Roadmap for Photoelectron Spectroscopy
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X-Ray Photoelectron Spectroscopy (XPS)
XX--RayRay PhotoelectronPhotoelectron SpectroscopySpectroscopy (XPS)(XPS) Louis Scudiero http://www.wsu.edu/~scudiero; 5-2669 Electron Spectroscopy for Chemical Analysis (ESCA) • The basic principle of the photoelectric effect was enunciated by Einstein [1] in 1905 E = hν There is a threshold in frequency below which light, regardless of intensity, fails to eject electrons from a metallic surface. hνc > eΦm where h is the Planck constant ( 6.62 x 10-34 J s ) and ν– the frequency of the radiation • In photoelectron spectroscopy such XPS, Auger and UPS, the photon energies range from 20 -1500 eV (even higher in the case of Auger, up to 10,000eV) much greater than any typical work function values (2-5 eV). • In these techniques, the kinetic energy distribution of the emitted photoelectrons (i.e. the number of emitted electrons as a function of their kinetic energy) can be measured using any appropriate electron energy analyzer and a photoelectron spectrum can thus be recorded. [1] Eintein A. Ann. Physik 1905, 17, 132. • By using photo-ionization and energy-dispersive analysis of the emitted photoelectrons the composition and electronic state of the surface region of a sample can be studied. • Traditionally, these techniques have been subdivided according to the source of exciting radiation into : • X-ray Photoelectron Spectroscopy (XPS or ESCA) - using soft x-ray (200 - 1500 eV) radiation to examine core-levels. • Ultraviolet Photoelectron Spectroscopy (UPS) - using vacuum UV (10 - 45 eV) radiation to examine valence levels. • Auger Electron Spectroscopy (AES or SAM) – using energetic electron (1000 – 10,000 eV) to examine core-levels. • Synchrotron radiation sources have enabled high resolution studies to be carried out with radiation spanning a much wider and more complete energy range ( 5 - 5000+ eV ) but such work will remain, a very small minority of all photoelectron studies due to the expense, complexity and limited availability of such sources. -
Photoelectron Spectroscopy on Atoms, Molecules and Clusters
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 375 Photoelectron Spectroscopy on Atoms, Molecules and Clusters The Geometric and Electronic Structure Studied by Synchrotron Radiation and Lasers TORBJÖRN RANDER ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 UPPSALA ISBN 978-91-554-7047-0 2007 urn:nbn:se:uu:diva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“Och kallas därför höga bergen hos oss fjäll, av orsak att där oppå inga trän eller örter växa, utan de är glatta och bara såsom fjäll uppå en fisk” – Olof Rudbäck d. ä. -
Main Panel B
MAIN PANEL B Sub-panel 7: Earth Systems and Environmental Sciences Sub-panel 8: Chemistry Sub-panel 9: Physics Sub-panel 10: Mathematical Sciences Sub-panel 11: Computer Science and Informatics Sub-panel 12: Engineering Where required, specialist advisers have been appointed to the REF sub-panels to provide advice to the REF sub-panels on outputs in languages other than English, and / or English-language outputs in specialist areas, that the panel is otherwise unable to assess. This may include outputs containing a substantial amount of code, notation or technical terminology analogous to another language In addition to these appointments, specialist advisers will be appointed for the assessment of classified case studies and are not included in the list of appointments. Main Panel B Main Panel B Chair Professor David Price University College London Deputy Chair Professor Dame Muffy Calder* University of Glasgow Members Professor Mike Ashfold University of Bristol Professor John Clarkson University of Cambridge Dr Peter Costigan Independent Professor Paula Eerola University of Helsinki Professor Alison Etheridge University of Oxford Dr Giles Graham Defence Science Technology Laboratory Until Apr 2021 Professor Michael Hinton High Value Manufacturing Catapult Professor Andrew Holmes University of Melbourne Professor Raymond Jeanloz University of California, Berkeley Mr Ben Johnson Graphic Science Ltd Professor Hilary Lappin-Scott Cardiff University Professor John Ludden Heriot-Watt University Professor Miles Padgett University of Glasgow -
