Presenter: Prof. Frank Schreiber (Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany)
Topic: X-ray standing waves for structurally resolved spectroscopy
Time: 10:00 AM, Sep. 28th (Thursday)
Location: 909-B
Abstract
In this lecture, we outline the opportunities provided by a technique calledX-ray standing waves (XSW).If an incoming X-ray wave and a reflected X-ray wave,e.g. caused by Bragg diffraction from the lattice planes of a crystal,overlap, they can form a standing wave pattern.This gives rise to an X-ray intensity pattern,which is modulated in space on the length scale of the lattice planes,i.e. sub-nanometers.Importantly, it can be employed to excite characteristic transitionsin a crystal or on the surface of a crystal.The intensity of these transitions can then be very finely modulatedby tuning the incoming beam through the Bragg condition.It turns out that these can be used to determine the structure of adsorbatesor thin films with a precision better than 0.01 nanometers.We will discuss examples of organic semiconductorson metal contacts in which the exact geometric structure including the distortionof the molecules is a key to the understanding of interface dipoles andassociated workfunction changes as well as electron injection efficienciesin devices.
Biography
1987-1992undergraduate studies in physics at Bochum University
1992 Diploma (with distinction)
1995 Dr. rer. nat. (with distinction) at Bochum University
1995/1996Research in Paris and Prague
1996-1997 Post-Doctoral Fellow at Princeton University
1998-2002 Research Assistant in Stuttgart (University and MPI-MF)
2002 Habilitation in Stuttgart
2002-2004 University Lecturer at the University of Oxford and Fellow of Wadham College
since December 2004 Professor (Chair) at Tübingen University
Contact: Steffen Duhm
Editor: Juan Yang