Engineering the Electronic Structure of Tin Sulfide Nanoribbons: A Computational Study

We have investigated the structure, stability, and the electronic properties of bare and edge-hydrogenated tin sulfide nanoribbons (SnSNRs) using first-principles density functional theory calculation. In contrast with the 2D sheet of SnS, which is an indirect band-gap semiconductor, bare 1D SnSNRs are either metallic (in the case of zigzag (zz) edge termination) or direct/indirect band-gap semiconductors (in the case of armchair (ac) edge termination) in nature. The edge-hydrogenated zigzag nanoribbons are direct band-gap semiconductors and the edge-hydrogenated armchair nanoribbons are direct/indirect band-gap semiconductors depending on width. The edge-hydrogenated nanoribbons have low edge energies and quite high mechanical strength, indicating their energetic as well as mechanical stabilities. Moreover, armchair SnSNRs can tolerate very high expansive strain (∼65%) due to their morphological transformation from puckered to buckled ones. On the application of uniaxial strain (both expansive and compressive), the edge-hydrogenated SnSNRs provide interesting strain-induced band-gap variation. In addition, an in-plane semiconductor–metal Schottky junction has been made by conjunction of edge-hydrogenated and bare zz-SnSNRs, which show good rectifying current–voltage characteristics