Unit 3 :Electronic Spectroscopy Contents
UNIT 3 :ELECTRONIC SPECTROSCOPY CONTENTS • PHOTOELECTRON SPECTROSCOPY-INTRODUCTION • PRINCIPLE • INSTRUMENTATION INTRODUCTION • Photoelectron spectroscopy (PES) is the energy measurements of photoelectrons emitted from solids, gases, or liquids by the photoelectric effect. • Depending on the source of ionization energy, PES can be divided accordingly into Ultraviolet Photoelectron Spectroscopy (UPS) and X- ray Photoelectron Spectroscopy The photoelectric effect is a phenomenon in which electrons are ejected from the surface of a metal when light is incident on it. These ejected electrons are called photoelectrons. It is important to note that the emission of photoelectrons and the kinetic energy of the ejected photoelectrons is dependent on the frequency of the light that is incident on the metal’s surface. The process through which photoelectrons are ejected from the surface of the metal due to the action of light is commonly referred to as photoemission. Explaining the Photoelectric Effect: The Concept of Photons The photoelectric effect cannot be explained by considering light as a wave. However, this phenomenon can be explained by the particle nature of light, in which light can be visualized as a stream of particles of electromagnetic energy. These ‘particles’ of light are called photons. The energy held by a photon is related to the frequency of the light via Planck’s equation: E = h휈 = hc/λ Where, •E denotes the energy of the photon •h is Planck’s constant •휈 denotes the frequency of the light •c is the speed of light (in a vacuum) •λ is the wavelength of the light Threshold Energy for the Photoelectric Effect For the photoelectric effect to occur, the photons that are incident on the surface of the metal must carry sufficient energy to overcome the attractive forces that bind the electrons to the nuclei of the metals. -
The Science Case for 4GLS
University of Huddersfield Repository Allan, R.J. et al. The Science Case for 4GLS Original Citation Allan, R.J. et al. (2001) The Science Case for 4GLS. Research Report. Daresbury Laboratory. This version is available at http://eprints.hud.ac.uk/id/eprint/20020/ The University Repository is a digital collection of the research output of the University, available on Open Access. Copyright and Moral Rights for the items on this site are retained by the individual author and/or other copyright owners. Users may access full items free of charge; copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for personal research or study, educational or not-for-profit purposes without prior permission or charge, provided: • The authors, title and full bibliographic details is credited in any copy; • A hyperlink and/or URL is included for the original metadata page; and • The content is not changed in any way. For more information, including our policy and submission procedure, please contact the Repository Team at: [email protected]. http://eprints.hud.ac.uk/ The Science Case 4GLS International Advisory Committee Prof Dr Gerd Materlik CEO DIAMOND UK (formerly DESY, Germany) Prof Gennady Kulipanov Deputy Director, Budker Institute of Nuclear Physics, Russia Prof Ilan Ben Zvi NSLS, Brookhaven National Laboratory Dr Paul Dumas LURE, France Dr George Neil Deputy FEL Manager, Jefferson Laboratory Prof Ingolf Lindau MAXLAB,University of Lund, Sweden Dr Richard Walker Sincrotrone -
Newsletter Summer / Autumn 2011
