Thermal-dependent electronic structure at the interface of C-60-adsorbed Si(111)-(7 x 7) surface

We report here the temperature-dependent measurements of the valence spectr a, and the C 1s and the Si 2p core-level spectra of the C-60 adsorbed Si(11 1)-(7 x 7) surface, using photoelectron spectroscopy. At 300 K the valence spectra show the physisorption of most C-60 molecules for a one monolayer C -60 film. After annealing the sample at 1120 K the molecular orbitals disap pear due to the breakdown of the C-60 cage. The C 1s and Si 2p core-level s pectra obtained at the same temperature indicate the progress of SIC format ion at the interface between C60 and the Si(111) surface. After annealing a t 1170 K, the formation of SiC islands is confirmed by the binding energies of the peaks observed in the valence and C 1s core-level spectra. (C) 1999 Elsevier Science B.V. All rights reserved.