Between Dec 19, 2024 and Jan 2, 2025, datasets can be submitted to DRUM but will not be processed until after the break. Staff will not be available to answer email during this period, and will not be able to provide DOIs until after Jan 2. If you are in need of a DOI during this period, consider Dryad or OpenICPSR. Submission responses to the UDC may also be delayed during this time.

Browsing by Author "Rothwell, Sara"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Analysis of Turbostatic Graphene grown using chemical vapor deposition of Acetylene on Sapphire
    (2011-04-13) Kelly, Priscilla; Rothwell, Sara; Cohen PhD, Philip I
    Growing graphene on sapphire (Al2O3) by chemical vapor deposition (CVD) of acetylene is thought to introduce less strain on the bonds of graphene compared to other CVD methods. This is due to coincidence lattice matching in sapphire's hexagonal structure that appears after annealing. At this stage of my research, we are testing deposition rates of graphene on sapphire which has led to turbostratic, random and disorganized, growth. This poster demonstrates the properties of our turbostratic graphene from data collected by Raman spectroscopy, Scanning Electron Microscopy (SEM), sheet resistance measurements, and optical imaging.
  • Thumbnail Image
    Item
    Characterization of Graphene Grown Directly on Crystalline Substrates
    (2015-09) Rothwell, Sara
    Graphene has become one of the most popular materials under research, particularly since the 2010 Nobel Prize in Physics. Many visions posit that graphene electronics will be some of the fastest and smallest circuitry physically feasible, however before this becomes reality the scientific community must gain a firm handle on the creation of semiconducting varieties of graphene. In addition, well understood epitaxial growth of graphene on insulating materials will add to the facility of fabricating all-carbon electronics. This thesis presents experimental work detailing the growth of pristine graphene grown on sapphire (GOS) through the thermal decomposition of acetylene, and the electronic characterization of graphene grown on nitrogen-seeded silicon carbide (NG), a semiconducting variety of graphene grown in collaboration with researchers at Georgia Institute of Technology and Rutgers University. GOS displays turbostratic stacking and characteristics of monolayer graphene as analyzed by Raman spectroscopy and atomic force microscopy. Scanning tunneling microscopy characterization of NG illustrates a topography of pleats from 0.5-2 nm tall, 1-4 nm thick, and 1-20 nm long, as well as atomically flat plateaus and other areas of intermixed features. Scanning tunneling spectroscopy measurements across NG features show peaks interpreted as Landau levels induced by strain. Analysis of these Landau levels in coordination with previous characterization concludes that a model employing a bandgap fits best.
  • Thumbnail Image
    Item