Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 4: Organische Dünnschichten I

O 4.2: Vortrag

Montag, 8. März 2004, 11:30–11:45, H43

Molecular orientation in perylene thin films on Al₂O₃/Ni₃Al(111) — •M. B. Casu, A. Schöll, K. R. Bauchspieß, D. Hübner, Th. Schmidt, C. Heske, and E. Umbach — Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg

Organic Field Effect Transistors (OFETs) are a rapidly developing field and many efforts are directed towards their optimisation. We have investigated thin films of perylene, a model candidate as OFET material, grown by organic molecular beam deposition (OMBD) on Al₂0₃/Ni₃Al(111). By means of Near-Edge X-ray Absorption Fine Structure (NEXAFS), we studied the influence of the growth parameters on the molecular orientation and the consequential changes in the electronic fine structure. We find that it is possible to tailor the molecular orientation of perylene by using different sets of growth parameters. Thus, it is possible to grow films in which the chosen molecular orientation is optimal for a charge transport between source and drain. We also investigated their thermal stability and their vacuum stability as a function of time (perylene is characterised by a high vapour pressure). As will be discussed, the overall results are helpful to understand the interactions between the organic molecules and the substrate and to answer the question whether perylene can be used for real OFET devices. (Financed by DFG, SP 1121, Um 618-2)