ABSTRACT
The physics of single or few layers of graphene sheets was shown to be very unique and vastly different from the physics of bulk layered graphite. While the unique properties of a two-dimensional (2-D) form of graphitic carbon were predicted since 1947, the actual production of graphene samples in 2004, provided an unprecedented opportunity to investigate such unique 2-D material experimentally. Atomic structure of free standing single-layered graphene sheets was investigated using high resolution transmission electron microscopy. The defects were found to modify the electronic structure and the phonons of graphene giving rise to new optical transitions and defect-related phonons. Graphene has been produced by several methods. Some of these approaches including several lithographic, chemical and other synthetic procedures are known to produce microscopic samples of graphene. Another unique approach to prepare graphene is by longitudinal unzipping of single-walled carbon nanotubes and multi-walled carbon nanotubes using oxidation treatment.
