Scanning Tunneling Microscopy Investigations on Heteroepitaxially Grown Overlayers of Cu-Phthalocyanine on Au(111) Surfaces
With its ultrahigh resolution, the STM provides an outstanding capability for the structural analysis of the molecular orderings occurring on single crystalline substrates.
We used the STM to image all steps of the multiple heteroepitaxial process, which leads to highly ordered and ultrathin layers of the Cu-phthalocyanine molecules on single crystalline gold films, previously grown on freshly cleaved mica sheets.
The structure of the organic overlayer is commensurable with the Au(111) surface as deduced from both reflection high-energy electron diffraction (RHEED) and STM data. The film shows a novel, nearly quadratic structure which is strongly influenced by the interaction with the Au substrate and different from that in bulky material of Cu-phthalocyanine. For the determination of the structure of organic layers the combination of in situ RHEED and STM is very useful and allows to overcome the limitations of both surface analysis techniques.
KeywordsScanning Tunneling Microscopy Scanning Tunneling Microscopy Image Reflection High Energy Electron Diffraction Organic Thin Film RHEED Pattern
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