Theoretical models of ZnS nanoclusters and nanotubes: First-principles calculations

The structural characters, energetics and electronic properties of zinc sulfide (ZnS) nanostructures, including (ZnS)n nanoclusters (n=2–48,60)(n=2–48,60), single-walled (SW-) ZnS nanotubes (ZnSNTs) and double-walled (DW-) ZnSNT, were explored by performing first-principles calculations. We found that the formation energies of (ZnS)n bubble clusters are proportional to the inverse of the cluster size, n−1n−1,which is understandable in terms of a simple model. Both the (ZnS)60 double bubble cluster and DW-ZnSNT are energetically more favorable than the (ZnS)n bubble clusters and SW-ZnSNTs, among which DW-ZnSNT is energetically the most favorable. ZnS nanoclusters have stronger quantum confinement effects than ZnSNTs.