Vapor adsorption limitation of graphene nanoribbons in quasi conductance increment: A NEGF approach

The adsorption of H₂O molecules on Armchair Graphene Nanoribbons (A-GNR) was theoretically studied using Non Equilibrium Green Function (NEGF) formalism to determine Device Density of States (DDOS), Electrostatic Effective Potential (EDP), Conductivity (G) and Current-Voltage (I-V) characteristics. This paper analyzed the performance of semiconducting graphene nanoribbon (N=10), metallic graphene nanoribbon (N=11) and cascade hetero-graphene nanoribbon to consider the effect of H₂O adsorption on GNR and conclude that for low voltage application semiconducting A-GNR will be a better choice over metallic A-GNR and cascade A-GNR. The optimum area for adsorbing maximum number of H₂O molecules on A-GNR has been studied. It has been observed that the increment of quasi conductance resulting sensing performance for limited number of H₂O adsorption. To overcome this problem, a new device model has been proposed.