Current density-voltage characteristics are presented for a molecular structure of the form metal/organic-multilayer/metal for which the rectifierlike forward bias current density dependence is unequivocally associated with zwitterionic molecules. By placing passive organic barriers between the metal layers and the active molecules we prove that Schottky barrier effects are not important. This is the clearest evidence so far for molecularly controlled rectification, the basis for molecular electronics.

• Received 13 August 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.218