berger, C., Berger, R., Ortega, M. M. B., Bernard, C., Beton, P. H., Beyer, A., Bianco, A., Boggild, P., Bonaccorso, F., Barin, G. B., Botas, C., Bueno, R. A., Carriazo, D., Castellanos-Gomez, A., Christian, M., Ciesielski, A., Ciuk, T., Cole, M. T., Coleman, J., Coletti, C., Crema, L., Cun, H., Dasler, D., De Fazio, D., Diez, N., Drieschner, S., Duesberg, G. S., Fasel, R., Feng, X., Fina, A., Forti, S., Galiotis, C., Garberoglio, G., Garcia, J. M., Garrido, J. A., Gibertini, M., Golzhauser, A., Gomez, J., Greber, T., Hauke, F., Hemmi, A., Hernandez-Rodriguez, I., Hirsch, A., Hodge, S. A., Huttel, Y., Jepsen, P. U., Jimenez, I., Kaiser, U., Kaplas, T., Kim, H., Kis, A., Papagelis, K., Kostarelos, K., Krajewska, A., Lee, K., Li, C., Lipsanen, H., Liscio, A., Lohe, M. R., Loiseau, A., Lombardi, L., Lopez, M. F., Martin, O., Martin, C., Martinez, L., Martin-Gago, J. A., Martinez, J. I., Marzari, N., Mayoral, A., Mcmanus, J., Melucci, M., Mendez, J., Merino, C., Merino, P., Meyer, A. P., Miniussi, E., Miseikis, V., Mishra, N., Morandi, V., Munuera, C., Munoz, R., Nolan, H., Ortolani, L., Ott, A. K., Palacio, I., Palermo, V., Parthenios, J., Pasternak, I., Patane, A., Prato, M., Prevost, H., Prudkovskiy, V., Pugno, N., Rojo, T., Rossi, A., Ruffieux, P., Samori, P., Schue, L., Setijadi, E., Seyller, T., Speranza, G., Stampfer, C., Stenger, I., Strupinski, W., Svirko, Y., Taioli, S., Teo, K. B. K., Testi, M., Tomarchio, F., Tortello, M., Treossi, E., Turchanin, A., Vazquez, E., Villaro, E., Whelan, P. R., Xia, Z., Yakimova, R., Yang, S., Yazdi, G. R., Yim, C., Yoon, D., Zhang, X., Zhuang, X., Colombo, L., Ferrari, A. C., Garcia-Hernandez, M., Physikalisch-Chemisches Institut [Heidelberg] (PCI), Universität Heidelberg [Heidelberg] = Heidelberg University, Centre for Research on Adaptive Nanostructures and Nanodevices and Advanced Materials and BioEngineering Research (CRANN-AMBER), Cambridge Graphene Centre (Cambridge, UK), DPHY, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Instituto de Nanociencia de Aragón [Saragoza, España] (INA), University of Zaragoza - Universidad de Zaragoza [Zaragoza], Instituto de Ciencia de Materiales de Aragón [Saragoza, España] (ICMA-CSIC), Materials Science Factory - ICMM [Madrid], Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), School of Physics and Astronomy [Nottingham], University of Nottingham, UK (UON), Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Fondazione Bruno Kessler [Trento, Italy] (FBK), IIT Graphene Labs, Istituto Italiano di Tecnologia (IIT), Circuits électroniques quantiques Alpes (NEEL - QuantECA), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Georgia Institute of Technology [Atlanta], Technische Universität Dresden = Dresden University of Technology (TU Dresden), Politecnico di Torino = Polytechnic of Turin (Polito), Universität Zürich [Zürich] = University of Zurich (UZH), Universität Bielefeld = Bielefeld University, Immunopathologie et chimie thérapeutique (ICT), Institut de biologie moléculaire et cellulaire (IBMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Danmarks Tekniske Universitet = Technical University of Denmark (DTU), BeDimensional Spa, Swiss Federal Laboratories for Materials Science and Technology [Thun] (EMPA), CIC ENERGIGUNE - Parque Tecnol Alava, Ikerbasque - Basque Foundation for Science, Institute for Microelectronics and Microsystems (IMM ), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institut de Science et d'ingénierie supramoléculaires (ISIS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Instytut Technologii Materiałów Elektronicznych, Department of Electronics and Electrical Engineering [Bath], University of Bath [Bath], Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Walter Schottky Institut Technische Universität München, Universität der Bundeswehr München [Neubiberg], Swiss Federal Laboratories for Materials Science and Technology [Dübendorf] (EMPA), Center for Advancing Electronics in Dresden (CFAED), European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*-FBK), IMN-Instituto de Micro y Nanotecnología (CNM-CSIC), Isaac Newton 8, PTM, 28760 Tres Cantos, Madrid, Spain, Universidad de Alicante, Institut de théorie des phénomènes physiques (EPFL), Ecole Polytechnique Fédérale de Lausanne (EPFL), Avanzare Innovacion Tecnologica S.L., Center for Nanostructured Graphene, Universität Ulm - Ulm University [Ulm, Allemagne], Electrical Engineering Institute - EPFL, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institute of Chemical Engineering Sciences - Hellas [Crete] (ICE-HT), Foundation for Research and Technology - Hellas (FORTH), Aristotle University of Thessaloniki, University of Manchester [Manchester], Polish Academy of Sciences (PAN), LEM, UMR 104, CNRS-ONERA, Université Paris-Saclay (Laboratoire d'étude des microstructures), ONERA-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Universidad de Sevilla / University of Sevilla, Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Department of Materials Science and Engineering (DMSE), Massachusetts Institute of Technology (MIT), Institute of Organic Synthesis and Photoreactivity (ISOF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Instituto de Física Fundamental [Madrid] (IFF), Istituto per la Microelettronica e i Microsistemi [Bologna] (IMM), University of Exeter, Chalmers University of Technology [Göteborg], Warsaw University of Technology [Warsaw], Laboratoire national des champs magnétiques intenses - Toulouse (LNCMI-T), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), University of Trento [Trento], School of Engineering and Materials Science [London] (SEMS), Queen Mary University of London (QMUL), Departamento de Química Inorgánica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Charles University [Prague] (CU), Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], Universidad de Castilla-La Mancha = University of Castilla-La Mancha (UCLM), University of Calgary, Department of Physics, Chemistry and Biology, Linköping University, University of Linköping [Sweden], University of Texas at Dallas [Richardson] (UT Dallas), Universität Heidelberg [Heidelberg], DPHY, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), QuantECA - Circuits électroniques quantiques Alpes, Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Technische Universität Dresden (TUD), Technical University of Denmark [Lyngby] (DTU), Consiglio Nazionale delle Ricerche (CNR), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Politecnico di Torino [Torino] (Polito), University of Patras [Patras], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), LEM, UMR 104 CNRS-ONERA, Université Paris Saclay [Châtillon], Universidad de Sevilla, École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Charles University [Prague], Universidad de Castilla-La Mancha (UCLM), Autonomous University of Madrid, Faculty of Sciences, Department of Ecology, 28049 Madrid, Spain, Agencia Aragonesa por la Investigacion y el Desarollo (ARAID), Fundacion ARAID-Gobierno de Aragón [Zaragoza, Espagne], Laboratorio de Microscopias Avanzadas, JARA-FIT, Rheinisch-Westfälische Technische Hochschule Aachen (RWTH), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Dipartimento di Scienza Applicata e Tecnologia DISAT, University of Zürich, University of Zürich [Zürich] (UZH), Physics of Supramolecular Systems (Bielefeld University), Immunologie et chimie thérapeutiques (ICT), Cancéropôle du Grand Est-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Center for Nanotechnology Innovation, @NEST, Chair of Organic Chemistry II and Joint Institute of Advanced Materials and Processes, Department of Chemistry and Biochemistry, University of Bern, University of Bern, Instituto de Micro y Nanotecnología, Univ Geneva, DQMP, 24 Quai Ernest, CH-1211 Geneva 4, Switzerland, Universität Ulm - Ulm University, Institute of Photonics (Institute of Photonics), University of Shanghai [Shanghai], Istituto per la Sintesi Organica e la Fotoreattività - ISOF (Bologne, Italie), Consiglio Nazionale delle Ricerche [Bologna] (CNR), ACM Advanced Carbon Materials (Grupo Antolin Ingenieria), INRES-Chemical Signalling, Rheinische Friedrich-Wilhelms-Universität Bonn, Carbon Bionanotechnology Laboratory (CICbiomaGUNE), Dipartimento di Scienze Farmaceutiche & INSTM UdR Trieste, Université Trieste, Department of Structural Engineering and Geotechnics, Edoardo Amaldi Foundation, Lehrstuhl für Technische Physik, Technisches Universität Chemnitz, Institute of Physical Chemistry (Firedrich Schiller University Jena), Linköping University (LIU), Department of Materials Science and Engineering (University of Texas), UAM. Departamento de Química Física Aplicada, Circuits électroniques quantiques Alpes (QuantECA), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, García-Hernández, M. [0000-0002-5987-0647], European Union (EU), and Horizon 2020

