Improvement of the electronic and transport properties of hybrid bilayer armchair graphene nanoribbon by chemical derivation and out-layer strain: A first principles calculations

Abstract

We investigate the effect of out-layer strain on the electronic and transport properties of chemically functionalized hybrid b-AGNR systems, which are formed by partial hydrogenation and fluorination (or hydrofluorination) in the middle parts of bilayer armchair graphene nanoribbon, using density functional theory and nonequilibrium Green's function techniques. The calculated formation energies show that all hybrid systems have negative formation energies, thus, they are stable with respect to molecular desorption. Especially, the fluorinated hybrid system is more stable than others, due to higher electronegativity of F than H atoms. From calculated band structures, we reveal that the hybrid systems are the semiconductors with band gaps of about 0.09 eV ~ 1.55 eV as function of nanoroad width and out-layer strain. Especially, the band gaps of the hybrid systems with nanoroad width show the order of 3-nanoroad > 5-nanoroad > 1-nanoroad. The calculated I-V curves exhibit that the currents of the hybrid systems as a function of chemical derivation classes increase/decrease with different behavior, while they have similar behavior variations according to out-layer strain. More interestingly, the calculated I-V curves of hybrid b-AFGANR-1-nanoroad system as a function of out-layer strain exhibit negative differential resistance within bias voltage range 0.6 V to 1 V. Prime novelty statementIn this paper, we investigate the effect of out-layer strain on the electronic and transport properties of chemically functionalized hybrid b-AGNR systems, which are formed by partial hydrogenation and fluorination (or hydrofluorination) in the middle parts of bilayer armchair graphene nanoribbon, using density functional theory and nonequilibrium Green's function techniques.The results present that all systems are structurally favorable and are semiconductors with band gaps of about 0.09 eV ~ 1.55 eV as function of nanoroad width and out-layer strain. Especially, the I-V curves of hybrid b-AFGANR-1-nanoroad system as a function of out-layer strain exhibit negative differential resistance within bias voltage range 0.6 V to 1 V.The above results show that hybrid b-AGNR systems would be a promising material for graphene-based electronic devices.