Darren graham Congratulations to Dr Darren Graham who was nics?’ recently awarded the very prestigious EPSRC Career Acceleration Fellowship, which he will hold in the Darren will be col- PSI for the next five years. laborating with Nigel Scrutton and Steve The fellowship entitled, ‘Terahertz electron para- Rigby (MIB), David magnetic resonance: a window on biological exploi- Collison and Eric tation of quantum mechanics’, will focus on con- McInnes (EPSRC EPR structing a novel electron paramagnetic resonance facility), Hiroyuki (EPR) spectrometer operating in the terahertz spec- Nojiri (Tohoku Uni- tral range. By utilising the sub-picoseconds capabili- versity), as well as ties of ultrafast laser spectroscopy, this new instru- instrument manufac- ment will enable Darren to address a fundamental turers, Spectra- question in enzyme catalysis, ‘Have biological cata- Physics Lasers and lysts (enzymes) evolved to exploit quantum mecha- Bruker. Dr Darren Graham Newsletter sUMMER / autumn 2011 This newsletter consists of a combination of articles, highlighting both recent grant successes and those of a personal nature. Items for future newsletters and/or the PSI website should be sent to [email protected]. CONTROLLED SYNTHESIS OF TUNED BANDGAP NANODIMENSIONAL ALLOYS Research by members of the PSI aimed at optimizing composition. An important task was to prove that the light-harvesting properties of chalcogenide quan- the particles have a uniform composition. This was tum dots has been published in Journal of the American achieved using energy-filtered transmission electron Chemical Society, widely regarded as the most prestig- microscopy in the Manchester Materials Science ious journal in Chemistry. Centre and by PSI members using X-ray photoelec- tron spectroscopy at the SuperESCA beamline at the The work by Prof Paul O’Brien, Dr Mohammad ELETTRA synchrotron in Trieste. -
Main Panel E
Panel E Main Panel E Chair Professor Dame Julia Higgins Imperial College London Members Professor Robert Birgeneau University of California, Berkeley, USA Professor Sir John Pendry Imperial College London Professor Manfred Reetz Max-Planck-Institute für Züchtungforschung, Germany Professor Jeremy Sanders University of Cambridge Professor Steve Sparks University of Bristol Professor Carl Wunsch Massachusetts Institute of Technology, USA Observers Dr Helen Butler Natural Environment Research Council Dr Elizabeth Fellman Natural Environment Research Council Dr Jason Green Engineering and Physical Sciences Research Council Secretariat Miss Morag Hunter University of Newcastle upon Tyne Ms Lisa Brooks University of Central Lancashire 26 RAE 03/2007 Panel E Sub-panel 17 – Earth Systems and Environmental Sciences Chair Professor Steve Sparks University of Bristol Members Professor Peter Burkill Sir Alister Hardy Foundation for Ocean Science Professor Dianne Edwards Cardiff University Professor C Mary Fowler Royal Holloway, University of London Professor Alexander Halliday University of Oxford Professor Roy Harrison University of Birmingham Professor Timothy Jickells University of East Anglia Professor Georgina Mace Imperial College London Mr Andrew MacKenzie Rio Tinto plc Professor Nick McCave University of Cambridge Professor G David Price University College London Professor James Prosser University of Aberdeen Professor Ernest Rutter University of Manchester Professor Keith Shine University of Reading Professor John Simpson Bangor University -
Introduction to X-Ray Photoelectron Spectroscopy
Introduction to x-ray photoelectron spectroscopy Cite as: J. Vac. Sci. Technol. A 38, 063204 (2020); https://doi.org/10.1116/6.0000412 Submitted: 22 June 2020 . Accepted: 31 August 2020 . Published Online: 24 September 2020 Fred A. Stevie, and Carrie L. Donley COLLECTIONS Paper published as part of the special topic on Special Topic Collection: Reproducibility Challenges and Solutions ARTICLES YOU MAY BE INTERESTED IN Assessment of the frequency and nature of erroneous x-ray photoelectron spectroscopy analyses in the scientific literature Journal of Vacuum Science & Technology A 38, 061204 (2020); https:// doi.org/10.1116/6.0000685 XPS guide: Charge neutralization and binding energy referencing for insulating samples Journal of Vacuum Science & Technology A 38, 031204 (2020); https:// doi.org/10.1116/6.0000057 Procedure which allows the performance and calibration of an XPS