hide
Free keywords:
-
Abstract:
H60O6, HBT) deposited on a (111)-oriented Au single crystal and a polycrystalline indium tin oxide (ITO) substrate has been carried out using X-ray absorption spectroscopy. Films of thicknesses between 2 nm and 15 nm were prepared in UHV by evaporation of HBT [which exhibits a discotic liquid crystalline (LC) bulk phase] from a Knudsen cell. Thickness and composition of the HBT films were determined using X-ray photoelectron spectroscopy (XPS). For the thinnest films with thicknesses in the monolayer regime, the orientational analysis reveals a pronounced orientation of the disc-shaped HBT molecules parallel to the Au surface. For thicker films, a significantly reduced anisotropy is observed with the molecular plane oriented more normal to the Au surface. In the case of the ITO-substrates, no significant differences were observed between different thickn esses and the average orientation of the molecular planes was predominantly normal to the surfaces, as for the thicker films on the Au substrate.