Subjects
Inks of layered materials, Growth of layered material, Materialkemi, 02 engineering and technology, Chemical vapor deposition, Q1, 01 natural sciences, materials, law.invention, Characterization of layered materials, Functionalization of layered materials, Growth of layered materials, Processing of layered materials, Synthesis of graphene and related materials, law, 540 Chemistry, functionalization of layered, Materials Chemistry, General Materials Science, Graphite, QA, QC, growth of, SYNTHESE DU GRAPHENE ET DES MATERIAUX ASSOCIES, Settore FIS/01 - Fisica Sperimentale, Processing of layered material, Química, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Exfoliation joint, ddc, Characterization of layered material, layered materials, Nanoröhre, Mechanics of Materials, processing of layered materials, inks of layered materials, characterization of layered materials, functionalization of layered materials, synthesis of graphene and related materials, growth of layered materials, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], PROCÉDURE DES MATERIAUX EN COUCHE, ddc:620, 0210 nano-technology, 51 Physical Sciences, Graphene nanoribbons, Materials science, 530 Physics, Nanotechnology, 010402 general chemistry, FONCTIONNALISATION DES MATERIAUX EN COUCHES, Monolayer, Functionalization of layered material, ddc:530, Thin film, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], Nanocomposite, Graphene, Inks of layered material, Mechanical Engineering, Física, General Chemistry, CARACTERISATION DES MATERAUX EN COUCHES, CROISSANCE DES MATERIAUX EN COUCHE, 5104 Condensed Matter Physics, 0104 chemical sciences, 7 Affordable and Clean Energy, ENCRAGE DES MATERIAUX EN COUCHE
Abstract

