American Chemical Society
nl8b00304_si_001.pdf (1.13 MB)

Fano Description of Single-Hydrocarbon Fluorescence Excited by a Scanning Tunneling Microscope

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journal contribution
posted on 2018-05-02, 00:00 authored by Jörg Kröger, Benjamin Doppagne, Fabrice Scheurer, Guillaume Schull
The detection of fluorescence with submolecular resolution enables the exploration of spatially varying photon yields and vibronic properties at the single-molecule level. By placing individual polycyclic aromatic hydrocarbon molecules into the plasmon cavity formed by the tip of a scanning tunneling microscope and a NaCl-covered Ag(111) surface, molecular light emission spectra are obtained that unravel vibrational progression. In addition, light spectra unveil a signature of the molecule even when the tunneling current is injected well separated from the molecular emitter. This signature exhibits a distance-dependent Fano profile that reflects the subtle interplay between inelastic tunneling electrons, the molecular exciton and localized plasmons in at-distance as well as on-molecule fluorescence. The presented findings open the path to luminescence of a different class of molecules than investigated before and contribute to the understanding of single-molecule luminescence at surfaces in a unified picture.