Resonances in low-energy electron transmission through organized organic films: Evidence for molecular quantum wells

Energy-resolved transmission spectroscopy of low-energy photoelectrons thro ugh self-assembled monolayer films on a gold cathode are used to identify e lectron resonances in the film. For films composed of benzene, naphthalene, and anthracene aromatic moieties, the transmission spectra reveal well-def ined vibronic structure, which is quite similar to that found for the corre sponding aromatic molecules in the gas phase. In contrast, the electronic s tate positions are not molecular and indicate a "quantum-well" structure fo rmed by the monolayer film. [S0163-1829(99)01044-9].