Effect of edge chemistry doping on the transport and optical properties for asymmetric armchair-edge graphene nanoribbons under a uniaxial strain

Abstract

The effect of edge n-type nitrogen (N) and p-type oxygen (O) doping on the transport and optical properties for asymmetric 6- and 8-armchair-edge graphene nanoribbons (AGNRs) under a uniaxial strain has been demonstrated in the method of the first-principles density functional theory combined with nonequilibrium Green’s function. The transmission spectra and current–voltage (I–V) curves of the semiconducting 6- and metallic 8-AGNRs have been found to be qualitatively unchanged as the uniaxial strain along the armchair edge (Ac-strain), while the quantitative variations come from the mutual actions of the strain and edge doping. However, the observed semiconductor–metal transition and metal–semiconductor transition in the transport properties for 6- and 8-AGNRs should be mainly from the resonance scattering of the doping edges when the external strain is applied along the zigzag edge (Zz-strain). The distinct variation trends of the system transport properties are well confirmed from the optical absorption spectra. It is believed that the obtained results are of importance in exploiting chemistry at the reactive edges of the asymmetric AGNRs and strain engineering of the nanoelectronic/optoelectronic devices based on AGNRs.