Resonant heating and substrate-mediated cooling of a single C60 molecule in a tunnel junction

We study the influence of different metallic substrates on the electron induced heating and heat dissipation of single C60 molecules in the junction of a low temperature scanning tunneling microscope. The electron current passing through the molecule produces a large amount of heat due to electron-phonon coupling, eventually leading to thermal decomposition of the fullerene cage. The power for decomposition varies with electron energy and reflects the resonance structure participating in the transport. The average value for thermal decomposition of C60 on Cu(110) amounts to 21 μW, while it is much lower on Pb(111) (2.9 μW) and on Au(111) (1.0 μW). We ascribe this difference to the amount of charge transfer into C60 upon adsorption on the different surfaces, which facilitates molecular vibron quenching by electron-hole pair creation.