C-60 EXCITON QUENCHING NEAR METAL-SURFACES

Employing metal-alkanethiol-C-60 sandwich structures we studied the C- 60 exciton lifetime as a function of distance (1-3 nm) to a metal. Bas ed on the order and compactness of the self-assembling thiol layer a u niform separation of C-60 and metal is achieved. The C-60 exciton life time is measured by pump and second harmonic probe spectroscopy. Even at distances as small as 1 nm classic damping mechanisms prevail, and no evidence for additional decay channels is obtained. For Au and Ag s ubstrates we find a predominance of energy transfer to bulk and to sur face, respectively.