Dresden 2003 – wissenschaftliches Programm
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O: Oberflächenphysik
O 24: Postersitzung (Epitaxie und Wachstum, Oxide und Isolatoren, Elektronische Struktur, Oberfl
ächenreaktionen, Adsorption an Oberfl
ächen, Organische Dünnschichten)
O 24.54: Poster
Mittwoch, 26. März 2003, 14:30–17:30, P1
Photodesorption of small molecules adsorbed on ultrathin Ag-films — •Olaf Weiße, Claudia Wesenberg, and Eckart Hasselbrink — Inst. für Phys. Chemie, FB Chemie, Universität Essen, Universitätsstr. 5, D-45117 Essen, Deutschland
Since the early 1990, Ag is known to grow on the Si(100) surface in the layer-by-layer mode.The resulting surface form an epitaxial Ag(111) layer. These ultrathin Ag-films (5-100 ML) are optimal to study the electron dynamics in such films and the influence of the film thickness on charge transferto the adsorbate and subsequent photodesorption. The growth mode and the surface structure is monitored by using LEED and AES techniques. In our experiments, N2O is chosen as the probe molecule. Its adsorption is performed 90 K on the Ag covered Si(100) surface. Photodesorption is induced using a Nd-YAG laser (266 nm) and the desorbed molecules are detected by QMS. The film thickness is varied expecting to obtain information about the charge transfer dynamics between the ultrathin Ag-film and the N2O adsorbate.