Adsorption and electronic structure of single C₆₀F₁₈ molecule on Si(1 1 1)-7 × 7 surface

Spatially resolved images of an individual C₆₀F₁₈ molecule on Si(1 1 1)-7 × 7 surface obtained from STM and ab initio calculations show that the fluorofullerene molecules interact with the Si(1 1 1) surface with F atoms pointing down towards the surface. A large electric dipole moment of the molecule induces strong polarization on the surface but the charge transfer is small. Comparison between the experimental and calculated images indicates that during the time of image collection, some of the F atoms move to the surface due to F binding energy on a Si surface being nearly twice of the mean value on the C₆₀ molecule.