Combining Single-Molecule Raman with Molecular Conductance Measurements

The ability to manipulate and characterize individual molecules with atomic-level precision is necessary to develop a thorough understanding of the intricacies of the effects of changes in molecular structure on a range of phenomena such as reaction mechanisms, catalysis, local effective temperatures, surface interactions, and charge transport. Along these lines, the field of molecular-scale electronics has evolved tremendously in recent years: from the initial experiments claiming single-molecule conductance measurements to the development of platforms that provide a detailed understanding of the charge transport properties of these systems. It has now become possible to probe the chemical, structural, mechanical, and electrical properties of single-molecule devices and explore unique functional paradigms for applications. However, continued advances in <i>in situ</i> characterization of a molecular junction are needed to provide detailed information about the molecular configuration and its impact on the charge transport, reactions, and device behavior. Single-molecule conductance and Raman spectroscopies each provide unique perspectives into the behavior of molecular systems and reactions at the single-molecule level. In this talk we will discuss the development and implementation of system designed to simultaneously obtain conductance information and Raman spectra from a molecular junction to provide direct structural and chemical information about a single-molecule junction.<br/><br/>This multi-dimensional information yields repeatable, self-consistent, verification of single-molecule resolution, and allows for detailed analysis of structural and configurational changes of the molecule <i>in situ</i>, and provides new opportunities for identifying molecular substituents, conformations, and the impact of these changes on the transport properties of the molecular systems. We will discuss the correlation between single-molecule binding events and changes in Raman spectra (intensity, modes, etc.) and conductance to explore the possibility of obtaining single-molecule spectra from the molecule bound between two electrodes. We will further explore the utility of this system for <i>in situ</i> characterization of single-molecule devices including electrically-active single-molecule switches, memory devices, and biomolecules.