We present an overview of the main techniques for production and processing of graphene and related materials (GRMs), as well as the key characterization procedures. We adopt a 'hands-on' approach, providing practical details and procedures as derived from literature as well as from the authors' experience, in order to enable the reader to reproduce the results. Section I is devoted to 'bottom up' approaches, whereby individual constituents are pieced together into more complex structures. We consider graphene nanoribbons (GNRs) produced either by solution processing or by on-surface synthesis in ultra high vacuum (UHV), as well carbon nanomembranes (CNM). Production of a variety of GNRs with tailored band gaps and edge shapes is now possible. CNMs can be tuned in terms of porosity, crystallinity and electronic behaviour. Section II covers 'top down' techniques. These rely on breaking down of a layered precursor, in the graphene case usually natural crystals like graphite or artificially synthesized materials, such as highly oriented pyrolythic graphite, monolayers or few layers (FL) flakes. The main focus of this section is on various exfoliation techniques in a liquid media, either intercalation or liquid phase exfoliation (LPE). The choice of precursor, exfoliation method, medium as well as the control of parameters such as time or temperature are crucial. A definite choice of parameters and conditions yields a particular material with specific properties that makes it more suitable for a targeted application. We cover protocols for the graphitic precursors to graphene oxide (GO). This is an important material for a range of applications in biomedicine, energy storage, nanocomposites, etc. Hummers' and modified Hummers' methods are used to make GO that subsequently can be reduced to obtain reduced graphene oxide (RGO) with a variety of strategies. GO flakes are also employed to prepare three-dimensional (3d) low density structures, such as sponges, foams, hydro- or aerogels. The assembly of flakes into 3d structures can provide improved mechanical properties. Aerogels with a highly open structure, with interconnected hierarchical pores, can enhance the accessibility to the whole surface area, as relevant for a number of applications, such as energy storage. The main recipes to yield graphite intercalation compounds (GICs) are also discussed. GICs are suitable precursors for covalent functionalization of graphene, but can also be used for the synthesis of uncharged graphene in solution. Degradation of the molecules intercalated in GICs can be triggered by high temperature treatment or microwave irradiation, creating a gas pressure surge in graphite and exfoliation. Electrochemical exfoliation by applying a voltage in an electrolyte to a graphite electrode can be tuned by varying precursors, electrolytes and potential. Graphite electrodes can be either negatively or positively intercalated to obtain GICs that are subsequently exfoliated. We also discuss the materials that can be amenable to exfoliation, by employing a theoretical data-mining approach. The exfoliation of LMs usually results in a heterogeneous dispersion of flakes with different lateral size and thickness. This is a critical bottleneck for applications, and hinders the full exploitation of GRMs produced by solution processing. The establishment of procedures to control the morphological properties of exfoliated GRMs, which also need to be industrially scalable, is one of the key needs. Section III deals with the processing of flakes. (Ultra)centrifugation techniques have thus far been the most investigated to sort GRMs following ultrasonication, shear mixing, ball milling, microfluidization, and wet-jet milling. It allows sorting by size and thickness. Inks formulated from GRM dispersions can be printed using a number of processes, from inkjet to screen printing. Each technique has specific rheological requirements, as well as geometrical constraints. The solvent choice is critical, not only for the GRM stability, but also in terms of optimizing printing on different substrates, such as glass, Si, plastic, paper, etc, all with different surface energies. Chemical modifications of such substrates is also a key step. Sections IV–VII are devoted to the growth of GRMs on various substrates and their processing after growth to place them on the surface of choice for specific applications. The substrate for graphene growth is a key determinant of the nature and quality of the resultant film. The lattice mismatch between graphene and substrate influences the resulting crystallinity. Growth on insulators, such as SiO2, typically results in films with small crystallites, whereas growth on the close-packed surfaces of metals yields highly crystalline films. Section IV outlines the growth of graphene on SiC substrates. This satisfies the requirements for electronic applications, with well-defined graphene-substrate interface, low trapped impurities and no need for transfer. It also allows graphene structures and devices to be measured directly on the growth substrate. The flatness of the substrate results in graphene with minimal strain and ripples on large areas, allowing spectroscopies and surface science to be performed. We also discuss the surface engineering by intercalation of the resulting graphene, its integration with Si-wafers and the production of nanostructures with the desired shape, with no need for patterning. Section V deals with chemical vapour deposition (CVD) onto various transition metals and on insulators. Growth on Ni results in graphitized polycrystalline films. While the thickness of these films can be optimized by controlling the deposition parameters, such as the type of hydrocarbon precursor and temperature, it is difficult to attain single layer graphene (SLG) across large areas, owing to the simultaneous nucleation/growth and solution/precipitation