Individual tetraazaperylene molecules at the edges of self-assembled islands grown on Ag(111) can be deliberately switched in their charge state with the electric field from a vibrating scanning-probe tip. The integrated frequency shift yields the tip-sample force that is due to a single additional electron.

This work was carried out in the group of Prof. Silvio Decurtins / Dr. Shi-Xia Liu in collaboration with Prof. Jascha Repp, University of Regensburg..

References:

• N. Kocic, P. Weiderer, S. Keller, S. Decurtins, S.-X. Liu, J. Repp;
  "Periodic Charging of Individual Molecules Coupled to the Motion of an AFM Tip"
  Nano Lett., 15, 4406-4411, (2015); doi:10.1021/acs.nanolett.5b00711.