One-step growth of ZnO/ZnS core-shell nanowires by thermal evaporation

ZnO/ZnS core-shell nanowires with the wurtzite structure have been grown using a simple catalyst-free thermal evaporation technique. The ZnO/ZnS core-shell nanowires are as long as several tens of micrometers, the thickness of the wires is about 1 mu m at the bottom and 50 nm at the top respectively, and the thickness of the core ZnO is about 30 nm near the top of the wires. A high-magnification transmission electron microscope image of a single nanowire reveals a clear ZnO/ZnS interface. The photoluminescence spectrum of the products exhibits two peaks at about 400 and 410 nm respectively.