Density functional theory study on the influence of zero-mode on the metallicity of stanene nanoribbons

The customizable realization of metallic properties in low-dimensional materials can greatly enhance their potential applications as connecting devices. In stanene nanoribbons, the introduction of Zero-modes induces metallic behavior. By forming two new Sn-Sn bonds within each stanene nanoribbon unit, the graphene-like Zero-mode metallic band is broadened. This study successfully regulates the quasi-one-dimensional metallicity of stanene nanoribbons through substitutional doping of a pair of atoms within the pentagonal rings. The results indicate that the formation of two Sn-Sn bonds slightly reduces the average atomic binding energy of the stanene nanoribbons. Compared to p-type doping systems, the covalency of the connecting bonds between the two dopant atoms is stronger in systems doped with elements from the same group as Sn or with n-type dopants. Among the systems analyzed, MSnNR#Ga achieves the highest metallic bandwidth of W = 176.13 meV, approximately 56 times that of intrinsic stanene nanoribbons.