mechanisms. The differing characteristics of polycrystalline Ni films facilitate the growth of graphitic layers at different rates, resulting in regions with differing numbers of graphitic layers. High-quality films can be grown on Cu. Cu is available in a variety of shapes and forms, such as foils, bulks, foams, thin films on other materials and powders, making it attractive for industrial production of large area graphene films. The push to use CVD graphene in applications has also triggered a research line for the direct growth on insulators. The quality of the resulting films is lower than possible to date on metals, but enough, in terms of transmittance and resistivity, for many applications as described in section V. Transfer technologies are the focus of section VI. CVD synthesis of graphene on metals and bottom up molecular approaches require SLG to be transferred to the final target substrates. To have technological impact, the advances in production of high-quality large-area CVD graphene must be commensurate with those on transfer and placement on the final substrates. This is a prerequisite for most applications, such as touch panels, anticorrosion coatings, transparent electrodes and gas sensors etc. New strategies have improved the transferred graphene quality, making CVD graphene a feasible option for CMOS foundries. Methods based on complete etching of the metal substrate in suitable etchants, typically iron chloride, ammonium persulfate, or hydrogen chloride although reliable, are time- and resource-consuming, with damage to graphene and production of metal and etchant residues. Electrochemical delamination in a low-concentration aqueous solution is an alternative. In this case metallic substrates can be reused. Dry transfer is less detrimental for the SLG quality, enabling a deterministic transfer. There is a large range of layered materials (LMs) beyond graphite. Only few of them have been already exfoliated and fully characterized. Section VII deals with the growth of some of these materials. Amongst them, h-BN, transition metal tri- and di-chalcogenides are of paramount importance. The growth of h-BN is at present considered essential for the development of graphene in (opto) electronic applications, as h-BN is ideal as capping layer or substrate. The interesting optical and electronic properties of TMDs also require the development of scalable methods for their production. Large scale growth using chemical/physical vapour deposition or thermal assisted conversion has been thus far limited to a small set, such as h-BN or some TMDs. Heterostructures could also be directly grown. Section VIII discusses advances in GRM functionalization. A broad range of organic molecules can be anchored to the sp 2 basal plane by reductive functionalization. Negatively charged graphene can be prepared in liquid phase (e.g. via intercalation chemistry or electrochemically) and can react with electrophiles. This can be achieved both in dispersion or on substrate. The functional groups of GO can be further derivatized. Graphene can also be noncovalently functionalized, in particular with polycyclic aromatic hydrocarbons that assemble on the sp 2 carbon network by π–π stacking. In the liquid phase, this can enhance the colloidal stability of SLG/FLG. Approaches to achieve noncovalent on-substrate functionalization are also discussed, which can chemically dope graphene. Research efforts to derivatize CNMs are also summarized, as well as novel routes to selectively address defect sites. In dispersion, edges are the most dominant defects and can be covalently modified. This enhances colloidal stability without modifying the graphene basal plane. Basal plane point defects can also be modified, passivated and healed in ultra-high vacuum. The decoration of graphene with metal nanoparticles (NPs) has also received considerable attention, as it allows to exploit synergistic effects between NPs and graphene. Decoration can be either achieved chemically or in the gas phase. All LMs, can be functionalized and we summarize emerging approaches to covalently and noncovalently functionalize MoS2 both in the liquid and on substrate. Section IX describes some of the most popular characterization techniques, ranging from optical detection to the measurement of the electronic structure. Microscopies play an important role, although macroscopic techniques are also used for the measurement of the properties of these materials and their devices. Raman spectroscopy is paramount for GRMs, while PL is more adequate for non-graphene LMs (see section IX.2). Liquid based methods result in flakes with different thicknesses and dimensions. The qualification of size and thickness can be achieved using imaging techniques, like scanning probe microscopy (SPM) or transmission electron microscopy (TEM) or spectroscopic techniques. Optical microscopy enables the detection of flakes on suitable surfaces as well as the measurement of optical properties. Characterization of exfoliated materials is essential to improve the GRM metrology for applications and quality control. For grown GRMs, SPM can be used to probe morphological properties, as well as to study growth mechanisms and quality of transfer. More generally, SPM combined with smart measurement protocols in various modes allows one to get obtain information on mechanical properties, surface potential, work functions, electrical properties, or effectiveness of functionalization. Some of the techniques described are suitable for 'in situ' characterization, and can be hosted within the growth chambers. If the diagnosis is made 'ex situ', consideration should be given to the preparation of the samples to avoid contamination. Occasionally cleaning methods have to be used prior to measurement., We acknowledge funding from the European Commission Graphene Flagship Core1 (grant agreement 696656) and Core2 (grant agreement 785219).

