CURRENT-VOLTAGE CHARACTERISTICS OF SELF-ASSEMBLED MONOLAYERS BY SCANNING-TUNNELING-MICROSCOPY

This paper presents a comparison of the theoretical and experimental c urrent-voltage (I-V) characteristics of a self-assembled monolayer of alpha,alpha'-xylyl dithiol molecules on a gold substrate measured with a scanning tunneling microscope probe. Good quantitative agreement is obtained with the tip-molecule distance as the only ''fitting paramet er. Several other thiol-coupled molecules that we have studied also sh ow similar agreement. The conceptual picture presented in this paper c ould be useful for the interpretation of I-V measurements on molecular monolayers in general.