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Germanium was deposited onto highly oriented pyrolytic graphite (HOPG) with and without antimony in ultra-high vacuum. The surface morphology was analyzed using in situ scanning tunneling microscopy (STM) at room temperature (RT). The film grows exclusively in 3D island mode and was affected significantly by substrate defects. At initial stage, nucleation of cluster occurred at step edges and defect sites. Later, we found various types of Ge nanostructures on HOPG in different deposition conditions and stages, including cluster chains, cluster islands, nanowires, and double layer ramified islands at RT. Compact Ge islands were observed when depositing at a substrate temperature of 450 K or after an annealing at 600 K following RT deposition. In addition, the pre-deposited Sb on graphite enhances the sticking probability and suppresses the surface diffusion of Ge atoms, resulting in a significant increase in Ge cluster island density on HOPG terraces. [ABSTRACT FROM AUTHOR]

We present a low-temperature scanning tunneling microscopy investigation revealing the formation of a long range ordered α-sexithiophene (6T) monolayer nanostripe array on highly ordered pyrolytic graphite, with thiophene ring units oriented parallel to the surface. The 6T monolayer nanostripe is an effective molecular nanotemplate for the assembly of an ordered “zigzag” C60 chain array, accompanied by a slight structural modification of the underlying 6T nanostripes due to donor-acceptor intermolecular interactions between 6T and C60 molecules. [ABSTRACT FROM AUTHOR]