Flicker Noise as a Probe of Electronic Interaction at Metal–Single Molecule Interfaces
Author(s):
Olgun Adak, Ethan Rosenthal, Jeffery Meisner, Erick F. Andrade, Abhay N. Pasupathy, Colin Nuckolls, Mark S. Hybertsen, Latha Venkataraman
Journal:
Nano Letters
Year:
2015
Volume:
15
Pages
4143–4149
DOI:
10.1021/acs.nanolett.5b01270
Abstract:
Charge transport properties of metal–molecule interfaces depend strongly on the character of molecule–electrode interactions. Although through-bond coupled systems have attracted the most attention, through-space coupling is important in molecular systems when, for example, through-bond coupling is suppressed due to quantum interference effects. To date, a probe that clearly distinguishes these two types of coupling has not yet been demonstrated. Here, we investigate the origin of flicker noise in single molecule junctions and demonstrate how the character of the molecule–electrode coupling influences the flicker noise behavior of single molecule junctions. Importantly, we find that flicker noise shows a power law dependence on conductance in all junctions studied with an exponent that can distinguish through-space and through-bond coupling. Our results provide a new and powerful tool for probing and understanding coupling at the metal-molecule interface.