报告人:Frank Schreiber教授(Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany)
报告题目:X-ray standing waves for structurally resolved spectroscopy
报告时间:10:00 AM, Sep. 28th (Thursday)
报告地点:909-B
Abstract
In this lecture, we outline the opportunities provided by a technique called X-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 transitions in a crystal or on the surface of a crystal. The intensity of these transitions can then be very finely modulated by tuning the incoming beam through the Bragg condition. It turns out that these can be used to determine the structure of adsorbates or thin films with a precision better than 0.01 nanometers. We will discuss examples of organic semiconductors on metal contacts in which the exact geometric structure including the distortion of the molecules is a key to the understanding of interface dipoles and associated workfunction changes as well as electron injection efficiencies in devices.

Biography
- 1987 � 1992 undergraduate studies in physics at Bochum University
- 1992 Diploma (with distinction)
- 1995 Dr. rer. nat. (with distinction) at Bochum University
- 1995/1996 Research 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
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