Published
2020

38. Effective inelastic scattering cross-sections for background analysis in HAXPES of deeply buried layers

Author

Risterucci, Paul, Renault, O., Zborowski, Charlotte, Bertrand, D., Torres, A., Rueff, J., Ceolin, D., Grenet, Geneviève, Schneider, C., Tougaard, S., Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), University of Southern Denmark (SDU), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Mécanique des Matériaux et des Structures (M2S), Sols - Matériaux - Structures, Intégrité et Durabilité (SMS-ID), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Technische Physik, Julius-Maximilians-Universität Würzburg (JMU), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark, Julius-Maximilians-Universität Würzburg [Wurtzbourg, Allemagne] (JMU), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon

Subjects
Materials science, Hard X-ray photoemission, Annealing (metallurgy), General Physics and Astronomy, Inelastic scattering cross-section, 02 engineering and technology, Inelastic scattering, 01 natural sciences, Spectral line, [SPI.MAT]Engineering Sciences [physics]/Materials, Overlayer, Optics, 0103 physical sciences, Power semiconductor device, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [PHYS]Physics [physics], 010302 applied physics, Buried interface, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, Scattering, Bilayer, Surfaces and Interfaces, General Chemistry, Photoelectric effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business, Background analysis
Abstract

International audience; Inelastic background analysis of HAXPES spectra was recently introduced as a powerful method to get access to the elemental distribution in deeply buried layers or interfaces, at depth up to 60 nm below the surface. However the accuracy of the analysis highly relies on suitable scattering cross-sections able to describe effectively the transport of photoelectrons through overlayer structures consisting of individual layers with potentially very different scattering properties. Here, we show that within Tougaard’s practical framework as implemented in the Quases-Analyze software, the photoelectron transport through thick (25–40 nm) multi-layer structures with widely different cross-sections can be reliably described with an effective cross-section in the form of a weighted sum of the individual cross-section of each layer. The high-resolution core-level analysis partly provides a guide for determining the nature of the individual cross-sections to be used. We illustrate this novel approach with the practical case of a top Al/Ti bilayer structure in an AlGaN/GaN power transistor device stack before and after sucessive annealing treatments. The analysis provides reliable insights on the Ti and Ga depth distributions up to nearly 50 nm below the surface.

Published
2017

39. Mechanisms of Manganese Oxide Electrocatalysts Degradation during Oxygen Reduction and Oxygen Evolution Reactions

Author

Frédéric Jaouen, Serhiy Cherevko, Florian Speck, Pietro Giovanni Santori, Lehrstuhl für Technische Physik, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Helmholtz Institute Erlangen Nürnberg for Renewable Energy (IEK-11), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, European Project: 721065,CREATE, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Chemistry, Oxygen evolution, 02 engineering and technology, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, 021001 nanoscience & nanotechnology, Manganese oxide, 01 natural sciences, 7. Clean energy, Oxygen reduction, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Metal, General Energy, Membrane, Chemical engineering, visual_art, visual_art.visual_art_medium, Fuel cells, Degradation (geology), Physical and Theoretical Chemistry, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

Anion-exchange membrane fuel cells and electrolyzers offer a unique opportunity of using non-noble metal electrocatalysts for catalyzing the sluggish oxygen reduction and oxygen evolution reactions...

Published
2019

40. Stability limits of Ni-based hydrogen oxidation electrocatalysts for anion exchange membrane fuel cells

Author

Michael T. Y. Paul, Florian Speck, Dario R. Dekel, Serhiy Cherevko, Elena S. Davydova, Technion - Israel Institute of Technology [Haifa], Lehrstuhl für Technische Physik, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Helmholtz Institute Erlangen Nürnberg for Renewable Energy (IEK-11), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, and European Project: 721065,CREATE

Subjects
Ion exchange, Chemistry, Hydrogen oxidation, Inorganic chemistry, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrocatalyst, 01 natural sciences, Catalysis, 0104 chemical sciences, Nickel, Membrane, Fuel cells, [CHIM]Chemical Sciences, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

Among the non-noble-metal electrocatalysts for the hydrogen oxidation reaction (HOR) in anion exchange membrane fuel cells (AEMFCs), Ni-based nanoparticles have shown the highest reported activitie...

