Nanosphere Templates for Molecule Adsorption

Organic semiconductor molecules are of interest for numerous applications including the use of planar aromatic hydrocarbons as a model system for graphene. A fundamental understanding of how surface corrugation affects molecular adsorption and positioning can affect the way that the layers are formed, and consequently determine the properties they display. This work is an investigation into the interaction of Coronene (Cor) and Pentacene (Pn) molecules with highly corrugated nanosphere templated surfaces using Scanning Tunneling Microscopy/Spectroscopy (STM/STS). Temperature variations in Coronene adlayer structure on Au(111) are discussed as a reference for adsorption on a planar, metallic surface and statistical image analysis is implemented as a method of STM data extraction. Using fullerene molecules with W and Mo thin film substrates, we synthesize nanospheres which vary in their electronic structure while mostly retaining the initial spherical shape. This provides a corrugated template which can be used for molecular adsorption. The molecule positioning and electronic structure of Coronene and Pentacene are detailed on nanosphere templates. For both of these molecular structures, the underlying nanosphere corrugation significantly affects the positioning of the molecules compared to weakly interacting surfaces. Additionally, Pn molecules have several co-existing adsorption structures due to the small size of the molecule compared to the nanosphere corrugation.