title: Charge transport in a zinc-porphyrin single-molecule junction.
abstract: We have investigated charge transport in ZnTPPdT-Pyr (TPPdT: 5,15-di(p-thiolphenyl)-10,20-di(p-tolyl)porphyrin) molecular junctions using the lithographic mechanically controllable break-junction (MCBJ) technique at room temperature and cryogenic temperature (6 K). We combined low-bias statistical measurements with spectroscopy of the molecular levels in the form of I(V) characteristics. This combination allows us to characterize the transport in a molecular junction in detail. This complex molecule can form different junction configurations, having an observable effect on the trace histograms and the current-voltage (I(V)) measurements. Both methods show that multiple, stable single-molecule junction configurations can be obtained by modulating the interelectrode distance. In addition we demonstrate that different ZnTPPdT-Pyr junction configurations can lead to completely different spectroscopic features with the same conductance values. We show that statistical low-bias conductance measurements should be interpreted with care, and that the combination with I(V) spectroscopy represents an essential tool for a more detailed characterization of the charge transport in a single molecule.
authors: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft, The Netherlands.
authors: Mickael L
authors: ML
authors: Perrin
authors: Christian A
authors: CA
authors: Martin
authors: Ferry
authors: F
authors: Prins
authors: Ahson J
authors: AJ
authors: Shaikh
authors: Rienk
authors: R
authors: Eelkema
authors: Jan H
authors: JH
authors: van Esch
authors: Jan M
authors: JM
authors: van Ruitenbeek
authors: Herre S J
authors: HS
authors: van der Zant
authors: Diana
authors: D
authors: Dulić