Overview of Wolkow Group Research Plan

Our goal is to enable fabrication of molecular devices, primarily hybrid structures made from organic molecules on the surface of silicon. This approach combines the powerful and versatile properties of silicon, which has ideal properties for electronic devices, with organic molecules that have subtle and highly discriminating properties that offer a wide range of function. We believe that the enormous challenges facing molecules-as-devices can most likely be overcome if a hybrid silicon-organic molecule strategy is adopted. In particular, the connection of a molecular device to the outside world can be largely simplified when it is mounted on a silicon surface.

To approach these goals, we develop and use tools which allow imaging and manipulation of individual atoms and molecules on silicon. The key is the scanning-tunneling microscope (STM), which permits the study and engineering of concepts relevant to molecular devices. In addition to STMs and a wide range of complementary material characterization tools, we develop and use theroricetical methods for modeling properties of hybrid molecule-silicon nanostructures..

To build working molecular devices, we focus on understanding the fundamental processes that influence their construction and operation. There is much to learn before molecular devices become practical. In particular, we seek to understand the nature and influence of each atom and chemical bond in a device structure, as well as the influence on molecular structure upon adsorption. To permit information to move in and out of the device, the electrical transport properties of tailored organic-silicon must be characterized. In addition, practical devices will require methods that are enormously faster than atom-by-atom assembly, so methods and processes that allow the rapid self-organization of molecular structures on silicon will be investigated. Functional devices also require an understanding of transduction mechanisms that provide an electrical signal from the change in a molecular device caused by, for example, the detection of a target molecule in a molecular sensing device, or by the absorption or emission of photons. All these phenomena must be clearly understood, as they are the “design rules” that are required to allow the reliable and predictable manufacture of practical molecular devices; all these areas of research are of keen interest to our group.