UV photoemission study on fullerene molecules deposited on defect-rich carbon surfaces

Submonolayers of C₆₀ molecules have been deposited on different carbon substrates (pristine HOPG, argon-ion irradiated HOPG and amorphous carbon) and investigated by means of Ultraviolet Photoelectron Spectroscopy. The desorption behavior and spectral changes in the valence band were examined as a function of the sample temperature. Strong fullerene-substrate interaction (chemisorption) was observed on defect-rich surfaces (irradiated HOPG, a-C), indicated by binding energy shifts and broadening of C₆₀ VB features. These chemisorbed species proved to be more resistant against temperature-induced desorption than usually observed for physisorbed molecules on pristine HOPG. The results presented here suggest that deposition of fullerenes on heated substrates might be a feasible method of surface nanostructuring by preferential chemisorption on defects.