instrument to be checked rapidly and frequently Journal of Vacuum Science & Technology A 38, 043206 (2020); https:// doi.org/10.1116/6.0000224 J. Vac. Sci. Technol. A 38, 063204 (2020); https://doi.org/10.1116/6.0000412 38, 063204 © 2020 Author(s). ARTICLE avs.scitation.org/journal/jva Introduction to x-ray photoelectron spectroscopy Cite as: J. Vac. Sci. Technol. A 38, 063204 (2020); doi: 10.1116/6.0000412 Submitted: 22 June 2020 · Accepted: 31 August 2020 · View Online Export Citation CrossMark Published Online: 24 September 2020 Fred A. Stevie1,a) and Carrie L. Donley2,b) AFFILIATIONS 1Analytical Instrumentation Facility, North Carolina State University, Raleigh, North Carolina 27695 2Chapel Hill Analytical and Nanofabrication Laboratory, University of North Carolina, Chapel Hill, North Carolina 27599 Note: This paper is part of the Special Topic Collection on Reproducibility Challenges and Solutions. -
Thesis Submitted in Fulfilment of Requirement for the Degree of Dphil in Materials at the University of Oxford
The Surface Chemistry and Interface Engineering of Lead Sulphide Colloidal Quantum Dots for Photovoltaic Applications Neo Chi Jin, Darren Mansfield College A thesis submitted in fulfilment of requirement for the degree of DPhil in Materials at the University of Oxford Abstract This thesis examines the effect of lead sulphide (PbS) CQDs’ surface chemistry and interfaces to their photovoltaic performance. Using PbS CQDs as the starting material, cation-exchange was utilised to form PbS/CdS core/shell CQDs, which were thoroughly characterised and the improved surface passivation was shown by increased photoluminescence yield and lifetime. The core/shell CQDs were incorporated into a ZnO/CQD heterojunction solar cell device and showed a substantial improvement of the mean open-circuit voltage (Voc), from 0.4 V to 0.6 V, over PbS reference devices. By optimising shell thickness and surface ligands, core/shell CQD devices with average device efficiency of 5.6 % were fabricated as compared to 3.0 % for unshelled PbS devices. The lower defect density due to better passivation confers lower carrier density in core/shell CQD film. To take advantage of low defect concentration and to aid charge extraction, a 3 dimensional quantum funnel concept was sought of by blending two populations of PbS/CdS CQDs of different sizes. By incorporating a blend component within a heterojunction device, even when the device thickness is beyond what is optimal for the depletion width and the diffusion length of the system, high Voc is still maintained. In a separate study, a p-i-n device strategy was examined, and with this approach, a maximum device efficiency of 6.4 % was achieved. -
Electron Spectroscopy of Rutile-Type Metal Oxides Sigrun Eriksen B.Sc
1 Electron Spectroscopy of Rutile-type Metal Oxides r Sigrun Eriksen B.Sc. A.R.C.S. A thesis submitted for the degree of Doctor of Philosophy of the University of London and for the Diploma of Membership of Imperial College. Department of Chemistry Imperial College London SW7 2AZ August 1987 2 Abstract This thesis presents a study of defective and defect-free rutile TiO (110) surfaces, using ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS) and high resolution electron energy loss spectroscopy (HREELS). The use of argon ion and electron bombardment for creation of surface defects is investigated. An oxygen -20 -2 desorption cross section of 1.5 x 10 cm is found for electron irradiation, and a desorption mechanism suggested. An electronic excitation due to the oxygen vacancies is identified; this modifies the effective surface dielectric constant. The oscillator strength for this excitation is found to be 0.1, indicating an allowed transition. The adsorption of water on the TiO2(110) surface is also studied. From HREELS and He(II) UPS, it is found that water will not adsorb on a defect-free TiO^MIO) surface at 300K, but will adsorb on a surface in which oxygen vacancy defects have been created. It is shown that this adsorption involves dissociation of the water molecule, leaving 0-H species bonded to the surface. Finally, the effects of oxygen vacancies on the rutile SnO^MIO) surface are investigated. It is confirmed that argon ion bombardment gives rise to selective oxygen loss, and the Sn species on the 2 + 4 + resulting defective surface are Sn and Sn ; total oxygen loss is never greater than 502. -
