Graphene, discovered by Geim and Novoselov 1, is a material composed of a single layer of sp2 hybridized pure carbon atoms arranged in a regular hexagonal honeycomb pattern as shown in Figure 1. This material has unique mechanical, electrical, chemical and thermal properties that stimulate enormous research interest.2,3 Graphene can also be considered as a building block for the formation of fullerenes, carbon fibers, carbon nanotubes and graphite.1Fig. 1. 2D Structure of Single Layer Graphene As we stated earlier, graphene is made up of the lattice of sp2 hybridized carbon atoms. In the carbon atom, there are three orbitals, namely 2s, 2px and 2py, which are responsible for forming the covalent sigma bond between other adjacent carbon atoms to form the 2D structure of graphene. However, the other p orbital, 2pz, which is out of the plane of the structure forms the pi bonds. The energy of the pi bonding orbitals in graphene is close to the Fermi energy level. Therefore, it provides delocalized states that are responsible for the electrical conductivity of graphene.4,5 However, for the few layers of graphene the orientation of these pi orbitals changes, which is why the electronic properties of graphene strongly depend on the number of graphene layers. Therefore, only single-layer and double-layer graphene are zero band gap semiconductors, meaning that there is no energy gap between the valence band and the conduction band. On the other hand, in the case of few-layer graphene, the conduction and valence bands start to overlap. Due to this type of property, graphene exhibits unique electrical properties such as high carrier mobility, a stable 2D crystalline structure, and the ability to perform ballistic transport at room temperature.6,7In addition to electrical properties, layered graphene single layer has other properties that differ from a few layers of graphene. For example,