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Shigeki Otani - One of the best experts on this subject based on the ideXlab platform.

  • Oxidation process of Mo2C(0001) studied by Photoelectron Spectroscopy
    Applied Surface Science, 2004
    Co-Authors: Kazuyuki Edamoto, Kenichi Ozawa, M Sugihara, Shigeki Otani
    Abstract:

    Oxygen adsorption on the α-Mo 2 C(0001) surface has been investigated with valence Photoelectron Spectroscopy (PES) utilizing synchrotron radiation and X-ray Photoelectron Spectroscopy (XPS). It is found that the adsorbed oxygen atoms interact both with Mo and C atoms forming an oxycarbide layer on the Mo 2 C(0 0 0 1) surface. Valence PES study shows that the oxygen adsorption induces a state around the Fermi level, which enhances the emission intensity at the Fermi edge in PES spectra.

  • Photoelectron Spectroscopy study of Mo2C(0001)
    Solid State Communications, 2001
    Co-Authors: M Sugihara, Kenichi Ozawa, Kazuyuki Edamoto, Shigeki Otani
    Abstract:

    Abstract The (0001) surface of α-Mo 2 C has been studied using low-energy electron diffraction (LEED), X-ray Photoelectron Spectroscopy and angle-resolved Photoelectron Spectroscopy. When the ion-bombarded (1 keV of Ar + ) surface is annealed at 1600 K, a C-rich MoC-like surface is formed. The surface gives a complex LEED pattern composed of (1×1) orthorhombic spots, (2×2)R15° spots, and (4/3×4/3)R5° spots. Photon energy dependence of the normal-emission spectra is measured and it is found that the spectrum in the valence band region consists of Mo 4d band, Mo 4d–C 2p hybrid band, and C 2s band. Any peaks associated with surface states are not found.

Kenichi Ozawa - One of the best experts on this subject based on the ideXlab platform.

  • Ultraviolet Photoelectron Spectroscopy
    Compendium of Surface and Interface Analysis, 2018
    Co-Authors: Kenichi Ozawa
    Abstract:

    UPS is a Photoelectron Spectroscopy technique using photons in the ultraviolet region (typically from 10 to 150 eV) as an excitation source. The technique is used to study valence electronic structures of solid surfaces, molecular orbital energies of adsorbed species and work functions of the surfaces and their changes induced by the adsorption of atoms and molecules. Shallow (low binding energy) core levels of composite atoms of the surfaces are also accessible by UPS so that the chemical state analysis is possible like X-ray Photoelectron Spectroscopy (XPS).

  • Oxidation process of Mo2C(0001) studied by Photoelectron Spectroscopy
    Applied Surface Science, 2004
    Co-Authors: Kazuyuki Edamoto, Kenichi Ozawa, M Sugihara, Shigeki Otani
    Abstract:

    Oxygen adsorption on the α-Mo 2 C(0001) surface has been investigated with valence Photoelectron Spectroscopy (PES) utilizing synchrotron radiation and X-ray Photoelectron Spectroscopy (XPS). It is found that the adsorbed oxygen atoms interact both with Mo and C atoms forming an oxycarbide layer on the Mo 2 C(0 0 0 1) surface. Valence PES study shows that the oxygen adsorption induces a state around the Fermi level, which enhances the emission intensity at the Fermi edge in PES spectra.

  • Photoelectron Spectroscopy study of Mo2C(0001)
    Solid State Communications, 2001
    Co-Authors: M Sugihara, Kenichi Ozawa, Kazuyuki Edamoto, Shigeki Otani
    Abstract:

    Abstract The (0001) surface of α-Mo 2 C has been studied using low-energy electron diffraction (LEED), X-ray Photoelectron Spectroscopy and angle-resolved Photoelectron Spectroscopy. When the ion-bombarded (1 keV of Ar + ) surface is annealed at 1600 K, a C-rich MoC-like surface is formed. The surface gives a complex LEED pattern composed of (1×1) orthorhombic spots, (2×2)R15° spots, and (4/3×4/3)R5° spots. Photon energy dependence of the normal-emission spectra is measured and it is found that the spectrum in the valence band region consists of Mo 4d band, Mo 4d–C 2p hybrid band, and C 2s band. Any peaks associated with surface states are not found.

Maria Hahlin - One of the best experts on this subject based on the ideXlab platform.

