Survey of structural and electronic properties of C60 on close-packed metal surfaces

摘要

The adsorption of buckminsterfullerene (C60) on metal surfaces has been investigated extensively for its unique geometric and electronic properties. The two-dimensional systems formed on surfaces allow studying in detail the interplay between bonding and electronic structures. Recent studies reveal that C60 adsorption induces reconstruction of even the less-reactive close-packed metal surfaces. First-principles computations enable access to this important issue by providing not only detailed atomic structure but also electronic properties of the substrate–adsorbate interaction, which can be compared with various experimental techniques to determine and understand the interface structures. This review discusses in detail the ordered phases of C60 monolayers on metal surfaces and the surface reconstruction induced by C60 adsorption, with an emphasis on the different types of reconstruction resulting on close-packed metal surfaces. We show that the symmetry matching between C60 molecules and metal surfaces determines the local adsorption configurations, while the size matching between C60 molecules and the metal surface lattice determines the supercell sizes and shapes; importantly and uniquely for C60, the number of surface metal atoms within one supercell determines the different types of reconstruction that can occur. The atomic structure at the molecule–metal interface is of crucial importance for the monolayer’s electronic and transport properties: these will also be discussed for the well-defined adsorption structures, especially from the perspective of tuning the electronic structure via C60–metal interface reconstruction and via relative inter-C60 orientations.