Self-assembled three-dimensional structures of single-crystalline ZnS submicrotubes formed by coalescence of ZnS nanowires

Self-assembled three-dimensional (3D) dandelionlike ZnS structures have been successfully synthesized by a simple thermochemical process using ZnS and Ge powders as the source material. The as-synthesized dandelionlike structures consist of radially aligned ZnS submicrotubes with well-faceted hexagonal cross sections, which are formed by the coalescence of neighboring ZnS nanowires. A two-step self-assembly process was proposed to explain the formation mechanism. The as-synthesized 3D dandelionlike ZnS structures show strong green emission centered at about 550 nm as well as a weak emission at 720 nm.