Modeling and Design of Beyond the Roadmap Materials and Devices: Nanowires, Nanotubes, and Molecules

As device dimensions shrink to the molecular scale, theory and modeling assume an ever greater role. The analytical ability to experimentally determine the chemistry and geometry for individual molecular devices does not yet exist. Heroic experiments can be required to fabricate devices at this scale. Theory and modeling can relatively quickly explore the effect of the microscopic chemistry and geometry determining the electron and hole transport. The performance metrics of extremely scaled, difficult-to-fabricate designs can be compared. Theory and modeling can identify promising directions and provide physical understanding of experimental results. We apply theory and modeling to understand, analyze, design and optimize CNT, nanowire, and molecular based devices. The theory, modeling and design of chemically and biologically assembled carbon nanotubes (CNTs) is described. A CNT-molecular-resonant tunneling device is analyzed. Interface geometry is shown to have a large effect on the electron and hole transport. The intrinsic performance metrics of a CNT field effect transistor on insulator (COIFET) are determined.