This Nanoscale Exploratory Research (NER) proposal was received in response to NSE, NSF 02-148. This one-year project will explore the possibility of using finite-size single layers of layered transition metal dichalcogenides (LTMDs) as a basic building block for nanoscale electronics. Two-dimensional nanocrystals consisting of single (~0.6 nanometer thick) layers of LTMDs will be prepared on insulating surfaces, and means to contact these layers with macroscopic electrodes will be explored. This research will extend the basic scientific understanding of quasi-2D electronic materials by studying them in their ideal single-sheet form. The research will enhance the basic science of strongly interacting electrons (e.g. superconductivity and charge density waves) in a strictly 2D system. The development of electrically-contacted 2D nanocrystals brings the 2D electron system (2DES) to the surface for the first time (2DESs in semiconductor heterostructures are buried hundreds of nanometers below the surface) allowing new studies of 2DESs using scanned probe techniques. The development of sub-nanometer-thick metallic and semiconducting nanocrystal films will also open new possibilities in nanometer-scale electronics technologies. This project will provide excellent training for undergraduate and graduate students in cutting-edge nanotechnology research. The project is jointly supported by the Divisions of Materials Research and Physics.
This Nanoscale Exploratory Research (NER) proposal was received in response to NSE, NSF 02-148. This one-year project will explore the possibility of constructing electronic circuits from single three-atom-thick layers of materials known as layered transition metal dichalcogenides (LTMDs). In bulk form, LTMDs comprise metals (e.g. niobium diselenide) and semiconductors (e.g. molybdenum disulfide). The metallic phases often exhibit exotic low-temperature behavior, such as superconductivity and charge density waves. This program offers a new opportunity to study these complex materials in their most basic single-sheet form. New experiments will be made possible, such as the imaging of the electronic states in the material using scanning tunneling microscopy simultaneous to electronic measurements. These ultra-thin metallic and semiconducting films may find application in electronics as interconnects, transistors, sensors, etc., and may also be used to interface with nanoscale electronic elements, such as molecular wires. This project will provide excellent training for undergraduate and graduate students in cutting-edge nanotechnology research. The project is jointly supported by the Divisions of Materials Research and Physics.