Orientation of Adsorbed C₆₀ Molecules Determined via X-Ray Photoelectron Diffraction

Although significant insight into fullerene-substrate interactions has come from recent surface science studies, to date there has been no unambiguous way to determine the molecular orientation of adsorbed C₆₀ molecules. We show that photoelectron diffraction patterns from monolayer C₆₀ films are directly related to the intramolecular structure of C₆₀. This allows for the first time a direct and unambiguous identification of the molecular orientation of the adsorbed fullerenes with respect to the substrate. A variety of molecular orientations is observed on different substrates.