Electronic Devices from Nanopatterned Epitaxial Graphene and Reduced Graphite Oxide
Since its advent, graphene, an atomically thin sheet of graphite, has been intently investigated due to its unique electronic properties and ballistic electron transport. Our group has been actively involved in studying graphene, graphene oxide and more recently graphene intercalation compounds.
Laser Induced Graphite Oxide Reduction
As the motivation for reproducible, inexpensive growth strategies for macroscale graphene production continues to intensify, synthetic chemistry approaches have emerged as appealing alternatives to methods that require (ultra) high vacuum pressures or cleanroom facilities. A promising precursor for graphene is graphite oxide. Graphite oxide (GO) is an oxidized form of graphite, which can be readily exfoliated in water to form monolayers known as graphene oxide. In our group we developed a technique to produce graphene features from direct laser irradiation of GO using both continuous wave (CW) and pulsed laser irradiation in an inert gas atmosphere. These laser-induced graphene features are characterized by the presence of a distinct 2D band in the Raman spectra. This can be fit with a single Lorentzian and is similar to that observed for single-layer exfoliated graphene (EG) and epitaxial graphene.
Probing the Epitaxial Graphene Growth Mechanism
The detailed mechanisms governing the growth of epitaxial graphene on SiC are not well understood. We are therefore examining the growth process by monitoring the production and release of molecules as a function of growth temperature and duration on both the C- and Si-terminated surfaces of pristine and hydrogen etched samples under ultrahigh vacuum conditions. Specifically, we used in-situ quadrupole mass spectrometry to investigate the chemical species produced and desorbed during the heating of SiC.