Synthesis of the Digital Lives Research Project
DIGITAL >>LIVES An Initial Synthesis i Research Conference 2009 DIGITAL LIVES Personal Digital Archives for the 21st Century >> An Initial Synthesis by Jeremy Leighton John with Ian Rowlands Peter Williams Katrina Dean THIS IS VERSION 0.2 WELCOMING SUGGESTIONS & FEEDBACK AN ACCOUNT OF THE DIGITAL LIVES RESEARCH PROJECT 2009 A research project funded by the Arts and Humanities Research Council Grant BLRC 8669 (Research Grants: Speculative) A Digital Lives Research Paper ii A synthesis of the Digital Lives research project, led by the British Library, in partnership with University College London and the University of Bristol, and funded by the Arts and Humanities Research Council http://www.bl.uk/digital-lives/index.html The synthesis considers the curation of personal digital archives across the whole archival lifecycle Beta Version 0.2, 03 March 2010 Possible citation style: John, J. L.; I. Rowlands; P. Williams; and K. Dean (2010) Digital Lives. Personal digital archives for the 21st century >> an initial synthesis, Digital Lives Research Paper, 03 March 2010, Beta Version 0.2 All hyperlinks will be checked in subsequent versions THE PAPER PRESENTS OUTPUT OF THE DIGITAL LIVES RESEARCH PROJECT: THE OPINIONS AND INTERPRETATIONS EXPRESSED DO NOT NECESSARILY REFLECT THE POLICY OF THE BRITISH LIBRARY iii BETA VERSION: 0.2 03 March 2010 A Note on the Beta Version In the spirit of the times we are making the Initial Synthesis available first as a Beta Version. Readers are invited to send their thoughts and suggestions to the email address: [email protected] We may not be able to reply to all email messages: for one thing we do not know how many there will be, but we shall read all of them. -
X-Ray Photoelectron Spectroscopy
XX--rayray PhotoelectronPhotoelectron SpectroscopySpectroscopy RogerRoger Smart,Smart, StewartStewart McIntyre,McIntyre, MikeMike Bancroft,Bancroft, IgorIgor BelloBello && FriendsFriends DepartmentDepartment ofof PhysicsPhysics andand MaterialsMaterials ScienceScience CityCity UniversityUniversity ofof HongHong KongKong SurfaceSurface ScienceScience Western,Western, UWOUWO Introduction Photoelectric effect Photoelectric effect Einstein, Nobel Prize 1921 Photoemission as an analytical tool Kai Siegbahn, Nobel Prize 1981 XPS, also known as ESCA, is the most widely used surface analysis technique because of its relative simplicity in use and data interpretation. XPS X-ray Photoelectron Spectroscopy ESCA Electron Spectroscopy for Chemical Analysis UPS Ultraviolet Photoelectron Spectroscopy PES Photoemission Spectroscopy AnalyticalAnalytical MethodsMethods --- X-ray Photoelectron Spectroscopy (XPS) Photon ν ϕ hν KE = h - (EB+ ) Kinetic Photoelectron Energy E 0 v XPS spectrum: φ Intensities of photoelectrons 0 Ef versus EB or KE VB Binding — Elemental identification and Energy 3s chemical state of element 2p 2s — Relative composition of the constituents in the surface region 1s — Valence band structure Binding Energy Reference K.E. = hνφ -B.E..F - sample - (φφ- ) K.E. = hνφ -B.E. - spec sample .F sample- = hνφ -B.E. - e .F spec Vacuum level Vacuum level φspec φsample Fermi level Fermi level B.E.F core level B.E..F = hνφ - K.E. - spec Instrumentation • Electron energy analyzer • X-ray source • Ar ion gun • Neutralizer • Vacuum system • Electronic controls • Computer system Ultrahigh vacuum system < 10-9 Torr (< 10-7 Pa) • Detection of electrons • Avoid surface reactions/ contaminations Background: Photoelectrons with energy loss Peak: Photoelectrons without energy loss Relative binding energies and ionization cross-section for U For p, d and f peaks, two peaks are observed.