Published
2019

41. Dissociative recombination of CH2NH2+: a crucial link with interstellar methanimine and Titan ammonia

Author

Viatcheslav Kokoouline, Chi Hong Yuen, I. F. Schneider, Cecilia Ceccarelli, Mehdi Ayouz, Nadia Balucani, School of Animal, Plant & Environmental Sciences, University of the Witwatersrand [Johannesburg] (WITS), Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Génie des Procédés et Matériaux - EA 4038 (LGPM), CentraleSupélec, Università degli Studi di Perugia (UNIPG), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Ondes et Milieux Complexes (LOMC), Centre National de la Recherche Scientifique (CNRS)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Technische Physik, Julius-Maximilians-Universität Würzburg [Wurtzbourg, Allemagne] (JMU), Department of Physics [Orlando] (UCF | Physics), University of Central Florida [Orlando] (UCF), Dipartimento di Chimica [Perugia], Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan)

Subjects
Astrochemistry, molecular data, Electron, 01 natural sciences, 7. Clean energy, Molecular physics, Ion, Nebulae, symbols.namesake, [SPI]Engineering Sciences [physics], 0103 physical sciences, Atmosphere of Titan, 010303 astronomy & astrophysics, Dissociative recombination, ComputingMilieux_MISCELLANEOUS, Physics, planets and satellites: atmospheres, [PHYS]Physics [physics], 010308 nuclear & particles physics, Star formation, astrochemistry, scattering, Astronomy and Astrophysics, ISM: molecules, molecular processes, 13. Climate action, Space and Planetary Science, astrochimica, symbols, Astrophysics::Earth and Planetary Astrophysics, Titan (rocket family), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Excitation
Abstract

International audience; Cross sections for dissociative recombination (DR) and vibrational excitation of the CH2NH + 2 ion in collisions with electrons are determined theoretically. The corresponding thermally averaged rate coefficients are computed and fitted to analytical formulas. The obtained DR rate coefficient is significantly smaller than the values recently employed in the photochemical models of the upper atmosphere of Titan, which has an important impact on the models that aim to reproduce the Titan ammonia abundance. On the other hand, the present results support the astrophysical models reproducing the abundance of the methanimine (CH2NH) detected in massive star formation regions. In these models, the CH2NH + 2 DR is a major route of formation of this molecule with a high prebiotic potential.

Published
2019

42. Towards polariton blockade of confined exciton–polaritons

Author

Christian Schneider, Thomas Fink, Atac Imamoglu, Sven Höfling, Aymeric Delteil, Anne Schade, Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Institute of Quantum Electronics [ETH Zürich] (IQE), Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Technische Physik, Julius-Maximilians-Universität Würzburg [Wurtzbourg, Allemagne] (JMU), University of St Andrews. Condensed Matter Physics, and University of St Andrews. School of Physics and Astronomy

Subjects
Quantum decoherence, Photon, Chemistry(all), NDAS, Physics::Optics, 02 engineering and technology, Exciton-polaritons, 010402 general chemistry, 01 natural sciences, Materials Science(all), [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Quantum mechanics, Polariton, General Materials Science, Quantum, R2C, QC, Quantum well, Physics, Condensed Matter::Quantum Gases, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, Condensed Matter::Other, Mechanical Engineering, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, QC Physics, Mechanics of Materials, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], Dissipative system, Photonics, BDC, 0210 nano-technology, business
Abstract

Nature Materials, 18 (3), ISSN:1476-1122, ISSN:1476-4660

Published
2019

43. Optical valley Hall effect for highly valley-coherent exciton-polaritons in an atomically thin semiconductor

Author

Nils Lundt, Evgeny Sedov, Ying Qin, Martin Klaas, Johannes Beierlein, Ł. Dusanowski, Maxime Richard, Alexey Kavokin, Mikhail M. Glazov, Sebastian Klembt, Christian Schneider, Sven Höfling, Sefaattin Tongay, Petr Stepanov, University of St Andrews. Condensed Matter Physics, University of St Andrews. School of Physics and Astronomy, University of Würzburg = Universität Würzburg, Stoletov’s Vladimir State University (VSU), Nanophysique et Semiconducteurs (NPSC), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), A.F. Ioffe Physical-Technical Institute, Russian Academy of Sciences [Moscow] (RAS), Arizona State University [Tempe] (ASU), Westlake University [Zhejiang], Technische Physik, and Julius-Maximilians-Universität Würzburg [Wurtzbourg, Allemagne] (JMU)

