Despite remarkable advancements in the theory and spectroscopy, and the myriad tools for measuring tunneling currents through molecules, a central problem in the field of Molecular Electronics is the lack of robust, generalizable, scalable methods for leveraging self-assembly to construct devices. In this talk I will discuss two methods for using self-assembled monolayers (SAMs) to define the smallest dimension of tunneling-based devices; eutectic Ga-In (EGaIn) and Nanoskiving. EGaIn is a non-Newtonian liquid alloy with the remarkable ability to retain tapered structures simply by stretching it between to surfaces. These tapered structures can then be used to form reversible, non-damaging micron-sized contacts to SAMs of a variety of different types of molecules. Such a tip is pictured in the top figure, along with a cartoon of a tunneling junction and the J/V curves of three SAMs for which the conjugation pattern is shown to affect the tunneling probability via quantum interference. Pictured below are three different nano-gap electrodes fabricated by Nanoskiving, an emerging nanofabrication technique based on edge lithography. These electrodes are formed by separating two thin films of gold by a SAM and then slicing them using a diamond knife (Nanoskiving) to produce addressable structures that are millimeters long and separated by ~2 nm. They are electrically continuous and the separation of the electrodes can be controlled with sub-nanometer resolution without a clean room or any photo or e-beam lithography.
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