Adsorption and decomposition of C60 molecules on Si(111) surfaces

Abstract

Adsorption of C60 molecules on Si(111)-(7×7) has been studied using scanning tunneling microscopy under ultrahigh vacuum conditions at a variety of temperatures and coverages. At submonolayer coverages, isolated C60 molecules were found to adsorb preferentially in the areas near the three midadatoms within a half unit cell of (7×7) symmetry. At monolayer coverage, the adsorbate–adsorbate interaction changes the molecular bonding sites and causes the local ordering of the C60 adlayer. Thermal annealing to temperatures above 800 °C causes the decomposition of C60 molecules on the Si surface and the formation of SiC clusters.