MBE-Grown Cubic ZnS Nanowires

Ultrathin ZnS nanowires (NWs) were grown on a sapphire (0001) substrate at 430°C by the molecular-beam epitaxy (MBE) technique using self-assembled Au droplets as the catalyst. It was found that these NWs mainly consist of the cubic phase but a small portion was in the hexagonal phase. The analysis of the temperature-dependent band-edge (BE) emission of these NWs and that of a ZnS thin film revealed that the energy shift of the interband transition on temperature in ZnS is mainly attributed to the electron–phonon interactions. The observed blue shift of the BE emission of ZnS NWs could be quantitatively explained by the confinement of the excited excitons in the NW geometry.