Study of molecular junctions with a combined surface-enhanced Raman and mechanically controllable break junction method.

We have developed a combined surface-enhanced Raman spectroscopy (SERS) and break junction method to detect and characterize molecules between two microfabricated electrodes separated with a gap that can be continuously adjusted from a few angstroms to nanometers. It allows us to obtain a vibrational fingerprint of the adjustable molecular junction while performing electron transport measurements on the molecule simultaneously. This new approach will provide not only new insights into electron transport properties of molecule junctions on a chip but also the mechanism of single-molecule-SERS.