Subjects
Photon, [PHYS.COND.GAS]Physics [physics]/Condensed Matter [cond-mat]/Quantum Gases [cond-mat.quant-gas], Exciton, Biomedical Engineering, NDAS, Physics::Optics, FOS: Physical sciences, Bioengineering, 02 engineering and technology, Exciton-polaritons, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Photonic metamaterial, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Hall effect, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Polariton, General Materials Science, Electrical and Electronic Engineering, ComputingMilieux_MISCELLANEOUS, QC, Physics, Condensed matter physics, Condensed Matter - Mesoscale and Nanoscale Physics, business.industry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Semiconductor, QC Physics, Quantum Gases (cond-mat.quant-gas), Photonics, 0210 nano-technology, business, Condensed Matter - Quantum Gases
Abstract

C.S. acknowledges support by the ERC (Project unLiMIt-2D). The Würzburg group acknowledges support by the State of Bavaria. A.V.K. acknowledges the support from Westlake University (Project No. 041020100118). E.S. acknowledges support from the President of the Russian Federation for state support of young Russian scientists Grant No. MK-2839.2019.2 and the RFBR Grant No. 17-52-10006. S.K. acknowledges support by the EU (Marie Curie Project TOPOPOLIS). Q.Y. and S.T. acknowledge funding from NSF DMR-1838443 and DMR-1552220. M.M.G. acknowledges partial support from RFBR Project 17-02-00383. Spin–orbit coupling is a fundamental mechanism that connects the spin of a charge carrier with its momentum. In the optical domain, an analogous synthetic spin–orbit coupling is accessible by engineering optical anisotropies in photonic materials. Both yield the possibility of creating devices that directly harness spin and polarization as information carriers. Atomically thin transition metal dichalcogenides promise intrinsic spin-valley Hall features for free carriers, excitons and photons. Here we demonstrate spin- and valley-selective propagation of exciton-polaritons in a monolayer of MoSe2 that is strongly coupled to a microcavity photon mode. In a wire-like device we trace the flow and helicity of exciton-polaritons expanding along its channel. By exciting a coherent superposition of K and K′ tagged polaritons, we observe valley-selective expansion of the polariton cloud without either an external magnetic field or coherent Rayleigh scattering. The observed optical valley Hall effect occurs on a macroscopic scale, offering the potential for applications in spin-valley-locked photonic devices. Postprint Postprint

Published
2019
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44. Rabi oscillations of a quantum dot exciton coupled to acoustic phonons : coherence and population readout

Author

Wigger, Daniel, Schneider, Christian, Gerhardt, Stefan, Kamp, Martin, Hofling, Sven, Kuhn, Tilmann, Kasprzak, Jacek, University of St Andrews. Condensed Matter Physics, University of St Andrews. School of Physics and Astronomy, Julius-Maximilians-Universität Würzburg [Wurtzbourg, Allemagne] (JMU), Technische Physik, Nanophysique et Semiconducteurs (NPSC), Institut Néel (NEEL), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
[PHYS]Physics [physics], QC Physics, Condensed Matter - Mesoscale and Nanoscale Physics, TK, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), NDAS, FOS: Physical sciences, ComputingMilieux_MISCELLANEOUS, QC, Physics - Optics, Optics (physics.optics), TK Electrical engineering. Electronics Nuclear engineering
Abstract

While the advanced coherent control of qubits is now routinely carried out in low frequency (GHz) systems like single spins, it is far more challenging to achieve for two-level systems in the optical domain. This is because the latter evolve typically in the THz range, calling for tools of ultrafast, coherent, nonlinear optics. Using four-wave mixing micro-spectroscopy, we here measure the optically driven dynamics of a single exciton quantum state confined in a semiconductor quantum dot. In a combined experimental and theoretical approach, we reveal the intrinsic Rabi oscillation dynamics by monitoring both central exciton quantities, i.e., its occupation and the microscopic coherence, as resolved by the four-wave mixing technique. In the frequency domain this oscillation generates the Autler-Townes splitting of the light-exciton dressed states, directly seen in the four-wave mixing spectra. We further demonstrate that the coupling to acoustic phonons strongly influences the FWM dynamics on the picosecond timescale, because it leads to transitions between the dressed states., Comment: accepted for publication in Optica

Published
2018

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