Geometric and electronic structure of a C60 monolayer on Ag(100)

Using scanning tunneling microscopy and spectroscopy and first principles calculations, we have systematically studied the morphological and electronic structures of a C-60 monolayer on Ag(100). Our results reveal that the bright-dim contrast has a definite geometric origin and there are two types of dim C-60 molecules, one a monomer and the other a dimer. With distinctive electronic properties and distinctive charge transfers in the differently adsorbed C-60 molecules, this C-60 monolayer is highly inhomogeneous and aperiodic.