Wc / Graphene Complex Electronic Structure And Electronic Transport Properties

The electronic structures and configurations of the WC-absorbed graphene, platinum-adsorbed graphene, and platinum-adsorbed tungsten carbide systems were systematically investigated by the density functional theory (DFT) plane-wave pseudopotentials method. Also, their adsorption characteristics and stabilities were evaluated by the obtained electronic properties and binding energies. The calculated results indicated that in WC-absorbed graphene systems the bonding interaction can be noted for the interface of the W-terminated CW/graphene configuration; however, only the van der Waals interaction for the C-terminated WC/graphene structure. This results show an energetically preferred W-terminated CW/graphene configuration. Furthermore, in the WC-adsorbed multi-layer graphene system, W-terminated CW/multi-graphene possesses a bonding interaction between the interface layers, but only van der Waals forces can be noted between the interface two layers of the C-terminated WC/multi-graphene configuration. Also, in the W-terminated adsorbed graphene system, the second graphene layer located from the interface has somewhat contribution to the system stability. For the Pt-adsorbed WC system, the interface interaction in the hcp-Pt/WC configuration occurs almost between the interface two layers, but for the fcc-Pt/CW configuration, it is between the Pt layer and all WC layers.In this thesis, we also studied the electronic transport properties of the WC/graphene system, which was set to the intermediate scattering region of double electrode system with the metal nickel as electrodes. The computed results demonstrated that the spin-up electrons is preferred to the electron transport at zero bias. With a certain bias, the electron spin has relatively less effect on i-V curve.