Probing Molecular Excited States by Atomic Force Microscopy

Shadi Fatayer, Florian Albrecht, Ivano Tavernelli, Mats Persson, Nikolaj Moll, Leo Gross

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


By employing single charge injections with an atomic force microscope, we investigated redox reactions of a molecule on a multilayer insulating film. First, we charged the molecule positively by attaching a single hole. Then we neutralized it by attaching an electron and observed three channels for the neutralization. We rationalize that the three channels correspond to transitions to the neutral ground state, to the lowest energy triplet excited states and to the lowest energy singlet excited states. By single-electron tunneling spectroscopy we measured the energy differences between the transitions obtaining triplet and singlet excited state energies. The experimental values are compared with density functional theory calculations of the excited state energies. Our results show that molecules in excited states can be prepared and that energies of optical gaps can be quantified by controlled single-charge injections. Our work demonstrates the access to, and provides insight into, ubiquitous electron-attachment processes related to excited-state transitions important in electron transfer and molecular optoelectronics phenomena on surfaces.
Original languageEnglish (US)
JournalPhysical Review Letters
Issue number17
StatePublished - Apr 30 2021
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy


Dive into the research topics of 'Probing Molecular Excited States by Atomic Force Microscopy'. Together they form a unique fingerprint.

Cite this