Dresden 2017 – wissenschaftliches Programm
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MI: Fachverband Mikrosonden
MI 9: Progress of Instrumentation and Methods for the Surface Analysis (PEEM, LEED)
MI 9.1: Vortrag
Donnerstag, 23. März 2017, 11:15–11:30, MER 02
In-situ electrochemistry in photoemission microscopy — •Slavomir Nemsak1, Claus M. Schneider1, and Andrei Kolmakov2 — 1PGI-6, Forschungszentrum Juelich, 52425 Juelich, Germany — 2Center for Nanoscale Science and Technology, NIST, Gaithersburg, MD, USA
Until recently, photoemission electron microscopy (PEEM) could not be used in studies of solid/liquid interfaces due to major instrumental and experimental difficulties. The usual technique of differential pumping, which allows photoelectrons to reach the detection in ambient pressure photoemission spectroscopy, cannot be simply realized in PEEM, mostly due to the presence of high potential difference between a specimen and extractor lens. One of the ways to overcome this problem is to use a sample capped with electron transparent molecularly impermeable membrane, which would leave the vacuum conditions between the lens and the sample unaffected [Kolmakov, A et al., Nature Nanotechnol. 6, 651 (2011)]. Application of different potentials at various points on the sample is another ingredient, which would enable doing spectromicroscopy with electrochemistry.
We present a working concept of electrochemical cell inside a photoemission microscope. Our demonstration uses a capping membrane made of a few-layer graphene. In this configuration, the graphene membrane acts also as a top electrode Kolmakov, A et al., Topics in Catalysis 59, 448 (2016)]. A liquid contained in the cell is then imaged primarily with secondary or Auger photoelectrons under operating conditions.