An Electromechanical Spectroscopy for Determining the Atomic-Configuration of Single-Molecule Devices

摘要

With the continued miniaturization of electronic devices, the conventional paradigm for manufacturing electronic devices is reaching physical limitations. Because of this looming boundary, a variety of novel, nanoelectronic platforms are being explored, each of which requires the development of new characterization techniques that can provide insights into their function. Molecules represent a unique class of electronic materials that could potentially extend the development of nanoelectronics. These devices are inherently quantum mechanical in nature, can be designed and constructed with atomic-level precision, are natural 1-dimensional (1D) transport devices, and possess unique opportunities for device fabrication, function, and implementation. The development of molecular-scale electronic devices has made considerable progress over the last decade, and single-molecule transistors, diodes, and wires have all been demonstrated. Despite this remarkable progress, the agreement between theoretically predicted conductance values and those measured experimentally remains limited. One of the primary reasons for these discrepancies lies in the difficulty of experimentally determining the contact geometry and configuration of a molecule when bound between two electrodes. In this report, we describe the development of a novel electromechanical spectroscopic ("alpha" spectroscopy) tool that is capable of determining the most probable binding and contact configurations for a molecular junction at room temperature in solution. These results provide insight into the complex configuration of single-molecule devices that can be used to further improve the agreement between theory and experiment.