First-principles study of a single C-60 cluster adsorbed on KBr(100)

Abstract

Atomic and electronic structure of the C-60 monomer adsorbed KBr(100) surface has been studied by using density-functional theory calculations. We found that a single C-60 cluster favors an adsorption configuration where a hexagon ring of C-60 adsorbs atop the surface K atom. The energy gain by adsorption is as small as 0.37 eV, and the resulting structural modifications of the C-60 cluster and the KBr(100) substrate are negligible. Calculated density of states and charge characters indicate that this structure is stabilized by a weak interaction between the p-orbitals of interfacial C and Br atoms. The present calculations are found to be useful in understanding the structural properties of a close-packed C-60 monolayer phase grown on KBr(100) in a recent atomic force microscopy study. (C) 2008 Elsevier B.V. All rights reserved.