  • Probing a battery electrolyte drop with ambient pressure Photoelectron Spectroscopy
    Nature communications, 2019
    Co-Authors: Julia Maibach, Håkan Rensmo, Hans Siegbahn, Ida Källquist, Margit Andersson, Samuli Urpelainen, Kristina Edström, Maria Hahlin
    Abstract:

    Operando ambient pressure Photoelectron Spectroscopy in realistic battery environments is a key development towards probing the functionality of the electrode/electrolyte interface in lithium-ion batteries that is not possible with conventional Photoelectron Spectroscopy. Here, we present the ambient pressure Photoelectron Spectroscopy characterization of a model electrolyte based on 1M bis(trifluoromethane)sulfonimide lithium salt in propylene carbonate. For the first time, we show ambient pressure Photoelectron Spectroscopy data of propylene carbonate in the liquid phase by using solvent vapor as the stabilizing environment. This enables us to separate effects from salt and solvent, and to characterize changes in electrolyte composition as a function of probing depth. While the bulk electrolyte meets the expected composition, clear accumulation of ionic species is found at the electrolyte surface. Our results show that it is possible to measure directly complex liquids such as battery electrolytes, which is an important accomplishment towards true operando studies.

  • Photoelectron Spectroscopy for Lithium Battery Interface Studies
    Journal of The Electrochemical Society, 2015
    Co-Authors: Bertrand Philippe, Hans Siegbahn, Kristina Edström, Maria Hahlin, Torbjörn Gustafsson, Håkan Rensmo
    Abstract:

    Photoelectron Spectroscopy (PES) has become an important tool for investigating Li-ion battery materials, in particular for analyzing interfacial structures and reactions. Since the methodology was ...

Rhouhei Nakata - One of the best experts on this subject based on the ideXlab platform.

Håkan Rensmo - One of the best experts on this subject based on the ideXlab platform.

  • Probing a battery electrolyte drop with ambient pressure Photoelectron Spectroscopy
    Nature communications, 2019
    Co-Authors: Julia Maibach, Håkan Rensmo, Hans Siegbahn, Ida Källquist, Margit Andersson, Samuli Urpelainen, Kristina Edström, Maria Hahlin
    Abstract:

    Operando ambient pressure Photoelectron Spectroscopy in realistic battery environments is a key development towards probing the functionality of the electrode/electrolyte interface in lithium-ion batteries that is not possible with conventional Photoelectron Spectroscopy. Here, we present the ambient pressure Photoelectron Spectroscopy characterization of a model electrolyte based on 1M bis(trifluoromethane)sulfonimide lithium salt in propylene carbonate. For the first time, we show ambient pressure Photoelectron Spectroscopy data of propylene carbonate in the liquid phase by using solvent vapor as the stabilizing environment. This enables us to separate effects from salt and solvent, and to characterize changes in electrolyte composition as a function of probing depth. While the bulk electrolyte meets the expected composition, clear accumulation of ionic species is found at the electrolyte surface. Our results show that it is possible to measure directly complex liquids such as battery electrolytes, which is an important accomplishment towards true operando studies.

  • X-Ray Photoelectron Spectroscopy for Understanding Molecular and Hybrid Solar Cells
    Molecular Devices for Solar Energy Conversion and Storage, 2018
    Co-Authors: Ute B Cappel, Valeria Lanzilotto, Erik M. J. Johansson, Tomas Edvinsson, Håkan Rensmo
    Abstract:

    X-ray Photoelectron Spectroscopy is a powerful tool for the characterization of molecular and hybrid solar cells. This technique allows for atomic-level characterization of their components as well as for the determination of the electronic structure that governs the key conversion processes. In this chapter, we introduce the basic concepts of electronic structure in molecules and semiconducting materials followed by a description of the concepts of Photoelectron Spectroscopy and how they relate to electronic structure. Finally, we give examples of the application of Photoelectron Spectroscopy to different types of molecular and hybrid solar cell materials demonstrating the type of information that can be obtained, to gain fundamental understanding and to further develop such devices.

  • Photoelectron Spectroscopy for Lithium Battery Interface Studies
    Journal of The Electrochemical Society, 2015
    Co-Authors: Bertrand Philippe, Hans Siegbahn, Kristina Edström, Maria Hahlin, Torbjörn Gustafsson, Håkan Rensmo
    Abstract:

    Photoelectron Spectroscopy (PES) has become an important tool for investigating Li-ion battery materials, in particular for analyzing interfacial structures and reactions. Since the methodology was ...

  • Photoelectron Spectroscopy for Chemical Analysis.
    Chimia, 2015
    Co-Authors: Håkan Rensmo, Hans Siegbahn
    Abstract:

    Photoelectron Spectroscopy started its modern development in the fifties based on techniques for studies of nuclear decay. Since then, Photoelectron Spectroscopy has undergone a dramatic expansion of application and is now a prime research tool in basic and applied science. This progress has been largely due to the concomitant development of photon sources, sample handling and electron energy analyzers. The present article describes some of the salient features of modern Photoelectron Spectroscopy and its applications with particular emphasis on energy relevant issues.