Pressure-Induced Restructuring of a Monolayer Film Nanojunction Produces Threshold and Power Law Conduction

The electrical conduction of metal−molecule−metal junctions formed between Au-supported self-assembled monolayers of structurally different 1-hexanethiol, 1-decanethiol, and ferrocenyl-1-undecanethiol and a Pt-coated atomic force microscope (AFM) tip has been measured under different compression forces using conducting-probe AFM. The observed junction resistance had two distinct power law scaling changes with the compression force. Different scaling regions were assigned to the change in the contact area, tunneling distance, number of conduction pathways, and structure of the film under compression.