Ultra-fast charge transfer between fullerenes and a gold surface, as prepared by electrospray deposition

Monolayers of C60 and the functionalised fullerene phenyl-C61-butyric acid methyl ester (PCBM) have been prepared on Au(1 1 1) by in situ electrospray deposition. The observation of super-spectator/super-Auger decay in resonant photoemission spectroscopy (RPES) of C60 confirms monolayers prepared using electrospray undergo ultra-fast charge transfer as per previous studies of C60 monolayers on Au(1 1 1) prepared by sublimation. For PCBM, X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) show the lowest unoccupied molecular orbital (LUMO) of the molecule overlaps the Fermi-level of the metal surface. Despite this, no evidence of ultra-fast charge transfer is observed in the RPES of PCBM.