Abstract
Energy-resolved transmission spectroscopy of low-energy photoelectrons through self-assembled monolayer films on a gold cathode are used to identify electron resonances in the film. For films composed of benzene, naphthalene, and anthracene aromatic moieties, the transmission spectra reveal well-defined vibronic structure, which is quite similar to that found for the corresponding aromatic molecules in the gas phase. In contrast, the electronic state positions are not molecular and indicate a "quantum-well" structure formed by the monolayer film. [S0163-1829(99)01044-9].