Enhancing metallicity in zigzag graphene nanoribbons with adsorbed/substitutionally doped copper atoms

Width dependent properties of Cu doped zigzag graphene nanoribbons (ZGNR) have been examined with density functional theory. We considered Cu as an adsorbed atom as well as a substitutional dopant (SD) at edge and the centre of ZGNR. It is revealed that adsorption and SD affect the stability of the ribbons in a different manner. Adsorption is energetically favorable whereas SD results in stronger binding of Cu atom with ZGNR. Edge is found as the preferred site for both types of Cu doping. The electronic property of ZGNR is effectively modified by the presence of Cu atoms and enhanced metallicity is observed in nanoribbons with substitutional Cu impurity. The observed high metallicity of Cu doped ZGNR is crucial particularly for the nanoelectronic interconnects.