Charge State Control of Molecules Reveals Modification of the Tunneling Barrier with Intramolecular Contrast

Zusammenfassung

From scanning tunneling microscopy and spectroscopy experiments it is shown that control over the charge-state of individual molecules adsorbed on surfaces can be obtained by choosing a substrate system with an appropriate workfunction. The distribution of the additional charge is studied using difference images. These images show marked intramolecular contrast.