First principles modeling of MoS nanowires via condensation of MoS clusters and the effect of iodine doping on structural and electronic properties

By employing first principles DFT calculations, we propose a new stable model for MoS nanowires (NWs) obtained by condensing tetrahedral MoS clusters rather than octahedral MoS clusters, which are known as magic clusters in the Mo-S polyhedral cluster family. The pristine NW is found to be metallic and its local structure and physical properties can be tuned by doping of iodine atoms. This doping increases the number of Mo-Mo bonds in the NW, thus, Mo tetrahedra are initially fused to the Mo octahedron, and then, to the Mo dodecahedron. Further, a close correlation among the Mo-Mo bonding in the local structure, mechanical and electronic properties, is observed from our study. Finally, the stability of the pristine and iodine doped MoSI NW structures obtained from condensation of Mo tetrahedra are found to be quite comparable with that of already reported MoSI NWs with Mo octahedra as building blocks.