Adsorption of Fluorinated Fullerene Molecules on Metallic and Semiconducting Surfaces

Scanning tunneling microscopy, scanning tunneling spectroscopy (STM/STS), and X-ray photoelectron spectroscopy (XPS) were used in this study. The electronic density of states for fluorofullerene molecules on the surface of semiconductors and metals has been calculated ab initio. The behavior of fluorofullerene molecules with different stoichiometric compositions is considered. It has been found that a dipole molecule C60F18 prefers to be oriented by fluorine atoms towards the semiconductor surface. For a metallic surface, the dipole moment can deviate from the direction of the normal to the surface, which is caused by the balance between the intermolecular interaction and the interaction between the molecule and the surface. Fluorofullerene molecules tend to lose fluorine atoms over time, which allows them to be used as a source of fluorine in the processes of fluorination of metallic surfaces and a local chemical reaction on the semiconducting surface.